检索结果-南通市图书馆

Bionic lightweight design of limb leg units for hydraulic quadruped robots by additive manufacturing and topology optimization

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Bio-Design and Manufacturing 2024年第1期7卷 1-13页

作者： Huaizhi Zong Junhui zhang {1. Jiang Kun zhang Jun Shen Zhenyu Lu Ke wang Yanli wang Bing Xu The State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310058China Unmanned Vehicle Research and Development Center China North Vehicle Research InstituteBeijing 100072China School of Mechatronic Engineering Nanchang UniversityNanchang 330031China Auclean High-Tech Ltd. Wuxi 214108China

Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped *** various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large *** the most critical movement unit of a quadruped robot,the limb leg unit(LLU)directly affects movement speed and reliability,and requires a compact and lightweight *** by the dexterous skeleton–muscle systems of cheetahs and humans,this paper proposes a highly integrated bionic actuator system for a better dynamic performance of an *** propose that a cylinder barrel with multiple element interfaces and internal smooth channels is realized using metal additive manufacturing,and hybrid lattice structures are introduced into the lightweight design of the piston *** addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the *** mechanical properties of the actuator system are verified by numerical simulation and experiments,and the power density of the actuators is far greater than that of cheetah *** mass of the optimized LLU is reduced by 2..5%,and the optimized LLU shows better response time performance when given a step signal,and presents a good trajectory tracking ability with the increase in motion frequency.

关键词： Additive manufacturing Bionic lightweight design Limb leg unit Quadruped robot Trajectory tracking

Zircon SHRIMP U-Pb geochronology and petrogenesis of the plagiogranites from the Lagkor Lake ophiolite,Gerze,Tibet,china

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 2007年第5期52卷 651-659页

作者： zhang YuXiu1,2. zhang KaiJun1,3, LI Bing1,2. {2. Yang1,2. WEI QingGuo1,2.& TANG XianChun1,2.1 Key Laboratory of Marginal Sea Geology, Guangzhou institute of Geochemistry, chinese academy of sciences, Guangzhou 510640, china 2.Graduate University, chinese academy of sciences, beijing 100039, china 3 Department of Earth sciences, Nanjing University, Nanjing 2.0093, china Key Laboratory of Marginal Sea Geology Guangzhou Institute of GeochemistryChinese Academy of Sciences Guangzhou 510640 China

地关系与 petrographical 一起， petrological ，和 geochemicalcharacteristics ，和锆石人口，显示从在 Bangong-Nujiang 缝术地区的 Lagkor Lakeophiolite 的 plagiogranites (～ Gerze 县的 2. km 南方，中央西藏，中国)，由在海洋的外壳的运输期间的可锻的砍源于含水的斑粝岩的 anatexis 。因此，这种 plagiogranite 比传播海洋的外壳晚对或很少同时代。锆石虾 1.6 ±使 2.5 妈变老因为 plagiogranites 显示海洋的盆在中间的侏罗记在 Bangong-Nujiang 地区的西方的部分存在。

关键词：西藏改则县拉果错湖泊蛇绿岩斜长花岗岩锆SHRIMP U-Pb地质年代岩石成因

Coupling effect of cement-stabilization and biopolymer-modification on the mechanical behavior of dredged sediment

在线全文

学校读者我要写书评

暂无评论

Journal of Rock mechanics and Geotechnical Engineering 2024年第8期16卷 3284-3298页

作者： lei Lang Jiangshan Li Xiao Huang Ping {1. Wei {2. State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China Hubei Provincial Key Laboratory of Contaminated Sludge and Soil Science and Engineering Wuhan430071China University of chinese academy of sciences Beijing100049China

