The Existence of Weak Solutions to the 2D Euler Equations with Initial Vorticity in BMO

We shall prove that there exists a weak solution to the 2D Euler equations with initial vorticity in BMO and initial velocity in L^∞.     

Continuity of Weak Solutions for Quasilinear Parabolic Equations with Strong Degeneracy

The aim of this paper is to study the continuity of weak solutions for quasilinear degenerate parabolic equations of the form U_t-Δφ(u)=O, whereφ■C~1(R~1)is a strictly monotone increasing function.Clearly,the above equation has strong degeneracy,i.e.,the set of zero points ofφ′(·)is permitted to have zero measure. This is an answer to an open problem in[13,p.288].     

初始旋度ω0∈L（logL）^α（α〉1／2）的2—D Euler方程弱解的存在性

本文证明了当初始旋度ω０∈Ｌ（ｌｏｇＬ）＾α∩Ｌ＾α〉１／２时二维无粘Ｅｕｌｅｒ方程柯西问题的整体解的存在性，其中Ｌ（ｌｏｇＬ）＾α是Ｚｙｇｍｕｎｄ函数类，在有界区域，它包含任意的Ｌ＾ｐ∩Ｌ＾１空间。     

Energy Equality and Uniqueness of Weak Solutions to MHD Equations in L∞（0, T; L^n（Ω））

In this paper, we study the energy equality and the uniqueness of weak solutions to the MHD equations in the critical space L∞（0, T; L^n（Ω）. We prove that if the velocity u belongs to the critical space L∞（0, T; L^n（Ω）, the energy equality holds. On the basis of the energy equality, we further prove that the weak solution to the MHD equations is unique.     

Existence and Nonuniqueness of Weak Solutions of the Initial-Boundary Value Problem for ut=u^σ div（｜△↓u｜^（p-2）△↓u）

In this paper, we study the existence and nonuniqueness of weak solutions of the initial and boundary value problem for ut =u^σ div(|△↓u|^(p-2)△↓u) with σ≥1. Localization property of weak solutions is also discussed.     

Global Weak Solutions of Initial Boundary Value Problem for Boltzmann－Poisson System with Absorbing Boundary

This paper deals with the initial boundary value problem for the Boltzmann-Poisson system, which arises in semiconductor physics, with absorbing boundary. The global existence of weak solutions is proved by using the stability of velocity averages and the compactness results on L1-theory under weaker conditons on initial boundary values.     

Global Existence and Blow-up of Solutions to Multi-dimensional （n ≤ 5） Viscous Cahn-Hilliard Equation

In this paper we consider the viscous Cahn-Hilliard equation with spatial dimension n ≤5, and established global existence of weak solutions for small initial value and blow-up of solutions for any nontrivial initial data.     

Existence and Asymptotic Behavior of Radially Symmetric Solutions to a Semilinear Hyperbolic System in Odd Space Dimensions

This paper is concerned with a class of semilinear hyperbolic systems in odd space dimensions. Our main aim is to prove the existence of a small amplitude solution which is asymptotic to the free solution as t→-∞in the energy norm, and to show it has a free profile as t→ ∞. Our approach is based on the work of [11]. Namely we use a weighted L∞norm to get suitable a priori estimates. This can be done by restricting our attention to radially symmetric solutions. Corresponding initial value problem is also considered in an analogous framework. Besides, we give an extended result of [14] for three space dimensional case in Section 5, which is prepared independently of the other parts of the paper.     

Solutions and Multiple Solutions for p（x）-Laplacian Equations with Nonlinear Boundary Condition

The authors study the p（x）-Laplacian equations with nonlinear boundary condition. By using the variational method, under appropriate assumptions on the perturbation terms f1 （x, u）, f2（x, u） and h1（x）, h2（x）, such that the associated functional satisfies the ＂mountain pass lemma＂ and ＂fountain theorem＂ respectively, the existence and multiplicity of solutions are obtained. The discussion is based on the theory of variable exponent Lebesgue and Sobolev spaces.     

The Existence of Solutions of （k, n - k） Conjugate Boundary Value Problems in Banach Spaces

In this paper,by use of the Schauder fixed-point theorem,the existence of solution of (k,n-k) Conjugate boundary value problems in Banach spaces is investigated.     

有关二维Euler方程的一些估计

首先得到Ｌｏｒｅｎｔｚ空间中的一些结果,然后在此基础上得到了有关二维Ｅｕｌｅｒ方程解的一些估计。这些估计与该方程当初始旋度ω０∈Ｌ＾－１∩Ｌ＾ｐ（ｐ〉１）时解的唯一性有关。     

Existence of Solutions for Three Dimensional Stationary Incompressible Euler Equations with Nonvanishing Vorticity

In this paper, solutions with nonvanishing vorticity are established for the three dimensional stationary incompressible Euler equations on simply connected bounded three dimensional domains with smooth boundary. A class of additional boundary conditions for the vorticities are identified so that the solution is unique and stable.     

Navier-Stokes方程恰当弱解的存在性

本文假定外力f(x,t)∈Ｌ^1(0,T;L^2(Ω）,初始速度u0∈Ｈ,证明了三维Ｎavier-Stokes方程恰当弱解的存在性。     

非线性椭圆型偏微分方程弱解的存在性

在W1,p(x)空间框架下研究了具有p(x)增长条件的椭圆型偏微分方程:-d iva(x,u,D u) g(x,u,u)=f,得到了在W10,p(x)空间中弱解的存在性,推广了Boccardo等关于在Sobo lev空间中弱解的相应结论.     

二维Stokes近似系统弱解的全局存在性

本文主要考虑了二维可压流体的Stokes近似系统,我们运用类似于Eduard Feireisl的方法证明了Stokes近似系统在,γ=1与γ>1时弱解的全局存在性.     

一类退化的Davey-Stewartson方程组弱解的存在性

本文主要考虑的是一类退化的Davey -Stewartson方程 ,证明了此方程组弱解的存在性 .     

二维等熵可压欧拉方程古典解的存在性(英文)

研究二维等熵可压缩欧拉方程的古典解存在性.利用迭代技巧,得到解的局部存在性及唯一性,并且还证明了解在有限时间内爆破,即可压缩欧拉方程不存在全局古典解.     

三维可压等熵Euler方程光滑解的整体存在性

研究了三维可压等熵Euler方程Cauchy问题光滑解的整体存在性.如果初值是一个常状态的小扰动并且初速度的旋度等于零,证明了三维可压等熵Euler方程Cauchy问题光滑解的整体存在性.