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Dynamic monitoring of soil bulk density and infiltration rate during coal mining in sandy land with different vegetation

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International Journal of Coal Science & Technology 2014年第2期1卷 198-206页

作者： Yinli Bi Hui Zou Chenwei Zhu college of Geoscience and surveying Engineering China University of Mining and Technology(Beijing)Beijing 100083China

To investigate the effects of coal mining on soil physical properties,sandy lands with three major vegetation types(Salix psammophila,Populus simonii,and Artemisia ordosica)were investigated by the ring knife method and double-ring ***,variations in soil bulk density and water infiltration rate and the influences of coal mining and vegetation type on the properties during different subsidence stages were studied at the Shendong Bulianta *** results showed that,in the period before mining,soil bulk density occurred in the order ***>***>***,with a negative correlation between the initial infiltration rate and steady infiltration rate being *** the period during mining and 3 months after mining,there were no significant differences in soil bulk density and water infiltration rate among vegetation *** 1 year after mining,the soil bulk density occurred in the order ***>***>***,having a negative correlation with the steady infiltration *** water infiltration depths of the ***,*** and *** were 50,60,and 30 cm,*** infiltration characters were simulated by the Kostiakov equations,and the simulated and experimental results were *** regression revealed that vegetation types and soil bulk density had significant effects on soil initial infiltration rate during the four study periods,and the infiltration rate of the period 1 year after mining was mainly influenced by the soil bulk density of the period before *** results indicated that vegetation types had significant effects on soil bulk density,and that the tree-shrub-grass mode was better than one single plantation for water conversation and vegetation recovery in sandy land subjected to mining.

关键词： Soil bulk density Soil infiltration rate Sandy land Vegetation type

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The effects of factor generalization scales on the reproduction of dynamic urban growth

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Geo-Spatial Information Science 2022年第3期25卷 457-475页

作者： Yongjiu Feng Peiqi Wu Xiaohua Tong Pengshuo Li Rong Wang Yilun Zhou Jiafeng Wang Jinyu Zhao college of surveying&Geo-Informatics Tongji UniversityShanghaiChina The Shanghai Key Laboratory of Space Mapping and Remote Sensing for Planetary Exploration Tongji UniversityShanghaiChina

The production and selection of driving factors are essential to building a strong Cellular Automata(CA)model of dynamic urban growth simulation.A critical issue that should be addressed is how the spatial representation and the generalization scale of driving factors affect the CA modeling and the simulation *** is challenging to evaluate the effectiveness of the selected driving factors because they have no true *** explore the impacts of the generalization scales,we produced nine sets of driving factors at nine scales to calibrate the CA models based on the Particle Swarm Optimization(CAPSO)and applied them to simulate urban growth of Suzhou during *** results show that the driving factors at a smaller scale have much better performance in explaining urban growth simulations as inferred by the Explained Residual Deviance(ERD)of the Generalized Additive Models(GAMs).Specifically,the ERD declined from 51.9%to 45.9%as the factor scale became larger during 2000-2020,but there was a peak value(52.2%)at *** all simulations during 2000-2020,the CAPSO models with larger-scale factors have slightly lower overall accuracy and Figure-of-Merit(FOM),which respectively decreased by 3.1%and 4.4%as compared to the CA models with scale-free *** concluded that the driving factors at a smaller scale(200~400 m for point-like facilities and 7~14 m for line-like facilities)can build more accurate CA models to simulate urban growth patterns,and the optimal scale for factors can be identified using the *** study contributes to the methods of evaluating the effectiveness of driving factor production and reveals the impacts of spatial representation of factors on the CA modeling and simulation considering the factor generalization scales.

关键词： Cellular automata urban growth driving factors scale effects generalized additive model

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Geochemistry of arsenic and selenium in a Ge-poor coal from the Wulantuga coal-hosted Ge ore deposit,Inner Mongolia,North China

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International Journal of Coal Science & Technology 2014年第4期1卷 383-389页

作者： Panpan Xie Qingqian Li Jingjing Liu Hongjian Song Jianpeng Wei college of Geoscience and surveying Engineering China University of Mining and Technology(Beijing)Beijing 100083China

This paper reports new data for arsenic(As)and selenium(Se)in a total of twelve bench samples of Ge-rich and Ge-poor coals in the No.6 coal seam from the Wulantuga ore deposit,Inner Mongolia,Northeastern *** Gepoor coals are characterized by low-ash(with a weighted average ash yield 10.59%).The coal samples were digested using an UltraClave microwave high pressure reactor(milestone)and trace elements were detected by inductively coupled plasma mass spectrometry—collision/reaction cell technology,a reliable method for As and Se determination in coal *** contents of As and Se in the Ge-poor(with a weighted average content of 9.14 and 0.30 lg/g,respectively)and Ge-rich coal samples in the present study(varies from 16.88 to 17,776 lg/g and from 0.26 to 14.39 lg/g,respectively)are in a sharp *** As in the Ge-poor coals is of both organic-and pyrite-associations,and its enrichment is attributed to the sediment source,and to a lesser extent,to hydrothermal *** is predominantly connected with organic matter in the Wulantuga Ge-poor coals.

