切线平面

Firstly, the curvature continuity conditions between two adjacent rational quadratic curve segments are derived. Secondly, an optimal algorithm is presented for solving out the tangent lines at every points of a closed point set in a plane.

首先导出了两相邻二次曲线段间曲率连续的拼接条件，然后提出了求解平面上一个闭的点列中每一点处的切线的最优算法。

Results and Conclusion\ This paper gives the concept of bilaternal angle density and coangle density of fractal sets, gives definition of tangent and tangent plane of fractal sets, and discusses its existing conditions.

结果与结论给出分形集的双侧角密度与余角密度的概念，通过它给出了分形集的切线与切平面定义，并讨论了它存在的条

By means of the fractions of the equation of the non一ideal constrained motion of the particle along the plane curve on the tangential direction and normal direction,the motion speed expression of the particle under this condition is derived,the constrained counter force is further gained,thus some non一ideal constraint problems are solved from the given angle.

通过质点沿平面曲线的非理想约束运动方程在切线和法线方向上的分式，导出质点这一条件下的运动速度表示式，并进一步求出其约束反力，从一定角度解决一些非理想约束问

Theory; the spatial meshing theory includes comparative motion, comparative differential and conjugative curved surface; and the application of meshing theory includes gear drive and worm drive. The spatial meshing theory is the main part of the course.

课程的重点讲解内容有曲线的参数方程、切线、法面、弧长、曲率、空间曲线的基本公式、挠率及平面曲线的基本公式等；曲面第一和第二基本公式，法曲率、主方向和主曲率、欧拉公式、短程挠率、欧拉公式和贝特朗公式推广、相对法曲率和相对短程挠率等；刚体的绝对和相对运动速度、相对微分和绝对微分、相对速度和相对微分、轨迹曲面的法曲率和短程挠率等；空间共轭曲面的啮合条件、诱导法曲率、两类界限点、等距共轭曲面、空间啮合的二次接触原理等；蜗杆传动的数学模型建立及啮合特性分析方法等。

The position of said examine bed on scanning plane and its sag from its nominal position can be found out according to the tangent channel of X ray along the outside near bed back and the geometric structure of X-ray emitting and detecting unit.

在通过X射线照射和探测装置扫描安置在检查床上的受检者的X射线CT设备中，根据沿切线方向向检查床背侧附近外侧前进的X射线被探测的通道位置和X射线照射和探测装置的几何结构，找到检查床在扫描平面中的位置。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。