Key strata is a rock seam which plays an important controlling roles in the movement of mining overlayer strata while the key strata is sometimes made up of two or more compound rock strata 摘要在采場覆巖運(yùn)動中起主要控制作用的巖層為關(guān)鍵層,而有時關(guān)鍵層是由2層或2層以上巖層形成的復(fù)合巖層所組成,我們稱其為復(fù)合關(guān)鍵層。
英文解釋
protective covering consisting, for example, of a layer of boards applied to the studs and joists of a building to strengthen it and serve as a foundation for a weatherproof exterior 同義詞:sheathing, overlay,
百科解釋
An overlayer is a layer of adatoms adsorbed onto a surface, for instance onto the surface of a single crystal.