Research on evolution of mining pressure field and fracture field and gas emission features

The relation between mining pressure field-fracture field and gas emission of working face is analyzed, and the concept that there is a stress point （or strain point） among permeability of coal is presented. It is believed that the mutation of coal permeability caused by the sudden loading or unloading of working face roof as periodic weighting occurs is the main reason that a lot of gas pour into the working face. Based on the above concept, the relation is established among abutment pressure during periodie weighting, permeability of coal seam and gas emission, and relation graph is drawn. Then the loading and unloading features of coal at the moment of fracture and non-fracture of main roof are revealed. And finally it is presented that the process of sudden loading or unloading as periodic weighting occurs plays an important role in rupture propagation of coal, analytical movement of gas and gas emission.

强化农业 惠及农村 富裕农民——代表聚焦“三农”话题

农业、农村、农民的"三农"问题关系到国民素质、经济发展,更关系到社会稳定、国家富强。在十二届全国人大一次会议上,来自吉林这个农业大省的众多代表,都不约而同地把目光焦聚在"三农"上。他们凝心聚智,建言献策,并纷纷表示,必须深入贯彻十八大精神,持之以恒强化农业、惠及农村、富裕农民,推动"三农"事业不断向前发展。