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Design and motion analysis of reconfigurable wheel-legged mobile robot

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Defence Technology（防务技术） 2022年第6期18卷 1023-1040页

作者： Shuo Zhang Jian-tao Yao Ying-bin Wang Zi-sheng liu Yun-dou Xu yong-sheng Zhao School of Mechanical Engineering Yanshan UniversityHebeiChina

An adaptive wheel-legged shape reconfigurable mobile robot,based on a scissor-like mechanism,is proposed for an obstacle detecting and surmounting robot,moving on complex *** robot can dynamically adjust its own shape,according to the environment,realizing a transformation of wheel shape into leg shape and vice *** wheel-legged mechanism has one degree of freedom,which means that only the relative motion of the inner and outer discs is needed to achieve the transformation of the shape into a wheel or a ***,the force analysis of the conversion process of the wheel-legged mechanism is carried out,while the relationship between the driving torque and the friction factor in the non-conversion trigger stage and in the conversion trigger stage is *** results showed that the shape conversion can be better realized by increasing the friction factor of the trigger ***,the kinematics analysis of the robot,including climbing the obstacles,stairs and gully,is carried *** motion of the spokes tip is obtained,in order to derive the folding ratio and the surmountable obstacle height of the wheel-legged *** parameters of the wheel-legged structure are optimized,to obtain better stability and obstacle climbing ***,a dynamic simulation model is established by ADAMS,to verify the obstacle climbing performance and gait rationality of the robot,in addition to a prototype *** results showed that the surmountable obstacle height of the robot is about3.05 times the spoke *** robot has the stability of a traditional wheel mechanism and the obstacle surmount performance of a leg mechanism,making it more suitable for field reconnaissance and exploration missions.

关键词： Mobile robots Scissor mechanism Kinematics ADAMS simulation Obstacle surmounting

Thermal sensation and percentage of dissatisfied in thermal environments with positive and negative vertical air temperature differences

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Energy and Built Environment 2023年第6期4卷 629-638页

作者： Yuxin Wu sheng Zhang Hong liu yong Cheng School of Civil Engineering and Architecture Zhejiang Sci-Tech UniversityHangzhouZhejiang 310018China Joint International Research Laboratory of Green Buildings and Built Environments(Ministry of Education) Chongqing UniversityChongqing 400045China School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710049China School of Civil Engineering Chongqing UniversityChongqing 400045China

Considering the percentage of dissatisfied due to local thermal sensation(PD LTSV),a vertical air temperature difference(ΔT_(d))threshold of about 3°C was recommended in ***,some novel air distribution methods might create large positive(which means the head warmer than the feet,vice versa)or negativeΔT_(d),with no suitable proved criteria to be *** this study,sixteen subjects were seated in a climatic box placed in a climate chamber to evaluate thermal sensation and percentage of dissatisfied with negative and positiveΔT_(d) in different whole-body thermal *** temperatures were controlled independently at the upper and lower body parts,with 13 different air temperature sets combined with 22°C,25°C,28°C,and 31°C(i.e.-9°C≤ΔT_(d)≤9°C).Results showed that subjects were more thermally sensitive at the upper body and with positiveΔT_(d) than at the lower body or with negativeΔT_(d).The 80%acceptableΔT_(d) range is about-8 to 7°C in overall neutral(TSV=0),-7°C to 6°C in slightly cool(TSV=-0.5)conditions,which is wider than-3 to 3°C in slightly warm conditions(TSV=+0.5).By considering the factors of both TSV andΔT_(d),a new overall percentage of dissatisfied index(OPD P)was *** studies show that the new OPD P index is more precise and suitable for the evaluations of different air distributions to predict overall percentage of dissatisfied in thermal environments with vertical air temperature difference.

关键词： Vertical air temperature difference Thermal sensation Thermal comfort Percentage of dissatisfied Air distribution

Development and simulation of a gridded thermionic cathode electron gun for a high-energy photon source

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Nuclear Science and Techniques 2023年第3期34卷 73-81页

作者： sheng-Chang Wang Da-yong He Cai Meng Jing-Yi Li Zu-sheng Zhou Jin-Dong liu Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

A gridded thermionic cathode electron gun was developed for the linear accelerator of the High Energy Photon Source(HEPS).An electron gun should provide a large maximum bunch charge with a wide adjustable *** satisfy these requirements,the shape of the electrode was optimized using a multi-objective genetic algorithm.A large bunch charge with an adjustable range was achieved using the grid-limited gun,the flow of which was analyzed using 3-D *** electron gun has been manufactured and tested,and the measured data of the grid-limited current and simulation results are compared and discussed in this study.

