The effect of solid state diffusion of Li on the polarization behavior of Li-Al alloy anode was studied, and Li-Al electrodes with different specific surface areas and Cu@Li electrodes without the effect of solid state diffusion of Li were prepared. The polarization behavior of electrodeposited Li-Al alloy with a deposited capacity of 0.51 mAh/cm² in a half cell and a full cell were investigated by using galvanostatic charge-discharge measurement, cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and galvanostatic intermittent titration technique. The results show that the solid-state diffusion of Li in Li-Al is the main reason for the polarization of Li-Al electrode in a half cell and a full cell, and the diffusional lithium trapping will increase the internal resistance of the cell, bringing in enhanced polarization phenomenon and finally resulting in the low discharge potential of about 1.84 and 1.55 V for Li-Al‖S battery. Surface α-Al layer causes diffusional lithium trapping, and disrupting it can not only increase the Li⁺ concentration in the electrolyte and promote the precipitation of Li₂S, leading to reduced polarization, but also increase discharge voltage of LiAl‖S battery to approach the thermodynamic discharge potential.

In order to scientifically assess risks in the production and operation of underground mines and improve the safety prevention and control in underground mining, a risk assessment index system for underground mines was constructed by selecting five primary indices and 16 secondary indices based on the underground mining characteristics. And then, the subjective and objective weights of the assessment indices were determined by using analytic hierarchy process (AHP) and entropy weight method (EWM), and the comprehensive weight of the indices was also optimized by adopting a combined weighting method to improve the accuracy of the assessment results. The safety risk in underground mines was assessed with the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Later, five mines investigated by the experts organized by Hunan Bureau of the State Administration of Mine Safety were taken as samples for assessment with this method. The safety risk assessment results obtained with different models show that three risk indices with higher weights, including operation status of six equipment systems in terms of equipment factor, mine geological conditions in terms of environmental factor, and work safety system in terms of management factor, can bring obvious threat to the mine safety operation. The safety risk assessment of five mines shows that a tungsten mine has the highest risk level, while a graphite mine has the lowest risk level.

Vanadium slag, as raw material, went through calcified roasting processes in the study, and the thermodynamics and kinetic analysis were conducted for verifying the roasting mechanism. The results show that calcified roasting process mainly includes iron oxidation, oxidative decomposition of olivine and spinel, as well as calcification. Based on theoretical and data analysis, calcium-containing phases are formed in the following sequence: CaV₂O₆, Ca₂V₂O₇, Ca₃V₂O₈, CaSiO₃. At a high temperature, excess CaO reacts with vanadium to generate Ca₃V₂O₈ and CaSiO₃. The oxidation and calcification processes of vanadium spinel are controlled by a third-order reaction, and the apparent activation energy is 282.45 kJ/mol. In the leaching experiment, the leaching rate reaches the maximum after roasting at 860 ℃ for 120 min, which is consistent with the results obtained from theoretical analysis of calcified roasting process.

In order to conduct more practical stability analysis for soil-rock slope, it was proposed to use Fortran language in a slope model to randomly generate rocks, based on which a soil-rock slope model was established. The stability analysis was conducted respectively for soil-rock slopes with five kinds of rock content. It is found that as the rock content therein increases, the slope stability gradually improves and the potential sliding surface of the slope also changes. The plastic zone penetration presents three typical modes: rock detouring, shunting and rock inclusion. The displacement in X direction is always the largest at the foot of the slope, and the maximum total displacement starts at the foot, moving to the middle of the slope and finally back to the bottom of the slope. The simulation results obtained by this method were compared to the calculation results of models with two typical equivalent strength parameters, and it is concluded that the safety factor calculated by this method is quite different from that obtained by the other two models, and also different in changing trend. In the future, this soil-rock slope model can be further optimized for other complex working conditions based on the mechanical characteristics and laws, with the influence of joints and cracks also taken into consideration.

A technique consisting of acid leaching, oxidative precipitation for impurity removal, and solvent extraction was adopted to effectively separate and recover nickel from high-nickel electroplating sludge, and then high-purity nickel sulfate hexahydrate was prepared. Firstly, the sludge was leached with sulfuric acid, and most of nickel, copper, iron and aluminum in the sludge were leached out in the leachate; then, hydrogen peroxide was added to the leachate for oxidation and precipitation to remove iron therein, and the suitable endpoint pH value was 3; after that, sodium sulfide with an appropriate excess coefficient of 1.2 was added to remove impurities therein, resulting in the precipitation rates of Fe and Cu reaching 99.43% and 98.13% respectively; by adjusting the pH value of the precipitated solution, nickel hydroxide was precipitated and then dissolved with sulfuric acid into nickel sulfate solution, which was extracted with P204 for deep removal of impurities. As a result, the secondary extraction rates of Cu, Fe and Al were up to 98.41%, 99.99% and 95.15% respectively, and the extraction rate of Ni was just 9.4%. The obtained raffinate was subjected to evaporation concentration, followed by cooling crystallization, and a nickel sulfate hexahydrate with purity exceeding 99.95% was finally prepared.

