Silver nanoparticles (Ag NPs) have attracted much attention in the field of biomaterials due to their excellent antibacterial property. However, the reducing and stabilizing agents used for chemical reduction of Ag NPs are usually toxic and may lead to water pollution. In this work, Ag NPs (31.2 nm in diameter) was prepared by using the extract of an agricultural waste, straw, as the reducing and stabilizing agent. Experimental analysis revealed that the straw extract contains lignin, the structure of which possess phenolic hydroxyl and methoxy groups, facilitating the reduction of silver salts into Ag NPs. The surfaces of Ag NPs were negatively charged due to the encapsulation of a thin layer of lignin molecules that prevented their aggregation. Interestingly, after adding the prepared Ag NPs into the precursor solution of acrylamide, free radical polymerization was triggered without the need of extra heating or light irradiation, resulting in the rapidly formation of an Ag NPs-polyacrylamide composite hydrogel. The inhibition zone test proved that the composite hydrogel possesses excellent antibacterial ability due to the presence of Ag NPs. The prepared hydrogel may find potential applications in fabrication of biomedical materials, such as antibacterial dressings.

Large-scale underground projects require precise in-situ stress information, and the acoustic emission (AE) Kaiser effect method currently provide lower costs and streamlined procedures. In this method, the accuracy and speed of Kaiser point identification are crucial. Thus, the integration of chaos theory and machine learning for the precise and rapid identification of Kaiser points constitutes the objective of the study. The intelligent model of the AE partitioned areas identification was established by phase space reconstruction (PSR), genetic algorithm (GA), and support vector machine (SVM). Then, the plots of model classification results were made to identify Kaiser points. We refer to this method of identifying Kaiser points as “The Partitioning Plot Method based on PSR-GA-SVM” (PPPGS). The PSR-GA-SVM model demonstrated outstanding performance, achieving a 94.37% accuracy rate on the test set, with other evaluation metrics also indicating exceptional performance. The PPPGS identified Kaiser points similar to the tangent-intersection method, with greater accuracy. Furthermore, in the classification model's feature importance score, the fractal dimension extracted by PSR ranked second after accumulated AE counts, confirming its importance and reliability as a classification feature. To validate practicability, the PPPGS were applied to in-situ stress measurement at a phosphate mine in Guizhou Weng'an, China, demonstrating good performance.

The environment-friendly and efficient selective separation of chalcopyrite and molybdenite presents a challenge in mineral processing. In this study, Gum Arabic (GA) was initially proposed as a novel depressant for the selective separation of molybdenite from chalcopyrite in flotation processes. The micro-flotation results indicated that GA exhibited a stronger inhibitory capacity towards molybdenite rather than chalcopyrite. At pH 8.0 with the addition of 20 mg/L GA, the recovery of chalcopyrite in the concentrate obtained from mixed minerals flotation was 67.49% higher than that of molybdenite. Furthermore, the mechanism of GA was systematically investigated by various surface characterization techniques. The contact angle tests indicated that the hydrophobicity of molybdenite surface significantly decreased after GA treatment, while there was no apparent change in the hydrophobicity of chalcopyrite surface. The Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) results indicate that the interaction force between GA and chalcopyrite was weak. In contrast, GA primarily adsorbed onto the surface of molybdenite through chemical chelation, with hydrogen bonding and hydrophobic interactions also possibly contributing. Pre-adsorbed GA could prevent BX from adsorbing onto the molybdenite. Scanning electron microscopy energy dispersive spectroscopy (SEM-EDS) analysis further indicated that GA primarily adsorbed onto the "face" of molybdenite rather than the "edge". Therefore, GA could be a promising molybdenite depressant and provide flotation separation of Cu–Mo.

Weathering steel has excellent corrosion resistance and is widely used in bridges, towers, railways, highways and other engineering that are exposed to the atmosphere for long periods of time. However, before forming stable rust layer, weathering steel is prone to issues such as rust liquid sagging and spattering, leading to environmental pollution and city appearance concerns. These factors limit the application and development of weathering steel. In this study, we developed a rapid and environmentally friendly method by introducing alloying elements, specifically investigating the role of tin (Sn) in the rapid stabilization of the rust layer in a marine atmospheric environment. In this work, we explored the rust layer formed on weathering low-alloy steel exposed to prolonged outdoor conditions and laboratory immersion experiments by EPMA, micro-Raman, XPS and electrochemical measurements. The results showed an optimal synergistic effect between Sn and Cr, which facilitated the accelerated densification of the rust layer. This beneficial effect contributed to enhancing the ability of the rust layer to resist Cl- erosion and improving the protection performance of the rust layer.

Bioleaching is confronted with problems, such as low efficiency, long production cycle length and vegetation destruction. In order to solve problems above, fly ash and low-grade copper sulfide ores were used to investigate bioleaching behaviors and bacterial community succession. Results showed that copper recovery, bacterial concentration, total proportion of main leaching bacteria including Acidithiobacillus ferrooxidans, Acidibacillus ferrooxidans and Leptospirillum ferriphilum, were improved though using appropriate dosage of fly ash. The maximum copper recovery of 79.87% and bacterial concentration of 7.08 × 107 cells·mL−1 were obtained after using 0.8 g·L−1 fly ash. Exclusive precipitation including Zn(Fe3(SO4)2(OH)6)2 and Mg(Fe3(SO4)2(OH)6)2 was found in sample added 0.8 g·L−1 fly ash, which reduced the effect of hazardous ions on bacteria and thus contributing to bacterial proliferation. Bacterial community structure was differentiated, which indicated difference between original inoculation and sample used 0.8 g·L−1 fly ash was less than others. Total proportion of the three microorganism above accounted for more than 95% in all tests, especially in sample with 0.8 g·L-1 fly ash up to 99.81%. Cl- and Ag+ contained in fly ash can act as catalytic agent, which contributed to conversion from smooth and dense passivation layer to sparse and scattered one, and therefore improving contact between ores, lixiviant and bacteria. Using appropriate dosage of fly ash showed prospects in bioleaching.

The demand for oil casing steel with ultra-high strength and excellent impact toughness for safe application in ultra-deep wells is pressing. Aiming at improving the combination of strength, ductility and impact toughness, the designed Cr-Mo-V micro-alloyed oil casing steel was quenched at 800°C, 900°C, 1000°C, followed by tempering at 600°C, 680°C, 760°C respectively to obtain distinct microstructures. The results showed that the microstructure of the samples quenched at 800°C followed by tempering consisted of untransformed ferrite and large undissolved carbides, which deteriorated both tensile strength and impact toughness significantly. For other conditions, the nucleated carbides and the boundaries are key factors that balance the tensile strength from 1226 MPa to 971 MPa and impact toughness from 65 J to 236 J. From the perspective of carbide, optimal precipitation strengthening is achieved with a small carbide size obtained by low tempering temperature of 600℃, while larger-sized carbides would significantly soften the matrix to improve the toughness but deteriorate the tensile strength. Additionally, an increase in prior austenite grain size with the corresponding enlarged sub-boundaries obtained by high quenching temperature substantially diminishes grain refinement strengthening, dislocation strengthening and the energy absorbed in crack propagation process, which is unfavorable to strength and toughness.

Silver selenide (Ag2Se) stands out as a promising thermoelectric (TE) material, particularly for applications near room temperatures. This research presents a novel approach for the fabrication of bulk Ag2Se samples at a relatively low temperature (170 °C) using the cold sintering process (CSP) with AgNO3 solution as a transient liquid agent. The effect of AgNO3 addition during CSP on the microstructure and TE properties was investigated. The results from XRD, SEM, TEM and EDS analyses showed that the introduction of AgNO3 solution induced the formation of Ag nano-precipitates within the Ag2Se matrix. Although the nano-precipitates do not affect the phase and crystal structure of orthorhombic β-Ag2Se, they suppressed crystal growth, leading to reduced crystallite sizes. The samples containing Ag nano-precipitates also exhibited higher porosity and low bulk density. Consequently, these effects contributed to significantly enhanced electrical conductivity and a slight decrease in the Seebeck coefficient when small Ag concentrations were incorporated. This resulted in an improved average power factor from ~1540 µW m-1K-2 for pure Ag2Se to ~1670 µW m-1K-2 for Ag2Se with additional Ag precipitates. However, excessive Ag addition had a detrimental effect on the power factor. Furthermore, thermal conductivity was effectively suppressed in Ag2Se fabricated using AgNO3-assisted CSP, attributed to enhanced phonon scattering at crystal interfaces, pores, and Ag nano-precipitates. The highest figure-of-merit (zT) of 0.92 at 300 K was achieved for the Ag2Se with 0.5% Ag during CSP fabrication, equivalent to >20% improvement compared to the controlled Ag2Se without extra Ag solution. Thus, the process outlined in this study presents an effective strategy to tailor the microstructure of bulk Ag2Se and enhance its TE performance at room temperature.

Facing the complex variable high-temperature environment, electromagnetic wave (EMW) absorbing materials maintaining high stability and satisfying absorbing properties is essential. In this study, the TiN/Fe2N/C composite materials were synthesized by electrostatic spinning and high-temperature nitridation process. The TiN/Fe2N/C fibers constructed a well-developed conductive network generating considerable conduction loss. The heterogeneous interfaces between different components generated lots of significant interfacial polarization. Thanks to the synergistic effect of stable dielectric loss and optimized impedance matching, the TiN/Fe2N/C composite materials exhibited the stable and excellent absorption performance across a wide temperature range (293 K-453 K). Moreover, TiN/Fe2N/C-15 achieved a minimum reflection loss (RL) of -48.01 dB and the effective absorption bandwidth (EAB) of 3.64 GHz at 2.1 mm and 373 K. This work may offer new insights for exploring high-efficiency and stabile EMW absorbing materials under complex variable high-temperature conditions.

The equilibrium phase relations of the CaO-SiO2-TiO2-5 wt.% Fe3O4 system were experimentally investigated at 1400 °C in air. High-temperature equilibration-quenching techniques were employed in an electric MoSi2 resistance heated furnace, with phase composition analysis conducted using an Electron Probe Micro-Analyzer and X-ray diffraction. A single liquid region, liquid-solid phase equilibrium including liquid-tridymite, liquid-rutile, liquid-perovskite, liquid-wollastonite, as well as three-phase equilibrium of liquid-tridymite-rutile and liquid-rutile-perovskite are found. The 1400 °C isothermal sections of the CaO-SiO2-TiO2-5 wt.% Fe3O4 system in air were projected. The present experimental results exhibited good agreement with the calculation results obtained from FactSage.

Nowadays, force sensors play an important role in industrial production, electronic information, medical health and many other fields. Two-dimensional material-based filed effect transistor (2D-FET) sensors are competitive with nano-level size, lower power consumption and accurate response. However, few of them has the capability of impulse detection, which is a path function, expressing the cumulative effect of the force on the particle over a period of time. Herein, we fabricated the flexible PMMA gate dielectric MoS2-FET for force and impulse sensor application. We systematically investigated the responses of the sensor to constant force and varying forces, and achieved the conversion factors of the drain current signals (Ids) to the detected impulse (I ⃗). The applied force was detected and recorded by Ids with a low power consumption of ~30 nW. The sensitivity of the device can reach ~8000% and the 4×1 sensor array is able to detect and locate the normal force applied on it. Moreover, there was almost no performance loss for the device as left in the air for two months.

The control of oxygen is paramount in achieving high-performance titanium (Ti) parts by powder metallurgy such as metal injection molding (MIM). Herein, hydride-dehydride (HDH) Ti powders were modified by pre-oxidation to investigate the effect of oxygen variation on the characteristics of oxide layer on the particle surface and its resultant color feature. The results showed that the thickness and Ti dioxide level of the oxide layer on the HDH Ti powders were increased with the oxygen content, leading to the transition of color appearance from grey, brown to blue. In addition, the development of oxygen content was comprehensively studied during the MIM process using the gas-atomized (GA) Ti-6Al-4V powders. Particularly, the oxygen variation in the form of oxide layer, the change of oxygen content in the powders and the relevant parts were investigated during the process of kneading, injection, debinding and sintering. The oxygen variation was mainly concentrated in the sintering stage, and the content was increased with the increase of sintering temperature. This work provides a piece of valuable information on oxygen detecting, control and manipulation for the powder and processing in the industry of Ti powder metallurgy.

Simultaneously achieving high strength and high conductivity in Cu-Ni-Si alloys poses a significant challenge, which greatly constrains its applications in the electronics industry. This paper offers a new pathway for the improvement of properties, by preparation of nanometer lamellar discontinuous precipitates (DPs) arranged with the approximate same direction through a combination of deformation-aging and cold rolling process. The strengthening effect is mainly attributed to nanometer-lamellar DPs strengthening and dislocation strengthening mechanism. The accumulation of dislocations at the interface between nanometer lamellar DPs and matrix during cold deformation process can results in the decrease of dislocation density inside the matrix grains, leading to the acceptably slight reduction of electrical conductivity during cold rolling. The alloy exhibits an electrical conductivity of 45.32 %IACS, a tensile strength of 882.67 MPa, and a yield strength of 811.33 MPa by this method. This study can provide a guidance for the composition and microstructure design of Cu-Ni-Si alloy in the future, by controlling the morphology and distribution of DPs.

The effects of the Al content on the precipitation of nanoprecipitates, the growth of prior austenite grain (PAG), and the impact toughness in simulated coarse-grained heat-affected zones (CGHAZs) of two experimental shipbuilding steels after subject to high-heat input welding at 400 kJ·cm⁻¹ are studied. The base metals (BMs) of both steels contain three types of precipitates: Type-cubic (Ti, Nb)(C, N); Type Ⅱ-precipitate with cubic (Ti, Nb)(C, N) core and Nb-rich cap; and Type Ⅲ-ellipsoidal Nb-rich precipitate. In the BM of 60Al and 160Al steels, the number densities of the precipitates are 11.37 × 105 mm⁻² and 13.88 × 105 mm⁻², respectively. In 60Al steel, Type Ⅲ precipitates make up 38.12% of the total, whereas in 160Al steel, they account for only 6.39%. This variance in the amount of Type Ⅲ precipitates in 60Al steel reduces the pinning effect at the elevated temperature of CGHAZ, thereby facilitating PAG growth. The average PAG sizes in the CGHAZ of 60Al and 160Al steels are 189.73 μm and 174.7 μm, respectively. In 60Al steel, the low lattice mismatch between Cu2S, TiN and γ-Al2O3 facilitates the precipitation of Cu2S and TiN onto γ-Al2O3 during the welding, which decreases the number density of independently precipitated (Ti, Nb)(C, N) particles but increases the number density of γ-Al2O3-TiN-Cu2S particles. Thus, abnormally large PAGs are found in the CGHAZ of 60Al steel, reaching a maximum size of 1 mm. This presence of abnormally large PAGs in the CGHAZ of 60Al steel greatly reduces the microstructure homogeneity, consequently decreasing the impact toughness from 134 (0.016wt% Al) to 54 J (0.006wt% Al) at −40°C.

