Microstructures and mechanical properties of GH4169 alloy cylinder and its weld joints in a supercritical water reactor are studied after operating 2000 h. The results show that the GH4169 alloy cylinder exhibits good corrosion resistance under conditions of high temperature， high pressure， and sucrose mixed solution； the thickness loss rate of the cylinder is 0.005-0.255 μm/h； the corrosion products primarily consist of oxides and phosphates. However， the welded joints connecting the cylinder and other components represent a vulnerable point that significantly impacts the remaining lifespan of the reactor. The calculated crack propagation rate of the GH4169 alloy cylinder is 5.25 μm/h， indicating that it would only take 762 h for the crack to penetrate through the wall of the connector. Additionally， severe fracture occurs （the circumferential length of the crack is approximately 1/4 of the circumference） at the weld joint between cylinder and stainless-steel， resulting from the synergistic effects of galvanic corrosion， crevice corrosion， and concentrated stress. Despite these challenges， the strength loss of the cylinder is relatively small， which means that the cylinder maintains satisfactory mechanical properties.

With the widespread application of carbon fiber reinforced polymer （CFRP） in the aerospace field， studying the friction performance at the interface of CFRP and aluminum alloy connections has become increasingly important. This study experimentally investigates the influence of surface microtexture parameters on the friction performance at the aluminum alloy-CFRP interface. The results indicate that both contact pressure and microgroove geometric parameters significantly affect the interface friction performance. As the contact pressure increases from 7.5 MPa to 30 MPa， the sliding friction coefficient significantly decreases， primarily due to the formation and enhancement of a self-lubricating film. Under high contact pressure， the microstructures on the aluminum alloy surface embed into the CFRP plate， creating a plowing effect. The micro-cutting action generates epoxy resin debris that fills the microstructure grooves， forming a stable lubricating film. The groove depth has the most significant impact on friction performance， with a groove depth of 31.8 μm significantly reducing the sliding friction coefficient to 0.197. The synergistic effect of contact pressure and microtexture geometric parameters markedly improves the interface friction performance and connection strength. This study provides theoretical basis and practical guidance for optimizing composite material connection technology.

The desirable combination of ultra-high strength and good toughness enables the secondary hardening ultra-high strength steel widely used in aerospace and energy equipment. The influence mechanism of quenching temperatures on the microstructure and mechanical properties of Co-conserving 2.2 GPa ultra-high strength steel is investigated by using scanning electron microscope（SEM），transmission electron microscope（TEM），tensile and impact testing machine. The results show that when the quenching temperature is 950 ℃， there are many undissolved M₆C carbides and unrefined grains in the matrix， resulting in lower strength （tensile strength：2072 MPa， yield strength：1873 MPa）. As the quenching temperature increases， recrystallization promotes the refinement of the matrix grains， and the number of M₆C carbides gradually decreases； such partial dissolution favors the precipitation of hardening phases， resulting in a recovery of strength； when the quenching temperature is 1030 ℃， the experimental steel has excellent combination of strength-plasticity-toughness： the tensile strength is 2251 MPa， the yield strength is 1901 MPa， the elongation is 9%，and the V-notch impact absorbed energy is 9 J. By further increasing the quenching temperature， the rapid growth of austenite grains leads to severe plasticity attenuation， with elongation of only 4.5% at 1120 ℃. Between 1030-1090 ℃， there is a competitive relationship between the dissolution of M₆C carbides and grain growth. Although higher temperature quenching promotes dissolution， the severe coarsening of grains offsets the former’s beneficial effect on toughness to enable a stable performance of strength and toughness.

Interlayer crack is a significant obstacle to the wide-scale implementation of light-cured additive manufacturing in industrial applications. The formation mechanism of crack defects during the forming and debinding stages of the process is investigated and their effects on the properties of light-cured ZrO₂ ceramics are analyzed. Furthermore， the study compares and analyzes the influence of exposure time and debinding rate on the distribution of cracks in ZrO₂ ceramics. The research analyzes and compares the influence of exposure time and debinding rate on the distribution of cracks in ZrO₂ ceramics. The results indicate that it is easier to obtain defect-free ceramic green bodies when the slice thickness matches the exposure layer thickness. Moreover， the study observes that the green body exhibits the least number of surface cracks when the debinding rate is set at 0.1 ℃/min. Consequently， the research achieves the successful production of ceramic parts with a density of 99% and a flexural strength of 450 MPa.These findings establish a solid scientific foundation and provide valuable technical guidance for the manufacturing and application of defect-free ZrO₂ ceramics using light-cured additive manufacturing.

