查询词典 fundamental form

A systematic study on computing the integral curvature line on NURBS surface is presented. Discrete normal is used to simplify calculation of the second fundamental form of the surface, resulting in accelerating the Euler iteration process in solving the differential equation of curvature line. Discrete points on the curvature line are then obtained and approximated by an explicitly presented B-spline curve on the NURBS surface using singular mixed interpolation and capable of controlling the error within a given tolerance.

对NURBS曲面的曲率线的积分进行了系统的公式推导，并利用NURBS曲面的离散法向量有效地简化了曲面第二基本量的计算，加速了Euler法迭代求解曲率线微分方程的过程；在求得曲率线上的离散点集以后，应用奇异混合插值技术，在可控精度内把曲率线用显式直接表示为位于NURBS曲面上的B样条曲线。

In this paper, by computing the Laplace of the square of the length of the second fundamental form and introducing a self-adjoint operator and using Stokes Theorem and Hopf Theorem, we obtained some pinching theorems and rigidity theorems for hypersurfaces and submanifolds in hyperbolic space.

本论文通过计算双曲空间中子流形的第二基本形式模长平方的拉普拉斯和引进一个新的自共轭二阶算子，利用Stokes定理和Hopf定理得到了子流形的一些拼挤定理和刚性定理。

In this paper, we mainly study the gap of the second fundamental form of hypersurface with constant mean curvature in the unit sphere.

本文主要研究了单位球面内常平均曲率超曲面的第二基本形式模长平方的间隙性。

B| denotes the norm of the second fundamental form on M.

4那么 (5)这里a_m=，表示M的第二基本形式的模。

The space-like hypersurfaces with constant scalar curvature in a de Sitter space were studied and a pinching theorem on the square of the norm of the second fundamental form was obtained.

研究de Sitter空间中具有常数量曲率的类空超曲面，将Cheng-Yau的自共轨运算元口作用在对称张量T上，得到了这类超曲面关於第二基本形式模长平方的一个拼挤定理，加强了已有的相应结果。

The resarch studies the space-like hypersurfaces with constant square of length of second fundamental form in locally symmetric Lorentz spaces, Some sufficient conditions for the hypersurfaces to be totally umbilical are obtained.

研究局部对称Lorentz空间中第二基本形式模长平方是常数的类空超曲面，获得了这类超曲面是全脐的若干充分条件。

Let x be an immersion of a compact Willmore surface M into the n-dimensional unit sphere Sn. In this thesis we first consider the Willmore surfaces in the unit 3-sphere, and establish an integral inequality for the square of the length of the trace free part of the second fundamental form and the mean curvature.

令x是一个从紧致威尔摩曲面M到n 维单位球面Sn的浸入，在本论文中我们首先考虑3维单位球面中的威尔摩曲面并建立一个包含第二基本型式迹为零部份的张量长度平方与平均曲率之积分不等式。

For compact hypersurfaces and highcodimension compact submanifolds initial data respectively, we prove that the flow hasa smooth solution for all time under almost optimal conditions. Those conditions arethat the second fundamental form on the initial submanifolds is not too large, the exter-nal force field, with its any order derivatives, is bounded, and the field is convex with itseigenvalues satisfying a pinch inequality.

我们分别对紧超曲面初值和高余维紧子流形初值证明了当初始曲率比较小，并且外力场除了要各阶导数一致有界外，还要满足凸性条件以及特征值的一个pinch条件时，这种热流的光滑解长时间存在。

Life is the ground for the existence of morality, as well as the fundamental form of the existence of morality. Entirety, practicality and generativeness are the major characteristics of the morality for the world of life.

生活是道德存在的根据，也是道德存在的基本形态，整体性、实践性、生成性是生活世界道德的主要特征。

Seam binding is the most fundamental form seam binding but the need to neaten the raw edges of the binding makes its use more difficult.

止口条是这道工序最基本的形式。斜滚边是滚边发展而来的，但需要修剪滚边的毛边，这使得它做起来比较难。

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％。