In this research, high calcium-fly ash (HCFA) collected from the Mae Moh electricity generating plant in Thailand was utilized as a raw material for ceramic production. The main compositions of HCFA characterized by XRF mainly consisted of 28.55 wt% SiO₂, 16.06 wt% Al₂O₃, 23.40 wt% CaO and 17.03 wt% Fe₂O₃. Due to high proportion of calcareous and ferruginous contents, HCFA was used for replacing the potash feldspar in amounts of 10-40 wt%. The influence of substituting high-calcium fly ash (0-40 wt%) and sintering temperatures (1000-1200 ^οC) on physical, mechanical, and thermal properties of ceramic-based materials was investigated. The results showed that the incorporation of HCFA in appropriate amounts could enhance the densification and the strength as well as reduce the thermal conductivity of ceramic samples. High proportion of calcareous and ferruginous constituents in fly ash promoted the vitrification behavior of ceramic samples. As a result, the densification was enhanced by liquid phase formation at optimum fly ash content and sintering temperature. In addition, these components also facilitated a more abundant mullite formation and consequently improved flexural strength of the ceramic samples. The optimum ceramic properties were achieved with adding fly ash content between 10-30 wt% sintered at 1150-1200 ^οC. At 1200 ^οC, the maximum flexural strength of ceramic-FA samples with adding fly ash 10-30wt% (PSW-FA(10)-(30)) was obtained in the range of 92.25-94.71 MPa when the water absorption reached almost zero (0.03%). In terms of thermal insulation materials, the increase in fly ash addition had a positively effect on the thermal conductivity, due to the higher levels of porosity created by gas evolving from the inorganic decomposition reactions inside the ceramic-FA samples. The addition of 20-40 wt% high-calcium fly ash in ceramic samples sintered at 1150 ^οC reduced the thermal conductivity to 14.78-49.25%, while maintaining acceptable flexural strength values (~ 45.67-87.62 MPa). Based on these promising mechanical and thermal characteristics, it is feasible to utilize this high-calcium fly ash as an alternative raw material in clay compositions for manufacturing of ceramic tiles

In this study, the effect of Mg replacement with Al on the discharge capacity of Mg₂Cu powder mixture is investigated. The mixture of nanocrystalline powder is prepared via mechanical alloying (MA) technique with a high energy planetary ball mill. In addition, different moles of Al are substituted to Mg₂Cu powder (0.05, 0.1, 0.15, 0.2, and 0.3). X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) are used to analyze changes in structure, morphology, and grain size. The obtained powder is utilized as an anode in a nickel-metal hydride battery (Ni-MH). In the specimens with 0.05 M Al content, the orthorhombic structure of Mg₂Cu is emerged after 5 hours milling. The results reveal that more than 0.2 M Al substitution leads to an appearance of MgCu₂ peaks. Al substitution does not affect microstructure uniformity; however, it causes a decrease in crystalline size and lattice parameters. The SAD pattern elucidates that the electrode with the Mg_1.9Al_0.1Cu chemical composition and 20 hours milling has the maximum discharge capacity.

Effectively extracting lithium from the pyrometallurgical slag of spent lithium-ion batteries at a relatively low temperature remains a great challenge. Herein, potassium carbonate/sodium carbonate (K₂CO₃/Na₂CO₃) which could form eutectic molten salts at 720°C were used as the roasting agents for extracting lithium from the pyrometallurgical slag. The lithium is successfully extracted from slag by K₂CO₃/Na₂CO₃ roasting followed by water leaching. According to the theoretical calculation results, lengths of Li-O bonds increase after adsorption of K⁺/Na⁺, resulting in easily release of Li⁺ from the lattice of LiAlSi₂O₆ after roasting with K₂CO₃/Na₂CO₃. Moreover, the TG-DSC results indicate that the eutectic phenomenon of K₂CO₃ and Na₂CO₃ is observed at 720°C and the reaction of slag and eutectic molten salts happens above 720°C. The X-ray diffraction results suggest that Li⁺ in slag is exchanged by K⁺ in K₂CO₃ which is accompanied by the formation of KAlSiO₄, while Na₂CO₃ is mainly employed as a fluxing agent. The lithium extraction efficiency can reach 93.87% under the following optimal conditions: roasting temperature of 740°C, roasting time of 30 min, leaching temperature of 50°C, leaching time of 40 min and water/roasted samples mass ratio of 10:1. This work provides a new system for extracting lithium from the pyrometallurgical slag of spent lithium-ion batteries.

The effectiveness of Ca or Gd addition on ductility and formability of Mg-Zn-Zr based dilute alloys in deep drawing has not been systematically compared previously. In this study, formable Mg-Zn-Gd-Zr and Mg-Zn-Ca-Zr sheet alloys are produced by hot rolling. These sheets have similarly weakened basal texture, but the sheet of the Mg-Zn-Gd-Zr alloys has higher ductility and formability than that of Mg-Zn-Ca-Zr alloys. The combined addition of 0.2 wt.% Ca and 0.4 wt.% Gd to the Mg-1Zn-0.5Zr (wt.%) alloy leads to a Mg-1Zn-0.4Gd-0.2Ca-0.5Zr alloy that has even better ductility and its formability during deep drawing is comparable to the benchmark Al6016 sheet. An increase in Ca concentration from 0.2 wt.% to 0.5 wt.% leads to decreased sheet ductility and formability, predominantly due to grain boundary embrittlement.

Understanding the structural and electronic properties of calcium silicates is crucial to reveal their difference in hydration reactivity. Here we presented a comprehensive comparison of β-C₂S and M₃-C₃S. The structural properties and Bader charge of β-C₂S and M₃-C₃S in the unit cell, during surface reconstruction and after single water adsorption were investigated using density functional theory. We identified different types of atoms in β-C₂S and M₃-C₃S considering the bonding characteristics and Bader charge. For β-C₂S, Ca atoms were divided into two groups and O atoms into four groups. For M₃-C₃S, Ca atoms were divided into four groups, O atoms into four groups, and Si atoms into three groups. The valance electron distribution on the surface was more uniform than that of the unit cell, indicating some atoms became more reactive after surface relaxation. During water adsorption, electrons of β-C₂S and M₃-C₃S were transferred from the surface to the adsorbed water molecules through position re-distribution and bond formation/breaking. And on this basis, we explored the reason why β-C₂S and M₃-C₃S had activity differences. A type of O atom with special bond characteristics (no O-Si bonds) and high reactivity was observed in the unit cell of M₃-C₃S. As revealed by Bader charge analysis, the reactivity of Ca and O atoms was generally higher in M₃-C₃S than in β-C₂S. The average valence electron number of Ca/O atoms in β-C₂S was 6.437/7.550, while in M₃-C₃S it was 6.481/7.537. Moreover, the water molecules in M₃-C₃S gained more electrons at the surface compared to β-C₂S. The average valence electron variation of H₂O on β-C₂S was 0.041 while that on M₃-C₃S was 0.226.

Cr³⁺-activated far-red and near-infrared phosphors have drawn much attention owing to their adjustable emission wavelengths and wide applications. Herein, we report a series of Cr³⁺-doped phosphors with β-Ca₃(PO₄)₂-type structure, of which Ca₉Ga(PO₄)₇:Cr³⁺ possesses the highest far-red emission intensity due to its strong absorption band of Cr³⁺ ion. Under the excitation of 440 nm, Ca₉Ga(PO₄)₇:Cr³⁺ phosphors exhibit a broad emission band ranging from 650 to 850 nm peaking at 735 nm and superimpose two sharp lines centered at 690 and 698 nm. The optimal sample, Ca₉Ga_0.97(PO₄)₇:0.03Cr³⁺, has the internal quantum efficiency of 55.7%. The luminescence intensity of Ca₉Ga_0.97(PO₄)₇:0.03Cr³⁺ phosphor obtained at 423 K can maintain 68.5% of that at room temperature, demonstrating its outstanding luminescence thermal stability. Finally, a phosphor-conversion light-emitting diode was fabricated, indicating that Ca₉Ga(PO₄)₇:Cr³⁺ phosphor has potential applications in the field of indoor plant cultivation.

