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Residual subsidence time series model in mountain area caused by underground mining based on GNSS online monitoring

International Journal of Coal Science & Technology 2024年第2期11卷 173-186页

作者： Xugang Lian Lifan Shi Weiyu Kong Yu Han Haodi Fan school of mining engineering Taiyuan University of TechnologyTaiyuanChina

The residual subsidence caused by underground mining in mountain area has a long subsidence duration time and great potential harm,which seriously threatens the safety of people's production and life in the mining ***,it is necessary to use appropriate monitoring methods and mathematical models to effectively monitor and predict the residual subsidence caused by underground *** with traditional level survey and InSAR(Interferometric Synthetic Aperture Radar)technology,GNSS(Global Navigation Satellite System)online monitoring technology has the advantages of long-term monitoring,high precision and more flexible monitoring *** empirical equation method of residual subsidence in mining subsidence is effectively combined with the rock creep equation,which can not only describe the residual subsidence process from the mechanism,but also predict the residual ***,based on GNSS online monitoring technology,combined with the mining subsidence model of mountain area and adding the correlation coefficient of the compaction degree of caving broken rock and the Kelvin model of rock mechanics,this paper constructs the residual subsidence time series model of arbitrary point on the ground in mountain *** the example,the predicted results of the model in the inversion parameter phase and the dynamic prediction phase are compared with the measured data *** results show that the model can carry out effective numerical calculation according to the GNSS monitoring data of any point on the ground,and the model prediction effect is good,which provides a new method for the prediction of residual subsidence in mountain mining.

关键词： Underground mining in mountain area Residual subsidence GNSS online monitoring Mathematical model Subsidence prediction

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Pore-pressure and stress-coupled creep behavior in deep coal:Insights from real-time NMR analysis

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International Journal of mining Science and Technology 2024年第1期34卷 77-90页

作者： Wenhao Jia Hongwei Zhou Senlin Xie Yimeng Wang Xinfeng Hu Lei Zhang school of Mechanics and Civil engineering China University of Mining and Technology-BeijingBeijing 100083China school of Energy and mining engineering China University of Mining and Technology-BeijingBeijing 100083China State Key Laboratory of Coal Resources and Safe mining China University of Mining and Technology-BeijingBeijing 100083China College of Safety and Emergency Management engineering Taiyuan University of TechnologyTaiyuan 030024China

Understanding the variations in microscopic pore-fracture structures(MPFS) during coal creep under pore pressure and stress coupling is crucial for coal mining and effective gas treatment. In this manuscript, a triaxial creep test on deep coal at various pore pressures using a test system that combines in-situ mechanical loading with real-time nuclear magnetic resonance(NMR) detection was ***-scale quantitative characterization, online real-time detection, and visualization of MPFS during coal creep influenced by pore pressure and stress coupling were performed using NMR and NMR imaging(NMRI) techniques. The results revealed that seepage pores and microfractures(SPM) undergo the most significant changes during coal creep, with creep failure gradually expanding from dense primary pore fractures. Pore pressure presence promotes MPFS development primarily by inhibiting SPM compression and encouraging adsorption pores(AP) to evolve into SPM. Coal enters the accelerated creep stage earlier at lower stress levels, resulting in more pronounced creep deformation. The connection between the micro and macro values was established, demonstrating that increased porosity at different pore pressures leads to a negative exponential decay of the viscosity coefficient. The Newton dashpot in the ideal viscoplastic body and the Burgers model was improved using NMR experimental results, and a creep model that considers pore pressure and stress coupling using variable-order fractional operators was developed. The model’s reasonableness was confirmed using creep experimental data. The damagestate adjustment factors ω and β were identified through a parameter sensitivity analysis to characterize the effect of pore pressure and stress coupling on the creep damage characteristics(size and degree of difficulty) of coal.