This study investigated the microstructure evolution of a cold-rolled (CR) and intercritical (IA) annealed medium-Mn steel (Fe-0.10C-5Mn) during uniaxial tensile test. In-situ observations under scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD) analysis were conducted to characterize the progressive TRIP (Transformation-Induced Plasticity) process and the associated fracture initiation mechanisms. These findings were discussed with local strain measurements by digital image correlation (DIC). The results indicated that the Lüders band formation in the steel was limited to a strain of 1.5%, mainly due to the the transformation of relatively large-sized blocky retained austenite (RA) into α’-martensite, retarding the yielding. The small-sized RA exhibited higher stability, progressively transforming into martensite and endowed stably extended Portevin-Le Chatelier (PLC) effect. The volume fraction of RA displaying a gradual decrease from 26.8% to 8.2% before fracture. In the late deformation stage, fracture initiation primarily occurred at the, austenite/martensite and ferrite/martensite interfaces as well as the rupture of ferrite phase.

Calcium ferrite is recognized as a potential green and efficient functional material due to its advantages of magnetism, electrochemistry, catalysis, and biocompatibility in the fields of materials chemistry, environmental engineering, and biomedicine. Therefore, it is essential to systematically summarize the obtained research results and analyze new perspectives on calcium ferrite and its composite materials. Based on the presented studies on calcium ferrite and its composite materials, the types and structures of the crystal are summarized. In addition, the current application technologies and theoretical mechanisms with various properties in different fields are elucidated. Moreover, the various preparation methods of it and its composites are elaborated in detail. Above all, the advantages and disadvantages of the synthesis methods of calcium ferrite and its composite materials are discussed, and the main problems existing and the challenges faced in practical production in the future are pointed out. Furthermore, the key future research directions of calcium ferrite and its composite materials have prospected from the potential application technologies to provide references for its synthesis and efficient utilization.

This study investigated the effect of konjac glucomannan (KGM) on the flotation separation of calcite and scheelite. Micro-flotation tests showed that the floatability of calcite decreased significantly under the action of 50 mg/L KGM, while the impact on scheelite was negligible, resulting in a recovery difference of 82.53%. Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM) analyses indicated that KGM was selectively adsorbed on the calcite surface. The zeta potential and UV-visible absorption spectroscopy test results revealed that KGM prevented the adsorption of sodium oleate on the calcite surface. X-ray photoelectron spectroscopy (XPS) analysis further confirmed that KGM achieved chemical adsorption on the calcite surface and formed Ca(OH)2. The density functional theory (DFT) simulation results were consistent with the flotation tests and measurement analyses, demonstrating that KGM had stronger adsorption performance on the calcite surface. This study provides a pathway for more sustainable and cost-effective mineral processing by utilizing the unique properties of biopolymers such as KGM to separate valuable minerals from gangue minerals.

Zinc oxide (ZnO) is an important functional semiconductor with wide direct bandgap about 3.37 eV. The solvothermal reaction has been usually employed to synthesize ZnO micro/nanostructures, which is inexpensive, simple and easy to implement. In addition, ZnO morphology engineering is desirable by changing slight condition in the reaction process, especially at room temperature. In this work, ZnO micro/nanostructures were synthesized in solution by changing amounts of ammonia addition at low temperature (even at room temperature). Ammonia can form Zn2+ complexes in precursor to control the reaction rate for morphology engineering of ZnO, such as nanoparticles, nanosheets, microflowers, and single crystals. Finally, the obtained ZnO was taken in optoelectronic application of ultraviolet detectors.

As a mathematical analysis method, fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties. It has been applied to shape characterization at various scales and dimensions in metal materials. Conventional methods make it difficult to quantitatively describe the relationship between the regular characteristics of surface and interfaces and properties in the study of metal materials. However, fractal analysis can quantitatively describe the shape characteristics of metal materials and then establish the quantitative relationship between these shape characteristics and various properties of metal materials. From the perspective of two-dimensional planes and three-dimensional curved surfaces, this paper reviews the current research status of fractal analysis in metal precipitate interfaces, metal grain boundary interfaces, metal deposited film surfaces, metal fracture surfaces, metal machined surfaces and metal wear surfaces. The relationship between the fractal dimension of the surface and interface and the properties of metal materials is summarized. Starting from three perspectives of fractal analysis, which are the research scopes, image acquisition methods and calculation methods, this paper points out the direction of research on fractal analysis of surface and interfaces of metal materials that need to be developed. It is believed that revealing the deep mechanism between the fractal dimension of the surface and interface and the properties of metal materials will be the key research direction of fractal analysis of metal materials in the future.

The wave-absorbing materials are kinds of special electromagnetic functional materials and have been widely used in electromagnetic pollution control and military fields. In-situ integrated hierarchical structure construction is thought as a promising route to improve the microwave absorption performance of the materials. In the present work, layer-structured Co-MOFs precursors were grown in-situ on the surface of carbon fibers with the hydrothermal method. After annealed at 500 °C under Ar atmosphere, a novel multiscale hierarchical composites (Co@C/CF) were obtained with the support of carbon fibers, keeping the flower-like structure. SEM, TEM, XRD, Raman and XPS were performed to analyze the microstructure and composition of the hierarchical structure, and the microwave absorption performance of the Co@C/CF composites were investigated. The results showed that the growth of the flower-like structure on the surface of carbon fiber was closely related to the metal-to-ligand ratio. The optimized Co@C /CF flower-like composites achieved the best reflection loss of -55.7dB in the low frequency band of 6-8 GHz at the thickness of 2.8mm, with the corresponding EAB of 2.1 GHz. The EAB of 3.24 GHz was achieved in the high frequency range of 12-16 GHz when the thickness was 1.5 mm. The excellent microwave absorption performance was ascribed to the introduction of magnetic components and the construction of the unique structure. The flower-like structure not only balanced the impedance of the fibers themselves, but also extended the propagation path of the microwave and then increased the multiple reflection losses. This work provides a convenient method for the design and development of wave-absorbing composites with in-situ integrated structure.

In this work, we realized a room-temperature NO2 gas sensor based on the Pt-loaded nano-porous GaN sensing material by thermal reduction method and co-reduction with the catalyzing of polyols. The gas sensor gained excellent sensitivity to NO2 of concentration range from 200 ppm to 100 ppb benefiting from the loading of Pt nano-particles, exhibited short response time (22 s) and recovery time (170 s) to 100 ppm NO2 at room temperature with excellent selectivity to NO2 compared to other gases. This phenomenon is attributed to the spillover effect and the synergic electronic interaction with semiconductor materials of Pt which not only provided more electrons for the adsorption of NO2 molecules but also occupied effective sites causing the poor sites for other gases. The low detection limit of Pt/NP-GaN is 100 ppb and the gas sensor still had fast response 70 days after fabrication. Besides, the gas sensing mechanism of gas sensor is further elaborated to figure out the reason leading to the improvement of properties. The significant spillover impact and oxygen dissociation of Pt provided advantages to its synergic electronic interaction with semiconductor materials leading to the development of gas properties of gas sensors.

The urgent need for integrated molding and sintering across various industries has inspired the development of additive manufacturing (AM) ceramics. Among the different AM technologies, direct laser additive manufacturing (DLAM) stands out as a group of highly promising technology for flexibly manufacturing ceramics without molds and adhesives in a single step. Over the last decade, significant and encouraging progress has been accomplished in DLAM of high-performance ceramics, including Al2O3, ZrO2, Al2O3/ZrO2, SiC, and others. However, high-performance ceramics directly fabricated by DLAM face challenges such as formation of pores and cracks and resultant low mechanical properties, hindering their practical application in high-end equipment. Further improvements are necessary before they can be widely adopted. Methods such as field-assisted techniques and post-processing can be employed to address these challenges, but a more systematic review is needed. This work aims to critically review the advancements in selective laser sintering/melting (SLS/SLM) and laser directed energy deposition (LDED) for various ceramic material systems. Additionally, it provides an overview of the current challenges, future research opportunities, and potential applications associated with DLAM of high-performance ceramics.

Exploring efficient and nonprecious metal electrocatalysts of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is crucial for developing rechargeable zinc-air batteries (ZABs). Herein, an alloying-degree control strategy is employed to fabricate nitrogen-doped carbon sphere (NCS) decorated with dual-phase Co/Co7Fe3 heterojunctions (CoFe@NCS). The phase composition of materials has been adjusted by controlling the alloying degree. The optimal CoFe0.08@NCS electrocatalyst displays a half-wave potential of 0.80 V for ORR and an overpotential of 283 mV at 10 mA cm-2 for OER in an alkaline electrolyte. The intriguing bifunctional electrocatalytic activity and durability is attributed to the hierarchically porous structure and interfacial electron coupling of highly-active Co7Fe3 alloy and metallic Co species. When the CoFe0.08@NCS material is used as air-cathode catalyst of rechargeable liquid-state zinc-air battery (ZAB), the device shows a high peak power-density (157 mW m-2) and maintains a stable voltage gap over 150 h, outperforming those of the benchmark (Pt/C+RuO2)-based device. In particular, the as-fabricated solid-state flexible ZAB delivers a reliable compatibility under different bending conditions. Our work provides a promising strategy to develop metal/alloy-based electrocatalysts for the application in renewable energy conversion technologies.

Cyanide is the most widely used reagent in gold production processes. However, cyanide is highly toxic and poses safety hazards during transportation and use. Therefore, it is necessary to develop gold leaching reagents that can replace cyanide. This paper introduces a method for synthesizing a gold leaching reagent. Sodium cyanate is used as the main raw material, with sodium hydroxide and sodium ferrocyanide used as additives. The gold leaching reagent can be obtained under the conditions of a mass ratio of sodium cyanate, sodium hydroxide, and sodium ferrocyanide as 15:3:1, synthesis temperature of 600 ℃, and synthesis time of 1 hour. This reagent has a good recovery effect on gold concentrate and gold-containing electronic waste. The gold extraction rate of calcination-desulfurized gold concentrate can reach 87.56%. For the extraction experiments of three types of gold-containing electronic waste, the gold extraction rate can reach over 90% after 2 hours. Furthermore, the reagent exhibits good selectivity towards gold. Component analysis indicates that the effective component in the reagent could be sodium isocyanate.

Sinter is the core raw material for blast furnace. Flue pressure is an important state parameter which affects the quality of sinter. To predict the flue pressure and take targeted adjustment measures, this paper studied the flue pressure prediction and optimization based on the SHAP. Firstly, sintering process data was collected and processed. A flue pressure prediction model was constructed after comparing different feature selection methods and model algorithms by SHAP+ET. The prediction accuracy of model within the error range of ± 0.25 kPa was 92.63%. SHAP analysis was used to improve the interpretability of prediction model. We analyzed the influence of various sintering operation parameters on flue pressure, the relationship between numerical range of key operation parameters and flue pressure, the effect of operation parameter combinations on flue pressure and the prediction process of flue pressure prediction model on a single sample. A flue pressure optimization module was constructed and analyzed when the prediction met the judgment conditions. Operating parameter combination was pushed. During the verification process, the flue pressure was increased by 5.87%, achieving a good optimization effect.

To effectively activate peroxymonosulfate (PMS) for methylene blue (MB) degradation purposes, S and Co co-doped carbon catalysts were prepared by pyrolysing MOF-71 and thiourea mixtures at 800oC at the mass ratio of MOF-71 to thiourea of 1:0.1. The effects of two different mixing routes were identified on the MB degradation performance. Particularly, the catalyst obtained by the alcohol solvent evaporation (MOF-AEP) mixing route could degrade 95.60wt% MB (50 mg/L) within 4 minutes(k=0.78), which was faster than that originated from the direct grinding way (MOF-DGP, 80.97wt%, k=0.39). X-ray photoelectron spectroscopy (XPS) showed that the Co-S site of MOF-AEP (43.39%) was less than that of MOF-DGP(54.73%), and the proportion of C-S-C in MOF-AEP(13.56%) was higher than that of MOF-DGP (10.67%). Density functional theory (DFT) calculations showed that the adsorption energy of Co for PMS was -2.94 eV when sulfur was doped as C-S-C on the carbon skeleton, which was higher than that when sulfur was doped next to cobalt in the form of Co-S bond (-2.86 eV). It was thus speculated that the C-S-C sites might contribute more in activating PMS compared with Co-S. Furthermore, the degradation parameters including pH and MOF-AEP dosage were also investigated. Finally, radical quenching experiments and electron paramagnetic resonance (EPR) measurements revealed that 1O2 might be the primary catalytic species whereas the •O2− might be the secondary ones in degrading MB.

Iron oxide (Fe2O3) emerges as a highly attractive anode candidate among rapidly expanding energy storage market. Nonetheless, its considerable volume changes during cycling as an electrode material result in a vast reduced battery cycle life. We pioneer an approach for preparing high-performance Fe2O3 anode materials, by innovatively synthesizing a triple-layer yolkshell Fe2O3 uniformly coated with a conductive polypyrrole layer (Fe2O3@Ppy-TLY). The uniform polypyrrole coating enhances the material's electrical conductivity and maintains structure stability through charge/discharge process. In the uses as lithium-ion battery electrodes, Fe2O3@Ppy-TLY demonstrates high reversible specific capacity (maintaining a discharge capacity of 1375.11 mAh·g-1 after 500 cycles at 1 C), exceptional cycling stability (retaining the steady charge-discharge performance at 544.33 mAh·g-1 after 6000 ultrafast charge/discharge cycles at a 10 C current density), and outstanding high current charge-discharge performance (retaining a reversible capacity of 156.75 mAh·g-1 after 10000 cycles at 15 C), thereby exhibiting superior lithium storage performance. This study introduces innovative advancements for Fe2O3 anode design, aiming to enhance its performance in energy storage fields.

