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Frontiers of Structural and Civil Engineering 2024年第5期18卷 788-804页

作者： Dexiang li Jingyu huang College of Civil Engineering Tongji UniversityShanghai 200092China National Maglev Transportation Engineering R&D Center Tongji UniversityShanghai 201804China

The high-speed maglev vehicle/guideway coupled model is an essential simulation tool for investigating vehicle dynamics and mitigating coupled *** improve its accuracy efficiently,this study investigated a hierarchical model updating method integrated with field ***,a high-speed maglev vehicle/guideway coupled model,taking into account the real effect of guideway material properties and elastic restraint of bearings,was developed by integrating the finite element method,multi-body dynamics,and electromagnetic levitation ***,simultaneous in-site measurements of the vehicle/guideway were conducted on a high-speed maglev test line to analyze the system response and structural modal *** the hierarchical updating,an Elman neural network with the optimal Latin hypercube sampling method was used to substitute the FE guideway model,thus improving the computational *** multi-objective particle swarm optimization algorithm with the gray relational projection method was applied to hierarchically update the parameters of the guideway layer and magnetic force layer based on the measured modal parameters and the electromagnet vibration,***,the updated coupled model was compared with the field measurements,and the results demonstrated the model’s accuracy in simulating the actual dynamic response,validating the effectiveness of the updating method.

关键词： high-speed maglev vehicle/guideway coupled model field measurement model updating neural network multi-objective optimization

Automatic bug assignments without texts: a study

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Frontiers of Computer Science 2024年第4期18卷 211-213页

作者： Zexuan li Kaixin huang Department of Computer Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

1 Introduction Automatic bug assignment has been well-studied in the past *** textual bug reports usually describe the buggy phenomena and potential causes,engineers highly depend on these reports to fix ***,researchers spend much effort on processing bug reports,aiming for obtaining key information and/or clues for reproducing bugs,analyzing their root causes,assigning them to developers/maintainers,and fixing these ***,our previous research[1]reveals that noises in texts bring adverse impacts to automatic bug assignments unexpectedly,mainly due to insufficiency of classical Natural Language Processing(NLP)techniques.

关键词： bug assignment maintain

Feature Matching via Topology-Aware Graph Interaction Model

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 113-130页

作者： Yifan Lu Jiayi Ma Xiaoguang Mei Jun huang Xiao-ping Zhang the Electronic Information School Wuhan UniversityWuhan 430072China IEEE Tsinghua Berkeley Shenzhen Institute Shenzhen 518071China the Department of Electrical Computer and Biomedical EngineeringToronto Metropolitan UniversityToronto ON M5B 2K3Canada

Feature matching plays a key role in computer vision. However, due to the limitations of the descriptors, the putative matches are inevitably contaminated by massive *** paper attempts to tackle the outlier filtering problem from two aspects. First, a robust and efficient graph interaction model,is proposed, with the assumption that matches are correlated with each other rather than independently distributed. To this end, we construct a graph based on the local relationships of matches and formulate the outlier filtering task as a binary labeling energy minimization problem, where the pairwise term encodes the interaction between matches. We further show that this formulation can be solved globally by graph cut algorithm. Our new formulation always improves the performance of previous localitybased method without noticeable deterioration in processing time,adding a few milliseconds. Second, to construct a better graph structure, a robust and geometrically meaningful topology-aware relationship is developed to capture the topology relationship between matches. The two components in sum lead to topology interaction matching(TIM), an effective and efficient method for outlier filtering. Extensive experiments on several large and diverse datasets for multiple vision tasks including general feature matching, as well as relative pose estimation, homography and fundamental matrix estimation, loop-closure detection, and multi-modal image matching, demonstrate that our TIM is more competitive than current state-of-the-art methods, in terms of generality, efficiency, and effectiveness. The source code is publicly available at http://***/YifanLu2000/TIM.

