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What is the reason for the magnetic force of the electromagnet?時(shí)間：2018-04-13The effect of physics on the magnetic size of the electromagnet: First, with the number of turn.. |
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Thousands of ways to become "special steel"時(shí)間：2018-04-1392-year-old Cui Kun, an academician of the Chinese Academy of Engineering, wore a shirt for 30 years.. |
