聚焦

The good characteristics of the deflection system of electron gun can be obtained by optimizing the velocity and the location of emitting electron beam and by the aclinic emission of the electron beam, that can be achieved by making the end of the anode and the middle part of the cathode level.

研究结果表明：电子枪阳极板端点与阴极灯丝中心点保持水平可满足电子水平出射；非均匀分布的磁场对e型电子枪中电子束具有良好的聚焦作用；所设计的偏转聚焦系统在电子束流为50~100 mA时，束斑小于3 mm。

In theory, firstly, the numerical simulation methods, such as the boundary element method, the finite difference method and the finite element method, were utilized to calculate the distribution of electric field intensity and potential of the electron-gun system, the focusing system and the whole equipment, respectively. Then, the trajectories of the electron-beam were traced by using of the Runge-Kutta method and the Monte-Carlo method associatively. The point spread function was also calculated.

在理论分析中，先后采用边界元方法、差分方法、有限元方法等科学数值计算方法，编制程序，对X射线源的电子枪发射系统、聚焦系统以及发射系统与聚焦系统的组合系统等的电场分布进行了严格的计算，在准确求得各系统电场内各个剖分点的电场场强、偏导数等参量的基础上，采用蒙特-卡罗模拟方法和不等距龙格-库塔方法相结合，追踪由LaB_6单晶阴极表面发射出的大量电子束在电场内的运动轨迹，求出点扩展函数，并根据点扩展函数的优劣，反复调节、大量计算对比，挑选出X射线源最佳的电极结构及其组合。

Numerical calculations show that when azimuthally asymmetric space harmonics increases, the start oscillation length decreases, and that it is possible to increase the start oscillation length by tailoring magnetic field's amplitude and its period.

四、在抑制返波振荡的方法中，改变聚焦磁场是一种比较好的方法，因为改变聚焦磁场几乎不会改变前向波的互作用条件，而会改变返波的互作用条件，因而既可以对返波振荡进行很好的抑制，又有利于提高效率。

It shows that it is possible to increase the start oscillation length by tailoring magnetic field's amplitude and its period without changing the synchronous condition of the fundamental wave; in the meantime, when there are two or more azimuthally asymmetric space harmonics in the high power broad-band helix TWTtraveling wave tu...

与此同时，对起振长度、初始非同步速度参量随皮尔斯增益参量、空间电荷参量、损耗参量等的变化，以及在超宽带行波管中当存在两个或多个角向非对称空间谐波时，起振长度、初始非同步速度参量随周期永久聚焦磁场的变化进行了研究。优化设计聚焦磁场、电子注和螺旋线慢波系统的参量可以对螺旋线行波管的稳定性分析提供必要的依据。

It shows that it is possible to increase the start oscillation length by tailoring magnetic field's amplitude and its period without changing the synchronous condition of the fundamental wave;in the meantime, when there are two or more azimuthally asymmetric space harmonics in the high power broad-band helix TWT, the influences of the Pierce's gain parameter, space charge parameter, and loss parameter on the start oscillation length and real starting asynchronous velocity parameter are also analyzed.

研究结果表明：改变聚焦磁场的幅值或周期来增加起振长度是可能的，而且不会改变基波的互作用条件。与此同时，对起振长度、初始非同步速度参量随皮尔斯增益参量、空间电荷参量、损耗参量等的变化，以及在超宽带行波管中当存在两个或多个角向非对称空间谐波时，起振长度、初始非同步速度参量随周期永久聚焦磁场的变化进行了研究。

The beam conversional properties of Gaussian beams through a telescope-lens system were deduced based on parameter q and ABCD law.

运用q参数和ABCD定律，推导了高斯光束经望远镜和薄聚焦透镜组合系统的聚焦特性的变化规律，并对其进行了数值模拟计算。

An IPGphor unit with immobile pH gradient strips was used in and the Ettan DALT Ⅱ system under constant power and temperature in SDS-PAGE. The 2-D gel was stained by both methods of coomassie blue and silver.

第一向采用固定pH值梯度胶条在IPGphor等电聚焦仪上进行等电聚焦，第二向在恒功率且恒温条件下于Ettan-DALTⅡ高通量电泳仪上进行SDS-PAGE电泳，以银染和考马斯亮蓝两种方法染色。

An IPGphorTM unit with immobile pH gradient strips was used in and the EttanTM DALT Ⅱ system under constant power and temperature in SDS-PAGE. The 2-D gel was stained by both methods of coomassie blue and silver.

第一向采用固定pH值梯度胶条在IPGphorTM等电聚焦仪上进行等电聚焦，第二向在恒功率且恒温条件下于Ettan-DALTTMⅡ高通量电泳仪上进行SDS-PAGE电泳，以银染和考马斯亮蓝两种方法染色。

In order to analyze experimentally the back-scattering micro-spectrum difference between human normal stomach epithetic cell and the cancerous cell to provide optical technique for clinical checking,a micro-spectral measurement setup for checking cell was established based on fiber confocal microscopically imaging technique combined with cell light scattering theory. It could provide micro-imaging and micro-medical spectral information simultaneously.

为了在实验上分析人正常胃上皮细胞与癌变细胞的显微后向散射光谱的区别，为临床医学检测提供实验依据，在光纤共聚焦显微成像技术基础上，结合细胞散射理论，建立了一套基于光纤共聚焦的细胞检测显微光谱分析装置，能够同时获取细胞显微图像和显微光谱医学信息。

Methods The operating astral lamp employs specially-designed LED as the point light source to focalize lights into a beam for operating illumination,and IC is used as the control circuit to manipulate the brightness, focusing, running detecting, alarming, partially auto-repairing and exchanging between AC and DC.

用特定的发光二极管作手术无影灯的点光源，聚焦形成手术照明光束，用单片机IC作控制电路控制无影灯的亮度、聚焦、运行状态检测、报警和部分自动修复等。

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。。。。