曲率线

A planar geometric spline, biarc spline, is generalized to a 3D geometric spline whose curvature and torsion are all constant.

给出基于非线性规划解的双圆柱螺线样条局部构造法，把平面几何样条——双圆弧样条推广到常曲率和常挠率的空间几何样条。

The ocular accommodation has a great influence on refractive components. It is not only the process by which the refractive power of the lens is increased. But the lens itself moved forward relatively. The accumulation effects of accommodation induced by near-work is the main cause of myopia developed in children. The asymmetry of corneal surface was not only related to keratometer K1 and K2 , even the curvature within the same horizontal or vertical meridian was asymmetry.

调节本身不仅是传统意义上的睫状肌收缩和晶状体变凸，同时还伴有晶状体的相对前移；调节对眼的几乎所有屈光构成因素有着显著的影响，视近活动的累积效应是儿童近视眼发生的主要原因；角膜的非球面性不但表现为两个相互垂直子午线的曲率不等，即便是在同一垂直或水平径线上的屈光分布也是非对称的。

After that the contour is produced by curve fitting and the curvature of every point of the contour is calculated.

然后，用曲线拟合轮廓线，并计算曲线上各点的曲率。

Scan line is used to detect the boundary of the horizontal rim, least square estimation is applied to compute its orientation, and elastic thread techniques is proposed to approach the curve with very low curvature.

提出了扫描线测量横向边框外沿并利用最小二乘法计算其走向的方法以及用来拟合曲率极小曲线的弹性线技术。

A method of determining the radius of curvative of a planar cam profile by Sterling Differentiation is proposed, and then an example is given to demonstrate it.

本文详细介绍了如何用斯梯林插值公式求解凸轮廓线为等间隔离散点的平面凸轮曲率半径方法，并给出了一个例子加以验证。

By means of using a disc cutter with a concave end instead of traditional ball-ended or flat-ended ones,and adjusting the cutter axis to move relatively to the component being machined according to some special rules,the envelop formed by the trace of the tool-nose in each pass and the required surface have the same derivatives up to the second order in the plane normal to the feeding direction.

采用二阶密切曲率法，即采用中凹的盘形铣刀取代传统的球头或鼓形铣刀，在每一行程中让刀具轴线相对于工件按特定的规律摆动，使得在垂直于进给方向的法截面中，由刀尖轨迹形成的包络面与理论曲面的法截线具有相同的1阶？

The torsion of the intersection curve of two surfaces in R3 can be expressed by geodesic torsions,normal curvatures and the angle between surfaces.

即两曲面交线的挠率可以用两曲面的测地挠率、法曲率及两曲面的夹角表示。

Included are the measurements of the tooth profile deviation of a shaving cutter based on the generalized polar coordinate method, and of the helix deviation of the shaving cutter using curvature method to automatically identify the boundary points; the measurements of the tooth profile of a modified hobbing cutter, and of deviation of contact line of the hobbing cutter by means of the generalized cylindrical coordinate method; the measurement of the deviation of tooth profile of a non-linear worm .

这些测量包括：①基于广义极坐标法的剃齿刀齿廓误差测量，以及采用&曲率法&自动识别界点的剃齿刀螺旋线误差的测量；②修形滚刀的齿廓测量，以及基于广义圆柱坐标法的滚刀啮合误差的测量；③非线性蜗杆的齿廓误差测量。

The region where it produces two-stream instability is encircles by three boundaries: the outer open field lines, the nearest distance where the instability could take place (corresponding the charactistical frequence is equal to the plasma frequence), and the largest distance where the instability could take place along field lines.

可以发生双流不稳的区域是由三个边界面围成的：一是最外的开场线。一是不稳定性可以发生的最近距离(对应于曲率光子特征频率等于等离子体频率的地方)，最后是沿磁力线能够激发起双流不稳性的最大距离。

According to the basic equations derived under the two assumptions by Harold Lauffer—(1) the energy head of every point of a vertical section remains constant,(2) the flow lines are concentric circular arcs,this paper qives a comprehensive deduction of curvature effect in the characteristics of free overflow of round-crested spillway.118 runs of experiments of three round-crested spillway models of different size have been conducted by the author.

本文根据劳弗尔氏在两项假定[(1)垂直测线上各点所含能量为常数，(2)流线呈同心圆弧]下所导得的基本公式，作了详细的补充引伸，得出圆顶壩自由溢流时各项水力特性中的曲率影响计算公式。作者曾进行了大、中、小三个圆顶壩模型的试验共118组，试验成果基本上和导得的计算公式相合致。文中并根据试验资料制定了一些经验公式，应用时可更简便。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。