principal act主要行为principaladj.主要的；首要的n.本金；资本；校长；主角；委托人；主犯principal axis of compliance柔性主轴principal line of photograph象主纵线principal stress orientation主应力方向角principal angle of incidence主入射角principal extensional stress主张应力principal aberration lateral主旁(向)像差, 主横像差principal curve segmentation分割主曲线principal composition series主组成列principal refractive indices舟射率principal state polarization主偏振态