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Influence of bolt dynamic installation on topography characteristics and mechanical behaviors of CFRP interference-fit bolted joints

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Chinese Journal of Aeronautics 2024年第2期37卷 482-500页

作者： Xiaohe wang Zengqiang CAO Yuehaoxuan wang Yingjiang GUO School of Mechanical Engineering Northwestern Polytechnical UniversityXi’an 710072China NPU Xuhang Electromagnetic Technology Co. Ltd.Xi’an 710100China

As the controlled research of Dynamic Installation(DI)and Static Installation(SI),a new interference installation method was developed based on electromagnetic loading to enhance the mechanical properties of composite *** different interference-fit sizes were considered,ranging from a net fit to 2.0%.The experiments were conducted to evaluate the installation resistance and the mechanical behavior of the joint under external ***,an FFA model to model the stress distribution and damage behavior of the bolt-hole contact interface was *** load-displacement curve and damage modes of experiments were used to verify the FEA *** results show that the installation resistance during DI process was remarkably lower than that of SI process corresponding to all interference-fit sizes,and the stress amplitudes induced by interference were larger and widely *** damage of the hole wall was positively correlated with interference fit size,but DI can significantly reduce the damage compared to *** performance tests,DI enhanced the static bearing capacity and extended longer fatigue life of the joints than *** methods can be an effective way to achieve highly reliable interference joints in composite structures.

关键词： Carbon Fiber-Reinforced Polymer(CFRP) Bolted joints Interference-fit Electromagnetic installation Finite Element Analysis(FEA) Damage mechanics Bearing behavior

Surface modification by ligand growth strategy for dense copper bismuth film as photocathode to enhance hydrogen production activity

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Frontiers in Energy 2024年第1期18卷 89-100页

作者： Zhouzhou wang Qingwei WU Jieming wang Ying YU Institute of Nanoscience and Nanotechnology College of Physical Science and TechnologyCentral China Normal UniversityWuhan 430079China

Hydrogen production from photoelectrochemical(PEC)water splitting has been regarded as a promising way to utilize renewable and endless solar ***,semiconductor film grown on photoelectrode suffers from numerous challenges,leading to the poor PEC ***,a straightforward sol-gel method with the ligand-induced growth strategy was employed to obtain dense and homogeneous copper bismuthate photocathodes for PEC hydrogen evolution *** various characterizations,it was found that the nucleation and surface growth of CuBi_(2)O_(4)layer induced by 2-methoxyethanol ligand(2-CuBi_(2)O_(4))demonstrated a decent crystallinity and coverage,as well as a large grain size and a low oxygen vacancy concentration,leading to the good ability of light absorption and carrier ***,under simulated sunlight irradiation(AM1.5G,100 mW/cm^(2)),the 2-CuBi_(2)O_(4)photocathode achieved an enhanced photocurrent density of−1.34 mA·cm^(−2)at 0.4 V versus the reversible hydrogen electrode and a promising applied bias photon-to-current efficiency of 0.586%.This surface modification by ligand growth strategy will shed light on the future design of advanced photoelectrodes for PEC water splitting.

关键词： copper bismuthate photocathode ligand growth strategy dense film PEC

CEOs’Diverse Career Experiences and the Effectiveness of Compensation Contracts:Evidence from Compensation Stickiness

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Journal of Systems Science and Systems Engineering 2024年第1期33卷 52-76页

作者： Shimin Sun Yongheng wang Yawen wang Mengyu Mao School of Business Administration Northeastern UniversityShenyang110169China

CEO compensation stickiness represents an important indicator to measure the effectiveness of compensation *** study uses CEO career experience data and compensation stickiness data from Shanghai and Shenzhen A-share listed companies from 2015 to 2020 to investigate the compensation contracts’effectiveness of CEOs with diverse career *** findings are as follows:1)Compensation stickiness is more pronounced for CEOs with diverse career *** to the mechanism test,these CEOs with diverse career experiences can obtain compensation incentives by reducing corporate uncertainty perception and improving total factor *** approach leads to increased compensation stickiness and the effectiveness of compensation *** with diverse career experiences may receive excess compensation by raising agency costs,which intensifies compensation stickiness and weakens the effectiveness of compensation contracts.2)Compensation stickiness of CEOs with diverse career experiences is more significant in companies with lower investor protection,which brings about less effective compensation *** contrast,in companies with higher diversification,the compensation stickiness of CEOs with diverse career experiences is more significant,which delivers more effective compensation *** conclusions deepen the research of CEO compensation contracts and provide a helpful reference for CEO compensation management practices.

