英语语法分析

Polymethylene polyphenyl polyamine is an intermediate product of polymethylene polyphenyl polyisocyanate (MDI).

多亚甲基多苯基多胺是多苯基甲烷多异氰酸脂(MDI)的中间体。

In this paper, fourth moment of end-to-end distance of polymethylene chains in the third-order interaction approximation is calculated.

计算聚亚甲基链的末端距四次矩，并同二级相互作用的结果进行了比较。