Experts say the denser the material, the less radiation reaches the skin.

VOA: special.2010.07.06

So, aluminum is about 50% denser than magnesium.

所以铝的密度比镁大一倍。

麻省理工公开课 - 固态化学导论课程节选

The classical hoplite formation then was not the long lived military institution of scholarly tradition, but merely one phase in a history of almost four centuries of slow change towards ever denser and more cohesive heavy infantry formations."

这种方阵的形成,并不是经过长期传承的传统军事制度,只是步兵阵型演变的一个阶段,战阵逐渐向更加紧密坚固的步兵阵型转化,而这个变化持续了约有四个世纪"

耶鲁公开课 - 古希腊历史简介课程节选