Therefore it is possible to simply regard the value of the induction on unit length in the near middle of two "infinite length" parallel conductor as its approximate value.

故可简单的计算中部附近单位长度上自感作为“无限长”平行导体回路单位长度自感的近似值。

youdao

So we have started off with the conductor on the bottom, an insulator, a conductor in the middle.

所以我们一开始就是底部一层导体，一层绝缘体，中间再一层导体。

youdao

Don Melrose, also at Sydney, points out that the gas in the middle of the galaxy might already be so strongly ionised, and thus such a good electrical conductor, that current would leak away rather than build up into a concentration like the Snake.

ECONOMIST: Here be serpents