双作用单活塞杆液压缸
two-action single-rod hydraulic cylinder
双作用常接触弹性滚子旁承
double acting
constant contact
resilient roller side bearing
双作物系数法
dual crop coefficient method
dual crop coefficient approach
双柱塞超微量泵
double-plunger ultramicro pump
双重作用控制器
double response controller