曲面

The quadrature formula about surface integral on any quadrilateral element is deduced by means of isoparametric transformation and bilinear interpolation.

通过对三维有界区域的边界曲面作四边形网格剖分，用有限元方法处理高斯公式中的曲面积分，由等参变换及双线性插值导出任意四边形单元上曲面积分的数值求积公式。

Chapter 7 discusses a orientational classification principle of curve and surface. With this principle, we have accomplished the frame automate generation and a boolean operation between surfaces.

第七章描述了一个曲线、曲面的有向性分类原则，在ZD_ADM曲面造型系统中，运用此有向性分类原则，实现了二维轮廓线的自动生成和曲面间的布尔运算。

The method submits a practical solution to the data exchange problem between the two kinds of different topological surfaces. The author gives the details of surface regularization, boundary extraction and skeleton curve construction in this chapter.

本章对三角曲面裁剪重构的方法、实现及应用进行了系统研究，并对其中的若干关键问题，例如三角曲面的整体规范化、原始曲面边界提取及母面骨架线构造等，进行了深入探讨。

For the quartic blending surface , we study the part of which meets and forms a connected closed surface together with .

对于四次拼接曲面，我们感兴趣的是其联结三个管道曲面并且可与形成连通的封闭混合曲面的部分，我们称之为拼接曲面的"有效部分"。

On the basis of analysis and comparison of their strengths and weaknesses, each method can find its applied occasion. With energy method, we can conveniently control the precision of the objective surface and add boundary constraints for preserving the models global geometric continuity, but this method is very time-consuming.

其中基于能量原理的光顺方法能够方便地控制目标曲面的精度和边界条件，从而能够实现曲面模型的全局连续性，但是能量法的运算速度还有待提高；刚度调整法实现简单，但是生成的曲面的可编辑性较差；小波分解方法计算速度很快，能够有效地实现数据压缩，但是其逼近误差和边界条件却难于控制。

E. , G〓 continuous splice between surfaces and local convex estimation of surface.

本文还总结、分析了基于车身工程图建立曲面模型的基本方法，研究了建模中的两个关键问题，即曲面G〓连续性拼接和曲面局部凸性的判断。

In this paper,from the global viewpoint we first define the nonlinear control system on a two dimensional surface in the three dimensional Euclidean space, give the represwentation of the state equation under a loca coordinate sysgtem of the surface, and study the connectin between the equilibrium state of the nonlinear system and the egodesics on the surface.

我们首先从整体化的观点定义了一种建立在三维欧氏空间的二维曲面上的非线性控制系统，并给出了在曲面的局部坐标系下非线性系统状态方程的表达式，研究了非线性系统的平衡态与曲面的测地线之间的关系。

The four varistors form the Wheatstone full bridge. Two lateral sides of cantilever and overload protection structure are fabricated using DRIE technology. A novel overload protection curvature is designed to be similar to the cantilever bending shape which is bearing the greatest acceleration. This design increases the overload protection and improves the vibration damping of accelerometer to the critical damping.

悬臂梁两侧面和过载保护曲面采用DRIE技术加工，过载保护曲面设计成近似于冲击加速度传感器承受最大加速度时悬臂梁弯曲曲面的形状，一方面提高了悬臂梁过载保护能力，另一方面可以调节加速度传感器的工作阻尼至临界阻尼，有效提高了加速度传感器的工作频率带宽。

The minimal surface have been extensively employed in many areas such as architecture, material science, aviation, ship manufacture, biology and crystallogeny and so on. In this paper we have some element works on minimal surface from the point view of CAGD It is well-known that there does not exist any other quadratic minimal surface except for the plane.

以肥皂膜问题为物理背景的极小曲面问题或者Plateau问题—寻找以给定空间曲线为边界的面积极小的曲面，从18世纪提出到现在一直是微分几何和偏微分方程理论的重要课题，微分几何领域已经有了极其丰富的极小曲面理论。

At and , we can get a univariate cubic equation in and its three roots . By the dependence of the roots and the coefficients of the equation, we can choose corresponding space points ( such that the distance is the shortest from to the point with parameters and . Thereby we can get all the data of discrete points on the cubic curve of blending surface at . Again we denote the maximum value and minimum value of planar parameter with which meets by and respectively.

利用根与系数的连续相依性，可以选相应的空间点使其距离的圆截线上对应值的点最近的两个根，从而得到处拼接曲面的截线的离散点的数据并确定出与相截的平面参数的最大最小值类似地由处拼接曲面截线的离散数据得到处的离散数据，这样可以依次计算出拼接曲面上对应所有参数点的离散点的坐标。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。