Hexagonal MnMX-based (M = Co or Ni, X = Si or Ge) alloys exhibit giant reversible barocaloric effects. However, giant volume expansion would result in the as-cast MnMX ingots fragment into powders, and inevitably bring the deterioration of mechanical properties and formability. Grain fragmentation can bring degradation of structural transformation entropy change during cyclic application and removal of pressure. In this paper, giant reversible barocaloric effects with high thermal cycle stability can be achieved in the epoxy bonded (MnCoGe)0.96(CuCoSn)0.04 composite. Giant reversible isothermal entropy change of 43 J∙kg-1K-1 along with reversible adiabatic temperature change up to 15.6 K can be obtained within a wide temperature span of 30 K at 3.6 kbar, which is mainly attributed to the integration of large the the change in the transition temperature driven by pressure (dT/dp) of −10.1 K∙kbar-1 and suitable thermal hysteresis of 11 K. Further, the variation of reversible adiabatic temperature change against the applied hydrostatic pressure reaches up to 4.3 K∙kbar-1, which is at the highest level among the other reported giant barocaloric compounds. More importantly, after 60 thermal cycles, the composite does not break and the calorimetric curves coincide well, performing good thermal cycle stability.

Safe emplacement of high-level nuclear waste (HLNW) arising from the utilization of nuclear power is a frequently encountered and considerably challenging issue. The widely accepted and feasible approach for the permanent disposal of HLNW involves housing it in a corrosion-resistant container and subsequently burying it deep in a geologic repository. The focus lies on ensuring the durability and integrity of the container in this process. This paper introduces various techniques and strategies employed in controlling the corrosion of used fuel containers (UFCs) using copper (Cu) as a corrosion barrier in the context of deep geological disposal. Overall, these corrosion prevention techniques and methods have been effectively implemented and employed to successfully mitigate the corrosion challenges encountered during the permanent disposal of Cu containers (e.g., corrosion mechanisms, corrosion parameters) in deep geologic repositories. The primary objective of this review is to provide an extensive examination of the alteration in the corrosion environment encountered by the UFCs when subjected to deep geologic repository conditions and focusing on addressing the potential corrosion scenarios.

Undoubtedly, the enormous progress observed in recent years in the Ni-rich layered cathode materials has been crucial in terms of pushing boundaries of the Li-ion battery (LIB) technology. The achieved improvements in the energy density, cyclability, charging speed, reduced costs, as well as safety and stability, already contribute to the wider adoption of LIBs, which extends nowadays beyond mobile electronics, power tools, and electric vehicles, to the new range of applications, including grid storage solutions. With numerous published papers and broad reviews already available on the subject of Ni-rich oxides, this review focuses more on the most recent progress and new ideas presented in the literature references. The covered topics include doping and composition optimization, advanced coating, concentration gradient and single crystal materials, as well as innovations concerning new electrolytes and their modification, with the application of Ni-rich cathodes in solid-state batteries also discussed. Related cathode materials are briefly mentioned, with the high-entropy approach and zero-strain concept presented as well. A critical overview of the still unresolved issues is given, with perspectives on the further directions of studies and the expected gains provided.

The accurate prediction of molten steel temperature in the ladle furnace (LF) refining process has an important influence on the quality of molten steel and the control of steelmaking cost.. Extensive research has been conducted on establishing models to predict molten steel temperature. However, most researchers focus solely on improving the accuracy of the model, neglecting its explainability. This study aimed to develop a high-precision and explainable model and improve reliability and transparency of model. The eXtreme Gradient Boosting (XGBoost) and Light Gradient Boosting Machine (LGBM) were utilized, along with Bayesian optimization and Grey Wolf Optimization (GWO), to establish the prediction model. Different performance evaluation metrics and graphical representations were used to compare the optimal XGBoost and LGBM models obtained through different hyperparameter optimization methods with the other models. The findings indicated that the GWO-LGBM model outperformed other methods in predicting molten steel temperature, with a high prediction accuracy of 89.35% within the error range of ±5℃. Based on the tree structure visualization and SHapley Additive exPlanations analysis, the model's learning/decision process was revealed and the degree of influence of different variables on the molten steel temperature was clarified, which enhanced the explainability of the optimal GWO-LGBM model and provided reliable support for prediction results.

Flotation is the most common approach to obtaining concentrate through the selective adsorption of collectors on target minerals. In the hydrometallurgy of concentrate, adsorbed collectors can damage ion-exchange resin and increase the chemical oxygen demand (COD) value of wastewater. Thus, adsorbed collectors must be desorbed before metallurgy and reused in flotation. Lead nitrate and benzohydroxamic acid (Pb-BHA) complex collector is a common collector in scheelite flotation. In this study, different physical (stirring or ultrasonic vibration) and chemical (acid or alkali) methods for facilitating the desorption of Pb-BHA collector from scheelite concentrate were explored. Single-mineral desorption tests showed that under the condition of pulp pH 13 and ultrasonic treatment for 15 min, the highest desorption rates of Pb and BHA adsorbed on the scheelite concentrate surfaces were 90.48% and 63.75%, respectively. Real-ore flotation tests revealed that the reuse of desorbed Pb-BHA collector reduced the collector cost by 30% for BHA and 25% for Pb. The cavitation effect of ultrasonic waves effectively reduced the interaction intensity between Pb-BHA collector and scheelite surfaces. Meanwhile, solution chemistry calculations revealed that the strong alkali environment broke the chemical bonds between Pb and BHA. This method combining desorption and reuse can reduce collector costs for beneficiation plants and provide clean scheelite concentrate for smelting plants.

In the realm of proton exchange membrane fuel cells (PEMFCs), the bipolar plates (BPs) are indispensable and serve pivotal roles in distributing reactant gases, collecting current, facilitating product water removal, and cooling the stack. Metal BPs, characterized by outstanding manufacturability, cost-effectiveness, higher power density, and mechanical strength, are emerging as viable alternatives to traditional graphite BPs. The foremost challenge for metal BPs lies in enhancing their corrosion resistance and conductivity under acidic conditions, necessitating the application of various coatings on their surfaces to ensure superior performance. This review summarizes and compares recent advancements in the research of eight distinct types of coatings for BPs in PEMFCs, including noble metal, carbide, nitride, and a-C + metal/metal compound composite coatings. The various challenges encountered in the manufacturing and future application of these coatings are also delineated.

Additive manufacturing enables rapid fabrication of complex components through layer-by-layer formation. At present, there is a paucity of addressing the effects on cellular microstructures and mechanical properties during the process of laser powder bed fusion (LPBF). Therefore, this study systematically investigated the influence of cellular microstructure and mechanical properties response of maraging steel by LPBF. Increasing the laser scanning speed does not lead to a noticeable change in the phase fraction, but it reduces the average size of the cellular structure from 0.6 μm to 0.35 μm. The scanning speed is 400 mm/s and 1000 mm/s are both have adverse effects on performance, resulting in inadequate fusion and keyhole defects, respectively. The optimal scanning speed for fabricating samples is determined to be 800 mm/s, which exhibits the highest room temperature tensile strength and elongation. The ultimate tensile strength measures at 1088.3±2.0 MPa, with an elongation of 16.76±0.2%. The mechanism of the evolution of surface morphology, defects, and energy input were clarified, the relationship between cellular structure size and mechanical property was also established.

Understanding the mechanical properties of the lithologies is crucial to accurately determine the horizontal stress magnitude. To investigate the correlation between the rock mass properties and maximum horizontal stress, the 3D stress tensors at 89 measuring points determined using an improved overcoring technique in nine mines in China were adopted, a newly defined characteristic parameter ERP was proposed as an indicator for evaluating the structural properties of rock masses, and a fuzzy relation matrix was established using the information distribution method. The results indicate that both the vertical stress and horizontal stress exhibit a good linear growth relationship with depth. There is no remarkable correlation between the elastic modulus and elastic modulus and depth, and the distribution of data points is scattered and messy. Moreover, there is no obvious relationship between the RQD and depth. The maximum horizontal stress σH is a function of rock properties, showing a certain linear relationship with the ERP at the same depth. In addition, the overall change trend of σH determined by the established fuzzy identification method increases with the increase of ERP, and the fuzzy identification method also demonstrates a relatively detailed local relationship between σH and ERP, and the predicted curve rises in a fluctuating way, which is in accord well with the measured stress data.

At present, the emerging solid-phase friction-based additive manufacturing technology, including friction rolling additive manufacturing (FRAM), can only manufacture simple single-pass components. In this study, multi-layer multi-pass FRAM-deposited aluminum alloy samples are successfully prepared using a non-shoulder tool head. The material flow behavior and microstructure of the overlapped zone between adjacent layers and passes during multi-layer multi-pass FRAM deposition are studied using the hybrid 6061 and 5052 aluminum alloys. The results showed that a mechanical interlocking structure was formed between the adjacent layers and adjacent passes in the overlapped center area. Repeated friction and rolling of the tool head led to different degrees of lateral flow and plastic deformation of the materials in the overlapped zone, which made the recrystallization degree in the left and right edge zones of the overlapped zone the highest, followed by the overlapped center zone and the non-overlapped zone. The tensile strength of the overlapped zone exceeded 90% of that of the single-pass deposition sample. It is proved that although there are uneven grooves on the surface of the overlapping area during multi-layer and multi-pass deposition, they can be filled by the flow of materials during the deposition of the next layer, thus ensuring the dense microstructure and excellent mechanical properties of the overlapping area. The multi-layer multi-pass FRAM deposition overcomes the limitation of deposition width and lays the foundation for the future deposition of large-scale high-performance components.

Fe-Ga alloys are potential for the new-generation magnetostrictive applications in sensors, transducers, and actuators due to the combination of large magnetostriction and good structural properties.<001>-oriented Fe-Ga sheets with large magnetostriction are required for improving the conversion efficiency under the ultra-high frequency magnetic field. Trace Tb element doping can simultaneously improve the magnetostriction and ductility of Fe-Ga alloy. However, the impact of trace Tb doping on the microstructure and magnetostriction of Fe-Ga thin sheets is an open question. In this paper, the effects of trace Tb addition on the secondary recrystallization and magnetostriction of Fe-Ga thin sheets are systematically studied by comparing the characteristics evolution of precipitation, texture, and nanoinclusions. The results indicates that trace Tb addition accelerates the secondary recrystallization of Goss grains due to the combined action of the bimodal size distributed precipitates, smaller grains, and more HEGBs in primary recrystallization. After quenching at 900 °C, the magnetostriction value in 0.07%Tb-doped Fe81Ga19 thin sheets increases 30% than that of Fe81Ga19 thin sheets. The increase of magnetostriction is attributed to the decrease in the number of Tb-rich precipitates and the higher density of the nanometer-sized modified-D03 inclusions induced by the dissolving of trace Tb elements after quenching. These results demonstrate a simple and efficient approach for preparing Fe-Ga thin sheets with excellent magnetostriction by a combination of trace RE element addition and conventional rolling method.

This study primarily investigates the rock fracture mechanism of bottom cushion layer blasting and explores the effects of the bottom cushion layer on rock fragmentation. It involves analysis of the evolution patterns of blasting stress, characteristics of crack distribution, and rock fracture features in the specimens. First, blasting model experiments are carried out using the dynamic caustics principle to investigate the influence of bottom cushion layers and initiation methods on the integrity of the bottom rock mass. The experimental results indicate that the combined use of bottom cushion layers and inverse initiation effectively protects the integrity of the bottom rock mass. Subsequently, the process of stress wave propagation and dynamic crack propagation in rocks was simulated using the Continuous-Discontinuous Element Method (CDEM) and the Landau explosion source model, with varying thicknesses of bottom cushion layers. The numerical simulation results indicate that with increasing cushion thickness, the absorption of energy generated by the explosion becomes more pronounced, resulting in fewer cracks in the bottom rock mass. This illustrates the positive role of the cushion layer in protecting the integrity of the bottom rock mass.

Interface modulation is an important pathway for high-efficiency electromagnetic wave absorption. Herein, tailored interfaces between Fe3O4 particles and the hexagonal-YFeO3 (h-YFeO3) framework were constructed via facile self-assembly, resulting in enhanced dielectric and magnetic loss synergy via interfacial electron rearrangement at the heterojunction. Experimental results and density function theory (DFT) simulations demonstrate a transition in electrical properties from a half-metallic monophase to metallic Fe3O4/h-YFeO3 composites, emphasizing the advantageous effect of hetero-interface formation. The transformation of electron behavior demonstrates a redistribution of electrons at the Fe3O4−h-YFeO3 heterojunction, leading to a localized electron accumulation around the Y-O-Fe band bridge, consequently yielding enhanced polarization. A minimum reflection loss of -34.0 dB can be achieved at 12.0 GHz at 2.0 mm thickness with an effective bandwidth of 3.3 GHz due to the abundant interfaces, enhanced polarization, and rational impedance. Thus, the synergistic effects endow the Fe3O4/h-YFeO3 composites with high-performance and tunable functional properties for efficient electromagnetic absorption.

The binder phase performs critically on the comprehensive properties of cemented carbides, especially the hardness and fracture toughness relationship. There are strong motivations in both research community and industry for developing alternative binders to Co in cemented carbide system, due to the reasons such as price instability, property degeneration and toxicity. Herein, six kinds of high entropy alloys (HEA) including CoCrFeNiMn, CoCrFeMnAl, CoCrFeNiAl, CoCrNiMnAl, CoFeNiMnAl and CrFeNiMnAl were employed as the alternative binder for the preparation of WC-HEA cemented carbides through mechanical alloying and two-step spark plasma sintering. The impacts of HEA on the microstructures, mechanical properties and thermal conductivity of WC-HEA hardmetals were determined and discussed. WC-HEA hardmetals exhibited both superior hardness and fracture toughness to WC-Metal or WC-Intermetallic cemented carbides, indicating that HEA alloys were not only harder but also tougher in comparison with traditional metal or intermetallic binders. The HEA bonded hardmetals yielded thermal conductivities much lower than that of traditional WC-Co cemented carbide. The excellent HV-KIC relationship of WC-HEA facilitated the potential engineering structural application of cemented carbides.

