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
  Synonym:focal ratiostop numberspeed

双语例句

• F any product on which the serial number has been removed, defaced or modified.
  任何产品上的序列号已被删除，涂改或修改。
• 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 ray tracing method and vectorial Stratton Chu diffraction Integration are applied in the analysis of the imaging performance over the focal planes of hyperbolic lens and reverse microscope lens system with small F number.
  采用射线追迹结合StrattonChu矢量衍射积分公式的方法分析计算了小F数双曲透镜和倒置显微镜的焦面成像特性。
• 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。
• 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。
• If diffractive efficiency is not considered, the numerical results show that larger f number microlens has smaller divergence angle.
  同时，如果不考虑微透镜的衍射效率，当球面折射微透镜的F数越大，高斯光束经过准直变换后的远场发散角越小。
• 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 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。
• 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 injection rate is the average interarrival time, the multicast size is the number of destination nodes, and the message length f is the number of flits in a message.
  注射率的平均间隔时间，多目传播大小是指目的节点的数量，消息长度f是一个消息的字节流的数量。