Journal of China University of Mining and Technology最新文献_第9页

Improved shielding and filtering applied to immunity enhancement of underground gas sensors 改进的屏蔽和滤波技术用于提高地下气体传感器的抗扰度

Journal of China University of Mining and Technology Pub Date : 2008-06-01 DOI: 10.1016/S1006-1266(08)60046-2

Ji-ping SUN , Feng-ying MA

{"title":"Improved shielding and filtering applied to immunity enhancement of underground gas sensors","authors":"Ji-ping SUN , Feng-ying MA","doi":"10.1016/S1006-1266(08)60046-2","DOIUrl":"10.1016/S1006-1266(08)60046-2","url":null,"abstract":"<div><p>In order to eliminate false alarms, issued by gas sensors in coal mining, caused by Electromagnetic Interference (EMI), both computer simulation and field measurements were introduced to analyze the underground EMI distribution. A simplified model of a sensor with metal enclosure was established and the effects of shielding properties about the enclosure aperture were studied. Because the haulage motor is the moving EMI source, varying with time, the onsite flameproof measuring instruments cannot accomplish synchronous measurements of electromagnetic field vectors. To simplify the field measurements, two sensors, one with a lead and the other without a lead, were chosen to conduct the contrasting measurements. The EMI current caused by the perforation lead was comparatively strong and therefore nickel zinc ferrite beads were used to cut off the EMI propagation paths. The peak value of the interference current was reduced by 20%–70% with the beads. After switching on the sensor power, the sensors still occasionally gave false alarms when the switch of nearby large-scale electric equipment was operated. A complex EMI filter was used and the EMI attenuated markedly. The running results demonstrated that false alarms had been eliminated. We conclude that the improved shielding and filtering are highly significant in enhancing the immunity of the gas sensor.</p></div>","PeriodicalId":15315,"journal":{"name":"Journal of China University of Mining and Technology","volume":"18 2","pages":"Pages 220-223"},"PeriodicalIF":0.0,"publicationDate":"2008-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-1266(08)60046-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74300842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Kinetics of the leaching of TiO2 from Ti-bearing blast furnace slag 含钛高炉渣中TiO2浸出动力学研究

Journal of China University of Mining and Technology Pub Date : 2008-06-01 DOI: 10.1016/S1006-1266(08)60058-9

Xiao-hua LIU , Guo-sheng GAI , Yu-fen YANG , Zhi-tong SUI , Li LI , Jian-xia FU

引用次数: 42

Competitive adsorption of heavy metal ions on peat 泥炭对重金属离子的竞争吸附

Journal of China University of Mining and Technology Pub Date : 2008-06-01 DOI: 10.1016/S1006-1266(08)60054-1

Zhi-rong LIU , Li-min ZHOU , Peng WEI , Kai ZENG , Chuan-xi WEN , Hui-hua LAN

引用次数: 57

Extracting mining subsidence land from remote sensing images based on domain knowledge 基于领域知识的遥感影像开采沉陷地提取

Journal of China University of Mining and Technology Pub Date : 2008-06-01 DOI: 10.1016/S1006-1266(08)60036-X

Xing-feng WANG , Yun-jia WANG , Tai HUANG

引用次数: 9

Application of cepstral analysis to thin beds 倒谱分析在薄层中的应用

Journal of China University of Mining and Technology Pub Date : 2008-06-01 DOI: 10.1016/S1006-1266(08)60049-8

Chun-yuan LIU , Sheng-feng XU , Jian-hua YUE , Xiu-cheng WEI

引用次数: 3

Focal mechanism caused by fracture or burst of a coal pillar 煤柱破裂或爆裂引起的震源机制

Journal of China University of Mining and Technology Pub Date : 2008-06-01 DOI: 10.1016/S1006-1266(08)60033-4

An-ye CAO, Lin-ming DOU, Guo-xiang CHEN, Si-yuan GONG, Yu-gang WANG, Zhi-hua LI

{"title":"Focal mechanism caused by fracture or burst of a coal pillar","authors":"An-ye CAO, Lin-ming DOU, Guo-xiang CHEN, Si-yuan GONG, Yu-gang WANG, Zhi-hua LI","doi":"10.1016/S1006-1266(08)60033-4","DOIUrl":"10.1016/S1006-1266(08)60033-4","url":null,"abstract":"<div><p>As a regional, real-time and dynamic method, microseismic monitoring technology is quite an appropriate technology for forecasting geological hazards, such as rock bursts, mine tremors, coal and gas outbursts and can even be used to prevent or at least reduce these disasters. The study of the focal mechanisms of different seismic sources is the prerequisite and basis for forecasting rock burst by microseismic monitoring technology. Based on the analysis on the mechanism and fracture course of coal pillars where rock bursts occur mostly, the equivalent point source model of the seismicity caused by a coal pillar was created. Given the model, the seismic displacement equation of a coal pillar was analyzed and the seismic mechanism was pointed out by seismic wave theory. The course of the fracture of the coal pillar was simulated closely in the laboratory and the equivalent microseismic signals of the fractures of the coal pillar were acquired using a TDS-6 experimental system. The results show that, by the pressure and friction of a medium near the seismic source, both a compression wave and a shear wave will be emitted and shear fracture will be induced at the moment of breakage. The results can be used to provide an academic basis to forecast and prevent rock bursts or tremors in a coal pillar.</p></div>","PeriodicalId":15315,"journal":{"name":"Journal of China University of Mining and Technology","volume":"18 2","pages":"Pages 153-158"},"PeriodicalIF":0.0,"publicationDate":"2008-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-1266(08)60033-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120263954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12

