他们关注的不是星辰偕日升降，也不是地平线附近的星辰，而是永不落下的北极星和拱极星。
They concentrated attention, not on heliacal risings and Settings, not on the horizon, but on the pole star and on the circumpolar stars which never rise and never set.
以很多小段赫芝偶极之完整电磁场合成一任意线电流之近场与远场电磁场。
The near and far electromagnetic field are synthesized by summation of the electromagnetic field of short current segments or Hertz dipoles.
许多矩阵切换系统采用了三极保护继电器和配线。
Many matrix switching systems use three-pole guarded relays and wiring.
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