Abstract: The present invention relates to a mining hose connecting device and method, and belongs to the field of underground hydraulic equipment for coal mines. The mining hose connecting device comprises a joint unit, wherein the joint unit comprises a first joint and a second joint; a first fastening unit, wherein the first fastening unit is arranged symmetrically about a first plane, and the inner diameter of the first fastening unit is respectively in clearance fit with the outer diameters of the first joint and the second joint; and a second fastening unit, comprising a first fastener and a second fastener, wherein the inner diameters of the first fastener and the second fastener are respectively in clearance fit with the outer diameter of the first fastening unit.

Abstract: A method of analyzing influencing factors of a contribution rate of elastic energy of a top plate during catastrophe of a coal body; the specific steps are: taking a core on site and processing the core into a standard test piece; obtaining, by means of an indoor mechanical test, elastic moduli of the top plate and of gas-containing coal, respectively; substituting the obtained elastic moduli and thicknesses of the top plate and of the gas-containing coal into a calculation formula so as to obtain the contribution rate of the elastic energy of the top plate; and analyzing the influence of the contribution rate of the elastic energy of the top plate in the two situations of configuring the same thickness ratio and a different elastic modulus ratio and the same elastic modulus ratio and a different thickness ratio. The method has important theoretical significance and practical engineering value.

Abstract: A method of analyzing influencing factors of a contribution rate of elastic energy of a top plate during catastrophe of a coal body; the specific steps are: obtaining coal seam gas pressure; according to a drilling histogram, obtaining coal seam thickness and top plate thickness; taking a core on site and processing the core into a standard test piece; obtaining, by means of an indoor mechanical test, elastic moduli of the top plate and of gas-containing coal, respectively; substituting the obtained elastic moduli and thicknesses of the top plate and of the gas-containing coal into a calculation formula so as to obtain the contribution rate of the elastic energy of the top plate; and analyzing the influence of the contribution rate of the elastic energy of the top plate in the two situations of configuring the same thickness ratio and a different elastic modulus ratio and the same elastic modulus ratio and a different thickness ratio.

Abstract: The present disclosure relates to a synthesis method of ?-nicotinamide mononucleotide (?-NMN) and an intermediate thereof. In the present disclosure, phospholipid metabolism enzymes phospholipase D (PLD) and phospholipase C (PLC) widely present in the biosphere are used as catalysts to prepare ?-NMN through two-step enzymolysis or one-pot synthesis; and an intermediate, namely phosphatidyl nicotinamide riboside (PNR), is obtained during the two-step enzymolysis. The present disclosure has simple reaction steps, low production cost, and environmental friendliness, and is suitable for large-scale industrial production.