机械减面率 slip ratio ; Mechanical reduction

定速轮减面率 Fix speed capstan slip ratio ; Fix speed capstan dia

面缩率、减面率 reduction of area

减面率梯度 taper draughting

断面缩减率 [材] reduction of area

面积减少率 Ratio of decreased area

面积削减率 Area reducing rate

耕地面积减少率 reduction rate of the cultivated area