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Journal of Advanced Ceramics 2024年第1期13卷 73-85页

作者： Jinsong Yang Fang Ye Laifei Cheng kai Zhao Yucong Wei Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China

To enhance the resistance of SiC_(f)/SiC to hydrothermal corrosion in the pressurized water reactor(PWR)environment,structurally tunable Ti_(3)SiC(2)-based corrosion mitigation coatings for SiC_(f)/SiC were prepared using molten salt *** influence of various process parameters,such as Si/Ti molar ratio in raw materials,annealing time,and annealing temperature,on the phase composition and the structure of the coatings was *** the process control,the fabricated coatings can be either Ti_(3)SiC(2) monolithic structure or TiC/Ti_(3)SiC(2) and TiC/Ti_(3)SiC(2)/Ti_(5)Si_(3)C_(x) multilayered *** coatings demonstrate strong bonding to the substrate due to in-situ reaction,exhibiting tensile and shear strength of at least 26.9 and 30.8 MPa,*** TiC as a transition layer further enhances the tensile and shear strength to 41.3 and 51.4 MPa,*** Ti_(3)SiC(2) coatings enhance the thermal conductivity of SiC_(f)/SiC by 10%–12%.Notably,Ti_(3)SiC(2) coatings effectively protect SiC_(f)/SiC from hydrothermal corrosion,demonstrating an 83%strength retention rate compared to 71%in the control group after ***,the Ti5Si3Cx layer exhibits unsatisfactory corrosion *** Ti_(3)SiC(2) monolithic coating has higher thermal conductivity,TiC/Ti_(3)SiC(2) multi-layered coating has higher bonding strength,and both have desirable resistance to the hydrothermal corrosion.

关键词： Ti_(3)SiC(2) SiC_(f)/SiC nuclear materials hydrothermal corrosion coating

Editorial:special topic on heterojunction in photocatalysts

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Science China Materials 2024年第2期67卷 379-381页

作者： Jiaguo Yu Xin Li Junwei Fu kai Dai Laboratory of Solar Fuel Faculty of Materials Science and ChemistryChina University of GeosciencesWuhan 430078China Institute of Biomass Engineering Key Laboratory of Energy Plants Resource and UtilizationMinistry of Agriculture and Rural AffairsSouth China Agricultural UniversityGuangzhou 510642China Hunan Joint International Research Center for Carbon Dioxide Resource Utilization State Key Laboratory of Powder MetallurgySchool of PhysicsCentral South UniversityChangsha 410083China Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation College of Physics and Electronic InformationHuaibei Normal UniversityHuaibei 235000China

To suppress the recombination of photogenerated electron and hole in single photocatalysts,an important method is to design heterojunction by combining two *** method has widely used to enhance the photocatalytic performance of the *** the begining,most people use type-Ⅱcharge carrier transfer mechanism to explain the emhanced activity of the composite semiconductors.

关键词： composite heterojunction method

Efficient nitrite-to-ammonia electroreduction over Zr-Ni frustrated Lewis acid-base pairs

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Science China Chemistry 2024年第5期67卷 1707-1714页

作者： Ying Zhang Zhuohang Li Wenyu Du kai Chen Ke Chu School of Materials Science and Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

Electrochemical NO_(2)~--to-NH_(3) conversion(NO_(2)RR) offers a green route to NH_(3) electrosynthesis, while developing efficient NO_(2)RR catalysis systems at high current densities remains a grand challenge. Herein, we report an efficient Zr-NiO catalyst with atomically dispersed Zr-dopants incorporated in NiO lattice, delivering the exceptional NO_(2)RR performance with industriallevel current density(>0.2 A cm^(-2)). In situ spectroscopic measurements and theoretical simulations reveal the construction of ZrNi frustrated Lewis acid-base pairs(FLPs) on Zr-Ni O, which can substantially increase the number of absorbed nitrite(NO_(2)~-),promote the activation and protonation of NO_(2)~- and concurrently hamper the H coverage, boosting the activity and selectivity of Zr-NiO towards the NO_(2)RR. Remarkably, Zr-NiO exhibits the exceptional performance in a flow cell with high Faradaic efficiency for NH_(3) of 94.0% and NH_(3)yield rate of 1,394.1 μmol h^(-1)cm^(-2) at an industrial-level current density of 228.2 m A cm^(-2),placing it among the best NO_(2)RR electrocatalysts for NH_(3) production.

