MXenes， with the general formula M {}_{n+\mathrm{1}}^{} X_nT_x， are a novel class 2D nanomaterials composed of transition metallic compounds with nitrogen or carbon. Due to the rich functional groups on its surface， MXenes have been widely used in biosensing， tumor therapy， tracer imaging， and other biological fields. MXenes exhibit strong antibacterial activity and certain active oxygen-scavenging ability， and these biological characteristics closely align with the required properties of wound dressings， making MXenes a popular material for wound dressing modification in recent years. In this review， the structure， properties， and preparation methods of MXenes are introduced in detail， and the latest research progress of MXenes and their composites in the field of wound repair， bone defect repair， and muscle repair are reviewed.

MXene is a graphene-like two-dimensional transition-metal carbide，nitride，or carbonitride nanomaterial，typically exhibiting quasi-metallic or narrow-bandgap semiconductor characteristics. Recently，MXene has garnered significant interest in the photothermal conversion field owing to its remarkable attributes，including outstanding broad-spectrum light absorption performance，ultrahigh specific surface area，varied and adjustable surface functional groups，versatile imaging modes， biocompatibility，low toxicity，and more. This review offers a comprehensive look at the preparation techniques，underlying principles， and surface functional group attributes of MXene， focusing on the latest advancements of MXene，especially the MXene-based composite materials， in the fields of photothermal water evaporation， catalysis， sterilization， and therapy. Besides，leveraging the full-spectrum and near-infrared absorption properties of MXene，this review also delves into the design principles of MXene-based photothermal materials. It explores the synergistic effects of their photothermal effects in the photocatalysis and enzyme catalysis applications. Finally，the challenges and prospects of MXene used in the photothermal field are summarized briefly.

As electronic components become increasingly intelligent， lightweight， and integrated， the power density of electronic equipment increases dramatically. The development of high-performance thermally conductive composites has thus become critically important. One-dimensional polymer nanofibers are conducive to the effective connection of thermally conductive fillers in the axial direction and promote the formation of effective thermal conductivity paths between adjacent thermally conductive fillers. Consequently， when the same content of fillers is added in polymer matrix， these kind of anisotropic composites usually exhibit superior thermal conductivity， which has attracted widespread attention from researchers. This paper systematically summarizes the research progress of polymer nanofiber-based anisotropic thermally conductive composites including cellulose nanofibers， aramid nanofibers， poly-paraphenylene benzobisoxazole nanofibers， and electrospun nanofibers， and discusses the regulation effect of low-dimensional thermally conductive fillers on the properties of polymer nanofiber-based composites. Finally， the challenges and future development directions of nanofiber-based thermally conductive composites are prospected.

CrCoNi-based medium-entropy alloys have garnered substantial research attention as high-performance metallic materials， owing to their exceptional synergy between strength and toughness. This review provides a systematic overview of the core strengthening-toughening mechanisms and pivotal performance-regulation strategies. At the atomic scale， chemical short-range order （CSRO） promotes the formation of locally ordered clusters， which impede dislocation motion. Moreover， the dynamic evolution of CSRO interacts with stacking fault energy， facilitating the generation of stacking faults and deformation twins. On the nanoscale， a three-dimensional twin network not only restricts dislocation glide but also provides channels for slip. Additionally， the introduction of nanoscale precipitates modifies the dominant deformation mechanism， enabling the simultaneous enhancement of strength and ductility. Further research reveals that precise control over heat treatment， additive manufacturing， and plastic deformation processes can effectively tailor strengthening phases and gradient structures， thereby improving mechanical properties. The alloy demonstrates a distinct advantage at cryogenic temperatures， where multiple deformation mechanisms are activated， resulting in the concurrent enhancement of strength and toughness. Future research endeavors should concentrate on elucidating the dominant mechanisms at room temperature and enhancing environmental adaptability to facilitate engineering applications.

