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排序方式: 共有3464条查询结果,搜索用时 31 毫秒
31.
《矿业科学技术学报(英文版)》2017,27(6):1073-1079
In order to obtain accurate probability integration method(PIM) parameters for surface movement of multi-panel mining, a genetic algorithm(GA) was used to optimize the parameters. As the measured surface movement is affected by more than one mining panel, traditional PIM parameter inversion model is difficult to ensure the reliability of the results due to the complexity of rock movement. With crossover,mutation and selection operators, GA can perform a global optimization search and has high computation efficiency. Compared with the pattern search algorithm, the fitness function can avoid falling into local minima traps. GA reduces the risk of local minima traps which improves the accuracy and reliability with the mutation mechanism. Application at Xuehu colliery shows that GA can be used to inverse the PIM parameters for multi-panel surface movement observation, and reliable results can be obtained. The research provides a new way for back-analysis of PIM parameters for mining subsidence under complex conditions. 相似文献
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《矿业科学技术学报(英文版)》2016,26(2):295-299
In order to study the evolution laws during the development process of the coal face overburden rock mining-induced fissure,we studied the process of evolution of overburden rock mining-induced fissures and dynamically quantitatively described its fractal laws,based on the high-precision microseismic monitoring method and the nonlinear Fractal Geometry Theory.The results show that:the overburden rock mining-induced fissure fractal dimension experiences two periodic change processes with the coal face advance,namely a Small→ Big→ Small process,which tends to be stable;the functional relationship between the extraction step distance and the overburden rock mining-induced fissure fractal dimension is a cubic curve.The results suggest that the fractal dimension reflects the evolution characteristics of the overburden rock mining-induced fissure,which can be used as an evaluation index of the stability of the overburden rock strata,and it provides theoretical guidance for stability analysis of the overburden rock strata,goaf roof control and the support movements in the mining face. 相似文献
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《矿业科学技术学报(英文版)》2016,26(6):1117-1123
In order to study the influence of depth-thickness ratio on bedding slope stability, whose sliding surface is flexural concave in shape under mining conditions, this paper aims to study the characteristics of deformation and damage of bedding sliding with depth-thickness ratios of 200:1, 150:1, 120:1, 100:1 and 50:1by adopting numerical simulation analysis software combined with laboratory-made ‘‘under the influence of mining variable sliding surface slope similar simulation test bed", and to propose identification methods for slope stability under the influence of mining. The results show that mining activities under the slope reduce slope stability. With a decrease in the mining depth ratio, the influence of mining on the slope increases gradually, and the damage to the slope gradually expands, the stability of the slope gradually reduces, fracture occurs on the slope toe and the central fissure gradually develops to the surface,and reaches slide threshold when the depth-thickness ratio is 50:1. 相似文献
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《矿业科学技术学报(英文版)》2016,26(6):1065-1071
Near-surface deposits that extend to considerable depths are often amenable to both open pit mining and/or underground mining. This paper investigates the strategy of mining options for an orebody using a Mixed Integer Linear Programming(MILP) optimization framework. The MILP formulation maximizes the Net Present Value(NPV) of the reserve when extracted with(i) open pit mining,(ii) underground mining, and(iii) concurrent open pit and underground mining. Comparatively, implementing open pit mining generates a higher NPV than underground mining. However considering the investment required for these mining options, underground mining generates a better return on investment than open pit mining. Also, in the concurrent open pit and underground mining scenario, the optimizer prefers extracting blocks using open pit mining. Although the underground mine could access ore sooner, the mining cost differential for open pit mining is more than compensated for by the discounting benefits associated with earlier underground mining. 相似文献
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《矿业科学技术学报(英文版)》2016,26(5):745-752
Data collected from truck payload management systems at various surface mines shows that the payload variance is significant and must be considered in analysing the mine productivity,energy consumption,greenhouse gas emissions and associated cost.Payload variance causes significant differences in gross vehicle weights.Heavily loaded trucks travel slower up ramps than lightly loaded trucks.Faster trucks are slowed by the presence of slower trucks,resulting in‘bunching’,production losses and increasing fuel consumptions.This paper simulates the truck bunching phenomena in large surface mines to improve truck and shovel systems’efficiency and minimise fuel consumption.The study concentrated on completing a practical simulation model based on a discrete event method which is most commonly used in this field of research in other industries.The simulation model has been validated by a dataset collected from a large surface mine in Arizona state,USA.The results have shown that there is a good agreement between the actual and estimated values of investigated parameters. 相似文献
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以采矿业在深沪两市上市的67家 A 股上市公司为样本,对样本公司从2010年到2012年的社会责任与企业绩效进行了实证分析。分析结果表明,采矿业社会责任与企业绩效之间具有线性关系;债权人责任、股东责任、国家责任与企业绩效显著正相关;员工责任、社会责任、环境责任与企业绩效具有相关性。 相似文献
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添加微量稀土元素改善矿用硬质合金性能 总被引:2,自引:0,他引:2
此文研究了添加微量稀土元素对矿用硬质含金性能的影响。研究表明,添加一定量一定形态的稀土元素,能提高矿用硬质合会使用寿命,提高合金抗奇强度和抗冲击动性,增加合会的热塑性和高温强韧性,而对硬度、密度、磁力没有多大影响。 相似文献
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