多面体

In this paper the relationship between the crystal forms and the growth mechanism of quartz and tinstone under the hydrothermal solution conditions has been studied.

本文研究了热液条件下，水晶和锡石的晶形态和生长机制的关系，提出了水晶和锡石的生长基元负离多面。

For a small cover over a polytope, its equivariant cobordism class is determined by the tangential representation set.

摘要多面上的小覆盖的等变边类是由它的切表示集所决定的。