the second-order moment radius of the focal spot depending on intensity distribution and phase distribution of near field is derived, and its clear physical meaning is described.

结果表明：畸变光束的焦斑二阶矩角半径由光束近场波前相位梯度的强度加权均方根值和对数强度梯度的强度加权均方根值决定。

a new method-axial scanning method (asm)-is devised to find the position of the focal spot of polycap-illary x-ray lens.

为了高效準确地确定整体x光透镜焦斑位置，设计了一种新方法：轴向扫描法。

from the result we can see that using this method we can get high accuracy in the focal spot measuring.

设计结果表明，利用旋转椭球面进行大口径取样镜设计可以使焦斑测量具有极高的準确性。

the gauss width of focal spot which is too small results in the sampling error while using ccd as the centroid detecting device of shack-hartmann wavefront sensor(shws) in adaptive optics(ao) system.

自适应光学系统中采用ccd作为哈特曼波前传感器的光斑质心位置探测器时，由于光斑的高斯宽度较小会带来大采样误差。

the x-ray tube focal spot is obtained by convergence of static field on the electron beams.

射线管的焦点是通过静电场对电子束的会聚作用而形成的。

the focal spot sizes can immediately influence picture definition when x-ray machine carry through clairvoyance and photography.

焦点的尺寸大小及聚焦质量直接影响x射线机透视、摄影图像的清晰度；

the phase difference caused by piston error translated with the tiled-grating compressor, the focal spot was affected by both non-integral number of grating space and out-of-plane piston error.

位移偏差引入的相位随着拼接光栅压缩器传递，其对远场焦斑的影响，取决于每片子光栅的非整数倍光栅常数的横向位移偏差和纵向位移偏差的综合作用。

the modulation transfer function(mtf) of x-ray tube focal spot and its size are the main parameters, which can be used to describe the photo function of x-ray tube focal spots.

线管焦点的调制传递函数（mtf）和焦点尺寸是描述x线管焦点成像性能的主要参数。

it shows that the irradiation non-uniformity of focal spot falls down from 14% with la to 3% with ssd and la.

结果表明：焦斑的不均匀性从单独使用透镜列阵时的14%降低到与谱色散平滑结合后的3%；

under the different laser parameters, the electron energy gain depends on the laser intensity, focal spot size and pulse width.

不同激光参鼍条件下，得到了电子的能量增益与激光强度、焦斑大小和脉沖宽度关系。

by infrared thermal imaging techniques in this thesis, the focal spot size and focal length of this dielectric lens antenna are measured.

本论文应用红外热成像技术，对毫米波介质透镜天线的焦斑焦距进行了测量。

the sizes of focal spot and detector aperture are the factors affecting ct image quality.

射线源焦点及探测器孔径大小是导致ct图象降质的主要因素。

there are no evident energy gain when the focal spot size is too big or small.

电子的能量增益有一个最佳焦斑大小。

one of the focal spot of marine ecology is the effects of diatom on copepod reproduction, which decreases copepod egg fecundity and hatching success.

硅藻对桡足类繁殖的影响是近年来海洋生态学的热点问题，主要体现在降低了桡足类的产卵和孵化成功率。

the measurement method and error analysis method of grin lens focal spot diameter in ir wavelength are described.

主要介绍grin透镜在红外波段聚焦光斑直径的测量方法及误差分析。

objective to improve hifu focal spot accuracy.

目的：提高hifu焦斑精度。

the result power spectrum analyses of focal spot show that the smoothing effect is caused by middle and high frequency intensity suppression.

对焦斑点功率谱的分析表明谱色散平滑通过抑制焦斑中高频的频谱强度达到平滑效果。

but the size perpendicular to polarization direction of focal spot with linear polarized beam is always smaller than that of radially polarized beam.

而线偏振光聚焦光斑垂直于偏振方向的直径始终小于径向偏振光聚焦光斑直径。

using this focusing system, the laser microbeam instrument has got the focal spot size of less than 0.

用这个激光聚焦系统，激光微束仪能获得直径小于0。

the experimental method, measurement results and error analysis for testing the large scale non uniformity of 1 d and 2 d focal spot and interference speckles of the small scale have been presented.

报道了测定聚焦光斑一维、二维大尺度不均匀性及小尺度干涉斑纹的实验方法、结果及误差分析。

simulation results show that the size of the focal spot increases with the number of color cycles and the basic pulse bandwidth in the dispersing direction.

模拟结果表明，焦斑尺寸随色循环数和光栅色散方向上基準脉沖带宽的增加而增大。

it is well known through many finished physics experiments that the characteristic of focal spot is one of the most crucial factors which determine whether ignition can realize or not.

高功率激光束焦斑特性是影响聚变物理实验的关键因素之一。

the upper limit values of blurred area coverage of focal spot caused by the fluctuation of accelerating gap voltage are also calculated using a approximate method.

同时通过近似计算给出了由于加速间隙电压波动引起束聚焦焦斑模糊范围增大的上限值。