关键词： Real-time monitoring Pore pressure-stress coupling Microscopic pore-fracture structure Variable-order fractional creep model Deep coal

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Toroidal dipole response in rectangular waveguide:used to generate vector beams and vector vortex beams

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Chinese Optics Letters 2024年第1期22卷 90-97页

作者：罗灏陈聪高鹏冯越任紫燕乔昱嘉刘海 school of Information and Control engineering China University of Mining and TechnologyXuzhou 221116China

Toroidal multipole is a special current distribution that has many different characteristics from electric multipole and magnetic multipole *** of its special properties,the toroidal dipole is a research hotspot in the field of metamaterials and ***,the low scattering of the toroidal dipole moment makes its excitation a challenging *** present,there are relatively few studies on its specific engineering *** this paper,by slotting in the rectangular cavity,the excitation of an equivalent toroidal dipole is successfully achieved over a wide frequency range of 53-58 *** indicate that under the action of the toroidal dipole,the TE_(10)mode electromagnetic waves transmitted in the rectangular waveguide are converted into vector beams and are radiated *** adjusting the spatial distribution of the magnetic dipoles in the toroidal dipoles yields results that indicate that the resonance mode in the slot is still dominated by the magnetic toroidal dipole moment,and the electromagnetic waves radiating outward are vortex beams carrying vector *** scattered energy of each dipole moment inside the antenna is *** calculation verifies that the mass of the vector beam and vector vortex beam is closely related to the toroidal dipole supported by this *** proposed structure can be applied to explorations in vortex filtering,in photon entanglement,and in the photonic spin Hall effect.

关键词： toroidal dipole vector beams vector vortex beams

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The influence of inter-band rock on rib spalling in longwall panel with large mining height

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International Journal of mining Science and Technology 2024年第4期34卷 427-442页

作者： Jiachen Wang Meng Li Zhaohui Wang Zheng Li Han Zhang Shixiong Song school of Energy and mining engineering China University of Mining and Technology-BeijingBeijing 100083China Coal Industry engineering Research Center of Top-coal Caving mining Beijing 100083China Faculty of engineering Hokkaido UniversitySapporo 060-8628Japan

In order to improve rib stability,failure criteria and instability mode of a thick coal seam with inter-band rock layer are analysed in this study.A three-dimensional mechanical model is established for the rib by considering the rock layer.A safety factor is defined foy the rib,and it is observed that the safety factor exhibits a positive correlation with the thickness and strength of the inter-band rock.A calculation method for determining critical parameters of the rock layer is presented to ensure the rib *** is revealed that incomplete propagation of the fracture at the hard rock constitutes a fundamental prerequisite for ensuring the rib *** influence of the position of the inter-band rock in the coal seam on failure mechanism of the rib was thoroughly investigated by developing a series of physical models for the rib at the face *** best position for the inter-band rock in the coal seam is at a height of 1.5 m away from the roof line,which tends to provide a good stability state for the *** different inter-band rock positions,two ways of controlling rib by increasing supports stiffness and flexible grouting reinforcement are proposed.

关键词： Rib spalling Inter-band rock Large mining height Limit analysis Physical model experiment Numerical simulation

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Transient synthesis of carbon-supported high-entropy alloy sulfide nanoparticles via flash Joule heating for efficient electrocatalytic hydrogen evolution

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Nano Research 2024年第4期17卷 3379-3389页

作者： Yuntian Liao Rongtao Zhu Wenjun Zhang Haiyang Zhu Yang Sun Jiale Chen Zhenhua Dong Ronghuan Lv school of Chemical engineering and Technology China University of Mining and TechnologyXuzhou 221116China

High entropy alloys(HEA)are frequently employed as catalysts in electrocatalytic hydrogen ***,the traditional high entropy alloy synthesis methods are time-consuming,energy-intensive,and environmentally polluting,which limits their application in the hydrogen evolution reaction(HER).This study leveraged the capabilities of flash Joule heating(FJH)to synthesize carbon-supported high-entropy alloy sulfide nanoparticles(CC-S-HEA)on carbon cloth(CC)with good self-standing properties within 300 *** carbon thermal shock generated by the Joule heating could pyrolyze the sulfur source into gas,resulting in numerous pore structures and defects on CC,forming an S-doped carbon substrate(CC-S).Then the S atoms were used to stably anchor the metal atoms on CC-S to form high-density uniformly dispersed HEA *** electrochemical test results demonstrated that CC-S-HEA prepared at 60 V flash voltage had HER performance comparable to Pt/*** density functional theory(DFT)calculation indicated that the S atoms on CC-S accelerated the electron transfer between the carbon substrate and HEA ***,the unique electronic structure of CC-S-HEA was beneficial to H*adsorption and promoted catalytic *** simplicity and versatility of FJH synthesis are of great significance for optimizing the synthesis of HEA and improving the quality of HEA products,which provides a broad application prospect for the synthesis of nanocatalysts with efficient HER performance.