Aluminum bronze alloys are widely used in marine industrial fields such as ship propellers， high-pressure pump bodies， and valves due to their excellent mechanical properties， cavitation resistance， and corrosion resistance. However， traditional casting processes have drawbacks in the preparation of aluminum bronze alloys， including long production cycles， high costs， and low part precision， and the as-cast alloys are prone to internal porosity， shrinkage cavities， and surface slag inclusions. As a novel advanced manufacturing technology， laser additive manufacturing enables rapid forming of metal components， and its rapid cooling process facilitates the formation of fine grains， thereby improving alloy performance， demonstrating great potential and broad prospects in the preparation of aluminum bronze alloys. This paper focuses on two processes， selective laser melting and laser melting deposition， introduces the laser additive manufacturing processes for aluminum bronze alloys and the associated challenges， reviews recent research achievements both domestically and internationally on process characteristics， microstructure， and properties， analyzes the main existing problems and research gaps， and finally points out that expanding the variety of aluminum bronze alloy materials for laser additive manufacturing， optimizing laser process parameters， and controlling defects during the forming process are key directions for future research.

The application of laser powder bed fusion （LPBF） on TC4 titanium alloy is an important way to achieve lightweight and integration in aviation， aerospace， medical， electronics，and other fields at present. In this paper， the effects of laser powder bed fusion on microstructure and defects of TC4 titanium alloy and its mechanism are systematically summarized. The research status of the influence of LPBF parameters and heat treatment methods on the tensile properties of TC4 alloy formed by LPBF is reviewed in detail as well. On this basis， in view of the bottleneck on application of LPBF TC4 titanium alloy at the present stage， the research status of fatigue properties and fracture toughness of TC4 alloy formed by LPBF is systematically summarized， and the effective post processing methods to improve the fatigue property and fracture toughness of TC4 titanium alloy fabricated by additive manufacturing are pointed out， and the development trends are also discussed.

Arc heat sources are extensively employed in welding and additive manufacturing， emerging as an indispensable core energy medium for the joining and forming of metal components. Nevertheless， traditional arc heat sources are plagued by inherent flaws， such as the highly-coupled heat and mass transfer behaviors that are difficult to control independently. This results in a profound coupling between the heat input to the workpiece and the wire deposition rate， posing a significant challenge in simultaneously satisfying the dual demands of high-efficiency deposition and high-quality forming. Consequently， it severely restricts the high-performance manufacturing process of large and complex structural components. Therefore， conducting research on the decoupling of heat and mass transfer in arc heat sources is of immense theoretical value and urgent engineering significance for transcending traditional arc manufacturing technology. This paper presents a systematic review of the research progress in the decoupling technology of heat and mass transfer in arc heat sources， with a particular focus on the state-of-the-art cross-arc configuration. From a physical perspective， this technology achieves orthogonal decoupling of heat input and mass transport through the coordinated arrangement of independent heat sources and independent mass sources. The article offers an in-depth examination of key aspects， including the stability control， droplet transfer behavior， and development challenges of cross-arc heat sources. Its objective is to provide a robust theoretical foundation and feasible technical route support for constructing a new generation of intelligent arc manufacturing systems with independent and controllable heat and mass.

In the field of electronic packaging， Au-Sn eutectic alloy （AuSn20） serves as key solder materials， and its preparation process directly affects the packaging performance and reliability. However， due to the brittleness of AuSn20， there is currently no efficient method for the preparation of AuSn20 solder balls. This study uses pulsated orifice ejection method to achieve the high precision and consistency of the on-demand preparation of AuSn20 solder balls. The results show that various specifications of AuSn20 solder balls are prepared under optimal process conditions， with the smallest specification being 50 μm， and the maximum standard deviation of the target particle size being 1.58 μm， significantly improving the preparation accuracy. Microstructural analysis reveals that the solder balls are mainly composed of δ-AuSn and ζ'-Au₅Sn eutectic phases， with no abnormal new phases observed. After reflow treatment， the composition distribution inside the solder ball tends to be uniform.Interface reaction studies show that due to the synergistic diffusion of Ni atoms in the diffusion barrier layer， a complex intermetallic compounds （Au，Ni）Sn and （Au，Ni）₃Sn₂ are formed at the interface joint. The AuSn20 solder balls prepared in this study not only achieve precise control of particle size and consistent thermal history， but also show excellent interface stability and structural integrity under simulated service conditions， opening up new application avenues for Au-Sn alloy brazing materials in advanced electronic packaging.

