瑞利分布的气象雷达回波，时频分析，功率谱密度，频谱分布。-Rayleigh distribution of meteorological radar echo time-frequency analysis, power spectral density, spectral distribution.

数值模拟方腔内Rayleigh-Benard对流。采用交错网格投影法，能量方程采用松耦合方法。-Numerical Simulation of square cavity Rayleigh-Benard convection. Using staggered grid projection method, the energy equation using loosely coupled approach.