关键词： Arsenic Selenium Wulantuga Ge ore deposit

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The precise multimode GNSS positioning for UAV and its application in large scale photogrammetry

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Geo-Spatial Information Science 2016年第3期19卷 188-194页

作者： Hongxing Sun Leilei Li Xuewen Ding Bingxuan Guo State Key Laboratory of Information Engineering in surveying Mapping and Remote SensingWuhan UniversityWuhanChina college of Aerospace Engineering Chongqing UniversityChongqingChina

In this paper,we use multimode GNSS instead of single GPS constellation to resolve the three exterior line elements of each *** principles of differential GNSS positioning and GNSSsupported aerial triangulation(AT)are presented and an implementation case is *** multi-constellation system,the number of visible satellites is significantly increased and the geometry distribution of the satellites is well *** positioning accuracy and robustness are therefore getting better compared to GPS *** results show that differential GNSS has remarkable increment on the integer rate of ambiguity solution when GPS has few number and low elevation angle of *** combined AT adjustment of GNSS resolution and 10 ground control points(GCPs)achieve the horizontal accuracy of±18 cm and vertical accuracy of±23 cm for the check points,which are comparable with traditional bundle adjustment with dense GCPs and better than GPS-supported *** achieved accuracy also satisfies the requirement for 1:500 topographic maps with the bonus of 84%GCPs *** conclusion,GNSS-supported AT is of feasibility and superiority for large scale Unmanned Aerial Vehicle-based photogrammetry.

关键词： Multi-constellation differential GNSS UAV photogrammetry GNSS-supported aerial triangulation

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Influence of geological factors on coal permeability in the Sihe coal mine

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International Journal of Coal Science & Technology 2022年第1期9卷 58-70页

作者： Guangui Zou Qianhua Zhang Suping Peng Jiasheng She Deliang Teng Chaochao Jin Yuyan Che State Key Laboratory of Coal Resources and Safe Mining BeijingChina college of Geoscience and surveying Engineering China University of Mining&TechnologyBeijingChina

Permeability of coal reservoirs influence the extraction of coal gas from coal *** coal samples were collected at an anticline and a syncline of the No.3 coal seam in the Sihe coal ***,permeability,pore size,vitrinite reflectance,and liquid nitrogen adsorption of the samples were *** curvatures at the sample locations,and the distance between the sampling locations and the nearest faults were calculated based on seismic *** influences of the evaluated parameters on permeability were *** factors that influence permeability of the No.3 coal seam were extracted using principal component analysis(PCA).Based on the porosity–permeability model derived from the Archie formula and classic Kozeny–Carman equation,we deduced that the permeability of coal increased with an increase in *** an increase in average vitrinite reflectance,permeability decreases first and then *** results showed that coal permeability was regulated by three key components representing three *** first component included pore size,depth,and pore complexity accounting for 52.59%of the variability indicating that it was the most important in controlling *** second component included specific surface area,structural curvature,and porosity,and the third component comprised of specific surface area,porosity,and average vitrinite ***,pore diameter and complexity had significant effects on coal *** results show that researchers and stakeholders must consider the interactions among multiple factors rather than single factors to understand the influences on permeability to facilitate efficient utilization of coalbed methane resources.