Lithium-rich materials possess ultra-high specific capacity, but the redox of oxygen is not completely reversible, resulting in voltage attenuation and structural instability. A stepwise co-precipitation method is used for the first time in this paper to achieve the control of the two-phase distribution through controlling the distribution of transition metal elements and realize the modification of particle surface structure without the aid of heterologous ions. The results of characterization tests show that the content of LiMO₂ phase inside the particles and the content of Li₂MnO₃ phase on the surface of the particles are successfully increased, and the surface induced formation of Li₄Mn₅O₁₂ spinel phase or some disorderly ternary. The electrochemical performance of the modified sample is as follows: LR (pristine) shows specific discharge capacity of 72.7 mA h g^-1 after 500 cycles at 1C, while GR (Modified sample) shows specific discharge capacity of 137.5 mA h g^-1 at 1C, and the discharge mid-voltage of GR still remains above 3 V when cycling to 220 cycles at 1C (mid-voltage of LR remains above 3 V when cycling to 160 cycles at 1C). Therefore, deliberately regulating the local state of the two phases is an successful way to reinforced the material structure and inhibition the voltage attenuation.

Self-assembled process for device functional layers is a simple, feasible and energy-saving strategy. In mesoporous PSCs, compact and scaffold TiO₂ films generally function as the hole blocking and electron transporting layers, respectively. However, they are both typically generated through high-temperature annealing. Here, we deposited TiO₂ compact films by a room-temperature self-assembled process, which were conducted as an effective hole blocking layer for perovskite solar cells. The thickness of TiO₂ compact films can be easily controlled by the deposition time. By optimizing the TiO₂ compact films (80 nm), the power conversion efficiency of mesoporous perovskite solar cells without and with hole conductor layers was up to 10.66% and 17.95%, respectively. Interestingly, an all-low-temperature planar perovskite solar cell with the self-assembled TiO₂ layer achieve power conversion efficiency of 16.42%.

A diatomite-based porous ceramic support has been prepared using solid-phase sintering and low-temperature calcination processes. Using diatomite as the main raw material, adding appropriate amount of tourmaline and sintering aids to the glaze, and combining different heat treatment temperatures of the glaze layer, tourmaline/diatomite-based interior wall tiles are prepared. The glaze layer under different heat treatment temperatures is characterized by thermogravimetric-differential thermal analysis, X-ray diffraction and scanning electron microscope. The influences of heat treatment temperature on the microscopic morphology and structure of the glaze layer are analyzed. Taking formaldehyde as the target degradation product, the effects of tourmaline/diatomite-based interior wall tiles on the removal of formaldehyde under different heat treatment temperatures of the glaze layer are investigated. The results show that with the increase of heat treatment temperature, the original pores of diatomite decreases, and the specific surface area, and the structure of tourmaline changes. The surface structure of the material is slightly damaged at 850℃, the strength is increased, and the removal effect of formaldehyde is better. In a 1 m³ environmental chamber, the formaldehyde removal rate reaches 73.6% in 300 min. When the temperature is increased to 950℃ and above, diatomite and the structure of tourmaline are destroyed, and the ability of the material to adsorb and degrade formaldehyde decreases.

The mica was used as a supporting matrix for composite phase change materials (PCMs) because of its distinctive morphology and structure in this work. Mica-based composite PCMs were prepared by vacuum impregnation method using mica as supporting material and polyethylene glycol (PEG) as phase change material. Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analysis confirmed that the addition of PEG had no effect on the crystal structure of mica, and no chemical reaction between PEG and mica during the vacuum impregnation process, and no new substance was formed. The maximum load of mica stabilized PEG is 46.24%, the phase change temperature of M400/PEG is 46.03°C, and the latent heat values of melting and cooling are 77.75 J g^-1 and 77.73 J g^-1, respectively. The thermal conductivity of M400/PEG is 2.4 times that of pure PEG. The thermal infrared images indicated that the thermal response of M400/PEG was improved compared with that of pure PEG. The leakage test confirmed that mica could stabilize PEG, and M400/PEG had great form-stabilized property. These results demonstrate that M400/PEG has potential in the field of building energy conservation.

In this paper, hot deformation behavior of Mn18Cr18N and Mn18Cr18N+Ce high nitrogen austenitic stainless steel at 1173~1473 K and 0.01~1 s^-1 are investigated by thermal compression tests. Influence mechanism of Ce on the hot deformation behavior is analyzed by Ce-containing inclusions and segregation of Ce. The results show that, after adding Ce, large, angular, hard and brittle inclusions (TiN-Al₂O₃, TiN and Al₂O₃) can be modified to fine and dispersed Ce-containing inclusions (Ce-Al-O-S and TiN-Ce-Al-O-S). During the solidification, Ce-containing inclusions can be used as heterogeneous nucleation particles to refine as-cast grains. During the hot deformation, Ce-containing inclusions can pin dislocation movement and grain boundary migration, induce dynamic recrystallization (DRX) nucleation, and avoid the formation and propagation of micro cracks and gaps. In addition, During the solidification, Ce atoms will enrich at the front of solid-liquid interface, resulting in composition supercooling and refining the secondary dendrites. Similarly, during the hot deformation, Ce atoms tend to segregate at the boundaries of DRX grains, inhibiting the growth of grains. Under the synergistic effect of Ce-containing inclusions and Ce segregation, although the hot deformation resistance and hot deformation activation energy are improved, DRX is more likely to occur and the size of DRX grains is significantly refined, and the problem of hot deformation cracking can be alleviated. Finally, the microhardness of samples was measured. The results showed that, compared with as-cast samples, the microhardness of hot-deformed samples increases significantly, and with the increase of DRX degree, the microhardness decreases continuously. In addition, Ce can affect the microhardness of Mn18Cr18N steel by affecting as-cast and hot deformation microstructure.

The effect of anodic polarization on plastic deformation behavior and formability of FeSi6.5 steel at room temperature was experimentally investigated through uniaxial tensile and drawing of wire specimen in sulfuric acid solution with current densities of 0-40 mA/cm². The formability of the FeSi6.5 steel was significantly improved after the anodic polarization. The plastic elongation of the specimen as an anode in the electrochemical environment was 4.4-7%, but 2.7% in the air. The drawing force under the anodic polarization decreased by 12.5-26% compared to that in deionized water. The softening is mainly attributed to the relief in work hardening caused by surface atomic dissolution. The work hardening mechanism of the FeSi6.5 steel wires under anodic polarization condition was analyzed using Hollomon equation and Voce relation combined with the K-M approach. These data support the view that the surface atom dissolution facilitates dislocation slip. FeSi6.5 steel wires were obtained using electrochemical cold drawing and presented a smooth surface and good ductility without crack after five-pass drawing with a total cross-section area reduction of 88%. The drawing with the assistance of anodic polarization is a promising technology for processing hard and brittle metal materials.

In this work, a low-alloyed Mg-2Zn-0.8Sr-0.2Ca matrix composite reinforced by TiC nano-particles is successfully prepared by semi-solid stirring under the assistance of ultrasonic and then the as-cast composite is hot extruded. The results indicate that the volume fraction of dynamical recrystallization and the recrystallized grain size have a certain decline at lower extrusion temperature or rate. The finest grain size of ~0.30 µm is obtained in the sample extruded at 200℃ and 0.1 mm/s. The as-extruded sample displays a strong basal texture intensity, and the basal texture intensity increases to 5.937 mud while the extrusion temperature increases from 200℃ to 240℃. The ultra-high mechanical properties (ultimate tensile strength of 480.2 MPa, yield strength of 462 MPa) are obtained after extrusion at 200℃ with a rate of 0.1 mm/s. Among all strengthening mechanisms for the present composite, grain refinement contributes the most to the increase in strength. A mixture of cleavage facets and dimples are observed in the fracture surfaces of three as-extruded nanocomposites, which explain a mix of brittle-ductile fracture way of the samples.