Key components of high-end equipment are often exposed to harsh wear， corrosion or high-temperature environments， thus requiring higher wear resistance， corrosion resistance and high-temperature resistance. As one of the most promising surface engineering technologies at present， thermal spraying technology can be widely applied to many key components of high-end equipment to achieve the purpose of improving their surface performance. Nano thermal spraying technology is an important means to effectively combine nanomaterials and thermal spraying technology to achieve material surface modification. It is also an effective solution to extend the service life of aircraft， ships， and other high-end defense equipment in extreme environments. Nanostructured powder re-granulation technologies enable precise control over the phase composition and microstructure of thermal spray feedstocks at the nano-micro scale. This facilitates the fabrication of nanostructured coatings with tailored properties to meet diverse surface performance requirements for critical components in advanced equipment. This paper briefly summarizes the development status of nanostructured coatings with different functional orientations prepared by thermal spraying at home and abroad in the recent decade， mainly including nanostructured wear-resistant and corrosion-resistant ceramic coatings， nanostructured thermal barrier coatings， nanomodified MCrAlX alloy coatings， nanomodified WC-Co based cermet coatings and nanostructured environmental barrier coatings， etc. The results show that nanostructured and nanomodified thermal spray coatings have a very good potential to be applied on key components of high-end equipments， which can be used to meet the various surface properties required by key component of high-end equipment. key components of high-end equipment have very broad application prospects. To realize the wide application of nanostructured coatings， further research work needs to be carried out in the future in the areas of practical engineering application research， marine environmental service， marine biofouling， advanced powder preparation technology research， and high-performance powder industrialization.

The MnO₂ and VB₂ co-doped NiCr₂O₄ coatings（MV） with different ratios of moles are prepared by atmospheric plasma spraying（APS）， and the phase composition， microstructure， infrared emissivity and thermal shock resistance of the coatings are investigated. The results show that the co-doping of NiCr₂O₄ with MnO₂ and VB₂ can more effectively improve the infrared emissivity of the coatings than the doping of MnO₂ or VB₂， thus the coating with MnO₂ and VB₂ doping ratio of 1∶1 （MV11） has the highest emissivity. In the 0.75-2.5 μm wavelength ranges， the room temperature band emissivity of the MV11 coating is 0.928， and in the 2.5-25 μm， the infrared emissivity of the coating increases from 0.884 at room temperature to 0.918 at 1000 ℃. It is mainly attributed to the transition metal ions and B ions enter the spinel lattice， increasing the concentration of oxygen vacancy in the lattice， introducing partial energy levels into the bandgap， and causing lattice distortions， enhancing free carrier transition absorption and infrared lattice vibration absorption. In addition， after 30 thermal cycles of water cooling at 25-750 ℃， microcracks appear in the coating， but the phase structure did not change significantly， and the emissivity decreases slightly， indicating that the coating has good thermal shock resistance.

Silicon carbide and 2024 aluminum alloy powders with average particle sizes of 14 μm and 15 μm are selected as the reinforcement phase and matrix alloy， respectively. SiC_p/2024Al composites with volume fractions of 35%， 45%， and 55% are fabricated by hot isostatic pressing. The influence of aging treatment on the mechanical properties of the composites is investigated. The results show that aging treatment significantly enhances the hardness of the composites. Increasing the aging temperature and the volume fraction of SiC both shorten the peak aging time of the composites. When the aging temperature is increased from 160 ℃ to 190 ℃， the peak aging time of the composite with a 35% volume fraction is reduced from 9.5 h to 2 h. At 190 ℃， the peak aging time of all three volume fraction composites is shortened to 2 h. The precipitation strengthening of the matrix alloy during the heat treatment process results in higher flexural strength in the aged composites compared to the as-sintered composites with the same volume fraction. The higher the matrix alloy content， the more significant the strengthening effect. Among them， the peak-aged composite with a 35% volume fraction exhibits the highest flexural strength， reaching 901 MPa at 170 ℃. With the increase of volume fraction， the matrix alloy content decreases， reducing the ability of the material to alleviate local stress concentration through plastic deformation. Moreover， defects in the composites gradually increase. Therefore， both the as-sintered and heat-treated composites with a 55% volume fraction exhibit lower flexural strength. However， the micro-yield strength of the aged composites is higher than that of the as-sintered composites. The aged composite with a 45% volume fraction generally has the highest micro-yield strength， fluctuating in the range of 361-380 MPa， while the aged composite with a 55% volume fraction has the lowest micro-yield strength. The micro-yield strength of the composite with a 35% volume fraction initially increases and then decreases with increasing temperature， reaching its highest value （368 MPa） at 180 ℃， slightly higher than that of the composite with a 45% volume fraction under the same conditions.

