7种煤煤质
coal quality of seven coal samples
煤变质分带
coal metamorphic zoning
Alternation zones of coal
煤质变化
coal quality variation
coal property change
the variety of coal grades
coal varitation
the coal quality variation
Change of Coal Quality
the Change of Coal Type
神华煤煤质基本特性
Basic Charateristics of Shenghua Coal
变质变形
metamorphism and deformation
metamorphism-deformation
变质变形期次
metamorphic-deformation episode
变质变形作用
Metamoiphism and deformation
变质变形作用特征
Deterioration distortion function characteristic