To solve the problem that the brazing temperature of existing filler metals for joining the superalloy GH4169 exceeds its δ phase solid solution temperature， which leads to the dissolution of the δ phase during brazing and consequently degrades the high-temperature performance of the alloy， this work conducts a study on a novel low-temperature Ni-based brazing filler for GH4169 and optimizes the brazing process. The brazing temperature is set at 980 ℃， which is comparable to the solid solution temperature of the alloy， in order to achieve a good match between brazing and heat treatment temperatures. Based on the binary phase diagrams， with Pd as the primary melting point depressant and B and Si as the secondary melting point depressants， a novel Ni-based brazing filler of 36Pd-10Cr-3B-1Si-Ni is configured and smelted. The melting point， wettability， and weldability of the novel filler on GH4169-GH536 butt joints are investigated. The results show that the solidus and liquidus temperatures of the novel filler are in the range of 828.82-961.43 ℃， and the wetting angle is 7.8°at 980 ℃ for 15 min， demonstrating excellent wettability， thereby optimizing the brazing process parameters. Under the process conditions of 980 ℃ for 60 min and a joint clearance-free assembly， the maximum room-temperature tensile strength of the brazed joint reaches 586 MPa， which exceeds that of the conventional BNi-2 brazing filler； the high-temperature creep rupture performance at high temperature exceeds 10 h， and the joint is free of obvious defects. Therefore， the novel low-melting Ni-based brazing filler of 36Pd-10Cr-3B-1Si-Ni can be used to achieve effective brazing of GH4169 while preserving its original microstructure and properties.

Traditional cemented carbides typically use Co as the binder. In recent years， novel cemented carbides employing high-entropy alloys as substitutes for Co have demonstrated significant advantages in improving hardness， fracture toughness， high-temperature oxidation resistance， and corrosion resistance. In cemented carbides with Cr- and Mo-containing high-entropy alloy binders， the strong carbide-forming elements Cr and Mo influence the carbon content in the binder phase and the existing form of carbon in the alloy， thereby affecting the mechanical properties. This work aims to investigate the influence mechanism of carbon addition on the microstructure and grain growth of WC-CoNiFeCrMo cemented carbides， and to explore the variation patterns of their mechanical properties. The results show that with increasing carbon addition， the WC grain size in the WC-CoNiFeCrMo alloy changes slightly， the coercive force gradually decreases， and the hardness decreases slightly. The fracture toughness and transverse rupture strength of the alloy first increase and then decrease， reaching peak values when the total carbon content of the alloy increases to 5.73%（mass fraction）， with a fracture toughness of 18.52 MPa·m^1/2 and a transverse rupture strength of 2991 MPa. With further increase in carbon addition， carburized phases appear in the alloy， and the fracture toughness and transverse rupture strength decrease significantly.

This study investigates the characteristics and formation mechanisms of pore defects in TC4 titanium alloy fabricated via selective laser melting （SLM） through numerical simulation and industrial computed tomography （CT） analysis. Numerical simulations find that the temperature at the laser beam spot is high， while the temperature away from the laser beam spot is low. After printing， microstructural characterization reveals well-overlapped melt tracks； however， both spherical and irregularly shaped pores are observed within the consolidated material. Using the same parameters as the simulation， the TC4 alloy prepared by SLM has a density of 97.7%. Microstructural analysis shows that the grains along the scanning direction and building direction are equiaxed and columnar crystals， respectively， and the microstructure is composed of primary β-Ti and α'/α-Ti. Metallographic structure， SEM images， and industrial CT reconstruction images demonstrate the presence of spherical and irregular pores in the material that are similar to the numerical simulation results. The appearance of spherical pore defects is due to the vapor pressure difference between the molten pool and the solid metal surface， which causes the gas at the interface to be carried into the molten pool without overflowing， ultimately remaining inside the material； the appearance of irregular pores is due to the uneven temperature distribution that makes it difficult for the pores enclosed inside the material to be completely filled by the liquid phase when the melt track passes over each other.