Carbon fiber reinforced thermoplastic composites（CFRTP） have superior comprehensive mechanical property，as well as rapid prototyping，weldability and recyclability.The application of CFRTP are gradually increasing in aerospace，vehicle manufacturing and other fields.Ultrasonic welding is recognized as one of the most suitable methods for CFRTP.With the increase of the application of CFRTP in aerospace main load-bearing structures，the discrete solder joints in the form of traditional ultrasonic spot welding are difficult to meet the requirement of the strength of them.Accordingly，foreign scholars have proposed ultrasonic continuous welding technology to realize the seam welding connection of CFRTP structures，which has not been reported in domestic literature.In this paper，the research results of CFRTP ultrasonic continuous welding are reviewed from four aspects：CFRTP ultrasonic continuous welding equipment，joint design，process characteristics and quality inspection.The scientific problems and technical bottlenecks to be solved in CFRTP ultrasonic continuous welding are discussed，so as to provide a reference for the development of CFRTP ultrasonic continuous welding technology of our country.

Lead sulfide quantum dots （PbS QDs） have excellent optoelectronic properties and strong near-infrared light absorption，making them ideal materials for the preparation of near-infrared photodetectors. However，there are still challenges in the process and insufficient performance of the PbS QDs-based optoelectronic detection. In this study，PbS QDs are synthesized by the hot injection method，and the PbS quantum junction infrared detector is prepared by the layer-by-layer method and the solid-state ligand exchange method. The photoelectric performance of the PbS quantum junction infrared detector is improved by the thermal annealing process，and the effect of annealing temperature on the photoelectric performance of the PbS quantum junction is described. The results show that annealing effectively reduces the dark current of the PbS quantum junction infrared detector while increasing the photocurrent，and obtains a stable photoresponse current output. After annealing，the response time of the PbS quantum junction infrared detector is shortened，resulting in a time of 1.9 ms and a delay time of 3.2 ms. The sensitivity of the detector is improved，and the responsivity and detectivity are increased by 1.2 times and 1.3 times，respectively，resulting in a responsivity of 0.78 A·W^-1 and a detectivity of \mathrm{7.8}\times {\mathrm{10}}^{\mathrm{11}}\mathrm{c}\mathrm{m}\bullet \mathrm{H}{\mathrm{z}}^{\mathrm{1}/\mathrm{2}}\bullet {\mathrm{W}}^{-\mathrm{1}}. Annealing effectively improves the crystallinity and the carrier mobility of PbS QDs thin films，while reducing the defect states at the film and interface，resulting in a comprehensive improvement in the optoelectronic performance of PbS quantum junction infrared detectors.

This study utilizes mushroom stalks as a biological template and melamine as a precursor for carbon nitride to synthesize g-C₃N₄/C，via thermal polymerization method. Copper sulfate pentahydrate （CuSO₄·5H₂O），ammonium molybdate tetrahydrate （（NH₄）₆Mo₇O₂₄·4H₂O），and thiourea （CH₄N₂S） are selected as the sources for Cu，Mo，and S，respectively. A two-step hydrothermal process is employed to prepare CuS/MoS₂ composites with different mass ratios. Then CuS/MoS₂ is anchored on the surface of g-C₃N₄/C to obtain CuS/MoS₂-g-C₃N₄/C composite electrode materials. The composite electrode materials are characterized by their phase structure，microstructure，pore structure，and capacitance performance. The results indicate that the CuS/MoS₂-g-C₃N₄/C composite electrode materials exhibit high purity，good crystallinity，good phase contact interface， and abundant porous structure. In electrochemical performance testing，the CuS/MoS₂ composite material with a mass ratio of MoS₂ to CuS at 1∶2 demonstrates optimal electrochemical performance，achieving a specific capacitance of 230 F·g^-1 at a current density of 1 A·g^-1. When the mass ratio of CuS/MoS₂ to g-C₃N₄/C is 1∶1，the CuS/MoS₂-g-C₃N₄/C composite material exhibits the best electrochemical performance，with a specific capacitance of 434.7 F·g^-1. Moreover，after 1000 cycles，the capacitance retention rate is 89.2%，showing good stability.