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Snake robots play an important role in social services and military needs

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The Innovation 2022年第6期3卷 25-26页

作者： Dongfang Li Binxin Zhang Yang Xiu Hongbin Deng Miaomiao Zhang wei Tong Rob Law Guangyu zhu Edmond q.wu Limin zhu School of Electrical Engineering and Automation Fuzhou UniversityFujian 350108China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China Department of Automation Shanghai JiaoTong UniversityShanghai 200240China School of Automation Nanjing University of Science and TechnologyNanjing 210094China Asia-Pacific Academy of Economics and Management Faculty of Business AdministrationUniversity of MacaoMacao 999078China School of Traffic and Transportation Beijing JiaoTong UniversityBeijing 100044China

Intelligent robotic systems have gradually penetrated into the fields of social services and military reconnaissance with the rapid economic *** robots,as multi-redundant bionic robots,play an indispensable and important role in public life and military needs.1 These robots have been widely favored and highly regarded by the academia and industry because of 1)their small size and flexibility,thereby easily entering small spaces for work,2)their ability to carry a variety of equipment for disaster rescue and military reconnaissance,and 3)their variety of movement modes,which can adapt to various complex terrain environments.

关键词： Snake services military

IN SITU OBSERVATION OF GROwTH BEHAVIOR AND MORPHOLOGY OF DELTA-FERRITE AS FUNCTION OF SOLIDIFICATION RATE IN AN AISI304 STAINLESS STEEL

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Acta Metallurgica Sinica(English Letters) 2006年第6期19卷 441-448页

作者： G.F.Liang C.q.wan J.C.wu G.M.zhu Y.Yu Y.Fang Advanced Technology Institute Technology Center of BaosteelShanghai 201900China Department of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200030China

It was presented the in situ observation of growth behavior and morphology of delta-ferrite as a function of solidification rate in an AISI304 stainless steel. The specimens have been solidified and observed using confocal scanning laser microscopy (CSLM). The δ-phase always appears like cells on the sample surface when critical supercooling occurs, during which the L→δ transformation starts. The solid-liquid (S-L) interface is found to be finger shaped and has no faceted shape. γ phase appears among δ grains due to partitioning of Ni into the melt during solidification, when solidification rate is higher. The mergence of observed δ cells is possible for the steel sample cooled at 7.5℃/min. The formation of dendrites can be observed on the free surface of the steel sample cooled at 150℃/min. The size of solidified delta grains decreases from 120 to 20-80μm, and the volume fraction of solidified austenite increases with increase in solidification rate from 7.5 to 150℃/min. The relation between the tip radius of δ cell and its growth rate is deduced, and the results agree with the experimental values.

关键词： stainless steel confocal scanning laser microscopy δ-ferrite in situ observation solidification

MICROSTRUCTURE FORMATION AND MECHANICAL PROPERTY INVOLVING ICOSAHEDRAL qUASICRYSTAL PHASE OF Y RICH Mg-Zn-Y qUASICRYSTAL ALLOY

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Acta Metallurgica Sinica(English Letters) 2007年第6期20卷 429-433页

作者： D.q. wan G.C. Yang M. zhu State Key Laboratory of Solidification Processing NorthwesternPloytechnical University Xi＇an 710072 China

The microstructure formation and mechanical property involving icosahedral quasicrystal （I-phase） in the Y-rich Mg-Zn-Y alloy have been studied. The equilibrium formation of I-phase from the Y-rich Mg-Zn-Y melt is through a peritectic reaction between the Y-rich melt and the primary w-phase, which is discussed in detail. The independent nucleation and coupling growth mechanism between the w-phase and the I-phase, from the melt, are revealed, which is significant for understanding the peritectic reaction process involving icosahedral quasicrystal in the Mg-Zn-Y alloy. The mechanism of the quasicrystal phase strengthened magnesium alloys is also discussed here.

关键词： Mg-Zn-Y icosahedral quasicrystal peritectic reaction mechanical property

Microstructural softening induced adiabatic shear banding in Ti-23Nb-0.7Ta-2Zr-O gum metal

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Journal of Materials Science & Technology 2020年第19期54卷 31-39页

作者： Silu Liu Y.Z.Guo Z.L.Pan X.Z.Liao E.J.Lavernia Y.T.zhu q,M,wei Yonghao Zhao Nano and Heterogeneous Materials Center School of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China Department of Mechanical Engineering University of North Carolina at CharlotteNC 28223-0001USA School of Aerospace Mechanical and Mechatronic EngineeringThe University of SydneyNSW 2006Australia Department of Materials Science and Engineering University of Californi1IrvineCA 92697USA Department of Materials Science and Engineering North Carolina State UniversityNC 27695USA

Ti-23Nb-0.7Ta-2Zr-O gum metal(GM)is an attractive candidate material for applications that require superior mechanical *** our earlier investigation of the GM[1],geometrical softening and the generation of adiabatic shear bands(ASBs)were proposed as primary reasons for the documented anisotropic impact *** the present study,electron backscattered diffraction(EBSD)analysis reveals two different deformed microstructures,i.e.,deformed ultrafine grains(UFGs)and dynamically recrystallized UFGs,formed in the ASBs of GM samples processed by extrusion equal channel angular pressing(ECAP),*** calculation of temperature rise during dynamic compression suggests that the above microstructure differences in the ASBs was originated from their different maximum ASB temperatures(608 K for extruded GM and 1159 K for ECAP-processed GM).Moreover,our calculation on the temperature at the onset of ASBs indicates that microstructural softening is the primary cause for the development of ASBs in both extruded GM(321 K)and ECAP-processed GM(331 K).

