Lithium-ion batteries have been a crucial and indispensable energy storage system in the energy technology. Developing Li-ion batteries with high energy density，extended cycle life，and cost-effectiveness is a central challenge. Silicon material，distinguished by its impressive theoretical capacity of 4200 mAh·g^-1 and low price，has emerged as a promising candidate for negative electrode material. However，its substantial volume expansion，reaching up to 300% during charging and discharging cycles，poses a formidable commercial hurdle. To date，three generations of silicon-carbon negative electrode materials have undergone iterative development. This review focuses on three generations of silicon-carbon negative electrode materials fabricated via the CVD method. The material structure design，experimental methodologies，reaction mechanisms，and material properties are analyzed. The strengths and weaknesses of these three generations of preparation techniques are summarized，and insights into the future direction of silicon-carbon negative electrodes in Li-ion batteries are provided.

With the development of portable electronic devices and electric vehicles， the energy density of traditional lithium-ion batteries is approaching their theoretical limit. The research on lithium metal batteries with high energy density has been re-focused. However， the high reactivity of lithium increases safety risks and reduces energy density when excess lithium is used. Anode-free lithium metal batteries （AF-LMBs） have emerged as a solution. AF-LMBs possess high energy density and the lowest redox potential. But they have poor cycle life， limited active materials， and complex interfacial reactions. Improving the cycle stability of AF-LMBs is key to realizing the application of high-energy-density storage systems.This paper reviews the development of AF-LMBs and analyzes in depth the current challenges they face from four aspects： lithium dendrites， electrolyte stability， solid electrolyte interface （SEI）， and current collectors. These factors together affect the cycle stability， safety， and energy density of AF-LMBs. Finally， it is pointed out that the future research directions should focus on optimizing electrolyte formulations， designing artificial SEI layers， and improving current collector materials and structures. Meanwhile， paying attention to the volumetric energy density of batteries to meet the demand for compact and efficient energy storage systems in practical applications， thereby promoting the commercialization of AF-LMBs.

With the rapid development of modern technology，there is an increasing demand for energy storage systems that can operate stably in extreme environments，especially in cutting-edge fields such as unmanned aerial vehicles，electric vehicles，and deep-sea exploration. Lithium-ion batteries，due to their high energy density，long life，and lack of memory effect，have become an ideal choice to meet the energy needs in these extreme environments. However，harsh conditions such as extreme temperatures，impacts，and pressures pose serious challenges to the performance and safety of batteries. This article reviews the failure behaviors and mechanisms of lithium-ion batteries in various extreme environments in recent years，focusing on the changes in the internal material structure of the batteries，lithium ion transport，and electrochemical reactions to explore the internal material failure mechanisms of lithium-ion batteries under various extreme conditions. Finally，the article summarizes the main measures to improve the performance of lithium-ion batteries in extreme environments. It is hoped that these studies can guide the design of more durable and efficient lithium-ion batteries in the future，promoting the development of lithium-ion batteries in a wider range of fields.

Lithium-ion batteries quickly occupy the absolute leading position in the secondary battery market because of their high energy density and long cycling life. However，battery thermal runaway frequently causes fire accidents，so battery safety research is of great importance and urgency. Separator as one of the key components of the lithium-ion battery plays a crucial role in the safe operation of the battery. The development of high temperature resistant separators with excellent properties，such as high mechanical strength，low thermal shrinkage，and good self-extinguishing，can significantly enhance the safety of batteries at high temperatures. This paper systematically reviews the latest research progress in the development of high-temperature resistant separators for lithium-ion batteries，including the modification of commercial polyolefin separators and the structural and performance studies of three common high-temperature resistant separators （polyacrylonitrile，polyvinylidene fluoride，and aramid fiber）. The characteristics parameters of separators，such as thickness，porosity，ionic conductivity，and thermal shrinkage，are summarized. Finally，the future development direction and opportunities of high-temperature resistant separators are prospected.

Different crystal forms of manganese dioxide （MnO₂） are synthesized using KMnO₄， MnSO₄·H₂O， （NH4）₂S₂O₈， and hydrochloric acid as raw materials by precisely controlling the temperature and duration of a hydrothermal reaction. The structure and morphology of the materials are characterized using XRD， SEM， and TEM. The results show that the synthesized MnO₂ nanoparticles display different microscopic morphologies depending on their crystal forms. A comparison of their electrochemical performances indicates that δ-MnO₂， due to its unique flower-like structure， provides many reaction sites， leading to superior performance compared to other crystal forms of manganese dioxide. At a current density of 2 A/g， δ-MnO₂ achieves a capacity of 623.48 mAh/g after 1400 cycles. The kinetic properties of the MnO₂ electrode are investigated using cyclic voltammetry， electrochemical impedance spectroscopy， and constant current intermittent titration techniques. It reveals that δ-MnO₂ exhibits a higher Li⁺ diffusion rate.

In recent years，sodium-ion batteries have become a research hotspot in the world and are gradually moving toward industrialization. However，they still have shortcomings，including phase transition，structural degradation，and voltage plateau. Therefore，the development of positive electrode materials with better performance plays a crucial role in the capacity and energy density of sodium-ion batteries. This paper meticulously introduces three primary categories of positive electrode materials for sodium-ion batteries： transition metal oxides，polyanions，and Prussian blue. It elucidates the unique advantages of each material in diverse applications，acknowledges their inherent limitations，and presents a range of improvement strategies to address the challenges of low capacity and energy density. Additionally，by examining the investment trends and industrial layouts of sodium-ion battery positive electrode materials，this study analyzes the industrialization pathways and current development statuses of these three systems，summarizing the latest research advancements. Therefore，it is anticipated that with the ongoing maturation of theoretical foundations and industrial advancements，sodium-ion batteries will rapidly develop，and gradually integrate into daily life.

