In this paper, wheat straw cellulose (WSC) was prepared by the alkali treatment method. Using it as the green reinforcing phase and functional monomer, wheat straw modified acrylamid-based composite super absorbent resin was prepared by the aqueous solution polymerization method. The regulation mechanism of the microstructure, thermal stability, mechanical properties and liquid absorption behavior of WSC proportion composite materials was systematically studied. Based on the comprehensive characterization results of XRD, FT-IR, SEM, BET, TGA and mechanical property tests, it was found that the introduction of WSC effectively grafted copolymerized with the polymer matrix, forming a highly amorphous three-dimensional porous network structure with pore sizes of 1-3 μm. The 15%WSC sample demonstrated outstanding comprehensive performance. Its T_5% was at 248 ℃, with a carbon residue rate of 41.08% at 800 ℃, tensile strength of 90.1 MPa, Young’s modulus of 1 225 MPa, and elongation at break of 8.0%. It had the best thermal stability and mechanical properties. The equilibrium absorbance ratio of this sample in deionized water was as high as 822 g/g, and it demonstrated excellent stability and adaptability in a wide temperature range (25-65 ℃) and a wide pH range (2-12). This research provides a solid theoretical basis and practical solution for the development of high-performance and environmentally friendly biomass-based superabsorbent materials.

Phase change heat storage is the accumulation and release of heat through reversible state changes, and the heat transfer efficiency between high and low temperature media and phase change materials is one of the key factors affecting its heat storage effect. PCMs have good temperature control and high energy storage density in their phase change temperature range, but they generally face the challenge of insufficient thermal conductivity, so they need to be optimized by heat transfer enhancement technology. Based on the types and characteristics of phase change materials and their heat transfer mechanisms, this paper introduces several single heat transfer enhancement technologies such as fins, heat pipes, nanoparticles and porous materials, and also analyzes the combined heat transfer enhancement technologies of heat pipes and fins, heat pipes and porous materials, fins and nanoparticles, fins and porous materials, and nanoparticles and porous materials. The research status of cascade heat transfer enhancement and convective heat transfer enhancement is analyzed, and as well as the unique advantages of these heat transfer enhancement methods in improving heat storage performance. Finally, the limitations of phase change heat transfer enhancement technology are summarized, and its future application potential is prospected, emphasizing the need to combine theory and practice to optimize the performance of phase change heat storage system in tmic benefits.

This paper presents a comprehensive review of the progress in the preparation, performance regulation and application of hafnium oxide (HfO₂) ferroelectric thin films, which have shown broad application prospects in the field of electronic devices due to their unique physical and chemical properties. The article introduces a variety of preparation methods in detail, and analyzes the characteristics and applicable scenarios of each method. The influence mechanisms of doping elements, film thickness, preparation process, and oxygen vacancies on the ferroelectric properties of HfO₂ thin films are further discussed, and the strategies to optimize the properties by regulating these factors are elaborated. Finally, the wide range of applications of HfO₂ thin films in the fields of microelectronics, optics, energy and biology are summarized, demonstrating their potentials in non-volatile memory, transparent ferroelectric materials, high-performance sensors and biomedical devices.

Polyvinyl butyral (PVB) has good compatibility with other additives, strong dimensional stability, and high tensile strength, making it widely used in the batching process of multilayer ceramic capacitors (MLCC). This article investigates the effects of three different molecular weights of PVB on the viscosity of binder and ceramic slurries, the tensile strength of binder sheets and ceramic films, the dispersibility of ceramic slurries, the microstructure of green films, and the electrical properties of MLCC. Experiments have shown that when the PVB molecular weight increases from 53 000 and 95 000 to 110 000, the viscosity of binder increases by 37.70% and 150.00%, respectively. The viscosity of the ceramic slurry increases by 43.97% and 69.85%, respectively. The tensile strength of the green film increases by 26.38% and 52.08%, respectively. Furthermore, a thorough analysis is conducted on the mechanism of changes in viscosity and tensile strength. When the PVB molecular weight is 95 000, a flat and dense green film is obtained, and the MLCC prepared has excellent electrical properties. When the molecular weight of PVB increases to 110 000, the difficulty of batching process increases due to the high viscosity of the binder. Therefore, it is more reasonable to use a molecular weight type of 95 000 when casting a film with a thickness of about 20 μm.

With the rapid development of electric vehicles and energy storage systems, lithium iron phosphate (LiFePO₄, LFP) batteries are widely used due to their excellent safety, stability, and long cycle life. However, with the extension of usage time, LFP batteries have gradually exposed failure problems in actual use, which not only affect the performance of the battery, but also bring new challenges to the recycling and reuse of the battery. The existing LFP battery regeneration technology can be roughly divided into echelon use, pre-treatment, and chemical regeneration. Pre-treatment includes discharge, disassembly and physical separation, while chemical regeneration includes solid-phase repair, liquid-phase recovery, and direct regeneration. Solid phase and liquid-phase methods have their own advantages in wastewater treatment, thermal energy consumption, recovery process, environmental protection, and progress space. This review aims to summarize the field of recycling and repair of retired lithium iron phosphate batteries, summarize the assessment methods of batteries state of health (SOH) in cascade utilization, explain the physical sorting principles in pretreatment, evaluate common recycling and repair methods and economic benefits, and provide a basis for the future recycling industry. Future research should focus on further exploring process optimization, and the development of recycling and repair technologies should explore more efficient and low-cost recycling processes. With the continuous progress of technology and the increase in market demand, the recycling and reuse of LFP batteries show broad application prospects, promoting the sustainable development of the battery industry.

