evolute surface

The paper explains three types of evolute of cone curve,and introduces curvature center on top of cone curve and drawing way with compasses and ruler of curvature circle.

给出了三类圆锥曲线的渐屈线方程 ,介绍了圆锥曲线顶点处的曲率中心和曲率圆的规尺作图方法。

In the paper,the spherical evolute by the geodesic distance on the unit sphere is defined and some of its properties are investigated.

本文利用单位球上的测地距离定义了球面渐屈线,并研究了球面渐屈线的一些性质,同时按照Bruce J。