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Paleoenvironment controls on organic matter accumulation in transitional shales from the eastern Ordos Basin,China

Frontiers of Earth Science 2021年第4期15卷 737-753页

作者： Jianwei LV Songhang ZHANG Ning YANG Chunbo FU Xinlu YAN Yang LI School of Energy Resources China University of GeosciencesBeijing 100083China Chinese Academy of Natural Resources Economics Beijing 101149China Huadian Coal Industry group Co. Ltd.Beijing 100035China Second Oil Production Plant PetroChina Changqing Oilfield CompanyQingyang 745100China

To investigate the paleoenvironmental controls on organic matter accumulation of Upper Paleozoic shales in the eastern Ordos Basin,China,26 shale samples were collected from two wells drilled into the Shanxi and Taiyuan *** total organic carbon(TOC)content,mineral compositions and elemental geochemistry of the samples were ***(35.42%)and clay minerals(48.34%)are the dominant minerals and trace elements(Li,Cs,Cu,V,Co,and Cr)are commonly enriched in the shale samples compared to the Upper Continental Crust.C-values(ranging from 0.2 to 4.5),chemical indices of weathering(CIW)values(48.82 to 99.11),and Sr/Cu ratios(1.00 to 11.05)suggest that the paleoclimate was humid in the study area during the Late *** redox indices(e.g.,Al_(2)O_(3)/(Al_(2)O_(3)+Fe_(2)O_(3)),V/Cr,Ni/Co,V/(V+Ni)and U/Th)indicate a dysoxic to oxic paleoenvironment characterized by transi-tional sedimentary deposits in a continental margin *** addition,chemical index of alteration(CIA,ranging from 77.92%to 98.36%)and CIW(89.19%to 99.11%)values suggest that there was intense chemical weathering in the study area,while the Al_(2)O_(3)-CaO^(*)+Na_(2)O-K_(2)O(A-CN-K)ternary diagram demonstrates that the shales were not subjected to potassium metasomatism during ***_(2)O_(3)/TiO_(2)and TiO_(2)/Zr ratios,as well as REE characteristics suggest a felsic source rocks and discount seawater as an REE *** anomalies indicate an oxic environment with terrigenous input during black shale deposition,and LREE enrichment with negative Eu anomalies suggests that both shale formations were affected by detrital input rather than hydrothermal *** correlation of TOC(ranging from 1.10%to 6.39%,with an average of 2.77%)with trace elemental redox indices(Sr/Cu,Sr/Ba,V/Cr,and U/Th)indicates that a warm-humid,dysoxic to oxic environment preserved much of the organic matter.

关键词： Late Paleozoic shale geochemistry paleoenvironment eastern Ordos Basin

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An intelligent procedure for updating deformation prediction of braced excavation in clay using gated recurrent unit neural networks

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第6期13卷 1485-1499页

作者： Jie Yang Yingjing Liu Saffet Yagiz Farid Laouafa Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong KongChina Zhongtian Construction group Co.Ltd. Hangzhou310008China School of Mining and Geosciences Nazarbayev UniversityNur-Sultan010000Kazakhstan National Institute for Industrial Environment and Risks(INERIS) Verneuil-en-HalatteFrance

This paper aims to establish an intelligent procedure that combines the observational method with the existing deep learning technique for updating deformation of braced excavation in *** gated recurrent unit(GRU) neural network is adopted to formulate the forecast model and learn the potential rules in the field observations using the Nesterov-accelerated Adam(Nadam) *** the proposed procedure,the GRU-based forecast model is first trained based on the field data of previous and current ***,the field data of the current stage are used as input to predict the deformation response of the next stage via the previously trained GRU-based forecast *** updating process will loop up till the end of the *** procedure has the advantage of directly predicting the deformation response of unexcavated stages based on the monitoring *** proposed intelligent procedure is verified on two well-documented cases in terms of accuracy and *** results indicate that both wall deflection and ground settlement are accurately predicted as the excavation ***,the advantages of the proposed intelligent procedure compared with the Bayesian/o ptimization updating are illustrated.

关键词： Braced excavation Deep learning clay Wall deflection Ground settlement Deformation updating

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Ceramsite Containing Iron Oxide and its Use as Functional Aggregate in Microwave Absorbing Cement-based Materials

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Journal of Wuhan University of Technology(Materials Science) 2018年第1期33卷 133-138页

作者：何永佳 LI Guangfeng 李洪斌 Lü Linnü HE Liu State Key Laboratory of Silicate Materials for Architectures Wuhan University of Technology School of Materials Science and Engineering Wuhan University of Technology Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics School of Science Wuhan University of Technology China Railway Eleventh Bureau group Fifth Engineering Co. Ltd.

