围线积分

So-called contour integral is an integral whose integral route is contour.

所谓周线积分是指积分路径是围线的积分。

When the stress and displacement fields in a specimen are calculated by finite element method, the stress intensity factors K and K of mixed-mode crack can be obtained immediately by a contour integral.

此方法与积分路径的选择无关，用有限元法计算出远离裂纹尖端的位移场和应力场，就可通过计算绕裂端的围线积分，精确地给出混合型裂纹的应力强度因子KⅠ和KⅡ的数值解。

The SEM poles have been calculated theoretically by using the iterative method and contour integral method so far, but the both methods have many defects.

为了从理论上得到散射体的极点，人们提出了许多的数值计算方法，如Newton迭代法，Muller迭代法和围线积分法等，但都存在种种缺陷。

In this paper,the boundary singular kernel method in Reproducing Kernel Paicle Method has been applied to impose the essential boundary conditions in EFGM by revising the MLS shape function.The stress field and the displacement field are analysed by linear elastic theory.The contour integral method is used to calculate the J-integral,then the stress intensity factors of mixed-mode crack is acquired.The correctness and the validity of the method are validated.

本文将再生核质点方法中的边界奇异权方法引入EFGM中，通过对MLS形函数进行修正实现了本质边界条件在节点处的精确施加；运用线弹性断裂理论分析裂纹板的应力应变场，采用围线积分法计算J积分，给出了复合型裂纹板的应力强度因子的无网格伽辽金方法。

And the keytechniques are in the following:(1) The algorithm and program of intensified node arrangement near crack tip andalong crack line (2) The shape function calculation of point near crack based on visibility criteria (3) The contour integral method for calculation of stress intensify factor K_ⅠK_Ⅱ(4) The rock slope appraisal method using circular method, polygonal method orgraph theory method depending on the slope joints combination

程序实现的关键技术和算法如下：(1)沿裂隙结点布置及裂尖结点加密的算法及程序(2)采用可视准则的形函数算计算程序(3)围线积分计算复合型裂纹裂尖强度因子K_Ⅰ、K_Ⅱ的算法及程序(4)圆弧搜索法、折线搜索法和无网格—图论搜索法的算法及程序

By applying contour integral method and high-order displacement functionsof MM,we obtain the accurate stress intensity factors of mixed-mode crack.Then,the open crack propagation of the mixed mode I and II is simulated by means oftheories of linear elastic fracture mechanics.This provides a simple and effectivenumerical way for crack evolvement studying.

接着，文中采用围线积分法和流形方法的高阶位移函数来计算得到比较准确的混合型裂纹尖端的应力强度因子，然后基于线弹性断裂力学的裂纹扩展准则，用流形方法实现了平面I-II混合型张裂纹扩展的数值模拟，为数值方法研究裂纹的演化行为提供了一条简单而有效的途径。

Faraday's law is that when the flux in the conductor loop changes, it produces electromotive force in the conductor loop, and obeys to contour integral law , Maxwell Curl Theory is that when the magnetic intensity of a certain point in ether space changes, there produces electric field at that point in ether space, which is the field mutual production theory of "electric field produces magnetic field and magnetic field produces electric field" in the free space which everybody is familiar with, and it obeys differential law , Lorentz magnetic force is that when metal electrons cut magnetic lines, metal electrons forced by move along the conductor to form inductive current, in fact, it doesn't matter whether coil moves or magnet moves, only if there exists relative motion between magnetic field and conductor, metal electrons must cut magnetic lines, which is,"coil stills while magnet moves to the left" and "magnet stills while coil moves to the right" these two situations are the same, which both belong to metal electrons having cut magnetic lines.

法拉第定律指导体环路里的磁通量发生变化时，在导体环路上产生电动势，而且服从围线积分律；麦克斯韦旋度理论指以太空间某点的磁场强度发生变化时，在以太空间的该点产生电场，即大家熟知的自由空间里"电场生磁场与磁场生电场"之互生场理论，而且服从微分律；洛伦兹磁力指金属电子切割磁力线时，金属电子受力沿着导体漂移而形成感应电流，其实，无论线圈运动或是磁铁运动，只要磁场与导体存在相对运动，则金属电子必然切割磁力线，即，"线圈静止而磁铁向左运动"与"磁铁静止而线圈向右运动"这两种情况是一样的，都属于金属电子切割了磁力线。

First local surrounding-line integral bispectrum feature is extracted from the bispectrum of one dimensional range profile of space target, then BP neural network is used for target identification so that the network weights will not be the local lowest value.

提出了基于局部围线积分双谱的空间目标识别算法，从空间目标距离像的双谱中提取出局部围线积分双谱特征。

Based on this definition, the curvature、regular and integral properties of the general offset curve are discussed. As a result, J.steiners celebrated theorem of the oval is developed.

并在此基础上做相应的讨论，研究其正则性、曲率和积分性质，推广了J.steiner关于卵形线的外等距线所围面积的一个著名定理。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。