一类一阶常微分方程初值问题的无穷多解性

应用分离变量法,得到了一类一阶微分方程初值问题u′(t)=b(t)f(u(t)),t0,u(0)=0存在无穷多个解的充分必要条件.并给出了全部解.     

常系数非齐次线性微分方程特解的另一种求法

将常系数线性微分方程转化为一阶常系数线性微分方程组,并利用线性微分方程组的基解矩阵的性质和矩阵指数的性质以及非齐次线性微分方程组的常数变易公式,得到了常系数非齐次线性微分方程的积分形式的特解公式,并通过实例说明所得结论的有用性.     

论中值定理类命题证明中的辅助函数构造

借助实例分析的方法,讨论在证明微分与积分相结合的中值定理类命题时,关于辅助函数的构造技巧及其变形思想.     

Subdifferential representation of homogeneous functions and extension of smoothness in Banach spaces

In this paper, we mainly consider proximal subdifferentials of lower semicontinuous functions defined on real Hilbert space and Clarke＇s subdifferentials of locally Lipschitzian functions defined on Banach space respectively, and obtain the generalized Euler identity of homogenous functions. Then, by introducing a multifunction F, we extend the smoothness of sphere and differentiability of norm function in Banach space.     

Large deviation principle for the fourth-order stochastic heat equations with fractional noises

In this paper, we shall study a fourth-order stochastic heat equation driven by a fractional noise, which is fractional in time and white in space. We will discuss the existence and uniqueness of the solution to the equation. Furthermore, the regularity of the solution will be obtained. On the other hand, the large deviation principle for the equation with a small perturbation will be established through developing a classical method.     

Hermitian generalization of the Rarita-Schwinger operators

We introduce two new linear differential operators which are invariant with respect to the unitary group SU（n）. They constitute analogues of the twistor and the Rarita-Schwinger operator in the orthogonal case. The natural setting for doing this is Hermitian Clifford Analysis. Such operators are constructed by twisting the two versions of the Hermitian Dirac operator 6z_ and 6z_ and then projecting on irreducible modules for the unitary group. We then study some properties of their spaces of nullsolutions and we find a formulation of the Hermitian Rarita-Schwinger operators in terms of Hermitian monogenic polynomials.     

关于矩阵函数微分学的一个注记

介绍了以矩阵为变元的函数的微分及其运算法则.与通常的求导运算相比,这里介绍的微分运算理论上更加自然、简洁,使用起来更加容易、更加方便.事实上,矩阵导数应当视为由微分运算派生出来的运算.     

四阶微分方程Hermite有限元的预处理共轭梯度法

对一类四阶微分方程两点边值问题的Hermite有限元方法进行了研究.首先讨论了该方程通常意义下的Galerkin有限元离散,考虑到有限元离散得到的线性方程组的对称正定性,文中采用了预处理最速下降法和共轭梯度方法求解线性方程组,通过选择不同的预处理器,使得求解该方程组的迭代次数有了很大的改观.     

一阶高次齐次微分方程的求解

详细地讨论了一类一阶变系数二次齐次微分方程的特征方程解法,并将其结果推广到同类型的一阶变系数n次齐次微分方程和一阶常系数n次齐次微分方程.     

离散外微分与计算电磁学

计算电磁学的核心之一是数值求解Maxwell方程组.适当的离散方式是保证结果能真实反映物理现象的关键.为了在离散的过程中保持该方程组的几何性质,我们建立了基于棱柱网格的系数为R的格点规范理论,其离散曲率满足相应的Bianchi恒等式.通过适当定义离散微分形式之间的内积和棱柱网格上的Hodge星算子,我们由离散变分导出源方程和连续性方程,和Bianchi恒等式一起称为真空中的离散Maxwell方程组.这组方程是内蕴的,并具有规范不变性.