phase II第二阶段phasen.相位；方面；局面；阶段；时期vt.逐步执行phase shift coefficient相位常数phased array ultrasonic相控阵超声phase sensitive trigger相敏触发器phase-conjugate waves相位共轭波phase center correction改化Phasestructure function相位结构函数Phase-shift operators相移算子phase auto-adjustment相位自调整phase encoding gradient相位编码梯度phase-lock modulation锁相调制