In the pursuit of achieving a superior thrust-to-weight ratio and service reliability for advanced aero engines， increasingly stringent requirements are continually imposed on the material and process selection for turbine blades. Turbine blades featuring nickel-based single crystal superalloys with thermal barrier coatings have emerged as a hallmark of advanced aero engines. The research and development of nickel-based single crystal superalloys and thermal barrier coating materials， coupled with the evaluation of nickel-based single crystal superalloy/thermal barrier coating systems， are pivotal in ensuring the safe and reliable performances of turbine blades. This topic is among the hottest in the field. This paper provides a comprehensive introduction to the research and application of nickel-based single crystal superalloys and thermal barrier coating materials for turbine blades. It summarizes the evaluation methods and failure mechanisms of single crystal superalloy/thermal barrier coating systems. Finally， the research focuses on nickel-based single crystal superalloy/thermal barrier coating systems are highlighted， aiming to serve as a valuable reference for fully harnessing the potential of these systems.

The combination of multiple temperature gradients in interconnect solders is key to achieving high-density chip integration. Low-temperature solder alloys are the premise for implementing low-temperature processes and the guarantee for high reliability of electronic products.This article reviews the research progress in Sn-58Bi low-temperature solders， In-based （In-Sn， In-Pb， In-Ag， In-Bi） low-temperature solders， and other low-temperature solders （multicomponent alloys， high-entropy alloys， Ga-based alloys）. It is pointed out that Sn-Bi solders containing Bi cannot avoid Bi segregation and brittle fracture. The optimal choice is to use mixed solders in the soldering process， utilizing other solders or adding particles to react with Bi to form Bi-containing compounds that consume Bi， without losing the weldability of Sn-Bi solders and matching existing reflow processes. In-based binary or multicomponent low-temperature solders and SnBiInX high-entropy alloys will inevitably form brittle Bi phases and low-melting-point Bi-In or Sn-In compounds after soldering. It is advisable to abandon the use of Bi and control the content of Sn. For example， mixing low-melting-point Ga or In with high-melting-point Cu to form non-metallurgical mixed or composite solders， low-temperature transient liquid phase bonding realizes low-temperature interconnection near the melting temperature of low-melting-point components. The consumption of low-melting-point phases and the formation of high-melting-point compounds are the prerequisites for ensuring high strength of the solder joint and high-temperature service.

Certain materials，when exposed to light irradiation， exhibit the ability to undergo electron transitions， resulting in the generation of electron holes. These electron holes， upon separation， produce active substances， thereby realizing the photocatalytic effect， which holds significant promise for addressing the energy crisis and mitigating environmental pollution. To enhance the photocatalytic effect， external fields， such as electric and magnetic fields， are employed for modulation. Among them， magnetic field modulation stands out due to its non-contact nature and simplicity， effectively boosting photocatalytic activity by facilitating the separation of photogenerated carriers. This approach has garnered considerable attention in the field of photocatalysis. In this paper，we comprehensively review the research advancements in magnetically induced carrier separation for enhanced photocatalysis. Subsequently， we delve into the physical mechanisms underlying magnetic field-enhanced photocatalysis， examining how magnetic fields influence solution absorbance， promoting the separation of photogenerated carriers， and regulating the spin-polarization process. Finally， we consolidate and categorize the reaction conditions for magnetic field-optimized photocatalysis， as well as the modulation mechanism of the magneto-thermal effect on photocatalysis， with the aim of providing scientific insights for future enhancements in photocatalytic efficiency.