关键词： Coal mine Permeability Geological factors Principal component analysis

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A Transgressive Depositional Setting for the Paleogene Shahejie Formation in the Qikou Depression, Eastern China: Inferences from the REE Geochemistry of Carbonates

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Journal of Earth Science 2018年第2期29卷 326-341页

作者： Yang Yang Fuhong Gao Changwei Chen Xiugang Pu School of Prospecting & surveying Engineering Changchun Institute of Technology college of Earth Sciences Jilin University Research Institute of Exploration and Development Dagang Oilfield Company CNPC

Rare earth element （REE） and Y concentrations, and S7Sr/S6Sr ratios were analyzed in 33 carbonate samples from the Paleogene Shahejie Formation in the Qikou depression, eastern China, with the goal of determining depositional environments and post-depositional conditions of carbonates in the region. The REE and Y concentrations were normalized to the post-Archean Australian shale （PAAS） standard. The La＊pAAs/Yb＊pAAS ratios of 0.35-1.52, where ＊PAAS indicates values for the PAAS standard, show fight REE enrichment and heavy REE depletion in most samples. Values of La＊PAAS （0.775-1.284） and Ce＊PAAS （0.822-L224）, coupled with a relatively flat REE distribution, indicate that the Shahejie car- bonates were deposited in lacustrine environments. Values of Y anomalies （1.009-1.527） and Y/Ho ratios （28.43-45.00） in the Shahejie Formation are greater than those of lacustrine carbonates and closer to those of marine carbonates, indicating that diagenetic fluids were probably influenced by seawater. In the car- bonates from Well Kou-42, Eu anomalies （1.171-1.604）, ^87Sr/^86Sr ratios （0.708 001-0.710 893）, and high homogenization temperatures （104-151 ℃） suggest that the carbonates were affected by hydrothermal fluids. The REEs and Sr isotope ratios show that the carbonates from the Shahejie Formation in the Qikou depression were deposited in lacustrine environments, and were influenced by seawater and hydrothermal fluids.

关键词： Paleogene carbonate REE Qikou depression.

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Assessment of tomographic window and sampling rate efects on GNSS water vapor tomography

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Satellite Navigation 2023年第1期4卷 155-166,I0005页

作者： Fei Yang Yilin Sun Xiaolin Meng Jiming Guo Xu Gong college of Geoscience and surveying Engineering China University of Mining and Technology-BeijingBeijing 100083China college of Architecture and Civil Engineering Beijing University of TechnologyBeijing 100124China School of Geodesy and Geomatics Wuhan UniversityWuhan 430079China

The ground-based Global Navigation Satellite System(GNSS)water vapor tomography is increasingly important in GNSS *** the multi-GNSS and more ground-based GNSS sites can be incorporated into the regional water vapor tomographic model,determining the tomographic window and sampling rate is crucial for the modelling of the water vapor *** two factors afect not only the number of available signal rays from the satellites,but also the number of tomographic voxels crossed by the signal *** study uses Hong Kong as the research area to explore the impact of 12 schemes with diferent tomographic window and sampling rate on the three water vapor tomography methods,including Least squares,Kalman fltering,and Multiplicative Algebraic Reconstruction Technique(MART).Numerical results show that the tomographic results with the three methods get better as the width of the tomographic window decreases and the sampling rate increases in these 12 schemes,and it is found that the Least squares method is most afected by the two factors,followed by Kalman fltering and MART *** is recommended to set a tomographic window width of 10 min and a sampling rate of 300 s in a GNSS water vapor tomographic experiment with dense GNSS site like Hong Kong.

关键词： GNSS meteorology Water vapor Tomography

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Using geophysical logs to identify Milankovitch cycles and to calculate net primary productivity(NPP) of the Late Permian coals,western Guizhou,China

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Journal of Palaeogeography 2019年第1期8卷 31-42页

作者： Zhi-Ming Yan Long-Yi Shao David Large Hao Wang Baruch Spiro college of Geoscience and surveying Engineering China University of Mining and Technology (Beijing) Faculty of Engineering University of Nottingham Department of Earth Sciences Natural History MuseumLondon

Milankovitch periodicities of 123 kyr(eccentricity), 35.6 kyr(obliquity), and 21.2 kyr(precession) were identified in geophysical logs of three Late Permian coals: 17#, 18#, and 17 + 18#, from the Songhe mining area in western Guizhou Province. Based on the astronomic temporal framework, the periods of deposition of the 17#(5.6 m), 18#(6.4 m), and 17 + 18#(5.4 m) coals were constrained to 140.8–119.8 kyr, 160–136.2 kyr, and 135–114.9 kyr,respectively. The overall depositional period of the 18# coal of 160–136.2 kyr was further subdivided using the wavelet analysis method, into short and precise periods corresponding to the Milankovitch periodicities. It includes one eccentricity periodicity(123 kyr), three obliquity periodicities(35.6 kyr), and five precession periodicities(21.2 kyr). Different thicknesses of the subdivided coal sections, equivalent to the same time span of deposition, indicate different rates of coal deposition, i.e., thicker sections imply higher rates while the thinner sections represent lower rates. The combination of the measured average carbon concentration with the density of the coals gave rise to long-term average values of carbon accumulation rates for the Late Permian coals, in the range of 42.4–50.6 g?C?m^(-2)?a^(-1). This range corresponds to the long-term average carbon accumulation rates for the initial peat in the range of 60.6–72.3 g?C?m^(-2)?a^(-1). Based on the known quantitative relation between net primary productivity(NPP)values and long-term average carbon accumulation rates for the Holocene tropical peatlands, the range of NPP values for the Late Permian tropical peatlands was estimated as 242.4–433.8 g?C?m^(-2)?a^(-1).A comparison of existing information about peatland NPP levels of various ages and latitudes indicated that when conditions of high rain and high humidity prevail in the palaeo-peatland at given latitude, the NPP rates will vary with changes in atmospheric concentration of CO_2 and O_2. This relationship may le

