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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 793-807页

作者： Jinpeng hu Tao Sun Fujun Cao Yifu Shen Zhiyuan yang Chan Guo College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics(NUAA)Nanjing 210016China

Submerged friction stir processing(SFSP)with flowing water was employed to alleviate the porosities and coarse-grained structure introduced by wire-arc *** a result,uniform and ultrafine grained(UFG)structure with average grain size of 0.83μm was achieved with the help of sharply reduced heat input and holding time at elevated *** optimized UFG structure enabled a superior combination of strength and ductility with high ultimate tensile strength and elongation of 273.17 MPa and 15.39%.Specifically,grain refinement strengthening and decentralized θ(Al_(2)Cu)phase in the sample subjected to SFSP made great contributions to the enhanced *** addition,the decrease in residual stresses and removal of pores substantially enhance the *** rates of cooling and low temperature cycling,which are facilitated by the water-cooling environment throughout the machining process,are vital in obtaining superior *** work provides a new method for developing a uniform and UFG structure with excellent mechanical properties.

关键词： Submerged friction stir processing Wire-arc additive manufacturing Al-Cu alloy Residual stress Strengthening and toughening mechanism Ultrafine grained microstructure

Experimental Study of Fuel-Air Mixing and Dilution Jets on Outlet Temperature Distribution in a Small Gas Turbine Combustor

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Journal of Thermal Science 2024年第5期33卷 1883-1896页

作者： CAI Wenzhe WU Jing hu Yingqi yang Zhiqiang XUE Xin LIN Yuzhen National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics Research Institute of Aero-EngineBeihang UniversityBeijing 100191China Beijing Institute of Power Machinery Beijing 100074China School of Energy and Power Engineering Beihang UniversityBeijing 100191China

Experimental analysis was conducted to study the impact of fuel-air mixing and dilution jet on the temperature distribution in a small gas turbine combustor using various optical diagnostic *** strength and velocity of the swirler at the venturi exit were adjusted to modify the fuel-air mixture,which is presumed to dominate the heat release of the main combustion ***,the dilution hole configuration,including the number and size of the holes,was varied to investigate the dilution effect on outlet temperature *** optical diagnostic techniques,such as particle image velocimetry,planar Mie scattering,and OH~*chemiluminescence,were used to measure the flow field,fuel spray distribution,and flame structure,respectively.A reduction in swirling strength led to a decrease in the average flow rate in the throat,which improved the structure and symmetry of the axial vortex system in the sleeve,enhanced the mixing of fuel and gas in the dome swirling air,and ultimately,improved the temperature uniformity of the heat release *** to larger and sparse dilution jets,smaller and dense dilution jets tended to generate hot spots shifted towards the radial middle area.

关键词： small gas turbine combustor fuel-air mixing outlet temperature distribution dilution jet laser diagnostics

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Depressive semantic awareness from vlog facial and vocal streams via spatio-temporal transformer

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Digital Communications and Networks 2024年第3期10卷 577-585页

作者： Yongfeng Tao Minqiang yang Yushan Wu Kevin Lee Adrienne Kline Bin hu School of Information Science and Engineering Lanzhou UniversityLanzhouChina The School of Accounting Auditing and TaxationBusiness SchoolUNSW SydneyAustralia Department of Preventive Medicine Northwestern UniversityChicagoILUnited States

With the rapid growth of information transmission via the Internet,efforts have been made to reduce network load to promote *** such application is semantic computing,which can extract and process semantic *** media has enabled users to share their current emotions,opinions,and life events through their mobile ***,people suffering from mental health problems are more willing to share their feelings on social ***,it is necessary to extract semantic information from social media(vlog data)to identify abnormal emotional states to facilitate early identification and *** studies do not consider spatio-temporal information when fusing multimodal information to identify abnormal emotional states such as *** solve this problem,this paper proposes a spatio-temporal squeeze transformer method for the extraction of semantic features of ***,a module with spatio-temporal data is embedded into the transformer encoder,which is utilized to obtain a representation of spatio-temporal ***,a classifier with a voting mechanism is designed to encourage the model to classify depression and non-depression *** are conducted on the D-Vlog *** results show that the method is effective,and the accuracy rate can reach 70.70%.This work provides scaffolding for future work in the detection of affect recognition in semantic communication based on social media vlog data.