This paper focuses on the theoretical innovation from Fourier heat conduction to non-Fourier heat conduction and its key application in the field of extreme heat transfer. Firstly， this paper describes the classical theory of Fourier heat conduction law and its applicability in conventional heat transfer scenarios， and reveals its limitations in analyzing energy transfer under ultra-fast， ultra-short-range， and ultra-low temperature conditions. Then the non-Fourier heat conduction theory is deeply discussed， and the Cattaneo-Vernotte equation and the dual-phase lag （DPL） model are introduced. By introducing the lagging effects of heat flux relaxation time and temperature gradient relaxation time， the theoretical boundary of the traditional Fourier heat conduction model is broken. Fourier boundary conditions should be adopted in Fourier heat transfer governing equations， while non-Fourier boundary conditions should be adopted in non-Fourier heat transfer governing equations. In this paper， the mathematical expressions of three kinds of non-Fourier boundary conditions are given for the first time in supernormal hot working processes. By comparing the numerical simulation results of Fourier heat conduction model and non-Fourier heat conduction model with the experimental test results， it is found that non-Fourier model has obvious advantages in predicting the transient response of temperature field， the size of heat affected zone （HAZ） and the optimization of laser process parameters， which verifies the accurate prediction ability of non-Fourier model for extreme heat transfer conditions and provides important theoretical support for revealing the heat transfer mechanism of high-end equipment and extreme working conditions.

Rubber materials have excellent vibration reduction， sound insulation， and buffering functions. Shock absorbers designed and manufactured with rubber and metal as raw materials are widely used in fields such as aviation， aerospace， weapons， and ships. However， it is costly to adopt the method of test-guided design. Finite element simulation can reduce the cost significantly， so that the design and optimization of rubber shock absorbers can be better conducted. Rubber materials are highly nonlinear， so it is a key and difficult problem in finite element analysis to establish a proper constitutive model to describe the mechanical properties. The classical constitutive models of hyperelasticity and viscoelasticity of rubber materials are summarized， and their applicability and rationality are analyzed and reviewed in combination with the changes caused by the development of rubber materials. The application of different constitutive models in finite element analysis and the accuracy of calculation are demonstrated by analyzing the dynamic and static stiffness， resonance and shock of rubber shock absorbers. Finally， it is pointed out that the innovation of rubber material constitutive model and the development direction of finite element modeling， such as the realization of the simulation application of new constitutive model through the secondary development of finite element software， the innovation of constitutive model and finite element theory considering environmental factors and engineering practice， and the exploration of the internal relationship between material formula and constitutive model.

To investigate the formation of multilayer structures in high-temperature components of gas turbines， extensive long-term thermal exposure experiments are conducted on nickel-based casting superalloy K444 at 1000 ℃ in air. The morphology， structure， and composition of the multilayer structure on both the surface and cross-section of the alloy are meticulously characterized and analyzed using scanning electron microscopy （SEM）， energy dispersive spectroscopy （EDS）， and X-ray diffraction （XRD）. The results show that the multilayer structure of the K444 alloy comprises an outermost continuous oxide layer predominantly of Cr₂O₃， interspersed with minor amounts of TiO₂ and NiO， a subsurface discrete oxide layer of Al₂O₃， and an innermost layer enriched with TiN. The thickening curve of the alloy oxide film during thermal exposure adheres to the parabolic law， and the thickening rate of the oxide film gradually decreases as the thermal exposure progresses. The outermost dense oxide layer of Cr₂O₃ formed due to its lower thermal expansion coefficient， serving as a significant barrier to oxygen penetration. The scarcity of Al in the oxide layer， attributed to its lower diffusion coefficient， leads to its aggregation in the sub-outer layer， forming a discrete inner oxide layer. Furthermore， a competitive reaction between oxygen and nitrogen occurres in the innermost layer of the alloy. As the partial pressure of oxygen decreases and the partial pressure of nitrogen relatively increases， the Ti element undergoes a nitriding reaction to form TiN， which subsequently oxidizes to TiO₂ as oxidation progressed. The research findings elucidate the formation mechanism of the multilayered film structure of K444 and the process of long-term thermal exposure at 1000 ℃， providing a theoretical foundation for its further application at high temperatures.