The electrochemical behaviors of Sr on inert W electrode and reactive Zn/Al electrodes were systematically investigated in LiCl-KCl-SrCl2 molten salts at 773 K using various electrochemical methods. The chemical reaction potentials of Li and Sr on reactive Zn/Al electrodes were determined. It was found that Sr could be extracted by decreasing the activity of the deposited metal Sr on the reactive electrode, even though the standard reduction potential of Sr(II)/Sr was more negative than that of Li(I)/Li. The electrochemical extraction products of Sr on reactive Zn and Al electrodes were Zn13Sr and Al4Sr, with no co-deposition of Li observed. Based on density functional theory calculations, both Zn13Sr and Al4Sr were identified as stable intermetallic compounds of rich-Zn/Al phases. In LiCl-KCl molten salt containing 3wt% SrCl2, the coulombic efficiency of Sr in Zn electrode was approximately 54%. The depolarization values for Sr on Zn and Al electrodes were 0.864 V and 0.485 V, respectively, demonstrating a stronger chemical interaction between Zn and Sr. This work suggests that the use of reactive electrodes can facilitate the extraction of Sr accumulated in electrorefining molten salts, thereby enabling the purification and reuse of the salt and reducing the volume of nuclear waste.

Gels and conductive polymer composites including hydrogen bonds (HB) have developed into promising electromagnetic wave (EMW) absorption materials in response to different application scenarios. However, the relationship between conduction loss in EMW absorbing materials and charge transfer in HB remains to be explored. Herein, we construct a series of deep eutectic gels for fine-tuning the quantity of HB, by adjusting the ratio of choline chloride (ChCl) and ethylene glycol (EG). Due to the characteristics of deep eutectic gels, the impact of magnetic loss and polarization loss on EMW attenuation can be disregarded. The results indicate the quantity of HB increased first and then decreased with the introduction of EG, and HB-induced conductive loss exhibits similar patterns. At a ChCl and EG ratio of 2.4, G22-CE2.4 demonstrates the best EMW absorption performance (effective absorption bandwidth=8.50 GHz, thickness=2.54mm), which is attributable to the synergistic effects of excellent conductive loss and impedance matching generated by the appropriate number of HB. This work clarifies the role of HB in dielectric loss for the first time and offers a generic insight into the optimal design of supramolecular polymer absorbers.

Researchers have focused more on the depression mechanism of sulfite ions on copper activated sphalerite. The depression mechanism of sulfite ions on sphalerite and Pb2+ activated sphalerite in the flotation separation of galena from sphalerite still lacked in-depth understanding. Therefore, the depression mechanism of sulfite ions on sphalerite and Pb2+ activated sphalerite in the flotation separation of galena from sphalerite was further investigated by experiments and DFT calculations. Firstly, sulfite ions and oxygen were more likely to co-decompose xanthate treated by Zn2+ than xanthate treated by Pb2+, suggesting that the xanthate adsorbed on the surface of sphalerite was unstable. Secondly, sulfite ions were chelated with lead ions in solution to form PbSO3 and the hydrophilic PbSO3 was more easily adsorbed on sphalerite than galena. Thirdly, sphalerite was further inhibited by the product OH− in the oxidation process of sulfite ions, and OH− was more easily adsorbed on the surface of sphalerite in comparison with galena. However, sulfite ions hardly inhibited the flotation of galena and could promote the flotation of galena to some extent. Ultimately, sulfite ions could successfully achieve flotation separation of galena from sphalerite.

Carbon can change the phase components of low-density steels and influence the mechanical properties. In this study, a new method to control the carbon content and avoid the formation of δ-ferrite by decarburization treatment was proposed. The microstructural changes and mechanical characteristics with carbon content induced by decarburization were systematically examined. Crussard–Jaoul (C–J) analysis was employed to examine the work hardening characteristics during the tensile test. During decarburization by heat treatments, the carbon content within the austenite phase decreased, while Mn and Al were almost unchanged; this made the steel with full austenite transform into the austenite and ferrite dual phase. Meanwhile, (Ti, V) C carbides existed in both matrix phase and the mole fraction almost the same. In addition, the formation of other carbides restrained. Carbon loss induced a decrease in strength due to the weakening of the carbon solid solution. For the steel with the single austinite, the deformation mode of austenite was the dislocation planar glide, resulting in the formation of microbands. For the dual-phase steel, the deformation occurred by the dislocation planar glide of austenite first, with the increase in strain, the cross slip of ferrite took place, forming dislocation cells in ferrite. At the late stage of deformation, the work hardening of austinite increased rapidly, while that of ferrite increased slightly.

Copper, an essential metal for the energy transition, is primarily obtained from chalcopyrite through hydro and pyrometallurgical methods. The risk and harmfulness of this process represent the lack of safety for the environment and humans, so it is necessary to explore efficient and respectful hydrometallurgical methods. In this review article, emphasis is placed on current processes such as oxidative leaching, bioleaching, and pressure leaching that have shown efficiency in overcoming the complicated chalcopyrite network. The process of oxidative leaching epitomizes benign conditions within leaching media; nevertheless, the introduction of oxidizing agents confers extensive advantages. Bioleaching is a non-aggressive method that has shown a gradual increase in the contribution of copper and has been explored from primary and secondary sources. Pressure leaching, effective and selective for copper obtaining, becomes commercially more viable with increased research investments. This research also provides important data for advancing future research.

This work reveals the significant effects of cobalt (Co) on the microstructure and impact toughness in as-quenched high strength steels by both experimental characterizations and thermo-kinetic analyses. The results show that the Co-bearing steel exhibits finer blocks and a lower ductile-brittle transition temperature than the steel without Co. In addition, the Co-bearing steel shows higher transformation rates at the intermediate stage with bainite volume fraction ranging from around 0.1 to 0.6. The improved impact toughness of the Co-bearing steel results from the higher dense block boundaries dominated by V1/V2 variant pair. The addition of Co induces a larger transformation driving force and a lower bainite start (BS) temperature, which contributes to the refinement of blocks and the increase of V1/V2 variant pair. These findings would be instructive for the composition, microstructure design and properties optimization of high strength steels.

This study investigates the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy, YGdTbDyHo. Results indicate that the YGdTbDyHo alloy has a microstructure of equiaxed grains, with the alloy elements distributed homogeneously. Upon hydrogen absorption, the phase structure of the high-entropy alloy changes from the solid solution with HCP structure to the high-entropy hydride with FCC structure, without any secondary phase precipitated. The alloy demonstrates a maximum hydrogen storage capacity of 2.33 H/M at 723 K, with enthalpy change (ΔH) of -141.09 kJ·mol-1 and entropy change (ΔS) of -119.14 J·mol-1·K-1. The kinetic mechanism of hydrogen absorption is hydride nucleation and growth, with an apparent activation energy (Ea) of 20.90 kJ·mol-1. Without any activation, YGdTbDyHo alloy can absorb hydrogen quickly (180 s at 923 K) with nearly no incubation period observed. The reason for 2.33 H/M is suggested that the hydrogen atoms occupy both the tetrahedral and octahedral interstice. These results demonstrate the potential application of High-Entropy Alloys (HEAs) as a high-capacity hydrogen storage material with a large H/M ratio, which can be used in the deuterium storage field.

The densely-distributed coherent nanoparticles (DCN) in steel matrix can enhance work-hardening ability and ductility of steel simultaneously. All the routes to this end can be generally classified into Liquid-Solid route (LSR) and Solid-Solid route (SSR). However, the formation of DCN structure in steel requires a long-time process and complex steps. So far, obtaining steel with coherent particle enhancement in a short time remains bottleneck, meanwhile some necessary steps are unavoidable. Here we show a high efficiency liquid-phase refining (LPR) process reinforced by dynamic magnetic field (DMF). The Ti-Y-Mn-O (TYMO) particles are around 3.53 ± 1.21 nm in average size, and can be obtained in just around 180 sec. These small nanoparticles are coherent with matrix, implying no accumulated dislocations between particle and steel matrix. Our findings have a potential application towards improving material machining capacity, creep resistance and radiation resistance.

Carbon materials are widely recognized as highly promising electrode materials for various energy storage system applications. Coal tar residues (CTR), as a type of carbon-rich solid waste with high value-added utilization, are crucially important for the development of a more sustainable world. In this study, we employed a straightforward direct carbonization method within the temperature range of 700-1000 °C to convert the worthless solid waste CTR into economically valuable carbon materials as anodes for potassium-ion batteries (PIBs). The effect of carbonization temperature on the microstructure and the potassium ions storage properties of CTR-derived carbons (CTRCs) were systematically explored by structural and morphological characterization, alongside electrochemical performances assessment. Based on the co-regulation between the turbine layers, crystal structure, pore structure, functional groups, and electrical conductivity of CTR-derived carbon carbonized at 900 °C (CTRC-900H), the electrode material with high reversible capacity of 265.6 mA·h g−1 at 50 mA·g−1, a desirable cycling stability with 93.8% capacity retention even after 100 cycles, and the remarkable rate performance for PIBs were obtained. Furthermore, cyclic voltammetry (CV) at different scan rates and galvanostatic intermittent titration technique (GITT) have been employed to explore the potassium ions storage mechanism and electrochemical kinetics of CTRCs. Results indicate that the electrode behavior is predominantly governed by surface-induced capacitive processes, particularly under high current densities, with the potassium storage mechanism characterized by an "adsorption-weak intercalation" mechanism. This work highlights the potential of CTR-based carbon as a promising electrode material category suitable for high-performance PIBs electrodes, while also provides valuable insights into the new avenues for the high value-added utilization of CTR.

To enhance the microbiologically influenced corrosion (MIC) resistance of FeCoNiCrMn high entropy alloy (HEAs), a series of Fe_xCu_(1-x)CoNiCrMn (x = 1, 0.75, 0.5, and 0.25) HEAs were prepared. Microstructural characteristics, corrosion behavior (morphology observation and electrochemical properties), and antimicrobial performance of Fe_xCu_(1-x)CoNiCrMn HEAs were evaluated in a medium inoculated with typical corrosive microorganism Pseudomonas aeruginosa. The aim was to identify copper-containing FeCoNiCrMn HEAs that balance corrosion resistance and antimicrobial properties. Results revealed that all Fe_xCu_(1-x)CoNiCrMn (x = 1, 0.75, 0.5, and 0.25) HEAs exhibited an FCC phase, with significant grain refinement observed in Fe_0.75Cu_0.25CoNiCrMn HEA. Electrochemical tests indicated that Fe_0.75Cu_0.25CoNiCrMn HEA demonstrated lower corrosion current density (i_corr) and pitting potential (E_pit) compared to other Fe_xCu_(1-x)CoNiCrMn HEAs in P. aeruginosa-inoculated medium, exhibiting superior resistance to MIC. Anti-microbial tests showed that after 14 days of immersion, Fe_0.75Cu_0.25CoNiCrMn achieved an antibacterial rate of 89.5%, effectively inhibiting the adhesion and biofilm formation of P. aeruginosa, thereby achieving resistance to MIC.

The local structure and thermophysical behavior of Mg-La liquid alloys were in-depth understood using deep potential molecular dynamic (DPMD) simulation driven via machine learning to promote the development of Mg-La alloys. The robustness of the trained DP model was thoroughly evaluated through several aspects, including root-mean-square errors (RMSEs), energy and force data, and structural information comparison results, the results indicating the carefully trained DP model is reliable. The component and temperature dependence of the local structure in the Mg-La liquid alloy was analyzed. The effect of Mg content in the system on the first coordination shell of the atomic pairs is the same as that of temperature. The pre-peak demonstrated in the structure factor indicates the presence of a medium-range ordered structure in the Mg-La liquid alloy, which is particularly pronounced in the 80% Mg system and disappears at elevated temperatures. The density, self-diffusion coefficient, and shear viscosity for the Mg-La liquid alloy were predicted via DPMD simulation, and the evolution patterns with Mg content and temperature were subsequently discussed, and a database was established accordingly. Finally, the mixing enthalpy and elemental activity of the Mg-La liquid alloy at 1200 K were reliably evaluated, which provides new guidance for related studies.

A superhydrophobic and corrosion-resistant LDH-W/PFDTMS composite coating was prepared on the surface of Mg alloy. The LDH-W/PFDTMS composite comprised of a tungstate-intercalated (LDH-W) underlayer that was grown at a low temperature (versus hydrothermal reaction condition) under atmospheric pressure and a polysiloxane outer layer obtained in a solution containing perfluorodecyltrimethoxysilane (PFDTMS) by a simple immersion method. The successful intercalation of tungstate into the LDH phase and the following formation of the polysiloxane layer were confirmed by the X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of the LDH-W film before and after PFDTMS modification was evaluated by electrochemical impedance spectroscopy (EIS), Tafel curves, and immersion experiments. Compared with the pure LDH-W film, the LDH-W/PFDTMS coating exhibited significantly enhanced corrosion protection for Mg alloy, with no apparent signs of corrosion after exposure to a 3.5wt% NaCl solution for 15 days. The static contact angle and water repellency tests of the LDH-W/PFDTMS coating demonstrated the superior superhydrophobicity and self-cleaning ability for water and several common beverages in daily life. These results guide the preparation of superhydrophobic and corrosion-resistant LDH-based composite coatings on Mg alloy surfaces under relatively mild reaction conditions.

The rich resources and unique environment of moon position it as the prime candidate for human development and the utilization of extraterrestrial resources. Oxygen plays a vital role in supporting human life on the moon, with lunar regolith serving as a highly oxygen-rich polymetallic oxide that can be processed using existing metallurgical techniques to extract oxygen and metals. Furthermore, the ample reserves of water ice on the moon offer an additional avenue for oxygen production. This paper offers a detailed overview of the leading technologies poised to achieve in-situ oxygen production on the moon, drawing from an analysis of lunar resources and environmental conditions. It delves into the principles, processes, advantages, and drawbacks of water ice electrolysis, two-step oxygen production from lunar regolith, and one-step oxygen production from lunar regolith. The two-step methods involve hydrogen reduction, carbothermal reduction, and hydrometallurgy, while the one-step methods encompass fluorination/chlorination, high-temperature decomposition, molten salt electrolysis, and molten regolith electrolysis (MOE). Following a thorough comparison considering raw materials, equipment, technology, and economic viability, MOE emerges as the most promising approach for future lunar in-situ oxygen production. Considering the high-temperature corrosion characteristics of molten lunar regolith, as well as the environmental characteristics of low gravity on the moon, the development of inexpensive and stable inert anodes and the development of electrolysis devices that can easily collect oxygen are considered key breakthroughs in promoting MOE technology on the moon. This review holds substantial theoretical importance in enhancing our understanding of lunar in-situ oxygen production technology and the forthcoming lunar exploration initiatives.