Transition metal phosphides (TMPs) have exhibited decent performance for oxygen evolution reaction (OER), which is a kinetic bottleneck in many energy storages and conversion systems. However, most reported catalysts are composed of three or fewer metallic components, and the investigation of Multicomponent TMPs with more than four metallic components is hindered by their intrinsic complexity in rationally design the structure and fundamentally comprehension in the component-activity correlation. Here, we reported a facile strategy for combining TMPs with tunable elemental compositions (Ni, Fe, Mn, Co, Cu) on a two-dimensional titanium carbide (MXene) flake through a hydrothermal growth and subsequent phosphorization. The obtained TMPs/MXene hybrid nanostructures present homogeneously distributed elements, high electrical conductivity, and strong interfacial interaction, resulting in an accelerated reaction kinetics and long-term stability. OER performance of catalysts with different components was compared and the results show that NiFeMnCoP/MXene is the most active one with a low overpotential of 240 mV at 10 mA cm^-2, a small Tafel slope of 41.43 mV dec^-1, and a robust long-term electrochemical stability. The electrocatalytic mechanism investigation revealed that the enhanced OER performance of NiFeMnCoP/MXene results from a strong synergistic effect of the multi-elemental composition. Our work, therefore, provides a scalable synthesis route for multi-elemental TMPs and a valuable guideline for designing efficient MXene-supported catalysts.

The ordinary cemented tailings backfill (CTB) was a cement-based composite prepared from tailings, cementitious materials and water. In this study, a series of laboratory tests including uniaxial compression, digital image correlation (DIC) measurement and scanning electron microscope (SEM) characteristics of fiber-reinforced CTB (FRCTB) was conducted to obtain the uniaxial compressive strength (UCS), failure evolution and microstructural characteristics of FRCTB specimens. The results have shown that: adding fibers could increase the UCS values of the CTB by 6.90 to 32.76%. The UCS value of the FRCTB increased with the PP fiber content increased. Besides, the reinforcement effect of PP fiber on the CTB was better than that of glass fiber. Besides, the addition of fiber could increase the peak strain of the FRCTB by 0.39 to 1.45%. And the peak strain of FRCTB increased with the glass fiber content increased. The failure pattern of FRCTB was coupled with tensile and shear failure. The addition of fiber effectively inhibited the propagation of cracks, and the bridging effect of cracks by the fiber effectively improved the mechanical properties of the FRCTB. The findings in this study can provide a basis for the backfilling design and optimization of backfilling method mining.

The objective of this work is to study the improvement effect of Sm on Mn-based catalysts for selective catalytic reduction (SCR) of NO with NH₃. A series of Sm_xMn_0.3–xTi catalysts (x = 0, 0.1, 0.15, 0.2, 0.3) were prepared by co-precipitation. The activity tests indicated that the Sm_0.15Mn_0.15Ti catalyst showed superior performances with NO conversion of 100% and N₂ selectivity above 87% at 180–300°C. The characterizations showed that the doping of Sm suppressed the crystallization of TiO₂ and Mn₂O₃ phases, and increased the specific surface area and acidity. Especially, the surface area increased from 152.2 m²·g⁻¹ of Mn_0.3Ti to 241.7 m²·g⁻¹ of Sm_0.15Mn_0.15Ti. These all contributed to the catalytic activity. The XPS results indicated that the relative atomic ratios of Sm³⁺/Sm and O_β/O of Sm_0.15Mn_0.15Ti were 76.77% and 44.11%, respectively. The existence of Sm contributed to the increase of surface absorbed oxygen (O_β) and the decrease of the surface concentration of Mn⁴⁺, which improved the catalytic activity. In the results of H₂-TPR, the presence of Sm induced higher reduction temperature and lower H₂ consumption (0.3 mmol g^–1) of Sm_0.15Mn_0.15Ti catalyst than that of Mn_0.3Ti catalyst. The decrease of Mn⁴⁺ weakened the redox property of the catalysts, and increased the N₂ selectivity by suppressing the formation of N₂O from both NH₃ oxidation and nonselective catalytic reduction reaction. The results of in situ DRIFT spectra revealed that the NH₃-SCR of NO over Sm_0.15Mn_0.15Ti catalyst mainly followed the Eley-Rideal mechanism. The Sm doping increases surface absorbed oxygen and weakens the redox property to improve the NO conversion and N₂ selectivity of Sm_0.15Mn_0.15Ti catalyst.

The Shima yield criterion used in finite element analysis for nickel-based superalloy powder compact during hot isostatic pressing (HIP) was modified through uniaxial compression experiments. The influence of cylindrical capsule characteristics on FGH4096M superalloy powder compact deformation and densification behavior during HIP was investigated through simulations and experiments. Results reveals the simulation shrinkage prediction fitted well with the experimental shrinkage including a maximum shrinkage error of 1.5%. It was shown that the axial shrinkage was 1.7% bigger than radial shrinkage for a cylindrical capsule with the size of Φ50 mm × 100 mm due to the force arm difference along the axial and radial direction of the capsule. The stress deviated from the isostatic state in the capsule led to the uneven shrinkage and non-uniform densification of the powder compact. The ratio of the maximum radial displacement to axial displacement increased from 0.47 to 0.75 with the capsule thickness increased from 2 mm to 4 mm. The pressure transmission was related to the capsule thickness and the capsule material performance, and physical parameters in the HIP process.

The dissolution kinetics of Al₂O₃ in CaO-Al₂O₃-SiO₂ slags was studied using high-temperature confocal scanning laser microscope at 1773 to 1873 K. The results show that the controlling step during the Al₂O₃ dissolution was diffusion in the molten slag. It was found that dissolution curves of Al₂O₃ particles was hardly agreed with the traditional boundary layer diffusion model with the increase of the CaO/Al₂O₃ of slag. A modified diffusion equation considering slag viscosity was developed to study the dissolution mechanism of Al₂O₃ in slag. Diffusion coefficients of Al₂O₃ in slag were calculated as 2.8 ×10^-10 to 4.1 ×10^-10 m²/s. The dissolution rate of Al₂O₃ increased with higher temperature, CaO/Al₂O₃, and particle size. A new model was shown to be v_Al2O3 = 0.16 × R₀^1.58 × x^3.52 × (T-T_mp)^1.11 to predict the dissolution rate and the total dissolution time of Al₂O₃ inclusions with various sizes.

Rechargeable aqueous magnesium-ion batteries (MIBs) show great promise for low-cost, high-safety, and high-performance energy storage applications. Although manganese dioxide (MnO₂) is considered as a potential electrode material for aqueous MIBs, the low electrical conductivity and unsatisfactory cycling performance greatly hinder the practical application of MnO₂ electrode. To overcome these problems, herein, a novel Mg-intercalation engineering approach for MnO₂ electrode to be used in aqueous MIBs is presented, wherein the structural regulation and electrochemical performance of the Mg-intercalation MnO₂ (denoted as MMO) electrode are thoroughly investigated by Density functional theory (DFT) calculations and in-situ Raman investigation. The results demonstrate that the Mg intercalation is essential to adjusting the charge/ion state and electronic band gap of MMO electrode, as well as the highly reversible phase transition of the MMO electrode during the charging–discharging process. Because of these remarkable characteristics, the MMO electrode can be capable of delivering a significant specific capacity of ~419.8 mAh g^-1, while exhibiting a good cycling capability over 1000 cycles in 1 M aqueous MgCl₂ electrolyte. On the basis of such MMO electrode, we have successfully developed a soft-packaging aqueous MIB with excellent electrochemical properties, revealing its huge application potential as the efficient energy storage devices.

Bi_0.5(Na_0.68K_0.22Li_0.10)_0.5Ti_1-xCo_xO₃ lead-free perovskite ceramics (BNKLT-xCo, x = 0, 0.005, 0.010, 0.015 and 0.020) were fabricated via the solid-state combustion technique. A small-amount of Co²⁺ ion substitution into Ti-sites led to modification of the phase formation, microstructure, electrical and magnetic properties of BNKLT ceramics. Coexisting rhombohedral and tetragonal phases were observed in all samples using the XRD technique. The Rietveld refinement revealed that the rhombohedral phase increased from 39 to 88 % when x increased from 0 to 0.020. The average grain size increased when x increased. With increasing x, more oxygen vacancies were generated, leading to asymmetry in the S-E loops. For the composition of x = 0.010, a high dielectric constant (_m) of 5384 and a large strain (S_max) of 0.23 % with d₃₃* (S_max/E_max) of 460 pm/V were achieved. The BNKLT-0Co ceramic showed diamagnetic behavior but all of the BNKLT-xCo ceramics exhibited paramagnetic behavior, measured at 50 K.

