非线性双曲型Schrdinger方程L~2整体解的存在性

本文讨论含L2次临界指数非线性项的广义Schrodinger方程柯西问题,用Strichartz不等式和压缩映射原理证明了在L2初值条件下方程有整体解,即u(t)∈C(R,L2(Rn)),而且证明了含L2临界指数非线性项的广义Schrodinger方程有小初值L2整体解.     

非椭圆非线性Schr(o)dinger方程Hs整体解

对含L2次临界指数非线性项的非椭圆型Schr(o)dinger方程柯西问题进行了讨论,用Strichartz不等式和压缩映像原理证明了方程有Hs局部解,由L2守恒律得到方程的Hs整体解.     

一类非线性Schrdinger方程的整体自相似解

本文应用调和分析的方法研究了一类非线性Schrodinger方程Cauchy问题整体自相似解的存在唯一性．     

一类非线性Schr(o)dinger方程的整体小解

本文研究带有非线性项|u|~pu的高阶非线性Schr(?)dinger方程的Cauchy问题．对于p的某一取值范围。我们证明了此问题整体解的存在唯一性,并得到了解关于初值的连续依赖性及解具有较强的衰减估计。     

具材料阻尼的非线性双曲型方程整体解的不存在性

考虑了一类具材料阻尼的非线性双曲型方程初边值问题整体解的不存在性．分别采用能量方法、Jensen不等式和凹性方法证明了该问题整体解的不存在性定理．作为主要结果的应用,给出了3个例子．     

一类非线性Schr(o)dinger方程的整体自相似解

本文应用调和分析的方法研究了一类非线性Sehrodinger方程Cauchy问题整体自相似解的存在唯—性．     

一类具非齐次项的非线性Schr(o)dinger方程整体解存在的最佳条件

本文讨论具非齐次项的非线性Schrodinger方程.根据基态的特征,运用势井理论和凹方法,我们获得了该方程整体解存在的-个最佳条件,同时也给出了当初值多小时,方程的整体解存在.     

高阶非线性Schr(o)dinger方程的自相似解

研究非线性项的形式为|u|pu,p>0的2m阶非线性Schr(o)dinger方程的自相似解.利用scaling和压缩映象原理证明了当初值满足一定条件时Cauchy问题解的整体存在性,据此给出了当初值的形式为U(x/|x|)|x|-2m/p时,自相似解的存在性.     

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     

一类带调和势的非线性Schr(O)dinger方程在RN中的整体解存在的门槛

本文考虑一类带调和势的非线性Schrodinger方程iψt=-△ψ+|x|2ψ-μ|ψ|p-1ψ-λ|ψ|q-1ψ,x∈RN,t≥0,其中μ＞0,λ＞0.当N=1,2时,1＜p＜q＜∞;当N≥3时,1＜p＜q＜N+2/N-2.运用精巧的变分方法、势井方法和凸方法,得到了方程的整体解和爆破解存在的门槛.进一步回答了:当q＞p＞1+4/N时,方程的Cauchy问题的初值小到什么程度,其整体解存在?.     

多维双极Euler-Poisson方程的C~1解的整体存在性(英文)

本文研究了出现在半导体器件或者等离子中的多维双极Euler-Poisson方程,证明了它的初值问题的C1解在Besov空间的整体存在性,同时也得到了在二维和三维情形下,速度的璇度以指数的速率收敛到零.     

GLOBAL EXISTENCE FOR NONLINEAR PARABOLIC EQUATIONS

This paper is concerned with the global existence of Cauchy problem for nonlinearparabolic equations.The sharp results concerning the space dimension have been obtainedwhich improve the corresponding results obtained by S.Klainerman.     

GLOBAL EXISTENCE AND EXPONENTIAL DECAY OF SOLUTIONS OF GENERALIZED KURAMOTO-SIVASHINSKY EQUATIONS

We study the Dirichlet initial-boundary value problem of the generalized Kuramoto-Sivashinsky equation ut+uxxxx+λuxx+f(u)x=0 on the interval [0,l],The nonlinear function f satisfies the conditon |f′(u)|≤c|u|^α-1 for some α>1. We prove that if λ4π^2/t^2,then the strong solution is global and exponentially decays to zero for and initial datum uo∈H0^2(0,l) if 1<α≤7,and for small u0∈H0^2(0,l)if α>7,We the consider the equation ut+uxxxx+λuzz+μu+auxxx+bux=F(u,ux,uxx,uxxx),We prove that if F is twice differentiable,Δ↓F is Lipschitz continuous,and F(0)=Δ↓F（0)=0,and if λand μsatisfu μ+σ(λ）>0(σ（λ）=the first eigenvalue of the operator d^4/dx^4+λd^2/dx^2),then the solution for small initial datum is global and exponentially decays to zero.     

