phase-looked loop
相位同步回路，锁相环路

• Rayleigh-jeans law
• Rayleigh limit
• Rayleigh quarter-wave limit
• Rayleigh quarter-wave tolerance
• Rayleigh resolution limit
• Rayleigh-Ritz variational procedure
• Rayleigh scatter
• Rayleigh's law
• Rayleigh-Sommerfeld formulation
• Rayleigh spectrometer
• Rayleigh wave
• Rayleigh-wing scattering
• ray of light
• ray plot
• ray plotter
• raytracing device
• ray trajectory
• ray velocity
• R-branch
• R-branch emission
• reactance
• reactant
• reaction
• reaction force
• reaction principle