关键词： Emotional computing Semantic awareness Depression recognition Vlog data

Adaptive observer-based integral event-triggered antivibration control of a full aircraft active landing gear system with irregular runway excitations

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Science China(Information Sciences) 2024年第6期67卷 248-261页

作者： Wenxiao hu Chenglong DU Fanbiao LI Xinmin CHEN Chunhua yang Weihua GUI School of Automation Central South University Research Center in System Engineering for Special Aircrafts Ningbo Institute of Materials Technology and EngineeringChinese Academy of Sciences

This study addresses the antivibration issue of a full aircraft active landing gear system(LGS)under landing impact and runway excitations via a novel adaptive observer-based integral event-triggered control method. First, a full aircraft active LGS comprising a front gear and two synchronized main left and right gears with active suspensions is established, where the information exchange among them is not implemented directly. Second, two adaptive observers are designed separately for the front and main LGSs to identify the varying damping parameters and estimate the system states simultaneously. Third, estimated states are transmitted to a shared network through a novel integral event-triggered mechanism(I-ETM);thus, the front and main LGSs are interconnected, and a networked control scheme for the aircraft LGS is constructed. Additionally, the integrated active control law is designed with the aid of the transmitted states of the front and main LGSs, enhancing the robustness against the pitch vibration of the ***, the L2-stability of the hybrid system is guaranteed to depress the vertical vibration effect of the landing impact and irregular runway excitations, thus improving passenger safety and comfort. Moreover,a codesign method is provided to obtain feasible solutions to the gain matrices of the observers and controllers simultaneously. Simulation and comparison results are presented to illustrate the effectiveness and superiority of the proposed control scheme in antivibration and saving communication resources.

关键词： aircraft active landing gear antivibration control integral event-triggered mechanism adaptive observer \({\cal L}_{2}\)-stability

New insights into the pre-lithiation kinetics of single-crystalline Ni-rich cathodes for long-life Li-ion batteries

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Green Energy & Environment 2024年第3期9卷 556-564页

作者： Qiang Han Lele Cai Zhaofeng yang Yanjie hu Hao Jiang Chunzhong Li Shanghai Engineering Research Center of Hierarchical Nanomaterials School of Chemical EngineeringEast China University of Science and TechnologyShanghai200237China Key Laboratory for Ultrafine Materials of Ministry of Education School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai200237China

Developing single-crystalline Ni-rich cathodes is an effective strategy to improve the safety and cycle life of Li-ion batteries(LIBs).However,the easy-to-loss of Li and O in high-temperature lithiation results in unsatisfactory ordered layered structure and ***,we demonstrate the synthesis of highly-ordered and fully-stoichiometric single-crystalline LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)cathodes by the regulation of pre-lithiation *** well-balanced pre-lithiation kinetics have been proved to greatly improve the proportion of layered phase in the intermediate by inhibiting the formation of metastable spinel phase,which promoted the rapid transformation of the intermediate into highly-ordered layered SC-NCM83 in the subsequent lithiation *** coating a layer of Li_(2)O–B_(2)O_(3),the resultant cathodes deliver superior cycling stability with 90.9%capacity retention at 1C after 300 cycles in pouch-type full *** enhancement mechanism has also been *** findings exhibit fundamental insights into the pre-lithiation kinetics process for guiding the synthesis of high-quality singlecrystalline Ni-rich cathodes.