关键词： CEOs’diverse career experiences effectiveness of compensation contracts compensation stickiness agency problems incentive mechanisms

Improving Fatigue Properties of 316L Stainless Steel Welded Joints by Surface Spinning Strengthening

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 840-854页

作者： Dongqiqiong wang Qiang wang Xiaowu Li Zhefeng Zhang Department of Materials Physics and Chemistry School of Materials Science and Engineeringand Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education)Northeastern UniversityShenyang 110819China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China College of Light Industry Liaoning UniversityShenyang 110036China

The surface spinning strengthening(3S)mechanism and fatigue life extension mechanism of 316L stainless steel welded joint were systematically elucidated by microstructural analyses and mechanical *** indicate that surface gradient hardening layer of approximately 1 mm is formed in the base material through grain fragmentation and deformation twin strengthening,as well as in the welding zone composed of deformedδ-phases and *** fatigue strength of welded joint after 3S significantly rises by 32%(from 190 to 250 MPa),which is attributed to the effective elimination of surface geometric defects,discrete refinement ofδ-Fe phases and the appropriate improvement in the surface strength,collectively mitigating strain localization and surface fatigue damage within the gradient strengthening *** redistributed fineδ-Fe phases benefited by strong stress transfer of 3S reduce the risk of surface weak phase cracking,causing the fatigue fracture to transition from microstructure defects to crystal defects dominated by slip,further suppressing the initiation and early propagation of fatigue cracks.

关键词： 316L stainless steel Welded joint Surface spinning strengthening Nanotwin Fatigue life

A star identification algorithm for rolling shutter exposure based on Hough transform

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Chinese Journal of Aeronautics 2024年第6期37卷 319-330页

作者： Tao wang Gangyi wang Xinguo WEI Yongyong LI School of Instrumentation and Optoelectronic Engineering Beihang UniversityBeijing 100191China

The star identification algorithm usually identifies stars by angular distance ***,under high dynamic conditions,the rolling shutter effect distorts the angular distances between the measured and true star positions,leading to plethoric false matches and requiring complex and time-consuming verification for star *** identification rate hinders the application of low-noise and cost-effective rolling shutter image *** this work,we first study a rolling shutter distortion model of angular distances between stars,and then propose a novel three-stage star identification algorithm to identify distorted star images captured by the rolling shutter star *** first stage uses a modified grid algorithm with adaptive error tolerance and an expanded pattern database to efficiently eliminate spurious *** second stage performs angular velocity estimation based on Hough transform to verify the matches that follow the same distortion *** third stage applies a rolling shutter error correction method for further *** the simulation and night sky image test demonstrate the effectiveness and efficiency of our algorithm under high dynamic *** accuracy of angular velocity estimation method by Hough transform is evaluated and the root mean square error is below 0.5(°)/*** algorithm achieves a 95.7% identification rate at an angular velocity of 10(°)/s,which is much higher than traditional algorithms.

关键词： Star trackers Star identification Rolling shutter Angular velocity estimation Hough transform

Optimization Control of Multi-Mode Coupling All-Wheel Drive System for Hybrid Vehicle

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 340-355页

作者： Lipeng Zhang Zijian wang Liandong wang Changan Ren School of Vehicle and Energy Yanshan UniversityQinhuangdao 066004China

The all-wheel drive(AWD)hybrid system is a research focus on high-performance new energy vehicles that can meet the demands of dynamic performance and passing *** optimization of the power and economy of hybrid vehicles becomes an issue.A unique multi-mode coupling(MMC)AWD hybrid system is presented to realize the distributed and centralized driving of the front and rear axles to achieve vectored distribution and full utilization of the system power between the axles of *** on the parameters of the benchmarking model of a hybrid vehicle,the best model-predictive control-based energy management strategy is ***,the drive system model was built after the analysis of the MMC-AWD’s drive ***,three fundamental strategies were established to address power distribution adjustment and battery SOC maintenance when the SOC changed,which was followed by the design of a road driving force ***,the energy consumption rate in the average time domain was processed before designing the minimum fuel consumption controller based on the equivalent fuel consumption ***,the advantage of the MMC-AWD was confirmed by comparison with the dynamic performance and economy of the BYD Song PLUS *** findings indicate that,in comparison to the comparative hybrid system at road adhesion coefficients of 0.8 and 0.6,the MMC-AWD’s capacity to accelerate increases by 5.26%and 7.92%,*** the road adhesion coefficient is 0.8,0.6,and 0.4,the maximum climbing ability increases by 14.22%,12.88%,and 4.55%,*** a result,the dynamic performance is greatly enhanced,and the fuel savings rate per 100 km of mileage reaches 12.06%,which is also very *** proposed control strategies for the new hybrid AWD vehicle can optimize the power and economy simultaneously.