The phase transformation behaviors of the joint are studied using scanning electron microscope and electron backscattered diffraction， and the comprehensive mechanical properties of joint are enhanced by annealing heat treatment. The results show that complete dynamic recrystallization and β→α΄ phase transformation occur in the weld zone（WZ） of the as welded joint. Under the thermo-mechanical coupling effect， the rod-shaped α phase exhibits significant elongation deformation along the friction direction in the thermo-mechanically affected zone， accompanied by obvious decomposition and breaking spheroidization. In the heat-affected zone， the rod-shaped α phase within the grains is similar as the base metal， whereas the secondary α phase in the original β matrix is completely dissolved under high temperature during welding. After welding， fine secondary lamellar α phase precipitates at the boundary between α and β phase. The tensile property tests reveal that WZ is the weak area of the joint. The tensile strength， elongation and section shrinkage of the joints are 1048.6 MPa， 6.1% and 5.7%， respectively. After annealing heat treatment of 570 ℃， large number of fine acicular secondary α phases whose are interweaved are precipitated in WZ， resulting in the damage tolerance microstructural characteristics （interweaved secon-dary α） of TC21 titanium alloy are restored in WZ. Therefore， the tensile strength and elongation are obviously increased to 1131.4 MPa and 9.4%， respectively.

The mechanical properties of wire-arc additive manufactured （WAAM） 2319 aluminum alloy are significantly influenced by the distribution of precipitates. However， the non-equilibrium solidification microstructure under cold metal transfer （CMT） and its evolution mechanism during heat treatment remain unclear. 2319 aluminum alloy specimens are fabricated using CMT-ed WAAM， with some subjected to T6 heat treatment. The distribution of precipitates in the upper， middle， and lower regions of the specimens is systematically investigated before and after heat treatment to elucidate their correlation with mechanical properties and the underlying strengthening mechanisms. The results indicate that the as-deposited specimens exhibit an average tensile strength of 175 MPa. The lower region near the substrate， which contains the highest volume fraction （20.8%） of coarse θ phases， demonstrates the greatest tensile strength （192 MPa）. After T6 heat treatment， the volume fraction of θ phases in the upper， middle， and lower positions of the samples decreases by about 80%. Meanwhile， a large number of small needle-like θ′ phases are formed in the matrix， and these dispersed θ′ phases play a major strengthening role， making the average tensile strength of the sample reach 365 MPa. Both as-deposited and heat-treated samples exhibit three strengthening mechanisms： precipitation strengthening， solid solution strengthening， and grain refinement strengthening. The substantial strength improvement in heat-treated samples primarily originates from precipitation strengthening induced by the θ′ phases.

The corrosion behavior and electrical conductivity of 1050A aluminium alloy conduct materials in simulated marine and industrial atmosphere are studied in this paper. Cyclic wet-dry immersion test and mass loss measurement are carried out to investigate the corrosion behavior of 1050A aluminium conduct material. The corrosion morphology of aluminium is observed and analyzed by using ultra-depth field microscopy and optical profilometer. The electrical properties are tested by micro-ohmmeter， conductivity testing meter， and digital bridge， respectively. In addition， the development and variation of corrosion parameters such as corrosion mass loss， corrosion rate， surface roughness， and pit depth and diameter are explored. Under the simulated marine atmospheric environment， it is found that the corrosion mass loss of 1050A aluminium is small and the pitting characteristics are obvious， the maximum corrosion pit depth and diameter can reach 36 μm and 80 μm respectively. However， in the simulated industrial atmospheric environment， the corrosion pits of 1050A aluminium are dispersed and the development of pitting parameters is not obvious， while the corrosion mass loss has the development trend of uniform corrosion. Moreover， the on-resistance and 20 ℃ resistance values of 1050A aluminium conductor parts increase obviously， and the conductivity decreases significantly with the development of corrosion in two typical atmospheric environments. In summary， the corrosion behavior and development law of aluminium conductors in simulated marine and industrial atmosphere are significantly different. The pitting corrosion characteristics of aluminium conductors are obvious， and the conductivity is closely related to the depth of corrosion pits in simulated marine atmosphere. However， the corrosion mass loss of aluminium conductor develops monotonously， and the conductivity has a high correlation with the corrosion mass loss in simulated industrial atmosphere. Therefore， the development trend of electrical conductivity of aluminium conduct materials in marine and industrial atmosphere can be predicted by pit depth and corrosion mass loss parameters respectively.

