system 1
长距离红外系统 system 2
(1)制(度)
(2)系统，体系
(3)装置
(4)晶系

• partial polarized light
• partial pressure
• partial reflectance
• particle
• particle beam weapon
• particle concentration
• particle diameter
• particle path
• particle shape
• particle size
• particle sizing
• particular solution
• partition
• pascal
• Paschen-Back effect
• Paschen bands
• Paschen mounting
• Paschen notation
• Paschen serier
• passage
• passage zero
• passameter
• passatest
• passband
• passband ripple