关键词： Feature matching graph cut outlier filtering topology preserving

Design optimization of a hexapod vibration isolation system for electro-optical payload

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Chinese Journal of Aeronautics 2024年第2期37卷 330-342页

作者： Jing li Weipeng li Xiaoyan ZHANG Hai huang School of Astronautics Beihang UniversityBeijing 100191China

The electro-optical payloads on mobile platforms generally suffer undesirable vibrations generated by maneuvers and *** vibrations are in six degrees of freedom and cause line-of-sight jitters,resulting in image blurring and loss of tracking *** this paper,a Hexapod Vibration Isolation System(HVIS)is proposed and optimized to solve this *** optimization aims to centralize and minimize the natural frequencies of HVIS,for expanding the vibration isolation bandwidth and improving the vibration isolation in the higher frequency *** that the design space for HVIS is limited and interfered with the frames of the mobile platform,a non-collision algorithm is proposed and applied in the optimization to obtain the feasible optimal *** optimization result shows that the natural frequency bandwidth has been reduced by 42.9%,and the maximum natural frequency is reduced by 30.2%.The prototypes of initial and optimal designs are manufactured and *** simulated and experimental results demonstrate the validity of the optimization,and the optimal design provides a maximum of 15 dB more isolation in rotation direction than the initial design.

关键词： Electro-optical payload Vibrations Isolation system Hexapod Optimization Non-collision design

Association between abnormal default mode network homogeneity and sleep disturbances in major depressive disorder

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General Psychiatry 2024年第2期37卷 234-241页

作者： Muzhi huang Yangpan Ou Huabing li Feng liu ping li Jingping Zhao Bing Lang Wenbin Guo Department of Psychiatry The Second Xiangya Hospital of Central South University National Clinical Research Center for Mental Disordersand National Center for Mental DisordersChangshaHunanChina Department of Radiology The Second Xiangya Hospital of Central South UniversityChangshaHunanChina Department of Radiology Tianjin Medical University General HospitalHepingTianjinChina Qiqihar Medical University QiqihaerHeilongjiangChina

Background Sleep disturbance is a common comorbidity of major depressive disorder(MDD).However,network homogeneity(NH)changes of the default mode network(DMN)in MDD with sleep disturbances are *** The purpose of this study was to probe the abnormal NH in the DMN in MDD with sleep disturbances and to reveal the differences between MDD with or without sleep *** Twenty-four patients with MDD and sleep disturbances(Pa_s),33 patients with MDD without sleep disturbances(Pa_ns)and 32 healthy controls(HCs)were recruited in this ***-state functional imaging data were analysed using *** Compared with Pa_ns and HCs,Pa_s showed decreased NH in the left superior medial prefrontal cortex and increased NH in the right *** was a negative correlation between NH in the left superior medial prefrontal cortex and sleep disturbances(r=−0.42,p=0.001)as well as a positive correlation between NH in the right precuneus and sleep disturbances(r=0.41,p=0.002)in patients with *** MDD with sleep disturbances is associated with abnormal NH in the DMN,which could differentiate pa_s from pa_*** DMN may play a crucial role in the neurobiological mechanisms of MDD with sleep disturbances.

关键词： sleep medial cortex

Natural Products Improve Organ Microcirculation Dysfunction Following Ischemia/Reperfusion-and lipopolysaccharide-Induced Disturbances:Mechanistic and Therapeutic Views

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Engineering 2024年第7期38卷 77-99页

作者： Jingyan Han Quan li Kai Sun Chunshui Pan Jian liu ping huang Juan Feng Yanchen liu Gerald A.Meininger Department of Integration of Chinese and Western Medicine School of Basic Medical SciencesPeking UniversityBeijing 100191China Tasly Microcirculation Research Center Peking University Health Science CenterBeijing 100191China Key Laboratory of Stasis and Phlegm State Administration of Traditional Chinese Medicine of the People’s Republic of ChinaBeijing 100191China Beijing Laboratory of Integrative Microangiopathy Peking University Health Science CenterBeijing 100191China Dalton Cardiovascular Research Center and Department of Medical Pharmacology and Physiology University of MissouriColumbiaMO 65211USA

