In recent years, urbanization in China has stepped into an acceleratingphase. Amidst magnificent achievements, there have emerged some complicated problems.
近年来，中国城市化进人加速阶段，取得了极大的成就，同时也出现了种种错综复杂的问题。
2
The analytical expressions for the phase and group velocities of the axial optical field, accelerating potential and energy gain etc. are derived and are used to make numerical analysis.
给出了轴上光场的相速度和群速度、加速电位及电子能量增益等的解析表达式，并作了数值计算和分析。
3
It is also found that the formation of reversed micelle in the organic phase could improve the extraction rate greatly and the extraction process exhibited obvious dynamic accelerating function.