p-调和逼近方法和可控增长条件下能量极小p-调和映射的最优内部正则性

考虑能量极小p-调和映射的弱解在可控增长条件下的部分正则性, 结合pp-调和逼近引理和Tan及Yan 在处理退缩椭圆方程组和障碍问题中得到decay估计的方法得到了弱解的部分正则性，并且得到的正则性结果中的指标是最优的.     

三维Boussinesq方程的正则性准则(英文)

本文研究了三维Boussinesq方程弱解的正则性.利用精细的能量估计方法,得到了关于弱解正则性的一些充分条件,同时这些结果表明速度场比温度函数对于解的正则性起着更重要的作用.     

A-调和方程组的部分正则性和拟正则映射

本文对一类被称为Ａ调和的非线性椭圆型方程组的弱解建立了部分正则性；并且通过将这结果应用到具有连续Ｂｅｌｔｒａｍｉ系数的拟正则映射上，得到了其整体Ｈｌｄｅｒ连续性     

带位势Landau-Lifshitz方程弱解的部分正则性

证明了三维或四维空间中带位势的Landau-Lifshitz方程的稳态解的部分正则性. 众所周知, 由于方法的限制, 对带位势的Landau-Lifshitz方程的稳态弱解的部分正则性需要对位势限制很强的条件. 由位势引起的主要困难是如何得到Scaling函数满足的方程, 这使得Blow-up方法失效. 作者通过直接估计Morrey能量以避开Blow-up方法而克服了该困难.     

一类具p(·,·)结构和L1源的非线性抛物方程解的存在性

该文主要证明了一类具变指数的抛物方程解的存在性结果.虽然源项的可积性不高,但是,零阶项产生的正则化效应帮助得到了L^∞估计.通过选取合适的检验函数,得到了逼近解序列{u^ε}_ε必要的先验估计.运用Young测度方法,确定了非线性项的弱收敛元.     

带有临界型非线性项的强阻尼波动方程北大核心CSCD

研究一类带有临界型非线性项的强阻尼波动方程.通过选择合适的状态空间,证明了算子矩阵[OA-IηAθ]的扇形性,评估了带有临界型增长指数的非线性项的临界性,并且研究了弱解的局部与整体存在性和正则性.     

一个四阶抛物方程整体弱解的正则性

本文研究一个四阶抛物方程的非负大初值混合Dirichlet-Neumann边值问题.使用半离散化解的精细熵估计与插值技巧,得到了正则性更好的整体弱解.     

带有临界型非线性项的强阻尼波动方程

研究一类带有临界型非线性项的强阻尼波动方程.通过选择合适的状态空间,证明了算子矩阵[OA-IηAθ]的扇形性,评估了带有临界型增长指数的非线性项的临界性,并且研究了弱解的局部与整体存在性和正则性.     

三维非匀质Navier-Stokes方程的部分正则性

本文首先引进非匀质Navier-Stokes方程恰当弱解的概念.当初始密度接近正常数的情形时,通过结合局部能量不等式、Sobolev嵌入、压力估计和blow up分析技术,本文建立了恰当弱解的内部正则性准则.最后利用内部正则性准则证明了恰当弱解可能奇异点集的一维Hausdorff测度为零.     

一类退化半导体方程弱解存在性的研究

文章研究了当■(s)=sm(m>1),b(s)=s2和初值为u0,v0∈L 2(Ω)时一类退化半导体方程弱解的存在性．文章首先将原问题正则化,然后对正则化问题在L 2(Ω)空间上做出了有界估计,最后利用收敛性得到了问题的结论．     

The method of p-harmonic approximation and optimal interior partial regularity for energy minimizing p-harmonic maps under the controllable growth condition

In this paper, we are concerned with the partial regularity for the weak solutions of energy minimizing p-harmonic maps under the controllable growth condition. We get the interior partial regularity by the p-harmonic approximation method together with the technique used to get the decay estimation on some Degenerate elliptic equations and the obstacle problem by Tan and Yan. In particular, we directly get the optimal regularity.     

Partial regularity of suitable weak solutions to the incompressible magnetohydrodynamic equations

In this paper, we study the local behavior of the solutions to the three-dimensional magnetohydrodynamic equations. we are interested in both the uniform gradient estimates for smooth solutions and regularity of weak solutions. It is shown that, in some neighborhood of (x₀,t₀), the gradients of the velocity field u and the magnetic field B are locally uniformly bounded in L^∞ norm as long as that either the scaled local L²-norm of the gradient or the scaled local total energy of the velocity field is small, and the scaled local total energy of the magnetic field is uniformly bounded. These estimates indicate that the velocity field plays a more dominant role than that of the magnetic field in the regularity theory. As an immediately corollary we can derive an estimates of Hausdorff dimension on the possible singular set of a suitable weak solution as in the case of pure fluid. Various partial regularity results are obtained as consequences of our blow-up estimates.     

