In this paper, the early hydration processes of cement pastes including various contents of coal stone were studied by alternating current impedance spectroscopy.

采用交流阻抗谱方法对掺加不同量煤矸石的水泥浆体的早期水化过程进行了研究。

youdao

He could sense the right place to hit so that the rock crust would cleave and reveal the coal, in the same way that a sculptor can sense exactly where to hammer a chisel into a stone.

他可以感觉到正确的敲击位置，这样岩石的外壳就会裂开显出煤矿，正如雕塑家可以精确知道在石头的什么位置而用凿子敲击一样。

youdao

Coal deposits, after all, are petrified peat swamps, and peat is made from decaying plants, which leave their imprints in mud and clay as it hardens into shale stone.

毕竟煤炭矿床本身就是石化的泥炭沼泽，而泥炭的成份是腐烂的植物。当粘土泥浆逐渐硬化成页岩石，腐烂的植物则在上面留下了它们的印记。

youdao

Mining has declined in importance in recent years with only coal and quarry stone mines remaining active.

FORBES: Swaziland

Freight included coal, corn, stone, iron, timber, rope and chalk and later building materials for the Great Western Railway.

BBC: Revived part of Wilts and Berks Canal officially opened

Stone, bronze, iron, gold, coal and oil are but a few of a long list of geological resources that have helped shape society.

UNESCO: UK National Commission for UNESCO :: Earth Sciences