积分公式

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。

In this paper the direct boundary integral equation of two-dimensional Laplace equation for Dirichlet problem is considered, which is deduced by Green's formula and the fundamental solution, and is a Fredholm integral equation of the first kind.

本文考虑用Green 公式和基本解推导得出直接边界积分方程来求解二维Laplace 方程的Dirichlet 问题，该直接边界积分方程是第一类Fredholm 积分方程。

Though blocking computing matrix,it can decrease the calculation amount of matrix multiplication.Meanwhile,the different simplified formats are presented when computing Duhamel integration with Trapezium formula、Simpson formula、Cotes formula and Gauss formula.

通过分块计算矩阵，能够减小矩阵乘法的计算量，同时分别给出了利用梯形公式、Simpson公式、Cotes公式、高斯公式计算Duhamel积分时的不同简化格式。

By using this method we obtain two gen-eralized transformation formulae of q-integral form,two identities of basic hypergeometric series,as well as formal extensions for q-Pfaff-Saalschütz formula,q-Chu-Vandermonde identity and a three-term transformation formula of _3φ_2-series.

我们推广了两个q-积分形式的变换公式和两个有关基本超几何级数的恒等式，还得到q-Pfaff-Saalschütz公式、q-Chu-Vandermonde恒等式和基本超几何级数中一个有关_3φ_(2~-)级数的三项变换公式等的形式推广。

Using this formula ,we get several important inference and prove that when the curve and surface integral of the first kind's integrand is odd function or even function and the integral curve or surface is symmetry.

并且利用这个公式，推导出了当第一型曲线积分或曲面积分的被积函数为奇函数或偶函数，积分曲线或曲面是对称的时的几个重要的推论及证明。

In the computation of aerodynamic forces, the present work is based on the work of Morino et al., but the following aspects are improved:(1) In computing the steady transonic aerodynamic load, the steady transonic nonlinear integral equation is solved by relaxation-iteration method in this thesis, instead of solving the time dependent transonic nonlinear integral equation, so that the computing time is saved greatly;(2) The influence coeifficients represented by volume integral are transformed to surface integral by using the Gaussian Theorem, so the analytical form of these coeifficients can be obtained and this leads to be more convenient to analyse and compile computer program;(3) The shock capturing method is used in every time step in present work, no shock moving term is added in the integral equation, so that it is more convenient and simpler to treat.

在气动力计算方面，本文基于Morino等人的工作，作了如下几方面的改进：（1）在计算定常跨音速流场（作为非定常绕流计算的初场）时，本文采用松驰迭代法直接求解跨音速定常非线性积分方程，而不是采用时间相关法求解非定常非线性积分方程，这样大大节省了计算机时；（2）将以体积分形式出现的影响系数化为面积分，并获得解析公式，这样便于分析和编写程序；（3）对运动的激波，本文通过在每一个时间步长上采用激波捕捉法而得到，而不是在积分方程中附加激波运动项，因而处理起来简单方便得多。

The formula was established about calculating design parameters and technological parameters of ideal strip and bent strip in the period of forming. The thesis presented how to calculate the deformed area length and contact are radius of contact deforming between two elastic bodies on condition of the friction. The calculating formula of pinch force about plate-strip pinch mill was given and the results were analyzed that friction coefficient and radius of pinch rolls are very important for determining pinch force. Moreover, the rule of deforming and stress distribution of different 〓 ratio were gained on condition that the deforming was considered to be non-uniform distribution in the gap. The differential equations were got that calculate the displacements of large deflection of elastic cantilever rectangle plate with fixed end and the formula of the Finite Strip Method was conducted to study the regularity of mid-plane displacements, deformation and stresses for elastic-plastic large deflection bend of cantilever parallelogram plate with fixed or slidable end by integrating Prandtl-Reuss equation.

建立了一套完整的设计参数计算公式和在成型过程中理想带钢或具有月牙弯带钢的工艺参数的调整公式；在考虑摩擦力的条件下，对两弹性体接触变形过程中的接触变形区长度和接触弧半径用位移解法进行了研究，推导了板带递送机的递送力计算公式，从而得知在递送机设计过程中，应选择适当摩擦系数和辊身直径；另外，还从辊缝内带钢实际变形出发，分析了对于不同的〓值，带钢的变形规律及应力分布状况；建立了固定端悬臂矩形板弹性大挠度弯曲变形的控制方程，并且在对Prandtl-Reuss方程的积分处理的基础上，导出了固定端和滑动端悬臂平行四边形薄板的弹塑性大挠度的中面伸展位移、变形和应力的有限条元法公式，编写了Fortran语言计算程序，在各种参数条件下，对螺旋焊管成型过程变形规律进行了全面的分析研究，从而为螺旋焊管的生产和进一步的改进提供了理论依据。

In accord with the characteristics of singular integrals in boundary element method for solving problems of thick plates on two parameter foundation,all formulas for calculating singular integrals are set up by selecting the displacements and stresses which satisfy the governing differential equations in this paper,on the principle of virtual energy.

根据双参数地基上厚板弯曲问题边界单元法中所遇奇异积分的特点，选取满足该问题微分控制方程的位移及内力场，建立了全部奇异积分的计算公式，有效地解决了边界元法在该问题应用中高阶奇异积分的计算问题

And by using the initial conditions as well as the end conditions, the dynamic problem is then transferred to a second kind Volterra integral equation about the function of the axial strain with respect to time which can also be solved successfully by the interpolation method. For piezoelectric and pyroelectric hollow cylinders, by following the solving procedure for elastic hollow cylinder and by using the electric boundary conditions, the dynamic problems are transferred to two Volterra integral equations about two functions of time, one is axial strain and the other is related to electric displacement, which can also be solved efficiently and quickly by employing interpolation method. The elastodynamic solutions of hollow spheres, which are made of elastic, piezoelectric and pyroelectric materials, respectively, for spherically symmetric problems are also obtained.

对于弹性空心圆柱，通过引入一特定函数将非齐次边界条件化为齐次边界条件，然后利用正交展开技术，导出关于时间函数的方程，再结合初始条件和端部边界条件，将原问题转化为关于一个时间函数的第二类Volterra积分方程，运用插值法可给出此积分方程的解；对于压电和热释电空心圆柱，利用求解弹性空心圆柱相似的方法，再结合电学边界条件，原问题转化为关于两个时间函数（轴向应变和与电位移有关的函数）的第二类Volterra积分方程组，同样可用插值法来构造相应的递推公式高效地求解此积分方程组。

This paper analyzes the compound attractor structure of a new three-dimensional autonomous chaotic system.

分析了一种新的三维自治混沌系统吸引子的复合结构。

ON shut rivals out of their transmission systems and shy away from reinvesting their profits in network improvements.

ON将竞争者挡在了其输送体系之后，并不愿将其收益再投资于网络改建工作。