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
- In the past design, under the conditions of larger discharge and energy dissipation, flow cavitation number σ f larger than incipient cavitation number σ I of the flood tunnel must be satisfied to avoid cavitation in it.
在以往的设计中，在满足较大的泄量和消能量条件下，通常泄洪洞还要满足σf＞σi，以免发生空化空蚀。 - 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。 - Based on the hydraulically and thermally developing flows, the flow and temperature fields, Nu, f and field synergy number Fc are obtained for different Re and wall temperatures.
模拟以通道入口段的流动和换热为对象，得到了不同Re和不同壁温下的流场和温度场，对流换热的Nu和阻力系数，以及场协同数Fc。 - Study of F Number of Microlenses for Collimation of Laser Diode Arrays
阵列激光微透镜准直器透镜F数的研究 - Methods Testing patients 'pronunciation with of without complete denture and contrast with normal speech sounds. Using USSA to analyes its frequency and parameter number of wave crest ( F) and energy number ( P).
方法对无牙颌患者戴全口义齿前、后与正常对照组进行语音a/i/u的检测并对其共振峰参数频率值（F）、能量值（P）的USSA语音频谱的分析。 - 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。 - 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 - 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 results were correlated in term of j and f as a function of Reynolds number and the geometrical parameters of heat exchangers by multiple linear regression technique.
通过多元线性回归法将实验数据整理为以雷诺数和换热器几何参数为自变量的j和f关联式。