检索结果-南通市图书馆

Boundary conditions for the bending of a piezoelectric beam

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china(Physics,Mechanics & Astronomy) 2008年第7期51卷 847-856页

作者： GAO Yang1, XU SiPeng2 & ZHAO BaoSheng3 1 college of science, china Agricultural university, Beijing 100083, china 2 college of Engineering, Ocean university of china, Qingdao 266071, china 3 School of Mechanical Engineering, university of science and Technology Liaoning, Anshan 114044, china college of science China Agricultural University Beijing China college of Engineering Ocean University of China Qingdao China School of Mechanical Engineering University of Science and Technology Liaoning Anshan China

For beam bending in transversely isotropic piezoelectric media, the reciprocal theorem and the general solution of piezoelasticity are applied in a novel way to obtain the appropriate stress and mixed boundary conditions accurate to all orders for the beam of general edge geometry and loadings. By generalizing the method developed by Gregory and Wan, a set of necessary conditions on the edge-data for the existence of a rapidly decaying solution is established. The prescribed edge-data of the beam must satisfy these conditions in order that they could generate a decaying state within the beam. When stress and mixed conditions are imposed on the beam edge, these decaying state conditions for the case of bending deformation of piezoelectric beam are derived explicitly. They are then used for the correct formulation of boundary conditions for the beam theory solution (or the interior solution). Besides, an analytical solution of elastic beam is formulated to verify validity of our boundary conditions. For the stress data, our boundary conditions coincide with those obtained in conventional forms of beam theories. More importantly, the appropriate boundary conditions with two sets of mixed edge-data are obtained for the first time.

关键词： boundary conditions beam bending piezoelectric media decaying states regular states

Duality properties between spectra and tilings

在线全文

学校读者我要写书评

暂无评论

science china mathematics 2010年第5期53卷 270-280页

作者： LI JianLin college of mathematics and Information science,Shaanxi Normal university,Xi’an 710062,china college of mathematics and Information science Shaanxi Normal University

Spectra and tilings play an important role in analysis and geometry *** relations between spectra and tilings have bafied the mathematicians for a long *** conjectures,such as the Fuglede conjecture,are placed on the establishment of relations between spectra and tilings,although there are no desired *** the present paper we derive some characteristic properties of spectra and tilings which highlight certain duality properties between them.

关键词： spectral pair periodic set packing and covering tiling pair

On a problem of Skiba from the Kourovka Notebook

在线全文

学校读者我要写书评

暂无评论

science china mathematics 2004年第1期47卷 96-103页

作者： WANG Yanming & WEI HuaquanLingnan college and School of mathematics, Zhongshan university, Guangzhou 510275, china School of mathematics, Zhongshan university, Guangzhou 510275, china Department of mathematics, Guangxi Teacher’s college, Nanning 530001, china Lingnan college and School of mathematics Zhongshan University Guangzhou China School of mathematics Zhongshan University Guangzhou China Department of mathematics Guangxi Teacher’s College Nanning China

In this paper, we give a positive answer to a recent open problem of Skiba in Kourovka Notebook without using the odd order theorem and other deep theorems. Some of the techniques are improved.

关键词： supersolvable group c-supple merited subgroup complemented subgroup generalized fitting subgroup saturated formation

A RCK Model with Endogenous Fertility and Exogenous Technological Change

在线全文

学校读者我要写书评

暂无评论

Wuhan university Journal of Natural sciences 2000年第2期5卷 137-142页

作者： CAI Dong han college of mathematics and Computer science, Wuhan university, Wuhan 430072, china college of mathematics and Computer science Wuhan University Wuhan 430072 China

The technological change as an exogenous variable is introduced into the RCK model with endogenous fertility in this paper. It is proved that the model has at least a nonzero steady state and the nonzero steady state is unique when the parameters satisfies some conditions. By phrase protrait analysis, the unique nonzero steady state is saddle and the economy has a unique optimal growth path. The results obtained implies that the relationship between the technological change and population growth rate determinated by the economic structure and the parental ethies. For the economy in which the parents is selfish, promoting the technological change rate decreases the fertility at the steady state. On the other hand, for the economy in which the parents is less selfish, the fertility increases as the technological change rate increases.