Materials with a light absorption rate greater than 97% are commonly referred to as ultra-black materials. Due to their excellent light-absorbing properties, ultra-black materials demonstrate broad application prospects in fields such as precision optics, solar energy harvesting, infrared thermal detection, and military camouflage. In addition to their intrinsic black properties, ultra-black materials also feature finely designed surface microstructures to achieve ultra-black levels, both of which are essential components of ultra-black materials. This article categorizes the different materials in the current ultra-black field into metal-based ultra-black, biomass-based ultra-black, carbon-based ultra-black, and polymer-based ultra-black materials. The preparation methods, structural designs, and performance characterization of these four types of ultra-black materials are outlined, alongside a summary of their advantages and disadvantages. Finally, the practical applications and future development of ultra-black materials are discussed.

The spent lithium iron phosphate (LFP) powder was loaded on graphite felt (GF) as the anode, and a graphite sheet was used as the cathode. The lithium in the cathode material of spent LFP batteries was leached by an electrochemical method. The effects of five factors, namely voltage, LFP loading, pH, reaction temperature, and electrolyte concentration, on the lithium leaching efficiency were explored in detail using the control variable method. Moreover, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and other analytical techniques were employed to characterize the morphology, structure, elemental composition, and valence state changes of LFP during the leaching process, and its physicochemical properties and the leaching mechanism were analyzed in depth. The analysis of the apparent leaching kinetics indicated that the leaching process was initially controlled by surface chemical reactions (R²=0.988), and after 1 h of the leaching reaction, it was controlled by the diffusion of Li⁺ (R²=0.995). The results demonstrated that, without adding any acid solution or oxidant, this study could still achieve the efficient leaching and recovery of Li⁺. The leaching rate of Li⁺ reached 98.27%, the leaching rate of iron ions was less than 0.05%, the recovery rate of Li⁺ was 92.53%, and the purity of the obtained Li₃PO₄ product was 99.6%.

Lithium batteries play a vital role in next-generation energy storage devices, with separators being critical to both battery safety and electrochemical performance. Therefore, it is essential to produce separators with excellent porosity, electrolyte infiltration and thermal stability. This study utilizes cellulose nanofibers as raw material to prepare composite separators through polyethyleneimine crosslinking and in situ silica modification. The separator exhibits excellent porosity (78.2%), electrolyte uptake (346.1%), and lithium ion transference number (0.69). Batteries assembled with LiFePO₄ as the cathode and lithium metal as the anode have the highest discharge specific capacity (158.4 mAh/g) at 0.5 C and maintain a discharge specific capacity of 99.6 mAh/g at 5 C, demonstrating excellent interfacial compatibility and cycling stability.

As for microelectronics, low-temperature curable polyimide(LPI) is highly desirable. Introducing low-temperature curable accelerators is one of the effective ways to promote cyclization. Among these methods, the curing catalyst units in the main chain can endow PI with high dimensional thermal stability, but it may influence the cyclization of poly(amic acid) due to the steric hindrance effect between adjacent polymer chains.Herein, we incorporate isoquinoline-based amines into PI main chains to afford low-temperature curable PIs with high dimensional thermal stability. In this paper, LPIs with high dimensional thermal stability were obtained by preparing monomers containing an isoquinoline structure and immobilising basic groups inside the molecular chains. In contrast to the reference PI ODA-PMDA, isoquinoline-based PIs can reach high imidization degree at low curing temperature of 200 ℃. Attributed to the stronger basicity of isoquinoline and the smaller steric hindrance effect when catalyzing the adjacent poly(amic acid) chains, isoquinoline-based polymers exhibit stronger catalytic activity. In addition, the isoquinoline-based molecular chains can form intermolecular hydrogen bonds with adjacent molecular chains, leading to more regular chain packing structure. Thus, low CTE of 14.1 ppm/K -15.8 ppm/K in the range of 50 ℃ to 200 ℃ is achieved.

Electrochemical devices such as fuel cells and flow batteries offer promising solutions for addressing global energy and environmental challenges. However, high-performance proton exchange membrane (PEM) remains a critical technical challenge impeding the progress of these devices. Traditional perfluorosulfonic acid membranes (PFSA) have been commercialized but are hindered by high costs and inadequate stability. Sulfonated polyimides (SPI) have become a research focus due to their excellent thermal stability, mechanical strength, and adjustable proton conductivity. Therefore, this review systematically summarizes the structure, proton conduction mechanisms, and preparation methods of SPI, with a focus on its recent advancements of monomer optimization, chain branching/crosslinking and composite modification. It aims to further advance the structural design and applications of SPI.

With the increasing global energy demand and worsening environmental pollution, hydrogen energy has emerged as a promising clean and renewable alternative. Traditional hydrogen production methods rely on fossil fuels and are accompanied by high carbon emissions. Although hydrogen production through electrolysis of water is environmentally friendly, it is limited by the scarcity of fresh water resources. Seawater electrolysis has become an alternative solution due to its abundant resources, but it faces challenges such as slow reaction kinetics, competitive side reactions and electrode corrosion. Among them, the oxygen evolution reaction (OER) is the efficiency bottleneck, while nickel-iron layered dihydroxide (NiFe-LDH) has become a research hotspot for anode catalysts in seawater electrolysis due to its low cost, high activity and structural adjustability. This paper systematically reviews the preparation methods (such as hydrothermal method and electrodeposition method) and modification strategies (such as intercalation engineering, element doping and heterostructure design) of NiFe-LDH to enhance its catalytic performance and stability, providing theoretical support and direction prospects for promoting the large-scale application of seawater electrolysis hydrogen production technology.