Nowadays,biopolymer stabilization as a promising eco-friendly approach in soft ground improvement has attracted wide ***,the feasibility of using biopolymer as a green additive of cementstabilized dredged sediment(CDS)with high water content is still *** this study,guar gum(GG)and xanthan gum(XG)were adopted as typical biopolymers,and a series of unconfined compressive strength(UCS),splitting tensile strength(STS)and scanning electron microscopy(SEM)tests were performed to evaluate the mechanical and microstructural properties of XG-and GG-modified CDSs considering several factors including biopolymer modification,binderesoil ratio and wateresolid ***,the micro-mechanisms revealing the evolutions of mechanical properties of biopolymermodified CDS were *** results indicate that the addition of XG can effectively improve the strength of CDS,while the GG has a side *** XG content of 9%was recommended,which can improve the 7 d-and 2. d-UCSs by 1.6%and 51.8%,together with the 7 d-and 2. d-STSs by 1.8.3%and 42.2.,*** the binderesoil ratio or decreasing the wateresolid ratio significantly improved the strength gaining but aggravated the brittleness characteristics of *** XG to CDS contributed to the formation of microstructure with more compactness and higher cementation degrees of ordinary Portland cement(OPC)-XG-stabilized DS(CXDS).The micro-mechanism models revealing the interactions of multiple media including OPC cementation,biopolymer film bonding and bridging effects inside CXDS were *** key findings confirm the feasibility of XG modification as a green and high-efficiency mean for improving the mechanical properties of CDS.

关键词： Dredged sediment(DS) Stabilization Biopolymer modification Mechanical properties Micro-mechanism

Electronic structure and magnetic properties of metastable SmCo_(7) compound

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science china(Physics,{1. & Astronomy) 2005年第3期48卷 325-335页

作者： zhang Changwen 1 , LI Hua 1 , DONG Jianmin 1 , wang Yongjuan 1 , PAN Fengchun 1 , zhang Jian 1 , GUO Yongquan 2.& LI Wei 2.1. School of Physics and Microelectronics, Shandong University, Jinan 2.0100, china 2. institute of Functional Materials, Central Iron and Steel Research institute, beijing 100081, china 1. School of Physics and Microelectronics Shandong University 250100 Jinan China 2. {1. of Functional Materials Central Iron and Steel Research Institutes 100081 Beijing China

The electronic density of states, spin-splittings and atomic magnetic moments of SmCo 7 compound have been studied using spin-polarized MS-Xα method. The results show that a few of electrons are transferred to Sm(5d 0 ) orbital because of orbital hybridization between Sm and Co atoms in the compound. The exchange interactions between 3d and 5d electrons lead to the magnetic coupling between Sm and Co, and therefore, result in the long-range ferromagnetic order inside the SmCo 7 compound. There are negative exchange couplings occurring at some levels, which weakens the strength of average coupling around Co lattice. So, the Curie temperature and Co-moment of SmCo 7 decrease distinctly compared with pure Co. Compared with SmCo 5 compound, the disordered substitution of Co-Co “dumbbell-atom” pairs for Sm changes the local environment of Co lattice, which makes the 2. site bear negative magnetic moment. The strength of hybridization near Fermi level weakens and the free energy of the compound increases obviously. Thus, SmCo 7 is a metastable compound at room temperature. Considering the localization of 4f electrons and a few of 5d electrons arising from the orbital hybridization, the magnetic moment of Sm atom will be 1.61. B in SmCo 7 compound, which is in agreement with the experimental values of Sm 3+ ion- moment and Sm atom-moment in metals.

关键词： electronic structure, spin polarization, atomic magnetic moment, exchange coupling, Curie temperature.

