When the sun's rotation sweeps this warped surface across the earth, we detect sudden changes in the polarity of the magnetic field . 当太阳的自转使这个波浪形间隔面扫过地球时,我们就会探测到磁场极性的突然反转。
Two - pole plug for polarized secondary clocks ; connecting dimensions 固定极性的子钟用两极插头.连接尺寸
This will wash the strongly polar components from the column 这样就可以将强极性的成分从柱子中洗脱下来。