Stepan斯捷潘stepn.步骤；台阶；舞步；步伐v.踏；以步测量step response model阶跃响应模型step velocity input阶跃速度输入stepping motor bank步进马达群step polymerization阶段聚合step-bystep motor步进电机step by step switch步进开关step up the voltage使电升压step-changed LPGs阶跃长周期光栅级联Step-up structure进级结构Stepanka Hilgertova