As the construction of ecological civilization has become more and more important in recent years, ecological restoration and its effect assessment have also received increasing attention. Taking the Wangping coal mine in Beijing as an example, based on Landsat TM/OLI series remote sensing data, we chose five metrics, i.e., fraction vegetation coverage, humidity, heat, dryness, and black particulates, to construct the model for the modified remote sensing ecological index (MRSEI). It was also combined with the Hurst index to conduct dynamic monitoring, spatiotemporal analysis, and prediction studies of the ecological environment quality in the study area. The results showed that: (1) Compared with the RSEI, the first principal component of the MRSEI better integrates the information of each component indicator, has a better average correlation with each indicator, and better reflects the habitat condition in the study area. (2) The mean value of the MRSEI in the study area increased from 0.433 in 1990 to 0.722 in 2021, an increase of 40.03%. (3) From 1990 to 2001, the poor and fair MRSEI-grade areas in the study area were concentrated in the northeastern and southwestern parts of the area. After the ecological restoration project was carried out, the environmental quality of the Wangping coal mine improved year by year, and a small number of poor areas were concentrated in the northeastern border area. (4) The MRSEI of the Wangping coal mine predicted that the future ecological environment of the study area would show a general trend of continuous improvement, but a certain percentage of the area in the northeast had a weak antisustainability trend. The results of the study could provide a reference for ecological restoration planning, sustainable development, and the management of mining areas.
为解决葫芦素煤矿21105 工作面临空宽煤柱冲击地压治理难题,提出了超高压水力割缝卸压防冲技术.采用理论分析研究了高压水射流对煤层的切割深度,以及煤柱切割后的应力转移规律,提出了基于卸荷减载、增加塑性屏障区的超高压水力割缝卸压防冲机制.通过FLAC3D 模拟了临空煤柱在不同割缝工艺条件下的煤岩体应力分布规律,获得了煤柱区域割缝工艺参数.在葫芦素煤矿21105 工作面进行了工业性应用,试验区域内微震事件、应力水平及钻屑量较相邻对比区域均得到明显降低.研究结果表明:采用超高压水力割缝技术切割煤层能有效改变煤岩体应力分布状态,使高应力区向深部煤岩体转移,增大采掘空间附近的塑性屏障区范围,有效防治煤矿冲击地压事故.
针对现有定位终端大多只具有精确定位、撤离报警、紧急求救等功能,而不能实现生命体征监测功能的问题,设计了一种基于UWB技术、具备健康监测功能的定位手表.该手表采用TOF定位算法实现矿井巷道精确定位,将井下人员精确定位数据和生命体征健康数据传输至服务器,实现对人员位置信息和健康数据的实时监测.健康定位手表的关键技术主要有:矿井巷道线型TOF定位算法,心率、血氧和体温等生命体征监测技术,三轴传感器检测运动状态及低功耗休眠机制.测试结果表明:该手表定位精度小于等于±0.30 m、定位距离可达 400 m,对心率、血氧和体温等生命体征的监测功能正常,平均工作电流小于2 mA,最小休眠电流小于500 μA,满足了定位终端智能化、多样化需求.
In order to construct the early warning system of mine belt fire and prevent the external fire accident of roadway, the pyrolysis process of belt at 5 K/min, 10 K/min, 15 K/min, 20 K/min heating rates was studied by thermogravimetric-Fourier infrared spectroscopy experiment combined with pyrolysis kinetics. The results show that the TG/DTG curves and gas products at different heating rates have similar laws and trends, and the eigenvalues of each parameter lag to the high temperature direction with the increase of heating rate. The pyrolysis of tape experiences two obvious weight loss stages. The first weight loss stage may occur cross-linked polycondensation pyrolysis reaction. The activation energy E ranges from 105 kJ/mol to 107 kJ/mol and the pre-exponential factor is 15.92 min -1 . The endothermic reaction of dechained pyrolysis and exothermic reaction of volatile oxidation may occur in the second weight loss stage. The activation energy E ranges from 130 kJ/mol to 220 kJ/mol and the pre-exponential factor is 37.13 min -1 , which is higher than that in the first weight loss stage. The two-stage pyrolysis process can be characterized by the Avrami-Erofeev equation.
为探索灰岩顶板条件下的瓦斯赋存状态及抽采方案,开展了灰岩的X射线衍射实验,研究了灰岩的物理化学特性,分析了灰岩对顶板瓦斯赋存和瓦斯抽采的影响.以山西沁源常信煤矿 90107工作面为工程背景,先用经验公式理论计算顶板"两带"高度,再结合 3DEC数值模拟软件分析回采过程中顶板破坏形态及裂隙发育特征,根据顶板裂隙发育优势区设计高位定向钻孔瓦斯抽采方案,最后通过现场实测验证.研究表明:随着工作面的推进,顶板初次垮落步距为40 m,周期垮落步距为40 m,垮落带高度为11.4 m,裂隙带发育高度为50 m,裂隙发育优势区为 11.4～25.0 m;现场实测发现上隅角和工作面瓦斯超限问题得到有效解决.抽采后,上隅角瓦斯浓度始终保持在0.8%以下,上隅角瓦斯浓度降幅最大可达87.5%.研究结果为相似灰岩地质条件下瓦斯高效抽采提供了参考依据.