The photocatalytic activities of catalysts depend on energy harvesting ability and the separation/transport of photogenerated carriers. The surface plasmon resonance (SPR) of noble metal nanoparticles (e.g., Cu, Au, Pd etc.) can be adjusted in the entire visible region via varying the nanocomponents of the material to attain enhanced light absorption capacity of graphitic carbon nitride (g-C3N4) based composites. With the SPR of noble metals been able to enhance the local electromagnetic field and improve the interband transition as well as the resonant energy transfer occurred from the plasmonic dipoles to electron-hole pairs via near-field electromagnetic interactions, noble metals have been quite popular nanocomponents materials in the case of g-C3N4 modification for the applications of CO2 photoreduction and water splitting. Herein, recent key advances in noble metals (either in single atom, cluster, or nanoparticle forms) and inorganic/organic nanocomponents incorporated g-C3N4 nanosheets based composite photocatalysts with improved photoinduced charge mobility are systematically discussed, particularly, the significant applications of these photocatalysts in CO2 photo-conversion and H2 production. Issues related to the different types of multi-nanocomponent heterostructures (involving Schottky junctions, Z-/S-scheme heterostructures, composed of noble metals and additional semiconductor nanocomponents) as well as the adjustment of dimensionality of the heterostructures (by incorporating noble metal nanoplates on g-C3N4 forming 2D/2D heterostructures) are also discussed. The current prospects and possible challenges of the noble metal (e.g., Au, Pt, Pd, and Cu) incorporated g-C3N4 composite photocatalysts, particularly in water splitting, CO2 reduction, pollution degradation, and chemical conversion applications are summarized.

Microstructure, texture and mechanical properties of the extruded Mg-2.49Nd-1.82Gd-0.2Zn-0.2Zr alloy were investigated at different extrusion temperatures (260 ℃ and 320 ℃), extrusion ratios (10:1, 15:1 and 30:1) and extrusion speeds (3 mm/s and 6 mm/s), respectively. The experimental results exhibited that the grain sizes after extrusion were much finer than that of the homogenized alloy, and the second phase showed streamline distribution along the extrusion direction (ED). With extrusion temperature increased from 260 ℃ to 320 ℃, the microstructure, texture and mechanical properties of alloys changed slightly. The DRX degree and grain sizes enhanced as the extrusion ratio increased from 10:1 to 15:1 and 30:1, and the strength gradually decreased but elongation (EL) increased. With the extrusion speed increased from 3 mm/s to 6 mm/s, the grain sizes and DRX degree increased significantly, and both samples presented the typical<21 1="">-<112 3="">rare-earth (RE) textures. The alloy extruded at 260 ℃ with extrusion ratio of 10:1, extrusion speed of 3 mm/s showed the best comprehensive properties with tensile yield strength (TYS) of 213 MPa and EL of 30.6%. After quantitatively analyzing the contribution of strengthening mechanisms, it was found that the grain boundary strengthening and dislocation strengthening played major roles among strengthening contributions. These results provide some guidelines for enlarging the industrial application of extruded Mg-RE alloy.

BiVO4 porous spheres modified by ZnO were designed and synthesized using a facile two-step method. The resulting ZnO/BiVO4 composite catalysts have shown remarkable efficiency as piezoelectric catalysts for degrading Rhodamine B (RhB) under mechanical vibrations, they exhibit superior activity compared to pure ZnO. The 40% ZnO/BiVO4 heterojunction composite displayed the highest activity, along with good stability and recyclability. The enhanced piezoelectric catalytic activity can be attributed to the formation of an Ⅰ-scheme heterojunction structure, which can effectively inhibit the electron-hole recombination. Furthermore, hole (h+) and superoxide radical (·O2-) are proved to be the primary active species. Therefore, ZnO/BiVO4 stands as an efficient and stable piezoelectric catalyst with a broad potential application in the field of environmental water pollution treatment.

As a separation and purification technology, solvent extraction is crucial in the field of critical metals metallurgy. At present, organic solvents mostly utilized in solvent extraction have the disadvantages of high volatility, high toxicity, and flammability, causing a spectrum of hazards for human health and environmental protection. Neoteric solvents are being recognized as preferable alternatives to these harmful organic solvents. In the past two decades, several neoteric solvents have been proposed involving ionic liquids (ILs) and deep eutectic solvents (DESs). DESs have gradually become the focus of green solvents owing to several advantages including low toxicity, degradability, and low cost. In this critical review, a systematic description on their classification, formation mechanisms, preparation methods, characterization technologies, and special physicochemical properties based on the most recent advancements in research. Afterwards, the major separation and purification applications of DESs in critical metals metallurgy and other fields were comprehensively summarized. Finally, the future opportunities and challenges about DESs were prospected in the current area of research. In conclusion, this review provides valuable insights for improving our overall understanding of deep eutectic solvents, and it has important significance for expanding separation and purification applications in critical metals metallurgy.

To effectively investigate the impact of composite relationship of Mxene (Ti3C2Tx) and nano-FeCoNi magnetic particles on the electromagnetic absorption properties of composite, three sets of Mxene (Ti3C2Tx)@nano-FeCoNi composite materials with Mxene content of 15mg, 45mg, and 90mg were prepared with in-situ liquid phase deposition. The microstructure, static magnetic properties, and electromagnetic absorption performance of these composites were studied. The results indicate that the Mxene@nano-FeCoNi composite material was primarily composed of face-centered cubic crystal structure particles and Mxene, with spherical FeCoNi particles uniformly distributed on the surface of the multilayered Mxene. The average particle size of the alloy particles was approximately 100 nanometers, exhibiting good dispersion without noticeable particle aggregation. With the increase of Mxene content, the specific saturation magnetic and coercivity of the composite initially decrease and then increase, displaying typical soft magnetic properties. In comparison with FeCoNi magnetic alloy particles, the addition of Mxene causes an increasing trend in the real and imaginary parts of the dielectric constant of the composite, while the real and imaginary parts of the magnetic permeability exhibit a decreasing trend. The inclusion of Mxene enhances the dielectric loss but reduces the magnetic loss. Additionally, the dielectric loss and magnetic loss performance of the composite material do not show a linear function relationship with the addition of Mxene. Both the FeCoNi magnetic alloy particles and the Mxene@FeCoNi composite material exhibit polarization relaxation loss, and it was found that eddy current loss was not the main mechanism of magnetic loss. The material attenuation constant increases with the addition of Mxene, while the impedance matching decreases. Moreover, the maximum reflection loss increases and the maximum effective absorption bandwidth decreases with the addition of Mxene. When the Mxene addition was 90mg, the composite material exhibits a maximum reflection loss |RLmax| of 46.9dB with sample thickness of 1.1mm, and a maximum effective absorption bandwidth of 3.60GHz with sample thickness of 1.0mm. The effective absorption bandwidth of the composite material shows a decreasing trend with the corresponding sample thickness as the Mxene addition increases, reducing by 50% from 1.5mm without Mxene addition to 1mm with 90mg Mxene addition. These findings provide valuable insights for optimizing absorption coating thickness and weight.

Exploring high-efficient and broadband microwave absorption (MA) materials with corrosion resistance and low cost is urgently needed for widely practical applications. Herein, the natural porous attapulgite (ATP) nanorods embedded with TiO2 and polyaniline (PANI) nanoparticles are synthesized via heterogeneous precipitation and in-situ polymerization. The obtained PANI-TiO2-ATP one-dimensional nanostructures can intertwine into three-dimensional conductive network, which is favored for the energy dissipation. The minimum reflection loss (RLmin) of PANI-TiO2-ATP coating (20wt%) reaches -49.36 dB at 9.53 GHz，and the effective absorption bandwidth (EAB) can reach 6.53 GHz with a thickness of 2.1 mm. The excellent microwave absorption properties are attributed to the interfacial polarization, multiple losses mechanisms and good impedance matching induced by the synergistic effect of PANI-TiO2 nanoparticle shells and ATP nanorods. In addition, salt spray and Tafel polarization curve tests reveal that the PANI-TiO2-ATP coating shows outstanding corrosion resistance performance. This study provides a low-cost and high efficiency strategy to construct one dimensional nano-networks composites for microwave absorption and corrosion resistance applications using natural porous ATP nanorods as a carrier.

Influence of Nb-V microalloying on hot deformation behavior and microstructures of medium Mn steel (MMS) was investigated by uniaxial hot compression tests. By establishing the constitutive equations for simulating the measured flow curves, we successfully constructed deformation activation energy (Q) maps and processing maps for identifying the region of flow instability. We may conclude the following consequences as the Nb-V alloying of MMS: (i) The critical strain is increased and the increment diminishes with the increasing deformation temperature, suggesting that NbC precipitates could retard dynamic recrystallization (DRX) in MMS more than the solute Nb; (ii) The deformation activation energy of MMS is significantly increased and even more than high Mn steels, suggesting that it retards DRX more than high content of Mn; (iii) The hot workability of MMS is improved by narrowing the hot processing window for the unstable flow stress, in which the mixed presence of both fine recrystallized and coarse unrecrystallized grains has been confirmed.

Currently, the Al2O3 content in the high-alumina slag systems within blast furnaces is generally limited to 16-18.5wt%, making it challenging to overcome this limitation. Unlike most studies that concentrated on managing the MgO/Al2O3 ratio or basicity, this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO‐MgO‐Al2O3‐SiO2 slag system, providing theoretical guidance and data to facilitate the application of high-alumina ores. The results revealed that the viscosity first decreased and then increased with higher MgO substitution, reaching a minimum at 15mol% MgO concentration. FTIR results found that the depths of the troughs representing [SiO4] tetrahedra, [AlO4] tetrahedra, and Si-O-Al bending became progressively deeper with increased MgO substitution. Deconvolution of the Raman spectra showed that the average number of bridging oxygens per Si atom and the Q3/Q2 ratio increased from 2.30 and 1.02 to 2.52 and 2.14, respectively, indicating a progressive polymerization of the silicate structure. XPS results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration, whereas bridging oxygen and free oxygen contents increased. Structural analysis demonstrated a gradual increase in the degree of polymerization of the tetrahedral structure with the increase in MgO substitution. However, bond strength is another important factor affecting the slag viscosity. The occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the [SiO4] and [AlO4] tetrahedral structures by CaO and MgO.

Using SiC nanowires (SiC_NWs) as the substrate, the reflux-annealing method and electro-deposition-carbonization technique were sequentially applied to integrate SiC nanowires with magnetic Fe₃O₄ nanoparticles and amorphous nitrogen-doped carbon (NC), resulting in the fabrication of SiC_NWs@Fe₃O₄@NC nanocomposite. Comprehensive testing and characterization of this product have provided valuable insights into the impact of structural and composition changes on its electromagnetic wave absorption performances. The optimized SiC_NWs@Fe₃O₄@NC nanocomposite, containing a 30 wt% filler content and a matching thickness of 2.03 mm, demonstrates exceptional performance with a minimum reflection loss (RL_min) of -53.69 dB at 11.04 GHz and an effective absorption bandwidth (EAB) of 4.4 GHz. This investigation thoroughly elucidates the synergistic effects of the enhanced nanocomposites on electromagnetic wave absorption, drawing on theories of multiple scattering, polarization relaxation, hysteresis loss and eddy current loss. Furthermore, a multi-component electromagnetic wave attenuation model has been established, providing valuable insight for designing novel absorbing materials and enhancing their absorption performances. This research demonstrates the significant potential of the SiC_NWs@Fe₃O₄@NC nanocomposite as a highly efficient electromagnetic wave absorbing material, with potential applications in various fields, such as stealth technology and microwave absorption.

Developing high ionic conducting electrolytes is crucial for applying proton-conducting fuel cell (PCFCs) practically. The current study investigates the effect of alumina on the structural, morphological, electrical and electrochemical properties of CeO2. Lattice oxygen vacancies are induced in CeO2 by a general doping concept that enables fast ionic conduction at low-temperature ranges (300-500 ℃)  for PCFCs. Rietveld refinement of the XRD patterns established the pure cubic fluorite structure of Al-doped CeO2 (ADC) samples and confirmed Al ions integration in the CeO2 lattice. The electronic structure of the alumina-doped ceria of the materials (10ADC, 20ADC, and 30ADC) has been investigated. As a result, it was found that the best composition of 30ADC-based electrolytes induced maximum lattice oxygen vacancies. The corresponding PCFC exhibited a maximum power output of 923 mW/cm2 at 500 ℃. Moreover, the investigation proves the proton-conducting ability of alumina-doped ceria-based fuel cells by using an oxide ion-blocking layer.