The cohesive force unit is added to the three-dimensional model of SiC particle-reinforced magnesium matrix composites （SiC_p/AZ91D） using the finite element analysis program Abaqus， and the mechanism of crack sprouting extension of SiC_p/AZ91D with different particle equivalent sizes and volume fractions under uniaxial compression is investigated. The invention of the cohesive force unit offers a new approach to addressing the issue of crack extension by avoiding the shortcomings of specimens with prefabricated cracks and the singularity of the crack tip. The results show that the yield strength and compressive strength of SiC_p/AZ91D are significantly higher than that of the matrix， while the plasticity is decreased. The microcracks of SiC_p/AZ91D are first initiated at the junction of particle and matrix and then propagate around the boundary or sharp angle of SiC particles along the direction of maximum shear stress， forming the main crack. The increase in particle equivalent size and volume fraction will accelerate the crack germination and propagation process of SiC_p/AZ91D.

M35 high speed steel is prepared by electron beam smelting （EBS） technology and subjected to forging and heat treated. The EBS-M35 is characterized by X-ray fluorescence spectroscopy （XRF）， X-ray diffractometer （XRD）， oxygen and nitrogen analyzer， metallographic microscopy （OM）， scanning electron microscopy （SEM）， and Rockwell hardness tester methods. The distribution characteristics of carbides in the casting， forging， and tempering states of EBS-M35 are investigated， and the effect of heat treatment process on the hardness and red-hardness of EBS-M35 is discussed. The results show that the carbide network spacing in the as-cast EBS-M35 is smaller， with the average of 22.96 μm， representing 64.68% reduction compared to that observed in conventionally prepared process. The average size of carbide decreases as the forging ratio increases. At a forging ratio K of 13， the average size of carbide in EBS-M35 is only 2.97 μm. In addition， after quenching and three cycles of tempering at 560 ℃， the peak hardness of EBS-M35 is 67.2HRC quenching at 1130 ℃， and peak red-hardness of 600 ℃ （quenching at 1160 ℃） is 64.7HRC. Compared to the traditional preparation process， EBS-M35 exhibits an increase in hardness by 0.8HRC and in red-hardness by 1.7HRC.

M2 high-speed steel is one of the key materials for the preparation of high-performance precision cutting tools. In this study， crack-free M2 steel is fabricated by laser powder bed fusion （L-PBF） method with a high substrate preheating temperature of 300 ℃， and the effects of scanning parameters on density， microstructure， hardness， and wear resistance are analyzed. Results show that the relative density of the M2 steel is more than 99.4% when the laser power and scanning speed are 260 W and 0.8 m·s^-1， respectively. In addition， the M2 steel is mainly composed of fine equiaxed ferrite and a large number of strip-like （about 10 μm in length） martensite as well as lower bainite， and no conventional network coarse eutectic carbide can be found. The main reason for the formation of lower bainite is that the high substrate preheating temperature enables the specimen to maintain its temperature higher than the martensite transition point （<200 ℃） for a period of time during the rapid cooling process， and the increase of heat input will lead to an increment in content of lower bainite. The hardness of the fully dense M2 steel （813.2HV_0.3） is slightly lower than that of wrought bulk （quenched and tempered）， but the compressive strength （3.51 GPa） and compressive ductility （32%） are comparable to those of bulk counterpart. Moreover， the fully dense M2 steel shows an excellent wear performance and its wear rate （3.98×10⁵ mm³·N^-1·m^-1） is 36.1% lower than that of the bulk counterpart.

