不同材料的两个各向同性弹性长条的焊接问题

利用复变方法和积分方程理论 ,讨论两个不同材料的各向同性弱性长条的焊接问题 ,在理论上 ,给出了弱性体应力分布封闭形式的解 .     

Existence of Positive Solutions for Eigenvalue Problems of Fourth-order Elastic Beam Equations

In this paper,we investigate the positive solutions of fourth-order elastic beam equations with both end-points simply supported.By using the approximation theorem of completely continuous operators and the global bifurcation techniques,we obtain the existence of positive solutions of elastic beam equations under some conditions concerning the first eigenvalues corresponding to the relevant linear operators,when the nonlinear term is non-singular or singular,and allowed to change sign.     

非线性弹性体的弹性动力学变分原理

本文根据文献[1],对非线性应力应变关系的弹性体,导出了弹性动力学问题的变分原理和广义变分原理,提出了混合位移协调元和混合应力协调元的瞬时广义变分原理.     

The transmission problem in bending of plates with transverse shear deformation

The existence of weak solutions is proved for contact problemsin bending of elastic plates with transverse shear deformation,and for various boundary integral equations arising from potentialrepresentations of such solutions.     

On the global well-posedness of the 3D viscous primitive equations

Here we consider the global well-posedness of the 3D viscous primitive equations of the large-scale ocean. Inspired by the methods in Cao etc\cite{CT3} and Guo etc\cite{GH2}, we prove the global well-posedness and the long-time dynamics for the primitive equations.     

Dynamics of a Rational Difference Equation

The authors investigate the global behavior of the solutions of the difference equation xn＋1=axn-1xn-k/bxn-p＋cxn-q,n=0,1,…where the initial conditions x-r, x-r＋1, x-r＋2,… , x0 are arbitrary positive real numbers, r = max{l, k,p, q） is a nonnegative integer and a, b, c are positive constants. Some special cases of this equation are also studied in this paper.     

On the Dynamics of the Classical Transverse Field Ising Chain

We investigate stationary and travelling wave solutions of a special lattice differential equation in one space dimension. Depending on a parameter λ, results are given on the existence, shape and stability for these kind of solutions. The analysis of travelling wave solutions leads us to a functional differential equation with both forward and backward shifts. The existence of solutions of this equation will be proved by use of the implicit function theorem. In particular, we consider kink solutions and periodic solutions.     

On the Oscillation of the Fourth Order Differential Equations

61.IntroductionWeconsiderthefourthorderdifferentialequationx(`)(t)-p(t)lx(t)I'sgnx(t)=O,(1.l)wherea>l,isconstant,andp(t)ispositivecontinuousfunctionon[t,,oo),to>o.Werestrictourattentiontothosenontrivialsolutionsx(t)of(1.1)whichexistonsomehalf-[ine[T:,co)cy[t,,oo),suchasolutioniscalledapropersolutionof(1.l).ApropersolutioniscalledoscillatoryifithasarbitrarilylargezerosFotherwiseitiscallednonoscillatory.Wecon-sidertheoscillationandnonoscillationofpropersolutionsof(l,l).WeletEdenotethesetofall…     

On the definition of viscosity solutions for parabolic equations

In this short note we suggest a refinement for the definition of viscosity solutions for parabolic equations. The new version of the definition is equivalent to the usual one and it better adapts to the properties of parabolic equations. The basic idea is to determine the admissibility of a test function based on its behavior prior to the given moment of time and ignore what happens at times after that.

     

抽象空间常微分方程弱解的存在和唯一性

本文研究了抽象空间中初值问题ｘ′＝ ｆ（ｔ,ｘ）,ｘ（ｔ０）＝ ｘ０ 的弱解存在和唯一性,并推广了文［１］、［２］中的有关结果     

On equations in inverse semigroups

Let S be an inverse semigroup generated by a set . An equation in S is an expression , are terms of the type . Received September 20, 2000; accepted in final form May 8, 2001.     

有限变形极性弹性介质的各型动力学方程组*

本文从Dluzewski提出的以欧拉角为角坐标的建议和推导出的Cauchs型动力学方程组出发,又引进若干有关变形几何学和动力学的新定义并推导出有限变形极性弹性介质的Boussinesq型、Kirchhoff型、Signorini型和Новожилов型动力学方程组．     

两个不同正交各向异性弹性长条的焊接问题

本文利用弹性复变方法和积分方程理论,讨论两个不同材料正交各向异性弹性长条的焊接问题,给出一种新的算法,改进通常单一的积分变换方法,理论上,得出了应力分布封闭形式的解．     

四阶脉冲弹性梁方程非平凡弱解的存在数量

本文研究了一类具有脉冲项的四阶弹性梁微分方程边值问题,在非线性项不连续的情况下利用变分方法结合相应的临界点定理得到了非平凡弱解的存在数量,最后给出具体的例子,结合牛顿迭代法来验证所得到的结论.     

The Three-Dimensional Problem of Statics of the Elastic Mixture Theory with Displacements Given on the Boundary

The first three-dimensional boundary value problem is considered for the basic equations of statics of the elastic mixture theory in the finite and infinite domains bounded by the closed surfaces. It is proved that this problem splits into two problems whose investigation is reduced to the first boundary value problem for an elliptic equation which structurally coincides with an equation of statics of an isotropic elastic body. Using the potential method and the theory of Fredholm integral equations of second kind, the existence and uniqueness of the solution of the first boundary value problem is proved for the split equation.     

On the Dynamics of

We investigate the existence of unbounded solutions and the period-two convergence of solutions of the equation in the title with the parameter γ positive, the remaining parameters nonnegative, and with nonnegative initial conditions.     

On the asymptotics of some difference equations

We prove two inclusion theorems regarding a difference equation and apply them in getting the asymptotics of positive solutions of some concrete difference equations.     

On the existence of solutions of nonlinear equations

Results on the existence of solutions are derived for asymptotically quasilinear, nonlinear operator equations. Applications are given to implicit nonlinear integral equations.

     

On the growth of entire solutions of algebraic differential equations

This is the opening memorial plenary lecture on memorial meeting in honor of Professor Shlomo Strelitz on Conference of Differential Equations and Complex Analysis, University of Haifa, Israel, December 2000. Shlomo Strelitz: 7.1.1923–27.9.1999, teached at Vilnius University 1946–1973, professor 1967–1973.__________Published in Lietuvos Matematikos Rinkinys, Vol. 45, No. 1, pp. 57–63, January–March, 2005.