智慧城市建设在我国遍地开花,信息通信技术在智慧城市建设中发挥至关重要的作用。NB-IoT(Narrow Band-Internet of Thing,窄带物联网)是一种大容量、广覆盖、低功耗、高稳定性的广域物联网技术。首先,对表计行业通信现状以及NB-IoT的技...智慧城市建设在我国遍地开花,信息通信技术在智慧城市建设中发挥至关重要的作用。NB-IoT(Narrow Band-Internet of Thing,窄带物联网)是一种大容量、广覆盖、低功耗、高稳定性的广域物联网技术。首先,对表计行业通信现状以及NB-IoT的技术原理和特点进行介绍;并结合表计行业的应用实际以及NB-IoT的优势的分析,提出了基于NB-IoT技术的智能表计行业的解决方案。展开更多
According to the problem during mining coal seam with high gas and its control, the theory numerical calculation of gas and strata movement law caused by protection layer mining was studied, with the background of Sna...According to the problem during mining coal seam with high gas and its control, the theory numerical calculation of gas and strata movement law caused by protection layer mining was studied, with the background of Snake Mountain coal mine. First of all, the basic principle of fluid(gas)-solid coupling was briefly described, and a three dimensional model was established by FLAC software. Secondly, the calculation parameters of fluid-solid coupling were obtained based on the measured data, and the numerical calculation of sublevel mining was carried out in turn. Lastly, initial stress state, gas movement law, deformation law of pore pressure and movement characteristics of rock strata were studied, respectively. The results show that the gas and pressure were greatly reduced with the advance of 4 coal seam working surface, as well as the constant increase of area of goaf. Facilitating gas and the stress were gradually penetrated and released to goaf during the whole process of mining. The gas pressure, the aggregation degree and the surrounding rock pressure of the 1 coal seam and the 3 coal seam were greatly reduced.展开更多
文摘智慧城市建设在我国遍地开花,信息通信技术在智慧城市建设中发挥至关重要的作用。NB-IoT(Narrow Band-Internet of Thing,窄带物联网)是一种大容量、广覆盖、低功耗、高稳定性的广域物联网技术。首先,对表计行业通信现状以及NB-IoT的技术原理和特点进行介绍;并结合表计行业的应用实际以及NB-IoT的优势的分析,提出了基于NB-IoT技术的智能表计行业的解决方案。
基金Funded by the Open Research Foundation of Key Laboratory of Safety and High-efficiency Coal Mining,Ministry of Education(Anhui University of Science and Technology)(No.JYBSYS2015201)the National Natural Science Foundation of China(No.51574122)the Natural Science Foundation of Hunan Province,China(No.2017JJ2082)
文摘According to the problem during mining coal seam with high gas and its control, the theory numerical calculation of gas and strata movement law caused by protection layer mining was studied, with the background of Snake Mountain coal mine. First of all, the basic principle of fluid(gas)-solid coupling was briefly described, and a three dimensional model was established by FLAC software. Secondly, the calculation parameters of fluid-solid coupling were obtained based on the measured data, and the numerical calculation of sublevel mining was carried out in turn. Lastly, initial stress state, gas movement law, deformation law of pore pressure and movement characteristics of rock strata were studied, respectively. The results show that the gas and pressure were greatly reduced with the advance of 4 coal seam working surface, as well as the constant increase of area of goaf. Facilitating gas and the stress were gradually penetrated and released to goaf during the whole process of mining. The gas pressure, the aggregation degree and the surrounding rock pressure of the 1 coal seam and the 3 coal seam were greatly reduced.