Selective laser melting （SLM） technology， with its unique solidification characteristics， can overcome the issue of coarse grain size in conventionally cast alloys. To achieve grain refinement and improve the mechanical properties of Cu-Al-Ni alloy prepared by SLM， the effects of key process parameters， including laser power and scanning speed， on the microstructure and mechanical properties perpendicular to and along the building direction are studied. The results show that fully overlapping melt tracks are present perpendicular to the building direction， in contrast， parallel to the building direction， it shows columnar grains that have grown epitaxially layer by layer. Both directions primarily consist of lath martensite. With increasing scanning speed at constant laser power， or with slightly decreasing laser power at fixed scanning speed， the melt tracks become narrower， and both the grains and martensite are refined. At a laser power of 280 W and a scanning speed of 850 mm/s， the resulting alloy exhibits the narrowest melt tracks， the finest grain size and martensitic structure， and the best mechanical properties. The hardness and compression strength measured along the building direction reach 251.2HV and 1465 MPa， respectively， while these perpendicular to the building direction reach 245.7HV and 1189 MPa， respectively. The refinement of grains and martensite is attributed to the high cooling rate inherent to SLM， and the improvement of mechanical properties is mainly due to grain refinement strengthening. The fine columnar grains， dense martensite and presence of twinning along the building direction result in higher interface density， which provides stronger resistance to dislocation slip， thereby leading to superior mechanical properties.

The isothermal oxidation mass gain test is adopted to study the high-temperature oxidation behavior at 800 ℃ of 310S stainless steel prepared by selective laser melting （SLM） and cold rolling （CR）. The microstructure， oxidation kinetics， and oxide scale structure of SLM-310S and CR-310S are systematically analyzed. The results show that both SLM-310S and CR-310S exhibit a single-phase austenite structure. SLM-310S forms a fish-scale structure due to molten pool stacking， characterized by fine and uniform grains， each containing numerous columnar and cellular subgrains. In contrast， CR-310S has typical polygonal austenite grains containing numerous twins. During oxidation at 800 ℃， the mass gain of SLM-310S is lower than that of CR-310S， with oxidation rate constants of 5.612×10^-4 mg²·cm^-4·h^-1 （SLM-310S） and 8.593×10^-4 mg²·cm^-4·h^-1 （CR-310S）， respectively. Both specimens develop a double-layer oxide scale： the scale on SLM-310S is approximately 2-4 μm thick and mainly composes of SiO₂， Cr₂O₃ and MnCr₂O₄， while that on CR-310S additionally contains a small amount of Fe-containing oxides， along with pore defects within the matrix. Owing to its excellent microstructural characteristics， SLM-310S exhibits slower oxidation kinetics and a denser oxide scale， demonstrating superior high-temperature oxidation resistance at 800 ℃ compared to CR-310S.

The friction pairs， such as the valve core and valves of seawater pumps， are under the conditions of seawater corrosion and wear （referred to as “tribocorrosion”）. The tribocorrosion resistance of materials directly affects the service life and safety reliability of marine engineering equipment. In-situ corrosion friction tests are adopted to quantitatively study the corrosion and wear mechanisms of three passivable alloys： titanium alloy （Ti75）， stainless steel （316SS）， and aluminum alloy （5083） in a 3.5%（mass fraction） NaCl aqueous solution. The results show that due to the lubricating effect of the erosion products of Ti75， corrosion and wear have a negative synergy， reducing the amount of wear， while the corrosion and friction of 5083 aluminum alloy and 316SS samples promote each other. The corrosion rate and tribocorrosion rate（2.25×10^-3 mm³/（N·m）） of 5083 aluminum alloy are both the highest， while the tribocorrosion rate of 316 stainless steel （6.78×10^-6 mm³/（N·m）） is the lowest. Among the three materials compared in this article， 316SS is the best material for manufacturing wear-resistant parts in seawater.

