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Testing method of rock structural plane using digital drilling

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第7期16卷 2563-2578页

作者： Qi Wang Yuncai Wang Bei Jiang hongke gao Fenglin Ma Dahu Zhai Songlin Cai State Key Laboratory for Tunnel Engineering China University of Mining and Technology(Beijing)Beijing100083China

The rock mass consists of rock blocks and structural planes,which can reduce its integrity and ***,accurately obtaining the characteristics of the rock mass structural plane is a prerequisite for evaluating stability and designing supports in underground ***,there are no effective testing methods for the characteristic parameters of the rock mass structural plane in underground *** paper presents the digital drilling technology as a new testing method of rock mass structural *** rock specimens with cracks of varying widths and angles were used to simulate the rock mass structural planes,and the multifunctional rock mass digital drilling test system was employed to carry out the digital drilling *** analysis focuses on the variation laws of drilling parameters,such as drilling pressure and drilling torque,affected by the characteristics of prefabricated cracks,and clarifies the degradation mechanism of rock equivalent compressive ***,an identification model for the characteristic parameters of rock mass structural planes during drilling is *** test results indicate that the average difference of the characteristics of prefabricated cracks identified by the equivalent compressive strength is 2.45and 0.82 mm,*** identification model while drilling is verified to be correct due to the high identification *** on this,a method for testing the characteristic parameters of the surrounding rock structural plane while drilling is *** research offers a theoretical and methodological foundation for precise in situ identification of structural planes of the surrounding rock in underground engineering.

关键词： Structural planes in the rock mass Digital drilling Drilling parameters Equivalent compressive strength Testing method

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极近距离煤层开采无煤柱自成巷控制方法研究

采矿与岩层控制工程学报 2024年第1期6卷 18-33页

作者：王琦刘寄婷江贝薛浩杰高红科蒋振华中国矿业大学(北京)隧道工程灾变防控与智能建养全国重点实验室北京100083 山东大学岩土工程中心山东济南250061

极近距离煤层传统长壁开采,受上层遗留煤柱和采空区垮落等因素的影响,下煤层开采过程中应力环境复杂、矿压显现剧烈,易诱发巷道围岩大变形。为解决上述问题,提出了极近距离条件下巷道定向切顶–约束高强支护无煤柱自成巷控制方法。通过... 详细信息

极近距离煤层传统长壁开采,受上层遗留煤柱和采空区垮落等因素的影响,下煤层开采过程中应力环境复杂、矿压显现剧烈,易诱发巷道围岩大变形。为解决上述问题,提出了极近距离条件下巷道定向切顶–约束高强支护无煤柱自成巷控制方法。通过顶板定向预裂切顶,主动改变顶板悬臂结构,切断采空区向巷道顶板的应力传递。充分利用矿山压力和岩体碎胀特性,取消煤柱留设,结合高强支护加强巷道顶板整体性,共同实现切顶自成巷。建立了极近距离煤层开采覆岩结构模型,计算了下煤层切顶自成巷巷旁支护阻力。以典型极近距离煤层为工程背景,开展了不同开采方法的数值试验对比研究,结果表明,提出的自成巷控制方法使巷道围岩应力降低59.8%,巷道顶板变形减少70.8%,并明确了极近距离煤层开采无煤柱自成巷控制机理。在此基础上,开展了典型极近距离煤层工程设计及现场应用研究,结果表明该方法有效降低了矿压显现程度,保证了自成巷的安全稳定控制。

关键词：极近距离煤层定向切顶卸压约束高强支护力学模型设计方法

Relationship between rock uniaxial compressive strength and digital core drilling parameters and its forecast method

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International Journal of Coal Science & Technology 2021年第4期8卷 605-613页

作者： hongke gao Qi Wang Bei Jiang Peng Zhang Zhenhua Jiang Yue Wang Geotechnical and Structural Engineering Research Center Shandong UniversityJinan 250061China State Key Laboratory for GeoMechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory for GeoMechanics and Deep Underground Engineering China University of Mining and TechnologyBeijing 100083China Shandong Tianqin Mining Machinery Equipment Co. Ltd.Yuncheng 274700China

The rock uniaxial compressive strength(UCS)is the basic parameter for support designs in underground *** particular,the rock UCS should be obtained rapidly for underground engineering with complex geological conditions,such as soft rock,fracture areas,and high stress,to adjust the excavation and support plan and ensure construction *** solve the problem of obtaining real-time rock UCS at engineering sites,a rock UCS forecast idea is proposed using digital core *** digital core drilling tests and uniaxial compression tests are performed based on the developed rock mass digital drilling *** results indicate that the drilling parameters are highly responsive to the rock *** on the cutting and fracture characteristics of the rock digital core drilling,the mechanical analysis of rock cutting provides the digital core drilling strength,and a quantitative relationship model(CDP-UCS model)for the digital core drilling parameters and rock UCS is ***,the digital core drilling-based rock UCS forecast method is proposed to provide a theoretical basis for continuous and quick testing of the surrounding rock UCS.

