一类缺乏紧性的拟线性椭圆型方程组多重弱解的存在性

本文在一定条件下讨论了一类被两个p-Laplacian算子控制的拟线性椭圆型方程组Dirichlet问题多重弱解的存在性.     

具有奇异项的拟线性椭圆型方程组无穷多弱解的存在性

本文在一定条件下讨论了一类具有奇异项的,被两个pLaplacian算子控制的拟线性椭圆型方程组Dirichlet问题无穷多弱解的存在性.     

一维双极量子漂移-扩散稳态模型的弱解

本文研究了半导体中一维双极量子漂移-扩散稳态模型的弱解.利用指数变换法把此模型转化成两个四阶椭圆方程,然后利用Schauder不动点定理证明了转化后的方程组弱解的存在性.另外得到了方程组解的唯一性和半古典极限.     

一维双极量子漂移-扩散稳态模型的弱解（英文）

本文研究了半导体中一维双极量子漂移–扩散稳态模型的弱解.利用指数变换法把此模型转化成两个四阶椭圆方程,然后利用Schauder不动点定理证明了转化后的方程组弱解的存在性.另外得到了方程组解的唯一性和半古典极限.     

含Grushin算子的抛物方程拉回吸引子的高阶吸引性

本文考虑了含Grushin算子的非自治抛物方程拉回吸引子的高阶吸引性.我们首先建立了极大值原理,其次研究了弱解差的高阶可积性,最后证明了高阶吸引性.     

具有人为故障的人-机系统的可靠性分析

介绍了一个具有人为故障的人-机系统的可修复模型,利用算子半群理论证明了新模型系统解的存在唯一性和指数型稳定性.另外,当故障率λ_0→∞时,系统的瞬态可用度逼近弱解系统瞬态可用度.即,新模型系统逼近原模型弱解系统.     

自然增长下的具VMO系数拟线性椭圆组的部分正则性

设散度型拟线性系数算子关于自变量x一致满足VMO的结构条件,对于低阶项满足自然增长条件的拟线性椭圆方程组,建立了其弱解具有确切Holder指数的部分正则性.     

微伸缩的热弹性力学方程组柯西问题解的奇性传播

用频率分析对角化的方法,研究了一维线性微伸缩的热弹性力学方程组柯西问题解的奇性传播规律.首先从微局部观点出发,利用拟微分算子将双曲抛物的耦合方程组弱解耦.然后利用经典的双曲抛物方程理论和穿梭法,证明了柯西问题解的奇性传播具有有限传播速度、解的奇性沿双曲算子的零次特征带进行传播.     

热盐环流方程全局弱解的存在性

该文利用T-弱连续算子理论和空间序列方法证明了热盐环流方程全局弱解的存在性.首先根据热盐环流方程的形式选择试探函数空间和解函数空间,再将方程化为抽象的算子方程,验证算子是T-弱连续的并满足对应条件,从而得到热盐环流方程全局弱解的存在性.     

无界区域上p(x)-Laplacian方程组全局弱解的局部W~(2,2)正则性

本文用弱连续法研究p(x)-Laplacian方程组.在一定假设下,我们应用弱连续法证明p(x)-Laplacian方程组在无界区域上全局弱解的存在性,在此基础上,又进一步证明此全局弱解的局部W~(2,2)正则性.     

含参广义集值向量均衡问题有效解映射下半连续的最优条件

在实Hausdorff拓扑向量空间中研究一类含参广义集值向量均衡问题弱有效解与有效解映射的下半连续性. 在近似锥-次类凸的条件下, 运用标量化的方法得到弱有效解的标量化结果. 在适当条件下, 得到含参广义集值向量均衡问题弱有效解与有效解映射下半连续性定理.     

Stability behaviors of Leray weak solutions to the three-dimensional Navier–Stokes equations

This paper is devoted to the investigation of stability behaviors of Leray weak solutions to the three-dimensional Navier–Stokes equations. For a Leray weak solution of the Navier–Stokes equations in a critical Besov space, it is shown that the Leray weak solution is uniformly stable with respect to a small perturbation of initial velocity and external forcing. If the perturbation is not small, the perturbed weak solution converges asymptotically to the original weak solution as the time tends to the infinity. Additionally, an energy equality and weak–strong uniqueness for the three-dimensional Navier–Stokes equations are derived. The findings are mainly based on the estimations of the nonlinear term of the Navier–Stokes equations in a Besov space framework, the use of special test functions and the energy estimate method.     