To address the functional failure of copper and its alloys caused by surface corrosion，a method combining micro-arc oxidation and silicone oil heat treatment is proposed to construct a long-lasting corrosion-resistant and hydrophobic film layer on the surface of copper-zinc alloys. Firstly，through micro-arc oxidation and doping with ZrO₂ particles，a porous microstructure is constructed in-situ on the surface of copper-zinc alloys，and rigid nanoparticles are introduced. Together with micropores，they form the multi-level micro-nano structure required for a hydrophobic surface. Secondly，the oxide film layer is sealed and modified with a dimethyl silicone oil solution. Finally，the silicone-oil-modified oxide film layer samples are heated under a heat-treatment environment to reduce the surface energy of the oxide film layer and achieve hydrophobicity. The surface morphology，chemical composition，and phase composition of the hydrophobic film layer are characterized by scanning electron microscopy （SEM），energy dispersive spectroscopy （EDS），and X-ray diffraction （XRD），respectively. The wettability，corrosion resistance，and durability of the hydrophobic film layer are tested using a contact angle measuring instrument，an electrochemical workstation，and a tape peeling test，respectively. The results show that the main phases on the surface of the hydrophobic film layer are CuO，ZnO，α-Al₂O₃，γ-Al₂O₃，ZrO₂，and SiO₂. Compared with the copper-zinc alloy substrate，the corrosion current density of the hydrophobic film layer is reduced by four orders of magnitude. The water contact angle increases from the original 64.1° to 139.2°，and the surface adhesion energy decreases from 45.331 mJ/m² to 3.554 mJ/m². After 150 tape peeling tests，the contact angle of the prepared hydrophobic film layer surface is still higher than 120°，maintaining good hydrophobicity. This study can provide certain experimental basis and fundamental guidance for the surface corrosion protection of copper and copper alloys.

TiC particles that can be wetted by iron-based alloys at elevated temperatures act as the hard phase. The TiC/Fe composite coatings featuring alternating hard and soft phases are cladded on the surface of Q235 steel plates to enhance their service life under wear resistant conditions. The results show that the TiC/Fe composite coatings prepared by laser cladding form a composite structure with alternating hard TiC phase and soft γ-Fe phase. However，when the area ratio of the soft phase to the hard phase is large （greater than 1.8），the “high hardness-antifriction” TiC/Fe composite coatings are not obtained. When the area ratio of the soft γ-Fe phase to the hard TiC phase is approximately 1∶1，a “high hardness-antifriction” synergistic effect is achieved，that is，the average hardness of the alloy coatings is as high as 1300.39HV_0.2，and the average coefficient of friction is only 0.1127. The wear mechanism of the iron-based alloy coatings without TiC particles is mixed a wear mechanism of abrasive wear，adhesive wear and oxidative wear. After adding TiC particles，the wear mechanism of the alloy coatings are mainly slight oxidative wear，and with the increase of TiC particles addition，the oxidative wear of the alloy coatings weakens.

To improve the corrosion resistance of waterborne epoxy coating， chitosan is adsorbed onto the surface of multi-walled carbon nanotubes via surface-deposition crosslinking with glutaraldehyde as the crosslinking agent. Then， stearic acid has been grafted using a water-soluble coupling agent，1-ethyl-（3-dimethylaminopropyl）carbodiimide hydrochloride （EDC·HCl），to synthesize stearic acid/chitosan-modified multi-walled carbon nanotubes （SA/CS-CNTs）. Aqueous epoxy anticorrosive coatings are prepared by blending SA/CS-CNTs with aqueous epoxy resin. The structure of SA/CS-CNTs has been characterized， and the corrosion resistance performances of the coatings have been explored. The results show that the epoxy resin with 0.5% （mass fraction）SA/CS-CNTs filler has the best corrosion resistance. Compared with the pure waterborne epoxy coating， its low-frequency impedance modulus is increased by about 5 orders of magnitude， the corrosion inhibition efficiency increases to 99.66%， and the water contact angle reaches 104.2°. The corrosion potential increases by 0.39 V，and the corrosion current density decreases from 4.17×10^-6 A·cm^-2 to 1.44×10^-8 A·cm^-2. After being immersed in 3.5% NaCl solution for 96 h， its impedance modulus is still above 10⁷ Ω·cm².

