<正> According to the cover rock caving features,the gob of fully mechanized caving face was divided into 3 zones: natural collected zone,pressure effecting zon
<正> The calculating methods for path number and path matrix of ventilation net- works without unidirectional circuits were introduced,and the inapplicability p
<正> Based on the systematical analysis influence factors of coal and gas outburst, the main factors and their magnitude was determined by the corresponding met
<正> Compared chemical bonds change situation of coal surface and oxygen mole- cules before and after coal surface adsorption to three oxygen molecules,after ad