The recovery of vanadium (V) from stone coal by bioleaching is a promising method. The bioleaching experiments and the biosorption experiments were carried out, aiming to explore the adsorption characteristics of Bacillus mucilaginosus (B. mucilaginosus) on the surface of vanadium-bearing stone coal, and the related mechanisms have been investigated. After bioleaching at 30°C for 28 days, the cumulative leaching rate of V reached 60.2%. The biosorption of B. mucilaginosus on stone coal was affected by many factors. When the leaching system pH=5.0, strong electrostatic attraction between bacteria and stone coal promoted biosorption. Bacteria in the logarithmic growth phase had mature and excellent biosorption properties. The initial bacterial concentration of 3.5×10⁸ cfu/mL was conducive to adhesion, with 38.9% adsorption rate and 3.6×10⁷ cfu/g adsorption quantity. The adsorption of B. mucilaginosus on the stone coal conformed to the Freundlich model and the pseudo-second-order kinetic model. Bacterial surface carried functional groups (-CH₂, -CH₃, -NH₂, et al.), which were highly correlated with the adsorption behavior. In addition, biosorption changed the surface properties of stone coal, resulting in the isoelectric point (IEP) approaching the bacteria. The results of our study could provide an effective reference for the adsorption laws of bacteria on minerals.

Copper nanowires (CuNWs) are promising electrode materials, especially for being used in flexible and transparent electrodes, due to their advantages of earth-abundant, low-cost, high conductivity and flexibility. However, the poor stability of CuNWs against oxidation and chemical corrosion seriously hinders their practical applications. Herein, we propose a facile strategy to improve the chemical stability of CuNWs by in situ coating of carbon protective layer on top of them through hydrothermal carbonization method. The influential factors on the growth of carbon film including the concentration of the glucose precursor (carbon source), hydrothermal temperature and time are systematically studied. By tailoring these factors, carbon layers with thickness of 3-8 nm can be uniformly grown on CuNWs with appropriate glucose concentration around 80 mg mL^-1, hydrothermal temperature of 160-170 ℃, and hydrothermal time of 1-3 h. The as-prepared carbon-coated CuNWs show excellent resistance against corrosion and oxidation and are of great potential to be used broadly in various optoelectronic devices.

Li addition is verified to be an effective method to increase the room temperature ductility and formability of Mg alloys. In the present study, the microstructure, texture and tensile properties of extruded Mg–1Zn–xLi (wt%, x=0, 1, 3, 5) alloy sheets were studied by X-ray diffraction (XRD), scanning electron microscope (SEM), and electron backscatter diffraction (EBSD). It is found that Li addition resulted in the grain coarsening and the development of new transverse direction (TD)–tilting and 〈10–10〉 parallel to extrusion direction textures, which was related to the improved dynamic recrystallization and the increased prismatic slip during extrusion. The Mg–1Zn–5Li sheet showed the weakest texture, which contained both basal and TD–tilting oriented grains. No additional phase was formed with Li addition. Tensile properties showed that the yield strength of Mg–1Zn–xLi sheets gradually decreased with increasing Li content, which was mainly related to grain coarsening and texture weakening. In addition, the ductility of the Mg–1Zn–xLi sheet was remarkably enhanced by Li addition. The elongation of the Mg–1Zn–5Li sheet was 30.3% along the transverse direction, which was three times than that of Mg–1Zn sheet. Microstructural analysis implied that this significant ductility enhancement was associated with the improvement activation of prismatic and basal slips during the tensile tests. This study may provide insights into the development of high-ductility, low-density Mg–Zn–Li based alloys.

Al-Mg alloys are an important class of non-heat treatable alloys in which Mg solute and grain size play essential role in their mechanical properties and plastic deformation behaviors. In this work, a novel cyclical continuous expanded extrusion and drawing (CCEED) process was proposed and implemented on an Al-3Mg alloy to introduce large plastic deformation. The results showed that the continuous expanded extrusion mainly improved the ductility, while the cold drawing enhanced the strength of the alloy. With the increased processing CCEED passes, the multi-pass cross shear deformation mechanism progressively improved the homogeneity of the hardness distributions and refined grain size. The grain size of the processed Al-3Mg alloy rods was refined by continuous dynamic recrystallization. And the microstructural evolution was basically influenced by the special thermomechanical deformation conditions during the CCEED process.

Hexavalent chromium (Cr(VI)) compound is useful to various industries but is toxic and carcinogenic. In this research work, we fabricate an amperometric sensor for the determination of Cr(VI), using a titanium dioxide (TiO₂)-reduced graphene oxide (rGO) composite as the sensing element. The composite was synthesized following sol-gel chemistry, yielding TiO₂ nanoparticles of ~50 nm in size, immobilized on chemically exfoliated rGO sheets. The composite was employed in a 3-electrode electrochemical cell and operated in an amperometric mode, exhibiting good responses to the 50 to 500 ppb Cr(VI). Our best result from pH 3 Mcilvane’s buffer solution reveals the sensitivity of 9.12x10^-4 ppb^-1 and a detection limit of 6 ppb with no signal interference from 200 ppm Ca(II), 150 ppm Mg(II), and 50 ppb Pb(II). The excellent results of the TiO₂-rGO sensor can be attributed to synergic effects between TiO₂ and rGO, resulting from the presence of n-p heterojunctions and the formation of the TiO₂ nanoparticles on rGO.

The thermal conductivity of diamond particles reinforced copper matrix  composite as an attractive thermal management material is significantly lowered by the non-wetting heterointerface. The paper investigates the heat transport behavior between a 200 nm Cu layer and a single-crystalline diamond substrate inserted by a chromium (Cr) interlayer having a series of thicknesses from 150 nm down to 5 nm. The purpose is to detect the impact of the modifying interlayer thickness on the interfacial thermal conductance (h) between Cu and diamond. The time-domain thermoreflectance measurements suggest that the introduction of Cr interlayer dramatically improves the h between Cu and diamond owing to the enhanced interfacial adhesion and bridged dissimilar phonon states between Cu and diamond. The h value exhibits a decreasing trend as the Cr interlayer becomes thicker because of the increase in thermal resistance of Cr interlayer. The high h values are observed for the Cr interlayer thicknesses below 21 nm since phononic transport channel dominates the thermal conduction in the ultrathin Cr layer. The findings provide a way to tune the thermal conduction across the metal/nonmetal heterogeneous interface, which plays a pivotal role in designing materials and devices for thermal management applications.

The chemical composition of vanadium slag significantly affects its element distribution and phase composition, which affect the subsequent calcification roasting process and vanadium recovery. In this work, seven kinds of vanadium slags derived from different regions in China were used as the raw materials to study the effects of different components on the vanadium slag’s micromorphology, phase composition, calcification roasting, and leaching rate of major elements using SEM, XRD, and ICP-AES. The results showed that the spinel phase was wrapped with silicate phase in all vanadium slag samples. The main elements in the spinel phase were Cr, V, and Ti from the interior to the exterior. The size of spinel phase in low chromium vanadium slag was larger than other vanadium slags with higher chromium contents. The spinel phase of high-calcium and high-phosphorus vanadium slag was more dispersed. The strongest diffraction peak of vanadium spinel phase in vanadium slag migrated to a higher diffraction angle, and (Fe_0.6Cr_0.4)₂O₃ was formed after calcification roasting as the chromium content increased. A large amount of Ca₂SiO₄ was produced because excess Ca reacted with Si in high-calcium and high-phosphorus vanadium slag. The vanadium leaching rates reached 88% in some vanadium slags. The chromium leaching rates were less than 5% in all vanadium slags. The silicon leaching rate in high-calcium and high-phosphorus vanadium slag was much higher than other slags. The leaching rates of manganese were higher than 10%, and the leaching rate of iron and titanium were negligible.

