Viewed from inside the tube, this field looks like an accelerating electrical pulse, and it is this pulse that picks up and carries the electrons-or, if the polarity is reversed, the protons.
从腔内看，此电场就如同一个加速电流脉冲，该脉冲可选中并携带电子，或在极性逆转时选中并携带质子。
2
Electrical cables plugged in the wrong way would switch the "polarity" of a sensor, causing it to confuse left and right.
如果电缆放置错误将改变传感器的“极性(polarity)”，其后果是混淆了左和右。
3
Polarity effects and the influences of different electrical parameters on wheel dressing efficiency and accuracy were studied in the experiments.