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Stability mechanism and control of the pumpable supports in longwall recovery room

International Journal of Mining Science and Technology 2024年第07期 957-974页

作者： Dong zhang Jianbiao Bai Zhijun Tian zizheng zhang Yonghong Guo Rui Wang Ying Xu Hao Fu Shuai Yan Min Deng Shuaigang Liu State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology Key Laboratory of Xinjiang Coal Resources Green Mining Xinjiang Key Laboratory of Coal-bearing Resources Exploration and ExploitationXinjiang Engineering Research Center of Green Intelligent Coal MiningXinjiang Institute of Engineering Work Safety Key Laboratory on Prevention and Control of Gas and Roof Disasters for Southern Goal Mines Hunan Provincial Key Laboratory of Safe Mining Techniques of Coal MinesHunan University of Science and Technology School of Mines China University of Mining and Technology

The load-bearing performance （LBP） of pumpable supports （PPS） is crucial for the stability of longwall pre-driven recovery room （PRR） surrounding ***,the unbalanced bearing coefficient （UBC）of the PPS （undertaking unequal load along the mining direction） has not been investigated.A mechanical model of the PRR was established,considering the main roof cantilever beam structure,to derive an assessment formula for the load,the failure criteria,and the UBC of the ***,the generation mechanisms,and influencing factors of the UBC were *** sensitivity analysis shows that the main roof hanging length （l2） and the spacing between the PPS （r） significantly impact the UBC.A novel design of the PPS and the coupling control technology were proposed and applied to reduce the UBC of the PPS in the adjacent longwall *** results showed no failure of the PPS at the test site,with the UBC （ζ） reduced to 1.1 consistent with the design value （1.15） basically,fully utilizing the collaborative LBP of the ***,the maximum roof-to-floor convergence of the PRR was 234 mm,effectively controlling the stability of the surrounding rock of the PRR and ensuring the mining equipment recovery.

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Stability mechanism and control of the pumpable supports in longwall recovery room

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International Journal of Mining Science and Technology 2024年第7期34卷 957-974页

作者： zhang, Dong Bai, Jianbiao zhang, zizheng Wang, Rui Xu, Ying Fu, Hao Yan, Shuai Deng, Min Liu, Shuaigang State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology Xuzhou 221116 China Key Laboratory of Xinjiang Coal Resources Green Mining Xinjiang Key Laboratory of Coal-bearing Resources Exploration and Exploitation Xinjiang Engineering Research Center of Green Intelligent Coal Mining Xinjiang Institute of Engineering Urumqi 830023 China Work Safety Key Laboratory on Prevention and Control of Gas and Roof Disasters for Southern Goal Mines Hunan Provincial Key Laboratory of Safe Mining Techniques of Coal Mines Hunan University of Science and Technology Xiangtan 411201 China School of Mines China University of Mining and Technology Xuzhou 221116 China

The load-bearing performance (LBP) of pumpable supports (PPS) is crucial for the stability of longwall pre-driven recovery room (PRR) surrounding rock. However, the unbalanced bearing coefficient (UBC)of the PPS (undertaking unequal load along the mining direction) has not been investigated. A mechanical model of the PRR was established, considering the main roof cantilever beam structure, to derive an assessment formula for the load, the failure criteria, and the UBC of the PPS. Subsequently, the generation mechanisms, and influencing factors of the UBC were revealed. Global sensitivity analysis shows that the main roof hanging length (l2) and the spacing between the PPS (r) significantly impact the UBC. A novel design of the PPS and the coupling control technology were proposed and applied to reduce the UBC of the PPS in the adjacent longwall PRR. Monitor results showed no failure of the PPS at the test site, with the UBC (ζ) reduced to 1.1 consistent with the design value (1.15) basically, fully utilizing the collaborative LBP of the PPS. Finally, the maximum roof-to-floor convergence of the PRR was 234 mm, effectively controlling the stability of the surrounding rock of the PRR and ensuring the mining equipment recovery. © 2024

关键词： Sensitivity analysis

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湖北省国土空间“三生”功能权衡特征及影响因素分析

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水土保持研究 2024年第2期31卷 354-366,378页

作者：刘俊祥张蕾刘格格张自正湖北大学资源环境学院区域开发与环境响应湖北省重点实验室武汉430062 湖北省规划设计研究总院有限责任公司武汉430064

[目的]阐明湖北省“三生”功能之间的关系及其影响因素对国土空间布局的作用,为优化国土空间开发保护格局提供理论支持。[方法]遵循“功能评价—关系量化—机制识别”的框架,基于格网尺度评价“三生”功能,采用均方根误差(RMSE)模型和... 详细信息

