This is the basic principle behind electromagneticpropulsion.
这是电磁推进力的基本原理。
2
It is now known that since its inception, its primary purpose was research into electromagneticpropulsion.
现在已经知道,自成立以来,其主要目的是研究电磁推进。
3
The electric field, magnetic field and electromagnetic force have better penetrated ability but less near-wall strength whiles the propulsion units of wider magnetic poles.