关键词： high entropy alloy flash Joule heating carbon thermal shock hydrogen evolution reaction density functional theory

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Energy Absorption by 3D-Printed Mesh Structures with a Negative Poisson’s Ratio

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 205-212页

作者： Wenyu Li Weiming Yang Mingze Li Xiang Zhang Ping Zhang Yucheng Zhao Peijian Chen Haishun Liu school of Mechanics and Civil engineering China University of Mining and TechnologyXuzhou221116China school of Materials Sciences and Physics China University of Mining and TechnologyXuzhou221116China

A negative Poisson's ratio(NPR)structure represents optimal impact-resistance with applications in various fields,including the crash box in vehicles,which absorbs impact kinetic *** crash box is designed to deform in response to impact,increasing local structural density,which enhances impact resistance *** studies have only focused on the NPR effect in the plane dimension at low-speed *** studies have considered high-speed impact loads on three-dimensional NPR *** have developed two types of AlSi10Mg alloy energy-absorbing structures with NPR using three-dimensional printing technology,and have compared our systems with a conventional hexagonal mesh *** testing involved split-Hopkinson pressure bar measurements,which showed good agreement with dynamic numerical *** subjected to an impact load,the NPR structure exhibited better impact resistance and energy absorption compared with the positive Poisson's ratio *** proposed dual-layer hexagonal structure ensures an NPR effect while exhibiting higher strength and improved stability relative to the conventional concave hexagon structure.

关键词： Negative Poisson’s ratio Energy absorption 3D printing Split-Hopkinson pressure bar Numerical simulation

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Nonlinear empirical failure criterion for rocks under triaxial compression

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International Journal of mining Science and Technology 2024年第3期34卷 351-369页

作者： Hongtao Liu Zhou Han Zijun Han Zihan Chen Qinyu Liu Hongkai Zhang Rongguang Zhang Linfeng Guo school of Energy&mining engineering China University of Mining and Technology-BeijingBeijing 100083China China National Coal Association Beijing 100010China

Based on existing triaxial compression experimental data,a new empirical failure criterion with wide applicability was proposed considering hydrostatic pressure,second stress invariance,and maximum shear *** fitting evaluation indicators were used to verify the consistency of the new failure criterion,and the differences with the other 6 failure criteria were *** characteristics of the new failure criteria in the principal stress space were finally *** results indicate that(1)the new failure criterion exhibits strong predictive ability for triaxial experiments and has good applicability for both intact and jointed rocks;(2)the influence of hydrostatic pressure on the failure surface exhibits a non-linear trend,and different hydrostatic pressure also exhibits different distribution patterns on the deviatoric stress plane,with a distribution characteristic pattern of hexagonal snowflake-regular *** maximum shear stress has a torsional effect on the new criterion,in the three-dimensional failure *** parameters a and b of the rock have an impact on the failure surface morphology of the new criterion function on the offset surface.

关键词： surface. criterion hydrostatic

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Quasi-static and dynamic compressive behaviour of additively manufactured Menger fractal cube structures

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Defence Technology（防务技术） 2024年第7期37卷 39-49页

作者： Damith Mohotti Dakshitha Weerasinghe Madhusha Bogahawaththa Hongxu Wang Kasun Wijesooriya Paul JHazell school of engineering and Technology UNSWCanberraACT2600Australia school of Civil Mining and Environmental EngineeringFaculty of Engineering and Information SciencesUniversity of WollongongWollongongNSWAustralia

