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Environmental risk assessment of industrial byproduct gypsum utilized for flling abandoned mines

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International Journal of Coal Science & technology 2022年第4期9卷 214-225页

作者： XueHong Du Xiangdong Li Qiyan Feng Lei Meng Yue Sun School of Environment Science and Spatial Informatics China University of Mining and TechnologyXuzhou 221116China The National and Local Joint Engineering Laboratory of Internet Application Technology On Mine China University of Mining and TechnologyXuzhou 221008Jiangsu ProvinceChina IoT Perception mine Research Center China University of Mining and TechnologyXuzhou 221008Jiangsu ProvinceChina Jiangsu Vocational Institute of Architectural technology No.26 Xueyuan RoadXuzhou 221433China

In response to the basic policy of green and low-carbon circular development to solve resource,environmental and ecological problems,gypsum is considered to be a flling material for mine backflling.To explore the potential risks of gypsum to the groundwater environment due to the backflling of abandoned mines,a sequential batch leaching experiment was carried out in this paper,which used three types of industrial waste gypsum,namely,phosphorus gypsum(PG),titanium gypsum(TG)and fue gas desulfurization gypsum(FGDG).COMSOL Multiphysics 5.4 software was used to simulate and solve the migration process of the leached metal elements in the mine foor when these three gypsum types were used as flling materials to observe the concentration distributions and difusion distances of the metal elements from these three gypsum types in the mine foor.The results show that(1)during repeated contact of the three types of industrial waste gypsum with the leaching medium,the pH levels changed,and the changes in pH afected the leaching patterns for the heavy metal elements in the gypsum.(2)Based on the concentrations of the metal elements that were leached from the three types of gypsum,it can be determined that these three types of gypsum are not classifed as hazardous solid wastes,but they cannot be ruled out with regard to their risk to the groundwater environment when they are used as mine flling materials.(3)When the three types of gypsum are used as flling materials,the concentration distributions of the metal elements and their migration distances all exhibit signifcant changes over time.The concentration distributions,difusion rates and migration distances of the metal elements from the diferent gypsum types are afected by their initial concentrations in the leachate.The maximum migration distances of Zn in the foor from the PG,FGDG and TG are 8.2,8.1 and 7.5 m,respectively.

关键词： Industrial solid waste gypsum Coal mine back-flling Leaching of metal elements Patterns of migration

面向大规模中文文本分类的朴素贝叶斯并行Spark算法（英文）

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Journal of Central South University 2019年第1期26卷 1-12页

作者：刘鹏赵慧含滕家雨仰彦妍刘亚峰朱宗卫 internet of Things Perception mine Research Centre China University of Mining and Technology national and local joint engineering laboratory of internet application technology on mine School of Information and Control engineering China University of Mining and Technology Communication Division NARI Technology Co. Ltd. Suzhou Institute of University of Science and technology of China

针对互联网中中文文本数据量激增使得对其作分类运算的处理时间显著延长的问题,提出并实现了一种基于内存计算模型Spark的并行朴素贝叶斯中文文本分类算法,主要利用弹性分布数据集编程模型,实现了朴素贝叶斯分类器训练过程和预测过程的... 详细信息

针对互联网中中文文本数据量激增使得对其作分类运算的处理时间显著延长的问题,提出并实现了一种基于内存计算模型Spark的并行朴素贝叶斯中文文本分类算法,主要利用弹性分布数据集编程模型,实现了朴素贝叶斯分类器训练过程和预测过程的全程并行化算法。为便于比较,同时实现了基于Hadoop-MapReduce的并行朴素贝叶斯版本。实验结果表明,在相同计算环境下,对同一数据量的中文文本集,基于Spark的朴素贝叶斯中文文本分类并行化算法在加速比、扩展性等主要指标上明显优于基于Hadoop的实现,因此能更好地满足大规模中文文本数据挖掘的要求。

关键词：中文文本分类朴素贝叶斯 Spark Hadoop 弹性分布式数据集并行化

Formation Principle and Characteristics of Self‑Supercharging Pulsed Water Jet

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Chinese Journal of Mechanical engineering 2022年第3期35卷 250-263页

