This paper mainly focused on the gas emission law of coal wall for the double tunneling working faces.

简要论述了煤巷综掘工作面瓦斯涌出的特征及规律，提出了综掘工作面瓦斯涌出的控制与解决措施。

youdao

In this paper, the Periodic unsteady state heat conduction of coal wall in the front of underground coal gasification stove is researched.

研究了煤炭地下气化炉前方煤壁的周期性非稳态导热。

youdao

We have analysed the geological hydrology state of Lingquan open-pit coal mine, and proposed the coal extraction scheme of this mine F4 shear-zone coal wall.

分析了灵泉露天煤矿地质水文状况，提出了该矿f 4断层带煤壁回采方案。

youdao

The front page, as always, was filled with three- and four-line advertisements for Newcastle, Silkstone, or Wall's-End coal, Bailey's elastic stockings, ladies' abdominal belts, Pulvermacher's Patent Galvanic Chain Bands, Antakos corn plasters, Iceland Liniment for chilblains, and "Want Places" appeals from wet nurses, scullery maids, and cooks, each willing to supply testimonials about their skills and finer qualities.

NPR: Excerpt: 'Exiles'

Wall Street values the reserves of coal companies at 7 cents per million Btu of chemical energy.

FORBES: Magazine Article

The investigations into coal ash have been ongoing ever since a retention wall owned and controlled by the TVA broke in December 2008.

FORBES: Coal Ash Spilling Into Obama and Romney Race