Nanomaterials have been widely applied to many fields because of their excellent photocatalytic performance. The performance is closely related to the catalytic kinetics, but it is not completely clear that the influencing regularities of shape and particle size on the photocatalytic kinetics of nanomaterials and the photocatalytic kinetic mechanism. In this paper, nano-CeO₂ with different shapes and particle sizes were prepared, the kinetic parameters of adsorption and photocatalytic degradation were determined, and the effects of shape and particle size on the kinetics of adsorption and photocatalysis and photocatalytic mechanism were discussed. The results show that the shape and particle size have significant influences. With the decreases of diameter, the performances of adsorption and photocatalysis of nano-CeO₂ are improved; and these performances of spherical nano-CeO₂ are greater than those of linear nano-CeO₂. The shape and particle size have no effects on the kinetic order and mechanism of the whole photocatalytic process. Then a generalized mechanism of photocatalytic kinetics of nanomaterials was proposed and the mechanism rate equation was derived. Finally, the conclusion can be drawn: the desorption of photodegradation products is the control step of photocatalytic kinetics, and the kinetic order of photocatalytic degradation reaction is 1. The mechanism is universal and all nanomaterials have the same photocatalytic kinetic mechanism and order.

ZrC and ZrB₂ are both typical ultra-high temperature ceramics, which can be used in hyperthermal environment. In this study, a method for preparing ultrafine ZrC-ZrB₂ composite powder is provided, by using the raw materials of nano ZrO₂, carbon black, B₄C, and metallic Ca. It is worth pointing out that ZrC-ZrB₂ composite powder with any proportion of ZrC to ZrB₂ could be synthesized by this method. Firstly, a mixture of ZrC and C is prepared by carbothermal reduction of ZrO₂. By adjusting the addition amount of B₄C, ZrC is boronized by B₄C to generate ZrC-ZrB₂ composite powder with different compositions. Using this method, five composition powders with different molar ratios (100ZrC, 75ZrC-25ZrB₂, 50ZrC-50ZrB₂, 25ZrC-75ZrB₂, and 100ZrB₂) are prepared. When the temperature of boronization and decarburization process is 1473 K, the particle size of product is only tens of nanometres. Finally, the oxidation characteristics of different composite powders are investigated through oxidation experiments. The oxidation resistance of ZrC-ZrB₂ composite powder continues to increase as the content of ZrB₂ increased.

The low cell voltage during electrolytic Mn from the MnCl₂ system can effectively reduce the power consumption. In this work, the Ti/ Sn-Ru-Co-Zr modified anodes were obtained by using thermal decomposition oxidation. The physical parameters of coatings were observed by SEM. Based on the electrochemical performance and SEM/XRD of the coatings, the influences of Zr on electrode performance were studied and analyzed. When the mole ratio of Sn-Ru-Co-Zr = 6:1:0.8:0.3, the cracks on the surface of coatings were the smallest, and the compactness was the best due to the excellent filling effect of ZrO₂ nanoparticles. Moreover, the electrode prepared under this condition had the lowest mass transfer resistance and high chloride evolution activity in the 1M NH₄Cl + 1.5M HCl system. The service life of 3102 h was achieved according to the empirical formula of accelerated-life-test of the new type anode.

The effect of CaCO₃, Na₂CO₃ and CaF₂ on the reduction roasting-magnetic separation of high-phosphorus iron ore containing phosphorus as Fe₃PO₇ and apatite was investigated. The result shows that Na₂CO₃ had the best effect on iron recovery and dephosphorization, followed by CaCO₃, while CaF₂ had almost no influence. The mechanism of CaCO₃, Na₂CO₃ and CaF₂ was studied by XRD and SEM-EDS. It turns out that Fe₃PO₇ was reduced to elemental phosphorus and formed iron phosphorus alloy with metallic iron without additives. The addition of CaCO₃ reacted with Fe₃PO₇ to generate massive Ca₃(PO₄)₂ and promoted the reduction of iron oxides, however, the growth of iron particles was inhibited. After adding Na₂CO₃, the phosphorus in Fe₃PO₇ was transferred to nepheline and Na₂CO₃ improved the reduction of iron oxides and the growth of iron particles, therefore, the recovery of iron and the separation of iron and phosphorus achieved the best. CaF₂ reacted with Fe₃PO₇ to form fine Ca₃(PO₄)₂ particles scattered around the iron particles, which made the separation of iron and phosphorus difficult.

The effects of trace yttrium (Y) element on the microstructure, mechanical properties, and corrosion resistance of Mg-2Zn-0.3Ca-0.1Mn-xY (x=0, 0.1, 0.2, 0.3) biological magnesium alloys are investigated. Results show that grain size decreases from 310μm to 144μm when the Y content increases from 0 wt.% to 0.3 wt.%. At the same time, the volume fraction of the second phase increases from 0.4% to 6.0%, the yield strength of the alloy continues to increase, and the ultimate tensile strength and elongation decrease initially and then increase. When the Y content element increases to 0.3 wt.%, Mg₃Zn₆Y phase begins to precipitate in the alloy; thus, the alloy exhibits the most excellent mechanical property. At this time, its ultimate tensile strength, yield strength, and elongation are 119MPa, 69MPa, and 9.1%, respectively. In addition, when the Y content is 0.3 wt.%, the alloy shows the best corrosion resistance in the simulated body fluid (SBF). This investigation has revealed that the improvement of mechanical properties and corrosion resistance is mainly attributed to the grain refinement and the precipitated Mg₃Zn₆Y phase.

TiAl alloy with high Nb content, nominally Ti-45Al-10Nb, was prepared by powder metallurgy, and the oxidation resistance at 850, 900, and 950℃ was investigated. The high-temperature oxidation-resistance mechanism and oxidation dynamics were discussed following the oxide skin morphology and microstructural evolution analysis. The oxide skin structures were similar for 850 and 900℃, with TiO₂+Al₂O₃ mixture covering TiO₂ with dispersed Nb₂O₅. At 950℃, the oxide skin was divided into four sublayers, from the outside to the parent metal: loose TiO₂+Al₂O₃, dense Al₂O₃, dense TiO₂+Nb₂O₅, and TiO₂ matrix with dispersed Nb₂O₅. The Nb layer suppressed the outward diffusion of Ti atoms, hindering the growth of TiO₂, and simultaneously promote the formation of a continuous Al₂O₃ protective layer, providing the alloy with long-term high-temperature oxidation resistance.

Reverse flotation desilication has been an indispensable step for obtaining high-grade fluorapatite. In this work, Dodecyl Trimethyl Ammonium Bromide (DTAB) was recommended as an efficient collector for the reverse flotation separation of quartz from fluorapatite. Its collectivity for quartz and selectivity for fluorapatite were also compared with the figures corresponding to the conventional collector dodecylamine hydrochloride (DAC) via micro-flotation experiments. The adsorption behaviors of both DTAB and DAC on minerals were systematically investigated with surface chemical analyses such as contact angle determination, zeta potential detection, and adsorption density measurement. It was revealed that compared to DAC, DTAB displayed similar and strong collectivity for quartz, while it showed a better selectivity (or worse collectivity) for fluorapatite, resulting in a high-efficiency for the separation of the two minerals. Surface chemical analyses showed that the adsorption ability of DTAB on quartz surface was as strong as DAC, while the adsorption amount of DTAB on fluorapatite surface was much lower than that of DAC, which associated to the flotation performance well. During the floatation separation of the actual ore, 8% fluorapatite with higher grade can be obtained by using DTAB in contrast to DAC. Therefore, DTAB is a promising collector to the high-efficiency purification and sustainable utilization of the valuable fluorapatite recourses.

Laser shock peening (LSP) is an attractive post-processing method to tailor surface microstructure and enhance mechanical performances of additive manufactured (AM) components. The effects of multiple LSP impacts on the microstructure and mechanical properties of Ti-6Al-4V part produced by electron beam melting (EBM), as a mature AM process, were studied in this work. Microstructure, surface topography, residual stress and tensile performance of EBM-manufactured Ti-6Al-4V specimens were systematically analyzed subjected to different LSP impacts. The distribution of porosities in EBM sample was assessed via X-ray computed tomography. The results show that EBM samples with two LSP impacts possess a lower porosity value of 0.05% compared to the value of 0.08% for untreated samples. The strength of EBM samples with two LSP impacts is remarkably raised by 12% as compared with the as-built samples. The grains of α phase is refined in near-surface layer and a dramatic increase in the depth and magnitude of compressive residual stress (CRS) is achieved in EBM sample with multiple LSP treatments. The grain refinement of α phase and CRS with larger depth are responsible for the strength enhancement of EBM samples with two LSP impacts.