Electromagnetic（EM） wave absorbing cement-based composite has promising applications in protecting civil and military buildings from electromagnetic interferences. A new idea of preparing EM wave absorbing cement-based composite is proposed by using ceramsite containing iron oxide as EM wave absorbing functional aggregate. The ceramsite was synthesized by adding 10 wt% Fe3O4 into clay and sintering at 1 200 ℃, which shows obvious dielectric and magnetic loss properties for electromagnetic wave. The maximum reflection loss（RL） of the concrete specimens prepared with the ceramsite is between-10.2--10.7 dB（corresponding to absorption greater than 90% EM energy） in the bandwidth of 8-18 GHz. In addition, the compressive strength at 28 days age of the concrete is 46 MPa, showing the potentiality of being used as structural components in buildings.

关键词： electromagnetic absorption iron oxide ceramsite functional aggregate concrete

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Soil nutrient loss due to tuber crop harvesting and its environmental impact in the North China Plain

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Journal of Integrative Agriculture 2016年第7期15卷 1612-1624页

作者： YU Han-qing LI Yong ZHOU Na Adrian Chappell LI Xiao-yu Jean Poesen Agricultural Clean Watershed Research group Institute of Environment and Sustainable Development in AgricultureChinese Academy of Agricultural Sciences(CAA S)Beijing 100081P.R.China CSIRO Land&Water National Research Flagship Canberra ACT 2601Australia Division of Geography KU LeuvenHeverlee 3001Belgium

Soil loss due to crop harvesting （SLCH） is a soil erosion process that signiifcantly contributes to soil degradation in crop-lands. However, little is known about soil nutrient losses caused by SLCH and its environmental impacts. In the North China Plain area, we measured the losses of soil organic carbon （SOC） and nitrogen as wel as phosphorus due to SLCH and assessed their relationship with soil particle size composition, agronomic practices and soil moisture content. Our results show that the losses by harvesting potato of SOC, total nitrogen （TN）, available nitrogen （AN）, available phosphorus （AP） and total phosphorus （TP） were 1.7, 1.8, 1.8, 15.9 and 14.1 times compared by harvesting sweet potato, respectively. The variation of SOC, N and P loss by SLCH are mainly explained by the variation of plant density （PD）（17–50%）, net mass of an individual tuber （Mcrop/p）（16–74%）, soil clay content （34–70%） and water content （19–46%）. Taking into account the current sewage treatment system and the ratio of the nutrients adhering to the tubers during transportation from the ifeld （NTRP/SP）, the loss of TN and TP by harvesting of potato and sweet potato in the North China Plain area amounts to 3% N and 20% P loads in the water bodies of this region. The fate of the exported N and P in the sewage treatment system ultimately controls the contribution of N and P to the polution of lakes and rivers. Our results suggest that a large amount of SLCH-induced soil nutrient export during transportation from the ifeld is a potential polutant source for agricultural water for vast planting areas of tuber crops in China, and should not be overlooked.

关键词： soil nutrient losses potato sweet potato crop harvesting water polution

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Interaction of radionuclides with natural and manmade materials using XAFS technique

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Science China Chemistry 2017年第2期60卷 170-187页

作者： Shujun Yu Xiangxue Wang Shitong Yang Guodong Sheng Ahmed Alsaedi Tasawar Hayat Xiangke Wang School of Environment and Chemical Engineering North China Electric Power UniversityBeijing 102206China Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions Suzhou 215123China College of Chemistry and Chemical Engineering Shaoxing UniversityShaoxing 312000China Nonlinear Analysis and Applied Mathematics(NAAM)Research group Faculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia

The X-ray absorption fine structure(XAFS)technology has exhibited a very unique application in the study of sorption mechanism,chemical species and microstructures of radionuclides at the natural solid-water *** this review,the interaction mechanism of radionuclides with clay minerals and nanomaterials under different environmental conditions are summarized from the XAFS spectroscopy *** coordination number and the bond distances of radionuclides,the oxidation-reduction reactions,the influence of humic substances and microorganisms on the species and structures of radionuclides at molecule level are reviewed and *** review is helpful to understand the interactions of radionuclides with oxides,natural clay minerals and nanomaterials,which is also crucial to evaluate the physicochemical behaviors of radionuclides in the natural environment.

关键词：放射性核素 XAFS 纳米材料自然环境相互作用 X射线吸收精细结构技术氧化还原反应

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Modelling impacts of acid deposition and groundwater level on habitat quality and plant species diversity

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Ecological Processes 2016年第1期5卷 273-291页

作者： J.Kros J.P.Mol-Dijkstra G.W.W.Wamelink G.J.Reinds Avan Hinsberg W.de Vries Wageningen Environmental Research Wageningen University and ResearchP.O.Box 476700 AA WageningenThe Netherlands Netherlands Environmental Assessment Agency PO Box 3033720 BABilthovenWageningenThe Netherlands Environmental Systems Analysis group Wageningen University and ResearchP.O.Box 476700 AA WageningenThe Netherlands

