曲率

By means of uniting geometry with algebra, the arc length, tangent line, cotangent space and curvature of curve in four dimensional space are investigated, and the corresponding calculation formula in each cases are given.

用形数结合的观点研究了四维空间中曲线的弧长、切线、法空间和曲率问题，并给出了其计算公式。

This paper presents a new method——using mean radius of curvature to find the substitutive arc of Archimedes spiral,with which better precision can be obtained and the calculating formulas are very simple.

提出了一种用平均曲率半径法求阿基米德螺旋线的代用圆弧的新方法，其计算公式简单，并可得到较高的精度。

Spherometer ; Theory equation of sphere curvature radius ; Principle of Archimedes spiral.

球面曲率计；理论球径公式；阿基米德螺线原理

The present elastic-plastic model considers the summits of asperities with different radius and interaction between neighboring asperities when there is enough deformation for an asperity, so it is more practical than previous models, and is also a guide for further research of tribology models related to fractal characteristics.

建立的模型考虑各个微凸体具有不同的峰顶曲率半径，当变形足够大时考虑微凸体间的相互作用，因而较前人建立的模型更符合工程实际，同时也对与分形特征相关的摩擦学模型的进一步研究具有一定的指导作用。

More asperities tend to interact with each other and affect the central contact zone in elastic-plastic contacts as compared with elastic contacts. The change of spacing and radius of asperities and indentation depth would influence the asperity interaction.

同弹性接触相比，在弹塑性接触过程中有更多的邻近粗糙峰对中心接触区发生作用，改变粗糙峰的间距、曲率半径和压下深度都会对其产生影响。

Based on measured surface topography in conjunction with theoretical analysis, the characteristics of surface during wear process are studied, and the asperity density and asperity curvature radius are given for the first time.

本文通过对缸套表面的实测和分析，研究了在磨损前后表面形貌的变化，并首次定量描述了微凸体密度、微凸体曲率半径及其沿高度方向的变化。

This paper reviews whether forward movement of the posterior corneal surface occurred, changes in posterior corneal power and curvature, changes in posterior corneal astigmatism and tilt, changes in posterior corneal asphericity and BFS after the surgery.

本文综述了准分子激光屈光性手术后角膜后表面是否发生前移改变、角膜后表面屈光力、曲率、散光度、轴度、非球面特性以及最适球面等是否发生改变的研究进展。

This paper reported a new method using tangential curvature to establish a mathematical model of the anterior cornea and an analysis of the regularity of the distribution of the asphericity Q. The curvature in the horizontal meridians is a prolate ellipse. The curvature in the vertical meridians is an oblate ellipse. The curvature of the horizontal meridians is important for anterior corneal asphericity.

本研究分析了运用正切曲率半径值建立人眼前表面角膜数学模型的科学性，显示角膜前表面水平子午线方向非球面性趋向于长椭圆，垂直子午线方向非球面性趋向于扁椭圆，说明人眼角膜的非球面性特性主要由水平子午线实现。

The Dirt shader is an excellent way of using information gathered from the surface itself, in this case the amount of curvature at a given point, to control the texture associated with the surface

DIRT材质是一个极好的方法去使用从表面上得到的信息，在这个例子里，在一个给定点会有一定数量的曲率值，去控制在这个表面上的纹理关联。

Metric tensor ; curvature tensor ; asymptotic analysis ; tensor analysis

度量张量；曲率张量；渐近分析；张量分析

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