关键词： Gum metal Split hopkinson bar Adiabatic shear band Microstructures

Fuzzy Sliding Mode Control for Discrete Nonlinear Systems

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计算技术与自动化 2003年第Z1期22卷 311-316页

作者： F.qiao.q.M.zhu Faculty of CEMS University of the West of England Frenchay CampusColdharbour LaneBristol BS16 1QYUK

Sliding mode control is introduced into classical model free fuzzy logic control for discrete time nonlinear systems with uncertainty to the design of a novel fuzzy sliding mode control to meet the requirement of necessary and sufficient reaching conditions of sliding mode control. The simulation results show that the proposed controller outperforms the original fuzzy sliding mode controller and the classical fuzzy logic controller in stability, convergence and robustness.

关键词： Fuzzy logic sliding mode control nonlinear systems discrete time control

^(199)Sn AND ^(57)Fe MOSSBAUER SPECTROSCOPIC STUDY OF THE MECHANICALLY ALLOYED Fe-Sn ALLOYS

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Acta Metallurgica Sinica(English Letters) 1998年第5期11卷 335-341页

作者： Y.Z.Yang Y.L.zhu q.S.Li X.M.Ma Y.D.Dong Y.Z.Chuang Guangdong Univ of Technology Guangzhou China

Nanocrystalline supersaturated solid solutions (Sa in Fe) with Sn content less than 50 at. %,and FeSn2 and Fe1.3Sn intermetallic compounds have been prepared by mechanical alloying of Fe and Sn mixture powders with composition of Fe1-xSnx (x≤0.5).The atomic alloying the formation and microstructure, especially the coordination environments, of the resultant alloys have been studied by X-ray diffraction, 57Fe and 119Sn Mossbauer Spectroscopy and diffrrential scanning calorimetry. The Fe and Sn coordination environments and the composition dependence of the hyperfine parameters on the Fe and Sn content have been fully discussed with respect to the solid dissolution alloying, grain refinement, and distortion caused or induced by mechanical alloying.

关键词： mechanical alloying Mossbauer effect nanocrystalline Fe-Sn alloy

Influence of Re on the Properties of a NiCoCrAlY Coating Alloy

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Journal of Materials Science & Technology 2011年第5期27卷 408-414页

作者： J.J. Liang H. we Y.L. zhu X.F. Sun Z.q. Hu M.S. Dargusch X.D. Yao Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Graduate School of Chinese Academy of Sciences Beijing 100039 China School of Materials & Mining Engineering The University of Queensland QLD 4072 Australia

MCrAIY can serve as stand-alone overlay coatings or bond coats in thermal barrier coating systems, and its properties play a vital role in determining the performance of these coating systems. In order to further understand the behavior of MCrAIY coatings, several NiCoCrAIY model alloys with different levels of Re （0.3 wt%, O wt%, and 9 wt%） were investigated. Microstructural observation showed the addition of Re promoted the precipitation of Cr-rich phases, such as α-Cr and σ. The presence of α-Cr lowered the coefficient of thermal expansion （CTE） of the coating alloys, which could reduce the CTE mismatch at the scale-metal interface. The solid solution strengthening effect of Re is responsible for an increase in Rockwell hardness of the coating alloys. But the isothermal oxidation resistance at 1100℃ was deteriorated due to the precipitation of brittle α-Cr phase, a phase of inferior oxidation resistance compared with β-NiAI and γ-Ni.

关键词： NiCoCrAIY Phase constitution Oxidation Thermal expansion behavior Hardness

Development of a Compact Photoacoustic Tomography Imaging System with Dual Single-Element Transducers for Image Enhancement

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Current Medical Science 2021年第6期41卷 1151-1157页

作者： Yong-jian ZHAO Xiao-long zhu Pei-yu LUO Ang LI wei XIAO Xiao XIAO Li LIU Max q.-H.MENG Department of Electronic and Electrical Engineering the Southern University of Science and TechnologyShenzhen 518055China Department of Electronic Engineering The Chinese University of Hong KongHong Kong 999077China Shenzhen Research Institute of The Chinese University of Hong Kong in Shenzhen Shenzhen 518172China

Objective:This paper proposes a new photoacoustic computed tomography(PACT)imaging system employing dual ultrasonic transducers with different *** imaging complex biological tissues,photoacoustic(PA)signals with multiple frequencies are produced simultaneously;however,due to the limited bandwidth of a single-frequency transducer,the received PA signals with specific frequencies may be missing,leading to a low imaging ***:In contrast to our previous work,the proposed system has a compact volume as well as specific selection of the detection center frequency of the transducer,which can provide a comprehensive range for the detection of PA *** this study,a series of numerical simulation and phantom experiments were performed to validate the efficacy of the developed PACT ***:The images generated by our system combined the advantages of both high resolution and ideal brightness/***:The interchangeability of transducers with different frequencies provides potential for clinical deployment under the circumstance where a single frequency transducer cannot perform well.

关键词： photoacoustic tomography dual transducers image enhancement signal responding range

A LINE SEARCH FILTER INEXACT SqP METHOD FOR NONLINEAR EqUALITY CONSTRAINED OPTIMIZATION

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Journal of Systems Science & Complexity 2012年第5期25卷 950-963页

作者： Li CAI Detong zhu Department of Mathematics Shanghai Normal University College of Business Shanghai Normal University

This paper proposes an inexact SqP method in association with line search filter technique for solving nonlinear equality constrained optimization. For large-scale applications, it is expensive to get an exact search direction, and hence the authors use an inexact method that finds an approximate solution satisfying some appropriate conditions. The global convergence of the proposed algorithm is established by using line search filter technique. The second-order correction step is used to overcome the Maratos effect, while the line search filter inexact SqP method has q-superlinear local convergence rate. Finally, the results of numerical experiments indicate that the proposed method is efficient for the given test problems.

关键词： Constrained optimization convergence filter method inexact method maratos effect.