PM

= Passivated Mesa,钝化台面式晶体管;

= Performance Management, 性能管理;

= Permanent Magnet, 永(久)磁铁;

= Permanent Memory, 永久性存储器;

= phase modulation, 调相制，相位调制;

= Photoelectric Multiplier, 光电信增器，光电信增管