Darcy-Weisbach断面流速公式
Darcy-Weisbach formula of velocity profile
XNR-400熔体流速仪
XNR-400 melt flow index tester
氨气流速测量
Ammonia velocity measurement
被动流速容量技术
Passive expiratory flow volume technique
边界紊流速度
boundary turbulent velocity
便携式气流速度计
portable air velocity meter