GLOBAL SMOOTH SOLUTIONS TO THE SYSTEM OF ONE-IMMENSIONAL THERMOELASTICITY WITH DISSIPATION BOUNDARY CONDITIONS

In this paper, the authors consider the initial boundary value problem for the a system of one-domensional thermoelasticity with dissipation conditions. By means of the delicate energy estimates and the continuation argument, the authors proved the global existence uniqueness and the exponential decay of smooth solutions provided that the initial data are sufficiently small 。     

EXISTENCE AND NON-EXISTENCE OF GLOBAL SMOOTH SOLUTIONS FOR QUASILINEAR HYPERBOLIC SYSTEMS~*

Consider initial value probiom v_t-u_x=0, u_t+p(v)_x=0, (E), v(x, 0)=v_0(x), u(x, 0)=u_0(x), (I), where A≥0, p(v)=K~2v~(-γ), K>0, 0<γ<3. As 0<γ≤1, the authors give a sufficient condition for that (E), (I) to have a unique global smooth solution, As 1≤γ<3, a necessary condition is given for that.     

具非线性边界条件的拟线性抛物型方程解的Blow-up

本文考虑一类具非线性边界条件的拟线性抛物方程初边值问题解的整体性态 .通过构造与解有关的适当积分 ,利用“凸性方法”及非线性抛物型方程的极大值原理 ,证明了在某些条件下 ,问题的光滑解u(x ,t)只能在一个有界区间 (0 ,T0 )中存在 ,即有 :limt→T-0sup‖u(· ,t)‖ ∞ =+∞ .     

GLOBAL EXISTENCE AND EXPONENTIAL STABILITY OF SOLUTIONS TO THE QUASILINEAR THERMO-DIFFUSION EQUATIONS WITH SECOND SOUND

This article is devoted to the study of global existence and exponential stability of solutions to an initial-boundary value problem of the quasilinear thermo-diffusion equations with second sound by means of multiplicative techniques and energy method provided that the initial data are close to the equilibrium and the relaxation kernel is strongly positive definite and decays exponentially.     

EXISTENCE OF GLOBAL SMOOTH SOLUTIONS FOR TWO IMPORTANT NONSTRICTLY QUASILINEAR HYPERBOLIC SYSTEMS

（朱长江）（赵会江）ＥＸＩＳＴＥＮＣＥＯＦＧＬＯＢＡＬＳＭＯＯＴＨＳＯＬＵＴＩＯＮＳＦＯＲＴＷＯＩＭＰＯＲＴＡＮＴＮＯＮＳＴＲＩＣＴＬＹＱＵＡＳＩＬＩＮＥＡＲＨＹＰＥＲＢＯＬＩＣＳＹＳＴＥＭＳ￥ＺｈｕＣｈａｎｇｊｉａｎｇ；ＺｈａｏＨｕｉｊａｎｇ（Ｗｕ...     

BLOW-UP OF SOLUTIONS TO ELLIPTIC EQUATIONS WITH SEMILINEAR DYNAMICAL BOUNDARY CONDITIONS OF HYPERBOLIC TYPE

In this paper,we present some sufficient conditions for blow-up of soluti- ons to elliptic equations under semilinear dynamical boundary conditions of hyperbolic type.     

一类三阶拟线性发展方程的整体解

本文研究一类三阶拟线性发展方程ｕｔｔ－Δｕｔ＋ｕｔ＝ｎｉ＝１ｘｉσｉ（ｕｘｉ），（ｘ，ｔ）∈Ω×（０，Ｔ）的初边值问题，其中ΩＲｎ（ｎ≥１）为一有界域．证明了只要σｉ（ｓ）∈Ｃ１，σ′ｉ（ｓ）（ｉ＝１，…，ｎ）有界并且初始函数满足一定的条件，则上述问题存在唯一的整体弱解．     

THE EXISTENCE OF POSITIVE SOLUTIONS TO BOUNDARY VALUE PROBLEM OF SECOND ORDER DIFFERENTIAL EQUATIONS

In this paper, a fixed point theorem in C1[0,1] space is established using the properties of the fixed point index. This theorem is applied to prove the existence of positive solution to the boundary value problems of second order differential equations.     