关键词： Single-crystalline cathode Ni-rich oxides Pre-lithiation Li-ion batteries Surface modification

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The structure of TRAF7 coiled-coil trimer provides insight into its function in zebrafish embryonic development

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Journal of Molecular Cell Biology 2024年第1期16卷 43-53页

作者： Xiaozhen Song Ruixing hu Yi Chen Man Xiao Hong Zhang Shengnan Wu qing Lu Molecular Diagnostic Laboratory Shanghai Children’s HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200040China Bio-X Institutes Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders(Ministry of Education)Shanghai Jiao Tong UniversityShanghai 200030China Laboratory of Development and Diseases and State Key Laboratory for Medical Genomics Shanghai Institute of HematologyRuĳin HospitalShanghai JiaoTong University School of MedicineShanghai 200025China

TRAF7 serves as a crucial intracellular adaptor and E3 ubiquitin ligase involved in signal transduction pathways,contributing to immune responses,tumor progression,and embryonic *** mutations within the coiled-coil(CC)domain and WD40 repeat domain of TRAF7 could cause brain tumors,while germline pathogenic mutations contribute to severe developmental ***,the precise molecular mechanism underlying TRAF7 involvement in embryonic development remains *** this study,we employed zebrafish as an in vivo model ***7 knock down caused defects in zebrafish embryonic *** determined the crystal structure of TRAF7 CC domain at 3.3Åresolution and found that the CC region trimerization was essential for TRAF7 functionality during zebrafish embryonic ***,disease-causing mutations in TRAF7 CC region could impair the trimer formation,consequently impacting early embryonic development of ***,our study sheds light on the molecular mechanism of TRAF7 CC trimer formation and its pivotal role in embryonic development.

关键词： TRAF7 coiled-coil domain crystal structure trimerization embryonic development

A low-cost and high-strength basalt/carbon fiber reinforced polymer improved by imitating tree-root micro/nano aramid short fiber

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Chinese Journal of Aeronautics 2024年第10期37卷 526-538页

作者： Guangming yang Yanan LYU Fei CHENG Jiaxin HE Shihao ZUO Wenyi huANG Yunsen hu Xiaozhi hu Xi CHEN Shock and Vibration of Engineering Materials and Structures Key Lab of Sichuan Province Southwest University of Science and TechnologyMianyang 621010China Engineering Research Center of Biomass Materials Ministry of EducationSouthwest University of Science and TechnologyMianyang 621010China School of Materials and Chemistry Southwest University of Science and TechnologyMianyang 621010China Institute of Automation Chinese Academy of SciencesBeijing 100190China School of Artificial Intelligence University of Chinese Academy of SciencesBeijing 100101China School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Department of Mechanical Engineering University of Western AustraliaPerth 6009Australia

The high-strength Basalt Carbon Fiber Reinforced Polymer(BCFRP)composites had been manufactured by guiding Imitating Tree-root Micro/Nano Aramid Short Fiber(ITMNASF)into the interlayer of Basalt Fiber(BF)and Carbon Fiber(CF)plies to form thin interleaving,and various mass proportions of IT-MNASF were designed to discuss the reinforcing effect on the BCFRP heterogeneous *** results of three points bending tests showed that flexural strength and energy absorption of 4wt%IT-MNASF reinforced BCFRP heterogeneous composites had been improved by 32.4%and 134.4%respectively compared with that of unreinforced *** 4wt%IT-MNASF reinforced BCFRP specimens showed both a greater strength and a lower cost(reduced by 31%around)than that of plain CFRP composites.X-ray micro-computed tomography scanning results exhibited that the delamination-dominated failure of plain BCFRP composites was changed into multi-layer BF and CF fabrics *** reinforcing mechanism revealed that the introduced IT-MNASF could construct quasi-vertical fiber bridging,and it was used as"mechanical claws"to grasp adjacent fiber layers for creating a stronger mechanical interlocking,and this effectively improved resin-rich region and interfacial transition region at the *** simple and effective IT-MNASF interleaving technique was very successful in low-cost and high-strength development of BCFRP heterogeneous composites.

