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Research on common issues for relationship between mechanism degree of freedom,driving link and executive link

Science china(Technological Sciences) 2009年第4期52卷 966-974页

作者： WANG AiLun college of mechanical & electrical engineering, Central South university, Changsha 410083, china Key Laboratory of Modern Complex Equipment Design and Extreme Manufacturing, Ministry of Education, Changsha 410083, china 1. college of mechanical & electrical engineering Central South University Changsha 410083 China 2. Key Laboratory of Modern Complex Equipment Design and Extreme Manufacturing Ministry of Education Changsha 410083 China

During engineering practice and theoretical research, the mechanism degree of freedom is sometimes unequal to the number of the driving link, which is unable to be explained according to the classic theory of the mechanism degree of freedom. To solve this problem, the duality description for operating laws of mechanism is introduced based on the concepts of duality. The Junction-Structure Equation is established for the port descriptions of general ideal mechanism and the functional description for the mechanism degree of freedom is described by utilization of bond graph theory. The force-transfer de- gree of freedom, i.e. the antithesis concept of movement-transfer degree of freedom, is introduced and defined based on the analysis of energy transfer as well as the analysis of signal causality. By utiliza- tion of structural description, functional description and duality description for the equation of degree of freedom, the relationship between the movement-transfer degree of freedom and force-transfer de- gree of freedom is further explored and analyzed. Thus, the relationship between the mechanism de- gree of freedom upon the driving link and the executive link is described generally. Finally, some typical relationships between the mechanism degree of freedom, the driving link and the executive link are analyzed.

关键词： duality bond graph Junction-Structure Equation driving link executive link degree of freedom

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Casing life prediction using Borda and support vector machine methods

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Petroleum Science 2010年第3期7卷 416-421页

作者： Xu Zhiqian Yan Xiangzhen Yang Xiujuan college of mechanical and Electronic engineering China University of Petroleum Dongying Shandong 257061 China college of Storage ＆ Transportation and Architectural engineering China University of Petroleum Dongying Shandong 257061 China

Eight casing failure modes and 32 risk factors in oil and gas wells are given in this paper. According to the quantitative analysis of the influence degree and occurrence probability of risk factors, the Borda counts for failure modes are obtained with the Borda method. The risk indexes of failure modes are derived from the Borda matrix. Based on the support vector machine （SVM）, a casing life prediction model is established. In the prediction model, eight risk indexes are defined as input vectors and casing life is defined as the output vector. The ideal model parameters are determined with the training set from 19 wells with casing failure. The casing life prediction software is developed with the SVM model as a predictor. The residual life of 60 wells with casing failure is predicted with the software, and then compared with the actual casing life. The comparison results show that the casing life prediction software with the SVM model has high accuracy.

关键词： Support vector machine method Borda method life prediction model failure modes riskfactors

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Multivariate Image Analysis in Gaussian Multi-Scale Space for Defect Detection

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Journal of Bionic engineering 2009年第3期6卷 298-305页

作者： Dong-tai Liang~1 Wei-yan Deng~2 Xuan-yin Wang~1 Yang Zhang~11.State Key Laboratory of Fluid Power Transmission and Control Zhejiang university,Hangzhou 310027,P.R.china2.college of mechanical and electrical engineering,china Jiliang university,Hangzhou 310018,P.R.china [a]State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 P. R. China [b]College of Mechanical and Electrical Engineering China Jiliang University Hangzhou 310018 P. R. China

Inspired by the coarse-to-fine visual perception process of human vision system,a new approach based on Gaussian multi-scale space for defect detection of industrial products was *** selecting different scale parameters of the Gaussian kernel,the multi-scale representation of the original image data could be obtained and used to constitute the multi- variate image,in which each channel could represent a perceptual observation of the original image from different *** Multivariate Image Analysis (MIA) techniques were used to extract defect features *** MIA combined Principal Component Analysis (PCA) to obtain the principal component scores of the multivariate test *** Q-statistic image, derived from the residuals after the extraction of the first principal component score and noise,could be used to efficiently reveal the surface defects with an appropriate threshold value decided by training *** results show that the proposed method performs better than the gray histogram-based *** has less sensitivity to the inhomogeneous of illumination,and has more robustness and reliability of defect detection with lower pseudo reject rate.