With 3C industries developing rapidly, the demand for high-thermal-conductivity magnesium alloy with high mechanical performance is increasing rapidly. However, the thermal conductivities of most common Mg foundry alloys (such as Mg-9wt.%-1wt%Zn) are still relativity low. In the present study, we developed a high-thermal-conductivity Mg-4Al-4Zn-4RE-1Ca (wt.%, AZEX4441) alloy with good mechanical properties for ultrathin-walled cellphone components via high pressure die casting (HPDC). The HPDC AZEX4441 alloy exhibited a fine homogeneous microstructure (the average grain size is 2.8 μm) with granular Al₁₁RE₃, fibrous Al₂REZn₂, and networked Ca₆Mg₂Zn₃ phases distributed at the grain boundaries. The room-temperature thermal conductivity of the HPDC AZEX4441 alloy was 94.4 W/(m·K), which was much higher than 53.7 W/(m·K) of the HPDC AZ91D alloy. The Al and Zn elements of the AZEX4441 alloy were largely consumed by the formation of Al₁₁RE₃ and Al₂REZn₂ as well as Ca₂Mg₆Zn₃ phases due to the addition of RE and Ca. Therefore, the lattice distortion induced by solute atoms of the AZEX4441 alloy (0.171%) was much lower than that of AZ91D alloy (0.441%), which was responsible for the high thermal conductivity of the AZEX4441 alloy. Furthermore, the AZEX4441 alloy exhibited a high yield strength (YS) of ~185 MPa, ultimate tensile strength (UTS) of ~233 MPa, and elongation of ~4.2%, indicating comparable tensile properties to AZ91D alloy. The results will contribute to developing high-performance Mg alloys with a combination of high thermal conductivity, high strength, and good castability.

An excellent organolead halide perovskite film plays an important role for good-performance perovskite solar cells (PSCs), while there are many defects at perovskite crystals, which is bad for both the photovoltaic properties and the stability of solar cells. Therefore, a strategy of incorporating a complex of CdS and Cd(SCN₂H₄)₂Cl₂ into CH₃NH₃PbI₃ active layer is proposed to solve this problem. This study systematically analyzes the effect of different doping concentration of CdS and Cd(SCN₂H₄)₂Cl₂ on the performance and stability of PSCs. Our results find that an appropriate incorporation concentration of CdS and Cd(SCN₂H₄)₂Cl₂ doped in CH₃NH₃PbI₃ can improve the performance of the prepared solar cells, which is mainly due to that the CdS and Cd(SCN₂H₄)₂Cl₂ can effectively passivate the defects at perovskite crystals, thereby suppressing the charge recombination in PSCs and promoting the charge extraction at TiO₂/perovskite interface. Furthermore, the stability of PSCs is also significantly improved due to the reduced perovskite crystal defects and enhanced compactness of the C:C:CH₃NH₃PbI₃ composite film. 

Since the physical and chemical properties of apatite and dolomite can be similar, the separation of these two minerals is difficult. Therefore, when performing this separation using the flotation method, it is necessary to search for selective depressants. An experimental research was performed on the separation behavior of apatite and dolomite using calcium lignosulfonate as a depressant, and the mechanism by which this occurs was analyzed. The results show that calcium lignosulfonate has a depressant effect on both apatite and dolomite, but the depressant effect on dolomite is stronger at the same dosage. Mechanism analysis shows that the adsorptive capacity of calcium lignosulfonate on dolomite is higher than that of apatite, which is due to the strong reaction between calcium lignosulfonate and the Ca sites on dolomite. In addition, there is a hydrogen bond between calcium lignosulfonate and dolomite, which further prevents the adsorption of sodium oleate to dolomite, thus greatly inhibiting the flotation of dolomite.

The oxidation behaviors of three austenitic cast steels with different morphology of primary carbides at 950°C in air was investigated using SEM, EDS, XRD and FIB/TEM. It was found that their oxidation kinetics followed a logarithmic law and the oxidation rate could be significantly decreased as long as a continuous silica layer formed at the scale/substrate interface. When the local Si concentration was inadequate, the internal oxidation beneath the oxide scale occurred. The spallation of oxides during cooling could be inhibited with the formation of internal oxidation, owing to the reduced mismatch stress between the oxide scale and the substrate. The "Chinese-script" primary Nb(C,N) was superior to the dispersed primary Nb(C,N) in suppressing the oxidation penetration in the interdendritic region by supplying a high density of Cr quick-diffusion channels. In addition, the innermost and the outermost oxidation layers were both found to be enriched with Cr, while the Cr evaporation in the outermost layer was significant when the water-vapor concentration in the environment was high enough. These findings further the understanding regarding the oxidation behavior of austenitic cast steels and will promote the alloy development for exhaust components.

Since ultraviolet (UV) light, as well as blue light, which was part of visible light, was harmful to skin, samarium-cerium compounds containing Sm₂O₂S were synthesized by co-precipitation method. This kind of compounds blocks not only UV light, but also blue light that is part of visible light. The minimum values of average transmittance (360–450 nm) and band gap of samarium-cerium compounds were 8.90% and 2.30 eV, respectively, which were less than 13.96% and 2.63 eV of CeO₂. Elemental analysis (EA), X-ray diffraction (XRD), Fourier transformation infrared (FT-IR), and Raman spectra determined that the samples contained Ce₄O₇, Sm₂O₂S, Sm₂O₃, and Sm₂O₂SO₄. The micro-structure of samples was analyzed by scanning and transmission electron microscopy (SEM, TEM). X-ray photoelectron spectrum (XPS) showed cerium had Ce³⁺ and Ce⁴⁺ valence states, and oxygen was divided into lattice oxygen and oxygen vacancy that was direct cause of the decrease of average transmittance and band gap.

This study investigates hydrochar combustion kinetics using a multi-Gaussian-distributed activation energy model (DAEM) to expand knowledge on combustion mechanisms. The results demonstrate that the kinetic parameters calculated by the multi-Gaussian-DAEM accurately represented the experimental conversion rate curves. Overall, the feedstock combustion could be divided into four stages: the decomposition of hemicellulose, cellulose, lignin, and char combustion. The hydrochar combustion could in turn be divided into three stages: the combustion of cellulose, lignin, and char. The mean activation energy ranges obtained for the cellulose, lignin, and char of the hydrochar were 273.7–292.8, 301.6–334.5, and 355.2–365.1 kJ/mol, respectively, with standard deviations of 2.1–23.1, 9.5–27.4, and 12.1–22.9 kJ/mol, respectively. The cellulose and lignin contents first increased and then decreased with increasing hydrothermal carbonization (HTC) temperature, while the mass fraction of char gradually increased.

Ni-based composite coatings incorporated with nano/micron SiC particles were fabricated via electrochemical co-deposition in Watts bath, followed by the evaluation of their mechanical and anti-corrosion properties. The micrographic observations suggest that the SiC particles with various sizes can be well incorporated to the Ni substrate. X-ray diffraction (XRD) patterns indicate that SiC particles with smaller sizes could weaken the preferential growth of Ni along (2 0 0) facet. In addition, it is found that the incorporated SiC particles with medium micron sizes (8 μm and 1.5 μm) could significantly enhance the micro-hardness of the Ni composite coatings. Nevertheless, electrochemical measurements demonstrate that micron-sized SiC particles would weaken the corrosion resistance of Ni composite coatings ascribed to the structure defects induced. In contrast, the combined incorporation of nanosized (50 nm) SiC particles with medium micron (1.5 μm) ones is capable of promoting the compactness of the composite coatings, which is beneficial to the long-term corrosion resistance with negligible micro-hardness loss.

The effect of Al₂O₃ on the viscosity and structure of CaO–SiO₂–Cr₂O₃–Al₂O₃ slags is investigated to facilitate recycling of Cr in steelmaking slags. The slags exhibit good Newtonian behavior at high temperature. The viscosity of acidic slag first increases from 0.825 to 1.141 Pa·s as the Al₂O₃ content increases from 0 to 10wt% and then decreases to 1.071 Pa·s as the Al₂O₃ content increases further to 15wt%. The viscosity of basic slag first increases from 0.084 to 0.158 Pa·s as the Al₂O₃ content increases from 0 to 15wt% and then decreases to 0.135 Pa·s as the Al₂O₃ content increases further to 20wt%. Furthermore, Cr₂O₃-containing slag requires less Al₂O₃ to reach the maximum viscosity than Cr₂O₃-free slag; the Al₂O₃ contents at which the behavior changes are 10wt% and 15wt% for acidic and basic slags, respectively. The activation energy of the slags is consistent with the viscosity results. Raman spectra demonstrate that [AlO₄] tetrahedra appear initially and are replaced by [AlO₆] octahedra with further addition of Al₂O₃. The dissolved organic phosphorus content of the slag first increases and then decreases with increasing Al₂O₃ content, which is consistent with the viscosity and Raman results.

