暗煤

根据岩相的不同，把大同煤分为亮煤（C）和暗煤（D），以了解床温、停留时间和振动强度对碎裂特性的影响。

The Datong Bituminous coal was divided into clarain coal ( C ) and dull coal ( D ) according to their lithotypes to understand its fragmentation under different bed temperature , resident time , and vibrating frequency and amplitude .

丝炭和暗煤的顺磁共振特性研究

Study of ESR characteristics of fusain and Durain

分析可知延安组煤层以暗煤为主，亮煤次之。

By analyzing we can know that the Yanan Formation is mainly durain , with bright coal taking the second place .

三2煤皮带暗斜井揭煤支护技术研究

3_2 Seam Leather Belt Inside Slope Uncovers Coal to Support and Protect Engineering Research

含铀、锗煤主要为煤化程度低的褐煤，属于半暗-半亮、暗-亮煤及亮-暗煤。

Uranium , germanium-bearing coals are mainly lignites of low grade incoalation and belong to semidurain , semiclarain .