关键词： Milankovitch cycle Coal deposition Peatland Long-term average carbon accumulation rate Net primary productivity Late Permian Guizhou Province

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Desorption hysteresis of coalbed methane and its controlling factors: a brief review

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Frontiers of Earth Science 2021年第2期15卷 224-236页

作者： Weikai XU Junhui LI Xiang WU Du LIU Zhuangsen WANG college of Geoscience and surveying Engineering China University of Mining and TechnologyBeijing 100083China China Coalbed Methane Co.Ltd Beijing 100011China

Most coal reservoirs show high gas content with relatively low desorption efficiency,which restricts the efficiency of coalbed methane(CBM)extraction and single-well *** review highlights the desorption hysteresis mechanism and its controlling factors as well as methods and models to reveal desorption hysteresis and potential *** adsorption and desorption can be recorded by both gravimetric and volumetric *** different adsorption models are used,desorption is generally considered with the Langmuir *** hysteresis is influenced by the petrophysical composition,thermal maturity,pore structure distribution of the coal,reservoir temperature,and moisture and water *** for calculating desorption hysteresis include the area index,hysteresis index and introduction of a hysteresis factor and a hysteresis *** dynamics simulations of methane desorption are mainly based on theories of kinetics,thermodynamics,and potential *** interaction forces operating among coal,water,and methane molecules can be calculated from microscopic intermolecular forces(van der Waals forces).The desorption hysteresis mechanism and desorption process still lack quantitative probe methodologies,and future research should focus on coal wettability under the constraints of liquid content,potential energy adjustment mechanism,and quantitative analysis of methane desorption *** research is expected to reveal the desorption kinetics of methane through the use of the solid–liquid–gas three-phase coupling theory associated with the quantitative analysis of methane desorption hysteresis,thereby enhancing the recovery rate and efficiency of CBM wells.

关键词： desorption hysteresis diffusion process kinetics multiphase coupling coalbed methane production

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Geochemistry and origins of hydrogen-containing natural gases in deep Songliao Basin,China:Insights from continental scientific drilling

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Petroleum Science 2024年第2期21卷 741-751页

作者： Shuang-Biao Han Chao-Han Xiang Xin Du Lin-Feng Xie Jie Huang Cheng-Shan Wang college of Geoscience and surveying Engineering China University of Mining and TechnologyBeijing100083China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesBeijing100083China

The different reservoirs in deep Songliao Basin have non-homogeneous lithologies and include multiple layers with a high content of hydrogen *** gas composition and stable isotope characteristics vary significantly,but the origin analysis of different gas types has previously been *** on the geochemical parameters of gas samples from different depths and the analysis of geological settings,this research covers the diverse origins of natural gas in different *** gas components are mainly methane with a small amount of C_(2+),and non-hydrocarbon gases,including nitrogen(N_(2)),hydrogen(H_(2)),carbon dioxide(CO_(2)),and helium(He).At greater depth,the carbon isotope of methane becomes heavier,and the hydrogen isotope points to a lacustrine sedimentary *** increasing depth,the origins of N_(2)and CO_(2)change gradually from a mixture of organic and inorganic to *** origins of hydrogen gas are complex and include organic sources,water radiolysis,water-rock(Fe^(2+)-containing minerals)reactions,and *** shales of Denglouku and Shahezi Formations,as source rocks,provide the premise for generation and occurrence of organic ***,the deep faults and fluid activities in Basement Formation control the generation and migration of mantle-derived *** discovery of a high content of H_(2)in study area not only reveals the organic and inorganic association of natural-gas generation,but also provides a scientific basis for the exploration of deep hydrogen-rich gas.

关键词： Gas compositions Stable isotopes Gas origins Hydrogen gas Songliao Basin

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