Prussian blue analogous compounds （PBAs） have emerged as promising candidates for cathode materials in next-generation sodium-ion batteries （SIBs）， attributed to their inherent thermodynamic stability， expansive ion intercalation/deintercalation pathways， abundant electrochemically active sites， as well as their adjustable chemical compositions and elemental ratios. However， the electrochemical performance of these materials is frequently compromised by crystal defects and high levels of crystalline and interstitial water content. This review delves into the structure of PBAs， categorizing them from both single-electron and two-electron perspectives. It examines the prevalent challenges faced by PBAs， systematically reviewing existing typical modification strategies across six dimensions： crystallinity control， defect mitigation， morphology modulation， ion doping/substitution， component optimization， and carbon coating/compositing. Furthermore， it offers insights into the current status of PBAs in transitioning from laboratory research to industrial applications. Looking ahead， this paper anticipates the development of PBAs in the realm of SIBs， expecting them to advance from the laboratory stage to industrialized applications through advancements in materials engineering and surface science.

The excellent comprehensive high-temperature performance of Ti₂AlNb alloy makes it a potential substitute for some nickel-based alloys， serving as a key structural material for weight reduction in aviation engines. In response to the lightweight design requirements of future high-performance aviation engines， a combination of statistical comparison， control experiments， finite element simulation analysis， and other methods are used to analyse the material properties， alloy cold/hot processing performance， weight reduction benefits， etc. The advantages， potential， and remaining issues of the alloy’s application in aviation engines are discussed. The analysis results indicate the feasibility of using Ti₂AlNb alloy in aviation engines， with significant advantages in weight reduction： the alloy achieves a good balance of strength， toughness， and plasticity without obvious shortcomings； it has acceptable cold and hot processing performance， and can obtain engineering-sized parts through deformation， casting， and other methods； its combustion resistance is superior to traditional titanium alloys； when applied to static components such as casings， it can achieve a weight reduction of 35.3% compared to high-temperature alloys， and when applied to integral blade/disks and rotor components， it can achieve a weight reduction of 37.3% compared to nickel-based high-temperature alloys.

Polytetrafluoroethylene （PTFE）， as a special engineering plastic， has many advantages such as excellent self-lubricating properties， good chemical stability， and a wide range of operating temperatures. However， its core disadvantages are poor wear resistance and easy wear， which seriously shorten its service life. Starting from the structural characteristics of PTFE molecules， this article takes the transfer film theory as the main thread to deeply analyze the friction and wear mechanism of PTFE and the research and development process. It summarizes the tribological modification methods of PTFE， analyzes the common methods of surface modification， filling modification， and blending modification， compares the internal mechanisms of these three types of modification methods， and summarizes the development trend of composite modification. Finally， based on recent research achievements and existing problems in the research process， the research direction of PTFE tribological modification is discussed， some suggestions on the quantitative study of transfer film， the industrial feasibility of multimode type collaborative composite modification， the selection and application of modification system under actual working conditions are given.

Zirconia toughened alumina （ZTA） ceramics exhibit excellent mechanical properties compared to single-phase Al₂O₃ and ZrO₂ ceramics， demonstrating broader application prospects in high-end industrial fields such as electronics， biomedicine， and semiconductors. This paper reviews the toughening mechanism of ZTA ceramics and summarizes recent research progress， both domestic and international， on three aspects： powder preparation， sintering methods， and the introduction of the third phase. It focuses on analyzing the role of third-phase incorporation in ZTA ceramics through the use of various sintering techniques and processing methods. Finally， it points out that the nano-structuring of powders， fine control of advanced sintering techniques， and exploration of the microstructure through third-phase modulation are key directions for future research.

With the increasing demand for energy storage， higher requirements have been put forward for the cycle life， capacity， working stability， and rate performances in batteries. Lithium-ion batteries （LIBs） are favoured for their excellent electrochemical performance and broad development prospects and have been widely applied in mobile devices， electric vehicles， and other fields. However， the bottleneck factors such as life decay and high cost have hindered the further promotion and application of LIBs. This article reviews the main factors affecting the cycle life decay of LIBs， including damage and gas production of positive electrode materials， as well as the consumption of active lithium caused by the repair of negative electrode solid electrolyte interface （SEI） membrane and the formation of lithium dendrites. Effective ways for scientific researchers to improve the life properties of LIBs in recent years， including the structural design of negative electrode materials and the control of SEI film stability， as well as ion doping and surface coating of positive electrode materials， are also summarized. Finally， the future development trends in this field from three aspects， such as multi-element doping， uniform coating new technology， and stable SEI film control are proposed based on the bottleneck issues in the development of lithium-ion batteries.

Sodium-ion batteries have garnered significant attention owing to their abundant sodium reserves， cost-effectiveness， and operational principles akin to lithium-ion batteries， exhibiting immense potential for large-scale energy storage applications. The advancement of sodium-ion batteries with rapid charge-discharge capabilities can effectively cater to frequency modulation needs in large-scale energy storage systems. As a pivotal component， the electrolyte in sodium-ion batteries plays a crucial role in electrode/electrolyte interface reactions and significantly influences the fast-charging characteristics of these batteries. This paper delve into the opportunities and challenges associated with fast-charging electrolytes in sodium-ion batteries. Furthermore， we discuss the intimate relationship between the fast-charging performance of sodium-ion batteries and the properties of the electrolyte， focusing on the electrolyte’s transmission characteristics and electrochemical stability. Lastly， we summarize the current development status of fast-charging electrolytes based on various solvent systems and propose a general design strategy. The comprehensive analysis presented in this paper offers valuable insights and guidance for the research and development of sodium-ion batteries with rapid charge-discharge capabilities.

