Carbonaceous chondrites meteorites contain abundant organic materials as they have not been melted, and much of their original chemicalcomposition remains intact.
碳粒陨星陨石包含大量的有机物，由于它们没被熔化，原来化学成分的大部分仍然完整无缺。
2
This paper depicts the chemicalcomposition, mechanical performance of X80 line pipes, giving emphasis to the welding materials and welding processes of fully automatic welding and manual welding.
文章叙述了X80管线钢的化学成分、力学性能，并重点介绍了采用全自动焊和手工焊的焊接材料及焊接工艺。
3
Chemicalcomposition, melting processes, casting and heat treatment of high chromium cast iron were determined according to the requirement of materials for dredge pump cover.