As a typical type-II Weyl semimetal, WTe₂ exhibits distinctive transport behaviors, including non-saturating magnetoresistance, high-temperature phase transitions, high-pressure superconductivity, linear and anisotropic magnetoresistance. Owing to the remarkable quantum properties and promising application prospects, WTe₂ has emerged as a significant subject in condensed matter physics. In this study, we employed a four-terminal method to investigate the dependence of magnetoresistance on temperature, the magnitude and direction magnetic field in the WTe₂. WTe₂ exhibits a remarkable positive magnetoresistance effect, showing a parabolic increase with strengthening magnetic field. This phenomenon is attributed to the strong spin-orbit coupling in WTe₂. Furthermore, WTe₂ exhibits pronounced anisotropic magnetoresistance, originating from its Fermi surface structure comprising two pairs of electron and hole pockets with varying radii and carrier concentrations along different crystallographic directions. This structural anisotropy leads to orientation-dependent effects on carrier transport under magnetic fields. Additionally, the magnetoresistance of WTe₂ shows dependence of temperature, we attribute this phenomenon to thermally induced modifications of carrier scattering mechanisms and Fermi surface geometry. The investigation of magnetoresistance in WTe₂ elucidates the underlying physical mechanisms of its unique topological electronic structure and magnetoresistance effects, establishing fundamental principles for the design of next-generation spintronic devices.

Ru based oxides present high electrocatalytic activity for the oxygen evolution reaction (OER) in acidic media, while commercial RuO₂ demonstrates poor stability since it’s prone to dissolve during the OER process. In this work, we used thiourea as the sulfur source and controlled sulfur content within RuO₂ catalysts through thermochemical methods. Research indicates that the formation of Ru-O-S structure by S doping can effectively improve the activity and stability of RuO₂. Significantly, RuO₂ doped with 1.34% S results in an OER overpotentials of 268 mV at 10 mA/cm² and presents a long-term stability of 50 h. Future studies of Ru-O-S structure show that S can generate high-valent Ru sites through bridging oxygen, which enhances the OER activity.

As a green and efficient advanced oxidation technology, photocatalysis has been extensively studied in the degradation of organic pollutants. However, the rapid recombination of photogenerated carriers in most photocatalytic materials limits their catalytic performance. To enhance catalytic efficiency, the piezoelectric properties of materials have attracted increasing attention. Bismuth(Bi)-based materials, as a novel type of semiconductor catalysts, exhibit both photocatalytic and piezoelectric catalytic activities, enabling the coupling of solar and mechanical energy to promote the degradation of organic pollutants. Nevertheless, there remain significant gaps in the design and application of Bi-based piezoelectric-photocatalytic materials. This article reviews the composition of piezo-photocatalytic systems and the fundamental mechanisms for improving catalytic performance, while exploring strategies to enhance the properties of Bi-based piezoelectric-photocatalytic materials, e.g., elemental doping, morphology control, and heterojunction construction. In light of current challenges and future prospects in piezo-photocatalytic technology, the potential applications of Bi-based photocatalytic materials in environmental and energy fields are also discussed.

The instability of Cu⁺ active species in copper-based electrocatalysts leads to decreased selectivity for C₂₊ products, particularly ethylene, during the electrocatalytic CO₂ reduction reaction (CO₂RR). In this study, by introducing rare earth element cerium (Ce), the bimetallic CuCeBTC metal organic framework (MOF) was used as the precursor, and its derived oxide catalyst (CuCeO_x) was prepared by calcination at 350°C. The catalyst was systematically characterized and its electrochemical performance was evaluated. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of Cu⁺ species and mixed valence state of cerium (Ce³⁺/Ce⁴⁺) in the CuCeO_x-2 catalyst with the optimal Ce doping amount. The electrochemical performance tests show that the ethylene Faraday efficiency (FE) of CuCeO_x-2 can reach 45.5% at -1.3 V (vs. RHE), which is significantly improved by 50% compared with the undoped CuO_x catalyst (FE_C2H4 = 30.3%), and the stability can be maintained for more than 12 h. Studies have shown that cerium doping can effectively stabilize the active Cu⁺ species and optimize the electronic structure of the catalyst through the electron buffering effect of Ce³⁺/Ce⁴⁺ redox pairs, enhance the adsorption of the key intermediate *CO, and promote the C—C coupling reaction, thereby significantly improving ethylene selectivity. This study provides a new idea for the design of efficient and stable CO₂RR catalysts.

In this work, a new flame-retardant sodium-ion electrolyte and its stabilization mechanism in sodium-ion batteries were investigated. We introduced dimethyl acetal (DA) into the conventional flame-retardant electrolyte system of trimethyl phosphate (TMP). While maintaining the inherent flame-retardant properties of the electrolyte, the adverse effects of TMP on the cycling performance of hard carbon anode materials were mitigated. Compared with the electrochemical performance of the electrolyte without DA (ETP), the electrolyte with DA (EDT) improved the electrochemical performance of the battery significantly. Furthermore, based on the multi-scale characterization techniques and other electrochemical tests, the electrochemical performance and post-cycling SEI film composition of hard carbon half-cells and full-cells using EDT and ETP electrolytes were comparatively analyzed. And the results showed that the hard carbon half-cells using EDT electrolyte could still offer a discharge specific capacity of 300 mAh/g after cycling for 150 cycles at 0.2 C (1 C=300 Ma/g), and the cycling performance was significantly better than that with the ETP electrolyte. In addition, the HC‖NVP full cell with EDT electrolyte showed a discharge specific capacity of 100 m Ah/g (based on NVP cathode) for 100 cycles with no capacity degradation at a current density of 20 Ma/g, and the capacity retention rate was more than 80% for 500 cycles at higher current density of 100 Ma/g, which proved the feasibility of the new EDT electrolyte improving the performance of the sodium-ion batteries. The new flame-retardant electrolyte designed in this paper can promote the development and application of organic sodium-ion batteries.

