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。     

一类线性积分方程解的存在唯一性

在这篇文章内我们证明了一类线性积分方程存在唯一解．并给出解的表示式．它以Ｆｒｅｄｈｏｌｍ方程和Ｖｏｌｔｅｒｒａ方程为特殊情形．     

二维趋化N-S方程解的唯一性准则

本文研究一类二维趋化N-S方程解的唯一性问题.利用Littlewood-Paley理论和Besov空间理论以及做差法,获得这一类二维趋化N-S方程弱解唯一性的唯一性准则.     

随机微分—积分方程解的存在唯一性

本文讨论Ｈｉｌｅｒｔ空间中非线性随机微分－积分方程解的存在性,唯一性,在我们所 一组条件下,得到了解的局部存在唯一性的结果。     

半线性随机发展方程解的局部存在唯一性

本文考虑如下Ｈｉｌｂｅｒｔ空间中半线性随机发展方程的Ｃａｕｃｈｙ问题｛ｄｙ（ｔ）＝「Ａｙ（ｔ）＋ｆ（ｔ，ｙ（ｔ））」ｄｔ＋Ｇ（ｔ，ｙ（ｔ）０ｄｗ（ｔ）ｙ（０）＝ｙ０，运用抽象空间压缩映象原理，在两组不同条件下，分别得到了该问题适度解的局部存     

非线性Kawahara方程解的存在唯一性

非线性Kawahara方程是描述不同介质中存在单色非线性扰动时长波的传播问题的一类重要物理模型.本文通过对相应线性问题基本解的估计,导出了一类一般的Strichartz-型光滑时空混合范数估计,进而得到了非线性Kawahara方程解的存在唯一性结果.     

抛物型方程非线性源项的一个反问题

应用Ｓｏｂｏｌｅｖ 紧嵌入定理和积分估计技巧,构造迭代序列证明了非线性源项在Ｈ氹ｌｄｅｒ空间上的局部存在性     

非线性波动方程解的存在性与唯一性

本文在弱解的意义下,证明了具有不连续和非Lipschitz右端的一维波动方程解的存在性与唯一性定理。     

非线性Kawahara方程解的存在唯一性

非线性Ｋａｗａｈａｒａ方程是描述不同介质中存在单色非线性扰动时长波的传播问题的一类重要物理模型．本文通过对相应线性问题基本解的估计,导出了一类一般的Ｓｔｒｉｃｈａｒｔｚ－型光滑时空混合范数估计,进而得到了非线性Ｋａｗａｈａｒａ方程解的存在唯一性结果．     

Koiter壳动力学方程解的存在性和唯一性

用Galerkin方法研究了Koiter壳动力学方程,得到了解的存在性与唯一性结果。     

Existence of Entropy Solutions to Two-Dimensional Steady Exothermically Reacting Euler Equations

We are concerned with the global existence of entropy solutions of the two-dimensional steady Euler equations for an ideal gas, which undergoes a one-step exothermic chemical reaction under the Arrhenius-type kinetics. The reaction rate function ?(T) is assumed to have a positive lower bound. We first consider the Cauchy problem (the initial value problem), that is, seek a supersonic downstream reacting flow when the incoming flow is supersonic, and establish the global existence of entropy solutions when the total variation of the initial data is sufficiently small. Then we analyze the problem of steady supersonic, exothermically reacting Euler flow past a Lipschitz wedge, generating an additional detonation wave attached to the wedge vertex, which can be then formulated as an initial-boundary value problem. We establish the global existence of entropy solutions containing the additional detonation wave (weak or strong, determined by the wedge angle at the wedge vertex) when the total variation of both the slope of the wedge boundary and the incoming flow is suitably small. The downstream asymptotic behavior of the global solutions is also obtained.     

A Remark on Global Existence,Uniqueness and Exp onential Stability of Solutions for the 1D Navier-Stokes-Korteweg Equations

In this paper, we investigate non-isothermal one-dimensional model of capillary compressible fluids as derived by M Slemrod(1984) and J E Dunn and J Serrin(1985). We establish the existence, uniqueness and exponential stability of global solutions in H~2×H~1× H~1 for the one-dimensional Navier-Stokes-Korteweg equations by a priori estimates,which implies the existence and exponential stability of the nonlinear C_0-semigroups S(t) on H~2× H~1× H~1.     

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.     

Geodesic Webs on a Two-Dimensional Manifold and Euler Equations

We prove that any planar 4-web defines a unique projective structure in the plane in such a way that the leaves of the web foliations are geodesics of this projective structure. We also find conditions for the projective structure mentioned above to contain an affine symmetric connection, and conditions for a planar 4-web to be equivalent to a geodesic 4-web on an affine symmetric surface. Similar results are obtained for planar d-webs, d>4, provided that additional d−4 second-order invariants vanish.     

A Remark on the Existence of Solutions to Nonlinear Equations with Degenerate Mappings

The paper studies nonlinear mappings using methods of p-regularity theory and some concepts and technics of set-valued analysis. The main result addresses to the problem of existence of solutions to nonlinear equations in the degenerate case where a linear part may be singular at the considered initial point.      

Mixed Stochastic Differential Equations: Existence and Uniqueness Result

In this paper we establish an existence and uniqueness result for solutions of multidimensional, time-dependent, stochastic differential equations driven simultaneously by a multidimensional fractional Brownian motion with Hurst parameter \(H>1/2\) and a multidimensional standard Brownian motion under a weaker condition than the Lipschitz one.     

The Blow-up of Solutions for Two-Dimensional Irrotational Compressible Euler Equations

For two-dimensional irrotational compressible Euler equations with initial data where that is a small perturbation from a constant state, we prove that the first-order derivatives of ρ, υ blow-up at the blow-up time, while ρ, υ remain continuous. In particular, in the irrotational case we prove S. Alinhac's statement. Project supported bythe Tianyuan Foundation of China and Lab. of Math. for Nonlinear Problems. Fudan. Univ.     

微分方程解的存在与惟一性的一种证明

运用Banach压缩定理可证明微分方程解的存在与惟一性.