GLOBAL EXISTENCE AND BLOW-UP OF SOLUTIONS FOR GENERALIZED POCHHAMMER-CHREE EQUATIONS

In this article,we study the initial boundary value problem of generalized Pochhammer-Chree equation u_(tt)-u_(xx)-u_(xxt)-u_(xxtt)=f(u) xx,x ∈Ω,t 0,u(x,0) = u0(x),u t(x,0)=u1(x),x ∈Ω,u(0,t) = u(1,t) = 0,t≥0,where Ω=(0,1).First,we obtain the existence of local W k,p solutions.Then,we prove that,if f(s) ∈ΩC k+1(R) is nondecreasing,f(0) = 0 and |f(u)|≤C1|u| u 0 f(s)ds+C2,u 0(x),u 1(x) ∈ΩW k,p(Ω) ∩ W 1,p 0(Ω),k ≥ 1,1 p ≤∞,then for any T 0 the problem admits a unique solution u(x,t) ∈ W 2,∞(0,T;W k,p(Ω) ∩ W 1,p 0(Ω)).Finally,the finite time blow-up of solutions and global W k,p solution of generalized IMBq equations are discussed.     

EXISTENCE AND UNIQUENESS OF THE GLOBAL L1 SOLUTION OF THE EULER EQUATIONS FOR CHAPLYGIN GAS

In this paper,we establish the global existence and uniqueness of the solution of the Cauchy problem of a one-dimensional compressible isentropic Euler system f...     

GLOBAL EXISTENCE OF THE SOLUTIONS OF NONLINEAR PARABOLIC EQUATIONS IN EXTERIOR DOMAINS

This paper deals with the following IBV problem of nonlinear parabolic equation: $$\[\left\{ {\begin{array}{*{20}{c}} {{u_t} = \Delta u + F(u,{D_x}u,D_x^2u),(t,x) \in {B^ + } \times \Omega ,}\{u(0,x) = \varphi (x),x \in \Omega }\{u{|_{\partial \Omega }} = 0} \end{array}} \right.\]$$ where $\[\Omega \]$ is the exterior domain of a compact set in $\[{R^n}\]$ with smooth boundary and F satisfies $\[\left| {F(\lambda )} \right| = o({\left| \lambda \right|^2})\]$, near $\[\lambda = 0\]$. It is proved that when $\[n \ge 3\]$, under the suitable smoothness and compatibility conditions, the above problem has a unique global smooth solution for small initial data. Moreover, It is also proved that the solution has the decay property $\[{\left\| {u(t)} \right\|_{{L^\infty }(\Omega )}} = o({t^{ - \frac{n}{2}}})\]$, as $\[t \to + \infty \]$.     

SHARP CRITERIONS OF GLOBAL EXISTENCE AND COLLAPSE FOR COUPLED NONLINEAR SCHRODINGER EQUATIONS

In this paper, a series of sharp criterions of global existence and collapse for coupled nonlinear Schr6dinger equations are derived out in terms of the characteristics of the ground state and the local theories. And the conclusion that how small the initial data are, the global solutions exist is proved.     

GLOBAL EXISTENCE OF WEAK SOLUTIONS TO THE THREE-DIMENSIONAL FULL COMPRESSIBLE QUANTUM EQUATIONS

We consider the quantum Navier-Stokes equations for the viscous, compressible, heat conducting fluids on the three-dimensional torus T~3. The model is based on a system which is derived by Jungel, Matthes and Milisic [15]. We made some adjustment about the relation of the viscosities of quantum terms.The viscosities and the heat conductivity coefficient are allowed to depend on the density, and may vanish on the vacuum. By several levels of approximation we prove the global-in-time existence of weak solutions for the large initial data.