The relations among great powers are the kernel of international relations and the main component and impulse of the setup of the world.
大国关系是国际关系的核心，是世界格局的主要构成和推动力量。
2
Whether there exists a periodic impulsecomponent in a vibration signal is an important sign of a mechanical device being faulty.
机械设备振动信号中是否存在周期性的冲击分量是其有无故障的重要标志。
3
However, in respect of a vibration acceleration signal, the signal to noise ratio (SNR) is often so small that the periodic impulsecomponent is submersed in its intense background noises.