算子方程

Different from the scattering theory used in the derivation of conventional generalized screen propagator, in this paper, a high order formula of generalized screen propagator for oneway wave equation is proposed by using the asymptotic expansion of singlesquareroot operator.

不同于常规广义屏传播算子的推导中使用散射理论，本文利用单平方根算子的渐近展开，推导出了单程波方程广义屏传播算子的高阶表达式。

The stable wave-field propagators of one-way wave equation for Born and Rytov approximations are derived by using the local Born and local Rytov approximation methods in the scatter theory of wave-field propagation, and their application effects in prestack depth migration imaging of wave equation are compared theor...

利用波场传播散射理论中的局部Born近似和局部Rytov近似，分别导出了单程波方程的稳定的Born近似波场传播算子和稳定的Rytov近似波场传播算子，然后从理论和实践上比较了它们在地震数据波动方程叠前深度偏移成像中的应用效果。

Transforming the boundary value problem with p-Laplace operator into operator equation, giving propriety conditions for different value of p,and using an extension of Mawhin s continuation theorem,the existence of solution of a boundary value problem with p-Laplace operator is proved, and the sufficient conditions for solution existence are obtained.

将具p-Laplace算子的边值问题转化成算子方程，对于p的不同取值给出适当的条件。利用Mawhin连续引理的推广形式，证明了一类具p-Laplace算子的微分方程边值问题解的存在性，得到了一系列解存在的充分条件

In the second chapter, the KDV type equation on unbounded domain is considered. Applying with the method of decomposing operator and the theory of constructing some compact operator in weighted space, the existence of exponential attractor is obtained.

在第二章中，运用带权空间构造一类紧算子和算子分解的方法，研究了无界区域上的KDV型方程，得到了该方程指数吸引子的存在性。

Aimed to the differential equation in form of convolution and the functional presented by M. E. Gurtin, the matrix operator which includes the differential equation and the boundary condition is proved self-adjoint, furthermore a general variational principles in form of convolution and the preparation theorem are given and proved.

针对M.E.Gurtin提出的含卷积运算的抛物型偏微分方程及其对应的泛函，运用泛函势算子理论，从理论上证明了含卷积运算的抛物型偏微分方程及其边界条件所对应的矩阵算子有势，进而给出并证明了具有普适意义的含卷积运算的变分定理及预备定理。

Chapter 4 presents detailed analysis of Whitney-type hexahedron and prism using differential form.

第2章介绍微分形式中几个常用典型算子的性质，包括微分算子、外积和Hodge星算子；给出了微分形式对电磁学物理量的分类及Maxwell方程的微分形式。

In the last chap-ter,the natural integral equation and natural boundary element method forharmonic problem on exterior elliptic domain are introduced.Then,based onthis,the natural boundary reduction method for a kind of exterior problem ofanisotropic constant coefficients elliptic equation is discussed, the natural inte-gral equation and its solving method on circular boundary and elliptic bound-ary are obtained.These results can be directly applied in coupled methodand DDM for exterior boundary value problem.

最后，讨论了椭圆外区域调和问题的自然积分算子即D-N算子及自然边界元方法，并基于此研究了一类各向异性常系数椭圆型方程外问题的自然边界归化方法，首次得到其在圆周边界及椭圆边界上的自然积分方程及其求解方法，并将这些结果直接应用于外边值问题的耦合算法。

The method is convenient to be used, especially to nonhomogeneous equations and nonhomogeneous boundary value problem.

用微分算子法给出了线性扩散方程和波动方程的通解及初值以及边值相关问题的算子解，特别是对非齐次方程和非齐次边界问题处理尤其简捷适用。

By introducing the general notion of nonwandering operator semigroup T and utilizing a basic result in normed linear space,the nonwandering property of T=e~ is investigated with the constructive method.

通过给出一般算子半群T的非游荡性概念，利用赋范空间的一个基本结果和直接的构造法证明了具有变系数的线性发展方程的强连续解半群T=etA在适当的条件下是非游荡的；另外，通过对C-半群T概念的引进，定义了一个无界算子半群etA，进一步证明了这二者关于非游荡性的联系；最后给出了一个无界算子半群etP关于非游荡性理论的刻画，其中P是微分多项式。

After the brief retrospect of spectral methods applied to get the numerical solutions of partial differential equations, the Walsh spectral methods are extensively studied. A new method of designing the "derivate operator" and a new Walsh spectral method based on quasi-Walsh order are proposed, which primarily prove the special uses of it.

回顾了数值求解偏微分方程的谱方法，比较深入地考察了数值求解偏微分方程的Walsh谱方法，提出了一种新的设计"求导算子"的方法，基于这样设计出来的"求导算子"，提出了一种新的基于类Walsh序的Walsh函数的Walsh谱方法，初步验证了这种序的特殊价值。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。