检索结果-南通市图书馆

An improved algorithm based on equivalent sound velocity profile method at large incident angle

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2024年第2期43卷 161-167页

作者： Qianqian Li Qian Tong Fanlin Yang Qi Li Zhihao Juan Yu Luo college of Geodesy and geomatics Shandong University of Science and TechnologyQingdao 266590China college of Underwater Acoustic engineering Harbin Engineering UniversityHarbin 150001China

With the development of ultra-wide coverage technology,multibeam echo-sounder(MBES)system has put forward higher requirements for localization accuracy and computational efficiency of ray tracing *** classical equivalent sound speed profile(ESSP)method replaces the measured sound velocity profile(SVP)with a simple constant gradient SVP,reducing the computational workload of beam ***,in deep-sea environment,the depth measurement error of this method rapidly increases from the central beam to the edge *** analyzing the positioning error of the ESSP method at edge beam,it is discovered that the positioning error increases monotonically with the incident angle,and the relationship between them could be expressed by polynomial ***,an error correction algorithm based on polynomial fitting is *** simulation experiment conducted on an inclined seafloor shows that the proposed algorithm exhibits comparable efficiency to the original ESSP method,while significantly improving bathymetry accuracy by nearly eight times in the edge beam.

关键词： equivalent sound speed profile ray tracing method large incident angle edge beam deep sea error correction multibeam echo-sounder system

Study on the evolution of solid–liquid–gas in multi-scale pore methane in tectonic coal

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical engineering 2024年第7期71卷 122-131页

作者： Junjie Cai Xijian Li Hao Sui Honggao Xie college of Resources and Environmental engineering Guizhou UniversityGuiyang 550025China mining college Guizhou UniversityGuiyang 550025China

The rich accumulation of methane(CH_(4))in tectonic coal layers poses a significant obstacle to the safe and efficient extraction of coal seams and coalbed *** coal samples from three geologically complex regions were selected,and the main results obtained by using a variety of research tools,such as physical tests,theoretical analyses,and numerical simulations,are as follows:22.4–62.5 nm is the joint segment of pore volume,and 26.7–100.7 nm is the joint segment of pore specific surface *** the dynamic gas production process of tectonic coal pore structure,the adsorption method of methane molecules is“solid–liquid adsorption is the mainstay,and solid–gas adsorption coexists”.Methane stored in micropores with a pore size smaller than the jointed range is defined as solid-state *** within the jointed range,which transition from micropore filling to surface adsorption,are defined as gaseous *** outside the jointed range,where solid–liquid adsorption occurs,are defined as liquid *** evolution of pore structure affects the methane adsorption mode,which provides basic theoretical guidance for the development of coal seam resources.

关键词： Tectonic coal Multiscale pore structure Methane adsorption Micropore filling Monolayer Molecular simulation

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

在线全文

学校读者我要写书评

暂无评论

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

Floor heave mechanism for gob-side entry retaining with concrete blocks and control method:A case study

在线全文

学校读者我要写书评

暂无评论

Underground Space 2024年第2期15卷 244-259页

作者： Jiong Wang Peng Liu Manchao He Guangyuan Yu Huanzhi Tian State Key Laboratory for Geomechanics and Deep Underground engineering China University of Mining and Technology(Beijing)Beijing 100083China School of Mechanics and Civil engineering China University of Mining and Technology(Beijing)Beijing 100083China college of mining engineering North China University of Science and TechnologyTangshan 063210China

The issue of significant floor heave deformation in gob-side entry retaining has long been a challenging problem in the context of longwall *** paper studies the floor heave failure mechanism and control method for gob-side entry retaining with concrete blocks in Guizhou Faer Coal Mine in *** on Rankine’s earth pressure theory,the effective shear stress equation for the plastic slip of roadway floor is *** deformation mechanism of floor heave in a retaining roadway with a block wall is revealed in this *** new comprehensive control method is proposed,encompassing roof pre-splitting blasting for pressure relief,reinforcing cables for roof control,double directions control bolts for concrete block,and pliability cushion yielding ***3D numerical calculation model is established,which shows that the new method can effectively reduce the average vertical stress peak value of the entity coal floor by 34.6%and significantly reduce the pressure source causing the roadway floor ***,a multi-parameter real-time online monitoring system for mine pressure was designed,and field tests were carried *** results show that the maximum value of roadway floor heave under the new method is 163 mm,reduced by 66.9%,and the roadway floor heave is effectively *** research findings offer a fresh perspective and new ideas for controlling floor heave in mining operations.

