To meet the requirements of miniaturization, high gain and wideband of UHF antenna for aircraft SAR, the gain loss produced by narrowing back cavity of short back radiation antenna is analyzed.

针对超高频机载合成孔径雷达天线小型化、高增益和宽频带的问题，分析了短背射天线缩小背腔的增益损失。

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Back-scattered field of electrically large concave cavity is analyzed with CRmethod.

利用复射线法分析了电大尺寸凹腔的后向散射场。

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At the same time with the screw pump, screw and screw with each other form a sealed cavity between one another to ensure airtight, otherwise there may be liquid from the gap in the back to go back.

同时螺杆与泵体、螺杆与螺杆间又相互形成密封腔，保证密闭，否则就可能有液体从间隙中倒流回去。

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Each is lined with tissue called the mucosa, which secretes mucus continuously along hairy cells called cilia and out a tiny passageway called an ostium, through which the mucus drains into the nasal cavity and down the back of the throat, where it is swallowed (unless you blow your nose).

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