积分分布函数

A method for the generation of Weierstrass fractal surface is presented,based on Helmholtz equation,with the Kirchhoff approximation,the calculus formula of light scattered field on the 1-D Weierstrass fractal suface is deduced.

采用Weierstrass分形函数模拟实际粗糙表面，从简谐光波满足的亥姆荷兹方程出发，利用基尔霍夫近似推导出一维Weierstrass分形粗糙表面的光散射场的积分公式，考虑遮蔽效应后数值计算并分析了表面散射光强的角分布特性。

The edge internal branch crack of half-plane can be considered as a superposition of many single cracks, thus a set of Cauchy singular integral equations can be formulated, where the distributing dislocation density serves as the unknown function.

将半平面边缘内分又裂纹问题看作是许多单裂纹问题的叠加，建立了以分布位错密度为未知函数的Cauchy型奇异积分方程组。

In the numerical calculations,the unknown density of dislocation is approximated with the product of fundamental function and Chebyshev polynomials.The calculations show the present method yields rapidly converging and high accurate numerical results.

在数值求解这组奇异积分方程中未知位错分布密度近似为基本密度函数与Chebyshev多项式之积，计算表明，本文方法的数值结果不但收效快而且精度高。

The paper includes:The author calculate the structures inner force and displacement of the free end , analyze the influence of the height and the value of pretress of cable by making use of ANSYS 9.0 soft, pose the concept of critical prestress,conclude the function relation between displacement of the free end, initial strain and the height of cable ,analyze the dynamic properity and point out that Newmark-β method should be adopted when we analyze the dynamic properity of the cable-stayed spatial structure with direct integral test to guarantee the contribution of high mode,finally conclude the functional relation among coefficient of earthquake inner force, initial strain and the height of cable, wish to get some helpful conclusion applied to cable-stayed spatial truss design.

本文系统介绍了斜拉空间桁架竖向地震反应的分析理论与方法、详细分析了斜拉空间桁架结构在静力和竖向地震作用下的受力性能，主要内容包括：利用通用有限元软件ANSYS9.0计算了斜拉空间桁架在静力和竖向地震作用下内力及自由端位移分布规律并得出地震内力系数与节间位置、预应力以及斜拉索高度之间的函数关系；详细分析了斜拉索中施加的预应力以及斜拉索高度的变化对于该种结构内力及自由端位移的影响并提出了斜拉空间桁架的临界预应变概念，进而得到了自由端位移与初始预应变以及斜拉索高度的函数关系，即：△=-(40h+2180)ε+9.8；分析了该种结构的动力性能，并指出：在时域内采用直接积分法计算该种结构的动力响应时，应该考虑采用不引起振幅率减小的Newmark-β法，以保证高阶模态响应的贡献仍然保留在响应中而不致于被忽略。

The conduct of the content of definite integral application by usual mathematics analysis teaching materials is not strict enough in theory.

定积分是计算闭区间上非均匀分布量的一个重要方法，而在用定积分计算某量时，被积函数往往不是现成的，需要我们先"找"出来。

The results show that the key of this algorithm is the solution of the integral operational matrix of orthogonal function.

研究结果表明：基于正交函数逼近法的分布参数系统参数辨识算法的关键在于正交函数正、反向积分运算矩阵的求解。

When computing the diagonal elements of the Galerkin matrix, one will encounter the integral of Hankel function, the Green's function of 2-dimensional Helmholtz equation and the cosine weighting function, whose integrand is singular in the integration range. A new approach is proposed to deal with this kind of singular integrals, which is pivotal but have not been reported so far.

首先建立了透镜边缘上任一点的电场满足的边界积分方程，然后选择适当的正交模式函数展开端口上的电场分布，采用边界元法的思路及Galerkin法将该积分方程离散化为—矩阵方程求解即可得到透镜的多模式散射参数。

Based upon the general equations of a trans-versely isotropic foundation, the stress functions and the theory of Fourier transforms , the basie displacement so-lutions for a transversely isotropic body under horizontal concentrated loads are obtained.

根据横观各向同性体的基本方程，运用应力函数、傅氏变换和傅氏逆变换理论，得出了横观各向同性地基在水平集中荷载作用下的基本位移解，然后利用积分的方法分别得出了横观各向同性地基在条形面积上水平均布荷载、水平三角形分布荷载及水平梯形分布荷载的位移计算公式，并利用实测的一组弹性参数，将横观各向同性地基中的相对位移与现有的计算理论给出的各向同性地基中的相对位移通过图形作了分析比较，得出了一些有益的结论，以供岩土工程设计人员参考。

The gamma function calculation of Pearson type III distribution is investigated,a new approximation method by using cone curve is put forward,and neither numerical integral nor series expansion may be used.

对皮尔逊Ⅲ型分布公式中伽玛函数的计算问题进行了研究，提出了一种新的数值逼近方法，在一定范围内对伽玛函数用圆锥曲线表示，利用递推公式扩大参数范围，免去了数值积分和用级数展开计算的麻烦。

The method is to add a term into the original singular kernel while it subtracts its analytical solution from the original equation. Since the singularity of Green's function can be eliminated by such a mathematical technique, shape function does not need to be supposed while solving the unknown. The calculation can be directly applied to the real shape of the object by taking the integral points distributed on the object as nodes that satisfy boundary conditions.

由於格林函数的奇异性经过数学上的技巧加以消除，因此当求解未知数时已经不需要再假设形状函数，即可直接使用物体真实的外型来做计算，也就是直接将物体上分布的积分点视为满足边界条件的节点。

No clear conclusions can be made about the predictie alidity of specific measures, they found, except for criteria for the underuse of drugs for cardioascular disease.

除了心血管病不合理用药标准外，对于特定评价方法的预测效度没有明确的结论。

The third and last is that almost all of them, being infinite in number, have been impostures, and by idle and crafty brains merely contrived and feigned after the event past.

第三、即最后一点是：几乎所有这些不胜枚举的预言都是欺人之谈，都是在事件过后由无聊而狡猾的脑筋推测与凭空捏造的。