The main classesofmaterials are metals, polymers, ceramics, and composites.
材料的主要分类为金属、高聚物,陶瓷,及合成材料。
2
Arranging production manufacturing classes in construction materialsclasses violates the rules of classification, and making partial classes are not equalization.
建筑材料类编列生产制造类目违背分类法编制原则,且造成局部类目不均衡。
3
This paper discusses the status and trends of the films classes, the materials used in the PDP and the technology for the preparation of films.