f number
英 [ˈef nʌmbə(r)]
美 [ˈef nʌmbər]
焦距值；光圈数
英英释义
noun
- the ratio of the focal length to the diameter of a (camera) lens system
双语例句
- The results show that under increasing pressure the band occupation numbers change, with s and p electron number gradually transferring to d and f electron number.
结果表明，随着压强的增加，能带电子占据数发生变化，s分波和P分波电荷逐步向d分波和f分波电荷转移；电声矩阵元中p（？） - The F number was 1. The lens group consisted of 3 elements.
设计的物镜F数为1，三片式结构。 - The degree of a face f in G ( written r ( f)) is the number of edges of G incident with f, each cut edges counting as two edges.
一个面所关联的边的个数（割边要计算两次），被称为面的度，用r（f）表示。 - A computing method of f he number of lateral sides and the coordinates of vertices of a mixture CONVEX-POLYHEDRON having lower and upper bounds
兼有上、下界约束混料凸多面体的面数与顶点坐标的一种计算方法 - The F number standard for concrete floor developed by american concrete Institute and Canadian Standards Association is superior to the standard known as the gep under a straight edge. This paper briefly introduces its significance and application metod on site.
介绍了美国混凝土学会和加拿大标准学会的F数标准，以及使用该混凝土地面平整度和水平度标准的现实意义和现场测量方法。 - The effective focal length and back working distance of the system are respectively 100 mm and 113 mm, while the F number is 2.0.The system which has only three lenses contains two negative germanium lenses and one positive zinc selenide lens.
该系统全视场为14°，有效焦距为100mm，后工作距为113mm，F/2.0.系统采用锗和硒化锌两种材料，为三片镜结构。 - The optical performance of small F number diffractive microlens arrays little voice
小F数衍射微透镜阵列光学性能研究 - The method of the curve fitting with piecewise polynomials is used to derive an averaged experimental relationship f ( R) between the number of times in a year Ck and the sunspot relative number Rk ( k is the order of the years from 1980 to 1979).
用曲线分段拟合法求出地磁扰动年次数Ck与黑子相对数Rk之间的经验的平均关系f（R）； - The matric characteristics and convergences on F-number space
F数空间的度量特征及收敛性 - You can really think of it as the sum of the values of f everywhere divided by the number of points everywhere.
可以认为这是所有点处f值的和，再除以所有点的数。