With the continuous increase in power density of high-performance computing chips, traditional heat dissipation technologies are facing severe challenges. Aiming at the heat dissipation requirements of high-power density chips, this paper investigates the thermal characteristics of diamond-composite copper heat sinks in single-phase immersion cooling systems using numerical simulation methods. By establishing a three-dimensional fluid-solid coupling heat transfer model, the influence of diamond wafer diameter on heat dissipation performance is systematically analyzed. The research results show that increasing the diameter of the diamond wafer significantly improves the temperature uniformity at the bottom of the heat sink. When the diameter increases from 51 mm to 78 mm, the average temperature of the heat source surface decreases by 3.01 K, and the temperature NU (Non-Uniformity) stabilizes at 1.79%. The high thermal conductivity of the diamond wafer significantly enhances the heat transfer capacity of the system. The decrease in heat sink efficiency with the increase in diamond wafer diameter reflects the improvement of the system's heat dissipation potential, and the Nusselt number increases by 14.4% with the increase in diameter. The total thermal resistance of the heat sink decreases with the increase in diamond wafer size, reaching 0.064 K/W when the diameter is 78 mm. This study provides important design references for the thermal management of high-power density electronic devices.

Thermal oxidative aging of asphalt pavement is an important factor affecting its service life. To investigate the degradation of road performance of different asphalt mixtures after aging, this paper conducted short-term and long-term aging tests on 70# and 90# asphalt mixtures, respectively. The relationship between the viscoelasticity and temperature frequency of asphalt mixtures after thermal oxidative aging was analyzed through dynamic modulus tests, indirect tensile creep tests, and crack propagation tests, and their response to deformation and anti-cracking performance under different temperature conditions were evaluated. The results showed that with the deepening of aging degree, the dynamic modulus of asphalt mixture in the high-frequency range increased by an average of 15%, and the phase angle at medium and low temperatures decreased by an average of about 20%. Its anti-rutting ability was significantly weakened. After long-term aging, the rutting factor of 70# asphalt mixture increased by about 60%, while that of 90# asphalt mixture increased by about 57%, indicating that the high-temperature stability of 90# asphalt mixture was poor and its ability to resist deformation at low temperatures was stronger. Research can provide a basis for preventing thermal oxidative aging of asphalt pavement and improving pavement durability.

As a pivotal catalytic technology, electrocatalysis has demonstrated tremendous potential across energy, environment, and chemical engineering domains. The development of stable, efficient, and cost-effective electrocatalysts constitutes one of the central challenges in this field. Transition metal molybdate electrocatalysts have recently emerged as a promising class of materials owing to their unique physicochemical properties, including abundant catalytically active sites and exceptional structural stability. This review systematically summarizes recent advancements in transition metal molybdate-based electrocatalysts, with particular emphasis on their performance metrics and mechanistic insights in key electrocatalytic processes, hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and carbon dioxide reduction reaction (CO₂RR). A critical analysis of current challenges, including insufficient activity under industrial conditions and long-term durability concerns, is presented through comprehensive structure-activity correlations. Finally, the future research directions and development trends in this field are envisioned, aiming to provide a comprehensive reference for the further research and application of transition metal molybdate electrocatalysts.

In this paper, MOF-derived TiO₂/C composites were prepared by calcination under argon atmosphere using MIL-125(Ti) as a precursor, which successfully retained the porous carbon skeleton (specific surface area of 192.14 m²/g) and formed the Ti—O—C interfacial bonds (XPS showed C—O peak shifted by 0.3-0.5 eV) and oxygen vacancies (O 1s 531.46 eV defect peak in O 1s). The synergistic effect of the carbon skeleton and oxygen vacancies narrowed the band gap to 3.01 eV, which significantly broadened the photoresponse range. Photoelectronic tests showed enhanced carrier separation efficiency (photocurrent density of 24.74 μA/cm², a 40% increase over P25) and reduced charge transfer resistance. In photocatalytic CO₂ reduction, the material achieved a CO yield of 434.12 μmol/(g·h) (12-fold enhancement over P25) and selectively favored the CO pathway (96.09 μmol/(g·h) yield of CH₄). The mechanism study shows that the heterojunction of anatase/rutile mixed phase drives electron migration, the Ti—O—C bond mediates charge transfer to enrich the carbon skeleton with electrons to activate CO₂, and the oxygen vacancies inhibit carrier complexation and optimize the reaction pathway, which synergistically form the synergistic mechanism of “carbon skeleton-oxygen vacancies-Ti—O—C”, and provide a new paradigm for the design of high-efficiency MOF-derived photocatalysts.

At present, AlNiCo material has been widely studied as a permanent magnet material with excellent temperature stability, but the coercivity and maximum magnetic energy product of AlNiCo are far lower than the theoretical value. The coercivity of AlNiCo prepared by directional solidification casting process is 143.31 kA/m, and the maximum magnetic energy product is greater than 79.62 kA/m³. In this paper, the mechanism of amplitude modulation decomposition, coercivity and temperature stability controls of AlNiCo permanent magnets are described. Then the recent research progress, including composition regulation, composite materials, SPS, additive manufacturing methods are introduced. The sintered magnet with applied stress obtained an oriented structure. The maximum coercivity of 161.62 kA/m and remanence of 0.9 T can be achieved by the additive manufacturing process. The further improvement of magnetic performance indicators such as coercivity will greatly improve the accuracy of inertial instruments and promote the development of national defense science and technology fields such as aviation and navigation.

