积分元

The boundary element simulation method for the interaction of oblique linear waves with long prismatic floating ocean structures with arbitrary cross section is investigated by using the second kind modified Bessel function. The singular integral method in a constant or linear element and the open boundary treatment are proposed.

采用第二类变形Bessel函数对斜向线性入射波与任意截面形状的长棱柱型浮式海洋结构物的相互作用问题进行了边界元法模拟，给出了常数元和线性元的奇异积分处理方法以及开边界的处理方式。

By using thenatural boundary element method which is set up by professor Feng Kang,the Neu-mann boundary problem of the harmonic equation on the half-upper plane is reducedto the Hadamard type singular integral equation,the integral region of which is un-bound,and then we turn it into corresponding bilinear form.

通过由冯康教授开创的自然边界元方法，将上半平面调和方程的Neumann边值问题归化为Hadamard型强奇异自然边界积分方程，并且此积分方程是无界域上的强奇异自然边界积分方程，然后将它转化为相应的变分形式。

VIP POINTS:1 RMB = 1 points, the corresponding integral can be related to the gift exchange.

VIP积分：1元人民币=1积分，相应的积分可以换取相关的礼品。

This article use the improved integral inequalities with the deviate variable and some skills of inequalities as well as related knowledge about second-order differential equation,to obtain the following results: the classification of limit point case or limit circle case and boundedness for second order differential or difference equation with deviative variable,discussed the classification for certain n-order differential equations,Criteria for the classification of second order differential equation with deviative variable.

本文利用推广的具有偏差变元的积分不等式，结合不等式的一些技巧以及常微分方程的相关知识对一类二阶具有偏差变元的微分方程及一类二阶差分方程极限圆型的分类问题作了相关的研究工作，并且讨论了一类n阶具有偏差变元的常微分方程解的平方可积性与有界性和一类二阶非线性具有偏差变元的微分方程解的有界性。

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。

Different kinds of integrations have to be evaluated in boundary element methods. The nearly singular integral is the most difficult one of them. A self-adaptive Gauss integral method is proposed to divide the element into finer meshes under the specified conditions.

边界元法通常需要采用数值方法解决单元内的各种积分问题，而准奇异积分是各种积分中数值处理最为困难的部分。

The integration by second substitution is an important method of calculating indefinite integral,it has a certain application,it usually applies to calculate some integrals of irrational function.

第二换元积分法是求函数不定积分的一种重要方法，具有一定的适用范围，对某些无理函数的积分的求解通常使用该方法。

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

In the past, there exists difficulty for calculating nearly singular integrals arising from boundary element analysis of the problems of thin body. However, by now, the difficulty of nearly singular integrals has been resolved by analytical integral algorithm, which has been put into uses in analyzing the conventional structures and thin body structures in the potential problems.

过去边界元法求解薄体结构存在着几乎奇异积分的困难，目前几乎奇异积分问题已得到成功解决，解析积分算法也已成功应用于分析二维位势问题常规结构和薄体结构。

We can lead out the equivalent border integral equation by Green the second equation,dividing the inner border in the liquid into a series strip of awls shell or cylindrical shell ,and solve border integral equation along different segment of border, then lead out border integral equation.

由Green第二恒等式导出等价的边界积分方程，将液体内边界分成一系列锥壳或柱壳状条，对边界积分方程进行分段积分，导出边界元格式方程。

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。