The concave bottom mill shoe is used to grind downhole small objects and other unstable fallen objects.

凹底磨鞋可用于磨削井下小件落物以及其它不稳定落物。

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On seismic profile cross-cut the channel, it generally presents as a lenticle with flat top and concave bottom and has the character of infilling in reflection.

河道砂岩体在横切河道的地震剖面上一般表现为充填反射状的顶平底凹的单透镜体；

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An adhesive dike slot (31) is formed around the joint concave bottom, thus preventing the main body and the neck back side from dirtiness caused by excessive adhesive overflow.

粘合剂堤槽(31)形成在接合凹底部的周边，以防止用粘合剂连接时过量粘合剂溢出弄脏主体及琴颈的背面。

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Mr Giles's solution to the drag problem is a sharp bow that cuts through waves up to 40 feet high, and a concave hull bottom.

ECONOMIST: Fast container ships