透镜

Achromatic doublets are far superior to simple lenses because they are corrected for two color lines, specifically C 656.27nm and F 486.13nm.

消色差双合透镜的优势远远超过简单的透镜，因为有两条色彩线，特别是C 656.27nm和F 486.13nm。

Use magnetic field lens again, two kinds of electron lens elaborate respectively below form and principle.

又用磁场透镜，下面分别阐述两种电子透镜的构成和原理。

Electron lens can be formed by electric field, also can form by magnetic field, in be being used actually, same picture tube uses electric field lens already.

电子透镜可由电场构成，也可由磁场构成，实际使用中，同一显像管既用电场透镜。

Errors in the machining of the objective lens in an electron microscope may result in aberrations which prevent the realization of the theoretically possible resolving power of the instrument.

高分辨本領电子光学仪器要求电子透镜具有理想的旋轉对称性。但是实际的电子透镜存在着非旋轉对称的缺陷；其中极端头的椭圓畸变影响最为严重。

To make picture clear, the electron beam that must come out to be being hit from electron gun undertakes focusing is handled, let electron beam pass electron lens, be opposite with optical lens of beam of light collect action likeness, the electron beam assemble that opens scattering rises, get on fluorescent screen one shines again small spot, add the effect of scanning circuit, ability shows clear picture.

为了使图像清楚，必须对从电子枪打出来的电子束进行聚焦处理，让电子束通过电子透镜，和光学透镜对光束的聚集功能相似，把散射开的电子束会聚起来，在荧光屏上得到一个又亮又小的光点，加上扫描电路的功能，才能显示清楚的图像。

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。

It is found from the analytical expression that the truncation parameter, which is defined as the ratio between the waist of the Gaussian beam and the radius of the lens, has an important effect on the diffraction field distribution of the lens.

应用这个表达式研究了截断参数（透镜的半径与高斯光束束腰半径的比值）对透镜衍射场分布的影响。

The second focal length of the lense is independent of the incident kinetic energy of the electron at the first order approximation.

电子在整个系统中的轨迹，文中并讨论透镜焦点与电子入射位置的关系及透镜的鉴别率。

The lens telescope, or refractor, was vastly improved when it became possible to manufacture high-quality lenses made from flint glass

透镜望远镜，或称折射望远镜，在人们能够制造出高质量的火石玻璃透镜以后得到了很大的改进。

The lens telescope, or refractor, was vastly improved when it became possible to manufacture high-quality lens es made from flint glass

透镜望远镜，或称折射望远镜，在人们能够制造出高质量的火石玻璃透镜以后得到了很大的改进。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。