We propose rheological models of micro- and structurally inhomogeneous media, which explain an increase in their acoustic nonlinearity with increasing wave frequency. The equations of state for such media are obtained and the frequency dependences of the nonlinearity parameters for the processes of generation of the second harmonic and the difference frequency are determined for the media with quadratic elastic nonlinearity.

中文翻译：

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具有频率相关非线性的微观和结构非均匀介质的流变模型和状态方程

我们提出了微观和结构不均匀介质的流变模型，这解释了它们的声学非线性随着波频率的增加而增加。获得了这种介质的状态方程，并确定了二次谐波产生过程的非线性参数和差频的非​​线性参数的频率相关性。