The study explores the excellent modification effect of Nb nanocatalyst prepared via surfactant assisted ball milling technique (SABM) on the hydrogen storage properties of MgH₂. Optimal catalyst doping concentration was determined by comparing onset decomposition temperature, released hydrogen capacity and reaction rate for different MgH₂+ywt% Nb (y = 0, 3, 5, 7, 9) composites. The MgH₂+5wt% Nb composite started releasing hydrogen at 186.7℃ and a total of 7.0wt% hydrogen was released in the dehydrogenation process. In addition, 5wt% Nb doped MgH₂ also managed to release 4.2wt% H₂ within 14 minutes at 250℃ and had the ability to absorb 4.0wt% hydrogen in 30 minutes at 100℃. Cycling tests revealed that MgH₂+5wt% Nb could retain 6.3 wt% H₂ capacity (89.2%) after 20 cycles. Dehydrogenation and hydrogenation activation energy values were decreased from 140.51±4.74 kJ·mol^-1 and 70.67±2.07 kJ·mol^-1 to 90.04±2.83 kJ·mol^-1 and 53.46±3.33 kJ·mol^-1 after doping MgH₂ with Nb, respectively. Microstructure analysis proved that homogeneously distributed NbH acted as active catalytic unit for improving the hydrogen storage performance of MgH₂. These results indicate SABM can be considered as an option to develop other nanocatalysts for energy related areas.

The interfacial phenomena in mold have great impact on the smooth operation and the quality of the casting product. In this paper, the wetting behavior of CaO-Al₂O₃-based mold flux with different BaO and MgO contents was studied. The results show that the contact angle between molten flux and IF steel substrate increased from 62.4^o to 74.5^o with the increase of BaO content from 3wt% to 7wt%, while it decreased from 62.4^o to 51.3^o with the increase of MgO content from 3wt% to 7wt%. The interfacial tension also increased from 1630.3 to 1740.8 mN/m when the BaO content increased, but it reduced from 1630.3 to 1539.7 mN/m with the addition of MgO. The changes of contact angle and interfacial tension were mainly due to the fact that the bridging oxygen (O⁰) at the interface was broken into non-bridging oxygen (O^-) and free oxygen (O^2-) by MgO. However, more O^- and O^2- connected into O⁰ when BaO was added, since the charge compensation effect of BaO was so stronger that it offset the effect of providing O²⁻.

The effective recycling of waste printed circuit boards (WPCBs) can conserve resources and reduce environmental pollution. This study explores the pyrolysis and combustion characteristics of WPCBs in various atmospheres through thermogravimetric and Gaussian fitting analyses. Furthermore, this study analyses the pyrolysis products and combustion processes of WPCBs through thermogravimetric–Fourier transform infrared and thermogravimetric–mass spectrometry analytical techniques. Results show that the pyrolysis and combustion processes of WPCBs do not constitute a single reaction, but rather, they constitute an overlap of multiple reactions. The pyrolysis and combustion process of WPCBs is divided into multiple reactions by Gaussian peak fitting, and the kinetic parameters of each reaction are obtained by the Coats-Redfern method. In an argon atmosphere, pyrolysis consists of the overlap of the preliminary pyrolysis of epoxy resin, pyrolysis of small organic molecules, and pyrolysis of brominated flame retardants. The reaction mechanism functions are G(α)= (1-α)^-1-1, G(α) = (1-α)^-1-1 and G(α)= [-(1-α)]⁴ (α is the conversion rate of the reaction,  G(α) is the mechanism function of the reaction). The combustion of WPCB in oxygen consists of the overlap of the epoxy resin and brominated flame retardant combustion reactions; the reaction mechanism functions are G(α)= ((1-α)^-1/3-1)² and G(α)= ((1-α)^-1/3-1)². This study provided the theoretical basis for pollution control, process optimization and reactor design of WPCBs pyrolysis.

The effect of Al content (0.035, 0.5, 1 and 2 wt%) on the composition change of steel and slag, as well as inclusion transformation of high manganese steel after equilibrated with CaO-SiO₂-Al₂O₃-MgO slag was studied by method of slag/steel reaction. The experimental results show that, as the initial content of Al increased from 0.035% to 2%, Al gradually replaced Mn to react with SiO₂ in slag to avoid the loss of Mn due to the reaction, which caused both Al₂O₃ in slag and Si in steel to increase, while SiO₂ and MnO in slag to reduce. In addition, the type of inclusions also evolved as the initial Al content increased. The evolution route of inclusions was MnO→MnO-Al₂O₃-MgO→MgO→MnO-CaO-Al₂O₃-MgO and MnO-CaO-MgO. The shape of inclusions evolved from spherical to irregular, faceted, and finally transformed to spherical. The average size of inclusions presented a trend that was increasing first and then decreasing. The transformation mechanism of inclusions was explored. As the initial content of Al increased, Mg and Ca were reduced from top slag into molten steel in sequence, which consequently caused the transformation of inclusions.

Ni-rich layered material is a kind of high-capacity cathode to meet the requirement of electric vehicles. As for the typical LiNi_0.8Co_0.1Mn_0.1O₂ material, the particle formation is significant for electrochemical properties of the cathode. In this work, the structure, morphology and electrochemical performance of LiNi_0.8Co_0.1Mn_0.1O₂ secondary particles and single crystals are systematically studied. A lower Ni²⁺/Ni³⁺ ratio of 0.66 and a lower residual alkali content of 2280 ppm were achieved on the surface of single crystals. In addition, the single crystals showed a discharge capacity of 191.6 mAh/g at 0.2 C (~12 mAh/g lower than that of the secondary particles) and enhanced electrochemical stability, especially when cycled at 50 °C and in a wider electrochemical window (between 3.0 and 4.4 V vs. Li+/Li). The LiNi_0.8Co_0.1Mn_0.1O₂ secondary particles were suitable for applications requiring high specific capacity, whereas single crystals exhibited better stability, indicating that they are more suitable for use in long life requested devices.

Mg alloy casting parts commonly suffer from drawbacks of low surface properties, high susceptibility to corrosion, unsatisfactory absolute strength, and poor ductility, which seriously limit their wide application. Here, a surface nanocrystallization technique, i.e., ultrasonic surface rolling (USR), was applied on an as-cast AZ91 Mg alloy sheet to improve its corrosion resistance and mechanical properties. The USR produces double smooth surfaces with R_a=0.026 μm and gradient nanostructured surface layers on the sheet. Due to this special microstructure modification, the USR sheet exhibits 51% and 50% improvements in tensile yield strength and ultimate strength without visibly sacrificed ductility comparable to its untreated counterpart, as well as a 24% improvement in surface hardness. The USR sheet also shows good corrosion resistance in 3.5% NaCl aqueous solution. The corrosion current density of the USR sheet reduces by 63% after immersion for 1 h, and 25% after immersion for 24 h compared to that of the untreated counterpart. The enhanced strength and hardness are mainly related to the gradient nanostructure. The improved corrosion resistance is mainly ascribed to the decreased surface roughness, nanostructured surface, and residual compressive stress. The present results state that USR is an effective and attractive method to improve multiple properties of Mg alloy casting parts, and thus can be used as an additional and last working procedure to achieve high-performance Mg alloy casting parts.

