查询词典 iterated integral

Double integral the definite integral of thinking to a three-dimensional space, have been more practical application, but it can be said of their way of thinking and the definite integral of exactly the same.

二重积分把定积分的思维推向了三维立体空间，得到了更多的实际运用的地方，但其思考方法可以说和定积分的完全一致。

In calculation of definite integral,beginners tend to use three methods of calculation:(1)Leibniz formula,(2)integration by substitution of definite integral,(3)integration by parts of definite integral.

在定积分计算中初学者常用的计算方法有三种：(1)利用牛顿-莱布尼兹公式，(2)定积分的换元积分法，(3)定积分的分部积分法。

The definite integral property in symmetry interval is extended to definite integral on non-symmetry interval and multiple integral.

在定积分和重积分中对对称区间上奇偶函数的定积分性质进行了推广。

Integration : definite integral, double integral, applications of the integral.

本科目介绍数学里最常应用於商业、经济上的几个概念和方法。

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 traditional virtual boundary integral expression is based on the extension of single layer potential, for the integral formulas related to single layer potential for parabolic problem, the numerical computation of the exponential integral function is unavoidable.

通常的虚边界积分公式是利用单层位势的延拓来建立虚边界元积分方程，但对带时间变量的单层位势，要涉及到指数积分函数的计算。

As a foundation, the definition of elementary integral transformation and the method to factorize an integral matrix with elementary integral transformation is proposed firstly. After that, the problem how to find identification vectors in Modular-S-invariants is solved.

文中首先给出初等整数变换的概念，之后借助初等整数变换对整数矩阵进行分解，并在此基础上给出从加模S-不变量中求取不可达见证向量的方法。

Then, the differential equations are solved by the Fourier expanding and Hankel integral transform method. Integral solutions of soil skeleton displacements and pore pressure as well as the total stresses for poroelastic media are obtained. Furthermore, a systematic study on Lamb's problems in transversely isotropic saturated half-space is performed. Integral solutions for surface radial, vertical and tangentical displacements are obtained both in the case of drained surface and in the case of undrained surface excited by vertical and tangentical harmonic resources respectively. Numerical results show the obvious difference between the model of isotropic saturated poroelastic media and that of transversely isotropic saturated poroelastic media.

其次，基于Biot波动理论，在圆柱坐标系下求解了横观各向同性饱和土的Biot波动方程：通过引入位移函数，在圆柱坐标系下将横观各向同性饱和土的Biot波动方程转化为两个解耦的6阶和2阶控制方程，然后根据方位角的Fourier展开和径向Hankel变换，求解波动方程，得到以土骨架位移和孔隙水压力为基本未知量的积分形式一般解，并用一般解给出了饱和土总应力分量的表达式；再以基本解为基础，系统地研究了横观各向同性饱和半空间体的Lamb问题，考虑表面排水或不排水两种情况后，首次得到横观各向同性饱和半空间体在表面竖向和水平谐振力作用的下径向、竖向和周向位移的解析解。

By integral transformation of basic equations, the stress and displacement expressions with unknown coefficients of elastic and viscoelastic materials were obtained in Laplace domain respectively, and introducing dislocation density functions, the singular integral equations were got according to the boundary conditions and interface connection conditions, further adopting Gauss integration and Gauss-Jacobi integration formula, the problem was reduced to algebraic equations, then it can be solved with the method of collocation dots in Laplace domain. Finally, the time response of dynamic stress intensity factor was calculated with the inverse Laplace integral transformation.

采用积分变换方法，得到Laplace域内弹性和粘弹性材料的应力和位移的含未知系数的表达式；引入位错密度函数，并通过边界条件和界面连接条件，导出反映裂纹尖端奇异性的奇异积分方程组，采用Gauss积分，并运用Gauss-Jacobi求积公式化奇异积分方程组为代数方程组，利用配点法进行求解；最后经过Laplace逆变换，求得动态应力强度因子的时间响应。

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。

Nowadays, most of research are to build a transmutative Petri Nets through adding controlling place sets, controlling arc sets and controlling policy to the basic Petri Nets, while the Controlled Petri Nets could be used to argue many controlling theory problems conveniently and to induce many logically and physically supervisory and solve the Event Feedback Controlling Problems and State Feedback Controlling Problem in DEDS supervisory theory.

目前大多数的研究表现为在变形后的受控Petri网基础上，利用各种方法求得各种逻辑型、结构型控制器，解决DEDS监控理论中的事件反馈控制问题与状态反馈控制问题。

On one hand, there are discussions with the works council and union about extension of short time working up to the end of September.

一方面，有讨论，工程理事会和联盟关于延长工作时间短至9月底。