frictionizev.擦frictionn.摩擦；摩擦力；分歧friction velocity cover冲刷friction test equipment摩擦试验装置friction sawing machine[机] 磨擦锯机frictional loss of head水头摩擦损失friction driving device摩擦传动装置Frictional oxides layer摩擦氧化层friction damping factor摩擦阻尼系数friction-board hammer夹板锤,圆盘摩擦锤friction-retained pin摩擦固位钉friction and resistance摩擦磨损