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A PERTURBATION PROCEDURE FOR LIMIT CYCLE DETERMINATION IN THREE-DIMENSIONAL NONLINEAR AUTONOMOUS DYNAMICAL SYSTEMS

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A PERTURBATION PROCEDURE FOR LIMIT CYCLE DETERMINATION IN TH...

Structure and Mixed Electronic-ionic Conducting Properties of La_(0.6)Sr_(0.4)Co_(1-y)Fe_yO_3(y=0-1.0) Ceramics Made by a Citrate Method

庆祝中国力学学会成立50周年暨中国力学学会学术大会’2007

作者： SHEN JH CHEN SH~(2)) (department of applied Mechanics and engineering,Sun Yat-sen university,Guangzhou,510275,P.R.China)

By introducing a new parametric transformation and suitable nonlinear frequency expansion in the perturbation procedure of the modified Lindstedt-Poincare method,analytical approximation for limit cycle in a three-dim... 详细信息

关键词： analytical approximation limit cycle nonlinear autonomous systems modified Lindstedt-Poincare method

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Journal of Wuhan university of Technology(Materials Science) 2008年第1期23卷 80-84页

作者：黄端平徐庆 school of Materials Science and engineering Wuhan University of Technology

La0.6Sr0.4Co1-yFeyO3（y= 0-1.0） powders were synthesized by a citrate method, and the structure and mixed electronic-ionic conducting properties of the resulting ceramics were investigated. The synthesized La0.6Sr0.4Co1-yFeyO3 powders have a pure perovskite structure and consist of uniform and fine particles. A perovskite struciure with rhombohedral symmetry was certified for the La0.6Sr0.4Co1-yFeyO3 ceramics. The increase of Co/Fe ratio significantly promoted the grain growth and microstructural densification. The La0.6Sr0.4Co1-yFeyO3 compositions with relatively higher Co/Fe ratio exhibit superior mixed conducting properties. The electronic structure and microstructure of the ceramics are responsible for the variation of the mixed conducting properties with Co/Fe ratio.

关键词： ceramics oxides chemical synthesis microstructure electrical properties

NUMERICAL SIMULATION OF HIGHLY UNDEREXPANDED AXISYMMETRIC JET WITH RUNGE-KUTTA DISCONTINUOUS GALERKIN FINITE ELEMENT METHOD

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Journal of Hydrodynamics 2008年第5期20卷 617-623页

作者： CHEN Er-yun MA Da-wei LE Gui-gao WANG kai ZHAO Gai-ping school of Mechanical engineering Nanjing University of Science and Technology Nanjing 210094 China school of Medical Instrument Shanghai university of Science and Technology Shanghai 200093 China

Highly undcrexpanded axisymmctric jet was simulated using the Runge-Kutta Discontinuous Galerkin （RKDG） finite element method, which, based on two-dimensional conservation laws, was used to solve the axisymmetric Euler equations. The computed results show that the complicated flow field structures of interest, including shock waves, slipstreams and the triple point observed in experiments could be well captured using the RKDG finite element method. Moreover, comparisons of the Mach disk location exhibit excellent agreements between the computed results and experimental measurements, indicating that this method has high capability of capturing shocks without numerical oscillation and artificial viscosity occurring near the discontinuous point.

关键词： underexpanded jct shock RKDG finite element method

Strength and damage of marble in ductile failure

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Journal of Rock Mechanics and Geotechnical engineering 2011年第2期3卷 161-166页

作者： Mingqing You school of Energy Science and engineering, Henan Polytechnic university, Jiaozuo, 454010, China school of Energy Science and engineering Henan Polytechnic University Jiaozuo 454010 China

To study the effects of loading paths and stress states on rock strength and deformation, marble specimens were axially compressed to various displacements under a confining pressure (CP) firstly, and then the damaged specimens were recompressed under another CP. The bearing capacity of a marble specimen depends merely on CP at the stage of ductile deformation, and it has no relation with the loading history when CP keeps constant or increases. However, the damaged specimen turns into brittle when it is recompressed uniaxially or at a lower CP, and the Young’s modulus and strength are lower than those of a dense specimen. The increasing ratio of triaxial strength to CP has a close relation with the areas of fissures in the damaged specimens but not the internal friction angle. Material strength and bearing capacity are two different conceptions for rocks. Material strength decreases continually as the plastic deformation increases; however, the bearing capacity is determined by both the stress state and the material strength.

关键词： rock mechanics brittle-ductile damage strength Young’s modulus

Gene association study with SVM,MLP and cross-validation for the diagnosis of diseases

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Progress in Natural Science:Materials International 2008年第6期18卷 741-750页

作者： Junying Zhanga,*,Shenling Liu a,Yue Wang b aschool of Computer Science and engineering,Xidian university,161 Postbox,Xi’an 710071,China bdepartment of Electrical and Computer engineering,Virginia Polytechnic Institute and State university,Alexandria,VA 22314,USA school of Computer Science and engineering Xidian University 161 Postbox Xi’an 710071 China department of Electrical and Computer engineering Virginia Polytechnic Institute and State University Alexandria VA 22314 USA

