Crystal oscillators are loosely divided with the frequency they perform at and whether or not they are fundamental oscillators—perform within the frequency marked around the can or at even multiples of that (overtone oscillators). Modeling of nonlinear micromechanical resonators and their simulation While using the harmonic‐equilibrium strategy 中原子或分子的排列具有三维空间的周期性，... https://www.hxcrystals.com/seokeywords/bulk-crystal-oscillator.html