BiFeO3 (BFO) has received much attention as a lead-free ferroelectric film due to its large theoretical remnant polarization, but it suffers from a large leakage current, resulting in poor ferroelectric properties. Herein, a series of BFO-based thin films were deposited on fluorine-doped tin oxide (FTO) substrates by the sol-gel method, and the effects of the mixed substitution of the elements Co, Cu, Mn (B-site) and Sm, Eu, La (A-site) on the crystal structure, ferroelectricity, and leakage current of the BFO-based thin films were investigated. It is confirmed that the substitution of individual elements in the BFO-based films caused lattice distortion by X-ray diffraction. Sm and Eu substitutions make the lattice distorted to a pseudo-cubic structure, while La is biased toward pseudo-tetragonal. Piezoelectric force microscopy confirms that the prepared films can achieve reversible switching of ferroelectric domains by nearly 180°. The ferroelectric hysteresis loops shows that the order for the polarization contribution is: Cu>Co>Mn (B-site), Sm>La>Eu (A-site). And the current density voltage curves indicate that the order for leakage contribution is: Mn<Cu<Co (B-site), La<Eu<Sm (A-site). The scanning electron microscopy shows that the introduction of Cu element favors the formation of dense grains, and the grain size distribution statistics prove that La element favors the reduction of grain size, which leads to the increase of grain boundaries and the reduction of leakage. Finally, we prepared Bi0.985Sm0.045La0.03Fe0.96Co0.02Cu0.02O3 (SmLa-CoCu) thin film with a qualitative leap in the remnant polarization from 25.5 (Bi0.985Sm0.075FO3) to 98.8 µC/cm2 (SmLa-CoCu) through the synergistic action of Sm, La, Co, and Cu elements. And the leakage current is also significantly reduced from 160 to 8.4 mA/cm2 at a field strength of 150 kV/cm. Thus, the present study focuses on the notion of enhancing ferroelectricity and decreasing leakage current, based on chemical engineering increasing entropy strategy, which provides a promising path for the advancement of ferroelectric devices.

Pt-based nanocatalysts have remarkable prospect for industry. However, the low loading of Pt with excellent performance for efficient and stable nanocatalysts still remains highly challenging. Here, nanocatalysts with ultralow Pt content and excellent performance supported on carbon black are designed by in-situ synthesis. These ~2 nm particles uniformly and stably dispersed on carbon black due to the strong s-p-d orbital hybridizations between carbon black and Pt which suppressed the agglomeration of Pt ions. This unique structure is beneficial for the hydrogen evolution reaction. The catalysts exhibited remarkable catalytic activity for hydrogen evolution reaction with a potential of 100 mV at 100 mA cm-2, comparable to commercial Pt/C; and mass activity (1.61 A/mg) is four times higher than that of commercial Pt/C (0.37 A/mg). The ultralow Pt loading of 6.84wt% paves the way for the development of next generation electrocatalysts.

The direct reduction process is an important development direction of low-carbon iron-making and efficient comprehensive utilization of poly-metallic iron ore, such as titanomagnetite. However, the defluidization of reduced iron particles with a high metallization degree at a high temperature will seriously affect the operation of fluidized bed reduction. Coupling the pre-oxidation enhancing reduction and the particle surface modification of titanomagnetite, the behavior and mechanism of pre-oxidation improvement on fluidization in the fluidized bed reduction of titanomagnetite are systematically studied in this paper. Pre-oxidation treatment of titanomagnetite can significantly lower the critical stable reduction fluidization gas velocity to 0.17 m/s while achieving a metallization degree > 90%, which is reduced by 56% compared to the critical gas velocity of titanomagnetite without pre-oxidation. Corresponding to the different reduction fluidization behaviors, three pre-oxidation operation regions have been divided, taking oxidation degrees 26% and 86% as the boundaries. Focusing on the particle surface morphology evolution in the pre-oxidation – reduction process, the relationship between the surface morphology of pre-oxidized ore and reduced iron with fluidization properties is built. The improving method of pre-oxidation on the reduction fluidization provides a novel approach to prevent defluidization by particle surface modification, especially for the fluidized bed reduction of poly-metallic iron ore.

To overcome the problem of element segregation in high entropy alloys and prepare uniform high entropy alloy coatings, FeCoCrNiMox composite powders were prepared by mechanical alloying technique, and it was prepared into high entropy alloy coatings with FCC phase by plasma spraying. The microstructure and phase composition of the coating were characterized by SEM, TEM, and X-ray diffraction. The coating’s hardness, elastic modulus, and fracture toughness were tested and the corrosion resistance was analyzed in simulated seawater. The results show that the hardness of the coating is 606.15 HV, the modulus of elasticity is 128.42 GPa and the fracture toughness is 43.98 MPa•m1/2. The corrosion potential of the coating in 3.5 wt.% NaCl solution is -0.49 V and the corrosion current density is 1.2×10-6A/〖cm〗^2. The electrochemical system consists of three parts: electrolyte, adsorption film and metallic oxide film produced during immerse, and FeCoNiCrMo high-entropy alloy coating. Over increasingly long periods, the corrosion reaction rate increases first and then decreases, the corrosion product film composed of metal oxides reaches a dynamic balance between formation and dissolution, and the internal reaction of the coating slows down.

With the continuous rise of the disposal volume for spent lithium-ion batteries (LIBs), properly recycling spent LIBs has become essential for advancing the circular economy. This study presents a systematic analysis of the chlorination-roasting kinetics and proposes a new two-step chlorination-roasting process for recycling lithium-ion battery cathode materials, integrating thermodynamics. The activation energy for the chloride reaction was determined to be 88.41 kJ/mol based on TG-DTG data using model-free, model-fitting, and Z(α) functions. The results indicated that the reaction was dominated by the First order (F1) model when the conversion rate was below 0.5 and shifted the Second order (F2) model when the conversion rate exceeded 0.5. The effects of roasting temperature, roasting time, and the mass ratio of NH4Cl to LiCoO2 were thoroughly investigated to determine the optimal conditions. Under the optimal parameters of 400°C for 20 minutes with a mass ratio of 3:1 for NH4Cl and LiCoO2, the leaching efficiency of Li and Co reached 99.43% and 99.05%, respectively. Analysis of the roasted products revealed that valuable metals in LiCoO2 transformed into CoCl2 and LiCl. Furthermore, to elucidate the reaction mechanism, providing insights into establishing a novel low-temperature chlorination roasting technology based on a crystal structure perspective. This technology can potentially guide the development of low-energy consumption, low-secondary pollution, high-recovery efficiency, and high-added value processes for LIB recycling.

In this work, multi-stage heat treatment involving quenching (Q), lamellarizing (L), and tempering (T) is applied in marine 10Ni5CrMoV steel to study the microstructure and mechanical properties by multi-scale characterizations, kinetics of reverse austenite transformation, strain hardening behavior, and toughening mechanism are further investigated. The specimens treated by lamellarizing process possess low yield strength but high toughness, especially cryogenic toughness. Introducing lamellarizing process leads to the film-like reversed austenite develops at martensite block and lath boundaries, which refines the martensite structure, and possess the lower equivalent grain size. Kinetic analysis of austenite reversion based on JMAK model shows that the isothermal transformation is dominated by the growth of reversed austenite, and there is a peak temperature (750°C) which makes the transformation of reversed austenite reach the maximum. The strain hardening behavior based on the modified Crussad-Jaoul analysis is indicated that reversed austenite obtained by lamellarizing process reduce the proportion of martensite, whereas produce a significant effect to hinder the propagation of cracks via martensitic transformation during the deformation, which are responsible for the QLT specimens exhibit high machinability and low yield strength. The ductile-brittle transition temperature of QLT specimens is decreased from -116°C to -130°C due to the low equivalent grain size and reversed austenite, which increase the cleavage force required for the propagation of cracks, and absorb the energy of external load, respectively. This work provides an idea to improve the cryogenic toughness of marine 10Ni5CrMoV steel, and lays a theoretical foundation for the industrial application and comprehensive performance improvement.

Different types of gases need to escape through the top of the mold during the continuous casting process of high-Mn high-Al steels. The behavior of bubbles passing through the liquid slag is the restrictive link, which is related to the viscosity. Compared with two-dimensional surface observation, three-dimensional analysis is more intuitive, accurate and comprehensive. The spatial distribution and three-dimensional morphological of residual bubbles in mold flux under different basicity, different temperature and different holding time were obtained by three-dimensional X-ray microscope in this paper. The results indicate that when the basicity increases from 0.52 to 1.03, the temperature increases from 1423 K to 1573 K, the holding time increases from 10 s to 30 s, the mean feret diameter of the bubbles solidified in the mold flux gradually decreases. Increasing the basicity and temperature will decrease the viscosity of the mold flux and increase the bubble floating rate, increasing the holding time will increase the bubble floating distance, both leading to an increase in the removal rate of bubbles especially for the large. The findings of bubbles escape behavior provide guidance for the research of functions of low basicity mold flux for high-Mn and high-Al steel.

The ternary lithium-ion batteries (LIBs), widely used in new energy vehicles and electronic products, is known for its high energy density, wide operating temperature range, and excellent cycling performance. With the rapid development of the battery industry, the recycling of spent LIBs, due to their economic value and environmental concerns, has become a hot topic. To date, there is a wealth of literature on the recycling of spent LIBs, being designed to provide an efficient, economical, and environmentally friendly method for battery recycling. This article examines the latest developments in various technologies for recycling spent LIBs in both research and practical production, including pretreatment, pyrometallurgy, hydrometallurgy, pyro-hydrometallurgy, and direct regeneration. Suggestions are made for addressing challenges based on the benefits and disadvantages of each method. Finally, through a comparison of the feasibility and economic benefits of various technologies, the challenges faced by battery recycling are summarized, and future development directions are proposed.

Microstructures determine mechanical properties of steels, but in actual steel product process it is difficult to accurately control the microstructure to meet the requirements. General microstructure characterization methods are time consuming and results are not representative for overall quality level as only a fraction of steel sample was selected to be examined. In this paper, a macro and micro coupled 3D model was developed for non-destructively characterization of steel microstructures. For electromagnetic signals analysis, the relative permeability value computed by the micro cellular model can be used in the macro electromagnetic sensor model. The effects of different microstructure components on the relative permeability of duplex stainless steel (grain size, phase fraction and phase distribution) were discussed. The output inductance of an electromagnetic sensor was determined by relative permeability values and can be validated experimentally. The findings indicate that the inductance value of an electromagnetic sensor at low frequency can distinguish different microstructures. This method can be applied to real-time on-line characterize steel microstructures in process of steel rolling.

This study aims to investigate mechanical properties and failure mechanisms of layered rock with rough joint surfaces under direct shear loading. Cubic layered samples with dimensions of 100 × 100 × 100 mm were casted using rock-like materials, with anisotropic angle (α) and joint roughness coefficient (JRC) ranging from 15° to 75° and 2 ~ 20, respectively. The direct shear tests were conducted under the application of initial normal stress (σn) ranging from 1 ~ 4 MPa. The test results indicate significant differences in mechanical properties, acoustic emission (AE) responses, maximum principal strain fields, and ultimate failure modes of layered samples under different test conditions. The peak stress increases with the increasing α and achieves a maximum value at α = 60° or 75°. As σn increases, the peak stress shows an increasing trend, with correlation coefficients R² ranging from 0.918 to 0.995 for the linear least squares fitting. As JRC increases from 2 ~ 4 to 18 ~ 20, the cohesion increases by 86.32% when α = 15°, while the cohesion decreases by 27.93% when α = 75°. The differences in roughness characteristics of shear failure surface induced by α result in anisotropic post-peak AE responses, which is characterized by active AE signals when α is small and quiet AE signals for a large α. For a given JRC = 6 ~ 8 and σn = 1 MPa, as α increases, the accumulative AE counts increase by 224.31% (α increased from 15° to 60°), and then decrease by 14.68% (α increased from 60° to 75°). The shear failure surface is formed along the weak interlayer when α = 15° and penetrates the layered matrix when α = 60°. When α = 15°, as σn increases, the adjacent weak interlayer induces a change in the direction of tensile cracks propagation, resulting in a stepped pattern of cracks distribution. The increase in JRC intensifies roughness characteristics of shear failure surface for a small α, however, it is not pronounced for a large α. The findings will contribute to a better understanding of the mechanical responses and failure mechanisms of the layered rocks subjected to shear loads.

Transition metal sulfides have great potential as anode materials for sodium-ion batteries (SIBs) due to their high theoretical specific capacities. However, the inferior intrinsic conductivity and large volume variation during sodiation-desodiation processes seriously affect its high-rate and long-cycle performance, unbeneficial for the application as fast-charging and long-cycling SIBs anode. Herein, the three-dimensional porous Cu1.81S/nitrogen-doped carbon frameworks (Cu1.81S/NC) are synthesized by the simple and facile sol-gel and annealing processes, which can accommodate the volumetric expansion of Cu1.81S nanoparticles and accelerate the transmission of ions and electrons during Na+ insertion/extraction processes, exhibiting the excellent rate capability (250.6 mAh g-1 at 20 A g-1) and outstanding cycling stability (70% capacity retention for 6000 cycles at 10 A g-1) for SIBs. Moreover, the Na-ion full cells coupled with Na3V2(PO4)3/C cathode also demonstrate the satisfactory reversible specific capacity of 330.5 mAh g-1 at 5 A g-1 and long-cycle performance with the 86.9% capacity retention at 2.0 A g-1 after 750 cycles. This work proposes a promising way for the conversion-based metal sulfides for the applications as fast-charging sodium-ion battery anode.

For rationally manipulating the production quality of high-temperature metallurgical engineering, there are great challenges in understanding the processes owing to the dark-box chemical/electrochemical reactors. To overcome this issues, various in-situ characterization methods have been recently developed to study the interactions between the composition, micro-structure and solid-liquid interface of high-temperature electrochemical electrodes and molten salts. In this review, recent progresses of in-situ high-temperature characterization techniques are discussed to summarize the advances of understanding processes in metallurgy engineering. In-situ high-temperature technologies and analytic methods mainly include synchrotron X-ray diffraction (s-XRD), laser confocal microscopy (LSCM) and X-ray computed microtomography imaging (CT), which are important platform for analyzing the structure and morphology of the electrodes to reveal the complexity and variability of the electrode interfaces. In addition, laser-induced breakdown spectroscopy (LIBS), high-temperature Raman microspectroscopy and ultraviolet-visible spectroscopy (UV-vis) provide microscale characterizations on the composition and structure of molten salts. More importantly, the combination of CT and s-XRD techniques enables to investigate the chemical reaction mechanisms at the two-phase interface. Therefore, these in-situ methods are essential for analyzing the chemical/electrochemical kinetics of high-temperature reaction processes, establishing theoretical principles for the efficient and stable operation of chemical/electrochemical metallurgical processes.

