Initially, the material only made appearances in random household items like shower curtains, insulated wire and and rain coats.

最初，这种材料只出现在普通家居用品中，比如窗帘、绝缘电线和雨衣。

That means the magnetic field inside an ideal solenoid equals the magnetic permeability of free space times the turn density of the solenoid times the current through the insulated wire of the solenoid.

这意味着理想螺线管内部的磁场等于自由空间的磁导率乘以螺线管的匝密度乘以通过螺线管绝缘线的电流。