( 4 ) the correlation property between the distribution of attenuation factor and that of the group velocity is indicated , in this study ( 4 )研究结果显示，在频率域内，面波衰减系数分布与群速度分布具有一定的相关性。
The group velocity ( u ) corresponds to the net result from the addition of all elements with different periods and different velocities within the wave motion 而群速度（ u ）符合于波动的不同周期，不同速度的各种因素叠加的净结果。
The study based on self phase modulation mechanism and the effects of gvd on sc generation are mostly focused on by analyzing and calculating theoretically 本文主要研究群速度色散对光纤中自相位调制效应sc谱展宽的影响，分析了产生sc谱的物理机制。
For ultrashort few - cycle pulses , the group velocity dispersion should be considered , whose influence depends on the parameters of the beam and the material 对于几个光周期的超短脉冲，除透镜色差外，还应当考虑群速度色散，且其影响依赖于透镜材料和光束参数。
After doing the modifying of machine in calculating the real amplitude and frequency - time analysis to all selected records , the group velocity was calculated for each seismograms 对这些地震记录做仪器频响特性校正，同时进行频时分析( ftan ) ，求其群速度频散。
In general , the lens chromatic aberration and the group velocity dispersion lead to a broadening in the temporal and spatial intensity distributions at the focal plane and a decrease o 一般说来，透镜色差和群速度色散会使焦平面上脉冲光束的时间、空间光强分布展宽，峰值光强降低。
In chapter 3 , spatiotemporal instability of ultrashort pulses results from the interplay among diffraction , group - velocity dispersins and nonlinearity . we use the model proposed by brebec et al . , 第三章：超短脉冲的时空不稳定性是衍射、群速度色散和自相位调制三者之间的相互作用导致的。
Secondly , wavelet transform is applied to compute the arrival time of the lamb wave group velocity experiments results demonstrate that wavelet transform can improve the precision of damage localization 其次，本文采用小波分析方法提取lamb波群速度的到达时间，获得了比阈值法及互相关方法更高的精度。
( 2 ) calculating the gridded rayleigh wave attenuation factor y and group velocity . the lsqr algorithm is used to inverse the attenuation factor and group velocity under 4 ? x4 ? gridding and 2 ( 2 )进行rayleigh波衰减系数、群速度网格化纯路径衰减反演计算，得到网格单元纯路径衰减系数和群速度分布结构。
Under certain conditions , in spite of their different modal indices the two polarized components of the pulse can trap one anther and move at a common group velocity due to xpm , the phenomenon referred as self - trapping occur 在一定条件下，尽管脉冲的两个偏振分量的模式折射率不同，但由于交叉相位调制效应，它们能相互俘获并以共同的群速度传输，产生自捕获现象。