Fluorinated and cyanosubstituted lithium sulfonimide （LiFBTFSI and LiCBTFSI） are synthesized from 4-fluorobenzene sulfonyl chloride and 4-cyanobenzene sulfonyl chloride by sulfonylation and ion exchange， respectively. Two PEO based polymer electrolytes （PEO₂₀-LiFBTFSI and PEO₂₀-LiCBTFSI） are prepared by solution casting， and their micromorphology， thermal stability and electrochemical properties are characterized. The results show that at 60 ℃ and EO/Li⁺=20， the ionic conductivity of the two solid electrolyte reaches 10^-4 S/cm， the electrochemical stability window is greater than 5 V， and the battery assembled with lithium iron phosphate has a high initial discharge capacity （0.1 C， ≈150 mAh·g^-1）. Compared with the fluorine PEO₂₀-LiFBTFSI solid electrolyte， the cyan-containing PEO₂₀-LiCBTFSI solid electrolyte has better electrochemical stability and interface compatibility. After 50 cycles， the specific discharge capacity of the battery is 137.4 mAh·g^-1， and the capacity retention rate is 93.0%. In addition， the cyano-containing PEO₂₀-LiCBTFSI solid electrolyte has good electrochemical stability with lithium metal， and the assembled lithium symmetric battery operates stably at a current density of 0.1 mA/cm² for 500 h without short circuit.

Sodium iron phosphate （NaFePO₄， NFP）， a cathode material renowned for its stable three-dimensional structure and high theoretical specific capacity of 154 mAh·g^-1， stands out as a pivotal component in sodium ion batteries. NFP exists in two distinct crystal structures： triphylite and maricite. The triphylite variety boasts a long lifespan and high reversible capacity， yet its structural thermodynamic instability poses challenges for conventional synthesis methods. Conversely， the maricite structure is stable but exhibits electrochemically inert characteristics due to the absence of cationic transport channels. Both structures suffer from low conductivity and sluggish reaction kinetics， hindering their industrial applications. This paper delves into the characteristics of these two crystal structures and summarizes various synthesis methods， including solid-state， hydrothermal， displacement， and electrospinning， as well as modification techniques such as crystal structure regulation and material surface modification. Additionally， it identifies the key challenges faced by NFP cathodes and presents potential solutions， while also outlining future research directions.

Separator modification represents a prevalent approach to inhibiting lithium dendrite growth and enhancing battery safety. In this study， lithium metal serves as the negative electrode， LiFePO₄ as the cathode， and a graphene coating modified polypropylene separator is employed. Lithium batteries are assembled and undergo rigorous testing， including cycling tests， rate capability tests， electrochemical impedance spectroscopy （EIS） measurements， and morphological analysis of the lithium negative electrode before and after cycling. The primary focus is to investigate the influence of positioning the graphene coating towards either the cathode or the negative electrode on battery performance. Cycle performance results indicate that when the graphene coating faces the negative electrode， the battery exhibits an initial discharge-specific capacity of 168 mAh/g at 0.2 C. After enduring 500 cycles， the discharge-specific capacity remains stable at 154 mAh/g， yielding a capacity retention rate of 91.67%. EIS analysis further reveals that the battery with the graphene coating oriented towards the negative electrode exhibits decreased interfacial resistance and improved reaction kinetics. Moreover， the surface of the cycled lithium negative electrode remains smooth and uniform， devoid of significant lithium dendrite formation. Consequently， lithium batteries configured with the graphene coating facing the negative electrode demonstrate superior cycle performance and heightened safety.

As new energy vehicles proliferate and energy storage systems scale up， lithium-ion batteries confront market risks stemming from resource scarcity and price volatility. In this context， sodium-ion batteries have emerged as a promising alternative， leveraging their abundant resources to potentially complement lithium-ion batteries in large-scale electrochemical energy storage and low-speed electric vehicles. Despite the rapid surge in sodium-ion battery research and the onset of commercialization initiatives globally， several market and technological prerequisites persist， posing challenges compared to the well-established lithium-ion battery system. This article provides a concise overview of sodium-ion batteries from a commercialization perspective， tracing their development history and current industry standing. It delves into the core positive and negative electrode materials， costs， and application prospects within the existing sodium storage electrode material systems. Additionally， the article presents a forward-looking analysis of future opportunities and challenges， aiming to guide further advancements in the sodium-ion battery industry.

In recent years， with the proposed goals of “carbon peaking” and “carbon neutrality”， the rapid development of new energy electric vehicles has led to a soaring demand for lithium ion batteries （LIBs）. However， the widespread use of LIBs inevitably results in a sharp increase in the number of retired batteries， making the efficient recycling and reuse of these waste batteries an urgent issue. LIBs are categorized into four main types： ternary lithium ion batteries， lithium iron phosphate lithium ion batteries， lithium cobalt oxide lithium ion batteries， and lithium manganese oxide lithium ion batteries. Among them， lithium iron phosphate lithium ion batteries stand out for their extensive applications and high recycling potential. Currently， the recycling of waste lithium iron phosphate lithium ion batteries primarily focuses on the recovery of valuable elements from cathode materials， high-value reuse of materials， and the recycling and functional development of anode materials. This paper provides a comprehensive review of recent advances in the recycling and reuse of lithium iron phosphate lithium ion battery materials， highlighting processes such as pyrometallurgical and hydrometallurgical recovery， the regeneration of cathode materials and their innovative applications in catalysts， as well as the reprocessing of waste anode graphite and the preparation of graphite-based functional materials. Finally， combined with the current technical level， the recycling and utilization of lithium iron phosphate lithium ion battery materials are summarized， and it is pointed out that the future direction of lithium iron phosphate lithium ion battery materials recycling should highlight the trend of optimization classification and recycling strategy， innovative recycling technology， comprehensive recycling， in-depth research on recycling mechanism， and optimization of electrode material design. At the same time， the challenges of future recycling technology are complex battery composition， irregular battery shape， electrolyte processing problems， and low recovery rate.

Lithium-based batteries （LBBs） are widely used in portable electronic devices and electric vehicles， serving as a pivotal component in both current and emerging energy storage technologies. Lithium-sulfur batteries are considered as the ideal choice for the next generation of high-energy density batteries due to their high energy density （2600 Wh·kg^-1）. Due to the unique long chain structure and high adhesion force of polymer materials， it shows excellent performance advantages in the application of lithium-sulfur battery binder. This paper reviews the latest research progress and application prospect of polymer materials in improving the safety and stability of lithium batteries. The application of polymer materials in modified separators， solid state electrolytes， binders and flame retardants for LBBs is mainly discussed. In addition， the inhibition ability and mechanism of polymer artificial solid state electrolyte interface film and solid state electrolyte on dendrite growth are introduced， and the flame retardant property of polymer and its mechanism as solid state electrolyte are pointed out. Finally， based on the excellent plasticity and chemical controllability of polymers， the potential of high ionic conductivity and interface stability achieved by molecular design in LBBs energy storage is prospected.