The central composite design （CCD） of response surface methodology is used to optimize the cold metal transfer and pulse hybrid （CMT+P） wire arc additive forming process of duplex stainless steel. A mathematical regression model is constructed between the wire feeding speed， movement speed， pulse number and the forming quality （deposited width， forming error， and austenite content） of the deposited parts. The influence of different process parameters on forming quality is studied through variance analysis， perturbation plots and response surfaces. The results show that the deposited width and austenite content decrease with increasing moving speed， but increase with increasing wire feeding speed and pulse number； By increasing the wire feeding speed or moving speed， the forming error first decreases and then increases， and the impact of pulse number is not significant. The optimized process parameters are wire feeding speed of 3.9 m/min， moving speed of 5.5 mm/s， and pulse number of 12.

In the roll forming， the sheet metal will experience multiple bending processes. The nonlinear hardening behavior and cyclic plastic behavior of high strength steel during multiple bending deformation， such as Bauschinger effect and cyclic hardening/softening， will affect the springback results. For QP980 high-strength steel， based on the Mises yield criterion and isotropic hardening （IH） model， linear follow-up hardening model （Prager model）， Chaboche kinematic hardening （Chaboche-KH） model， Chaboche mixed hardening （Chaboche-MH） model， the UMAT subroutine is used in ABAQUS to realize the four models and to simulate the roll bending. By comparing the simulation and test results， the possible cyclic plasticity behavior of high strength steel in the roll bending and its influence on springback are analyzed. The results show that for roll forming， there is no cyclic plastic behavior in single pass forming. Chaboche model considering nonlinear hardening can obtain more accurate prediction results. Therefore， QP980 high strength steel has nonlinear hardening， Bauschinger effect and cyclic hardening behavior in the roll forming. Chaboche-MH model， which considers the above three material behaviors at the same time， has the highest prediction accuracy for springback in the roll bending forming. The prediction error of single pass forming is not more than 1°， and the prediction error of multi pass forming is within 2°.

Hexagonal boron nitride （h-BN） has excellent thermal conductivity， electrical insulation properties， and chemical stability due to its standard hexagonal crystal structure and wide electronic band gap， which has a wide application prospect in the field of thermal insulation. However， pure h-BN has a certain chemical inertness. Therefore， the ultrasound-assisted liquid-phase exfoliation method has been used to functionalize the surface of h-BN with branched polyethyleneimine （PEI） to increase its surface activity. The modified boron nitride nanosheets （PEI-BNNS） are blended with cellulose nanofiber （CNF） to prepare composite flexible thermally conductive films using the method of vacuum filtration， with PEI-BNNS as the thermal conductive filler and CNF as the matrix. The results show that the hydrogen bond increases the interaction force between the thermal conductive filler and the matrix， enabling PEI-BNNS to be better dispersed in the CNF matrix. CNF acts as a “bridge” connecting PEI-BNNS to form a relatively complete thermal conductive network， significantly improving the thermal conductivity and mechanical properties of the flexible thermally conductive films. The thermal conductivity of the 30% （mass fraction） PEI-BNNS/CNF thermally conductive film reaches 42.59 W/（m·K）， and the elastic modulus reaches 41.89 MPa.

The stress field of V-notch composite plates is simplified by introducing the equivalent strength factor as ₁. A semi-analytical formula for the stress field of single-edge V-notched composite plates is derived theoretically， and a simplified formula for as ₁ is obtained through finite element analysis fitting. The simplified evaluation formula for the notched stress field of composite structures is validated using numerical and experimental methods. The results show that the simplified formula exhibits high consistency with both finite element results and experimental data. Fatigue tests are conducted on notched composite plates to obtain the S-N curves of V-notched specimens. By combining the notched stress field and the predictive formula for the notch stress intensity factor K， the K-N curves of the notched specimens are fitted. The results indicate that the K-N curves based on the notch stress intensity factor have a narrower scatter band， enabling higher-precision evaluation of the fatigue strength of notched composite structures.

