由于内核的存在，将出现两个新的与地球自转有关的章动模式，即顺向的自由核章动(PFCN)和内核摆动(ICW)模式。

Because of the inner core of the earth, there will have two nutation modes related to the earth's rotation, i. e. a prograde free core nutation (PFCN) mode and a inner core wobble (ICW) mode.

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根据地球自由核章动在周日重力潮汐观测中的共振效应确定了自由核章动的复本征周期和品质因子Q 值，研究了极移重力效应；

The complex eigen period period and Q value of the FCN are evaluated based on the resonance observed in the diurnal tidal gravity, the gravity change due to the polar motion is also studied.

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