曲面

Boolean sum projection, P〓P〓, interpolates to a primitive function f along lines; it is a transfinite interpolant.

布尔和曲面投影算子，即Pu〓Pw，沿着曲面片的边界曲线插值被逼函数f，因而这是一种超限插值。

In particular, rotation hypersurfaces of finite type are studied and classified. The existence of rotation hypersurfaces with prescribed principal curvature functions in pseudo-Riemannian space forms is proved.

对有限型旋转超曲面进行了研究，得到分类结果；证明了给定主曲率函数的旋转超曲面的存在性。

Then, based on the mean curvature, Gaussian curvature and the function of principal curvature, the minimal loci of the principal normal surfaces of curves, the curves with constant Gaussian curvature and the two curves of which the ratio of their functions is constant can all be obtained, as well as the properties of geodesic curve and lumbar curve.

再根据平均曲率、高斯曲率及主曲率函数，能得到曲线的主法线曲面的极小轨迹、常高斯曲率曲线及两个主曲率函数之比为常数的曲线。还给出曲面上测地线和腰曲线的性质。

Besides, three new properties of the pencil formed by two quadrics have also been put forward in 3D real projective space in this thesis.

除此之外，本文还给出了两二次曲面形成的二次曲面束在实射影空间的两个新的性质。

Properties to confine types of the quadrics in a quadric pencil in real projective space are summarized and briefly proved in this thesis.

本文对二次曲面束在实射影空间包含的成员的讨论总结了关于二次曲面束的成员组成的一些结论，并给出了非常简洁的证明。

To solve the problems in adjusting and controlling shapes of developable surfaces, following the important idea of duality between points and planes in 3D projective space, two direct explicit and efficient methods of computer aided design for developable surfaces are proposed.

为了解决工程中可展曲面位置与形状难以调整和控制的问题，基于3D射影空间中点和平面间的对偶性这一重要思想，提出了2种直接、简单有效的可展曲面设计新方法。

The segmentation results are proper for quadric surface identification and NURBS approximating in reverse engineering.

该算法在大量的噪声网格模型上获得了较好的分割结果，适用于逆向工程中的二次曲面识别和NURBS曲面逼近。

We call this surface the stress quadric.

我们称这个曲面为应力二次曲面。

An algorithm of feature surface recognition based on quadric surface fitting and geometry property was presented.

提出了基于二次曲面拟合误差分析和几何属性分析的特征曲面识别算法。

It is proved that two images of the quadric surface is not enough to reconstruct the quadric surface.

我们证明了两幅视图轮廓包含的信息不足以重构二次曲面，三幅视图对于恢复二次曲面三维表面是充分而巨必要的。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。