Terahertz-frequency phonon-like modes in DNA have been widely studied both experimentally and theoretically in recent years. However, current theoretical models turn out to fail to reproduce some basic properties of these modes. Using a generalized hydrodynamics approach and the results of inelastic X-ray scattering measurements, we propose a model to describe structural effects due to wave number-dependence of the static structure factor in the dynamics of longitudinal acoustic-like excitations in DNA. Our analysis qualitatively suggests that on a length scale corresponding to a wave number region between the positions of the maximum and the minimum of the dispersion relation for the excitation frequency, structural effects may induce a tendency of delocalization of the dynamics. This proposal is consistent with the recent experimental observations of delocalized terahertz-frequency DNA phonon-like modes that seem to be relevant to biological function.

近年来，在实验和理论上都广泛研究了DNA中的太赫兹频率声子样模式。但是，当前的理论模型证明无法重现这些模式的一些基本属性。使用广义流体力学方法和非弹性X射线散射测量的结果，我们提出了一个模型来描述结构效应，该结构效应是由于DNA中纵向声学样激发的动力学中静态结构因子的波数依赖性所致。我们的分析定性地表明，在与激励频率的色散关系的最大值和最小值的位置之间的波数区域相对应的长度尺度上，结构效应可能会引起动力学离域化的趋势。