In silicate minerals and magnetites existed isomorph tin.

硅盐矿物和磁铁矿中都存在类质象态锡。

According to the concept of context process problem space,. the concept of Directed Assembly Relationship Graph(DARG) was put forward. The isomorph of DARG was defined.

根据上下文工艺问题间的概念,提出了有向装配关系的概念,定义了有向装配关系,以有向装配关系和零件通用属性来建实例库。