The dynamic mechanical properties of satin weave carbon fiber fabric resin based composite material Q/2AJ1011 in the warp and weft directions are studied using a split Hopkinson pressure bar （SHPB） experimental device at six temperatures ranging from -55 ℃ to 75 ℃ and three strain rates. The damage characteristics are studied using scanning electron microscopy. The results show that the material exhibits significant temperature sensitivity under dynamic compression. The compressive strength of the fiber at three strain rates in the warp direction and at high strain rates of 1250 s^-1 in the weft direction is basically affected by temperature changes， with 25 ℃ as the peak point of compressive strength，it decreases with the increase of temperature， and the decrease ratio reaches 18% with the increase of temperature to 75 ℃.As the temperature decreases to -25 ℃， the compressive strength of the material shows a decreasing trend， with a decrease ratio of 23% at -25 ℃. As the temperature further decreases to -55 ℃， the compressive strength significantly increases； However， the fiber weft direction exhibits a hysteresis phenomenon in the temperature effect at lower strain rates of 850 s^-1 and 1100 s^-1， with 50 ℃ being the maximum strength. At the same time， it is found that intrinsic brittle materials exhibit certain elastic-plastic deformation at high temperatures. The material strength is not sensitive to changes in strain rate， and the performance changes are within 10%. The damage characteristics are greatly influenced by temperature and strain rate， with an increase in strain rate leading to a significant increase in shear. The influence of temperature results in a clear brittle fracture feature of concentrated through layered cracks at low temperatures， while an increase in debonding at high temperatures indicates a weaker interfacial bonding.

In order to clarify the influence of the storage time of sizing agent raw materials on the surface properties， processing properties and composite properties of domestic carbon fibers， SEM， AFM and XPS are used to characterize the surface morphology and elements of domestic carbon fibers with sizing agent storage time of 3 months， 12 months and 18 months respectively， and thermogravimetric analysis， dynamic contact angle method and fuss mass method are used to test the processing properties of the fibers， and the mechanical properties of the fibers and composites are characterized. The results show that as the storage time of sizing agent raw materials increases to 18 months， the fiber surface roughness increases， the fiber surface O/C ratio and the active C atom ratio decreases significantly， and the sizing agent thermal stability deteriorates significantly， and the wettability of fiber and LHY-1 resin decreases， and the wear resistance of fiber significantly decreases， and the dispersion of fiber linear density increases significantly， and the 90°tensile strength/modulus and interlaminar shear strength of the composite decreases significantly， and the dispersion of 90° tensile strength increases.

To solve the problem of insufficient fatigue resistance of full carbon fiber reinforced polymer composites during use， and to make a bicycle rim with the advantages of strong compression resistance， strong fatigue resistance and moderate cost， the bicycle rim with carbon/glass inter-ply hybrid fiber reinforced epoxy composites is designed and numerically analyzed. Firstly， the mechanical properties of fiber and epoxy are used in unit cell theory to calculate the orthotopically mechanical properties of continuous fiber reinforced composites， as the input parameters of ABAQUS software. Then， the effects of the variation of the hybrid ratio and stacking sequence on the mechanical properties of bicycle rim in-service is calculated by the hybrid ratio and tacking sequence of the side wall and the rim bead of the bicycle rim， respectively. Multiple sets of hybrid ratio of carbon fiber （CF） and glass fiber （GF） and layup schemes are designed， calculated and analyzed to obtain the optimized hybrid ratio and stacking sequence. Results show that the best hybrid ratio CF/GF of the side wall is 3∶2， and the best hybrid ratio CF/GF of the rim bead is 10∶16. The results of 50000 times accelerated fatigue test demonstrate that selecting the optimal hybrid ratio layup scheme to make composite bicycle rim can significantly improve its fatigue resistance because hybrid composite can inhibit interlaminar crack.

