variational integral

A relation between boundary integral equations and variational principles is discovered for the first time. And a one-to-one correspondence between boundary integral equations with direct and indirect unknown quantities is indicated.

文中首次阐明了边界积分方程与变分原理的内在的联系，还指出了间接变量与直接变量两类边界积分方程之间存在着一一对应的关系。

A boundary integral equation and variational formulation for the solution to a class of periodical parabolic equations is presented, which is a heat conduction equation. The error estimates of the approximate solutions are given.

得到了周期性热传导抛物型方程的边界积分方程和边界变分方程，给出了近似解误差估计。

The function?? is called a trial variation function and the integral in ( 8. 1) is called the variational integral.

函数？斫凶龀⑹员浞趾0数，（8.1）式中的积分叫做变分积分。

In order to alter the integral length automatically, the paper uses a method of variational integral length to trace vector field depending on the emanative degree of vector field.

作者根据矢量场的变化程度，动态地修改积分步长，采用一种变步长的积分方法对矢量场进行流线跟踪。

The author gives the canonical equation of generalized classical mechanics, and then studies its nonsimultaneous variational equations and their solutions, and proves that integral invariant of the system can be constructed by using the first integral.

给出了广义经典力学的正则方程，研究了其非等时变分方程，讨论了它们的解，并证明可由第一积分构造相应的积分不变量。