Size effect on compressive strength of reactive powder concrete 粒径对活性粉混凝土抗压强度的影响

Journal of China University of Mining and Technology Pub Date : 2008-06-01 DOI: 10.1016/S1006-1266(08)60059-0

Ming-zhe AN , Li-jun ZHANG , Quan-xin YI

引用次数: 47

Fracture evolution and pressure relief gas drainage from distant protected coal seams under an extremely thick key stratum 极厚关键层下远距离保护煤层裂隙演化与卸压瓦斯抽放

Journal of China University of Mining and Technology Pub Date : 2008-06-01 DOI: 10.1016/S1006-1266(08)60039-5

Liang WANG , Yuan-ping CHENG , Feng-rong LI , Hai-feng WANG , Hai-bo LIU

{"title":"Fracture evolution and pressure relief gas drainage from distant protected coal seams under an extremely thick key stratum","authors":"Liang WANG , Yuan-ping CHENG , Feng-rong LI , Hai-feng WANG , Hai-bo LIU","doi":"10.1016/S1006-1266(08)60039-5","DOIUrl":"10.1016/S1006-1266(08)60039-5","url":null,"abstract":"<div><p>When an extremely thick rock bed exists above a protected coal seam in the bending zone given the condition of a mining protective seam, this extremely thick rock bed controls the movement of the entire overlying stratum. This extremely thick rock bed, called a “main key stratum”, will not subside nor break for a long time, causing lower fractures and bed separations not to close and gas can migrate to the bed separation areas along the fractures. These bed separations become gas enrichment areas. By analyzing the rule of fracture evolution and gas migration under the main key stratum after the deep protective coal seam has been mined, we propose a new gas drainage method which uses bore holes, drilled through rock and coal seams at great depths for draining pressure relief gas. In this method, the bores are located at a high level suction roadway (we can also drill them in the drilling field located high in an air gateway). Given the practice in the Haizi mine, the gas drainage rate can reach 73% in the middle coal group, with a gas drainage radius over 100 m.</p></div>","PeriodicalId":15315,"journal":{"name":"Journal of China University of Mining and Technology","volume":"18 2","pages":"Pages 182-186"},"PeriodicalIF":0.0,"publicationDate":"2008-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-1266(08)60039-5","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80976043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 48

An intelligent system for calculating the scale of rational, enlarged production of an underground non-ferrous metal mine 地下有色金属矿山合理扩大生产规模的智能计算系统

Journal of China University of Mining and Technology Pub Date : 2008-06-01 DOI: 10.1016/S1006-1266(08)60045-0

Ming-gui ZHENG, Si-jing CAI

引用次数: 5

A forecasting and forewarning model for methane hazard in working face of coal mine based on LS-SVM 基于LS-SVM的煤矿工作面甲烷危害预测预警模型

Journal of China University of Mining and Technology Pub Date : 2008-06-01 DOI: 10.1016/S1006-1266(08)60037-1

Shu-gang CAO , Yan-bao LIU , Yan-ping WANG

{"title":"A forecasting and forewarning model for methane hazard in working face of coal mine based on LS-SVM","authors":"Shu-gang CAO , Yan-bao LIU , Yan-ping WANG","doi":"10.1016/S1006-1266(08)60037-1","DOIUrl":"10.1016/S1006-1266(08)60037-1","url":null,"abstract":"<div><p>To improve the precision and reliability in predicting methane hazard in working face of coal mine, we have proposed a forecasting and forewarning model for methane hazard based on the least square support vector (LS-SVM) multi-classifier and regression machine. For the forecasting model, the methane concentration can be considered as a nonlinear time series and the time series analysis method is adopted to predict the change in methane concentration using LS-SVM regression. For the forewarning model, which is based on the forecasting results, by the multi-classification method of LS-SVM, the methane hazard was identified to four grades: normal, attention, warning and danger. According to the forewarning results, corresponding measures are taken. The model was used to forecast and forewarn the K9 working face. The results obtained by LS-SVM regression show that the forecasting have a high precision and forewarning results based on a LS-SVM multi-classifier are credible. Therefore, it is an effective model building method for continuous prediction of methane concentration and hazard forewarning in working face.</p></div>","PeriodicalId":15315,"journal":{"name":"Journal of China University of Mining and Technology","volume":"18 2","pages":"Pages 172-176"},"PeriodicalIF":0.0,"publicationDate":"2008-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1006-1266(08)60037-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88340076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 57