抛物面

The main advantage of reflecting telescope there is no chromatic aberration, when the objective lens when using parabolic, but also can eliminate spherical aberration.

反射望远镜的主要优点是不存在色差，当物镜采用抛物面时，还可消去球差。

A numerical control method of 4-axis side milling to generate the ruled surface such as the vane wheel was presented.

最后，通过数控实验验证了该方法的可行性，并结合了径流式叶轮机械轴—径型叶轮抛物面叶片的成型设计计算方法，使设计计算和加工计算更方便，加工效率更高。

When Japan launches a 33-foot radio dish into orbit next year the world's first space radio telescope will use the Very Long Baseline Array's correlator in Socorro as its "brain," and will tie in with the array for joint observations.

日本明年将把33英尺的射电抛物面天线送入轨道，此时世界第一台空间射电望远镜，将索科罗德的甚长基线阵列处理机作为其"大脑"，与该阵列结合为联合天文台。

Next year will be on coal, ore spodumene, bromamine, tellutide and other energy resources; foudamental acid oil plants of raw materials, tetaining solar parabolic reflector as environmental protection equipment and parts of the implementation of a lower rate of tax on imported tentative; continue to crude oil, wood pulp, ferrolloy, steel billet, part of the assets'protection, such as energy consumption on the environmental impact of large exports tentative tax rate.

明年将对煤炭、锂辉石矿、溴、碲等能源资源类产品，植物酸性油等基础性原材料，槽式太阳能抛物面反射镜等有利于环境保护的设备及零部件实施较低的进口暂定税率；继续对原油、木浆、铁合金、钢坯、部分钢材等资源性、生产能耗高、对环境影响大的产品实施出口暂定税率。

A progress based on fine grinding and computer controlled optical surfacing are presented in this article.

详细介绍了基于超精密磨削技术和小工具数控抛光技术加工离轴抛物面镜的加工过程。

, c a parabolic umbilic, if RA consists of three lines, two of which are coincident see Fig.

c一抛物面中心的，如果镭包括三条线，二，其中是一致的看见。

F Para-bolic umbilic.

f抛物面中心的。

The reason for this is its very narrow vertical radiation angle.

正如上图所示，3D角反射器天线在抛物面F/D为0.9或更高时有很高的效率。

The VisionStation has a large parabolic shell that is used to display the image projected by the wide-angle lens.

VisionStation有一个大型抛物面薄壳状显示器，用来显示广角镜头投射的图像。

The problems include Catmull-Clark subdivision surfaces can"t precisely represent standard conicoid except paraboloid, and it can"t modify the shape of limited surfaces when the original control mesh be given.

Catmull-Clark细分曲面无法精确表示除抛物面外的常规二次曲面；在给定初始控制网格的情况下，难以调整所生成曲面的形状等。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。