To clarify the evolution of the interfacial microstructure of GH4065A superalloy during plastic deformation bonding， the GH4065A superalloy is bonded under temperatures of 1050-1110 ℃ with the pressure of 20-40 MPa and a time range of 20-35 min. OM，SEM， and EBSD were employed to characterize the special positions between bonding regions and unbinding regions to investigate further the influence of plastic deformation bonding parameters（bonding temperature，holding time，and bonding pressure） on the microstructural evolution of the interface.This study focuses on the nucleation of new recrystallization grains in the bonding area and the healing of the original interface. The results show that increasing the bonding temperature， pressure and the holding time will facilitate the healing of the interface. but at the same time， it will also prompte the coarsening of the grains simultaneously. The joint obtained under 1080 ℃，30 MPa，30 min has uniform microstructure and no obvious defects， exhibiting an excellent metallurgical bonding effect.The results of EBSD show that the discontinuous dynamic recrystallization characterized by strain-induced grain boundary bulging is the dominant mechanism， and continuous dynamic recrystallization characterized by subgrain progressive rotation occurs in the bonding process. Moreover， the dynamic recrystallization（DRX）nuclei will grow toward the interface with ongoing deformation， contributing to the healing of the original interface.The metallurgical bonding caused by plastic deformation bonding mainly experiences three stages： initial contact， nucleation and grain growth， and joint formation.

The SiC-BN/SiOC ceramic matrix composites are prepared through the precursor infiltration pyrolysis（PIP） process， using wave-absorbing SiC fibers with in-situ BN coatings as reinforcements and SiOC ceramic as the matrix. After 7 PIP preparation cycles， the composite achieves densification with density of 2.05 g/cm³ and porosity of 4.28%. The dielectric constants are tested with vector network analyzer. Using transmission line theory， the microwave-absorbing properties of the composites from room temperature to 800 ℃ at 8.2-18 GHz are optimized. The results show that the dielectric constants of the SiC-BN/SiOC composites exhibits significant frequency dispersion effects， leading to broadband microwave-absorbing properties. When the thickness of the composites is 2.1 mm， the maximum bandwidth of the reflection loss better than -10 dB in the X band and the Ku band is 5.7 GHz. As the ambient temperature increases， the real and imaginary parts of the complex permittivity of the composites both increase. For reflection loss better than -5 dB in a wide bandwidth， the optimum thicknesses decrease from 2.3 mm （200 ℃） to 1.1 mm （800 ℃）.

GH4065A is a newly developed high-performance cast-wrought Ni-base superalloy with ultra-low C and N content used for advanced turbine engine disc. In this study， the alloy’s inclusions of the alloy are characterized and statistically analyzed. To investigate the fatigue fracture mechanism， strain-controlled fatigue tests are conducted at 400 ℃ and 650 ℃ on the fine-grained and coarse-grained samples respectively. The results show that the alloy’s inclusions of the alloy are mainly nitrides. For the fine-grained samples， discrete nitride particles and clustered nitrides both with a critical size larger than the average grain size are responsible for the fatigue crack initiation. When subjected to high-level strains （≥0.9%）， fatigue failure primarily originates from surface nitrides， with rare occurrences of boride and oxide initiation. Surface crack induced by Al₂O₃， rather than boride or MgSiO₃， is found to significantly reduce the fatigue life. Higher fatigue temperature results in reduced life cycles. When under lower levels of strain， however， subsurface/internal nitride-facet initiations dominate and fatigue life is prolonged by the elevated temperature. In the coarse-grained samples， fatigue failures at 400 ℃ are found to be initiated by quasi-cleavage cracking mechanism. Due to the increased grain size， the inclusion-induced crack initiation is suppressed while slip-induced cleavage cracking mechanism becomes predominant.

Infrared radiation at the hot-section of the aero engine is easily detected by infrared detectors， which is not conducive to aircraft service in a complex monitoring environment. How to reduce the infrared radiation characteristics of high-temperature parts of aero engine and improve the high-temperature infrared stealth performance of the aero engine is a difficult problem that needs to be solved. This paper discusses the infrared stealth mechanisms and research status of metal-based， inorganic non-metallic， and structural infrared stealth materials with potential applications in high-temperature environments. It also highlights the future development trends for high-temperature infrared stealth materials， including the need for further investigation into the failure mechanisms of these materials， the integration of temperature control methods to meet higher-temperature stealth requirements， and the necessity to develop comprehensive stealth performance to ensure the capability of aircraft to remain stealthy in complex environments.

A large number of droplets and their products produced by titanium fire combustion in aeroengine compressor will cause burn through and non-inclusiveness failure of titanium alloy casing. This has shown great harm. In this study， a quantitative evaluation method for titanium fire inclusiveness of compressor was explored based on the mechanism of titanium alloy melt drop ablation and laser ignition technology. A test and evaluation method was established with the characteristic parameters of the melt drop penetration resistance of two configurations of TC4 titanium alloy casing， namely horizontal expansion and vertical drip. Meanwhile， the diffusion behavior of titanium fire and the critical failure conditions under simulated airflow environment were varified by experiments as well. Those results show that the mechanism of titanium alloy droplet burning through the casing lies in the local high heat concentration formed at the droplet contact interface. Under the action of heat transfer， the kinetic energy of the atoms in the base of the titanium alloy cartridge increases rapidly， forming a penetrating liquid phase， and finally causing burn-through， that is， titanium non-inclusiveness failure. When the droplet moves horizontally in the process of extended combustion， it will be affected by some mechanism such as reverse airflow， which will weaken the expansion effect. When the droplet is adhered to the surface of the casing simulation for a long time under the action of gravity or centrifugal force， the heat released is enough to burn through the titanium alloy casing. Its critical thickness is between 1.5-2 mm.

