PWNabbr.脉宽调制（pulse width modification）Pn.字母Ppygidial gland臀腺pyritic action自热脱硫作用pyridine oxide氧化吡啶,氧化氮苯P. p. a.[医] 先摇瓶pyoblennorrhea[医] 脓液溢pyloric ostium幽门口P. purueumer矮象草Pyeloileostomy肾盂回肠吻合术pyknosis index固缩指数pyofluorescein绿脓菌荧光素