In practice there are three methods of accomplishing this phase difference. 在實(shí)踐中有三種方法來(lái)獲得相位差。
A frequency tracking method is proposed.The synchronism sampling is achieved to improve the measuring precision of frequency and phase difference. 本文提出一種頻率跟蹤方法，可以在不過(guò)零開(kāi)始采樣的情況下，實(shí)現整周期采樣，保證頻率和相位差測量的精度。
The phase difference between the two sources is gradually drifting with time. 兩個(gè)源的位相差隨時(shí)間逐漸移動(dòng)。
Compare with the results obtained from the experiment, isotherm and the rule of phase interface moving obtained from the simulation are almost the same. 和實(shí)驗結果相比，通過(guò)數值模擬得出的等溫線(xiàn)和界面移動(dòng)規律形狀都與實(shí)際情況相差不大。
