The electromagnetic force decays rapidly in the molten steel, and its decaying speed is related to the current frequency and polarpitch of the stirrer.
Normally planes don't go to the polar post from February to October because of the dangers of flying in the pitch-dark and cold.
通常情况下,飞机不会在2月到次年10月之间经行极地,因为在漆黑、寒冷的天气下飞行是很危险的。
3
The polar equation of non-circular gear pitch curve, calculation method of center distance, formula of pitch curve length, primary circle radius and pressure Angle is given.