The objective of this dissertation is to study ancient bullas as Seal Cutting Art on characters transformation, prettification, combination and the arrangement .
本文的出发点是以篆刻艺术的眼光看待古玺中的文字的变形、美饰手段、组合方式和文字的排列方式（章法）。
2
The improvement seal was composed of combination of stuffing seal and labyrinth seal and protective gas was used.
对填料密封设计进行改进，采用填料与迷宫组合密封结构，加气体保护密封方案。
3
One and a half stages of a subsonic compressor were simulated with steady and unsteady calculation, comparing the performance with different combination of tip leakage and seal cavity.