Rotating magnetic field is not caused by mechanical methods, but in AC pass in a few of the electromagnet, the nature of its magnetic cycle of change can be seen as rotating magnetic field.

转动磁场并不是用机械方法造成的，而是以交流电通于数对电磁铁中，使其磁极性质循环改变，可看作为转动磁场。

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Now that the Sun is approaching the peak of its magnetic cycle, when solar storms - blasts of electrically charged magnetic clouds - are most likely to occur, no one can predict how it will behave.

现在，太阳正在接近其磁周期的顶峰，也就是太阳风暴最可能发生的时期，没有人能够预测到太阳未来的表现。太阳活动会持续低迷？

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The magnetic activity of stars like sun, which is the root cause of the sunspot cycle, is still poorly understood even after decades of intense study.

磁场的变化是像太阳这样的恒星表面黑子活动周期的根源，尽管经过几十年的认真研究之后，地球人仍然对其知之甚少。

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Matt Penn and William Livingston of the National Solar Observatory predict that by the time Solar Cycle 25 arrives, magnetic fields on the sun will be so weak that few if any sunspots will be formed.

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