查询词典 aperture of lens

The unsuspecting photographer focuses with the lens wide open to place the circle of least confusion at the sensor position b, and, taking the actual picture at a reduced aperture, he is unaware of the ensuing focus shift that prevents him from getting the best out of the lens.

一个经常使用全孔径来拍摄的摄影师会毫不犹豫地把胶片放在B点，但是如果他不改变胶片的位置，当他使用小光圈的时候，事实上，他就不可能充分利用这个镜头拍到最好的照片了。

First,the planar waveguide models for Rotman lens and its feed lines which incorporate the dispersion effect with frequencies are set up.Then the aperture electric fields at lens ports are expanded by appropriate waveguide mode functions and substituted into the contour integral equation.The multimode scattering matrix of the lens can be acquired by solving the contour integral equation by using Galerkin method.

首先建立了考虑色散效应的透镜的等效平板波导模型，然后选择适当的波导模式函数展开透镜端口上的场，并利用Galerkin法求解其边缘上电场满足的轮廓积分方程即可得到透镜的多模式散射参数。

F-number: The figures marked on the lens collar to indicate the size of the lens aperture in relation to its focal length.

光圈值：刻划在镜头上用来表示镜头孔径与焦距关系的比值。

The ratio of the focal length of a lens or lens system to the effective diameter of its aperture.

光学仪器的目镜上的细线、圆点、十字型细线或金属丝组成的系统。

The latest experimental results of the focusing perfermance of the compound high-energy X-ray lens is designed with PMMA with the parameters of 40 plano-concave elementary lenses positioned in line with axial symmetry, 200 μm radius of the concave surface, 0.15 nm working wavelength, 0.5 mm geometrical aperture and 8 mm length of the compound lens and 1.3 m focus length, are briefly introduced.

报道了这种新型X射线光学元件聚焦性能的最新实验结果。设计的高能X射线组合透镜为聚甲基丙烯酸甲酯材料，包括40个相同的、顺序排布的平凹折射单元，折射单元的球面半径为200 μm，组合透镜的几何口径约为500 μm，长度约为8 mm，焦距约为1.3 m。简要描述了PMMA材料X射线组合透镜的制作技术和制作过程。并给出了X射线组合透镜聚焦性能测试实验系统和实验条件。

It is found that the bright points distributed regularly adjacent to main facular is spectral distribution on the focal plane of the array of lens when the laser irradiates a hexagonal aperture,rather than what is induced by stray light.

结果表明，主光斑附近规则分布的亮点并不是由杂散光引起的，而是激光辐照六边形光阑，在透镜组焦平面所成的频谱分布。

Based on the expression of diffractive field distribution of the Gaussian beams restricted by a rectangular aperture and focalized by a lens,the relationship between the width of the rectangular aperture and the spot size of the restricted beam,as well as the relationship between the aperture width and the power in the bucket,was numerically calculated with MATLAB.

为了研究矩形光阑边长与透镜像方焦面处光束光斑尺寸以及光斑内所包含功率的关系，根据高斯光束经矩形光阑和透镜变换后在透镜像方焦面的衍射场分布表达式，采用MATLAB进行数值计算的方法，进行了理论分析。

The lens-less pupil works rather like the aperture of a pinhole camera.

这种没有透镜结构的瞳孔更像是针孔相机的孔。

Based on the relationship between the numerical aperture of the objective lens and scale pitch, this study chooses a suitable Plano-convex lenses available on the market, so as to approximate the diameter of the focusing spots to scale pitch. Also, by using the optical path of an optical encoder similar to the nanoscale, the changes in the surface profile of the scale can be measured directly, so as to obtain the two quadrature sinusoidal signals. By counting the zero crossing of these two quadrature sinusoidal signals and calculating the interpolation value of these two quadrature sinusoidal signals, the moving direction and moving displacement value of the scale can be obtained.

研究中再以搭配物镜的数值孔径与尺条间距的关系，选择ㄧ适当的市售平凸透镜，使聚焦光点的直径与尺条的间距相近，并使用相同於奈米级长行程双雷射聚焦读头装置的光路设计，如此将可藉由直接量测尺条的表面轮廓变化，以获得一组正交弦波讯号，继而利用讯号四分割与细分割处理，计算出尺条之移动方向与移动量，研制出一实用性长行程双雷射聚焦读头光学尺。

The original technology is based on the far-field optical but all of them are restricted by Rayleigh diffraction limit.In order to break optical diffraction limit restrictions, people improve recording density in three ways:(1) shorten wavelength of light,(2)increase numerical aperture of the lens N.A.

不过上述储存方式所采用的记录技术皆是在远场光学的领域内，在远场光学的绕射极限下，要持续提升记录密度的方法有三种；(1)缩小光源波长(2)提高透镜的数值孔径

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。