Duplex stainless steels (DSSs) are suffering from various localized corrosion attacks such as pitting, selective dissolution, crevice corrosion during their service period. It is of great value to quantitatively analyze and grasp the micro-electrochemical corrosion behavior and related mechanism for DSSs on the micrometer or even smaller scales. In this work, scanning Kelvin probe force microscopy (SKPFM) and energy dispersive spectroscopy (EDS) measurements were performed to reveal the difference between the austenite phase and ferrite phase in microregion of DSS 2205. Then traditional electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) tests were employed for micro-electrochemical characterization of DSS 2205 with different proportion phases in Φ40 μm and Φ10 μm micro holes. Both of them can only be utilized for qualitative or semi-quantitative micro-electrochemical characterization of DSS 2205. Coulostatic perturbation method was employed for quantitative micro-electrochemical characterization of DSS 2205. What is more, the applicable conditions of coulostatic perturbation were analyzed in depth by establishing a detailed electrochemical interface circuit. A series of microregion coulostatic perturbations for DSS 2205 with different proportion phases in Φ10 μm micro holes showed that as the austenite proportion increases, the corresponding polarization resistance of microregion increases linearly.

An energy-efficient route was adopted to treat titanium-bearing blast furnace slag (TBBFS) in this study. Titanium, aluminum and magnesium were simultaneously extracted and silicon was separated by sulfuric acid curing in low temperature and low concentration sulfuric acid leaching. The process parameters of sulfuric acid curing TBBFS were systematically studied. Under the optimal conditions, the recovery of titanium, aluminum and magnesium reached 85.96%, 81.17% and 93.82%, respectively. The rapid leaching model was used to limit the dissolution and polymerization of silicon, and the dissolution of silicon was only 3.18%. The mechanism of sulfuric acid curing-leaching was investigated. During the curing process, the reaction occurred rapidly and released heat massively. Under the attack of hydrogen ions, the structure of TBBFS was destroyed, silicate was depolymerized to form filterable silica, and titanium, magnesium, aluminum, and calcium ions were replaced to form sulfates and enriched on the surface of silica particles. Titanium, aluminum, and magnesium were recovered in the leaching solution, and calcium sulfate and silica were enriched in the residue after leaching. This method could effectively avoid the formation of silica sol during the leaching process and accelerate the solid-liquid separation.

Porous materials have many promising prospects in such fields as sound insulation, heat barrier, vibration attenuation, and catalysts, due to their special porous structures. Most of the industrial solid wastes such as tailings, coal gangue, and fly ash are rich in silicon. As far as this is concerned. In this regard, the high silicon content makes it a potential raw material for the synthesis of silicon-based multi-porous materials such as zeolites, mesoporous silica, glass ceramics, geopolymer foams, etc. In this mini review, the representative silicon-rich industrial solid wastes (SRISW) are selected as the objects, which focused on the processing and application of silicon porous materials from the aspects of physical and chemical properties of SRISW. The transformation methods of preparing porous materials from silicon rich industrial solid wastes are summarized, and their research status in micro-, meso-, and macro-scale porous materials are concluded, respectively. Also the possible problems existing in the application of silicon-rich industrial solid wastes, and in the preparation of functional porous materials are analyzed, and their developing orientation is prospected. This review should provide a typical reference for the recycling and utilization of industrial solid wastes to develop some sustainable “green materials”.

Current electronic technology based on silicon is approaching to its physical and scientific limits. When facing the compulsory choice of finding a practicable way of potential material alternatives for next generation electronics, carbon-based devices showing numerous superiorities (e.g., fast speed, low power consumption and simple process) combining with the unique nature of versatile allotropes of carbon element are unfolding the promise of upcoming electronics revolution. Now it is the time that carbon electronics are greatly advancing with not only developed preparation but also sophisticated design. In this perspective, the representatives with various dimensions, e.g., carbon nanotubes, graphene, bulk diamond, together with extraordinary performance are reviewed. Based on these members of carbon materials family, the associated state-of-the-art devices and composite hybrid all-carbon structures are also emphasized to embody their inherent dominances in the electronics field. Advances of commercial production with improved cost-efficiency and material quality as well as devices design are ongoingly accelerating to the bright future, and it is virtually even impossible to keep up with this burgeoning situation.

Applying an external field has been known to be a promising method to control the microstructure of materials, leading to their improved performance. In the present paper, the strengthening and toughening behaviors of some typical high-performance structural materials by coupling multi-physics fields, including electrostatic or electric-pulse, thermal, and stress fields, are reviewed in detail. In addition to the general observation that the plasticity of materials could be increased by multi external fields, their strengthening can also be achieved through controlling atomic diffusion or phase transformations. The paper is not limited to the strengthening and toughening mechanisms of the multi-field coupling effects on different types of structural materials, but is intended to provide a generic method to improve both the strength and ductility of the materials. Finally, future prospects about applications of multi external field have also been put forward based on the current works.

Diamond/metal composites are widely used in national defense technology and national production due to their outstanding properties of high thermal conductivity and low expansion. However, the difference of chemical properties leads to the interface incompatibility between diamond and metal, which has an important impact on the properties of the composites. Interfacial modification is an effective way to improve the interfacial bonding and reduce the interfacial thermal resistance. This paper reviews the experimental research on interface modification of diamond/metal composites and the application of material calculation simulation in diamond/metal composites. Combining computational simulation and experiment is an expected method to advance the research of diamond/metal composite interface modification.

Metal halide perovskite solar cells have caused great attention due to their high power conversion efficiency (PCE) and cost-effective solution-processable fabrication, but suffer from poor structure stability. Two-dimensional (2D) Ruddlesden-Popper (RP) metal halide perovskites could address the above issue and possess excellent stability because of the large organic spacer cation around the halide octahedron of perovskites. However, the crystallographic orientation of 2D crystals should be perpendicular to the bottom substrates for realizing fast charge transport and collection of the solar cells.  It is still a great challenge to control the crystallographic orientation of the 2D RP perovskites prepared by the solution process. Herein, we reviewed the recent progress of the 2D RP perovskite films with the focus on the crystallographic orientation mechanism and orientation controlling methods. Furthermore, the current issues and prospects of the 2D RP perovskites in the photovoltaic field were also discussed, aiming to shed light on developing and widely applying them in the near future.

High hydrogen absorption and desorption rates are two of significant index parameters for the applications of hydrogen storage tanks. Analysis of the hydrogen absorption and desorption behaviours by the isothermal kinetic models is an efficient way to investigate the kinetic mechanism. Multitudinous kinetic models have been developed to describe the kinetic processes. However, these kinetic models were deduced based on some assumptions and only appropriate for the specific kinetic measurement methods and rate-controlling steps, which is sometimes confusing for application. The kinetic analysis procedures using those kinetic models, as well as the key kinetic parameters, are not clear for many researchers who do not become familiar with this field. These problems will prevent kinetic models and their analysis methods from revealing the kinetic mechanism of hydrogen storage alloys. Thus, this review mainly focuses on the summarisation of the kinetic models based on the different kinetic measurement methods and rate-controlling steps, and the introduction of the analysis procedures and the applications of kinetic models in metal hydrides.

Selective laser melting (SLM), an additive manufacturing (AM) process mostly applied in metal material field, can fabricate complex shaped metal objects with high precision. Nickel-based superalloy possesses excellent mechanical property at elevated temperature and plays an important role in aviation industry. This paper emphasizes the researches of SLM processed Inconel 718, Inconel 625, CM247LC and Hastelloy X which are typical alloys with different strengthening mechanism and operating temperature. The strengthening mechanism and phase change evolution of different Nickel-based superalloy under laser irradiation are discussed. The influence of laser parameter and heat-treatment process on mechanical properties of SLM Nickel-based superalloy are systematically introduced. Moreover, the attractive industrial applications of SLM Nickel-based superalloy and printed components are presented. At last, the development of Nickel-based superalloy materials for SLM technology is prospected.

Considering the valuable compositions and potential environmental hazardousness of titanium-bearing blast furnace slag (BFS), developing efficient and green approaches to utilization of BFS is highly desired for resource economization and environmental protection. In the past decades, many attempts have been adopted to efficiently reuse BFS, and significant advances in understanding the fundamental features and the development of efficient approaches have been made. In this review, we have provided a comprehensive overview of the latest progress on efficient utilization BFS, and discussed the mechanism and characteristics of various approaches, along with their application prospects. In particular, the approaches of extraction and enrichment of titanium-bearing phases from BFS are highlighted due to their high availability of titanium resources. This systemic and comprehensive review may benefit to design new and green utilization route with high efficiency and low cost.