To further enhance the low-temperature performance of high-viscosity asphalt in cold regions pavement and improve the pavement performance of its mixtures, this study introduced 10%, 12%, 14%, and 16% HVA high-viscosity additives into base asphalt to prepare high-viscosity modified asphalt. The fundamental properties were evaluated using three major performance indices and Brookfield viscosity tests, while low-temperature creep and stress relaxation tests were conducted to assess low-temperature rheological characteristics. Meanwhile, rutting, small-beam bending, and freeze-thaw splitting tests were performed to comprehensively evaluate the pavement performance of porous asphalt mixtures. The results indicate that incorporating HVA effectively improves the high-temperature shear resistance of asphalt. As HVA content increases, asphalt creep stiffness rises, creep rate decreases, and low-temperature cracking resistance is enhanced. HVA also reduces shear stress and improves the asphalt's stress relaxation capacity under low temperatures. However, excessive HVA content adversely affects the asphalt's low-temperature performance, with 14% identified as the optimal dosage. The OGFC-13 mixture produced using HVA-modified asphalt exhibits excellent high-temperature stability and water stability, and its flexural tensile strength and bending failure strain both surpass those of SBS-modified asphalt mixtures, demonstrating superior low-temperature cracking resistance.

With the rapid advancement of economy and technology, the demands for coatings have become increasingly stringent. Black coatings, characterized by their high absorption and emission rates, play a pivotal role in fields such as aerospace and precision equipment. This paper reviews the types of common black coatings as well as the advantages and disadvantages of their preparation methods. Black coatings can be categorized into two main types, metal-based composite coatings and carbon nanotube composite coatings. While carbon nanotube composite coatings exhibit excellent light absorption capabilities, their wear resistance is relatively poor. In contrast, metal-based composite coatings demonstrate superior overall performance and are more widely applicable. The methods for preparing metal-based composite coatings include electrodeposition, chemical deposition, spraying, and micro-arc oxidation. Among these, electrodeposition stands out as an excellent method due to its ability to control coating structure by adjusting process parameters, thereby enhancing coating performance. Additionally, electrodeposition is simple and environmentally friendly. The fundamental properties of black coatings are high light absorption and thermal radiation performance. However, current coating performance falls short of meeting the growing application demands, representing a significant research bottleneck. Factors influencing coating performance primarily include the process parameters, the electrolyte composition, and the coating structure. This article summarizes commonly used black coatings, their preparation methods, and the factors affecting their performance, aiming to improve their overall performance. Finally, the paper outlines future directions for black coatings, including continuous enhancement of absorption and emission rates, improved durability, and the expansion of application scenarios.

Multi-component solid waste was used to prepare ultrafine mineral admixtures. The effects of different grinding fineness on the fluidity and activity of multi-component solid waste admixtures were analyzed. The optimal ratio of raw materials was determined by orthogonal test, and the mechanism of action was analyzed using X-ray diffraction (XRD), thermogravimetry-differential thermogravimetry (TG-DTG), and scanning electron microscopy (SEM) for microscopic morphology characterization. The results showed that the superfine composite mineral admixture with excellent performance can be prepared by using 35% slag, 39% water-quenching manganese slag, 20% steel slag and 6% desulfurized gypsum, adding 0.3% grinding activator to the specific surface area of 735 m²/kg. The test results showed that the fluidity ratio of cement sand can reach 99%, the activity index of 7 d can reach 89.2%, and the activity index of 28 d can reach 108%. The addition of ultrafine composite mineral admixtures can reduce the chloride ion permeability, hydration heat release rate and hydration heat release rate of cement-based materials. The research results provided a reference for the preparation of high quality mineral admixtures with multi-component solid waste, and have guiding significance for the utilization of low activity solid waste with high added value.

Addressing the challenge of balancing flame retardancy and mechanical properties in carbon fiber reinforced epoxy resin composites, this study utilized a combination of the reactive flame retardant dicyandiamide modified by 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-DICY) and the additive flame retardant dimethyl methylphosphonate (DMMP) to fabricate a series of flame-retardant carbon fiber/epoxy resin composites. The effects of the blending ratio of these flame retardants on the composite properties were systematically investigated through vertical burning tests, dynamic mechanical analysis, thermogravimetric analysis, and mechanical property testing. The results demonstrate that when the DMMP content was 12 phr and the DOPO-DICY content was 15 phr, a significant synergistic effect between DOPO-DICY and DMMP substantially enhanced the compactness and thermal stability of the char layer. This effectively suppressed the wick effect and enabled the composite to achieve the UL94 V-0 fire rating. Furthermore, the mechanical property was excellent at this formulation. The flexural strength and interlaminar shear strength were 527 MPa and 35 MPa, respectively, exhibiting decreases of only 7% and 17% compared to the unmodified composite.

To enhance the thermal conductivity of phase change materials (PCMs), address the leakage issue, and improve the thermal management capability of photovoltaic/thermal (PV/T) integrated systems, this study prepared a binary PCM using polyethylene glycol 2000 (PEG-2000) and capric alcohol (CP), with an optimal mass ratio of 3∶7 deter mined. Subsequently, graphene (GR) was incorporated to further improve the performance, resulting in the preparation of a PEG-2000-CP/GR composite PCM. The compatibility, thermal properties, adsorption capacity, and stability of the composite PCM were evaluated. The experimental results indicate that there are only physical interactions among the components of the composite material, with no chemical reactions occurring. After adding 15 wt% GR, the thermal conductivity of the composite material increases to 1.6313 W/(m·K), which is 11.5 times higher than that of the binary material. The latent heat of phase change reaches as high as 189.4 kJ/kg. The leakage rate during the phase change process is controlled within 4%, demonstrating good adsorption capacity. After 100 thermal cycling tests, the enthalpy decay rate is only 3%, and the thermal conductivity remains at 83.5% of its initial value, indicating high cycling stability. This study develops a composite PCM with excellent performance, which offers significant improvements in thermal conductivity, heat storage density, and service life compared to traditional PCMs. It provides a basis for optimizing PV/T systems and holds important application value.