[目的]阐明湖北省“三生”功能之间的关系及其影响因素对国土空间布局的作用,为优化国土空间开发保护格局提供理论支持。[方法]遵循“功能评价—关系量化—机制识别”的框架,基于格网尺度评价“三生”功能,采用均方根误差(RMSE)模型和地理探测模型等方法分别探究了空间功能权衡关系的时空演变格局及其驱动因素,突破了既有研究对微观尺度上空间功能关系动态演变研究不足的局限。[结果](1)2000—2020年,区域生产功能和生活功能不断提高,其中武汉市“高”等和鄂西山区“低”等区域变化显著,分别扩张了538.54 km^(2),14207.47 km^(2);整体生态功能减弱,四大山区“高”等区域降低尤为凸显,年均减少1009.50 km^(2)。(2)研究期间,生产-生活功能权衡强度呈“Λ”形演变特征,空间布局呈“低值区扩张、高值区收缩”态势,尤以随州市中西部和武汉市主城区较为显著;生产-生态功能权衡强度和生活-生态功能权衡强度变化规律相似,均呈倒“N”字形演变趋势,但空间分布格局差异明显,分别呈“中间高、四周低”的分布规律和中心-外围的空间布局。(3)2000—2005年、2005—2010年、2010—2015年和2015—2020年,“一主两副”主城区、武汉城市圈部分县区和鄂西山区生产-生活功能权衡指数的动态变化尤为凸显;生产-生态功能权衡指数变化和生活-生态功能权衡指数变化显著区主要分布在湖北省四大山区和江汉平原部分县区。(4)人口密度、GDP和人类活动强度是国土空间功能权衡关系的主要驱动因子。[结论]湖北省“三生”功能之间协同水平整体呈提升态势,社会经济活动对“三生”功能协调发展的影响较大,后续应因地制宜加强国土空间调控与管理。

关键词：国土空间权衡强度功能测算时空演变湖北省

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产教研深度融合的资源环境类专业人才培养体系的构建与实践

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当代教育理论与实践 2024年第2期16卷 63-69页

作者：李青锋张自政湖南科技大学资源环境与安全工程学院湖南湘潭411201

资源开发必须尊重自然、顺应自然、保护自然。资源与环境类专业人才培养必须构建跨学科、产教研深度融合的“大绿色”培养体系。为提高学生解决复杂工程问题能力、创新创业能力、伦理思辨能力、交叉学科知识融合能力和职业素养,建立了... 详细信息

资源开发必须尊重自然、顺应自然、保护自然。资源与环境类专业人才培养必须构建跨学科、产教研深度融合的“大绿色”培养体系。为提高学生解决复杂工程问题能力、创新创业能力、伦理思辨能力、交叉学科知识融合能力和职业素养,建立了资源环境类人才全方位全过程协同育人模式,并基于复合知识结构构建了一体化课程体系。同时,从价值引领、知识传授、创新能力培养、跨学科综合实习四个方面进行资源环境类专业教育教学探索。实践表明,构建多学科交叉、产教研深度融合的资源环境类人才培养机制是必然选择。

关键词：产教融合教研融合资源环境跨学科人才培养

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Stability control of gob-side entry retained under the gob with close distance coal seams

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International Journal of Mining Science and Technology 2021年第2期31卷 321-332页

作者： zizheng zhang Min Deng Jianbiao Bai Shuai Yan Xianyang Yu Work Safety Key Lab on Prevention and Control of Gas and Roof Disasters for Southern Coal Mines Hunan Provincial Key Laboratory of Safe Mining Techniques of Coal MinesHunan University of Science and TechnologyXiangtan 411201China State Key Laboratory of Coal Resources and Safe Mining China University of Mining and TechnologyXuzhou 221116China Jiangsu Engineering Laboratory of Mine Earthquake Monitoring and Prevention School of MinesChina University of Mining and TechnologyXuzhou 221116China

In multi-seam mining,the interlayer rock strata between the upper coal seam(UCS)and the lower coal seam(LCS)appear damage and strength weakening after mining the *** stability control of the gob-side entry retaining(GER)under the gob with close distance coal seams(CDCS)is faced with difficulties due to little attention to GER under this *** paper focuses on surrounding rock stability control and technical parameters design for GER under the gob with *** floor rock strata damage characteristics after mining the UCS is first evaluated and the damage factor of the interlayer rock strata below the UCS is also ***,a structural mechanics model of GER surrounding rock is set up to obtain the main design parameters of the side-roadway backfill body(SBB)including the maximum and minimum SBB width calculation *** optimal SBB width and the water-to-cement ratio of high water quick-setting material(HWQM)to construct the SBB are determined as 1.2 m and 1.5:1.0,***,engineering trial tests of GER are successfully carried out at#5210 track transportation roadway of Xingwu *** results can guide GER design under similar mining and geological conditions.

