He also realised that varying the strength of an electric field would generate a changing magnetic field, even in empty space with no moving electric charges to speak of.

他同时认识到，变化电场强度将会产生一个变化的磁场，甚至在一个没有移动电子的空间中也是如此。

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Although the description of the system involves the electromagnetic potential, the physical properties only depend on the electric and magnetic field-strength.

结果表明，虽然对体系的描述涉及到电磁势，但体系的物理性质只依赖于电场和磁场的强度；

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This paper introduces the method of calculation of strength of electric field excited at random point around the uniformly electric ring.

介绍了计算均匀带电圆环在周围空间任意点激发的电场强度的方法。

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