作者： Zhaolong Ge Yuanfei Ling Jiren Tang Yiyu Lu Yangkai Zhang Lei Wang Qi Yao State Key laboratory of Coal mine Disaster Dynamics and Control Chongqing UniversityChongqing 400030China national&local joint engineering laboratory of Gas Drainage in Complex Coal Seam Chongqing UniversityChongqing 400030China College of Source and Safety Chongqing UniversityChongqing 400030China

High-pressure pulsed water jet technology has considerable development potential in the field of rock fragmentation.To overcome the shortcomings of existing pulsed jets,a self-supercharging pulsed water jet(SSPWJ)generation method is proposed,which is based on the theory of the pulsed water jet and the principle of hydraulic boosting.The proposed method changes the flow direction of the fluid medium through the valve core to make the piston reciprocate in the cylinder and relies on the effective area difference between the front and rear chambers in the stroke stage of the piston to realize the organic combination of“pulse”and“supercharging”of the jet,thus forming an SSPWJ.On the basis of the formation principle of the SSPWJ,a SSPWJ testing platform was constructed,and tests were performed on the jet pressure acquisition,morphology capture,and granite erosion.Both the jet pressure and the jet morphology exhibited periodic changes,and a higher pulse pressure was obtained at lower inlet pressure.The error of the pressure ratio calculated according to the experimental results waslocal flaky exfoliation was observed when the granite surface was eroded.The results of this study lay the foundation for enriching the theory of pulsed jet generation and expanding its application range.

关键词： Pulsed water jet Self-supercharging Pulse parameters Jet morphology Granite breaking

Multi-parameter numerical simulation of dynamic monitoring of rock deformation in deep mining

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International Journal of Mining Science and technology 2016年第5期26卷 851-855页

作者： Li Juanjuan Hu Mingshun Ding Enjie Kong Wei Pan Dongming Chen Shenen IoT Perception mine Research Center China University of Mining ＆ Technology Xuzhou 221008 China The national and local joint engineering laboratory of lnternet application technology on mine China University of Mining ＆ Technology Xuzhou 221008 China School of Resources and Geosciences China University of Mining ＆ Technology Xuzhou 221116 China City Exploring and Surveying Institute ofJinan Jinan 250013 China Department of Civil engineering University of North Carolina at Charlotte Charlotte 28223 USA

The level of deformation development of surrounding rocks is a vital predictor to evaluate impending coal mine disasters and it is important to establish accurate measurements of the deformed status to ensure coal mine safety. Traditional deformation monitoring methods are mostly based on single parameter, in this paper, multiple approaches are integrated: firstly, both electric and elastic models are established,from which electric field distribution and seismic wave recording are calculated and finally, the resistivity profiles and source position information are determined using inversion methods, from which then the deformation and failure of mine floor are evaluated. According to the inversion results of both electric and seismic field signals, multiple-parameter dynamic monitoring of surrounding rock deformation in deep mine can be performed. The methodology is validated using numerical simulation results which shows that the multi-parameter dynamic monitoring methods have better results for surrounding rock deformation in deep mine monitoring than single parameter methods.

关键词： Dynamic monitoring Electric numerical simulation Elastic numerical simulation Inversion methods

Effect of adsorption-induced matrix swelling on coal permeability evolution of micro-fracture with the real geometry

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Petroleum Science 2021年第4期18卷 1143-1152页

作者： Ming-Yao Wei Jishan Liu Ying-Ke Liu Zhang-Hao Liu Derek Elsworth national and local joint engineering laboratory of internet application technology on mine IoT Perception Mine Research CenterChina University of Mining and TechnologyXuzhou 221116JiangsuChina State Key laboratory of Coal and CBM Co-Mining Jincheng 048012ShanxiChina School of engineering The University of Western Australia35 Stirling HighwayPerthWA6009Australia Faculty of Safety engineering China University of Mining and TechnologyXuzhou 221116JiangsuChina Institute of Rock and Soil Mechanics Chinese Academy of SciencesWuhan 430071HubeiChina Department of Energy and mineral engineering G3 Center and Energy InstituteThe Pennsylvania State UniversityUniversity ParkPA16802USA