关键词： Gob-side entry retaining Close distance coal seams Damage factor Interlayer rock strata Side-roadway backfill body

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Study on gob-side entry retaining in fully-mechanized longwall with top-coal caving and its application

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International Journal of Mining Science and Technology 2015年第3期25卷 503-510页

作者： Su Hai Bai Jianbiao Yan Shuai Chen Yong zhang zizheng School of Resources and Safety Engineering China University of Mining and Technology Yuwu Coal Co. Ltd Shanxi Lu’an Mining Group School of Mines China University of Mining and Technology State Key Laboratory of Coal Resources and Safe Mining China University of Mining and Technology

Based on the engineering background of gob-side entry retaining in fully-mechanized longwall with top coal caving(GER-FLTC) on N2105 working face of Yuwu coal mine, by adopting the methods of theoretical analysis and numerical calculation, the control techniques of surrounding rocks in GER-FLTC working face are studied in this paper. The two main difficulties of stability of surrounding rocks at gob-side retained entry in fully-mechanized longwall working face are the stability control of top coal and control of large deformation of GER-FLTC working face. Interaction mechanical model between roofing and roadside backfilling in GER-FLTC is established and the equations for the calculation of roof-cutting resistance of roadside backfilling are derived. Results of numerical calculation show that the damage zones of top coal can be categorized into the delaminating zone of top coal above the backfilling, tensile damage zone of top coal above the retained roadway and shear damage zone of the upper rib of the solid coal. Stability control of top coal is the critical part to success of GER-FLTC. With consideration of large deformation of surrounding rocks of gob-side retained entry in fully-mechanized longwall, the support technique of‘‘roofing control and wall strengthening'' is proposed where high strength and highly prestressed anchor rods and diagonal tensile anchor cables support are used for top coal, high strength and highly prestressed yielding anchor rod support is used for solid coal and roadside prestressed load-carrying backfilling is constructed by high-water material, in order to maintain the integrity of the top coal, transfer load, high resistance yielding load-carrying of solid coal, roof-cutting of roadside backfilling and support,and to achieve GER-FLTC. Results from this study are successfully applied in engineering practice.

关键词： Gob-side entry retaining in fully-mechanized longwan with top coal caving Stability control of top coalLarge deformation control Roofing control and wall strengthening

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近距离煤层下煤层巷道合理布置及分级支护技术研究

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煤炭技术 2024年第8期43卷 114-119页

作者：刘义孟张自政王克伟柏建彪覃疏捷山西省中阳荣欣焦化有限公司山西吕梁033401 湖南科技大学资源环境与安全工程学院湖南湘潭411201 中国矿业大学矿业工程学院江苏徐州221116

为解决近距离煤层下煤层巷道合理布置及支护难题,以高家庄煤矿4201工作面回采巷道为工程背景,综合采用现场调研、理论分析、数值计算和工业性试验的方法,分析了3#煤层开采后底板岩层损伤特征、底板应力演化规律,确定了4#煤层首采工作面... 详细信息

为解决近距离煤层下煤层巷道合理布置及支护难题,以高家庄煤矿4201工作面回采巷道为工程背景,综合采用现场调研、理论分析、数值计算和工业性试验的方法,分析了3#煤层开采后底板岩层损伤特征、底板应力演化规律,确定了4#煤层首采工作面巷道采用内错布置方式,水平错距6 m。根据层间距变化,提出了2.8 m层间距以下采用“全锚杆+架棚”、2.8~3.3 m采用“帮锚杆+顶板短锚索+架棚”、层间距3.3 m以上采用“帮锚杆+顶板长/短锚索”等分级支护方案。矿压监测结果表明:巷道最大变形为顶板下沉,无论哪种层间距条件下均不超过100 mm,围岩控制效果好,保证了近距离煤层采空区下巷道的稳定性。

