According to the openness of process planning knowledge base, this paper proposes a hierarchy knowledge base model based on open structure.

The filter shell adopts quick open structure, can rapidly open upper cover and replace filter cartridge without using any tools.

Topological resonance energy (TRE) and bond resonance energy (BRE) methods were applied to all the open structure isomers (both cations and anions) of C36CH2 to investigate their aromaticity.