The effects of continuous and semi-continuous synthesis processes of precursor on the structure and performance of precursor materials and nickel-rich NCM cathode materials were explored. The results show that primary particles of the precursors synthesized by these two processes are quite different in morphology, leading to the difference in structure of primary/secondary particles and electrochemical property of the correspondingly synthesized cathode materials. These two cathode materials present little different performance in a button half cell, but significant difference in a soft pack battery. The nickel-rich cathode synthesized by the semi-continuous process has a lower impedance at a low state of charge, and retains 87.61% of its capacity after 750 cycles at 45 ℃, much higher than the retention rate (77.65%) of the nickel-rich cathode synthesized by the continuous process. It is concluded that the semi-continuous synthesis process for precursor is superior in the production of nickel-rich cathode materials.

CiteSpace, as a bibliometric analysis tool, was firstly used to quantitatively analyze and visualize keyword clusters, co-citation relationships and burst terms for scientific literature on Laves phase used for high-temperature materials in the Web of Science from 2003 to 2023. A timeline chart of keyword clustering reflects the fundamental development status of Laves phase research in the search interval, revealing two hot topics in frontier research: one is improvement of room temperature brittleness or synergistic improvement of strength and plasticity of multi-phase high-entropy alloys reinforced by Laves phases, another is the effect of Laves phase precipitates on the microstructure and properties of heat-resistant alloy steels (P92, 12Cr and G115) at 600-650 ℃, at which creep occurs. The timeline chart of keyword clustering is consistent with the chart of relationship between literature and author in citation networks, both reflecting the activity of Laves phase research. In the future, those key authors and publications with high-quality achievement mined by the visualized patterns and trend should be paid more attention.

ZL101 alloy was modified by using mechanical stir casting process with an addition of rare-earth Yb at the mass fraction of 0-0.9%, for investigating the effect of Yb content on the microstructure and corrosion resistance of ZL101 alloy. The results show that with the addition of rare-earth Yb at a mass fraction of 0.6%, ZL101 alloy has its α-Al phase changed from coarse dendritic structure without modification to spheroidal dendrite with fine size, regular shape and regular arrangement, also the eutectic Si phase changed from the coarse long strip and needle sheet to the granular and short rod. It is shown that Yb reacts with Al substrate to form Al₃Yb rare-earth phase with long strip structure. With the addition of Yb at 0.6%, ZL101 alloy has its corrosion rate at 13.25 mg/(cm²·d), 37.23% lower than that before the addition of Yb. It can be seen from the corrosion surface observation that increasing Yb content leads to gradual decrease in the number of corrosion products and pits on the corrosion surface of the alloy.

The innovation efficiency of each link of China's non-ferrous metal-new energy industrial chain was measured based on a four-stage DEA model, and its influencing factors were analyzed with the Tobit model. Based on the study, the following conclusions can be made: after SFA model adjustment, the four links of the industrial chain, i.e. mineral products, refined products, new energy materials and new energy application, can be arranged in descending order in terms of innovation efficiency, and pure technical efficiency is the key factor restricting the improvement of the innovation efficiency of each link of the industrial chain; the innovation efficiency of the industrial chain also presents the characteristics of being stronger in the west and weaker in the east in terms of spatial distribution; state-owned enterprises can demonstrate high innovation efficiency than non-state-owned enterprises; the concentration of suppliers, enterprise size, and the quality of employees are positively correlated to the innovation efficiency, while the degree of market competition, the debt to asset ratio, and the equity concentration are negatively correlated to the innovation efficiency. In order to improve the innovation efficiency of the industrial chain, more efforts should be made in policy support for reducing innovation risks of new energy enterprises, increasing the returns of new energy enterprises, and promoting the formation of industrial clusters.

The effects of different solid solution time on the mechanical properties, intergranular corrosion (IGC) and microstructure of an Al-Cu-Mg-Ag alloy were investigated by performing tensile testing, IGC tests, and electrochemical corrosion analysis, as well as using transmission electron microscopy, scanning electron microscopy and electron backscatter diffraction techniques. Results show that increasing the solution time from 5 min to 120 min leads to a gradual dissolution of residual second phase and a gradual increase in the size and quantity of Ω phase, contributing to a remarkable improvement in mechanical properties. Meanwhile, the IGC resistance of Al-Cu-Mg-Ag alloy is found to be considerably degraded as solution time is prolonged. The potential difference between the precipitation free zone (PFZ) and the matrix is the decisive factor in accelerating the IGC rate, while the PFZ width has no obvious influence on IGC resistance.