Researchers think it's the effect of convection currents in our planet's molten interior that causes the entire Earth to behave as one gigantic magnet, with a North and South Pole.
研究者们认为，是地球内部熔岩里对流流的作用使得整个地球像个拥有南北磁极的巨型磁体一样运转。
2
Bonded multi-polemagnet rotors are used in a wide variety of speed and commutation applications such as to rotary encoders, speedometers and machine controls.
多极磁铁转子广泛使用在各种速度和整流应用中，如对旋转编码器，里程表和机器的控制。
3
The self-holding ofa motor pole and the magnet rotor of the step motor can ensure the stable working situation, which reduces the energy consumption of the valve.