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In order to solve the problems such as small influence range, fast decay rate, difficulty in gas disaster control and long treatment period of gas extraction drilling in Hebi Mining Area, a technological process of coordinated stamping operation was put forward, and the technical mode of drilling and stamping coordinated operation with automatic drilling rig group drilling - temporary sealing hole pre-pumping - stamping joint operation after pre-pumping is formed, and industrial test is carried out in Hebi No.6 Coal Mine for industrial trials, the field application results show that: the technology mode gives full play to the advantages of automatic drilling rig continuous drilling, fast operation, reducing staff and improving efficiency, realizes the specialization, continuity and scale of gas extraction drilling construction operation and hydraulic stamping coordinated penetration operation, and makes the construction work efficiency of construction of penetration drilling in the bottom rock tunnel for gas treatment increase by 48% under the same geological conditions; meanwhile, the at the same time, after the construction of extraction holes by automatic drilling rig is completed, the temporary sealing of the extraction holes is carried out, so that the free gas in the holes is greatly reduced after extraction, which greatly reduces the frequency of gas overrunning accidents in the roadway during the construction of hydraulic measures and effectively guarantees the safety of construction; the average gas extraction concentration of the test borehole is 1.31 times of that of the conventional hydraulic ramming measure, and the average daily pure extraction volume of the test unit borehole is 1.79 times of that of the conventional hydraulic ramming measure.

Low-temperature preservation is an important storage method for grass carp. Although low temperature can not completely inhibit the activity of enzymes in fish, it can significantly decrease the activity of enzymes and inhibit the growth and reproduction of microorganisms in fish, thereby prolonging the shelf life of fish. When the storage temperature is relatively low, the quality and taste of grass carp are not easily lost, thereby delaying its spoilage. In response to the national development plan of the cold chain circulation in the "14th Five-Year Plan", it is necessary to delay the shelf life of grass carp and reduce the quality change of grass carp through effective preservation technology. This paper summarizes the effects of low-temperature preservation of grass carp on microbial and enzyme activities and reviews the principles and methods of several common low-temperature preservation methods of grass carp (cooling preservation, ice temperature preservation, micro-freezing preservation, frozen preservation, modified low-temperature preservation, compound preservation and new preservation technology), and their application in grass carp preservation, preservation effect. This study aims to provide a reference for low-temperature grass carp preservation and find a more practical and economical way of grass carp preservation.