关键词： electrochemical nitrite-to-ammonia conversion frustrated Lewis acid-base pairs(FLPs) in situ spectroscopy theoretical computations

Voltage rise rate-related generalised probabilistic lifetime model of turn-to-turn insulation in inverter-fed motors

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High Voltage 2024年第1期9卷 46-55页

作者： Yan Yang Xueyang Bai Yuxing Lei kai Liu Guangning Wu School of Electrical Engineering Southwest Jiaotong UniversityChengduChina

The lifetime model of turn-to-turn insulation in inverter-fed motors is studied.A lifetime model has been built by considering the effect of inverter-generated high voltage rise rate(dv/dt up to 20 V/ns).This model is followed by the generalised probabilistic model,in which the lifetime is proportional to the nth power of the voltage rise ***,by investigating the effect of voltage rise rate on the partial discharge characteristics,it is found that the effect of voltage rise rate on the charge transport process in a voltage cycle is similar to that of the voltage *** enhanced partial discharge activity and induced charges are responsible for accelerated ageing and thus determine the final lifetime of turn-to-turn *** this case,the generalised probabilistic electric lifetime model is applicable to the voltage rise rate as well as the voltage amplitude.

关键词： lifetime inverter insulation

Optically levitated micro gyroscopes with an MHz rotational vaterite rotor

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Microsystems & Nanoengineering 2024年第3期10卷 219-227页

作者： kai Zeng Xiangming Xu Yulie Wu Xuezhong Wu Dingbang Xiao College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China College of Information and Communication National University of Defense TechnologyWuhan 430000China Key Laboratory of Satellite Navigation Technology National University of Defense TechnologyChangsha 410073China

The field of levitated optomechanics has experienced significant advancements in manipulating the translational and rotational dynamics of optically levitated particles and exploring their sensing *** concept of using optically levitated particles as gyroscopes to measure angular motion has long been explored but has not yet been proven either theoretically or *** this study,we present the first rotor gyroscope based on optically levitated high-speed rotating *** gyroscope is composed of a micrometer-size ellipsoidal vaterite particle that is driven to rotate at MHz frequencies in a vacuum *** an external angular velocity is input,the optical axis deviates from its initial position,resulting in changes in the frequency and amplitude of the rotational *** analyzing these changes,the angular velocity of the input can be accurately detected,making it the smallest rotor gyroscope in the *** angular rate bias instability of the gyroscope is measured to be 0.08°/s and can be further improved to as low as 10^(−9)°/h theoretically by cooling the motion and increasing the angular moment of the levitated *** work opens a new application paradigm for levitated optomechanical systems and may pave the way for the development of quantum rotor gyroscopes.

关键词： particles. rotational angular

Effects of hot deformation and in-situ ZrB2 particle on microstructure and tensile performance of AA7085 composite sheets

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Journal of Iron and Steel Research(International) 2024年第7期31卷 1778-1791页

作者： Jiang-jing Wu Xi-zhou kai Chuang Guan Yu-tao Zhao School of Material Science and Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina

To provide a new idea to reduce anisotropy for sheets in the thickness direction by microstructure modification and,mean-while,maintain or even enhance tensile performance,the in-situ ZrB2 particle/AA7085 composite sheets with thicknesses of 1,2,3,and 6 mm were *** as-cast grain size was significantly refined by the heterogeneous nucleus of the ZrB2 *** microstructure results show that severe hot deformation converts as-cast disordered microstructure into a sequential microstructure by crushing the remanent phases and matrix into a fiber *** the solid solution and aging heat treatment,the composite sheets exhibit largely recrystallized grains compared with partially recrystallized grains in the matrix sheets,and weak or even free texture exists in the *** grain size in the composite sheets decreases with the increase in thickness *** the thickness range of 1-3 mm,the composite sheets maintain a similar tensile per-formance as that in matrix sheets,while the strength and ductility in the 6-mm-thick composite sheet are improved.

关键词： Composite sheet Grain structure Texture Dislocation Strengthening

Machining dynamics and chatters in micro-milling:A critical review on the state-of-the-art and future perspectives

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Chinese Journal of Aeronautics 2024年第7期37卷 59-80页

作者： Qingshun BAI Peng WANG kai CHENG Liang ZHAO Yabo ZHANG School of Mechanical and Electrical Engineering Harbin Institute of TechnologyHarbin 150001China Department of Mechanical and Aerospace Engineering Brunel University LondonUxbridge UB83PHUK

Micro-milling technology is widely applied in micro manufacturing,particularly for the fabrication of miniature and micro ***,the chatters and machining dynamics related issues in micro-milling are often the main challenges restricting its machining quality and *** research works have rendered that the machining dynamics and chatters in micro-milling are more complex compared with the conventional macro-milling process,likely because of the size effect and rigidity of the micro-milling system including the tooling,workpiece,process variables,materials involved,and the high-speed milling machines,and further their collective dynamic ***,in this paper,the state of the art focusing on micro-milling chatters and dynamics related issues over the past years are comprehensively and critically reviewed to provide some insights for potential researchers and ***,typical applications and the problems caused by the machining dynamics and chatters in micro-milling have been put forward in this ***,the research on the underlying micro-cutting mechanics and dynamics,stability analysis,chatters detection,and chatter suppression are summarized ***,the underlying scientific and technological challenges are discussed particularly against typical precision engineering ***,the possible future directions and trends in research and development of micro-milling have been discussed.