关键词： Gob-side entry retaining Floor heave mechanism Plastic slip Control methods Mine pressure monitoring

Adsorption behavior of CO2/H2S mixtures in calcite slit nanopores for CO2 storage:An insight from molecular perspective

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2444-2456页

作者： Cheng Qian Zhen-Hua Rui Yue-Liang Liu Kai Du Chen Liu Yang Zhao Xiao-Min Ma State Key Laboratory of Petroleum Resources and engineering China University of Petroleum college of Petroleum engineering China University of Petroleum college of Carbon Neutrality Future Technology China University of Petroleum college of Petroleum China University of Petroleum-Beijing at Karamay college of mining engineering Taiyuan University of Technology

It is acknowledged that injecting CO2into oil reservoirs and saline aquifers for storage is a practical and affordable method for *** CO2produced from industrial exhaust contains impurity gases such as H2S that might impact CO2sequestration due to competitive *** study makes a commendable effort to explore the adsorption behavior of CO2/H2S mixtures in calcite slit *** Canonical Monte Carlo（GCMC） simulation is employed to reveal the adsorption of CO2,H2S as well as their binary mixtures in calcite *** show that the increase in pressure and temperature can promote and inhibit the adsorption capacity of CO2and H2S in calcite nanopores,***2exhibits stronger adsorption on calcite surface than *** energy plays the dominating role in the adsorption *** energy accounts for 97.11% of the CO2-calcite interaction energy and 56.33% of the H2S-calcite interaction energy at 10 MPa and 323.15 *** presence of H2S inhibits the CO2adsorption in calcite nanopores due to competitive adsorption,and a higher mole fraction of H2S leads to less *** quantity of CO2adsorbed is lessened by approximately 33% when the mole fraction of H2S reaches ***2molecules preferentially occupy the regions near the po re wall and H2S molecules tend to reside at the center of nanopore even when the molar ratio of CO2is low,indicating that CO2has an adsorption priority on the calcite surface over *** addition,moisture can weaken the adsorption of both CO2and H2S,while CO2is more *** interestingly,we find that pure CO2is more suitable to be sequestrated in the shallower formations,i.e.,500-1500 m,whereas CO2with H2S impurity should be settled in the deeper reservoirs.

关键词： Adsorption behavior CO 2 /H 2 S binary mixtures Molecular perspective Calcite slit nanopores CO 2 sequestration

Ecological-Based mining:A Coal-Water-Thermal Collaborative Paradigm in Ecologically Fragile Areas in Western China

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

engineering 2024年第7期38卷 209-222页

作者： Xiaoxiu Liu Yifan Zeng Qiang Wu Shihao Meng Jiyue Liang Zhuping Hou National engineering Research Center of Coal Mine Water Hazard Controlling China University of Mining and TechnologyBeijing 100083China college of Geoscience and Surveying engineering China University of Mining and TechnologyBeijing 100083China University of mining and Technology(Beijing)Inner Mongolia Research Institute Ordos 017000China

A substantial reduction in groundwater level,exacerbated by coal mining activities,is intensifying water scarcity in western China’s ecologically fragile coal mining ***’s national strategic goal of achieving a carbon peak and carbon neutrality has made eco-friendly mining that prioritizes the protection and efficient use of water resources *** on the resource characteristics of mine water and heat hazards,an intensive coal-water-thermal collaborative co-mining paradigm for the duration of the mining process is *** integrated system for the production,supply,and storage of mining companion resources is achieved through technologies such as roof water inrush prevention and control,hydrothermal quality improvement,and deep-injection geological *** active preventive and control system achieved by adjusting the mining technology and a passive system centered on multiobjective drainage and grouting treatment are suggested,in accordance with the original geological characteristics and dynamic process of water *** implementing advanced multi-objective drainage,specifically designed to address the“skylight-type”water inrush mode in the Yulin mining area of Shaanxi Province,a substantial reduction of 50%in water drillings and inflow was achieved,leading to stabilized water conditions that effectively ensure subsequent safe coal *** integrated-energy complementary model that incorporates the clean production concept of heat utilization is also *** findings indicate a potential saving of 8419 t of standard coal by using water and air heat as an alternative heating source for the Xiaojihan coalmine,resulting in an impressive energy conservation of 50.2%and a notable 24.2%reduction in carbon *** ultra-deep sustained water injection of 100 m^(3)·h^(-1)in a single well would not rupture the formation or cause water leakage,and 7.87×10^(5)t of mine water could be effectively stored in the Liujiagou Formation,presenti

关键词： Dual carbon targets Coal-water-thermal co-mining Ecologically fragile areas Mine-water control Resource utilization

The dynamic characteristics of saturated remolded loess under cyclic load

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Earthquake Research Advances 2024年第2期4卷 27-35页

