<正>建立车辆与路基路面的动力学耦合仿真系统，对路基路面有限元动力学模型采用模态截阶方法进行降阶处理，并计算路面变形与轮胎作用力间的传递函数。在Simulink系统中对车辆与路基路面的动力耦合模型进行仿真，分析不同车速下的动态轮胎力与路面变形、路基刚度的关系及路基内部动应力的变化。

Using plantlet shoot sections near the shoot tip as initial explants, we observed the effects of several factors on induction buds, such as pre-culture time, 6-BA, TDZ, Cef, Km. From shoot sections we established a receptor system for genetic transformation. The results indicated that for shoot sections induction buds the optimal medium was DCR+6-BA (1.0mg/L)+TDZ (0.001mg/L)+NAA (0.1mg/L). Pre-cultured for two days, the bud induction frequency, average number of bud and bud forming capacity all reached the maximum, which was 100%, 6.35 and 6.35, respectively. Histological observations indicated that buds originate from the surface of the shoot sections, where Agrobaterium tumefaciens can reach. It was shown that sticking A. tumefaciens cells and developing buds cells share the same position.