The porositygradient of porous aluminium is mostly affected not only by the spontaneous stacking density of granules, but also by the infiltration pressure gradient and solidification sequence.
多孔铝合金的孔隙率梯度主要是由渗流驱动压力梯度与凝固顺序所决定，而颗粒的自然堆积密度影响相对较小。
2
Igneous rock with strong magnetic susceptibility, leading to strong internal magnetic field gradient, and to T2 spectrum forward and NMR porosity decrease.