Gas transport in coal induces effective stress variation,matrix swelling/shrinkage,and significantly affects matrix and fracture deformation,resulting in porosity and permeability evolution.However,the heterogeneity and anisotropy of coal are neglected in dual porosity models,which can lead to the deviation from the real physical mechanisms.To uncover the permeability evolution,especially the influence of dynamic matrix-fracture interaction for real fracture distribution,advanced virtual simulation is proposed.In this study,real fracture geometry is taken into account in the physical model based on the CT-scan image,while the mathematical models for coal deformation and gas flow are established.Our calculations are verified against a long-term experimental data under the same boundary condition.Accordingly,the real matrix-fracture interaction caused by adsorption-induced matrix deformation has been visually exhibited,and some new insight into the behavior of fracture permeability in real materials is offered.The results indicate the non-uniform distribution of fracture geometry is responsible for the nonmonotonic change of permeability.It also found that injection pressure,Langmuir strain constant and initial matrix permeability have important influences on the fracture permeability evolution.This research provides valuable insight into the understanding of the permeability change for the real fracture spatial distribution in coal.

关键词： Geometry distribution Adsorption swelling Coal permeability Matrix-fracture interaction

Development and validation of THM coupling model of methane-containing coal

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International Journal of Mining Science and technology 2012年第6期22卷 868-872页

作者： Tao Yunqi Xu Jiang Liu Dong Liang Yongqing State Key laboratory of Coal mine Disaster Dynamics and Control Chongqing University State and local joint engineering laboratory of Methane Drainage in Complex Coal Gas Seam Chongqing University

Based on nine necessary basic assumptions for THM coupling model,this research comprehensively applied the theories of elastic mechanics,seepage mechanics and heat transfer,and established a real three-field and two-way coupled mathematical model to reveal the connections among seepage field,deformation field and temperature field within the system of methane-containing coal.In comparison between numerical and analytical solutions,the coupling modeling for THM of methane-containing coal was proved to be correct by model application in the physical simulation experiment of coal and gas outburst.The model established in this paper was the improvement of traditional seepage theory of methane-containing coal and fluid-solid coupled model theory,which can be widely used in prevention of coal and gas outburst as well as exploitation of coal bed methane.

关键词： Coal containing methane Temperature field Seepage field Stress field Fluid-solid-heat coupling

Hexagonally ordered microbowl arrays decorated with ultrathin CuInS_(2) nanosheets for enhanced photoelectrochemical performance

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Journal of Energy Chemistry 2020年第12期29卷 134-142页

作者： Ming Li Le Chen Yanjie Su Huan Yin Kexiang Hu State Key laboratory of Transducer technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai 200050China School of Electronic engineering and Automation Guilin University of Electronic TechnologyKey Laboratory of Optoelectronic Information Processing of Guangxi Colleges and Uniy/ersitiesGuilin 541004GuangxiChina Key laboratory for Thin Film and Microfabrication of the Ministry of Education Department of Micro/Nano ElectronicsSchool of ElectronicsInformation and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China national and local joint engineering laboratory of internet technology on mine School of Information and Control EngineeringChina University of Mining and TechnologyXuzhou 221008JiangsuChina School of Physics and Telecommunication engineering Guangxi Colleges and Universities Key Lab of Complex System Optimization and Big Data ProcessingYulin Normal UniversityYulin 537400GuangxiChina

This paper demonstrates the design and fabrication of three-dimensional(3 D) hexagonally ordered microbowl arrays(MBAs) decorated with Cu In S2 nanosheets for enhanced photoelectrochemical(PEC) performance. The 3 D MBAs are fabricated by a micro-fabrication technique. The ultrathin CuInS2 nanosheets are grown on the 3 D electrodes by solvothermal transformation of Cu film. The photocurrent density of 3 D photocathode(CuInS2@MBAs) is about two times higher than that of the planar counterpart(CuInS2@Planar). The improved PEC performance can be ascribed to the elevated light trapping ability and the increased surface area for loading photocatalysts. In addition, CdS quantum dots as cocatalysts are modified onto the Cu In S2 nanosheets to further enhance the PEC activity because the formed p-n heterojunction can accelerate the separation of photogenerated carriers. As a result, the 3 D photocathode of CuInS2/CdS@MBAs shows an optimal incident photon to current efficiency of 10% at the wavelength of400 nm. It is believed that this work can be generalized to design other hierarchical 3 D photoelectrodes for improved solar water splitting.

