In silicate minerals and magnetites existed isomorph tin.

硅酸盐矿物和磁铁矿中都存在类质同象态锡。

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.

下文工艺问题间的概念,提出有装配关系图的概念,定义有装配关系图同构,以有装配关系图和零件通用属性来构建实例库。