Inconel 718 is the most popular nickel-based superalloy, extensively used in aerospace, automotive and energy industries owing to its extraordinary thermomechanical properties. The effects of different two-step solid solution treatments on microstructure and δ phase precipitation of Inconel 718 alloy were studied, and the transformation mechanism from γ" metastable phase to δ phase was clarified. The precipitates were statistically analysed by X-ray diffractometer test results. The results show that the content of δ phase increased with the increase in second step solid solution temperature. The changes of microstructure and δ phase were studied by scanning electron microscopy and transmission electron microscopy. Intragranular δ phase formed in Inconel 718 alloy with a second step solid solution temperature of 925°C, and its orientation relationship with γ matrix was determined as [1(—)00]δ//[011(—)]γ and (010)δ//(111)γ. Furthermore, Vickers hardness of different heat treatment samples was measured, and hardness of sample treated by second step solid solution treatment at 1010°C reached the maximum value of 446.84 HV.

In recent years, medium entropy alloys have become a research hotspot due to their excellent physical and chemical performances. By controlling reasonable elemental composition and processing parameters, the medium entropy alloys can exhibit similar properties to high entropy alloys and have lower preparation costs. In this paper, a FeCoNi medium entropy alloy precursor was prepared via sol-gel and co-precipitation methods, respectively, and FeCoNi medium entropy alloys were prepared by carbothermal and hydrogen reduction. The phases and magnetic properties of FeCoNi medium entropy alloy were investigated. Results showed that the decompose temperature of the precursor prepared by sol-gel and co-precipitation methods was 369 °C and 834 °C, respectively. FeCoNi medium entropy alloy was produced by carbothermal and hydrogen reduction at 1500 °C. Some carbon was detected in the FeCoNi medium entropy alloy prepared by carbothermal reduction. The FeCoNi medium entropy alloy prepared by hydrogen reduction had uniform composition, and showed a relative high purity. Moreover, hydrogen reduction product exhibited a higher saturation magnetization and lower coercivity.

High-entropy design is attracting growing interest as it offers unique structures and unprecedented application potential for materials. In this article, a novel high-entropy ferrite (CoNi)x/2(CuZnAl)(1-x)/3Fe2O4 (x = 0.25, 0.34, 0.40, 0.50) with a single spinel phase of space group Fd-3m was successfully developed by the solid-state reaction method. By tuning the Co-Ni content, the magnetic properties of the material, especially the coercivity, changed regularly, and the microwave absorption properties were improved. In particular, the effective absorption bandwidth of the material increased from 4.8 GHz to 7.2 GHz, and the matched thickness decreased from 3.9 mm to 2.3 mm, while the minimum reflection loss remained below -20 dB. This study provides a practical method for modifying the properties of ferrites used to absorb electromagnetic waves.

Using aeolian sand (AS) for goaf backfilling allows coordination of green mining and AS control. Cemented AS backfill (CASB) exhibits brittle fracture. Polypropylene (PP) fibers are good toughening materials. When the toughening effect of fibers is analyzed, their influence on the slurry conveying performance should also be considered. Additionally, cement affects the interactions among the hydration products, fibers, and aggregates. In this study, the effects of cement content (8wt%, 9wt% and 10wt%), PP fiber length (6, 9 and 12 mm) and dosage (0.05wt%, 0.1wt%, 0.15wt%, 0.2wt% and 0.25wt%) on fluidity and mechanical propertity of the fiber–toughened CASB (FCASB) were analyzed. The results indicated that with increases in the three aforementioned factors, the slump flow decreased, while the rheological parameters increased. Uniaxial compressive strength (UCS) increased with the increase of cement content and fiber length, and with an increase in fiber dosage, it first increased and then decreased. The strain increased with the increase of fiber dosage and length. The effect of PP fibers became more pronounced with the increase of cement content. Digital image correlation (DIC) test results showed that the addition of fibers can restrain the peeling of blocks and the expansion of fissure, and reduce the stress concentration of the FCASB. Scanning electron microscopy (SEM) test indicated that the functional mechanisms of fibers mainly involved the interactions of fibers with the hydration products and matrix, and the spatial distribution of fibers. On the basis of single–factor analysis, the response surface method (RSM) was used to analyze the effects of the three aforementioned factors and their interaction terms on the UCS. The influence surface of the two-factor interaction terms and the three-dimensional scatter plot of the three–factor coupling were established. In conclusion, the response law of the FCASB properties under the effects of cement and PP fibers were obtained, which provides theoretical and engineering guidance for FCASB filling.

High pressure die casting (HPDC) AlSi10MnMg alloy castings are widely used in the automobile industry. Mg can enhance the strength of the alloy with the sacrifice of the ductility. Heat treatment was generally adopted to resolve this drawback. With the development of large integrated die-casting parts, non-heat treatment Al alloys are strongly desired. In addition, the externally solidified crystals (ESCs) are often found in HPDC, which are detrimental to the mechanical properties of castings. In order to achieve high strength and toughness of non-heat treatment die-casting Al-Si alloy, AlSi9Mn alloy is used as matrix with the introduction of Zr, Ti, Nb and Ce elements. Their influences on the ESCs and mechanical properties were systematically investigated by combining three-dimensional reconstruction and thermodynamic simulation. Our results reveal that the addition of Ti element induced the increase of ESCs size and porosity. The following introduction of Nb could refine ESCs and decrease porosity. Meanwhile, the large-sized Al3(Zr, Ti) phases formed and degraded the mechanical properties. It was further confirmed that the subsequent introduction of Ce resulted in the poisoning effect and reduced mechanical properties.

The pervasive use of 5th generation mobile communication technology is driving electromagnetic wave (EW) absorbents towards high performances. The construction of heterointerfaces is crucial to the improvement of absorption ability. Herein, a series of ultralight composites with rational heterointerfaces (Co/ZnO@N-doped C/layer-stacked C, MSC) are fabricated by calcination with rational construction of sugarcane and CoZn-ZIFs. The components and structures of as-prepared composites were investigated, and their electromagnetic parameters could be adjusted by the content of CoZn-ZIFs. All the composites possess good EW absorption performances, especially for MSC-3. Its optimal minimum reflection loss and effective absorption band can reach to -42 dB and 7.28 GHz at the thickness of just 1.6 mm with 20 wt% filler loading. The excellent performances are attributed to the synergistic effect of dielectric loss stemming from the multiple heterointerfaces and magnetic loss induced by magnetic single Co. And the sugarcane-derived layer-stacked carbon and formed consecutive conductive networks and could further dissipate the electromagnetic energy through multiple reflection and conduction loss. Moreover, the simulated radar cross section (RCS) technology manifests that MSC-3 possesses outstanding EW attenuation capacity under realistic far-field conditions. This study provides a strategy for building efficient absorbents based on biomass.

The utilization of iron coke provides a green pathway for low-carbon ironmaking. To uncover the influence mechanism of iron ore on the behavior and kinetics of iron coke gasification, the effect of iron ore on the microstructure of iron coke was investigated. Furthermore, a comparative study of the gasification reactions between iron coke and coke was conducted through non-isothermal thermogravimetric method. The findings indicate that compared to coke, iron coke exhibits an augmentation in micropores and specific surface area, and the micropores further extend and interconnect. This provides more adsorption sites for CO2 molecules during the gasification process, resulting in a reduction in the initial gasification temperature of iron coke. Accelerating the heating rate in non-isothermal gasification can enhance the reactivity of iron coke. The metallic iron reduced from iron ore is embedded in the carbon matrix, reducing the orderliness of the carbon structure, which is primarily responsible for the heightened reactivity of the carbon atoms. The kinetic study indicates that the random pore model can effectively represent the gasification process of iron coke due to its rich pore structure. Moreover, as the proportion of iron ore increases, the activation energy for the carbon gasification gradually decreases, from 246.2 kJ/mol for coke to 192.5 kJ/mol for iron coke 15%.

Deriving PC materials through biomass sources is a sustainable, ubiquitous, and low-cost method, which comes with many desired features, such as hierarchical texture, periodic pattern, and some unique nanoarchitecture. Herein, a new strategy of using Peanuts as Honeycomb-like carbon precursors and Fe3O4 as magnetic precursor to prepare excellent performance absorbing materials. During the carbonization process, the Peanut-shell changes into the interconnected Honeycomb-like porous carbon materials, and the precursor ferric salt converts into magnetic Fe3O4 nanoparticles. As a result, the obtained MA materials P-C-800@Fe3O4(1:0.5) exhibit outstanding MA performance. When the ration reaches at 4:6, it displays the minimum reflection Loss(RL) of -59.2 dB at 3.36mm, and the effective absorption bandwidth (RL<-10 dB) can reach 7.5 GHz(from 9.5 to 17 GHz) at 2.0 mm. The honeycomb-like composite materials, interfacial polarization, synergistic enhancement between dielectric loss and magnetic loss, multiple reflections, and scatterings make enhancement to the MA capability. This paper might provide an effective and facile strategy to prepare magnetic honeycomb-like porous carbon derived from biomass for MA applications.

Graphitized spent cathode carbon (SCC) is a hazardous solid waste generated in the aluminum electrolysis process. In this study, a process of flotation-acid leaching is proposed to purify the graphitized SCC, and its use as an anode material for lithium-ion batteries is explored. Optimization of the flotation and acid leaching processes was carried out separately using one-way experiments. The best performance was achieved at 90% flotation particle size of -200 mesh, slurry concentration of 10%, rotation speed of 1600 r/min, inflatable capacity of 0.2 m3/h, and SCC carbon content of 93%. Subsequently, the SCC carbon content reached 99.58% at a leaching concentration of 5 mol/L, a leaching time of 100 min, a leaching temperature of 85 ℃, and an HCl/FSCC volume ratio of 5:1. The purified graphitized SCC(FSCC-CL) was used as an anode material with an initial capacity of 348.2 mAh/g at 0.1C and a reversible capacity of 347.8 mAh/g after 100 cycles. Compared with commercial graphite, FSCC-CL has better reversibility and cycle stability. Therefore, after purification, SCC is an important anode material candidate, and this method also provides a feasible way for the resourceful recycling of SCC.

The element distribution and microstructure near surface of a high-Mn high-Al austenitic low-density steel were investigated after isothermal holding at temperatures ranging from 900°C to 1200°C in different atmospheres, including air, N2 and N2 + CO2 mixed atmospheres. The results show that no ferrite formed near the surface of the experimental steel during isothermal holding at 900°C and 1000°C in air, while ferrite formed near the surface when the isothermal temperature reached 1100°C and 1200°C. The fraction of ferrite was larger at 1200°C because more C and Mn diffused to the surface and exuded from steel, which then reacted with N and O to form oxidation products. The thickness of compound scale increased due to the larger diffusion rate at a higher temperature. In addition, after isothermal holding at 1100°C in N2, Al content near the surface reduced slightly, while the contents of C and Mn did not change. Therefore, no ferrite formed near the surface. However, the contents of C and Al near the surface reduced after holding at 1100°C in N2 + CO2 mixed atmosphere, resulting in a small amount of ferrite. The thickness of compound scale was found to be the thickest in N2, followed by N2 + CO2 mixed atmosphere, and the thinnest in air. Overall, the element loss and ferrite fraction were the largest after holding in air at the same temperature. The differences in element loss and ferrite fraction were small in N2 and N2 + CO2 mixed atmospheres, but the compound scale formed in N2 was significantly thicker. Based on these results, the N2 + CO2 mixed atmosphere is the most ideal heating atmosphere for industrial production of high-Mn high-Al austenitic low-density steel.

This study investigates the second phase evolution mechanism of κ-carbides during the aging process of Fe-28Mn-10Al-0.8C low-density steel (wt%) and its impact on the material's properties. Under different heat treatment conditions, intragranular κ-carbides exhibit various morphologies and crystallographic characteristics, such as acicular, spherical, and short rod-like shapes. At the initial stage of aging, κ-carbides primarily precipitate in acicular forms, accompanied by a few spherical carbides. With the extension of aging time, κ-carbides grow and coarsen, the spherical carbides significantly reduce, and the rod-like carbides become noticeably coarser. In the literature on low-density steel, κ-carbides primarily precipitate in the form of nanoscale particles from within austenite grains, with limited mention within ferrite matrix grains; furthermore, the second-phase evolution mechanism during the aging process remains unclear in the observations made in this experiment. By adjusting the aging temperature and time, this study thoroughly analyzed the crystallographic characteristics and morphological evolution of κ-carbides and investigated the impact of these changes on the material's microhardness. It comprehensively assessed the influence of different aging conditions on material properties and, based on these findings, proposed potential strategies for improving material strength.

The atmospheric corrosion monitoring (ACM) technique has been widely employed to track the real-time corrosion behavior of metal materials. However, limited studies have employed ACM to monitor the corrosion protection properties of organic coatings. This study focused on comparing a bare epoxy coating with one containing zinc phosphate corrosion inhibitors, both applied on ACM sensors, to observe their corrosion protection properties over time. The coatings underwent artificial damage via scratches and were then exposed to immersion as well as alternating dry and wet environments. This allowed for monitoring the galvanic corrosion currents in real-time. Throughout the corrosion tests, the zinc phosphate/epoxy coating displayed significantly lower ACM currents compared to the blank epoxy coating. The trend in ACM current variations closely matched the results obtained from regular electrochemical tests and surface analysis. This alignment highlights the potential of the ACM technique in evaluating the corrosion protection capabilities of organic coatings. Compared with the blank epoxy coating, the much decreased ACM current values observed on the zinc phosphate/epoxy coating confirmed the effective inhibition of zinc phosphate against steel corrosion beneath the damaged coating.

 Herein, ferrocene and a nitrogen heterocyclic compound (either melamine or imidazole) were hyper-crosslinked via an external crosslinker through a straightforward Friedel–Crafts reaction, leading to the formation of nitrogen-containing hyper-crosslinked ferrocene polymer precursors (HCPs). These precursors were subsequently carbonized to produce iron–nitrogen-doped porous carbon absorbers (Fe-NPCs). The Fe-NPCs feature a porous structure comprising aggregated nanotubes and nanospheres, with porosity that can be modulated by adjusting the iron and nitrogen content to optimize impedance matching. The use of hyper-crosslinked ferrocenes in constructing porous carbon ensures the uniform distribution of Fe-NxC, N dipoles, and α-Fe within the carbon matrix, providing the absorber with numerous polarization sites and a conductive network. The specially designed Fe-NPC-M2 absorbers exhibit satisfactory electromagnetic wave absorption performance, with a minimum reflection loss of −55.3 dB at 2.5 mm and an effective absorption bandwidth of 6.00 GHz at 2.0 mm. This research introduces a novel method for developing highly efficient carbon-based absorbing agents by utilizing hyper-crosslinked polymers as precursors.