To tackle the challenges of high-temperature phase stability deterioration and sintering densification in zirconia-based thermal barrier coating ceramic materials during prolonged service at temperatures exceeding 1200 ℃， this study utilizes a highly efficient and cost-effective solid-phase synthesis process to fabricate La₂Zr₂O₇-SYSZ composite ceramics with a hypoeutectic composition. We conduct a comprehensive investigation into the impact of 1450 ℃ heat treatment on the high-temperature microstructural stability， evolution， and grain growth kinetics of these composite ceramics using field emission scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDS）. The experimental findings reveal that La₂Zr₂O₇-SYSZ composite ceramics， sintered at 1600 ℃ for 6 h， display equiaxed or near-equiaxed grain morphology， with an average grain size of （2.9±0.31） μm. Following heat treatment at 1450 ℃ for durations ranging from 50 h to 300 h， the grain size distribution curves exhibit a notable rightward shift and broadening， with the average grain size gradually increasing to （4.7±0.33） μm. Initially， the grain size distribution follows a single-peak normal distribution pattern； however， as the heat treatment time is extended to 150-300 h， it gradually evolves into a dual-peak normal distribution. The composite system demonstrates a grain growth activation energy of （351.79±19.21） kJ/mol and a growth exponent （n=2.3）， suggesting that grain growth is predominantly governed by lattice-diffusion-controlled pinning effects. This research offers vital theoretical underpinnings and technical references for the development of next-generation anti-sintering thermal barrier coating materials.

As a vital successor to conventional oil and gas resources， shale-gas development inevitably generates drilling-cuttings hazardous waste. Finding ways to exhaust and up-value this waste becomes another pressing problem for the industry. In this study， deoiled residue of drilling cuttings （DRDC） is used as the main feedstock， added with low-grade bauxite as supplementary alumina source and potassium feldspar as fluxing agents. A 50 kg/h pilot-scale line installed at the extraction site is operated continuously for 25 days to systematically evaluate how the deoiled residue content and sintering temperature affect the bulk density， apparent density and breakage ratio of the ceramic proppants. The results show that the roundness and sphericity for all proppant products exceed 0.9. Both bulk and apparent densities of the ceramic proppants decreases progressively with increasing addition of the drilling cutting， whereas the breakage ratio rises. Raising the sintering temperature increases the bulk and apparent densities but reduces the breakage ratio. At the preparation parameters including the content of DRDC of 5%（mass fraction） and sintering temperature of 1300 ℃， ceramic proppants with a breakage ratio of 3.01% measured at 52 MPa closure stress can be obtained. Ceramic proppants meeting the standard of SY/T 5108—2014 are produced under all twenty producing conditions.

A method of continuous flash pretreatment combined with oxidative amination grafting is proposed to prepare the cross-linked biobased material which can be hot processed. The effects of thermoforming processing methods， decrosslinking recovery and reprocessing on the properties of the materials are investigated. The results show that when the mass ratio of sodium periodate to plant fiber is 0.3 and the molar ratio of amine to aldehyde is 1.4， the sheet exhibits excellent mechanical properties and good hydrophobicity. The expansion rates of bending strength and water absorption are 58.2 MPa and 15.7%， respectively， and the tensile strength is increased to 69.9 MPa after dynamic molding. The water absorption expansion rate is reduced to 11.2%. The results show that the strength of 3 h， 80 ℃ hydrolyzed products can reach 55.1 MPa and the properties can be maintained to 78.9% after crushing， hydrolyzing， and reforming the dynamic moulded sheets. The results prove the feasibility of oxide-amination modification method and dynamic die molding to prepare high performance plant fiber materials， which is helpful to realize the recycling of plant fiber and the development of environmentally friendly biomass materials.