The 6××× series (Al-Mg-Si) aluminum alloys are pivotal materials for replacing copper conductors in power transmission and new energy vehicles. However, the inherent trade-off between their strength and electrical conductivity presents a significant research challenge. This review systematically summarizes recent advances in enhancing the overall performance of these alloys through composition design, heat treatment, and deformation processing. It critically examines the decisive role of the Mg/Si ratio on precipitation behavior and the synergistic mechanisms of microalloying elements such as Cu, Mn, Cr, Sc, Zr, and La. The regulation of microstructure and properties by conventional homogenization-solution-aging treatments, combined with novel processes like cryogenic treatment and severe plastic deformation, is also analyzed. Finally, the review outlines existing challenges in synergistic optimization and industrial application, proposing future research directions focused on multi-scale microstructure design to achieve breakthrough performance.

Hydrogen (H₂), as a clean energy carrier, is considered a candidate for the next generation of energy. Hydrogen-oxygen fuel cells convert hydrogen (H₂) and oxygen (O₂) chemical energy into electrical energy, among which the precious metal Pt is considered to be the best electrode material due to its good catalytic performance, but their scarce resources and high price (US$963.58/oz) directly limit their large-scale practical application. Based on this, Ruthenium (Ru) was successfully prepared by hydrothermal method by loading ruthenium (Ru) on carbon nanotube (CNT). Firstly, the surface morphology and valence structure of the catalyst were characterized by transmission electron microscopy(TEM) and X-ray photoelectron spectroscopy(XPS), respectively. Then, a detailed investigation of the electrocatalytic hydroxide performance was carried out in 0.1 M KOH electrolyte. Electrochemical test data shows that the hydrogen oxidation reaction (HOR) performance of Ru-CNT catalyst is superior to that of commercial 20% Pt/C catalyst: at an overpotential of 50 mV, the kinetic current density of Ru-CNT catalyst can reach 14.49 mA/cm² (commercial 20% Pt is 5.05 mA/cm²), and the apparent exchange current density is 1.59 mA/cm² (commercial 20% Pt is 1.34 mA/cm²), and after a 12 000 s stability test, it still maintains high catalytic activity.

Piezoelectric nylon materials exhibit excellent flexibility, mechanical stability, and high-temperature stability, exhibiting broad application prospects in numerous fields such as transducers, sensors, and energy-harvesting devices. Nevertheless, nylon materials have a relatively low piezoelectric coefficient, and their piezoelectric mechanism is still unclear. This restricts their large-scale applications. Therefore, there are many ways to regulate the piezoelectric coefficient of nylon, and then clarify the working mechanism of piezoelectric nylon. This paper first analyzes the piezoelectric mechanism of nylon materials and summarizes different types of methods for regulating the structure and properties of piezoelectric nylon materials, among which electrospinning methods are extensively studied. Finally, this paper summarizes the applications of piezoelectric nylon materials and outlines the prospects of its research direction in the future.

This experiment used fly ash as the raw material and hydrogen peroxide as the foaming agent to prepare fly ash-based polymer lightweight thermal insulation materials. Through single-factor and orthogonal experiments, the effects of activator modulus, liquid-solid ratio, foaming agent dosage, mixing time, and mixing speed on the major performance indicators of lightweight insulation materials, such as compressive strength, apparent density, and thermal conductivity, were explored. The results showed that with the increase of foaming agent dosage and activator modulus, the apparent density, compressive strength, and thermal conductivity of the lightweight insulating material gradually decreased, while they increased with the improvement of mixing speed and time. The order of influence was mixing time > mixing speed > activator modulus. Under the optimal preparation conditions of activator modulus 1.4, mixing speed 600 r/min, mixing time 7 min, liquid-solid ratio 0.45, and foaming agent dosage 7%, adding 1% polypropylene fibers to optimize compressive strength resulted in a final material with apparent density of 0.18 g/cm³, compressive strength of 0.35 MPa (28 d), and thermal conductivity of 0.050 W/(m·K), meeting the Type I standard (cement-based foam insulation board GB/T 2200-2013) for building exterior wall lightweight insulation materials. This study provides theoretical support for the high-value utilization of fly ash in preparing lightweight insulating materials.

This paper mainly summarizes the research on the factors influencing the microstructure and properties of aluminum bronze, which are preparation methods, heat treatment processes and microalloying, aiming to provide certain guidance and reference for determining the optimal alloy composition of aluminum bronze and formulating the best heat treatment process. It elaborates on the effects of various preparation methods, heat treatment process parameters, and different trace alloying elements on the microstructure (such as α phase, β phase, γ₂ phase, and κ phase) and properties (such as strength, hardness, elongation, wear resistance, and corrosion resistance) of aluminum bronze alloys. The results show that the main heat treatment process for aluminum bronze is solution aging treatment, which can significantly improve the mechanical properties of aluminum bronze alloys, and the selection of appropriate process parameters is also extremely important. Adding appropriate amounts of alloying elements such as Ni, Ti, Mn, and Cr can significantly improve the mechanical properties, corrosion resistance, and processing performance of aluminum bronze alloys through optimizing phase composition, strengthening the matrix, and improving interface performance. Finally, the future development of aluminum bronze is prospected.

