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 point of objective物镜帚principal parts of recycling回收主体principal moments of inertia主惯性矩principal lateral aberration主横象差Principal - agent Analysis委托-代理分析principal place of residence主要住址; 主要居所principal resonant frequence主共振荡频率, 主鸣频(率)Principal Development Agency主要研制机构principal compressive stress主压应力principal component analysis种量分析,主成份分析