1、The Vickers hardness exhibits a linear increase and the relative density increases too.
復合材料的硬度呈直線增加，相對密度也增大。

2、having high relative density or specific gravity.
具有很高的相對密度或者比重。

3、The relative molecular weight is 852 by using viscometry, its relative density is 1.
采用黏度法測定膦基聚馬來酸的相對分子質量為852、相對密度為1。

4、having low relative density or specific gravity.
具有很小的相對密度或者比重。

relative density翻譯