积分元

To simplify the convenient method of the translation of double intergral and based the translation of definite integral and relevant knowledge of double integral , a simple and convenient method is introduced.

为简化二重积分换元公式的推导，利用定积分的换元法及二重积分的有关知识，提出了一种简便的推导方法

To simplify the detrusion of the double integral exchange formula,a simple method is derived after using the recevant knowledge of the methed of substitution in definite integral and double integral.

为简化二重积分换元公式的推导，利用定积分的换元法及二重积分的有关知识，提出了一种简便的推导方法。

The subsection integral is used to get a simple function at first in the numerical calculation, and boundary integral is realized by gauss integral on each panel and line, then the complexity and isstability as a result of the high frequency surge function can be avoided.

数值计算中，首先采用分部积分对被积函数进行简化处理，然后采用高斯积分实现面元和线元上的积分，避免了被积函数为高频振荡函数所带来的数值计算的复杂性和不确定性。

In sphere approximate, GPS/Gravity-BVP is Neumann problem over exterior spherical domains. Then the natural boundary reduction, suggested by Feng and Yu, is applied to deal with the three dimensional problems. By expansion in spherical harmonics, the natural integral equations of harmonic problems over exterior spherical domains are obtained. Meanwhile, a numerical method for solving geodetic BVP is developed.

在球近似下将GPS-边值问题转化为Neumann外问题，用自然边界元法进行自然边界归化，得到自然边界积分方程，再求自然边界积分方程的数值解，与其他边界元方法相比，自然边界元法的计算量大大减小，并且具有很好的逼近性质，能有效地处理奇异积分，是求解GPS-边值问题有效方法。

Indefinite integral concept,, indefinite integral nature of the basic integral formula, the indefinite integral proofs, indefinite integral substitution integration, integration by parts, the indefinite integral rational function integral.

不定积分概念，，不定积分性质，基本积分公式，不定积分证明方法，不定积分换元积分法，分部积分法，不定积分有理函数积分。

Indefinite integral concept,, indefinite integral nature of the basic integral formula, the indefinite integral proofs, indefinite integral substitution integration, integration by parts, the indefinite integral rational functions.

不定积分概念，，不定积分性质，基本积分公式，不定积分证明方法，不定积分换元积分法，分部积分法，不定积分有理函数积分。

Aimed at increasing the accuracy and speed of BEM, meanwhile decreasing taken up memory, this dissertation has studied singular integrals and nearly singular integrals of BEM, surface BEM character and multipole BEM delaminating and storing technology, and put forward high precision fast BEM. And appling this method the electric potential and electric field intensities distribution of the UHV insulators are calculated preliminarily.

本论文以提高边界元的精度和计算速度，降低计算机内存占用为目标，研究了边界元的奇异积分和接近奇异积分计算方法、曲面边界元特性以及多极子边界元分层和存储技术，提出了高精度快速边界元法，并运用该方法初步计算了特高压绝缘子上电位和电场强度分布。

Aimed at increasing the accuracy and speed of BEM , meanwhile decreasing taken up memory, this dissertation has studied singular integrals and nearly singular integrals of BEM , surface BEM character and multipole BEM delaminating .

本论文以提高边界元的精度和计算速度，降低计算机内存占用为目标，研究了边界元的奇异积分和接近奇异积分计算方法、曲面边界元特性以及多极子边界元分层和存储技术，提出了高精度快速边界元法，并运用该方法初步计算了特高压绝缘子上电位和电场强度分布。

In order to test the feasibility of spectral element methods, time integral methods and absorbing boundary conditions for aeroacoustics, several programs based of Microsoft Visual C++ are presented for different time integral methods and boundary consitions.

为验证本文的谱元方法、时间积分方法和吸收边界条件对于求解气动声学问题的可行性，本文基于Microsoft Visual C++平台编制了分别采用不同时间积分方法和边界条件的谱元算法程序，计算结果证明了谱元方法的高精度以及两种时间积分方法的可行性。

In the new method for two-dimensional problems the line integrals onboundary elements are converted into the evaluation of potentialfunctions at the ends of these elements.For three-dimensional cases,thesurface integrals on the usual boundary elements are transformed,through an application of Stokes'theorem,into line integrals on thebounding contours of these elements.

边界轮廓法是刚刚出现的一种新型的边界元法，该方法的核心是利用边界积分方程被积函数散度为零的特性，对二维问题，原积分方程中沿边界单元的线积分被化为单元两端点势函数之差计算，对三维问题，将边界单元上的面积分转变为沿单元轮廓的线积分，它是一种十分简便有效的边界元新技术。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。