Zimmerman found that the pulsing field produced by the hands of practitioners is not steady in frequency, but varies from moment to moment.
齐默曼发现脉冲实地从业者手的频率并不稳定，但是从目前的时刻变化。
2
The frequency changing start up process of generating unit actually is a synchronous driving process under the action of electromagnetic moment of the stator and rotor of motor.
机组变频起动过程，实际上是电动机依靠定子和转子的电磁力矩作用的同步驱动过程。
3
The transfer of shearing and moment must be considered in dynamic analysis because the model of dowel bar affects the modal frequency and modal shape directly.