关键词：近距离煤层采空区锚索支护分级支护

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Contact engineering for temperature stability improvement of Bi-contacted MoS2 field effect transistors

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Science China(Information Sciences) 2024年第06期67卷 172-179页

作者： zizheng LIU Qing zhang Xiaohe HUANG Chunsen LIU Peng ZHOU State Key Laboratory of Integrated Chip and Systems School of MicroelectronicsZhangjiang Fudan International Innovation CenterFudan University Frontier Institute of Chip and System Shanghai Key Lab for Future Computing Hardware and SystemFudan University Shaoxin Laboratory

Semimetallic bismuth（Bi） is one of the most effective strategies for reducing the contact resistance of two-dimensional transition metal dichalcogenide field effect transistors（FETs）. However, the low melting point of Bi contact（271.5℃） limits its reliable applications. In this study, we demonstrated that the temperature stability of Bi-contacted electrodes could be improved by inserting a high-melting point semimetallic antimony（Sb） between the Bi contacting layer and the gold（Au） capping layer. The proposed Bi/Sb/Au contact electrodes tended to form a metal mixture with a continuous surface during the heating process（Voids appeared on the surface of the Bi/Au contact electrodes after heating at 120℃）. Because of the improved contacting layer formed by the semimetal Bi/Sb alloy, the fabricated Bi/Sb/Au-contacted molybdenum sulfide（MoS2） FETs with different gate lengths demonstrated higher on-state current stability after heating treatment than the Bi/Au contact. Because of the Bi/Sb/Au contact and poly（methyl methacrylate） package, the MoS2FETs demonstrated time stability of at least two months from the almost unchanged transfer characteristics. The electrical stability indicates that the insertion of semimetallic Sb is a promising technology for reliable Bi-based contact.

关键词： temperature stability semimetallic bismuth contact semimetallic antimony contact MoS$_{2}$ FETs time stability

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How do the landslide and non-landslide sampling strategies impact landslide susceptibility assessment? d A catchment-scale case study from China

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 877-894页

作者： zizheng Guo Bixia Tian Yuhang Zhu Jun He Taili zhang School of Civil and Transportation Engineering Hebei University of TechnologyTianjin300401China Hebei Key Laboratory of Earthquake Disaster Prevention and Risk Assessment Sanhe065201China Faculty of Engineering China University of GeosciencesWuhan430074China Nanjing Center China Geological SurveyMinistry of Natural ResourcesNanjing210016China

The aim of this study is to investigate the impacts of the sampling strategy of landslide and non-landslide on the performance of landslide susceptibility assessment(LSA).The study area is the Feiyun catchment in Wenzhou City,Southeast *** types of landslides samples,combined with seven non-landslide sampling strategies,resulted in a total of 14 *** corresponding landslide susceptibility map(LSM)for each scenario was generated using the random forest *** receiver operating characteristic(ROC)curve and statistical indicators were calculated and used to assess the impact of the dataset sampling *** results showed that higher accuracies were achieved when using the landslide core as positive samples,combined with non-landslide sampling from the very low zone or buffer *** results reveal the influence of landslide and non-landslide sampling strategies on the accuracy of LSA,which provides a reference for subsequent researchers aiming to obtain a more reasonable LSM.

关键词： Landslide susceptibility Sampling strategy Machine learning Random forest China

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Clinical experiences with 20 cases of single-direction thoracoscopic lobectomy and systematic lymph node dissection for peripheral NSCLC

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Journal of Medical Colleges of PLA(China) 2012年第4期27卷 226-232页

作者： zhang zizheng Liu Hanyun Department of Thoracic Surgery Affiliated Meizhou HospitalMedical CollegeSun Yat-sen University

Objective: To evaluate the safety, efficacy, feasibility of single-direction thoracoscopic lobectomy for peripheral lung cancer. Methods: From December 2009 to March 2011, 20 patients with peripheral lung cancer were treated with single-direction thoracoscopic lobectomy and systemic lymph nodes dissection. Results: Surgeries were successfully performed. No significant complications occurred perioperatively. The average operation time was 193 min, the average blood loss was 234 ml, the average duration of drainage was 6 d, the postoperative hospital stay was 12 d, and the average number of lymph nodes dissected was 16. Conclusion: Single-direction thoracoscopic lobectomy is feasible and safe in the treatment of peripheral lung cancer and can simplify the surgical procedures.

关键词： Video-assisted thoracoscopic surgery Peripheral lung cancer Lymph node dissection

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