The periodic mean superposition method can predict the result through decomposing the hydrological time series into several periodic waves, extrapolating the periodic waves, and linear superposition.
周期均值叠加法将随时间变化的水文要素序列分离成若干个周期波，然后将周期波进行外延，再进行线性叠加，从而获得预报结果。
The interaction properties of periodic waves are found to be inelastic.
研究了这些周期波之间的相互作用，发现其相互作用是非弹性的。
Conditions for the existence of solutions to periodic and isolated waves of limited amplitude are directly obtained based on qualitative geometric theory for ordinary differential equations.
利用微分方程解的几何定性理论，直接得到该方程存在有限振幅的周期波与孤立波解的存在条件。
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