曲率线

And the induced normal curvature along the normal of contact line between the worm and the planet is obtained. The algebraic expression of the induced normal curvature at the top point of the ball-tooth is given.

另外，对行星轮与环面蜗杆沿接触线法线方向的诱导法曲率进行了求解和分析，给出了诱导法曲率在球齿齿面顶点时的代数式显式表达。

This paper presentes the spherometer of designed with the principle of Archimedes spiral, it has main advantage: both continuity measurement and direct reading to curvature radius of sphere, over against some classical instruments requested the conversion of the measuring result.

本文提出的应用阿基米德螺线原理设计的球面曲率计，克服了某些经典仪器需间接换算测量结果的缺陷，其主要优点是能直接读出所测球面的曲率半径和进行连续性测量，在使用上极为方便。

In addition, we made account for the selection of inverted bending curvature of pipe axis and the length of equal curvature region, and pointed out that we can only equalize the curvature in the equal region and carrying out straightening really is in the region of unequal curvature. This is the development and perfect of bending straightening theory and this method can spread to bar straightening machine.

此外，还对反弯曲线曲率和等曲率区长度的选取作了说明，指出在等曲率弯曲区只能使曲率均匀化，而真正实现矫正是在后部的非等曲率弯曲区，这是对矫正理论的深入和完善，并且这一研究方法也可推广到棒材矫正机。

First, a special normal transversal at the initial point is constructed and a second-order Taylor's algorithm is used to trace the projections along the aforementioned normal transversal. A curvature based method for controlling iteration step is further proposed by projecting the given point onto the curvature circle of the normal transversal at the initial point. Finally gradient based method for correcting iteration errors is put forward.

首先构造初始点处的一条特殊的法截线，并给出沿着该法截线追踪投影点的二阶泰勒迭代方法；然后将给定点向初始点处的法截线的曲率圆作投影，提出基于曲率的步长控制策略，在此基础上给出了基于梯度的迭代误差矫正方法。

In this paper, a "rigid bar relative movement model" was established to illustrate the traces of the helices in wire ropes. The angular speed of a moving particle of the model was relatives to curvature tensor to derive the curvature components and torsion of helices in multi-layer wire ropes. According to long and thin rod theory of Love and Yen-Chen's theoretical model considered the contact force and frictional force, the force-deformation or force-strain relative of wire in curved wire ropes subjected axial force is derived from the curvature components and curvature increment.

本研究改以刚杆相对运动模型，直接描述钢索中钢绞线轨迹，并且透过角速度类比曲率张量之概念，推导圆弧型多层钢索内部之钢铰线之曲率分量与扭率；之后再依据Love的细长杆理论，辅以Yen-Chen在考虑接触力及摩擦力下所修正之理论模型，以曲率及曲率增量来探讨圆弧型钢索受静态荷重作用下，钢绞线之受力与变形或应变关系。

Through studying some fundamental properties of the curved surface in differential geometry , a method of linear feature extraction based on differential geometry is introduced.

通过研究微分几何理论中曲面的一些基本性质，本文介绍了一种基于微分几何的线状地物提取方法，首先在局部区域内拟合一个二次曲面函数，然后通过该函数来估算灰度曲面的梯度和曲率，设定合适的梯度和曲率阈值来检测线状地物，最后进行后处理，消除许多噪声颗粒及小块区域。

A method for identifying the damage, using the influence line curvature of deflection differential values at a point before and after the damage is proposed, that is, when the moving load is in the area without the damage, the influence line curvature is zero, however when the moving load is in the area with the damage, the influence line curvature evidently increases and has the relationship with the positions of the damage points and the rigidity of the beam before and after the damage.

提出利用损伤前、后某一点的挠度差值影响线曲率来识别损伤的方法，即当移动荷载位于无损区域时，挠度差值影响线曲率为0，当移动荷载位于有损区域时，挠度差值影响线曲率明显增大，且与损伤点的位置、损伤前后的刚度有关。

The first and second derivatives of the coordinates of a cam profile are calculated using numerical differentiation method,and substituted with curvature radius formulas in calculus,thus obtaining its curvature radius.

应用数值微分法计算凸轮廓线坐标的一、二阶导数，代入微积分学中曲率半径公式，即得凸轮廓线的曲率半径。

The parameters are :① reservoir effective thickness;② reservoir porosity;③ reservoir volume efficiency;④ fair pay ′ s reservoir volume efficiency;⑤ distance to the fault;⑥ reciprocal of the square root of the distance to the fault ）;⑦ apparent fold strength coefficient;⑧ maximum principal curvature of structural plane;⑨ transversal section line curvature;and ⑩ longitudinal section line curvature.

摘 要 介绍了气井产能的确定方法及地质参数的选择与计算方法：采用初始二项式无阻流量、稳定产量及初始采气指数作为气井产能评价的指标；10项参数分别是①储层有效厚度；②储层孔隙度；③储容系数；④好储层的储容系数；⑤与断层的距离；⑥与断层距离开方的倒数；⑦视褶皱强度系数；⑧构造面最大主曲率；⑨横向剖面线曲率；⑩纵向剖面线曲率。

Curvature is the result of geometric structure in image; a new third order partial differential equation is proposed which transports curvature information along isophotes. The third order POE is morphologically invariant. Helmholtz vorticity equation which annihilates vorticity and third order POE which forward transports curvature information are coupled to be a new model.

曲率是图像几何特征作用的结果，本文提出沿等照度线方向传输曲率信息的三阶形态学不变偏微分方程，并将抑制涡量的无粘亥姆霍兹方程和正向传输曲率信息的三阶偏微分方程耦合。

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。