<正> A detailed comparison was done between the data about the F in coals pub- lished at home and abroad,and associated with the special situation in China.An i
<正> The surface subsidence process associated with Iongwall mining operations is often capable of causing disturbances to various surface structures.Inadequate
<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