关键词： defect detection scale-space Gausslan multi-scale representahon principal component analysis multivariate image anaIysis

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Study on H atoms diffusion and adsorption properties of MgH_2-V systems

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Science china(Technological Sciences) 2008年第7期51卷 979-988页

作者： ZHOU DianWu1,2, LIU JinShui3 & PENG Ping3 1 State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan university, Changsha 410082, china 2 college of mechanical and Automatic engineering, Hunan university, Changsha 410082, china 3 college of Materials Science and engineering, Hunan university, Changsha 410082, china 1. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Changsha 410082 China 2. college of mechanical and Automatic engineering Hunan University Changsha 410082 China 3. college of Materials Science and engineering Hunan University Changsha 410082 China

Based on experimental results that VH0.81/MgH2 interface was found during the process of mechanically milling MgH2+5at.%V nanocomposite, H atoms diffusion and adsorption properties of MgH2-V systems have been investigated by using a first-principles plane-wave pseudopotential method based on the density functional theory. The results are as follows. When VH/MgH2 interface is formed due to V alloying MgH2 phase, the vacancy formed by H atoms near VH phase region is more stable than that without V alloying, while vacancy near MgH2 phase region is less stable than that without V alloying. During the process of H atoms diffusion after V alloying, the max migration barrier energy of H atoms in MgH2-V systems is reduced compared with that of MgH2 phase, which means that H atoms diffuse easily. When H diffuses into VH from MgH2 across VH/MgH2 interface, among three substitutions such as the replacement of H for V vacancy, or interstitial site or V atoms, the replacement of H for V vacancy has the strongest diffusion ability, next interstitial site, and finally V atoms site. As far as H adsorbed on different surfaces of VH phase is concerned, physical adsorption is carried out more easily than chemical adsorption, and the behavior of H atoms adsorbed on the surface near VH phase region can be found more easily than that near MgH2 phase region.

关键词： plane-wave pseudopotential theory magnesium hydride diffusion adsorption

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Tribological Properties of Dimpled Surface Alloying Layer on Carbon Steel

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Journal of Wuhan university of technology(Materials Science) 2009年第2期24卷 218-222页

作者：万轶 Department of Materials Science & engineering Nanjing University of Science and Technology Department of mechanical and electrical engineering Yingtian College

The effect of surface structure and coating on tribological properties of 45^# carbon steel disc was analyzed. A Nd：YAG laser was used to generate rnicrodirnples on steel surfaces. Dimples with diameter of 150 rn and depth of 50 rn were distributed in an orbicular array on disc surface. Then the alloying element Mo was sputtered to 45# carbon steel disc surface by means of double glow plasma technology. Diffusion Mo alloying layer with 30min thickness and high hardness up to 0.025 was formed on the disc surface. Tribological experiments of three types samples （smooth, texturing and texturing＋alloying） were conducted with a pin-on-disc tribometer. It is found that the dimpled-samples are most effective for reducing friction in comparison with smooth steel surthces, improving the lubricating state from boundary to hydrodynamic region.

关键词： laser surface texturing double glow plasma surface alloying technology carbon steel tribological performance lubricating state

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Research of Digital Manufacturing technology Application on Ultra-precision Optical Workpiece Machining

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武汉理工大学学报 2006年第S1期28卷 359-362页

作者： HE Daxing (School of mechanical and electrical engineering,Wuhan university of technology,Wuhan 430070,china) School of mechanical and electrical engineering Wuhan University of TechnologyWuhan 430070China

Digital manufacturing technology can be used in optical field to solve many problems caused by traditional machining. According to the characters of digital manufacturing and the practical applications of ultra-precision machining,the process of digital ultra-precision machining and its technical contents were presented in this paper. In the conclusions,it was stated that the digitalization of ultra-precision machining will be an economical and efficient way for the production of new sorts of optical workpieces.