Primary scientific results of Chang'E-1.lunar mission

在线全文

学校读者我要写书评

暂无评论

Science china Earth {1. 2010年第11期53卷 1565-1581页

作者： OUYANG ZiYuan1,2, LI ChunLai1, ZOU YongLiao1, zhang HongBo1, Lü Chang1, LIU JianZhong1, LIU JianJun1, ZUO Wei1, SU Yan1, WEN WeiBin1, BIAN Wei1, ZHAO BaoChang3, wang JianYu4, YANG JianFeng3, CHANG Jin5, wang HuanYu6, zhang XiaoHui7, wang ShiJin7, wang Min1, REN Xin1, MU LingLi1, KONG DeQing1, wang XiaoQian1, wang Fang1, GENG liang1, zhang ZhouBin1, ZHENG lei1, ZHU XinYing1, ZHENG YongChun1, LI JunDuo1, ZOU XiaoDuan1, XU Chun1, SHI ShuoBiao1, GAO YiFei1 & GAO GuanNan1 1 National Astronomical Observatories, chinese academy of sciences, beijing 100012.{2. 2 institute of Geochemistry, chinese academy of sciences, Guiyang 550002.{2. 3 Xi’an institute of Optics and Precision mechanics, chinese academy of sciences, Xi’an 710119, china 4 Shanghai institute of Technical Physics, chinese academy of sciences, Shanghai 200083, china 5 Purple Mountain Observatory, chinese academy of sciences, Nanjing 210008, china 6 institute of High Energy Physics, chinese academy of sciences, beijing 100049, china 7 Center for Space Science and Applied Research, chinese academy of sciences, beijing 100190, china 1. National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China2. Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China3. Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an 710119 China4. Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai 200083 China5. Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China6. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China7. Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China

The strategic plan for the development of the unmanned chinese Lunar Exploration Program is characterized by three distinct stages: "orbiting around", "landing on" and "returning from" the Moon. The first chinese lunar probe, Chang'E-1. which was successfully launched on October 2.th, 2.07 at Xichang Satellite Launch Center, and guided to crash on the Moon on March 1.t, 2.09, at 52.36°E, 1.50°S, in the north of Mare Fecunditatis, is the first step towards the "orbiting around" stage. The Chang'E-1.mission lasted 495 days, exceeding the expected life-span by about four months. A total of 1.37 TB raw data was received from Chang'E-1. It was then processed into 4 TB scientific data products at various levels. Many scientific results have been obtained by analyzing these data, including especially the "global lunar image from the first chinese lunar explora- tion mission". All scientific goals of Chang'E-1.have been achieved. It provides much useful materials for further advances of lunar sciences and planetary chemistry. Meanwhile, these results will serve as a firm basis for future chinese lunar missions.

关键词： lunar orbiter Chang’E-1 scientific data results

Research progress on Drosophila visual cognition in china

在线全文

学校读者我要写书评

暂无评论

Science china(Life {1.) 2010年第3期53卷 374-384页

作者： GUO AiKe1,2.zhang Ke1,PENG YueQin1 & XI wang1 1 {2. of Neuroscience,State Key Laboratory of Neuroscience,Shanghai {2.s for Biological sciences,chinese academy of sciences,Shanghai 2.0031,china 2.State Key Laboratory of Brain and Cognitive Science,{2. of Biophysics,chinese academy of sciences,beijing 100101,china 1. institute of Neuroscience State Key Laboratory of Neuroscience Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200031 China2. State Key Laboratory of Brain and Cognitive Science Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China

Visual cognition,as one of the fundamental aspects of cognitive neuroscience,is generally associated with high-order brain functions in animals and ***,as a model organism,shares certain features of visual cognition in common with mammals at the genetic,molecular,cellular,and even higher behavioral *** learning and memory to decision making,Drosophila covers a broad spectrum of higher cognitive behaviors beyond what we had *** with powerful tools of genetic manipulation in Drosophila,an increasing number of studies have been conducted in order to elucidate the neural circuit mechanisms underlying these cognitive behaviors from a genes-brain-behavior *** goal of this review is to integrate the most important studies on visual cognition in Drosophila carried out in china's Mainland during the last decade into a body of knowledge encompassing both the basic neural operations and circuitry of higher brain function in ***,we consider a series of the higher cognitive behaviors beyond learning and memory,such as visual pattern recognition,feature and context generalization,different feature memory traces,salience-based decision,attention-like behavior,and cross-modal leaning and *** discuss the possible general gain-gating mechanism implementing by dopamine-mushroom body circuit in fly's visual *** hope that our brief review on this aspect will inspire further study on visual cognition in flies,or even beyond.