关键词： Hybrid vehicle All-wheel drive Multi-mode coupling Energy management Model predictive control

Solid Bi_(2)O_(3)-derived nanostructured metallic bismuth with high formate selectivity for the electrocatalytic reduction of CO_(2)

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International Journal of Minerals,Metallurgy and Materials 2024年第4期31卷 803-811页

作者： Xiaoyan wang Safeer Jan Zhiyong wang Xianbo Jin College of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power SourcesWuhan UniversityWuhan 430072China Engineering Research Center of Organosilicon Compounds&Materials Ministry of EducationWuhan 430072China

CO_(2) electrochemical reduction(CO_(2)ER)is an important research area for carbon ***,available catalysts for CO_(2) reduction are still characterized by limited stability and ***,metallic bismuth(Bi)has emerged as a promising catalyst for CO_(2) ***,we report the solid cathode electroreduction of commercial micronized Bi2O3as a straightforward approach for the preparation of nanostructured ***-1.1 V versus reversible hydrogen electrode in a KHCO3aqueous electrolyte,the resulting nanostructure Bi delivers a formate current density of~40 mA·cm^(-2) with a current efficiency of~86%,and the formate selectivity reaches97.6% at-0.78 *** nanosized Bi2O3as the precursor can further reduce the primary particle sizes of the resulting Bi,leading to a significantly increased formate selectivity at relatively low *** high catalytic activity of nanostructured Bi is attributable to the ultrafine and interconnected Bi nanoparticles in the nanoporous structure,which exposes abundant active sites for CO_(2) electrocatalytic reduction.

关键词： bismuth carbon dioxide electrocatalysis formate solid electroreduction

Dynamic performance and parameter optimization of a half-vehicle system coupled with an inerter-based X-structure nonlinear energy sink

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 85-110页

作者： Yong wang Peili wang Haodong MENG Liqun CHEN .Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013Jiangsu ProvinceChina Guangxi Key Laboratory of Automobile Components and Vehicle Technology Guangxi University of Science and TechnologyLiuzhou 545006Guangxi Zhuang Autonomous RegionChina School of Automotive Engineering Changzhou Institute of TechnologyChangzhou 213032Jiangsu ProvinceChina Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai Frontier Science Center of MechanoinformaticsShanghai Institute of Applied Mathematics and MechanicsSchool of Mechanics and Engineering ScienceShanghai UniversityShanghai 200444China

Inspired by the demand of improving the riding comfort and meeting the lightweight design of the vehicle, an inerter-based X-structure nonlinear energy sink(IXNES) is proposed and applied in the half-vehicle system to enhance the dynamic performance. The X-structure is used as a mechanism to realize the nonlinear stiffness characteristic of the NES, which can realize the flexibility, adjustability, high efficiency, and easy operation of nonlinear stiffness, and is convenient to apply in the vehicle suspension, and the inerter is applied to replacing the mass of the NES based on the mass amplification characteristic. The dynamic model of the half-vehicle system coupled with the IX-NES is established with the Lagrange theory, and the harmonic balance method(HBM) and the pseudo-arc-length method(PALM) are used to obtain the dynamic response under road harmonic excitation. The corresponding dynamic performance under road harmonic and random excitation is evaluated by six performance indices, and compared with that of the original half-vehicle system to show the benefits of the IX-NES. Furthermore, the structural parameters of the IX-NES are optimized with the genetic algorithm. The results show that for road harmonic and random excitation, using the IX-NES can greatly reduce the resonance peaks and root mean square(RMS) values of the front and rear suspension deflections and the front and rear dynamic tire loads, while the resonance peaks and RMS values of the vehicle body vertical and pitching accelerations are slightly *** the structural parameters of the IX-NES are optimized, the vehicle body vertical and pitching accelerations of the half-vehicle system could reduce by 2.41% and 1.16%,respectively, and the other dynamic performance indices are within the reasonable ***, the IX-NES combines the advantages of the inerter, X-structure, and NES, which improves the dynamic performance of the half-vehicle system and provides an effective option for vibrati

关键词： inerter X-structure nonlinear energy sink(NES) half-vehicle system dynamic performance

Anisotropic tribology and electrification properties of slidingmode triboelectric nanogenerator with groove textures

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Friction 2024年第8期12卷 1828-1837页

作者： Weixu YANG Jieyang wang Xiaoli wang Ping CHEN Department of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China Department of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China

Sliding-mode triboelectric nanogenerator(S-TENG)is based on the coupling of triboelectrification and electrostatic induction,converting electrical energy from sliding *** micro-textures into the sliding surface,and adjusting the angle between the texture and sliding direction(direction angle)may achieve performance anisotropy,which provides novel ideas for optimizing the tribology and electrification performance of *** guide the performance optimization based on the anisotropy,in this paper,groove micro-textures were fabricated on the surface of S-TENG,and anisotropic tribology and electrification performance were obtained through changing the direction *** on the surface analysis and after-cleaning tests,the mechanism of the anisotropy was *** is shown that the anisotropy of friction coefficient can be attributed to the changes of texture edge induced resistance and groove captured wear debris,while the voltage anisotropy is due to the variations of debris accumulated on the sliding interface and the resulting charge *** the selected 0°–90°direction angles,S-TENG at angle of 90°exhibits relatively small stable friction coefficient and high open-circuit voltage,and thus it is recommended for the performance *** open-circuit voltage is not directly associated with the friction coefficient,but closely related to the wear debris accumulated on the sliding *** study presents a simple and convenient method to optimize the performance of S-TENG,and help understand the correlation between its tribology and electrical performance.

关键词： sliding-mode triboelectric nanogenerator groove textures direction angle performance anisotropy tribology&electrification properties