曲面

To mathematically characterize the deformation of the middle surface of a shell, the metric tensor and curvature tensor ought to be investigated in detail.

为了从数学角度更好地描述壳体中性曲面如何变形，通过渐近分析和张量分析，给出了当壳体中性曲面发生形变时度量张量和曲率张量改变量的完整表达式。

And if a single curved glass would distort nature, how much more would a pair of them?

何况一片曲面镜就可歪曲自然，那么伽利略的两片曲面镜对自然的歪曲又该多大呢？

Single curved glass would distort nature, how much more would a pair of them?

如果单一的曲面镜会歪曲自然，那么一对曲面镜对自然的歪曲又会多大呢？

Some telescopes do not use a lens at the front. They use a curved mirror at the back. A curved mirror is better than a lens in some ways.

一些望远镜的前部不用透镜，而在后面装上一个曲面镜，曲面镜在某些方面要比透镜好。

This article presents an ideal energy distribution for improving the cutting speed of thin plane glass.

本文透过多曲面反射镜的设计来控制雷射光能量场的分布，使YAG雷射应用於薄板玻璃切割时能加快切割速度，并利用田口法进行多曲面反射镜的优化，使雷射光能量场的分布更接近预期状况。

After obtaining a family of blending curves and surfaces, we construct a new energy smoothing equation for determining the parameters to get the desirable blending curve and surface.

另外，在得到的混合曲线曲面族中构造出了新的更优能量光顺方程，通过设置参数可得到合适的混合曲线曲面。

A developable surface is one that can be made from a flat sheet without any in-plane strains.

可展曲面是一个可以由平板在不发生任何面内应变的条件下弯成的曲面。

In this manner, a developable surface was designed using control planes with Bézier and B-spline basis functions.

基于将可展曲面作为平面单参数族包络面的思想，给出在Bézier和B样条基下可展曲面的参数表示形式。

This method presented in this paper can save a lot of time in drawing the developable surface, increase the productive efficiency and the accuracy of blanking , and can be applied to all dinds of expansion of developable surface, zoom the dimension.

该方法可大大缩短可展曲面展开图的绘制时间，提高生产效率及展开下料精度，适用于各种类型可展曲面的展开，并可进行尺寸缩放等相关操作，具有较好的实用性和经济价值

Furthermore, by the design method that a developable surface is an envelope surface, we give detail analysis of examples about using the same control planes to design developable surfaces.

讨论了所设计可展曲面的特点和几何构造，研究结果表明，所提出的设计方法具有现有曲线设计方法的特征，现有的对于曲线的一些几何构造技术可延伸到可展曲面的设计。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。