Lithium fluorocarbon batteries have gained widespread application in areas such as implantable medical devices， military application， sensors， wireless devices， and aerospace due to their high energy density， excellent safety performance， and low self-discharge rates. The performance of lithium fluorocarbon batteries is particularly critical in extending the service life of leadless pacemakers. This article reviews the strategies for enhancing the capacity and voltage of lithium fluorocarbon batteries. The following three aspects are mainly discussed：firstly， the advancement of high specific capacity and high voltage fluorocarbon， involving the optimization of carbon source structure， pre- and post-fluorination treatment， and control of fluorination methods； secondly， the development of high-performance electrolytes， including the use of low concentration lithium salts with solvents processing high donor number， as well as reactive lithium salts and solvents； lastly， the optimization of battery manufacturing processes， particularly focusing on thick electrode and electrolyte injection processes. A comprehensive analysis indicates that by meticulously modulating the structure of carbon sources， optimizing the proportion of fluorocarbon bonds， improving electrolyte formulations， and innovating process technologies， it is possible to develop lithium fluorocarbon batteries with higher capacity and voltage， thereby effectively enhancing the service life of leadless pacemakers.

In light of the “rich coal，poor oil，and scarce gas” resource status in China，developing carbon electrode materials from coal can accelerate the transformation of clean and efficient utilization of coal and the realization of “dual carbon” goals. Herein，the porous carbon is synthesized from Shenmu bituminous coal via a one-step KOH activation strategy. The results indicate that the resultant carbon possesses a hierarchical porous structure with a surface area of 2094.5 m²·g^-1 and pore volume of 0.96 cm³·g^-1，abundant graphitized microcrystals，N/O co-doping，and excellent hydrophilicity. By employing as-fabricated carbon as cathode，2 mol·L^-1 ZnSO₄ aqueous solution as electrolyte，and Zn foil as anode，the assembled coin-type Zn-ion hybrid supercapacitors （ZIHSCs） exhibit a high capacity of 178.7 mAh·g^-1 at 0.1 A·g^-1 and retain 89.2 mAh·g^-1 by enlarging the current density 200 times to 20 A·g^-1，manifesting an eminent rate performance. Importantly，the maximum energy density and power density of ZIHSCs can reach 142 Wh·kg^-1 and 16854.9 W·kg^-1，respectively. Furthermore，the quasi-solid ZIHSCs based on the gel electrolyte of gelatin@ZnSO₄ also deliver outstanding electrochemical capability and excellent flexibility.

To solve the problems in Fenton-like reactions， such as slow Fe³⁺/Fe²⁺ redox cycle， low electron transfer rate at the material interface， and high electron density of Fe³⁺ in Fe-MOFs， Fe-Cu bimetallic nitro-functionalized MOFs material （NMIL-88B-Cu-1） is synthesized by a one-step solvothermal method based on the principle of redox coupling reaction. The material is characterized and applied to effectively degrade Congo red （CR） in a Fenton-like process. The effects of different materials， H₂O₂ dosage， pH， CR concentration， and coexisting ions on the degradation of CR are investigated. The stability of materials is verified， and the catalytic degradation mechanism is proposed. The results show that when the molar percentage of Fe³⁺ and Cu²⁺ are both 50%， NMIL-88B-Cu-1 with hexagonal rod structure and mesoporous can be assembled on α-Fe₂O₃. When CR is 10 mg/L， pH value is 3-7， NMIL-88B-Cu-1 catalyst is 0.1 g/L， and H₂O₂ is 0.5 mol/L， CR can be rapidly and efficiently degraded in 15 min. The degradation efficiency of CR is 98%， which is 1.95 times that of NO₂-MIL-88B and 2.24 times that of MIL-88B， respectively. The CR degradation efficiency could still reach 92% after 4 cycles， the content ratio of Fe³⁺/Fe²⁺ is only reduced by 5%， and its crystal structure remains the same， exhibiting the high cycle stability of NMIL-88B-Cu-1. In the system SO {}_{\mathrm{4}}^{\mathrm{2}-} and NO {}_{\mathrm{3}}^{-} do not affect the degradation of CR， while Cl^- and H₂PO {}_{\mathrm{4}}^{-} with a concentration of 0.09 mo/L show an inhibitory effect on the degradation of CR. The analysis of the mechanism shows that the electron density of Fe³⁺ in the center of the nitro-functionalized material is low， and the introduction of Cu²⁺ constructs Fe-Cu bimetallic MOFs materials. The redox coupling reaction between Fe and Cu and the synergistic effect of Fe-Cu promote the formation of Fe²⁺ effectively， and accelerate the e^- transfer at the interface of NMIL-88B. The generated ·OH can oxidize and degrade CR into inorganic small molecules such as CO₂ and H₂O.

The enrichment of nitrate pollutants in water will bring great harm to ecology and seriously threaten human life and health. It is significant to study the electrocatalytic materials of high efficiency electrocatalytic nitrate reduction to ammonia for ecological protection and formation of the nitrogen cycle. In this study， a self-supporting dendritic Cu/CF （D-Cu/CF） electrode is deposited on the copper foam （CF） skeleton by the hydrogen bubble dynamic template （DHBT）. The orientation tip of the three-dimensional dendrite structure greatly increases the number of active sites and intrinsic activity when it is used in synthesizing ammonia by nitrate electroreduction. The effects of deposition time and different potentials on electrochemical performance are investigated. Under the optimum conditions， D-Cu/CF electrode shows an ammonia production rate of 0.379 mmol·h^-1·cm^-2 and a Faraday efficiency of 92.8%. The ammonia production rate is stable and the Faraday efficiency is above 90% after 6 cycles of nitrate electroreduction. Furthermore， the D-Cu/CF electrocatalyst exhibits good electroreduction performance in the actual water sample test， showing great potential practical application value.