作者： Yuting Fu Yanbo Cao Jiaxu Kong Jia Zheng Jiaqi Mu Jie Wang Jianqi Zhuang college of Geological engineering and geomatics Key Laboratory of Western China Mineral Resources and Geological EngineeringChang’an UniversityXi’an710054China

Due to the joint development characteristic and macropore structure of loess,it is easy to cause structure collapse under earthquake or artificial *** study on the loess disaster effect and its mechanism under earthquake action is insufficient due to its ***,to study the deformation and mechanical properties more accurately,the dynamic characteristics of saturated remolded loess under cyclic dynamic load were tested using a GDS dynamic triaxial instrument in this *** test results show that strain and pore water pressure increase gradually at different rates with the development of vibration,and there is an obvious inflection point in the time-history curve of *** the number of vibrations(N)exceeds this point,the strain increases rapidly,and pore water pressure tends to be *** the action of large amplitude and low-frequency dynamic load,the strain and pore water pressure increase rapidly with fewer vibrations and the deviator stress(q)decreases rapidly,while the sample achieves damage faster with the increase of *** the application of a dynamic load,the effective stress(p)gradually decreases and its rate of change slows ***,when the saturated remolded loess is subjected to a constant-amplitude dynamic load,the combination of large amplitude and low frequency leads to the failure of the sample in the shortest time.

关键词： Loess Pore water pressure Strain Frequency Amplitude Quake(vibration)

Restraint effect of partition wall on the tunnel floor heave in layered rock mass

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第7期21卷 2462-2479页

作者： YANG Yunyun HUANG Da ZHONG Zhu LIU Yang PENG Jianbing School of Civil and Transportation engineering Hebei University of TechnologyTianjin 300401China college of Geology engineering and geomatics Chang’an UniversityXi’an 710054China college of Civil engineering&Architecture China Three Gorges UniversityYichang 443002China.

The presence of horizontal layered rocks in tunnel engineering significantly impacts the stability and strength of the surrounding rock mass,leading to floor heave in the *** study focused on preparing layered specimens of rock-like material with varying thickness to investigate the failure behaviors of tunnel *** results indicate that thin-layered rock mass exhibits weak interlayer bonding,causing rock layers near the surface to buckle and break upwards when subjected to horizontal *** an increase in the layer thickness,a transition in failure mode occurs from upward buckling to shear failure along the plane,leading to a noticeable reduction in floor heave *** primary cause of significant deformation in floor heave is upward buckling *** address this issue,the study proposes the installation of a partition wall in the middle of the floor to mitigate heave deformation of the rock *** results demonstrate that the partition wall has a considerable stabilizing effect on the floor,reducing the zone of buckling failure and minimizing floor heave *** is crucial for the partition wall to be sufficiently high to prevent buckling failure and ensure *** simulation calculations on an engineering example,it is confirmed that implementing a partition wall can effectively reduce floor heave and enhance the stability of tunnel floor.

关键词： Layered rock Floor heave Horizontal compression test Failure behavior Partition wall

Delineating homogeneous domains of fractured rocks using topological manifolds and deep learning

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical engineering 2024年第8期16卷 2996-3013页

作者： Yongqiang Liu Jianping Chen Fujun Zhou Jiewei Zhan Wanglai Xu Jianhua Yan college of Construction engineering Jilin UniversityChangchun130026China China Railway First Survey and Design Institute Group Co. Ltd.Xi’an710043China college of Geological engineering and geomatics Chang’an UniversityXi’an710054China

Determining homogeneous domains statistically is helpful for engineering geological modeling and rock mass stability *** this text,a technique that can integrate lithology,geotechnical and structural information is proposed to delineate homogeneous *** technique is then applied to a high and steep slope along a ***,geological and geotechnical domains were described based on lithology,faults,and shear ***,topological manifolds were used to eliminate the incompatibility between orientations and other parameters(*** length and roughness)so that the data concerning various properties of each discontinuity can be matched and characterized in the same Euclidean ***,the influence of implicit combined effect in between parameter sequences on the homogeneous domains could be *** learning technique was employed to quantify abstract features of the characterization images of discontinuity properties,and to assess the similarity of rock mass *** results show that the technique can effectively distinguish structural variations and outperform conventional *** can handle multisource engineering geological information and multiple discontinuity *** technique can also minimize the interference of human factors and delineate homogeneous domains based on orientations or multi-parameter with arbitrary distributions to satisfy different engineering requirements.

关键词： Homogeneous domain Geological domain Geotechnical domain Structural domain Topological manifold Deep learning