关键词： Microbowl array CuInS_(2) Nanosheet Photocathode Photoelectrochemical performance

Partition airflow varying features of chaos-theory-based coalmine ventilation system and related safety forecasting and forewarning system

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International Journal of Mining Science and technology 2017年第2期27卷 269-275页

作者： Zhang Xiaoqiang Cheng Weimin Zhang Qin Yang Xinxiang Du Wenzhou Key laboratory of Ministry of Education for mine Disaster Prevention and Control Shandong University of Sdence and TechnologyQingdao 266590China College of Mining and Safety engineering Shandong University of Science and technology Qingdao 266590China

To realize real-time monitoring and short-term forecasting and forewarning of coalmine ventilation systems(CVS), in this paper, we first established a joint surface and underground CVS safety management system consisting of main ventilation fan, safety-partition linked passageways, and air-required locations. We then applied chaos theory to identify the air quantity and gas concentration of underground partition boundaries, and adopted a fixed data quantity, multi-step progressive, weighted first-order local-domain method to setup a chaos prediction model and a CVS safety forecasting and forewarning system formed by the normal change level, orange forewarning level, and red alarm level. We next conduct the on-field application of the system in a coalmine in Jining, Shandong, China. The results showed that (1) in the statistical scale of 5 min, the changes in both air quantity and gas concentration along CVS partition airflow boundaries were characteristic of chaos and could be used for short-term chaos prediction, and the latter was more chaotic than the former;(2) the setup chaos prediction model had a higher prediction precision and the established safety prediction system could not only predict the variation in CVS stability but also reflect the rationality of underground mining intensity. Thus, this CVS safety forecasting and forewarning system is of better application value.

关键词：安全预警系统矿井通风系统混沌理论安全预测气流变化安全分区加权一阶局域法特征

Low-field NMR application in the characterization of CO_(2)geological storage and utilization related to shale gas reservoirs:a brief review

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Frontiers of Earth Science 2023年第3期17卷 739-751页

作者： Zhaohui LU Ke LI Xingbing LIU Peng ZHAO Jun LIU national and local joint engineering Research Center of Shale Gas Exploration and Development Chongqing Institute of Geology and Mineral ResourceChongqing 401120China Key laboratory of Shale Gas Exploration(Ministry of Natural Resources) Chongqing Institute of Geology and Mineral ResourcesChongqing 401120China MOE Key laboratory of Deep Earth Science and engineering Institute of New Energy and Low-Carbon TechnologySichuan UniversityChengdu 610065China State Key laboratory of Coal mine Disaster Dynamics and Control School of Resources and Safety EngineeringChongqing UniversityChongqing 400044China Chongqing Institute of Geological Survey Chongqing 401122China

CO_(2)geological storage and utilization(CGSU)is considered a far-reaching technique to meet the demand of increasing energy supply and decreasing CO_(2)emissions.For CGSUs related to shale gas reservoirs,experimental investigations have attracted variable methodologies,among which low-field NMR(LF-NMR)is a promising method and is playing an increasingly key role in reservoir characterization.Herein,the application of this nondestructive,sensitive,and quick LF-NMR technique in characterizing CGSU behavior in shale gas reservoirs is reviewed.First,the basic principle of LF-NMR for 1H-fluid detection is introduced,which is the theoretical foundation of the reviewed achievements in this paper.Then,the reviewed works are related to the LF-NMR-based measurements of CH_(4)adsorption capacity and the CO_(2)-CH_(4)interaction in shale,as well as the performance on CO_(2)sequestration and simultaneous enhanced gas recovery from shale.Basically,the reviewed achievements have exhibited a large potential for LF-NMR application in CGSUs related to shale gas reservoirs,although some limitations and deficiencies still need to be improved.Accordingly,some suggestions are proposed for a more responsible development of the LF-NMR technique.Hopefully,this review is helpful in promoting the expanding application of the LF-NMR technique in CGSU implementation in shale gas reservoirs.

关键词： CO_(2)/CH_(4)competitive adsorption shale gas reservoir CO_(2)geological storage gas recovery enhancement low-field NMR