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排序方式: 共有783条查询结果,搜索用时 265 毫秒
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针对云南富源县辖区内大量小型煤矿抽采的低浓度瓦斯未开展有效利用的问题,以区内某小型煤矿为背景,采用现场调研、分析归纳、理论计算相结合的方法对其低浓度瓦斯发电项目展开分析研究。研究表明,某小型煤矿低浓度瓦斯发电项目成功的关键是“瓦斯治理先行”理念主导下的气源保障综合技术体系。在气源得以保障的基础上,该小型煤矿低浓度瓦斯发电项目已经持续高效运行4年,每年创造经济收益约403.2万元,减排CO2约4.47万t;同时促进了煤矿瓦斯治理工作有效落实,提高了煤矿安全生产水平,保障了煤矿产量的达标。 相似文献
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《Journal of the European Ceramic Society》2005,25(9):1629-1636
Ultimate tensile strength of five different continuous fiber-reinforced ceramic matrix composites (CMCs), including SiCf/BSAS (two dimensional (2D), 2 types), SiCf/MAS (2D), SiCf/SiC (2D), and Cf/SiC (2D, 2 types), was determined as a function of test rate at 1100–1200 °C in air. All five CMCs exhibited a significant dependency of ultimate tensile strength on test rate such that the ultimate tensile strength decreased with decreasing test rate. The dependency of ultimate tensile strength on test rate, the applicability of preload technique, and the predictability of life from one loading configuration (constant stress-rate loading) to another (constant stress loading) all suggested that the overall, phenomenological delayed failure of the CMCs would be governed by a power-law type of slow crack growth. 相似文献
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1 Introduction Natural rock mass is not homogeneous, and it is full of various weak planes with different structures and different geological mechanisms, such as fractures, joints, and cracks. These structural weak planes seriously hinder and affect the … 相似文献
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《矿业科学技术学报(英文版)》2017,27(4):681-685
Gas extraction practice has been proven for the clear majority of coal mines in China to be unfavorable using drill holes in the coal seam. Rather, mining-induced fractures in the goaf should be utilized for gas extraction. To study gas migration in mining-induced fractures, one mining face of 10 th Mine in Pingdingshan Coalmine Group in Henan, China, has been selected as the case study for this work. By establishing the mathematical model of gas migration under the influence of coal seam mining, discrete element software UDEC and Multiphysics software COMSOL are employed to model gas migration in mining-induced fractures above the goaf. The results show that as the working face advances, the goaf overburden gradually forms a mining-induced fracture network in the shape of a trapezoid, the size of which increases with the distance of coal face advance. Compared with gas migration in the overburden matrix, the gas flow in the fracture network due to mining is far greater. The largest mining-induced fracture is located at the upper end of the trapezoidal zone, which results in the largest gas flux in the network. When drilling for gas extraction in a mining-induced fracture field, the gas concentration is reduced in the whole region during the process of gas drainage, and the rate of gas concentration drops faster in the fractured zone. It is shown that with gas drainage, the gas flow velocity in the mininginduced fracture network is faster. 相似文献
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《材料科学技术学报》2019,35(10):2297-2304
Structure searches based on a combination of first-principles calculations and a particle swarm optimization technique unravel two new stable high-pressure structures (C2/m and Cmce) for TaN2. The structural features, mechanical properties, formation enthalpies, electronic structure, and phase diagram of TaN2 are fully investigated. Being mechanically and dynamically stable, the two phases could be made metastable experimentally at ambient conditions. 相似文献
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矿用直流不间断电源的设计 总被引:1,自引:0,他引:1
设计了一种煤矿井下交换机用直流不间断电源。该不间断电源采用MAX713电源管理芯片对镍镉电池进行智能充电;采用MSP430F147单片机作为微处理器,利用外部中断方式监测矿用交流电的工作状态,当发现矿用交流电不能正常供电时对电路进行切换,启动镍镉电池供电,从而保证交换机持续工作。测试结果表明,该不间断电源具有一定的实用性。 相似文献
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基于WCDMA的矿用M2M终端系统的设计 总被引:1,自引:1,他引:0
为了将井下人员信息、设备信息以及环境信息通过井下现有的通信网络传送至煤矿信息中心,提出了一种基于WCDMA的矿用M2M终端系统的设计方案,详细介绍了该系统硬件和软件的设计。该系统实现了对井下目标信息的采集、人机交互操作及数据通信功能,通过WCDMA网络将采集的数据互传,实现了物与物相联、物与人相联以及物与网络相联的物联网。 相似文献