The friction increases with the decrease in solid surface finish and tends to decrease with the increase in its surface hardness.
土壤摩擦力还随固体表面光洁度降低而增加，随表面硬度增加而趋于减小。
2
The effective friction coefficient is applied to the study of the oblique impact of a rigid sphere against a ductile solid.
此有效摩擦系数被应用于研究刚性球自由斜冲击延性靶问题。
3
The direct shear tests are more accurate in simulating friction behavior between blocks of solid waste feasible to determine the strength parameters of solid waste.