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
- 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。 - 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 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 F is a number field or a infinite field.
F是一个数域无限域。 - The fill factor and F number of refractive microlens array fabricated by melting photoresist are increased by reducing developing time.
采用缩短显影时间法改善了光刻胶热熔法制作微透镜阵列的工艺，提高了折射型微透镜阵列的F数（F）与填充因子。 - 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。 - 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 - 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。 - 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。