相对孔径

The design of four-mirror anastigmat was analyzed, then a system with effective focal length of 1 200 mm and field of view of 0.8°×0.8° was designed , total length and f-number are 300 mm and F/6,respectively.The system has advantages of long focal length, relative short physical size and excellent ability in restraining stray lights.

分析了离轴四反的设计步骤，设计了一个焦距为1 200 mm，视场为0.8°×0.8°，相对孔径为F/6的光学系统，系统总长只有300 mm，并达到很好的光学性能，具有长焦距、小尺寸、良好的杂散光抑制能力等特点。

The relation between the spectrographic aperture ratio and elliptical eccentricity, spectral angle is also analyzed according to the elliptical geometry, it will decrease when the x-ray wavelength increases.

根据椭圆的几何关系，研究了光谱相对孔径与椭圆的离心率和谱线探测角之间的关系，它随X射线波长增大而减小。

The lens system adopted the Reverse-Telephoto configuration which had an effective focal length of 5.5mm,an F-number of F/4 ,a field of view of 175°,and a working wavelength in the range of visible spectrum.

系统焦距为5.5mm，相对孔径为1/4，全视场角175°，光谱范围为可见光波段，采用了3组10片的反远距型结构。

This paper presented an optical system of star sensor. The lens system was a complicated double- Gauss configuration which had an effective focal length of 51 mm, an F-number of F/1.1, a field of view of 21°×21°(2ω=30°),and a working wavelength rang of 0.5~0.85 μm.

介绍了一种用于卫星姿态控制的星敏感器光学系统，该光学系统焦距为51 mm，相对孔径为1/1.1，视场角为21°×21°（圆视场2ω＝30°），光谱范围为0.5～0.85 μm，采用了复杂化双高斯结构。

A R-C system with foci of 2 m and f-number F/4 was taken for an example, the principles of stray light eliminating and evalutiong in reflective optical system was put forward. Lens hood in the main mirror, lens hood outside and window shade, lens hood in the secondly mirror were designed by CAD modeling.

以焦距为2 m，相对孔径为1/4的R-C系统为例，介绍了利用计算机仿真技术进行消杂散光设计和评价的原理，结合CAD建模进行了主镜内遮光罩、外遮光筒、次镜百叶窗式遮光罩的设计。

In my study, we use a 4F acoustic lens which f-number is 1.3 to set up a photoacoustic imaging system. With same axial and lateral magnification, 3D photoacoustic imaging system with 4F acoustic lens can detect photoacoustic signal distribution on object plane in real-time, and get the different axial distance signal to show the 3D photoacoustic image by different signal receiving time.

本研究采用相对孔径为1.3的4F声透镜，设计三维光声影像系统，利用4F声透镜景深范围内之轴向与横向放大倍率相等，即时性的重现物平面所发出的同调性光声讯号分布，并利用不同的接收时间来呈现不同深度距离的讯号成像，取得物平面上受测物的三维光声影像。

The merit of the invention are: 1 adopting free curved surface imaging method , three part reflection type Zernike polynomial free curved surface forms short focal distance bigger, relative apertures bigger fields of view angle imaging , rectifying optical aberration much better and its structure is simple; 2 adopting the reflection structure without optical lens, has removed the effect of various chromatic aberration , guarantee the imaging articulation; 3 adopt the design of short focal distance big fields of view angle, focal distance 8 - 15 mm, field of view angles 100 -135 degree, having 120 times multiplications under 250 mm imaging distance, having ultra-thin characteristic property; 4 adopting big relative apertures design ,the relative aperture is 2.0-2.4, having improved the illuminance of flat surface; 5 adopting image space telecentric imaging method , ensures that the image surface irradiance is homogeneous.

本发明的优点是：1采用自由曲面成像方法，三片反射式Zernike多项式自由曲面形成短焦距大相对孔径大视场角成像，更好地校正像差，结构简单；2采用无透镜形式的反射式结构，消除了各种色差影响，保证成像清晰度；3采用短焦距大视场角设计，焦距8～15mm，具有100～135度的视场角，在250mm成像距离下有120倍的放大倍数，具有超薄特性；4采用大相对孔径设计，相对孔径为2.0～2.4，提高像平面上的光照度；5采用像方远心成像方法，保证像面辐照度均匀。

Optical system design for lens with relative aperture of 1∶1［J］.

相对孔径为1：1镜头的光学系统设计［J］。

Optical system design for lens with relative aperture 1∶1.

相对孔径为1∶1镜头的光学系统设计。

A spectral camera lens with the relative aperture of 1∶1 is introduced.

介绍一种相对孔径为1：1的光谱摄像镜头。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了