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 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。
• 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。
• A modified first-derivative based QRST detection algorithm as well as a proposed adaptive f wave number detection algorithm was utilized in the method, and new conditions was set for AF detection.
  该方法应用了改进的一阶差分QRST检测算法和提出的自适应f波波数检测算法，并设置了新的房颤检测条件。
• 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。
• Papers during the theoretical analysis, but also cited a number of companies in the procurement of F found in a number of practical issues and give the corresponding solution to the problem.
  论文在进行理论分析的同时，也列举了一些F公司在采购工作中发现的一些实际问题并给出相应解决问题的办法。
• The matric characteristics and convergences on F-number space
  F数空间的度量特征及收敛性
• 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
• 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。
• 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。
• 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。