This paper presents the first-ever investigation of Menger fractal cubes'quasi-static compression and impact *** cubes with different void ratios were 3D printed using polylactic acid(PLA)with dimensions of 40 mm×40 mm×40 *** different orders of Menger cubes with different void ratios were considered,namely M1 with a void ratio of 0.26,M2 with a void ratio of 0.45,and M3with a void ratio of ***-static Compression tests were conducted using a universal testing machine,while the drop hammer was used to observe the behaviour under impact *** fracture mechanism,energy efficiency and force-time histories were *** the structured nature of the void formation and predictability of the failure modes,the Menger geometry showed some promise compared to other alternatives,such as foams and *** the increasing void ratio,the Menger geometries show force-displacement behaviour similar to hyper-elastic materials such as rubber and *** third-order Menger cubes showed the highest energy absorption efficiency compared to the other two geometries in this *** findings of the present work reveal the possibility of using additively manufactured Menger geometries as an energy-efficient system capable of reducing the transmitting force in applications such as crash barriers.

关键词： Additive manufacturing Fractal geometries Menger cube Energy absorption Quasi-static

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Evolution mechanism and quantitative characterization of initial micro-cracks in marble under triaxial compression

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2024年第7期25卷 586-595页

作者： Zhiliang WANG Songyu LI Jianguo WANG Ao LI Weixiang WANG Chenchen FENG Jingjing FU school of Civil engineering Hefei University of TechnologyHefei230009China school of Mechanics and Civil engineering China University of Mining and TechnologyXuzhou221116China

The initial micro-cracks affect the evolution characteristics of macroscopic deformation and failure of rock but are often ignored in theoretical calculation,numerical simulation,and mechanical *** this study,we propose a quantitative analysis model to investigate the effects of initial micro-cracks on the evolution of marble deformation and *** relationship between the micro-crack propagation and the marble failure characteristics was comprehensively studied by combining theoretical analysis with a micro-computed tomography(micro-CT)scanning *** found that with the increase of confining pressure,the matrix elastic modulus of the marble first increased and then tended to be stable,while the micro-cracks increased *** sensitivity ranges of the marble sample matrix elastic modulus and micro-cracks to confining pressure were 0–30 MPa and 30–50 MPa,*** porosity and Poisson’s ratio decreased *** increasing proportion of internal micro-cracks led to an increase in the sample *** samples presented mainly shear failure under triaxial compression,and the failure angle decreased linearly with the increase of confining *** convergence direction of cracks decreased *** quantitative analysis model could accurately portray the relationship between the overall macroscopic deformation and the deviatoric stress of the samples at the compaction and the linear elastic stages,thus deepening the understanding of the stress–strain behavior of rocks.

关键词： Marble Initial micro-cracks Triaxial compression Constitutive relationship Crack evolution

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Preparation of a high-performance synthetic pitch from aromatic hydrocarbons containing N/Cl

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新型炭材料（中英文） 2024年第4期39卷 655-667页

作者： ZHANG Yu-kun LIN Xiong-chao GAO Hong-feng XI Wen-shuai WANG Cai-hong WANG Yong-gang school of Chemical&Environmental engineering China University of Mining and Technology(Beijing)Beijing 100083China

The preparation of a synthetic pitch from aromatic monomers could easily regulate structure orientation at the molecu-lar level,which would be useful in *** isotropic synthetic pitch was prepared by a chlorine-and/or nitrogen-induced sub-stitution polymerization reaction method using aromatic hydrocarbon precursors containing Cl and N,which for this study were chloromethyl naphthalene and *** method was verified by investigating the structural changes under different synthesis conditions,and the synthesis mechanism induced by aromatics containing Cl was also *** result shows that the pyridinic N in quinoline contains a lone pair of electrons,and is an effective active site to induce the polymerization reaction by coupling with aromatic hydrocarbons containing *** reaction between such free radicals causes strong homopolymerization and oligomeriza-tion.A higher reaction temperature and longer reaction time significantly increased the degree of polymerization and thus increased the softening point of the pitch.A linear molecular structure was formed by the Cl substitution reaction,which produced a highly spinnable pitch with a softening point of 258.6℃,and carbon fibers with a tensile strength of 1163.82 MPa were *** study provides a relatively simple and safe method for the preparation of high-quality spinnable pitch.

关键词： Quinoline 1-Chloromethyl-naphthalene Synthetic pitch Spinnability Carbon fiber

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