A photocatalyst g-C₃N _x @CN with defective carbon nitride （g-C₃N _x ） encapsulated by CN shells is prepared by in-situ growth and high-temperature dezincification. The structural， morphological， and compositional characterization of g-C₃N _x @CN has been analyzed and characterized by various analytical means. First， g-C₃N _x with nitrogen defects is prepared by high-temperature polycondensation of melamine and high-temperature denitration of Mg powder， followed by in-situ growth of ZIF-8 by loading ZnO nanoparticles. Finally， g-C₃N _x @ZIF-8 is dezincified at high temperature， and the CN shell-encapsulated visible light catalyst material g-C₃N _x @CN with double defects （N， Zn） with ZIF-8 is prepared. The study demonstrates that the g-C₃N _x @CN catalyst exhibits strong visible photocatalytic activity and effectively degrades methylene blue and 2，4-dichlorophenol within 240 min， with the best performance of the g-C₃N _x @CN-5∶4 composite. The single linear oxygen （1O₂） plays a dominant role in the reaction system. In the cycle test， the g-C₃N _x @CN shows excellent recycling and light stability. This study extends the study of defective carbon nitride materials in visible light absorption and provides a viable method for the derivation of metal catalysts to inorganic non-metal catalysts.

The joining of aluminum/copper dissimilar metals is successfully achieved by ultrasonic-assisted nano-enhanced plasma arc fusion brazing， and a well-formed aluminum/copper lap joint is obtained. The effects of ultrasonic waves and SiO₂ nanoparticles on the macroscopic and microscopic morphology， organizational structure， mechanical properties and conductive properties of lap joints are analyzed and studied by SEM， EDS， XRD， tensile test and conductivity test. The results show that the lap joint is obtained under the coupling action of ultrasonic waves and SiO₂ nanoparticles， and the spreading and wetting effect of liquid aluminum on the copper surface is better， the front side of the weld is well formed， and the joint is mainly composed of intermetallic compound layer region and Al-Cu eutectic region. The thickness of the intermetallic compound layer is reduced obviously，and the mechanical properties of the joint is significantly improved. The relative conductivity of the aluminum/copper joint using SiO₂ nanoparticles and ultrasonic waves is 153.527%IACS， exhibiting improved mechanical properties and electrical conductivity.

为制备高性能、低成本的稀贵金属电催化析氢材料,采用化学沉淀法结合热分解法制备RuO₂-NiO/NF异质结构析氢电催化剂,该电极在碱性析氢反应（HER）中表现出优异的催化活性和稳定性。通过表征、测试以及理论（DFT）计算分析,证明RuO₂和NiO结合产生的异质结构界面是该催化剂性能提升的核心,该界面上发生电荷转移导致双活性位点的产生,使不同种类的吸附质在不同活性位点选择性吸附,协同促进了析氢反应的各基元反应步骤,使得该催化剂在碱性析氢反应中表现优异:10 mA·cm^-2电流密度下的析氢过电位仅为52 mV,Tafel斜率为47.5 mV·dec^-1,100 mV下的TOF达到0.342 s^-1,且在200 mA·cm^-2的电流密度下、经100 h稳定性测试后仍维持稳定电势。综上所述,本工作从界面工程角度成功构筑RuO₂-NiO/NF异质结构催化剂,并对其HER机理进行了探讨,为Ni基化合物异质结构催化剂的构建及在电催化领域的应用提供了新思路。

AlCoCrFeNi_2.1 eutectic high entropy alloy has excellent mechanical properties and promising applications in fields such as hydrogen storage and transportation. The surface of the alloy is hydrogenated by electrochemical hydrogenation， and tensile tests are carried out on H-charged and H-free specimens to compare and analyze the fracture morphology characteristics， and the effect of hydrogen-induced precipitated phase evolution on the mechanical properties of the alloy is studied. The results show that compared with the samples without hydrogen charging， the yield strength of the hydrogen charging solution samples with sulfuric acid concentrations of 0.5 mol/L and 1.0 mol/L decreases by 14.60% and 20.22%， respectively， and the tensile strength decreases by 15.50% and 25.15%， respectively. Additionally， the mechanical properties of the alloy further decrease with the increase of the hydrogen ion concentration in the hydrogen-charged solution， and the fracture region near the surface shows more obvious brittle fracture characteristics. The precipitated phase， which undergoes a phase transition after hydrogen charging， remains on the surface of the BCC phase during fracture to form a higher and denser raised structure， and a structure distinct from the two phases is also found at the phase boundary. The evolution of hydrogen-induced nanoprecipitated phases leads to a decrease in the overall mechanical properties of the alloy.

In this study， 0.95MgTiO₃-0.05CaTiO₃ powders are synthesized via a high-temperature solid-phase reaction， utilizing TiO₂，CaCO₃，and Mg（OH）₂ as the primary reactants. Guided by the phase diagram， sintering aids comprising Li₂B₄O₇-Al₂O₃， which possess a low melting point， are formulated to facilitate the low-temperature sintering process of 0.95MgTiO₃-0.05CaTiO₃ microwave dielectric ceramics. The study comprehensively investigates the influence of the synthesis temperature （900-1100 ℃） on the phase composition of calcium magnesium titanate powder， as well as the effects of sintering temperature （1175-1250 ℃） and aid content （1%-5%， mass fraction， the same below） on the density， microstructure， dielectric constant， quality factor， and frequency-temperature coefficient of calcium magnesium titanate ceramics. The results indicates that 0.95MgTiO₃-0.05CaTiO₃ powders could be successfully synthesized at a reaction temperature of 1100 ℃. The incorporation of sintering aids effectively reduced the sintering temperature of the ceramics. However， excessive addition （5%） resulted in decreased density and dielectric properties. Optimal performance is achieved with an aid content of 3% and a sintering temperature of 1225 ℃， producing 0.95MgTiO₃-0.05CaTiO₃ ceramic with a relative density of 98.70%， a dielectric constant of 20.38， a quality factor of 37240 GHz， and a frequency-temperature coefficient of -9.6×10^-6 ℃^-1.