边界耦合的牛顿渗流方程组解的整体存在与爆破

本文研究了由边界条件耦合的多维牛顿渗流方程组解的长时间行为.利用构造的多种上下解,得到了整体存在临界曲线与Fujita临界曲线.     

ASYMPTOTIC BEHAVIOR OF SOLUTIONS TO A CLASS OF SECOND ORDER QUASILINEAR DIFFERENTIAL EQUATIONS WITH DELAY DEPENDING ON THE UNKNOWN FUNCTION

The asymptotic behavior of the solutions to a class of second order quasilinear differential equations is considered. The main results improve and generalize those in Elbert and Kusano [3].     

二阶微分方程边值问题的多重正解

基于Leray-Schauder度理论和上下解方法讨论非线性边值问题(t)+g(t,y)=0,(0)=0,y(1)=b≥0的正解存在性,其中g局部Lipschitz连续,g(t,0)≥0,但是可以是变号函数。主要结论是:如果g(t,y)在y=+∞满足一个超线性增长条件,并且存在使得β(1)>0的非负上解β,则存在正数B使得当0B时,不存在正解。     

二阶拟线性混合（椭圆—双曲）型方程的Frankl问题

本文证明了一类二阶阶拟线性混合型方程Frankl边值问题解的唯一性与存在性,文中先给出解后一种表示式,据此证明边值问题解的唯一性,进而求得解的估计式,据此再使用复分析理论与“参数开拓法”证明了边值问题解的存在性,这里使用的方法有别于其他作者对混合型方程通常使用的积分方程方法。     

ON THE OSCILLATION OF CERTAIN SECOND ORDER QUASILINEAR NEUTRAL DIFFERENTIAL EQUATIONS

Some new oscillation theorems for a second order superlinear-sublinear neutral differential equation are established under some conditions. Our results improve and extend the main results in the previous literature. Explicit examples related to the main results are given.     

二阶拟线性混合(椭圆一双曲)型方程的Frankl问题

本文证明了一类二阶拟线性混合型方程Frankl边值问题解的唯一性与存在性.文中先给出解的一种表示式,据此证明边值问题解的唯一性.进而求得解的估计式,据此再使用复分析理论与"参数开拓法”证明了边值问题解的存在性.这里使用的方法有别于其他作者对混合型方程通常使用的积分方程方法.     

GLOBAL CLASSICAL SOLUTIONS TO QUASILINEAR HYPERBOLIC SYSTEMS WITH WEAK LINEAR DEGENERACY

§1. Introduction and Main Results Consider the following ?rst order quasilinear strictly hyperbolic system ?u ?u A(u) = 0, (1.1) ?t ?xwhere u = (u1, ···,un)T is the unknown vector function of (t,x) and A(u) is an n×n matrixwith suitably smooth elements aij(u) (i,j = 1, ···,n). By the de?nition …     

ASYMPTOTIC BEHAVIOR OF SOLUTIONS TO THE HEAT EQUATIONS WITH NONLINEAR BOUNDARY CONDITIONS

The purpose of this paper is to investigate the stability and asymptotic behav-ior of the time-dependent solutions to a linear parabolic equation with nonlinear boundarycondition in relation to their corresponding steady state solutions. Then, the above resultsare extended to a semilinear parabolic equation with nonlinear boundary condition by an-alyzing the corresponding eigenvalue problem and using the method of upper and lowersolutions.     

一类修正的Navier—Stokes方程组Neumann边值问题的弱解

讨论一类修正的Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ型方程组Ｎｅｕｍａｎｎ边值问题的可解性及解的性质。     

二阶拟线性中立型时滞微分方程的振动性

考虑二阶中立型时滞微分方程[a(t)|(x(t) p(t)x(t-τ)）′|^α-1(x(t) p(t)x(t-τ））′]′ f(t,x(t-σ））=0(E)其中α，τ，σ是非负常数，a(t),p(t)∈C([t0,∞），R），f(t,x)∈C(R,R)。建立了方程（E）的一些新的振动条件。