Gene association study is one of the major challenges of biochip technology both for gene diagnosis where only a gene subset is responsible for some diseases,and for the treatment of the curse of dimensionality which occurs especially in DNA microarray datasets where there are more than thousands of genes and only a few number of experiments(samples).This paper presents a gene selection method by training linear support vector machine(SVM)/nonlinear MLP(multilayer perceptron)classifiers and testing them with cross-validation for finding a gene subset which is optimal/suboptimal for the diagnosis of binary/multiple disease *** are selected with linear SVM classifier for the diagnosis of each binary disease types pair and tested by leave-one-out cross-validation;then,genes in the gene subset initialized by the union of them are deleted one by one by removing the gene which brings the greatest decrease of the generalization power,for samples,on the gene subset after removal,where generalization is measured by training MLPs with leave-one-out and leave-four-out *** proposed method was tested with experiments on real DNA microarray MIT data and NCI *** result shows that it outperforms conventional SNR method in the separability of the data with expression levels on selected *** real DNA microarray MIT/NCI data,which is composed of 7129/2308 eective genes with only 72/64 labeled sam-ples belonging to 2/4 disease classes,only 11/6 genes are selected to be diagnostic *** selected genes are tested by the classification of samples on these genes with SVM/MLP with leave-one-out/both leave-one-out and leave-four-out *** result of no misclassification indicates that the selected genes can be really considered as diagnostic genes for the diagnosis of the corresponding diseases.

关键词： DNA microarray data Curse of dimensionality Gene selection Diagnostic genes SVM MLP Cross-validation

Entropic stochastic resonance in a confined structure driven by dichotomous noise and white noises

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Chinese Physics B 2012年第8期21卷 71-77页

作者：郭锋程晓锋李少甫曹文黎恒 school of Information engineering Southwest University of Science and Technology Research Center of Laser Fusion China Academy of Engineering Physics

The entropic stochastic resonance （ESR） in a confined system subjected to dichotomous noise and white noise and driven by a periodic sinusoidal force along the x axis of the structure and a time-dependent force in the declining direction, is investigated. Under the adiabatic approximation condition and based on the two-state theory, the expression of the output signal-to-noise ratio （SNR） is obtained. The results show that the SNR is a non-monotonic function of the strengths of dichotomous noise, white noise, and correlated strength of correlated noise. In addition, the SNR varies non-monotonically with the increase of the shape parameters of the confined structure, and also with the increase of the constant force along the y axis of the structure. The influence of the correlation rate of the dichotomous noise, and that of the frequency of the periodic force on the SNR are discussed.

关键词： entropic stochastic resonance dichotomous noise correlated noise square-wave signal,signal-to-noise ratio

A Mathematical Model for EstimatingElectroosmosis Effect on Water Displacing Oil Process in Porous Media and Its Application

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Journal of Earth Science 1999年第3期18卷 241-244页

作者： Yun Junxian (Chemical engineering Institute, Dalian university of Technology, DaLian 116012)Zhang Ningsheng Zhang Wei Wu Xinmin(department of Petroleum engineering, Xi’an Petroleum Institute, Xi’an 710065) Chemical engineering Institute Dalian University of Technology DaLian 116012 department of Petroleum engineering Xi'an Petroleum Institute Xi'an 710065

A mathematical model based on Darcy's law and electroosmosis equation in porous media is developed and two parameters named electroosmosis coefficient K, and relative electroosmosis coefficient Kre are used to calculate the curves of Ke and Krevs. water saturation whick are employed to estimate the effect of electroosmosis on water displacing oil process in sandstone cores. Under the conditions of constant injection rate displacement and constant electrical potential gradient, the method to calculate parameters K. and K. at different water saturation is developed and unsteadystate displacement *** data under the effect of electroosmosis are used to determine the Parameter values. The results show that K, and K, are increased firstly with increasing water saturation and then decreased. This trend shows the inter-relationship between electroosmosis and the water displacing oil process. Finally, application of the model to ECMP mechauics studies and ac-tual reservoirs is analyzed in this peper.

关键词： electroosmosis mathematical model electrical-chemical producing method displacement experiment porous media

晶体物理主轴坐标系对三阶有效非线性系数的影响

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上海交通大学学报 1996年第3期30卷 16-20页

作者：杨学林谢绳武陈康上海交通大学材料科学与工程系上海上海交通大学应用物理系上海

由于晶体的折射率主轴与其晶体物理主轴有着不同的配对方式，其三阶有效非线性系数计算公式将发生变化．考虑到配对方式的影响，首次得到变换后的三阶非线性系数的矩阵形式，然后推导出了任意配对方式下，晶体主平面上三阶有效非线性系... 详细信息

由于晶体的折射率主轴与其晶体物理主轴有着不同的配对方式，其三阶有效非线性系数计算公式将发生变化．考虑到配对方式的影响，首次得到变换后的三阶非线性系数的矩阵形式，然后推导出了任意配对方式下，晶体主平面上三阶有效非线性系数的最一般解析表达式．

关键词：晶体物理主轴折射率主轴非线性光学系数晶体

The Cultivating of engineering Human Resource Baced on AMT

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International Journal of Plant engineering and Management 2003年第2期8卷 108-114页

作者： LIU Bo, SUN Lin-yan department of Industrial engineering, Management school, Xi′an Jiaotong university, Xi′an 710049, P.R. China department of Industrial engineering Management School Xi'an Jiaotong University Xi'an 710049 P. R. China

This paper firstly analyzes the features and developing tendency of AMT. Then starting from studying the challenges of AMT that qualified IE specialists have to face, it systematically analyzes the problems that part of a qualified IE specialist′s education can not fit to the development of AMT, discussing some root causes of these problems. Finally, it puts forward the idea for training of qualified IE specialists that should adapt to the development of AMT.

关键词： advanced manufacturing technology (AMT) engineering technology human resources industrial engineering(IE)