Crystal oscillators are loosely divided with the frequency they get the job done at and whether they are essential oscillators—perform at the frequency marked about the can or at even multiples of that (overtone oscillators). Modeling of nonlinear micromechanical resonators as well as their simulation with the harmonic‐stability system 中原子或分子的排列具有三维空间的周期性，隔一定的... https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html