Geopolymer, a novel type of green cementitious material, holds the significant importance for the comprehensive utilization of bulk industrial solid waste and the reduction of using of energy-intensitive, carbon-emissive cement cementitious materials. The microscopic molecular models of materials, constructed based on Newtonian mechanics and powerful computer modeling, can fundamentally describe the motion of molecules or atoms, facilitating a complete insight of the properties of atoms or molecules within the system and their interactions. This paper reviews recent advancement of constructing and optimizing of models in the molecular dynamics simulation of geopolymers, introduces simulation calculations of their microstructures such as radial distribution functions, bond lengths, and bond angles, as well as application examples analyzing and predicting macroscopic properties including mechanical, thermodynamic, and dynamic behaviors, and microscopic properties such as ions diffusion and interfacial bonding. The development directions of the molecular dynamics simulation of geopolymers, including developing specialized force fields tailored for geopolymer simulations, creating more diverse molecular dynamics models suitable for complex geopolymer systems to conduct in-depth research on the relationship between microstructure and macroscopic properties, and performing the simulation calculations under extreme conditions and complex environments involving multi-physics coupling, are proposed.

The rapid capacity decay and poor rate performance of sodium-ion batteries (NIBs) and lithium-ion batteries (LIBs) remain persisting challenges in energy storage technology. Recent studies have highlighted the critical role of oxygen vacancies (OVs) in improving the electrochemical performance of cathode materials for both battery systems. By enhancing ion diffusion kinetics, reducing charge transfer resistance, and optimizing structural stability, OVs significantly contribute to achieving higher specific capacities and superior rate capabilities. This review summarizes recent advances in the design and application of oxygen-deficient cathode materials for NIBs and LIBs, with a focus on strategies for introducing OVs and their subsequent effects on material structure and electrochemical behavior. Key synthesis approaches, including chemical reduction, doping, and controlled calcination, are discussed as effective methods for generating OVs in transition metal oxide cathodes. Experimental evidence demonstrates that OVs can mitigate phase transitions, stabilize lattice frameworks, and facilitate reversible anion redox reactions. Furthermore, the presence of OVs has been shown to improve electronic conductivity and reduce ion diffusion barriers, leading to enhanced cycling stability and rate performance. However, challenges such as the precise control of OV concentration, long-term stability of vacancy-rich structures, and scalability of synthesis methods require further investigation. This work also addresses unresolved issues related to the quantification of OV contributions to capacity mechanisms and the potential trade-offs between vacancy-induced performance improvements and material degradation. By systematically analyzing the structure-property relationships mediated by OVs, this review aims to provide fundamental insights into the rational design of advanced cathode materials, thereby guiding future research toward high-performance and cost-effective energy storage systems.

Passive radiative cooling (PRC) can radiate heat into ultra-cold outer space (about 3 K) through the atmospheric transparent windows, achieving self-cooling of objects without greenhouse gas emissions or external energy input. This PRC technology can be applied in various fields such as architecture, textiles, smart wearables, electronic devices, and artificial intelligence, which is of significant importance in energy conservation and promoting the achievement of "peak carbon dioxide emissions and carbon neutrality" targets. PRC aerogels integrate high solar reflectance, high infrared emissivity, and high thermal insulation properties, which can significantly reduce the energy consumption load of cooling equipment such as air conditioners and reduce carbon emissions. Starting from the basic principles of thermal radiation and radiative cooling, this article briefly reviews the research progress of PRC materials, focusing on the preparation, properties, and applications of aerogel-based PRC materials. Finally, the future development of PRC aerogels is prospected.

A biodegradable PLA-PBS blends was prepared by melt blending with polylactic acid (PLA) as the main phase and polybutylene succinate (PBS) as the reinforcing phase. The influence of PBS proportion on the microstructure, thermal stability, mechanical properties and degradation performance of PLA-PBS blends was studied. The results showed that the PLA-PBS phases prepared by melt blending didn't form eutectic, but existed in a blended form. As the proportion of PBS increased, the contact angle of the blend decreased, the surface hydrophilicity significantly improved, and the PBS dispersed phase was distributed in the form of spherical droplets. The equilibrium torque of PLA-PBS blend showed a non-linear decreasing trend with the increase of PBS proportion, and the equilibrium torque of 15%PBS sample reached the minimum value of 18.7 N·m, and the formation of dual continuous phases of PLA and PBS made the phase interface reach the optimal state. The 15%PBS sample exhibited the optimal combination of mechanical properties, with a fracture strain increased to 339.5% and a significant increase in fracture strength to 24.4 MPa, which were 31.5% and 79.4% higher than pure PLA, respectively. The maximum tensile strength was 24.9 MPa, and the maximum elongation at break was 330.8%. Its peak impact strength was 7.1 kJ/m², and its bending strength was 87.6 MPa. After adding an appropriate amount of PBS, the degradation rate of PLA-PBS blends was significantly improved. The degradation rate of 15%PBS sample reached 5.3% after 5 weeks of degradation in deionized water, demonstrating excellent environmental friendliness.

With the increasingly stringent performance requirements for cutting tools, molds, and key moving components in high-end manufacturing, traditional hard coatings such as TiN and TiAlN struggle to meet the application demands under extreme working conditions involving high speed, high temperature, and heavy load. Doping with new elements to further enhance coating performance is an effective strategy. Among these, TiAlCrN quaternary nitride coatings have been extensively studied by researchers worldwide due to their excellent hardness, wear resistance, and oxidation resistance. This paper provides a systematic review of the advantages and disadvantages of preparation processes for TiAlCrN hard coatings, analyzes the influence of coating elemental composition on their microstructure, summarizes various strengthening mechanisms of mechanical properties, elucidates the improvement mechanisms of tribological performance and high-temperature oxidation resistance, and further introduces their current application status in fields such as cutting tools and molds. Finally, potential future research directions and development trends in this field are discussed, aiming to provide theoretical references and technical insights for the further design and optimization of high-performance TiAlCrN coatings.

