The double-concave shape of REE patterns of the alkali basalt show that the basalt melt had reached equilibrium or quasi-equilibrium with the garnet and clinopyroxene megacrysts.
碱性玄武岩的双凹型REE配分模式是熔体与单斜辉石、石榴石达到化学平衡或近于化学平衡的结果；
Just as a double convex lens enlarges so a double concave lens reduces.
正象双凸透镜可以放大那样，双凹透镜也可以缩小。
The base has special concave design, and can be fixed with double-sided tape.
底板有特殊凹位设计，可以直接用双面胶固定。
应用推荐