关键词： Visual invariance recognition visual memory traces feature and context generalization selective attention cross-modality memory integration salience-based decision making

Parallel Implementation of the CCSDS Turbo Decoder on GPU

在线全文

学校读者我要写书评

暂无评论

china Communications 2024年第10期21卷 70-77页

作者： Liu Zhanxian Liu Rongke zhang Haijun {1. Ning Sun {2. {1. Jianquan School of Computer&Communication Engineering University of Science and Technology BeijingBeijing 100083China School of Electronic and Information Engineering Beihang UniversityBeijing 100191China beijing Engineering and Technology Research Center for Convergence Networks and Ubiquitous Services Institute of Artificial IntelligenceUniversity of Science and Technology BeijingBeijing 100083China School of Information Engineering Zhengzhou UniversityZhengzhou 450001China School of Automation and Electrical Engineering University of Science and Technology BeijingBeijing 100083China

This paper presents a software turbo decoder on graphics processing units(GPU).Unlike previous works,the proposed decoding architecture for turbo codes mainly focuses on the Consultative Committee for Space Data Systems(CCSDS)***,the information frame lengths of the CCSDS turbo codes are not suitable for flexible sub-frame parallelism *** mitigate this issue,we propose a padding method that inserts several bits before the information frame *** obtain low-latency performance and high resource utilization,two-level intra-frame parallelisms and an efficient data structure are *** presented Max-Log-Map decoder can be adopted to decode the Long Term Evolution(LTE)turbo codes with only small *** proposed CCSDS turbo decoder at 1. iterations on NVIDIA RTX3070 achieves about 1.0 Mbps and 50Mbps throughputs for the code rates 1.6 and 1.2.respectively.

关键词： CCSDS CUDA GPU parallel decoding turbo codes

Dynamic characteristics of nonlinear vibration isolator for gas turbine

在线全文

学校读者我要写书评

暂无评论

International Journal of Mechanical System Dynamics 2024年第3期4卷 374-383页

作者： Teng wang Linhan Feng {1. {2. Chunhui {2. Yue Wu Naval Research institute BeijingChina

In this study,a theoretical model of the vibration isolation system of the gas turbine is developed and numerically solved.A simplified finite element(FE)model was also established to determine the response under the shock *** results of the FE model are used to verify the effectiveness of the theoretical model and the numerical *** influence of isolator stiffness,vibration isolator damping,and vibration isolator nonlinear stiffness coefficient on the shock response of the vibration isolation system is studied using the controlled-variable *** parameters(stiffness,damping,and nonlinear coefficient)enter into the shock resistance design of gas turbine vibration isolators.

关键词： gas turbine vibration isolator theoretical model damping dynamic characteristics

^(1.7)Cs Redistribution in Thin Stony Soil of a Carbonate Rock Slope in Southwest china

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2011年第1期21卷 37-45页

作者： LI Hao zhang Xin-Bao {1. Kc-Lin WEN An-Bang institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu 610041 (China) Graduate University Chinese Academy of Sciences Beijing 100049 (China) State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 (China) institute of Subtropical Agriculture Chinese Academy of Sciences Changsha 410125 (China)

The fallout radionuclide cesium-1.7(1.7 Cs) has been widely employed as a tracer for assessment of soil loss from thick uniform soils;however,few studies have been conducted on thin stony soils on slopes underlain by carbonate rocks which are widely distributed in karst *** derived from 1.7 Cs measurement of soil samples collected along a carbonate rock slope with thin stony soil where neither soil erosion nor deposition occurred was used to investigate the characteristics of 1.7 Cs redistribution in a karst area of Southwest *** results indicated that the 1.7 Cs inventories of the surface soil on the slope studied were much lower than that of the local 1.7 Cs reference inventory and the 1.7 Cs activities were much higher than those on slopes with thick uniform *** spatial distribution of 1.7 Cs inventories was characterized by considerable *** high 1.7 Cs depletion in the stony soil of the slope studied was mainly because a considerable proportion of the fallout input of 1.7 Cs could be lost with runoff and the dissolution of carbonate particles in the soil promoted the loss of 1.7 *** demonstrated that the rates of soil loss could not be estimated from the degree of depletion of the 1.7 Cs inventory relative to the local reference inventory for the thin stony soil of the rocky slope underlain by carbonate rocks in the study area in the way that has been widely used in areas with thick uniform soils.

关键词： carbonate dissolution, ^1.7Cs fallout, ^1.7Cs inventory karst area runoff