A high-zinc 12vol%SiC/Al-13.3Zn-3.27Mg-1.07Cu (wt%) composite with ultra-high strength of 781 MPa was successfully fabricated by powder metallurgy method followed by extrusion process. The effects of solid solution and aging heat treatments on the microstructure and mechanical properties of the composite were investigated in detail. Compared to the single-stage solution treatment, more sufficient solid solution effect was achieved in two-stage solution treatment (470ºC/1 h+480ºC/1 h) due to the higher solution degree and more uniform microstructure. According to aging harden curves of the composite, the optimized aging parameter (100ºC/22 h) was proposed. By decreasing the aging temperature and shortening the aging time, the nanoscale precipitates became finer and more uniform, but the increase in the tensile strength was insignificant. Based on the fractography analysis, the intergranular cracking and interface debonding were considered as the main fracture mechanisms in the ultra-high strength SiC/Al-Zn-Mg-Cu composites. The SiC/Al interface with many compounds and the precipitate free zone at the high-angle grain boundaries were the relatively weak regions that could clearly limit the strength enhancement of the composite. The interfacial compounds were identified as MgO, MgZn2, and Cu5Zn8, which reduced the interface bonding strength and lead to interfacial debonding.

Recently, peroxymonosulfate-based advanced oxidation processes have turned out to be the one of most efficient approaches for the elimination of toxic and refractory organic pollutants from sewage. Because the electron withdrawing group SO4− was easily activated to release reactive species, including sulfate radical (·SO4−), hydroxyl radical (·OH), superoxide radicals (·O2-) and singlet oxygen (1O2), all of which could induce the degradation of organic contaminant. In this work, we had synthesized a variety of M-OMS-2 nanorods (M=Co, Ni, Cu or Fe), by doping of Co2+, Ni2+, Cu2+ or Fe3+ into manganese oxide octahedral molecular sieve (OMS-2), as high-efficiency nano-catalysts for efficient removal of sulfamethoxazole via peroxymonosulfate (PMS) activation. The comparison of catalytic performance of M-OMS-2 in sulfamethoxazole elimination via PMS activization exhibited that the order of sulfamethoxazole removal rate as follow: Cu-OMS-2 (96.4%) > Co-OMS-2 (88.0%) > Ni-OMS-2 (87.2 %) > Fe-OMS-2 (35.0%) > OMS-2 (33.5%). Then, the kinetics and structure-activity relationship of M-OMS-2 nanorods in the elimination of sulfamethoxazole were investigated. The feasible mechanism of sulfamethoxazole degradation via Cu-OMS-2/PMS system was further investigated by quenching experiment, HR-MS and EPR. In addition, we found that sulfamethoxazole degradation efficiency was obviously boosted in both sea water and tap water, demonstrating the great potential application of Cu-OMS-2/PMS system in the real sewage treatment.

The stable and low-carbon production of iron relies on the safety and longevity of key blast furnace equipment. This paper presents an analysis of the heat transfer characteristics of these components, as well as the uneven distribution of cooling water in parallel pipes based on hydrodynamic principles. Feasible methods for improving blast furnace cooling intensity are also discussed. Additionally, this study reviews the preparation process, performance, and damage characteristics of three key pieces of equipment: coolers, tuyeres, and hearth refractories. To better control these critical components under high-temperature working conditions, optimized technologies such as blast furnace operation and maintenance technology, self-repair technology, and full life cycle management technology are proposed. Finally, further research into safety assessments and predictions for key blast furnace equipment under new operating conditions is proposed.

Electromagnetic interference is of urgent concern in contemporary society, necessitating the swift advancement of substances with exceptional capabilities in absorbing electromagnetic waves. In this work, a direct hydrothermal method was utilized to create CoFe2O4/residual carbon from coal gasification fine slag (CFO/RC) composites. These composites encompass various mechanisms for microwave absorption, including conductive loss, natural resonance, interfacial dipole polarization, and magnetic flux loss. Consequently, compared with pure residual carbon materials this composite offers superior capabilities in microwave absorption. At 7.76 GHz, the CFO/RC-2 composite achieves an impressive minimum reflection loss (RLmin) of −43.99 dB with a thickness of 2.44 mm. Moreover, CFO/RC-3 demonstrates an effective absorption bandwidth (EAB) of up to 4.16 GHz, accompanied by a thickness of 1.18 mm. This study revealed the remarkable ability of the composite to diminish electromagnetic waves, providing a new method for generating microwave absorbing materials of superior quality.

During aircraft, ship, and automobile manufacturing, lap structures are frequently produced between aluminum alloy skins, wall panels, and stiffeners. However, the occurrence of lap defects severely decreases mechanical properties during friction stir lap welding (FSLW). This study focuses on investigating the effects of rotation rate, multi-pass welding, and cooling methods on lap defect formation, microstructure evolution, and mechanical properties. It was discovered that the hook defects were eliminated by decreasing the welding speed, applying 2-passes FLSW with a small welding tool, and introducing the additional water cooling, leading to a remarkable increase in effective sheet thickness and lap width. This strategy leads to a defect-free joint with an ultrafine-grained microstructure, elevating the tensile shear force from 298 N/m to 551 N/mm. The fracture behavior of FSLW was systematically studied, and a fracture factor of the lap joint was proposed to predict the fracture mode of the FSLW joint. Through the implementation of decreasing rotation rate, 2-passes welding, and the additional water cooling strategies, the enlarged, strengthened, and defect-free lap zone with refined ultrafine grains was achieved, comparable to the quality of lap welds for 7xxx Al alloys. Importantly, this study provides a valuable welding method for FSLW to eliminate hook defects and improve joint performance.

Biopolymers have been widely used as triboelectric materials in constructing self-powered sensing system, whereas the annihilation of triboelectric charges at high temperatures restricted the output signals as well as the sensitivity of assembled sensors. Herein, a novel chitosan/montmorillonite/lignin (CML) composite film was designed and employed as the tribopositive layers in assembling self-powered sensing system under hot conditions (25-70oC). Originating from the strong intermolecular interaction between biopolymers and nanofillers, the dense contact surface restrained the volatilization of induced electrons. The optimized CML-TENG delivered the highest open circuit voltage (Voc) of 262 V and a maximum instantaneous output power of 429 mW/m2. Furthermore, the best CM5L3-TENG retained 66% of its initial Voc at 70℃, which is much higher than the pristine chitosan film (39%). Our work provides a new strategy to suppress the annihilation of triboelectric charges at high temperatures, boosting the development of self-powered sensing device under hot conditions.

In order to conduct more extensive research on the application of ionic liquids (ILs) as collectors in minerals flotation, ethanol (EtOH) was used as a solvent to dissolve hydrophobic ILs to simplify the reagent regime. Some interesting phenomena were observed that EtOH caused different effects on the flotation efficiency of two ILs with similar structures. When EtOH was used to dissolve 1-Dodecyl-3-methylimidazolium chloride (C12[mim]Cl), and C12[mim]Cl as collector for pure quartz flotation tests at the concentration of 1*10-5mol*L-1, quartz recovery increased from 23.77% to 77.91% compared with ILs dissolved in water. However, quartz recovery of 1-Dodecyl-3-methylimidazolium hexafluorophosphate (C12[mim]PF6) decreased from 60.45% to 24.52% in the same cases. the EtOH concentration tests under 1*10-5mol*L-1 ILs and the ILs concentration tests under 2% EtOH confirmed this. After being affected by EtOH, the mixed ore flotation tests of quartz and hematite showed a decrease in the hematite concentrate grade and recovery for C12[mim]Cl collector, while the hematite concentrate grade and recovery for C12[mim]PF6 collector both increased. Based on these interesting differences and observation in flotation tests, the two-phase bubble observation tests were carried out and it showed that EtOH promoted foam height of two ILs during aeration but accelerated static froth defoaming after aeration stopped, and the foam of C12[mim]PF6 defoaming more quickly. Through the discussion of flotation tests and foam observation, an attempt was made to explain the reasons and mechanisms of various differences phenomenon using the dynamic surface tension effect and solvation effect result from EtOH. The solvation effect was verified by IR, XPS and Zeta potential tests. It can be assumed that although EtOH has a negative effect on the adsorption of ILs on the ore surface during the flotation process, it has application reference value for the inhibition of foam merging during the flotation aeration process and the acceleration of the defoaming of static foam. These effects induced a stronger secondary enrichment in the mixed ore flotation of C12[mim]PF6 collector, so that C12[mim]PF6 obtained good mixed ore separation under the condition of no any inhibitor.

This study aimed to investigate the impact of varying contents of pyrite on copper in the presence of different regrinding conditions, which were altered by using two types of grinding media, iron and ceramic balls, followed by flotation in the cleaner stage. It was found that the flotation performance of rougher copper concentrate can be improved by changing the regrinding conditions based on the content of pyrite. SEM-EDS (scanning electron microscope), X-ray spectrometer, EDTA extraction and XPS (X-ray photoelectron spectroscopy) studies illustrated that when the pyrite content was high, using iron media to regrind was beneficial to promote the generation of hydrophilic FeOOH on the surface of pyrite and improve copper grade. While using ceramic media for low pyrite content would avoid too much FeOOH covering the surface of chalcopyrite. Electrochemical studies further showed that the galvanic corrosion current of chalcopyrite-pyrite increased with the addition of pyrite and became stronger with the participation of iron media.

The structure of the oxide film on FGH96 alloy powders significantly influence mechanical properties of superalloys. In this study, FGH96 alloy powders with various oxygen contents were investigated by HRTEM and 3DAP techniques to elucidate the structure evolution of the oxide film. EDS analysis reveals the presence of two distinct components in the oxide film of the alloy powders: Amorphous oxide layer covering the γ matrix and amorphous oxide particles above the carbide. The alloying elements within the oxide layer emerges a laminated distribution, followed by Ni, Co, Cr, Al/Ti, which is attributed to the decreasing oxygen equilibrium pressure as oxygen diffuses from the surface into the γ matrix. On the other hand, Ti enrichment was observed in the oxide particles caused by the oxidation and decomposition of the carbide phase. Comparative analysis of the oxide film with oxygen contents of 140 ppm, 280 ppm, and 340 ppm shows similar elements distributions, while the thickness of the oxide film varies approximately at 9 nm, 14 nm, and 30 nm, respectively. These findings provide valuable insights into the structure of FGH96 alloy powders.

Cobalt plays an indispensable role in stabilizing the lattice structure of high-capacity Ni-rich cathode materials. However, the extravagant price and toxicity still limit its development. Generally, it is feasible for the use of transition metal substitution to reduce the Co content. Whereas the conventional co-precipitation method could not meet the requirements of multi-element co-precipitation and uniform distribution of elements due to the differences between element concentration and deposition rate. Herein, spray pyrolysis is introduced to prepare LiNi_0.9Co_0.1-xW_xO₂ (LNCW). Particularly, the pyrolysis behavior of ammonium metatungstate is studied together with the W substitution for Co. With the feasibility of spray pyrolysis, the Ni-Co-W contained oxide precursor shows a homogeneous distribution of metal elements, which is beneficial to uniform substituting of W in the final materials. It is found that with W substitution, the size of primary particles shows a decreasing trend from 338.06 nm to 71.76 nm and the cation disordering is low to 3.34%. As a result, the prepared LNCW shows significantly improved electrochemical performance. In the optimal conditions, the lithium-ion battery assembled with the LiNi_0.9Co_0.025W_0.075O₂ (LNCW-0.75%) sample exhibits enhanced capacity retention of 82.7% after 200 cycles, which provides insight into the development of Ni-rich and low-cobalt materials. The results show that W can compensate for the loss caused by Co deficiency to a certain extent.

Pyrolusite comprise as the foremost manganese oxides and a major source of manganese production. Application of an innovative hydrogen-based mineral phase transformation technology to pyrolusite is proposed, where 96.44% distribution rate of divalent manganese(Mn²⁺) at an optimum roasting temperature of 650 °C, a roasting time of 25 min, and an H₂ concentration of 20 at.% was observed, at which time the manganese existed predominantly in the form of manganosite. This study investigated the generation mechanism of manganosite from the viewpoint of reduction kinetics, phase transformation and structural evolution of pyrolusite, indicating that the high temperature contributes toward improvement of the distribution rate; while the optimal kinetic model for the reaction the A_3/2 model of random nucleation and subsequent growth with an activation energy (E) of 24.119 kJ·mol^-1 and a pre-exponential factor A of 0.03229 s^-1. Throughout the process of mineral phase transformation, the manganese oxide from the outer layer of particles to move inward to the core. In addition, pyrolusite follows the reduction sequence of MnO₂→Mn₂O₃→Mn₃O₄→MnO, and the reduction of manganese oxides in each valence state proceeds simultaneously. The findings provide a significant insight into the efficient and clean utilization of pyrolusite.

Two near final shape continuous casting process (direct strip casting (DSC) and compact strip production (CSP)) combined quenching & partitioning (Q&P) heat treatment routes were applied to a low carbon Si–Mn steel to create different initial microstructure before heat treatment and finally obtain a new combination of mechanical properties. The initial structure of the DSC sample is a composite structure of lath martensite and bainite. Compared with the pearlite and ferrite initial structure of CSP sample, the DSC as-cast sample shows higher comprehensive mechanical properties. After the same Q&P treatment, the DSC samples generally showed better comprehensive mechanical properties compared to the CSP samples. An optimum comprehensive mechanical property was achieved in DSC-Pt300 samples with yield strength (YS) ~ 1282 MPa, ultimate tensile strength (UTS) ~ 1501 MPa, total elongation (TE) ~ 21.5% and the production of strength and elongation (PSE) higher to 32.3 GPa%. The enhanced mechanical properties were discussed based on the distribution characteristics of each phase in the matrix, the volume fraction and carbon content of retained austenite (RA). This work has achieved the goal of obtaining excellent mechanical properties in the low-alloy trip-assisted Si-Mn steel through a simple process, demonstrating the superiority of DSC technology in manufacturing AHSSs, which has important guiding significance for the short process production of AHSSs.