The method of p -harmonic approximation and optimal interior partial regularity for energy minimizing p -harmonic maps under the controllable growth condition

In this paper, we are concerned with the partial regularity for the weak solutions of energy minimizing p-harmonic maps under the controllable growth condition. We get the interior partial regularity by the p-harmonic approximation method together with the technique used to get the decay estimation on some Degenerate elliptic equations and the obstacle problem by Tan and Yan. In particular, we directly get the optimal regularity. This work was partially supported by the National Natural Science Foundation of China (Grant No. 10531020) and the Program of 985 Innovation Engineering on Information in Xiamen University (2004–2007).     

Partial regularity of suitable weak solutions to the four‐dimensional incompressible magneto‐hydrodynamic equations

In this paper, we study the partial regularity of suitable weak solutions to the incompressible magneto‐hydrodynamic equations in dimension four by borrowing and improving the arguments given by Caffarelli, Kohn, and Nirenberg for incompressible Navier–Stokes equations. The so‐called ε‐regularity criteria are established for suitable weak solutions. As an application, an estimate on Hausdorff dimension of the possible singular points set for a suitable weak solution is given. Finally, we present further information on distribution of the possible singular points if the given initial data decay sufficiently rapidly or are not too singular at the origin, in some sense. Copyright © 2012 John Wiley & Sons, Ltd.     

Interior regularity of weak solutions to the perturbed Navier-Stokes equations

In this paper we establish interior regularity for weak solutions and partial regularity for suitable weak solutions of the perturbed Navier-Stokes system, which can be regarded as generalizations of the results in L. Caffarelli, R. Kohn, L. Nirenberg: Partial regularity of suitable weak solutions of the Navier-Stokes equations, Commun. Pure. Appl. Math. 35 (1982), 771–831, and S. Takahashi, On interior regularity criteria for weak solutions of the Navier-Stokes equations, Manuscr. Math. 69 (1990), 237–254.     

Partial regularity for the Navier-Stokes-Fourier system

This paper addresses a nonstationary flow of heat-conductive incompressible Newtonian fluid with temperature-dependent viscosity coupled with linear heat transfer with advection and a viscous heat source term, under Navier/Dirichlet boundary conditions. The partial regularity for the velocity of the fluid is proved for each proper weak solution, that is, for such weak solutions which satisfy some local energy estimates in a similar way to the suitable weak solutions of the Navier-Stokes system. Finally, we study the nature of the set of points in space and time upon which proper weak solutions could be singular.     

具有Dini连续性系数的非线性椭圆方程组在自然增长条件下的最优内部部分正则性

本文我们研究的是具有Dini连续性系数的散度形式的非线性椭圆方程组在自然增长条件下的问题．我们证明所用的方法是有Dugaar和Grotowski所引进的调和逼近技巧。这种技窍在证明弱解的局部正则性时非常重要．我们可以用之直接得到最优局部正则性结果．     

Remarks on partial regularity for suitable weak solutions of the incompressible magnetohydrodynamic equations

In this paper, we are concerned with the partial regularity for suitable weak solutions of the tri-dimensional magnetohydrodynamic equations. With the help of the De Giorgi iteration method, we obtain the results proved by He and Xin (C. He, Z. Xin, Partial regularity of suitable weak solutions to the incompressible magnetohydrodynamic equations, J. Funct. Anal. 227 (2005) 113–152), namely, the one dimensional parabolic Hausdorff measure of the possible singular points of the velocity field and the magnetic field is zero.     

Partial regularity of weak solutions for Landau-Lifshitz system with potential

In this note, we prove the partial regularity of stationary weak solutions for the Landau-Lifshitz system with general potential in four or three dimensional space. As well known, in general, since the constraint of the methods, in order to get the partial regularity of stationary weak solution of the Landau-Lifshitz system with potential, we need to add some very strongly conditions on the potential. The main difficulty caused by potential is how to find the equation satisfied by the scaling function, which breaks down the blow-up processing. We estimate directly Morrey’s energy to avoid the difficulties by blowing up. This work was supported by National Natural Science Foundation of China (Grant Nos. 10631020, 60850005) and the Natural Science Foundation of Zhejiang Province (Grant No. D7080080)     

Local boundedness of solutions to quasilinear elliptic systems

The mathematical analysis to achieve everywhere regularity in the interior of weak solutions to nonlinear elliptic systems usually starts from their local boundedness. Having in mind De Giorgi’s counterexamples, some structure conditions must be imposed to treat systems of partial differential equations. On the contrary, in the scalar case of a general elliptic single equation a well established theory of regularity exists. In this paper we propose a unified approach to local boundedness of weak solutions to a class of quasilinear elliptic systems, with a structure condition inspired by Ladyzhenskaya–Ural’tseva’s work for linear systems, as well as valid for the general scalar case. Our growth assumptions on the nonlinear quantities involved are new and general enough to include anisotropic systems with sharp exponents and the p, q-growth case.