平面曲线

Since cross ratio is an invariant of the group of all Mbius transformations,and a Mbius transformation maps a circle into another circle, it is convenient to represent a segment of circular arc with a parametric complex rational function.

利用Mbius变换的保交比性质和保圆性质，给出了一种快速、简便地生成平面上的一段精确圆弧曲线的新方法。

This essay studies the graph characteristics method of parameter curve and its describing mdthed and the evaluation of the plane region area closed by itself.

研究参数方程所示曲线的图象特点及描绘方法、自身封闭所围平面图形的面积的求法，弥补了现行教材的不

Planar discrete clothoid splines and discrete clothoid spline surfaces of Schneider and Kobbelt are just constructed by assuming that the curvature of the curves or surfaces is piecewise linearly distributed.

Schneider和Kobbelt的平面离散布状样条曲线和封闭控制网格上的离散布状样条曲面正是利用曲率逐段或逐片线性分布构造出来的。

The wavelet coefficient energy group of time-frequency surface has distinct difference for different swept extent.

储层的孔隙度和电阻率曲线间微差形态波形的复杂程度隐含着储层含油气性的信息，油层水淹程度不同，其时频平面上小波系数能量团存在着显著差异，随水淹程度加重，其能量团分布由复杂逐渐趋于简单单调。

The methods of development for cones and tangent surface on C-Bézier curve and the complex surfaces are obtained.

首先，构造了C-B？zier曲线上的锥面和切线曲面，分别建立了它们到平面的等距映射，给出了C-B？

Two projective line pencils take shape curve of seeond order,which can help ua to determine all kinds of type of curve of second order what is in two concurrent affine planes.

对二射影对应线束形成二阶曲线的图形分析，可以帮助我们用作图法确定共面的二仿射平面场对应线束形成的二阶曲类

In this paper, instead of corresponding image points which are widely used in the literature, corresponding image conics are used to calibrate a rotating camera.

摘要研究探讨了一种基于平面二次曲线的纯旋转摄像机自标定方法。

The grids can be densified locally where the flow is complicated for the sharp change of water depth.(5) 2-D hydrodynamic equations in the generalized curvilinear coordinates have been derived with the contravariant velocities as main variables. The new equations keep the original styles and physical meanings. Based on the water depth correction method, the 2-D flow numerical model has been established and validated by the measured data.

推导了广义曲线坐标系下以逆变流速张量作为主变量的二维水动力方程，新方程保持原有结构形式及物理含义，采用水位校正法建立了二维水流数学模型，经实测资料验证后的模型，模拟并分析了分流角度、宽深比等因素变化对分汊流平面二维水流结构的影响。

In the direction perpendicular to the rolling plane convex curve was continuous basic cylindrical or conical roller to prevent roller and raceway contact points to the stress concentration.

在垂直于滚动方向的平面内呈连续的微凸曲线的基本圆柱形或圆锥形的滚道，以防止在滚子与滚道接触处产生应力集中。

The lens has a section in a plane normal to a longitudinal axis of the lens, in which a surface of the lens facing the light source has a curved line that expands or is convexly facing toward the light source.

所述透镜在与透镜的纵向方向垂直的平面上具有截面，在该截面中，透镜的面向线光源的表面具有朝向光源扩张的曲线。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了