关于一类非线性发展方程整体解的存在性问题

本文研究一类模拟非线性弹性杆的纵振动的非线性发展方程的初边值问题，证明了其整体解的存在性、唯一性、光滑性及在一定条件下，整体解的不存在性。     

一类带非线性边界条件的非线性抛物方程的解的整体存在性

该文考虑带非线性边界条件的非线性抛物方程的正整体解的存在性与非存在性。通过使用上下解技巧，得到了所有正解整体存在的充分必要条件。作者所构造的上下解具有相同的形式且计算简便。     

一类二阶非线性发展方程整体解的渐近性

本文应用一个差分不等式证明了一类二阶非线性发展方程初边值问题整体解的衰减性质.     

一类广义非线性Euler-Poisson-Darboux方程整体解的渐近性质

W.A.Strauss等人已证明了广义非线性 Euler-Poisson-Darboux方程初边值问题整体解的存在唯一性 .本文应用一个差分不等式研究了整体解的渐近性质 .     

一类非线性双曲方程整体弱解的存在性与不存在性

讨论了一类非线性双曲方程uu-a1△u-a2n∑i=1 / xi(｜uxi｜^-1)-a3△ut=0的初边值问题整体弱解的存在性与不存在性和指数衰减。     

一类具有非线性阻尼和源项的Petrovsky方程整体解的存在性与渐近性

研究了一类具有非线性阻尼和源项的Petrovsky方程u_(tt) △~2u au_t|u_t|~(m-2)= bu|u|~(p-2)的初边值问题.在对m,p的大小关系不加任何限制的情况下,利用稳定集证明了整体解的存在性,并且得到了整体解的渐近性质.     

一类非线性蜕化方程的整体吸引子

研究了一类非线性蜕化方程。引入带权Ｌ＾２空间,证明了方程初边值问题整体解的存在唯一性,并在无穷维空间证明了（Ｅ０,Ｅ）型整体吸引子的存在性。     

一类非线性发展方程组整体解的存在性和不存在性

本文考虑如下非线性发展方程组的初边值问题u″+ Au -△ u′-α| v|ρ+ 2 | u|ρu =0 ,　 v″+ Av -△ v′-α| u|ρ+ 2 | v|ρv =0 ,其中 A为 p-Laplace算子 ,α∈ R,ρ>-1均为常数 ,证明了整体解的存在性及渐近性 ,得到了当初始能量为正但有上界时解的爆破性条件     

一类具边界耗散的高阶非线性双曲方程整体解的不存在性

本文利用广义凸性方法证明了边界耗散的非线性四阶方程初边值问题整体解的不存在性     

一类半线性椭圆型方程爆炸解的存在性与渐近行为

设Ω是Ｒ＾Ｎ（Ｎ≥２）中的Ｃ＾２有界区域,对非线性项带有适当的梯度与无界系数ｋ（ｘ）,首先应用非线性变换将爆炸解问题,转化成等价的带奇异项的Ｄｉｒｉｃｈｌｅｔ问题,应用极大值原理得到爆炸解问题的最小爆炸速度。随后,应用摄动方法,结合上下解方法与椭圆型方程的估计理论得到了爆炸解的存在性。     

一类非线性广义Euler-Poisson-Darboux方程整体解的渐近性质

J. L Lions and W. A. Stranss [1] have proved the existence of a global solution of the initial boundary value problem for nonlinear generalized Euler-Possion-Darboux equation. In this paper we are going to investigate the asymptotic behavior of the global solution by a difference inequality.     

Blowup and Asymptotic Behavior of a Free Boundary Problem with a Nonlinear Memory

In this paper, we investigate a reaction-diffusion equation $u_t-du_{xx}=au+\int_{0}^{t}u^p(x,\tau){\rm d}\tau+k(x)$ with double free boundaries. We study blowup phenomena in finite time and asymptotic behavior of time-global solutions. Our results show if $\int_{-h_0}^{h_0}k(x)\psi_1 {\rm d}x$ is large enough, then the blowup occurs. Meanwhile we also prove when $T^*<+\infty$, the solution must blow up in finite time. On the other hand, we prove that the solution decays at an exponential rate and the two free boundaries converge to a finite limit provided the initial datum is small sufficiently.     

一类非线性波方程整体解的存在性和不存在性

This paper deals with the existence and uniqueness of the global solution of the initial boundary value problem of a class of wave equation. In the meantime, it gives the sufficient conditions of blow-up of the solution for the problem in finite time.     

一类双退化非线性抛物型方程

In this paper we study the decay estimate of global solutions to the initialboundary value problem for double degenerate nonlinear parabolic equation by using a difference inequality.     

Blowup,Global Fast and Slow Solutions for a Semilinear Combustible System

In this paper, we investigate a semilinear combustible system $u_t-du_{xx}=v^p, v_t-dv_{xx}=u^q$ with double fronts free boundary, where p ≥ 1, q ≥ 1. For such a problem, we use the contraction mapping theorem to prove the local existence and uniqueness of the solution. Also we study the blowup and global existence property of the solution. Our results show that when pq › 1 blowup occurs if the initial datum is large enough and the solution is global and slow, whose decay rate is at most polynomial if the initial value is suitably large, while when p › 1, q › 1 there is a global and fast solution, which decays uniformly at an exponential rate if the initial datum is small.     

一类二阶非线性阻尼微分方程解的渐近性质

研究了一类二阶非线性阻尼微分方程非振动解的渐近性质,建立了三个渐近性定理.     

一类非线性发展方程整体弱解的存在性和稳定性

该文考虑一类新的非线性方程(｜ut｜r-2ut)t-Δutt-Δu-ρ(t)Δut=f(u) 的初边值问题，利用小扰动法证明了整体弱解的 存在性，借用位势井的概念得到了解的稳定性.〖HT5”H〗关键词:〖HT5”SS〗非线性发展方程;初边值问题;整体弱解;稳定性.     

Complicated Asymptotic Behavior of Solutions for the Cauchy Problem of Doubly Nonlinear Diffusion Equation

In this paper, we analyze the large time behavior of nonnegative solutions to the doubly nonlinear diffusion equation $$u_t−{\rm div}(|∇u^m|^{p−2}∇u^m)=0$$ in $\mathbb{R}^N$ with $p>1,$ $m>0$ and $m(p−1)−1>0.$ By using the finite propagation property and the $L^1-L^∞$ smoothing effect, we find that the complicated asymptotic behavior of the rescaled solutions $t^{\mu/2}u(t^{β_·},t)$ for $0<\mu<2N/(N[m(p−1)−1]+p)$ and $β>(2−\mu[m(p−1)−1])/(2p)$ can take place.     

三阶非线性时滞差分方程解的渐近性

研究了一类三阶非线性变滞量差分方程解的渐近性,给出了该类方程的非振动解当n→+∞时渐近趋于零或趋于某有限数值的几个充分条件.     

一类二阶非线性差分方程解的渐近性质

研究了一类二阶非线性差分方程解的渐近性质,应用分析方法,建立了两个新的渐近性定理.