关键词： digital manufacturing ultra-precision machining technology optical application

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PREPARATION AND PROPERTIES OF Ni-Cr AND Fe-Cr-Al FILMS BY VACUUM EVAPORATION

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Acta Metallurgica Sinica(English Letters) 2003年第4期16卷 283-288页

作者： X.W. Shi, Z.Y. Liu, B.C. Zeng and CM. LiInstitute of Materials Science & technology, college of mechanical engineering, South china university of technology, Guangzhou 510640, china Institute of Materials Science & technology College of Mechanical Engineering South China University of Technology Guangzhou 510640 China

Ni-Cr and Fe-Cr-Al films deposited on the Al2O3 substrate are studied by a method of vacuum evaporation in this paper. Influence of resistance value on density and evaporation parameters of the films reveals that the resistance of films and the adhesion of films to substrates are determined by the evaporation time and the substrate temperate under the condition of the maximum vacuity of 6.2×10-4 Pa, respectively.

关键词： vacuum evaporation resistance of film vacuity

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Observer-Based Robust Control for Measure Differential Systems with Parameter Uncertainty and Time Delay

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Systems Science and Systems engineering 2000年第3期10卷 257-263页

作者： YUE Dong\+1,\ Tso S K 2,\ Won Sangchul 3 1.college of Information & electrical engineering, china university of mining & technology, xuzhou Jiangsu, 221008, china 2.City university of Hong Kong, Hong Kong 3.Deptartment of electrical engineering, Po

In this paper, we propose a robust control based on the observer for a class of measure differential systems with time delay. To implement the control, we only need the output signal of the systems. In the finial sect... 详细信息

关键词： observer measure differential systems stability

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s-ordering operator expansions of quantum-mechanical fundamental representations and their applications

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Science china(Physics,Mechanics & Astronomy) 2011年第12期54卷 2150-2154页

作者： FAN HongYi 1,3 , XU YeJun 2 & YUAN HongChun 3,4 1 Department of Materials Science and engineering, university of Science and technology of china, Hefei 230026, china 2 Department of Physics Electronic and engineering, Chizhou university, Chizhou 247000, china 3 Department of Physics, Shanghai Jiao Tong university, Shanghai 200030, china 4 college of Optoelectronic engineering, Changzhou Institute of technology, Changzhou 213002, china 1. Department of Materials Science and engineering University of Science and Technology of China Hefei 230026 China3. Department of Physics Shanghai Jiao Tong University Shanghai 200030 China2. Department of Physics Electronic and Engineering Chizhou University Chizhou 247000 China4. College of Optoelectronic Engineering Changzhou Institute of Technology Changzhou 213002 China

We show that the quantum-mechanical fundamental representations, say, the coordinate representation, the coherent state representation, the Fan-Klauder entangled state representation can be recast into s-ordering operator expansion, which is elegant in form and has many applications in deriving new operator identities. This demonstrates that Dirac's symbolic method can be merged into Newton-Leibniz integration theory in a broad way.

关键词： s-ordering operator expansion operator identities quantum mechanical representation

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TRANSMISSION MOMENTARY EFFICIENCY BASED ON THE D'ALEMBERT-LAGRANGE EQUATION FOR INVOLUTES GEARS

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Chinese Journal of mechanical engineering 2004年第2期17卷 272-275页

作者： Liang Yi Lai Changying School of mechanical engineering,Nanjing university of Science and technology,Nanjing 210094, china School of mechanical engineering Nanjing University of Science and Technology Nanjing 210094 China Department of Science and technology Studies University College London WC1E 6BT UK

The D'Alembert-Lagrange equation is introduced and used to derive theformulas of momentary efficiency for external gearing of standard involutes spur gears. The gearingswith correct and increased center distance are discussed. The momentary efficiency formula iscalculated and analyzed using software Matlab. The derived formula of momentary efficiency is alsocompared with the traditional formula.

关键词： D'Alembert-Lagrange equation Involutes gear Momentary efficiency

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