Expanded polystyrene (EPS) particles have advantages such as closed cell structure and lightweight, and have important engineering application value in improving the insulation performance of foam concrete. EPS particle foam concrete was prepared using P·O 42.5 grade cement as the raw material and EPS particles as the additive phase. The effects of EPS particle doping amount on the microstructure, mechanical properties, insulation performance and frost resistance of foam concrete were studied by XRD, SEM, TGA, and salt freezing cycle testing. The results showed that the introduction of EPS particles delayed the hydration process of cement. The addition of EPS particles had little effect on the proportion of harmful pores between 50-200 mm, but effectively reduced the proportion of severe harmful pores above 200 mm. The proportion of severe harmful pores in the EPS9% sample decreased to a minimum of 19.58%, the proportion of harmless pores was the highest at 59.45%, and the proportion of low harmful pores was the highest at 12.95%. The EPS9% sample exhibited the best ductility performance, with a fracture point displacement of 0.41 mm and a maximum fracture energy of 707 N·mm. The thermal insulation performance of foam concrete was improved by adding appropriate amount of EPS particles. The minimum thermal conductivity of the EPS9% sample was 0.066 W/(m·K). With the increased of EPS particle content, the compressive strength of concrete samples first slightly decreased and then slightly increased. After 100 salt freezing cycles, the compressive strength of the EPS9% sample reached a maximum of 24.7 MPa, the lowest mass loss rate was 1.06%, and the maximum relative dynamic elastic modulus was 84.41%. Compared with the EPS0% sample, the mechanical properties and frost resistance were significantly improved.

Carbon fiber is one of the most widely used conductive phases in electrically conductive concrete (EC), yet existing studies lack consistency and systematicity in parameter selection. In this study, the effects of different carbon fiber lengths (3-20 mm) and volume fractions (0.2%-1.8%) on the electrical, mechanical, and electrothermal properties of EC were systematically investigated. Considering practical deicing scenarios, electrical resistivity and electrothermal performance were evaluated under ambient (25 ℃) and low-temperature (-15 ℃) conditions. The results indicate that the resistivity of EC decreases significantly with increasing fiber content, exhibiting a typical percolation effect. When the carbon fiber content reaches 1.2 vol%, the resistivity of EC with different fiber lengths remains consistently below 100 Ω·cm, meeting the requirements for deicing and snow-melting applications. At a fiber length of 8 mm and a content of 1.2 vol%, the flexural and compressive strengths of EC are increased by approximately 79% and 102%, respectively, compared with ordinary concrete. Under a low-voltage (2 V) input, EC demonstrates a rapid temperature rise of about 40 ℃ and maintains stable electrothermal performance at -15 ℃. Considering the combined electrical, mechanical, and electrothermal performance, the optimal mix proportion is identified as 1.2 vol% fiber content with a length of 8-15 mm. These findings provide theoretical and experimental support for the engineering application of carbon fiber EC in cold-region pavement protection and intelligent monitoring.

Valleytronic devices utilizes the electron's valley degree of freedom, combining it with other degrees of freedom such as charge and spin, for information encoding. It holds great potential for application in next-generation electronic devices, which are focused on the advancement of artificial intelligence and the processing of large-scale data. Ferrovalley materials with spontaneous valley polarization provide a convenient method to flexibly manipulate the valley degree of freedom. Moreover, coupling the valley degree of freedom with Berry curvature in such materials can generate the anomalous valley Hall effect, enabling electrical readout of valley states—a crucial factor for the practical application of valleytronic materials. Therefore, this work systematically reviews recent research progress on two-dimensional ferrovalley materials both domestically and internationally. The valley degree of freedom and the Valley Hall Effect (VHE) are first briefly outlined. Then, a systematic classification of ferrovalley materials is performed according to chemical composition, followed by comprehensive analysis of their characteristic properties and modulation strategies, with special attention given to high-efficiency approaches such as external field tuning, strain engineering, and stacking configuration manipulation. Subsequently, the theoretical underpinnings of valley-related phenomena are briefly discussed. Finally, we look forward to the challenges and opportunities in the development of two-dimensional ferrovalley material.

Liquid metals (LM) exhibit exceptional thermal conductivity, electrical conductivity, fluidity, deformability, and significant latent heat of phase change, which positions them as promising candidates in the field of phase change thermal management. However, their strong corrosiveness and poor compatibility with load-bearing materials always lead to leakage and subsequent failure of electronic components, thereby limiting their practical applications. This study utilizes silicon carbide nanowire-modified high thermal conductivity foam graphite (SiCNWs-GF) as a substrate, into which a gallium-tin alloy (GaSn) is incorporated through vacuum impregnation to create a high thermal conductivity phase change composite material. The thermal management characteristics of this composite are investigated. The modified foam graphite demonstrates good compatibility with the liquid metal, and its capillary structure effectively enhances the leakage resistance of the liquid metal. When subjected to a power load of 200 W for 200 s, the surface temperature of the heat sink containing the liquid metal/foam graphite composite is recorded at 34.1 ℃. In contrast, the surface temperature of a heat sink filled with paraffin/foam graphite composite under the same conditions reaches 49.4 ℃. This comparison indicates that the use of the liquid metal/foam graphite phase change composite results in a temperature reduction of 15.3 ℃, thereby demonstrating its superior thermal management properties.