Microcirculatory disturbances are complex processes caused by many factors,including abnormal vasomotor responses,decreased blood flow velocity,vascular endothelial cell injury,altered leukocyte and endothelial cell interactions,plasma albumin leakage,microvascular hemorrhage,and *** disturbances involve multiple mechanisms and interactions among mechanisms that can include energy metabolism,the mitochondrial respiratory chain,oxidative stress,inflammatory factors,adhesion molecules,the cytoskeleton,vascular endothelial cells,caveolae,cell junctions,the vascular basement membrane,neutrophils,monocytes,and *** clinical practice,aside from drugs that target abnormal vasomotor responses and platelet adhesion,there continues to be a lack of multi-target drugs that can regulate the complex mechanistic links and interactions underlying microcirculatory *** products have demonstrated obvious positive therapeutic effects in treating ischemia/reperfusion(I/R)-and lipopolysaccharide(LPS)-induced microcirculatory *** recent years,numerous research papers on the improvement of microcirculatory function by natural products have been published in international *** 2008 and 2017,the first listed author of this review was invited to publish reviews in the journal of Pharmacology&Therapeutics on the improvement of microcirculatory disturbances and organ injury induced by I/R using Salvia miltiorrhiza ingredients and other natural components of compounded Chinese medicine,*** review systematically summarizes the effects,targets of action,and mechanisms of natural products regarding improving I/R-and LPSinduced microcirculatory disturbances and tissue *** on this summary,scientific proposals are suggested for the discovery of new drugs to improve microcirculatory disturbances in disease.

关键词： Ischemia/reperfusion lipopolysaccharide Natural products Leukocyte activation Hyperpermeability

Time-of-flight resolved stimulated Raman scattering microscopy using counter-propagating ultraslow Bessel light bullets generation

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light(Science & Applications) 2024年第7期13卷 1427-1440页

作者： Shulang lin li Gong Zhiwei huang Optical Bioimaging Laboratory Department of Biomedical EngineeringCollege of Design and EngineeringNational University of SingaporeSingapore 117576Singapore

We present a novel time-of-flight resolved Bessel light bullet-enabled stimulated Raman scattering(B2-SRS)microscopy for deeper tissue 3D chemical imaging with high resolution without a need for mechanical *** accomplish the tasks,we conceive a unique method to enable optical sectioning by generating the counterpropagating pump and Stokes Bessel light bullets in the sample,in which the group velocities of the Bessel light bullets are made ultraslow(e.g.,vg≈0.1c)and tunable by introducing programmable angular dispersions with a spatial light *** theoretically analyze the working principle of the collinear multicolor Bessel light bullet generations and velocity controls with the relative time-of-flight resolved detection for SRS 3D deep tissue *** have also built the B2-SRS imaging system and present the first demonstration of B2-SRS microscopy with Bessel light bullets for 3D chemical imaging in a variety of samples(e.g.,polymer bead phantoms,biological samples such as spring onion tissue and porcine brain)with high *** B2-SRS technique provides a>2-fold improvement in imaging depth in porcine brain tissue compared to conventional SRS *** method of optical sectioning in tissue using counter-propagating ultraslow Bessel light bullets developed in B2-SRS is generic and easy to perform and can be readily extended to other nonlinear optical imaging modalities to advance 3D microscopic imaging in biological and biomedical systems and beyond.

关键词： Bessel resolved propagating

Improvements in properties of NdFeB magnets obtained via magnetron sputtering and thermal diffusion

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Journal of Rare Earths 2024年第9期42卷 1710-1716,I0003页

作者： Jin Tang Weichao huang Dan li School of Electronic Engineering Guangxi University of Science and TechnologyLiuzhou545006China China Rare Earth(Guangxi)Jinyuan Rare Earth New Materials Co. Ltd.Hezhou542603China China Rare Earth Group Co. Ltd.Ganzhou341000China Center of Experimental Teaching for Common Courses Panzhihua UniversityPanzhihua617000China