Graphite composite bipolar plates have received widespread attention in the field of fuel cells due to their excellent conductivity and corrosion resistance. The traditional method of molding graphite composite bipolar plates has problems such as low efficiency and complex operation. Therefore， this study proposes a preform process scheme that simplifies the process operation and improves efficiency by rolling graphite/resin mixed powder into a pre-compress plate through a rolling machine and then rapidly molding it. By optimizing the rolling parameters and adding auxiliary binders， the problems of insufficient compaction and structural defects in the pre-compress plate are solved， improving the reliability of the process and material utilization rate. The results show that increasing the temperature and reducing the roll distance can both improve the compaction density of the pre-compress plate. Adding PTFE as an auxiliary binder can effectively improve the defects during the rolling process， but excessive addition can have a negative impact on conductivity and airtightness. The optimal addition ratio is 5% （mass fraction）. Compared with traditional direct compression molding， the bipolar plate prepared by this scheme has a slight decrease in in-plane conductivity， but its bending strength is increased by 14.2% and the preparation cycle is shortened to 42.9%， significantly improving production efficiency.

The elastic limit is a critical parameter in spring design， which has a significant impact on the spring characteristic. The influence of cold drawing on the strength， elastic limit， elastic after-effect， and microstructure of 07Cr17Ni7Al ultrafine wire with a diameter of 0.3 mm for valve springs is investigated using room temperature tensile tests， single arm bending method， optical microscope（OM）， X-ray diffraction（XRD） and scanning electron microscope（SEM）. Different mathematical models are used to fit and analyze the deformation and martensite content， deformation-elastic limit， and stress-elastic after-effect. The results show that the solid solution 07Cr17Ni7Al wire is composed of austenite and a small amount of ferrite. Cold drawing transforms austenite into martensite， the content of deformation-induced martensite （DIM） increases with increasing deformation. The relationship between DIM content and cold-drawn equivalent strain （η） conforms to the Olson-Cohen model. When η reaches 1.64， the DIM content is about 92%， and the DIM reaches saturation. The tensile strength of wire exhibits a linear relationship with η， and the larger the deformation， the higher the tensile strength. The relationship between the elastic limit and the η follows an “S” shaped curve and conforms to the DoseResp model. The elastic limit increases with increasing deformation. When the η reaches 1.64 or more， the elastic limit tends to be gentle. The elastic after-effect increases with increasing stress， which conforms to the PWL2 model. There exists a “critical stress for elastic after-effect”. When the stress exceeds this critical value， the rate of elastic after-effect increases by 2-11 times with increasing stress. When the η is 1.64-2.41， the 07Cr17Ni7Al wire has good mechanical and elastic properties.

Fe-based amorphous alloy coatings have emerged as a key area of research in the field of surface engineering due to its high strength， hardness， and exceptional wear and corrosion resistance. This paper provides a comprehensive review of the preparation， performance， and application status of Fe-based amorphous alloy coatings. It also summarizes the fundamental principles of amorphous alloy material design and typical Fe-based amorphous alloy coatings material systems. The focus is on three coating preparation technologies： thermal spraying， cold spraying， and laser cladding. Additionally， it compiles the research progress made in understanding the tribological properties and corrosion resistance of Fe-based amorphous alloy coatings. Furthermore， it briefly outlines the applications of these coatings in military， medical， industrial fields etc. Finally， it is pointed out that in-depth study of amorphous formation， the establishment of specialized material systems while matching the working environment， and the adoption of post-processing or more efficient preparation methods are the development trends for future research work in this field.

Ultrathin-gauge non-oriented silicon steel sheets are produced by both one-stage and two-stage cold-rolling processes.The effects of rolling and annealing on the evolution of microstructure， texture， mechanical， and magnetic properties are investigated. It is found that the microstructure resulting from one-stage cold-rolling primarily comprised fibrous deformation structures， resulting in refined grain size after final recrystallization. Notably， the ｛001｝〈110〉 and ｛223｝〈110〉 textures persisted in the low-temperature recrystallized state，which is inherited from cold-rolled sheets. Conversely， during high-temperature annealing， a notable texture transformation occurs， with the α* and γ textures emerging as the dominant features. The two-stage cold-rolling method promotes the formation of shear bands， leading to a larger grain size in the final annealed structure. These shear bands served as crucial nucleation sites for Goss grains， thereby facilitating the development of Goss texture during the annealing process. Furthermore， the ｛001｝〈110〉 texture aligned along the λ orientation line towards the ｛001｝〈010〉 texture， accompanied by a gradual decrease in the intensity of the γ texture. As the annealing temperature increases， the iron loss initially decreases rapidly and slowly， whereas the magnetic induction intensity initially rises before stabilizing. Compared with the one-stage cold-rolling method， the ultrathin-gauge non-oriented silicon steel prepared by the two-stage cold-rolling method has lower iron loss and higher magnetic induction intensity. This superior performance can be attributed to the formation of shear bands， which enhance the formation of favorable Goss and Cube textures， the suppression of detrimental γ texture， and the attainment of a larger recrystallized grain size.With increasing the annealing temperature， the yield strength of both the one-stage and two-stage cold-rolling annealed sheets initially decreases dramatically before trending to be stabilized. The yield strength of ultra-thin non-oriented silicon steel produced by the one-stage cold-rolling method is higher than that produced by two-stage cold-rolling. The optimal comprehensive properties （both mechanical and magnetic properties） are achieved through a two-stage cold-rolling process followed by annealing at 800 ℃， which yields a mid/high frequency-iron loss P _10/400 of 12.34 W/kg， P of 36.12 W/kg， a magnetic induction intensity B ₅₀ of 1.71 T and a yield strength of 389 MPa.

