阿基米德螺旋

Volume of various geometric figures, applied geometry to hydrostatics and

巧装置，如阿基米德螺旋泵，并发现了浮力定理

In the paper, on the basis of aggregation of previous studies, the development of optical technology and development trends at home and abroad are introduced, the principle of Fresnel lens is summarized. In accordance with its principle, circle equidistant steps Fresnel lens design is described. And on this basis, based on Fresnel design, also based on a continuous upward spiral of the plane curve concept, incidence surface and the backlight is set up to greet Archimedes - Fresnel lens design formula and the Second parabolic type Fresnel lens design formula, and on this basis, the advantages and disadvantages of the three designs is discussed.

本文在充分了解非球面光学技术在国内外的发展状况和趋势的基础上，同时从菲涅尔透镜的光学原理出发，并根据它的工作原理推导了圆环等距菲涅尔透镜的设计步骤，并在此基础上依据菲涅尔的设计思想，同时依据平面曲线的连续又呈螺旋的构思，推导出了迎光面和背光面阿基米德型菲涅尔透镜的设计公式和二次抛物面型菲涅尔透镜的设计公式，并在此基础上讨论了这三种设计各自的优缺点。

An assessment of hydropower potential and environmental impact is vital to a decision whether it is feasible and valuable to reinstall a waterwheel, a turbine or an Archimedian screw for Gordleton Mill on the Avon Water, New Forest District, England.

摘 要：水能和环境影响的评估，对于判别英格兰新福里斯特区埃文河Gordleton磨坊重新安装一台改良水车或一台水轮机或一台阿基米德式螺旋水轮机的可行性和经济性是至关重要的。

Archimedes (circa 287-212 B.C.)Famous for Archimedes' screw, a water pump still used in Africa, he is said to have leaped out of his bath, yelling "Eureka!"

在非洲，阿基米德著名的螺旋杆，也就是一种水泵至今还在使用。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