关键词： Electron gun Multi-objective genetic algorithm Grid CST

Metal-organic framework microlasers

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Science Bulletin 2017年第1期62卷 3-4页

作者： Yuan liu Haiyun Dong Fengqin Hu yong sheng Zhao College of Chemistry Beijing Normal University Key Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences

The discovery and continued development of the lasers have led to a revolution in both fundamental researches and optoelectronic ***,micro/nanolasers that can generate intense coherent light signals at(sub)wavelength scale have become a research focus due to their potential applications in a variety of fields ranging from chemical and biological sensing to integrated optoelectronic circuitry[1,2].Organic materials are a kind of excel-

关键词：纳米激光器金属有机骨架光电集成电路有机材料微型激光器 Excel 基础研究持续发展

Microstructure and electrolysis behavior of self-healing Cu-Ni-Fe composite inert anodes for aluminum electrowinning

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International Journal of Minerals,Metallurgy and Materials 2018年第10期25卷 1208-1216页

作者： Ying liu yong-an Zhang Wei Wang Dong-sheng Li Jun-yi Ma State Key Laboratory of Non-Ferrous Metals and Processes General Research Institute for Nonferrous MetalsBeijing 100088China Zhengzhou Non-ferrous Metals Research Institute Co.Ltd.of CHALCO Zhengzhou 450041China

The microstructure evolution and electrolysis behavior of(Cu_(52)Ni_(30)Fe_(18))–x Ni Fe_2O_4(x=40wt%,50wt%,60wt%,and 70wt%)composite inert anodes for aluminum electrowinning were *** Fe_2O_4 was synthesized by solid-state reaction at 950°*** dense anode blocks were prepared by ball-milling followed by sintering under a N_2 *** phase evolution of the anodes after sintering was determined by scanning electron microscopy and energy-dispersive X-ray *** results indicate that a substitution reaction between Fe in the alloy phase and Ni in the oxide phase occurs during the sintering *** samples were also examined as inert anodes for aluminum electrowinning in the low-temperature KF–NaF–AlF_3 molten electrolyte for 24 *** cell voltage during electrolysis and the corrosion scale on the anodes were *** results confirm that the scale has a self-repairing function because of the synergistic reaction between the alloy phase with Fe added and the oxide *** estimated wear rate of the(Cu_(52)Ni_(30)Fe_(18))–50Ni Fe_2O_4 composite anode is 2.02 cm·a^(-1).

关键词： aluminum electrolysis inert anode composites aluminum electrowinning corrosion

Alterations of Alternative Splicing Patterns of Ser/Arg-Rich (SR) Genes in Response to Hormones and Stresses Treatments in Different Ecotypes of Rice (Oryza sativa)

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Journal of Integrative Agriculture 2013年第5期12卷 737-748页

作者： ZHANG Peng DENG Heng XIAO Fang-ming liu yong-sheng Key Laboratory for Bio-Resource and Eco-Environment Ministry of Education/State Key Laboratory of Hydraulics and Mountain River Engineering/College of Life Science Sichuan University Neijiang Hybrid Rice Research and Development Center Department of Plant Soil and Entomological Sciences University of Idaho School of Biotechnology and Food Engineering Hefei University of Technology

Ser/Arg-rich （SR） genes encode proteins that play pivotal roles in both constitutive and alternative splicing of pre-mRNA. However, not much effort has been made to investigate the alternative splicing of their own pre-mRNA. In this study, we conducted comprehensive analyses of pre-mRNA splicing for 22 SR genes in three rice （Oryza sativa L.） ecotypes indica, japonica andjavanica. Using different ecotypes we characterized the variations in expression and splicing patterns of rice SR genes in different tissues and at different developmental stages. In addition, we compared the divergence in expression and splicing patterns of SR genes from seedlings of different rice ecotypes in response to hormones application and environmental stresses. Our results revealed the complexity of alternative splicing of SR genes in rice. The splicing varies in different tissues, in different ecotypes, in response to stresses and hormones. Thus, our study suggested that SR genes were subjected to sophisticated alternative splicing although their encoding proteins were involved in the splicing process.