关键词： Micro-milling Machining dynamics Micro-cutting mechanics Stability lobe diagram(SLD) Chatters suppression Digital twin

Left atrial appendage occluder detachment treated with transthoracic ultrasound combined with digital subtraction angiography guided catcher:A case report

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World Journal of Clinical Cases 2024年第6期12卷 1157-1162页

作者： kai Yu Yun-Hua Mei Department of Ultrasound Wuhan Dongxihu District People's HospitaWuhan 430400Hubei ProvinceChina Department of Infectious Diseases Wuhan Dongxihu District People's HospitalWuhan 430400Hubei ProvinceChina

BACKGROUND There are very few cases of cardiac occluder detachment,and it is rare to completely remove the occluder using interventional methods without undergoing thoracotomy surgery after *** case innovatively used ultrasound guidance combined with digital subtraction angiography(DSA)to completely remove the occluder,accumulating some *** SUMMARY The patient underwent left atrial appendage occlusion surgery in our hospital due to atrial *** the surgery,the occluder fell off and became free in the left ventricle,which is very *** innovatively used ultrasound guidance,combined with DSA,and interventional surgery to successfully capture the free occluder using a catcher,completely remove it,and then re implant a new left atrial appendage *** the surgery,the patient recovered very *** The size selection of the occluder is slightly conservative,and the shape of the left atrial appendage opening is irregular.

关键词： Left atrial appendage occluder Detachment Ultrasound combined with digital subtraction angiography Interventional operation Successfully captured Case report

Preparation of Laser Cladding Coating Undercooling Cu-based Alloy and Co on Non-equilibrium Solidification Structure

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Journal of Wuhan University of Technology(Materials Science) 2024年第2期39卷 463-472页

作者：田徐铭 CAO Shichao HOU kai HOU Xiaopeng WANG Hongfu 张煜 Department of Outpatient Xinzhou People’s HospitalXinzhou 034099China School of Mechanical Engineering North University of ChinaTaiyuan 030051China Department of Neurosurgery Xinzhou People’s HospitalXinzhou 034099China Department of Orthopedics Xinzhou People’s HospitalXinzhou 034099China

The effect of the gradient content of Co element on the solidification process of Cu-based alloy under deep under cooling conditions was *** non-equilibrium solidification structure of the under cooled alloy samples were *** is found that the rapidly solidified alloy has undergone twice grain refinement during the undercooling *** and significance of the maximum undercooling refinement structure of Cu60Ni35Co5 at T=253 K were ***-density defects were observed,such as dislocations,stacking faults networks,and twinning *** standard FCC diffraction pattern represents that it is still a single-phase *** on the metallographic diagram,EBSD and TEM data analysis,it is illustrated that the occurrence of grain refinement under high undercooling is due to stress induced *** addition,the laser cladding technology is used to coat Co-based alloy(Stellite12) coating on 304 stainless steel substrate;the microstructure of the coating cross-section was *** was found that the microstructure of the cross-section is presented as columnar crystals,planar crystals,and disordered growth direction,so that the coating has better hardness and wear *** electrochemical corrosion of the substrate and coating,it can be seen that the Co and Cr elements present in the coating are more likely to form a dense passivation film,which improved the corrosion resistance of the coating.

关键词： non-equilibrium solidification structure undercooling recrystallization laser cladding coating

Pricing and production strategies in remanufacturing from the perspectives of supply chain: Review and future directions

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Frontiers of Engineering Management 2024年第1期11卷 1-15页

作者： kai LI Yan LI Nenggui ZHAO School of Management Hefei University of TechnologyHefei 230009China Key Laboratory of Process Optimization and Intelligent Decision-making Ministry of EducationHefei 230009China

Remanufacturing is widely recognized as beneficial to the environment and a circular economy. However, remanufacturing is more complex than traditional manufacturing due to the effects of government policy, uncertainty of consumer preferences, competition and cooperation among firms, and so on. These factors motivate academics to optimize remanufacturing outcomes, especially for product pricing and production. This study reviews the published literature on pricing and production strategies in remanufacturing from four perspectives of supply chain, namely, government policy, consumer characteristics, relationships among firms, and supply chain structures. Review results can benefit scholars/practitioners in the future by highlighting the challenges and opportunities in remanufacturing strategies.

关键词： remanufacturing reverse and closed-loop supply chain circular economy