查询词典 plane curve

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。

Consider a plane curve with parametric equation.

设平面曲线的参数方程为，则曲率为

Please tell me what the plane curve means.

请告诉我这条平面曲线是什么意思。

On the basis of analysis of geometric feature of plane curve,an algorithm for matching contours is introduced in this paper.

在分析平面曲线的几何特性的基础上，提出了一种快速有效的轮廓曲线匹配算法。

This is a plane curve .

这是一条平面曲线。

If the plane curve is given by ,where is continuous on ,then

如果曲线是由极坐标方程所给出的，其中在上连续，则

Symmetry of plane curve is important to function research.

平面曲线的对称性对于函数研究具有重要意义。

Taking plane curve machining for example, the motion schemes of machine tools with two freedoms are presented.

以平面曲线加工为例，给出了所有两自由度机床的运动方案。

In this paper, the program for earthquake response analysis of Girder Bridge is established, and the calculation and analysis of the bridges on plane curve are with that program.

本文用自编的梁桥地震响应分析程序，对此类桥梁进行了计算和分析，总结了此类桥梁的地震响应特点，提出了抗震设计的一些建议。

Road design, calculation of the plane curve model categories, which translate such relaxation curves.

道路设计中，平面曲线计算的模型类，该类中可计算缓和曲线。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。