NH₂-UIO-66 loaded MBT functionalized g-C₃N₄ nanosheets （UMC） are synthesized by a one-step solvothermal method. Added to water-based epoxy acrylate （WEP） emulsions，this new composite（UMC/WEP） is used as an anticorrosive agent to protect metal substrates. The release behavior of UMC corrosion inhibitor at different pH values has measured by UV spectroscopy，which shows that UMC has loaded about 14.2% （mass fraction，the same below） of MBT. UMC can be well dispersed in the waterborne epoxy-acrylate emulsion，and the SEM image of the coating cross-section shows that UMC has good compatibility with WEP. The anti-corrosion performance of composite coating and artificial scratch coating on Q235 carbon steel in 3.5% NaCl solution are evaluated by EIS，and the corrosion products are characterized by SEM-EDS. The results show that even after prolonged immersion （60 days） in the NaCl solution，the |Z _{0.01 Hz}| of UMC/WEP is still as high as 1.19×10¹⁰ Ω·cm²，which is 4 orders of magnitude higher than that of the WEP coating. SEM-EDS data exhibits that the metal surface protected by UMC/WEP coating has fewer corrosion products compared with the other three coatings，and the iron content in the corrosion products is the highest，up to 93.84%，while the oxygen and chlorine contents are as low as 6.00% and 0.16% respectively. After soaking in 3.5% NaCl solution for 48 h，the value of impedance and |Z _{0.01 Hz} | of UMC/WEP with artificial scratch is enhanced. In the early stage of immersion of UMC/WEP coating，the labyrinth barrier effect of g-C₃N₄ nanosheets plays a passive anti-corrosion function. In the later stage，when corrosion occurs，NH₂-UIO-66 releases MBT and Zr⁴⁺ in time to play an active anti-corrosion function. In addition，Zr⁴⁺ in NH₂-UIO-66 will compete with Fe³⁺ and Fe²⁺ for OH^-，forming a protective film，which also helps to slow down the corrosion of metal.

Polymer film capacitors play an important role in national economy and defense military field such as new energy vehicles， photovoltaic/wind power generation， naval vehicle ejection systems and smart grids because of their fast charging-discharging characteristics. The existing energy storage density of the most commonly used polymer dielectric-biaxially oriented polypropylene （BOPP） film is low， which is not conducive to the light weighting and integration of energy storage devices. All-organic composite dielectric films are prepared with high dielectric constant polyvinylidene fluoride （PVDF） as the matrix and linear homopolymer polystyrene （PS） as the filler. To solve the problem of PS phasing in the PVDF matrix， PVDF/PS/PVDF composites with sandwich structure are prepared by layer-by-layer electrospinning-hot pressing technique. The results show that PS can significantly limit the ferroelectric relaxation loss of the composites， and the sandwich structure can optimize the electric field distribution and suppress carrier migration in combination with the phase field simulation analysis， and the energy storage density（U _e） and efficiency （η） of the composite films with 30% （mass fraction） PS are 11.7 J/cm³ and 75% at a field strength of 446 MV/m， respectively， the significantly improved energy storage performance provides the basis for the development and application of all-organic composite dielectric films.

To solve the problem that the cutting temperature rises sharply due to the high friction coefficient of AlCrSiN coated tools during dry cutting， which seriously shortens the service life of the tool， the tribological properties of the coating are improved by doping the sixth group Mo element in the AlCrSiN coating. AlCrSiN/Mo coating is prepared by high-power pulsed magnetron sputtering and pulsed DC magnetron sputtering composite coating technology under different deposition pressures， the coating composition and structure are adjusted， and the composition， structure， mechanical properties， and tribological properties of the coating are characterized by scanning electron microscopy， electron probe analyzer， X-ray diffractometer， nanoindentation， scratch tester， and friction and wear testing machine. The results show that with the increase of deposition pressure， the optimal growth orientation of the coating changes from （111） crystal plane to （200） crystal plane， and the microstructure becomes denser. The critical load of the coating gradually increases from 65.6 N to 82.0 N， but the deposition rate decreases linearly. When the deposition pressure is 1.6 Pa， the hardness and elastic modulus of the coating reach the highest values， which are 20.6 GPa and 394.3 GPa， respectively. The characteristic values H/E and H ³/E*² also reach the maximum， which are 0.052 GPa and 0.046 GPa， respectively， when the tribological properties of the coating are the best， and the friction coefficient and wear rate are 0.59 and 1.52×10^-3 μm³·N^-1·μm^-1，respectively.