This paper proposes a non-isothermal solid solution-forging integrated hot forming process for 7075 aluminum alloy. After solid solution treatment， the aluminum alloy is directly placed into the mold for forging， then quenched and subjected to artificial aging treatment. The influence of water entry temperature and aging parameters on the microstructure and properties of 7075 aluminum alloy is studied under this process， through the construction of a temperature-time-property（TTP） curve. Additionally， machine learning techniques are integrated to optimize and match the key process parameters. The results reveal that the nose temperature of the TTP curve is 315 ℃， and the mechanical properties of the alloy increase with the increase of water temperature after aging， a double-peak phenomenon after non-isothermal forging and aging is observed. When the inlet temperature is 380 ℃， the optimal aging parameters are 115 ℃-26 h and the peak hardness is 182HV. After training， the prediction accuracy of the BP neural network model is 94.9977%. Experimental verification of the optimal process parameters predicted by the model shows that its prediction similarity is 96.9%. Compared with traditional forging processes， this process can achieve high mechanical properties than traditional forged T6-state 7075 aluminum alloy while reducing procedural steps and energy consumption.

IC21 alloy， as a new Ni₃Al-based single crystal superalloy， has become an ideal material for manufacturing a new generation of aero-engine turbine guide vanes due to its high melting point， excellent high-temperature performance， and creep resistance performance. However， turbine guide vanes have complex structures， such as deep holes and deep and narrow slots， which are difficult to be processed efficiently by traditional machining techniques. Electrochemical machining has become the main method for processing such complex structures due to its advantages， such as no tool loss， high material removal rate， and no cutting stress and thermal effect. This paper focuses on the electrochemical dissolution behavior of IC21 nickel-based single crystal alloy in NaCl and NaNO₃ electrolytes. The electrochemical reaction characteristics of IC21 alloy in different electrolytes are analysed by linear scanning voltammetric polarisation curve measurements. In addition， the dissolution characteristics and selective dissolution phenomena of the alloy under different electrolytes and current densities are investigated by current efficiency measurements and surface micro-morphology analysis. It is shown that IC21 alloy exhibits typical passivation-super-passivation transition phenomena in both NaCl and NaNO₃ electrolytes， in which the oxide layer formed in NaNO₃ electrolyte exhibits higher stability. Current efficiency measurements show that the dissolution efficiency of IC21 alloy is more stable in NaCl electrolyte， and the dissolution efficiency in NaNO₃ electrolyte gradually decreases with the increase of the current density， which exhibits different characteristics from the traditional theory. The dissolution surface morphology analysis further reveals the existence of the selective dissolution phenomenon of IC21 alloy under ECM conditions， and its microscopic mechanism is discussed. Based on the above experimental results， a theoretical model of electrochemical dissolution of IC21 alloy under different electrolyte and current density conditions is established， which provides a theoretical basis for the development and application of ECM processes for IC21 alloy.

A comprehensive long-term aging study has been conducted on the third-generation nickel-based single-crystal superalloy DD10 at temperatures of 900 ℃ and 1050 ℃. This investigation systematically analyzes the microstructural evolution disparities between dendrite regions， as well as the evolution of the distribution characteristics of the γ' phase and TCP phase under various aging conditions. The results indicate that during aging at 900 ℃， the γ' phase undergoes gradual coarsening and growth with increasing aging time. Conversely， at 1050 ℃， the γ' phase coarsens rapidly and retains a cubic shape after 100 h of aging. The trend of γ' phase coarsening and growth is consistent between dendrite regions， with minimal difference in the average size of the γ' phase within these regions under the same aging duration. Quantitative statistical analysis reveals that the coarsening of the γ' phase aligns with the Lifshitz-Slyozov-Wagner （LSW） model. Following aging at 1050 ℃ for 500 h or more， the γ' phase within the dendritic core adopts an irregular shape， and stress within the dendrites leads to the formation of a valuated structure in the γ' phase between dendrites， with the valuation direction coinciding with the primary dendrite growth direction ［001］. During aging at both 900 ℃ and 1050 ℃， TCP phase precipitation between dendrites is minimal， whereas the TCP phase volume fraction within dendrite stems increases significantly with increasing temperature and time. After aging at 1050 ℃ for 2000 h， the TCP phase volume fraction reaches 8.25%. Compositional analysis suggests that the TCP phase is likely the μ phase. Equilibrium phase diagram calculations confirm the precipitation of the μ phase in the alloy at the experimental temperatures， and TTT curve calculations indicate that the time required to precipitate the same volume fraction of μ phase is longer at 900 ℃ compared to 1050 ℃.

This study investigates the influence and underlying microstructural mechanisms of electrospun polyetherimide （PEI） nanofiber membranes on the interlaminar toughness and in-plane mechanical properties of vacuum-assisted resin infusion （VARI） process molded carbon fiber/epoxy （CF/EP） composites. It is founded that PEI nanofiber membranes exhibit good wettability with epoxy resin and do not impede resin flow. PEI nanofiber membranes are suitable for the VARI process under the conditions of a 70 ℃ resin infusion temperature and infusion time less than 30 min. Furthermore， they are dissolved completely within 6 minutes at the resin curing temperature of 120 ℃. Incorporation of PEI nanofiber membranes enhances the interlaminar toughness and in-plane mechanical properties of CF/EP composites. Interleaving 15 g/m² PEI nanofiber membrane in CF/EP composites increases the mode Ⅰ interlaminar fracture toughness， mode Ⅱ interlaminar fracture toughness， and interlaminar shear strength by 55.1%， 65.4%， and 12.2%， respectively. Introducting a 20 g/m² PEI nanofiber membrane in CF/EP composites enhances the flexural strength and modulus by 10.6% and 9.3%， respectively. Moreover， adopting a 10 g/m² PEI nanofiber membrane enhances the compression strength and modulus of CF/EP composites by 24.3% and 18.9%， respectively. The in-situ dissolution of PEI nanofiber membranes and the reaction induce phase separation during epoxy resin curing lead to a homogeneous PEI/epoxy resin bi-phase structure in the interlaminar region of CF/EP composites. These structures enhance the resistance to crack propagation and the load transfer capability of the interlaminar resin matrix， probably improvement in interlaminar toughness and in-plane mechanical properties of CF/EP composites.