When the distance between the axis of the inner conductor and the bottom of the trough tends to infinity, the results obtained in this paper go into that of the well-known slab line.

当此槽形线底部与中心圆柱的轴线间的距离趋于无限大时，我们即得到人的所熟知的两平板间具有中心内导体的传输线的结果。

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Peak falls on trough to create a core of darkness along the lens's central axis.

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