The grain boundary diffusion process(GBDP) of Dy and DyAl on sintered NdFeB magnets was conducted via magnetron-sputtering deposition of Dy and DyAl films to enhance coercivity(H_(cj)),The magnetic properties,microstructure and anti-corrosion properties of Dy-surface-alloying NdFeB magnets obtained via magnetron sputtering and thermal diffusion were *** H_(cj) of the Dy_(95)Al_(5)-NdFeB magnet increases by 32.68%,while the remanence declines ***,X-ray diffraction and microstructural analysis confirm the formation of Dy-rich shells,the higher-magnetic-anisotropy field of hard(Nd_(x)Dy_(1-x))2(FeAl)_(14)B magnetic phases and an optimised grain boundary structu re,contributing to the H_(cj)enhancement of the *** elemental distribution and diffusion mechanism of the magnets are also ***,the corrosion resistance of the Dy_(95)Al_(5)-NdFeB magnet is substantially improved by enhancing the electrochemical stability and optimising the distribution and morphology of the intergranular *** findings of this study are of substantial importance in the development of low-heavy rare-earth sintered NdFeB magnets.

关键词： Magnetron sputtering NdFeB Rare earths Microstructure Magnetic property Corrosion resistance

Access to High-Molecular-Weight Polyethylenes through High Temperature Ethylene Polymerization Catalysed by Ethylene-Bridged ansa-(3-R-Cyclopentadienyl)(Fluorenyl) Zirconocene Complexes

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Chinese Journal of Polymer Science 2024年第1期42卷 42-51,I0007页

作者： Bo li Haiyan Ma Jiling huang Shanghai Key Laboratory of Functional Materials Chemistry and Laboratory of Organometallic Chemistry School of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

A series of C1-symmetric ethylene-bridged ansa-(3-R-cyclopentadienyl)(fluorenyl) metallocene complexes(Zr: 1-5;Hf: 6) have been synthesized, characterized and investigated as catalyst precursors for the high temperature ethylene polymerization. Using methylaluminoxane(MAO) as the cocatalyst, zirconium complexes 1-5 bearing a bulky substituent on the 3-position of the cyclopendienyl ring showed high catalytic activities up to 1.48×10^(7) g PE·mol_(Zr)^(-1)·h^(-1) toward the polymerization of ethylene and afforded polyethylenes with high molecular weights(1.49×10^(5)-6.31×10^(5) g/mol), meanwhile exhibting great thermal stability at high temperatures up to 120 ℃ together with a long catalytic life time up to 2 h. By adopting low Al/Zr ratios, such as 125, polyethylenes with ultra high molecular weights up to 2.86×106 g/mol were obtained. It is worthy of noting that zirconium complexes 1-4 bearing a substituent with an aryl pendant showed temperature-dependent activities, which increased rapidly with the increase of polymerization temperature, thus weak interaction of the pendent aryl group with the cationic active center is proposed to account for the very low activities displayed at low temperatures. In contrast to zirconocene complexes 1-5, hafnocene complex 6 only displayed very low catalytic activities toward the polymerization of ethylene and afforded polyethylenes with molecular weights ten times smaller than those obtained by zirconocene complexes 1-5. Zirconocene complexes 1-5 were also able to catalyse the polymerization of propylene at high temperatures, but only afforded waxes with low molecular weights.

关键词： ansa-Metallocene Ethylene Propylene Polymerization High temperature

Modeling the Interaction between Vacancies and Grain Boundaries during Ductile Fracture

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Computer Modeling in Engineering & Sciences 2024年第8期140卷 2019-2034页

作者： Mingjian li ping Yang Pengyang Zhao Department of Engineering Mechanics School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China

The experimental results in previous studies have indicated that during the ductile fracture of pure metals,vacancies aggregate and form voids at grain ***,the physical mechanism underlying this phenomenon remains not fully *** study derives the equilibrium distribution of vacancies analytically by following thermodynamics and the micromechanics of crystal *** derivation suggests that vacancies cluster in regions under hydrostatic compression to minimize the elastic strain ***,a finite element model is developed for examining more general scenarios of interaction between vacancies and grain *** model is first verified and validated through comparison with some available analytical solutions,demonstrating consistency between finite element simulation results and analytical solutions within a specified numerical accuracy.A systematic numerical study is then conducted to investigate the mechanism that might govern the micromechanical interaction between grain boundaries and the profuse vacancies typically generated during plastic *** simulation results indicate that the reduction in total elastic strain energy can indeed drive vacancies toward grain boundaries,potentially facilitating void nucleation in ductile fracture.

关键词： Ductile fracture vacancy grain boundary micromechanical finite element method