关键词： Digital core drilling Mechanical analysis Rock UCS Quantitative relationship model Forecast method

Thermal and mechanical behavior of casting copper alloy wheel during wheel and belt continuous casting process

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China Foundry 2024年第1期21卷 82-90页

作者： Kun gao Yan Peng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

To investigate the thermal and mechanical behavior of casting wheel,a two-dimensional thermoelastic-plastic finite element model was used to predict the temperature,stress and distortion distribution of the casting wheel during the wheel and belt continuous casting *** effects of grinding thickness and casting speed on the thermal and mechanical behaviors of the center of the hot face of the casting wheel were discussed in *** each rotation,the casting wheel passes through four different spray *** results show that the temperature distribution of the casting wheel in different spray zones is similar,the temperature of the hot face is the highest and the temperature reaches the peak in the spray zoneⅢ.The stress and distortion depend on the temperature distribution,and the maximum stress and distortion of the hot face are 358.2 MPa and 1.82 mm,*** temperature at the center of the hot face decreases with increasing grinding thickness and increases with increasing casting speed.

关键词： casting wheel finite element model grinding thickness casting speed hot face spray zones

Durable poly(binaphthyl-co-p-terphenyl piperidinium)-based anion exchange membranes with dual side chains

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Journal of Energy Chemistry 2024年第2期89卷 324-335,I0008页

作者： Weiting gao Xuelang gao Qiugen Zhang Aimei Zhu Qinglin Liu Department of Chemical&Biochemical Engineering Fujian Provincial Key Laboratory of Theoretical and Computational ChemistryThe College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005FujianChina Department of Chemistry Pohang University of Science and Technology(POSTECH)Pohang 790-784South Korea

Building well-developed ion-conductive highways is highly desirable for anion exchange membranes(AEMs).Grafting side chain is a highly effective approach for constructing a well-defined phaseseparated morphological structure and forming unblocked ion pathways in AEMs for fast ion *** of side chains can further enhance phase separation due to the superhydrophobic nature of fluorine ***,their electronic effect on the alkaline stability of side chains and membranes is rarely ***,fluorine-containing and fluorine-free side chains are introduced into the polyaromatic backbone in proper configuration to investigate the impact of the fluorine terminal group on the stability of the side chains and membrane *** poly(binaphthyl-co-p-terphenyl piperidinium)AEM(QBNp TP)has the highest molecular weight and most dimensional stability due to its favorable backbone arrangement among ortho-and meta-terphenyl based ***,by introducing both a fluorinated piperidinium side chain and a hexane chain into the p-terphenyl-based backbone,the prepared AEM(QBNp TP-QFC)presents an enhanced conductivity(150.6 m S cm^(-1))and a constrained swelling at 80℃.The electronic effect of fluorinated side chains is contemplated by experiments and *** results demonstrate that the presence of strong electro-withdrawing fluorine groups weakens the electronic cloud of adjacent C atoms,increasing OH^(-)attack on the C atom and improving the stability of piperidinium *** QBNp TP-QFC possesses a robust alkaline stability at 80℃(95.3%conductivity retention after testing in 2 M Na OH for 2160 h).An excellent peak power density of 1.44 W cm^(-2)and a remarkable durability at 80℃(4.5%voltage loss after 100 h)can be observed.