Existence of solutions for the MHD-Leray-alpha equations and their relations to the MHD equations

In this paper we derive some new equations and we call them MHD-Leray-alpha equations which are similar to the MHD equations. We put forward the concept of weak and strong solutions for the new equations. Whether the 3-dimensional MHD equations have a unique weak solution is unknown, however, there is a unique weak solution for the 3-dimensional MHD-Leray-alpha equations. The global existence of strong solution and the Gevrey class regularity for the new equations are also obtained. Furthermore, we prove that the solutions of the MHD-Leray-alpha equations converge to the solution of the MHD equations in the weak sense as the parameter ε in the new equations converges to zero.     

弱向量变分不等式解集的连通性

研究拓扑向量空间到连续线性映射空间映射的弱向量变分不等式和与之相关 的纯量型变分不等式解集的关系, 引入弱和强一致连续概念,利用纯量型变分不等式 解集所表征的集值映射的特性给出弱向量变分不等式解集连通的一个充分条件。     

D-η-半预不变真拟凸多目标优化的最优性刻画

首先,举例验证了三种D-η-半预不变真拟凸映射的存在性;然后,在D-η-半严格(严格)半预不变真拟凸性下,得出了多目标优化问题的局部有效解为全局有效解,局部弱有效解为全局弱有效解,并举例验证了所得结果;最后,在D-η-严格半预不变真拟凸性下,建立了多目标优化问题的全局弱有效解和局部弱有效解的唯一性的刻画。     

D-η-半预不变真拟凸多目标优化的最优性刻画

首先,举例验证了三种D-η-半预不变真拟凸映射的存在性;然后,在D-η-半严格(严格)半预不变真拟凸性下,得出了多目标优化问题的局部有效解为全局有效解,局部弱有效解为全局弱有效解,并举例验证了所得结果;最后,在D-η-严格半预不变真拟凸性下,建立了多目标优化问题的全局弱有效解和局部弱有效解的唯一性的刻画。     

On the breakdown of a continuous multi-dimensional gasdynamic flow

Summary Starting with the theory of weak discontinuities, an expression for the point at which the solution itself becomes discontinuous is derived. The formula is readily applicable to multidimensional hyperbolic systems, with arbitrary initial data.Detailed application to gasdynamics is given, with explicit results for an atmosphere with exponentially decaying density.

---

Résumé Considérant la propagation des discontinuités faibles dans une solution continue d'un système hyperbolique quasilinéaire, on déduit une formule décrivant l'apparition des discontinuités dans la solution même.On présente une application détaillée à l'aérodynamique, avec un exemple concernant une atmosphère à densité décroissant exponentiellement.

     

<Emphasis Type="Italic">L</Emphasis><Superscript><Emphasis Type="Italic">p</Emphasis></Superscript> estimates and asymptotic behavior of extremal function to Hardy-Sobolev type inequality on the H-type group*

This paper is devoted to discuss the regularity of the weak solution to a class of non-linear equations corresponding to Hardy-Sobolev type inequality on the H-type group. Combining the Serrin's idea and the Moser's iteration, L^p estimates of the weak solution are obtained, which generalize the results of Garofalo and Vassilev in [6, 14]. As an application, asymptotic behavior of the weak solution has been discussed. Finally, doubling property and unique continuation of the weak solution are given. *This material is based upon work funded by Zhejiang Provincial Natural Science Foundation of China under Grant No. Y606144.     

On the finite element approximation of incompressible flows of an electrically conducting fluid

We consider the finite element approximation of incompressible flows field of an electrically conducing fluid in the presence of a magnetic where it is assumed that this field is prescribed. A weak form is chosen that is similar in some respects to a weak form used by many authors for the Navier-Stokes equations. Existence and uniqueness results are presented for the weak problem. A finite element Algorithm is given for the approximate solution of the weak problem and error estimates are derived.