关键词： Basalt carbon fiber reinforced polymer Micro/nano aramid fiber Fiber bridging Strength improvement Low-cost substitution

Optimizing magnetoelastic properties by machine learning and high-throughput micromagnetic simulation

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Rare Metals 2024年第5期43卷 2251-2262页

作者： Jian-hu Gong Zheng-Ming Zhang Cheng-Liang Zhang Peng-Qiang hu Chao Zhou Dun-hui Wang Sen yang Division of Microelectronic Materials and Devices Hangzhou Dianzi UniversityHangzhou 310018China School of Physics MOEKey Laboratory forNonequilibrium Synthesis and Modulation of Condensed Matter and State Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an 710049China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing210093China

Magnetoelastic couplings in giant magnetostrictive materials(GMMs)attract significant interests due to their extensive applications in the fields of spintronics and energy harvesting *** the role of the selection of materials and the response to external fields is essential for attaining desired functionality of a ***,machine learning(ML)models are conducted to predict saturation magnetostrictions(λ_(s))in RFe_(2)-type(R=rare earth)GMMs with different *** to ML-predicted composition–λsrelations,it is discovered that the values ofλshigher than1100×10^(-6)are almost situated in the composition space surrounded by 0.26≤x≤0.60 and 1.90≤y≤2.00 for the ternary compounds of Tb_(x)Dy_(1-x)Fe_(y).Assisted by ML predictions,the compositions are further narrowed down to the space surrounded by 0.26≤x≤0.32 and 1.92≤y≤1.97 for the excellent piezomagnetic(PM)performance in the Tb_(x)Dy_(1-x)Fe_(y)based PM device through our developed high-throughput(HTP)micromagnetic simulation(MMS)***,high sensitivities up to10.22-13.61 m T·MPa^(-1)are observed in the optimized range within which the available experimental data fall *** work not only provides valuable insights toward understanding the mechanism of magnetoelastic couplings,but also paves the way for designing and optimizing highperformance magnetostrictive materials and PM sensing devices.

关键词： Magnetostriction Piezomagnetic effect Machine learning Micromagnetic simulation

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Iterative physical optics method based on efficient occlusion judgment with bounding volume hierarchy technology

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Journal of Electronic Science and Technology 2024年第1期22卷 1-12页

作者： yang Su Yu-Mao Wu Jun hu Key Laboratory for Information Science of Electromagnetic Waves(MoE) School of Information Science and TechnologyFudan UniversityShanghai200433China School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China

This paper builds a binary tree for the target based on the bounding volume hierarchy technology,thereby achieving strict acceleration of the shadow judgment process and reducing the computational complexity from the original O(N^(3))to O(N^(2)logN).Numerical results show that the proposed method is more efficient than the traditional *** is verified in multiple examples that the proposed method can complete the convergence of the ***,the proposed method avoids the error of judging the lit-shadow relationship based on the normal vector,which is beneficial to current iteration and *** with the brute force method,the current method can improve the simulation efficiency by 2 orders of *** proposed method is more suitable for scattering problems in electrically large cavities and complex scenarios.

关键词： Bounding volume hierarchy Cavity scattering Iterative physical optics(IPO)

Theoretical and experimental research on static stiffness,performance,and lift-off characteristics of multi-layer gas foil thrust bearings

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Friction 2024年第11期12卷 2458-2479页

作者： yang hu Pengjing DING Fangling WU Xiaojing WANG Bo LIANG Yonggang MENG School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200072China Aviation Key Laboratory of Science and Technology on Aero Electromechanical System Integration Nanjing Engineering Institute of Aircraft SystemsNanjing 211106China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

In this study,a new comprehensive fully coupled elastic–hydrodynamic model is developed for a multi-layer gas foil thrust bearing(GFTB).The interaction effects among the top foil,back board,middle foil,and bottom foil,as well as the Coulomb friction effect,are *** stiffness and static characteristics obtained by the experimental and theoretical approaches are in good agreement,which verifies the accuracy of the *** contribution of each foil layer to the overall stiffness and the load-carrying mechanism are *** effects of the load,preload,and rotational speed on the static performance are investigated ***,start–stop tests are performed to achieve the lift-off speed,start-up torque,and shut-down torque under various operating conditions.

关键词： multi-layer gas foil thrust bearing(GFTB) load carrying mechanism static performance