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
- 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 - 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。 - 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。 - 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。 - 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 matric characteristics and convergences on F-number space
F数空间的度量特征及收敛性 - 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 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。 - 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 F is a number field or a infinite field.
F是一个数域无限域。