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

• 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。
• This paper analyses colour subcarrier quantization noise in PCM coding of complete television singal. The relationship between quantization noise and sampling frequency ( f s) as well as quantizing bit number ( n) is discussed.
  分析了全电视信号PCM编码色度副载波量化噪声，并讨论了量化噪声与取样频率fs和量化比特数n的关系。
• 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
• Investigation on space optical system of high F number and high resolution
  大F数高分辨率空间望远镜光学系统
• 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
• 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 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 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 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。