第一次导数

In Part I, the biharmonic equation are chosen, and the boundary peanlty finite method using piecewise cubic Hermite elements is used to seek their approximate solutions, in particular satisfying the derivative and periodical boundary conditions.

在第一部份里，选择使用片断三次 Hermite元素的边界惩型有限元素法来求解满足边界导数条件和边界周期条件的重调和方程式的近似解。

Because of the condition of 〓 for two neighbour parametricspline surfaces is too strong,here,instead of it,some simple and practicableconditions of 〓 resulted from the general theorem obtained by Prof.LiuDing Yuan in Chapter 1 were proved,and three 〓 triangular splinesurfaces schemes wre presented:one is piecewise cubic spline surface patcheshaving local 〓 and whole 〓 continuity based on the refined HCTtriangulation,another is the same degree spline surface patches but based onthe refined Powell-Sabin triangulation,the third is piecewise quartic splinesurface patches having local 〓 and whole 〓 continuity based on therefined P-S triangulation.

由于对参数曲面，一阶导数连续的要求较强，我们采用第一章从刘鼎元定理导出的简单实用的几何连续条件，讨论了基于HCT加细三角剖分和P-S加细三角剖分上的两种局部达一阶导数连续而整体有一阶几何连续的分片三次样条曲面构造算法，一种局部达二阶导数连续整体有一阶几何连续的分片四次样条曲面构造方法。

First, we take the analysis of phase-plane on the invariant plane for the perturbed and unperturbed systems.

在第一章绪论中，我们简要介绍了近可积系统的相关内容，给出了具五次和导数项的非线性Schrodinger方程的物理背景，数值实验结果，研究状况以及本文所讨论的基本内容。

His prospective father-in-law, however, reneged, perhaps making this not only the first derivative but the first default on a derivative.

他未来的岳父，但食言，也许这不仅使一阶导数，但第一次违约的衍生产品。

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％。