关键词： SR protein alternative splicing stress rice

Changes in global land surface frozen ground and freeze-thaw processes during 1950-2020 based on ERA5-Land data

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Advances in Climate Change Research 2024年第2期15卷 265-274页

作者： yong YANG Ren-sheng CHEN yong-Jian DING Hong-Yuan LI Zhang-Wen liu Qilian Alpine Ecology and Hydrology Research Station Key Laboratory of Ecological Safety and Sustainable Development in Arid LandsNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73000China Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection College of Resources and EnvironmentLinyi UniversityLinyi 276000China

Frozen ground(FG)plays an important role in global and regional climates and environments through changes in land freeze-thaw processes,which have been conducted mainly in different ***,the changes in land surface freeze-thaw processes under climate change on a global scale are still *** on ERA5-Land hourly land skin temperature data,this study evaluated changes in the global FG area,global land surface first freeze date(FFD),last freeze date(LFD)and frost-free period(FFP)from 1950 to *** results show that the current FG areas(1991-2020 mean)in the Northern Hemisphere(NH),Southern Hemisphere(SH),and globe are 68.50×10^(6),9.03×10^(6),and 77.53×10^(6)km^(2),which account for 72.4%,26.8%,and 60.4%of the exposed land(excluding glaciers,ice sheets,and water bodies)in the NH,SH and the globe,respectively;further,relative to 1951-1980,the FG area decreased by 1.9%,8.8%,and 2.8%,*** FG at lower latitudes degrades to intermittently FG,and intermittently FG degrades to non-frozen ground,which caused the global FG boundary to retreat to higher latitudes from 1950 to *** annual FG areas in the NH,SH,and globe all show significant decreasing trends(p<0.05)from 1950 to 2020 at-0.32×10^(6),-0.22×10^(6),and-0.54×10^(6)km^(2)per decade,*** FFP prolongation in the NH is mainly influenced by LFD advance,while in the SH it is mainly controlled by FFD *** prolongation trend of FFP in the NH(1.34 d per decade)is larger than that in the SH(1.15 d per decade).

关键词： Frozen ground Freeze-thaw processes Frost-free period First freeze date Global warming

A Signal Based “W” Structural Elements for Multi-scale Mathematical Morphology Analysis and Application to Fault Diagnosis of Rolling Bearings of Wind Turbines

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International Journal of Automation and computing 2021年第6期18卷 993-1006页

作者： Qiang Li yong-sheng Qi Xue-Jin Gao yong-Ting Li Li-Qiang liu Institute of Electric Power Inner Mongolia University of TechnologyHohhot 010080China Inner Mongolia Key Laboratory of Electrical and Mechanical Control Hohhot 010051China Faculty of Information Beijing University of TechnologyBeijing 100124China

Working conditions of rolling bearings of wind turbine generators are complicated, and their vibration signals often show non-linear and non-stationary characteristics. In order to improve the efficiency of feature extraction of wind turbine rolling bearings and to strengthen the feature information, a new structural element and an adaptive algorithm based on the peak energy are proposed,which are combined with spectral correlation analysis to form a fault diagnosis algorithm for wind turbine rolling bearings. The proposed method firstly addresses the problem of impulsive signal omissions that are prone to occur in the process of fault feature extraction of traditional structural elements and proposes a "W" structural element to capture more characteristic information. Then, the proposed method selects the scale of multi-scale mathematical morphology, aiming at the problem of multi-scale mathematical morphology scale selection and structural element expansion law. An adaptive algorithm based on peak energy is proposed to carry out morphological scale selection and structural element expansion by improving the computing efficiency and enhancing the feature extraction ***, the proposed method performs spectral correlation analysis in the frequency domain for an unknown signal of the extracted feature and identifies the fault based on the correlation coefficient. The method is verified by numerical examples using experimental rig bearing data and actual wind field acquisition data and compared with traditional triangular and flat structural elements. The experimental results show that the new structural elements can more effectively extract the pulses in the signal and reduce noise interference,and the fault-diagnosis algorithm can accurately identify the fault category and improve the reliability of the results.

关键词： Fault diagnosis structural element multi-scale mathematical morphology rolling bearing correlation analysis

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微通道板(MCP)的真空出气性能研究

真空 2016年第5期53卷 4-6页

作者：郭迪舟马永胜刘佰奇刘术林宋洪中国科学院高能物理研究所北京100049

本文介绍了采用动态法测量铅硅酸盐玻璃微通道板(MCP)未烘烤和高温烘烤后的出气特性,通过整理实验数据得出MCP的出气速率曲线。得出未经烘烤处理的MCP常温出气率最大为3.99×10-7Pa·L/s·cm^2左右。经过430℃24小时烘烤冷却后,最大为1... 详细信息

本文介绍了采用动态法测量铅硅酸盐玻璃微通道板(MCP)未烘烤和高温烘烤后的出气特性,通过整理实验数据得出MCP的出气速率曲线。得出未经烘烤处理的MCP常温出气率最大为3.99×10-7Pa·L/s·cm^2左右。经过430℃24小时烘烤冷却后,最大为1.86×10^(-8)Pa·l/s·cm^2左右。从实验数据看出其有一定的吸气效果。对残余气体谱图进行分析,发现其易受碳氢化合物或其含氧衍生物污染,并且通过高温烘烤也难以清除干净。

关键词：微通道板表面放气率吸气性能残余气体