关键词： C K model fertility technological change economic growth

Mixed boundary conditions for piezoelectric plates

在线全文

学校读者我要写书评

暂无评论

science china(Physics,Mechanics & Astronomy) 2009年第5期52卷 755-761页

作者： GAO Yang 1 ,XU SiPeng 2 &ZHAO BaoSheng 3 1college of science,china Agricultural university,Beijing 100083,china 2college of Engineering,Ocean university of china,Qingdao 266071,china 3 School of Mechanical Engineering,university of science and Technology of Liaoning,Anshan 114044,china college of science China Agricultural University Beijing China college of Engineering Ocean University of China Qingdao China School of Mechanical Engineering University of Science and Technology of Liaoning Anshan China

For plate bending and stretching problems in piezoelectric materials,the reciprocal theorem and the general solution of piezoelasticity are applied in a novel way to obtain the appropriate mixed boundary conditions accurate to all order.A decay analysis technique is used to establish necessary conditions that the prescribed data on the edge of the plate must satisfy in order that it should generate a decaying state within the *** the case of axisymmetric bending and stretching of a circular plate,these decaying state conditions are obtained explicitly for the first time when the mixed conditions are imposed on the plate *** are then used for the correct formulation of boundary conditions for the interior solution.

关键词： boundary conditions piezoelectric plates mixed data bending problems stretching problems

ON THE LEAST SQUARES PROBLEM OF A MATRIXEQUATION

在线全文

学校读者我要写书评

暂无评论

Journal of Computational mathematics 1999年第6期17卷 589-594页

作者： An-ping Liao(college of science, Hunan Normal university, Changsha 410081, china) 湖南师范大学理学院湖南长沙 410081

Least squares solution of F=PG with respect to positive semidefinite symmetric P is considered,a new necessary and sufficient condition for solvablity is given,and the expression of solution is derived in the some special cases. Based on the expression, the least spuares solution of an inverse eigenvalue problem for positive semidefinite symmetric matrices is also given.

关键词： least squares solution matrix equation inverse eigenvalue problem positive semidefinite symmetric matrix

THE CONVERGENCE OF A NEW MODIFIED BFGS METHOD WITHOUT LINE SEARCHES FOR UNCONSTRAINED OPTIMIZATION OR COMPLEXITY systemS

在线全文

学校读者我要写书评

暂无评论

Journal of systems science & Complexity 2010年第4期23卷 861-872页

作者： Liying LIU Zengxin WEI Xiaoping WU college of mathematics science Liaocheng University Liaocheng 252059 China college of mathematics and Information science Guangxi University Nanning 530004 China School of Management Xi'an Jiaotong University Xi'an 710049 China

In this paper,a new modified BFGS method without line searches is *** traditionalBFGS method,this modified BFGS method is proposed based on the so-called fixed steplengthstrategy introduced by Sun and *** some suitable assumptions,the global convergence andthe superlinear convergence of the new algorithm are established,*** some preliminarynumerical experiments,which shows that the new Algorithm is feasible,is also reported.

关键词： BFGS method complexity systems global convergence superlinear convergence unconstrained optimization.

Heteroclinic orbits and heteroclinic chains for a discrete Hamiltonian system

在线全文

学校读者我要写书评

暂无评论

science china mathematics 2010年第6期53卷 1555-1564页

作者： ZHANG Hao & LI ZhiXiang Department of mathematics and systems science,college of science,National university of Defense Technology,Changsha 410073,china Department of mathematics and systems science College of Science National University of Defense Technology

In the present work we prove some existence results of heteroclinic orbits and heteroclinic chains for a second order discrete Hamiltonian system of the form Δ2q(t-1)+V(q(t))=0,t∈*** methods we use are variational in *** results show that under general conditions,for each maximum point β of V,the above system possesses multiple heteroclinic orbits joining β and some other maximum points of *** also prove that for any pair of distinct maximum points η and ξ of V,there exists at least one heteroclinic chain from η to ξ.

关键词： difference equation heteroclinic orbit heteroclinic chain variational method

Existence of Single-Peaked Solution of a Semilinear Elliptic Problem

在线全文

学校读者我要写书评

暂无评论

Wuhan university Journal of Natural sciences 2000年第4期5卷 386-390页

作者： Zhong Xin-hua college of mathematics and Computer science,Wuhan university,Wuhan 430072,china college of mathematics and Computer science Wuhan UniversityWuhan 430072China

We discussed the Dirichlet problem of semilinear elliptic equation (P β,ε):β 2Δu=u p +εu,u>0, in Ω;u=0, on ?Ω, where Ω?R N (N≥4) is smooth and bounded domain, ,β,ε>0. We have proved that there exist positiveε 0 andε 1, such that when 0?ε?ε 0,β>√ε 1, (P β,ε) has a single-peaked solutionu β,ε; furthermore, |?u β0|2?0 in the sense of measure as ε→0 and β→0.

关键词： semilinear critical growth single-peaked solution