曲线坐标系

On depending on author's perception of teaching 《analytical geometry》,raising a warning about the phenomenon of student's neglect of the use of vector in exercise,this essay elucidate the preponderance of vector in solving problems about space.

在中学，解析几何课程主要研究平面上一些点、线的几何位置和几何性质，所涉及的点、直线、曲线均共面，它们都落在坐标系所在的平面内。

For this purposewe need to develop some new methods and new techniques.For example we studythe properties of the"centroid curve"and the"auxiliary curve",and identify twoplanes in which these two curves are defined respectively;we also use the relationshipbetween the"centroid curve"and its"dual curve".

为此需要发展一些新技巧和新方法，例如研究由Abel积分之比定义的"质心曲线"和"辅助曲线"的几何性质，并把这两条在不同平面上定义的曲线放在同一个坐标系中考虑，或把"质心曲线"与其"对偶曲线"联系起来考虑。

The offset direction is defined by the local coordinate system, which is formed of the tangent vector and the normal vector of every point on the curve.

本文利用曲线上各点的切向量和法向量所形成的局部坐标系来确定等距方向，从而给出一种广义偏距曲线的新定义。

In view of the inclining error in installing to the work-piece in lapping, an analytic method for profile error is presented, new and old rectangular coordinates are established, and error model of work-piece between its actual and ideal curve is deduced through coordinate transform.

针对研磨中工件的安装倾斜误差，提出了导致工件面形误差的分析方法，建立新、原坐标系，应用坐标变换，推导出工件曲线上各点相对理想曲线对应点的误差模型。

According to road designing data of mileage,coordinate,azimuth angle of tangent or straight line,curve radius,the length of spiral line from main point of curve or straight line starting point,we can calculate the coordinates of center line points and boundary line point s in any form of road under the same coordinate system.

根据线路设计资料提供的曲线主点里程、坐标、切线方位角、曲线半径、缓和曲线长度的已知数据，计算出任意线形的中桩、边桩在线路统一坐标系中的坐标，利用全站仪极坐标放样程序，以线路附近的控制点或加密点为测站，准确、快速放样各点。

For example, we study the properties of the"centroid curve" and the"auxiliary curve", and identify two planes in which these two curves are defined respectively; we also use the idea of homotopy method to prove a fact that the orbit of a differential system has no triple contact point with the line we considered. Another key technique, which we use several times, is deformation argument.

例如研究由Abel积分之比定义的"质心曲线"和"辅助曲线"的几何性质，并把这两条在不同平面上定义的曲线放在同一坐标系中考虑；利用拓扑中同伦的思想来证明微分系统的轨线不可能与某条直线三重相切；利用几何方法与分析计算相结合证明了某一曲线是正则的；以及连续变动参数的技巧。

Engineers can compare calculation results with the tunnel design curve in order to obtain deviation values of horizontal position, vertical position and angles of the shield machine, and can adopt these results to control tunneling operations of the shield machine.

隧道设计曲线是在城市三维坐标系中设计的，要得到盾构机掘进过程中的误差，就必须通过测量计算得到盾构机在绝对坐标系中的坐标位置和方位角。

For the regular curves, we find two Killing fields for the purpose of integrating the structural equations of the p-elastic curves and express the p-elastica by quadratures in a system of cylind...

对于正则曲线的情形，我们发现了两个用于求解p-弹性曲线的结构方程的Killing向量场并用积分将p-弹性曲线在一个柱面坐标系中表示出来，而对仿射星形曲线的情形，我们用积分方法解出了欧拉-拉格朗日方程，利用Killing向量场及线性李代数s1(2，R)、s1(3，R)和s1(4，R)的分类将高阶结构方程降为一阶线性方程，因此我们用积分完全解出了中心仿射p-弹性曲线。

For the regular curves, we find two Killing fields for the purpose of integrating the structural equations of the p-elastic curves and express the p-elastica by quadratures in a system of cy...

对于正则曲线的情形，我们发现了两个用于求解p-弹性曲线的结构方程的Killing向量场并用积分将p-弹性曲线在一个柱面坐标系中表示出来，而对仿射星形曲线的情形，我们用积分方法解出了欧拉-拉格朗日方程，利用Killing向量场及线性李代数s1(2，R)、s1(3，R)和s1(4，R)的分类将高阶结构方程降为一阶线性方程，因此我们用积分完全解出了中心仿射p-弹性曲线。

For the regular curves, we find two Killing fields for the purpose of integrating the structural equations of the p-elastic curves and express the p-elastica by quadratures in a syste...

对于正则曲线的情形，我们发现了两个用于求解p-弹性曲线的结构方程的Killing向量场并用积分将p-弹性曲线在一个柱面坐标系中表示出来，而对仿射星形曲线的情形，我们用积分方法解出了欧拉-拉格朗日方程，利用Killing向量场及线性李代数s1(2，R)、s1(3，R)和s1(4，R)的分类将高阶结构方程降为一阶线性方程，因此我们用积分完全解出了中心仿射p-弹性曲线。

Lugalbanda was a god and shepherd king of Uruk where he was worshipped for over a thousand years.

Lugalbanda 是神和被崇拜了一千年多 Uruk古埃及喜克索王朝国王。

I am coming just now,' and went on perfuming himself with Hunut, then he came and sat.

我来只是现在，'歼灭战perfuming自己与胡努特，那麼，他来到和SAT 。