The effects of two different deformation processes（process 1 and process 2） on the micro-structure and mechanical properties of reduced activation ferrite/martensite （RAFM） steel （Fe-0.21C-11.76Cr-1.41W-0.20V-0.17Ta-0.63Si-0.51Mn-0.015N， mass fraction/%） tubes are studied. The results show that when the rolling deformation of process 1 gradually increases from 44% to 66%， the tubes’ martensitic matrix transforms into fine ferritic matrix， the yield strength（σ _y） increases from 302 MPa to 407 MPa， the elongation（El） decreases from 28.6% to 25.8%， and the tensile strength（σ _U） remains basically unchanged. The matrix microstructure of process 2 （deformation amount 53%-57%） tubes also undergoes the transformation from martensite to ferrite， but due to the relatively small deformation amount， complete recrystallization is delayed， and σ _y decreases from 487 MPa to 364 MPa， and El increases from 23.9% to 36.3%. The tubes of two processes are subjected to the same forward and tempering treatments after final rolling with 44% and 66% deformation respectively. The microstructure of the finished tubes shows that carbide particles are evenly distributed on the matrix of lath martensite， and their mechanical properties at room temperature are equivalent（σ _y=590-597 MPa，σ _U=810-817 MPa，El=20.7%-22.8%）. However， the high-temperature mechanical properties of the finished tubes of process 2 （σ _y=357 MPa，σ _U=380 MPa，El=16.3%） are slightly lower than that of process 1 （σ _y=383 MPa，σ _U=446 MPa，El=21.6%）.

This study addresses the high-temperature sealing challenges in aero-engines by analyzing the effects of wall thickness， compression ratio， and cyclic compression cycles on the elastic performance of U-shaped metal seals. The optimal parameter combination is determined through systematic investigation. Additionally， a dedicated high-temperature gas tightness testing apparatus is developed to evaluate airtight performance， with a derived leakage rate calculation formula providing quantitative analysis. The results demonstrate that the elastic recovery rate decreases with increased wall thickness， higher compression ratios， or greater numbers of compression cycles. At 650 ℃， all three tested wall thicknesses maintain over 90% recovery rate after 50 compression cycles， with the 0.5 mm configuration showing superior elastic characteristics. Leakage rate exhibits negative correlation with temperature and contact stress， while displaying positive linear dependence on pressure differentials. Notably， the 0.5 mm seal achieves 50% lower leakage at 650 ℃ compared to room temperature. Enhanced wall thickness or compression ratio improves airtightness by elevating interfacial contact stress.

A novel auxetic columnar honeycomb structure is introduced， in which four honeycomb structures of identical dimensions are designed by varying the number of unit cells. The effects of unit cell number on the mechanical behaviour and energy absorption performance of the honeycombs are investigated through impact experiments and finite element numerical simulations. The energy absorption performance is compared with the specific absorption energy of aluminum honeycombs of different masses. The results demonstrate that the honeycombs exhibit a unique compression-torsion coupling deformation mechanism during impact. The torsional motion of cell walls redistributes the internal forces， effectively absorbing and dissipating impact energy， thereby improving energy absorption efficiency. Further analysis reveals that the number of unit cells significantly affects the mechanical performance of the honeycombs， enhancing plateau stress and specific energy absorption， although compression displacement decreases. A comprehensive mechanical performance analysis indicates that HM4-8 demonstrates the optimal impact performance and energy absorption efficiency， making it suitable for high-efficiency energy absorption and impact protection applications. This study provides new insights into the optimized design of honeycomb structures， with significant engineering value， especially in fields requiring lightweight designs and high impact resistance.

Nanomaterials with combined photothermal-chemodynamic therapy （PTT-CDT） offer significant advantages in cancer treatment， yet designing and fabricating such multifunctional nanomaterials remains challenging. In this study， cuttlefish ink （M） is used as a core， onto which a layer of CuO is grown， successfully constructing the M@CuO composite multifunctional nanomaterial. The results show that the M@CuO exhibits a spherical shape with a nanoparticle size of 128.2 nm and demonstrates excellent photothermal conversion efficiency （η _T=47.6%） under near-infrared light irradiation. Additionally， the M@CuO shows a strong Fenton effect at room temperature （25 ℃）， and the Fenton reaction rate can be further enhanced by the photothermal effect， with the reaction rate at 45 ℃ being 2.3 times that at 25 ℃ under the same conditions. In vitro cell experiments reveal that M@CuO has good biocompatibility and can effectively kill tumor cells through combined PTT-CDT. Therefore， M@CuO provides an effective strategy for developing multifunctional nanomaterials with PTT-CDT synergistic therapy.