关键词： Anion exchange membranes Backbone structure Fluorinated side chain Alkaline stability

On the core entropy of Newton maps

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Science China Mathematics 2024年第1期67卷 77-128页

作者： Yan gao Department of Mathematics Shenzhen UniversityShenzhen 518060China

In this paper,we define the core entropy for postcritically-finite Newton maps and study its continuity within this *** show that the entropy function is not continuous in this family,which is different from the polyn... 详细信息

关键词： core entropy extended Newton graph critical marking polynomial Newton map

Segmental nature of the Red River fault revealed by seismic anisotropy and geological structures

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Science China Earth Sciences 2024年第8期67卷 2423-2443页

作者： Ying LI Yuan gao School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Key Laboratory of Earthquake Prediction Institute of Earthquake ForecastingChina Earthquake AdministrationBeijing 100036China

As the western boundary of the Sichuan-Yunnan block(SYB),the Red River fault(RRF)is a major fault that controls deep crustal movement and deformation in the southeast margin of the Tibetan Plateau and regulates middle-lower crustal *** data suggest that the RRF is segmented and exhibits distinct variations in seismicity,velocity structure and crustal deformation from north to *** anisotropy reveals a complex pattern of lateral spatial and vertical stratified distributions.(1)From the perspective of crustal stratification,in the upper crust,the fast wave polarization in the north segment of the RRF is complex and possibly influenced by the Sanjiang lateral collision zone and adjacent faults with varying *** fast wave polarization in the middle segment is in the NW-SE direction,indicating a localized area of closed down or locked up with consistent *** in the south segment,it presents a disordered pattern,signifying complex deep tectonics and stress conditions at the wedged intersection *** the middle-lower crust in the north and south segments of the RRF,the azimuthal anisotropy is strong and consistent with the spatial strike of the weak zone characterized by low-velocity and *** suggests a connection between the anisotropy and the material migration.(2)In the whole crustal scale,the fast wave directions in two sides of the RRF are consistent with the NW-SE tectonic *** indicates that the RRF,as a large fault potentially cutting through the whole crust,strongly controls the surrounding media.(3)In the lithospheric scale,the fast wave polarizations are oriented nearly E-W and independent of the fault strike,consistent with the low P-and S-wave velocity structures and positive radial anisotropy in the upper *** fast wave directions could be related to lithospheric olivine deformation and asthenospheric *** paper suggests a decoupling of deformation between the crust and the lithospheri

关键词： Red River fault Seismic anisotropy Geological structures Lithosphere Fault segmentation

Record-high efficiency perovskite LEDs achieved by accelerating radiative recombination

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Science China Materials 2024年第9期67卷 3039-3040页

作者： Feng gao Department of Physics Chemistry and BiologyLink?ping University

Light-emitting diodes(LEDs) have revolutionized the lighting and displays due to their superior energy efficiency. The increasing demand for more efficient and brighter thin-film LEDs in flat-panel displays and solid-state lighting applications has driven extensive research into perovskite materials, which show great promise for high brightness and efficiency.

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Effect of mesopore spatial distribution of HZSM-5 catalyst on zinc state and product distribution in 1-hexene aromatization

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Chinese Journal of Chemical Engineering 2024年第3期67卷 16-26页

作者： Chenhao Wei Di gao Guohao Zhang Liang Zhao Jinsen gao Chunming Xu The State Key Lab of Heavy Oil Processing China University of Petroleum(Beijing)Beijing 102249China SINOPEC Research Institute of Petroleum Processing Co. Ltd.Beijing 100083China

1-hexene aromatization is a promising technology to convert excess olefin in fluid catalytic cracking(FCC)gasoline to high-value benzene(B),toluene(T),and ***,the increasing market demand of xylene has put forward higher requirements for new generation of *** increasing xylene yield in 1-hexene aromatization,the effect of mesopore structure and spatial distribution on product distribution and Zn loading was *** with different mesopore spatial distribution were prepared by post-treatment of parent HZSM-5 zeolite,including NaOH treatment,tetra-propylammonium hydroxide(TPAOH)treatment,and *** was found the evenly distributed mesopore mainly prolongs the catalyst lifetime by enhancing diffusion properties but reduces the aromatics selectivity,as a result of damage of micropores close to the catalyst *** the selectivity of high-value xylene can be highly promoted when the mesopore is mainly distributed interior the ***,the state of loaded Zn was also affected by mesopores spatial *** the optimized catalyst,the xylene selectivity was enhanced by 12.4%compared with conventional Zn-loaded parent HZSM-5 catalyst at conversion over 99%.It was attributed to the synergy effect of mesopores spatial distribution and optimized acid *** work reveals the role of mesopores in different spatial positions of 1-hexene aromatization catalysts in the reaction process and the influence on metal distribution,as well as their synergistic effect two on the improvement of xylene selectivity,which can improve our understanding of catalyst pore structure and be helpful for the rational design of high-efficient catalyst.

关键词： 1-Hexene aromatization Alkali treatment Xylene selectivity Mesopores Zinc state