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

• 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。
• 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。
• 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 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。
• 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
• 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 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（？）
• Improving the Fill Factor and F Number of Refractive Microlens Array by Reducing Developing Time
  通过缩短显影时间提高微透镜阵列的填充因子与F数
• The author presents a method of calculating the error of location and analyses the relationship between the error of location and the frequency difference of double-frequency grating ( or the amount of shear) and F number of the system.
  文中提出了计算定焦误差的方法，分析了定焦误差与双频光栅的频率差（或剪切量）及系统的F数之间的关系。
• 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。