查询词典 fold singularity

The mass of a black hole is confined to an infinitely small point at its centre, called a singularity.

黑洞所有的质量都处于其中心一个无穷的小点上，我们叫它"奇点"。

About 15 billion years ago, an infinitely small singularity in the "vacuum" broke into a tremendous explosion all of a sudden.

大约150亿年前，在这个"无"中，一个体积无限小的"奇点"骤然间发生了超级大爆炸。

A time domain singularity extraction technique is presented to calculate singular integrals in time domain electric field integral equation solver.

介绍了一种基于奇异提取技术的时域积分方程中奇异积分的处理方法，在奇异提取过程中，电磁波传播的延迟效应对积分的贡献包含在内。

Firstly, Wavelet-Galerkin algorithm for solving the first kind of singular integral equation with the Hilbert kernel is proposed, we use the characteristic of periodic wavelet on L~2([0,1]) and Hilbert kernel to solve and make stiff matrix lower dimensions and become sparser through thresholding,thus the cost of computation is reduced. Because of the singularity of Hilbert kernel we use Tikhonov regularization method to solve the system of stiff equation. At last the convergence and numerical result of approximate solution are given. Secondly, an approach of regularization based on Fourier is presented for sideways heat equation; we give the theory proof and error estimate.

首先，提出了含Hilbert核的第一类奇异积分方程的小波伽辽金(Wavelet-Galerkin)数值算法，该算法中利用了L~2([0，1])上的周期小波和Hilbert核的特点进行处理，使得刚性矩阵维数降低并且通过阈值使得它更加稀疏，减少了计算量；由于Hilbert核的奇异性，通过Tikhonov正则化方法求解所得到的刚性方程组，给出了收敛性和数值结果；其次，对标准的一维逆热传导方程给出了一种基于Fourier正则化方法，给出了理论证明及其误差估计，解决了文献中算法与理论误差估计的不相匹配的现象，该正则化方法不仅保留了测量数据的部分高频成份，且与文献中的算法具有同样的计算量和误差估计。

By usingthe relation between the Bergman kernel and the Riemann mapping and Plemly for-mulae,the second boundary integral equation about the Bergman kernel is obtained,moreover,the integral kernel is a continuous,without any singularity,parametized Neu-mann kernel.We discuss the case of some symmetric property,and get correspondingresults.

主要利用Bergman核与Riemann映照之间的关系，推导出Bergman核满足带有参数化Neumann核的第二类边界积分方程，积分核是连续的没有任何奇性，并讨论了具有某种对称性质的情形。

In this paper,the singularity in the integrand of electrical field integral equation for 3-dimensional vector fields scattering is first analyzed.

本文研究了电场积分方程中被积函数奇异性的处理方法，特别是三维矢量散射分析中出现的高阶奇异性，给出了两种解决积分方程奇异性的数值方法。

The vector surface integral equation can't be applied to numerical computation directly because its integrands possess the high order singularity.

矢量的面积分方程因其被积函数具有高阶奇异性，不能直接应用於数值计算。

Dept.of Microwave Eng.,UEST of China,Chengdu 610054,ChinaAbstract:In this paper,the singularity in the integrand of electrical field integral equation for 3-dimensional vector fields scattering is first analyzed.

本文研究了电场积分方程中被积函数奇异性的处理方法，特别是三维矢量散射分析中出现的高阶奇异性，给出了两种解决积分方程奇异性的数值方法。

Pointing out that the singularity revealed the defects of the general relativity in theory and was not the intrinsic property in the nature world.

而通常所说的光速不变原理，指的是在惯性坐标系或局域惯性坐标系中，真空中的光速各向同性

The authors study the property of the active power/angle sub-matrix in power flow Jacobian matrix and the sufficient condition for the invertibility of the sub-matrix as well as the necessary condition for singularity are given.

探讨了潮流雅可比矩阵中有功/相角子矩阵的性质，给出了该矩阵可逆的充分条件及其奇异的必要条件。

He tendered his resignation to the Prime Minister.

他向首相递了辞呈。不适合

International economy and trade,Nanking 210044

国际经济与贸易，南京 210044