原子尺度上的波

提出全同粒子以及虚粒子假设,并推导了二维速度控制条件,再结合原子势函数,在原子尺度上描述了线性波的传播。考虑晶格非谐性以及位错的影响,进一步探究了二阶非线性波的产生机理。理论分析表明,晶格非谐性和位错引起的晶格畸变会诱发产生高阶虚粒子,高阶虚粒子是高阶非线性波产生的关键因素,位错等材料早期非线性或细微损伤导致高阶虚粒子增多而引发明显的高次谐波,因此,可以通过探测高次谐波诊断材料早期损伤。

Wave at the atomic scale

With proposing identical particle and virtual particle hypothesis, the control condition of two-dimensional velocity is derived,and the propagation of linear waves is described at the atomic scale with using interatomic potential functions.Furthermore, the generation mechanism of the second-order nonlinear waves is studied by considering the effects of lattice anharmonicity and dislocation. The study shows that the lattice distortion caused by lattice anharmonicity and dislocation induces high-order virtual particles, which are the key factor in generating the high-order nonlinear waves, and early-stage nonlinearities or micro-damages, e.g., dislocation, lead to the increase of the high-order virtual particles, which induces obvious high-order nonlinear waves. Therefore, the early-stage micro-damages can be identified by detecting the high-order nonlinear waves.