focal ratio

英 [ˈfəʊkl ˈreɪʃiəʊ]

美 [ˈfoʊkl ˈreɪʃioʊ]

网络  焦比; 焦距比; 焦比大

英英释义

noun

• the ratio of the focal length to the diameter of a (camera) lens system
  Synonym:f numberstop numberspeed

双语例句

• The focal ratio of the Cassegrain system for the telescope is F/ 10 and the plate scale is 20 ″/ mm.
  该望远镜卡焦焦比为F/10，底片比例尺为20〃/mm，无畸变象场约为1平方度天区。
• Determination of focal mechanism using SH to p amplitude ratio
  用SH波和P波振幅比确定震源机制解
• The results show that the focal, field and remote precursory anomalies are of the following characteristics: The spatial distribution of anomalies is inhomogeneous, the distribution of anomalous monitoring stations of focal precursors is concentrated, and the anomaly ratio can reach 90%;
  结果表明，源、场、远兆异常有如下特征：异常空间展布不均，源兆空间内异常监测点展布“密集”、异常比例可达90%；
• It has many advantages to determine the focal mechanism by using SH and P wave amplitude ratio, but requires highly for the distribution of stations.
  用SH波和P波振幅比测定地震震源机制具有诸多优点，但它对台站布局要求较高。
• Using geometry theory and the Monte Carlo method study its 'geometric optical characteristics and focal plane density distribution, and consider influence of different error on geometric concentrating ratio and the flux density distribution.
  利用几何学原理和MonteCarlo方法研究新型多平面太阳能聚光器的几何光学特征及焦平面能流密度分布，分析不同综合误差对几何聚光比及能流密度分布的影响。
• The application of focal mechanism determinations of moderate-small earthquakes in Yunnan Province using the first motion and amplitude ratio of P and S wave
  用P波、S波初动和振幅比计算中小地震震源机制在云南地区的应用
• Conclusion The neuroprotective effects of aspirin on focal cerebral ischemia-reperfusion injury in rats for 72 h might be attributed to its effects by anti-apoptosis, increasing the ratio of Bcl-2/ Bax, inhibiting the activity of CaN, and improving the energy metabolism.
  结论阿司匹林对脑缺血/再灌损伤72h有明显保护作用，其机制可能与抗凋亡、提高Bcl2/Bax、改善能量代谢及对钙调神经磷酸酶的影响有关。
• Study of the Tests of Large-aperture and Fast Focal Ratio Convex Hyperboloid Mirrors with a "Stitching" Method
  大口径快焦比凸双曲面拼接检测方法研究
• Given the laser intensity, the optimum focal size increases with the pulse width, and the ratio of the optimum focal size to the pulse width is fixed.
  在相同激光强度下，电子能量增益的最佳焦斑大小随脉冲宽度的增大而增大，但最佳焦斑大小与脉冲宽度的比值基本上是不变的。
• Focal point at the ratio of transmission calculating, every gear wheel torsion of the differential gear wheel system distributing and the Accident analysis and scheme of transforming for the stretcher straightener, We have carried on the detailed discussion to study.
  本文重点拉弯矫正机差速器传动系统的对传动比及效率计算、差速齿轮系统各齿轮扭矩分配、齿轮承载能力计算，气垫炉拉弯矫正机设备故障分析及改造方案进行了详细的讨论研究。