The studies of the soil properties suggested : (1) the bulk densities of the soils decreased and the generalporosity of soil increased after amelioration;
两个试验田改良后土壤性质定量研究表明：（1）土壤容重降低，土壤总孔隙度增加；
2
This paper describes the general characteristics of the variable porosity walls and the preliminary results of calibration at Mach Numbers ranging from 0.6 to 1.2.
本文介绍这种变开闭比斜孔壁的概况和马赫数0.6到1.2范围内的初步校测试验结果。
3
In general, smaller grain size and greater angularity tend to increase the porosity while an increase in range of particle size tends to decrease porosity.