Introduction:We quantified the effects of the site factors pH and nitrate(NO_(3))concentration in soil solution and groundwater level on the vegetation of terrestrial ecosystems for the Netherlands in response to changes in atmospheric nitrogen(N)and sulphur(S)deposition and groundwater level over the period *** assessment was made with the SMART2 model,a simple one-layer model including geochemical buffer processes,element cycling by litterfall,mineralisation and uptake,nitrogen transformation processes and element input through deposition,weathering and upward ***:To assess the effects of changes in abiotic site factors on the vegetation,we developed a simple plant diversity indicator for grassland,heathland and forest,based on the occurrence of target plant species and competing *** occurrence was calculated from the preferred ranges of each species for the NO_(3) concentration and pH in soil solution and mean spring groundwater *** in the plant diversity indicator were assessed from effects of changes in the occurrence of target and competing plant species in response to changes in mean spring groundwater level and in pH and NO_(3) concentration,as calculated with *** were made for combinations of five vegetation structure types(three forest types,semi-natural grassland and heathland)and seven soil types(three sandy soils,two clay soils,peat and loess soils)using a 250×250 m *** used data for atmospheric deposition and groundwater level in the past to assess trends between 1990 and 2010 and evaluated two future scenarios for the period 2010-2030:a Business as Usual and an Improved Environment ***:Comparison of model predictions on pH and NO_(3) with measured soil solution concentrations for forest showed a reasonable to good agreement for pH but rather poor for NO_(3).The largest impacts were found for the combination of the two Improved Environment ***:Reductions in N

关键词： Nutrient cycling Soil modelling Biodiversity Acidification Scenario analysis

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Water protection in the western semiarid coal mining regions of China: A case study

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International Journal of Mining Science and Technology 2012年第5期22卷 719-723页

作者： Huang Hanfu Wang Changshen Bai Haibo Wang Zihe State Key Laboratory of Geomechanics & Deep Underground Engineering China University of Mining & Technology Xuzhou 221008 China Sima Coal Mine Lu'an Mining Group Co. Ltd. Changzhi 047105 China School of Resource & Geosciences China University of Mining & Technology Xuzhou 221116 China

The coal industry in China has been moving from the semiarid eastern to the drier western regions since the beginning of this *** protection is of the utmost concern for coal mining in these ***'an,as one of the state coal mining bases in China,has been seeing increasingly heavier pressure for the protection of water *** article considers Lu'an as an example and describes the ways these concerns may be *** mine-water utilization rates have effectively reduced wasting of water and,consequently,have reduced water *** the top layers of the Ordavician as aquifuge barriers can prevent floor karst water inrush into the longwall face and can protect the regional Ordovician karst water resources at the same *** strength of the overlying Quaternary clay can protect against roof collapse and has successfully preserved the Quaternary porous water resource.

关键词：水资源保护半干旱区煤炭开采西部地区中国案例保护水资源综采工作面

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Biological weathering of phlogopite during enriched vermicomposting

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Pedosphere 2021年第3期31卷 440-451页

作者： Fariba JAFARI Hossein KHADEMI Vajihe SHAHROKH Angel FAZ CANO Jose A.ACOSTA Farhad KHORMALI Department of Soil Science College of AgricultureIsfahan University of TechnologyIsfahan 84156-83111Iran Sustainable Use Management and Reclamation of Soil and Water Research GroupUniversidad Politécnica de CartagenaPaseo Alfonso ⅩⅢ48CartagenaMurcia 30203Spain Department of Soil Science Gorgan University of Agricultural Science and Natural ResourcesGorgan 49189-43464Iran

As the dominant macrofauna in many soils,earthworms play a significant role in mineral weathering and nutrient release from mineral structures into available forms for root *** is a trioctahedral micaceous mineral that can be weathered to other minerals through release of its interlayer potassium(K).In this study,we investigated the effect of earthworm activities and associated microbial communities on phlogopite weathering during the production of phlogopite-enriched vermicompost with different quantities of phlogopite *** experiment was run under laboratory conditions using three levels of phlogopite(0,20%and 40%by weight)in *** Petri dish contained 20 g of a mixture of cow manure and phlogopite,and vermicomposting process was performed by inoculation of eight Eisenia foetida *** in clay mineralogy and C/N ratio in each dish were assessed at days 0,45,90,135,and 180 during *** results indicated that phlogopite was partially weathered to vermiculite and interstratified mica-vermiculite during the vermicomposting *** rate of weathering was higher during the early stages of vermicomposting(the first 90 d).The weathering of phlogopite was influenced considerably by the activity of earthworms and associated microbial communities during the organic matter transformation *** the early stages of the process,the weathering rate for different levels of phlogopite was not significantly different,but over time it accelerated steadily,and the difference increased.

关键词： C/N ratio earthworm Eisenia foetida enriched vermicompost mineral weathering weathering rate X-ray diffraction

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Soil type limits population abundance of rodents in crop fields:case study of the multimammate rat Mastomys natalensis Smith,1834 in Tanzania

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Integrative Zoology 2008年第1期3卷 27-30页

作者： Apia W.MASSAWE Winnie RWAMUGIRA Herwig LEIRS Rhodes H.MAKUNDI Loth MULUNGU V.NGOWO Robert MACHANG’U Pest Management Centre Sokoine University of AgricultureMorogoroTanzania Crop Science and Production Sokoine University of AgricultureMorogoroTanzania Evolutionary Biology group University of AntwerpAntwerpBelgium Danish Pest Infestation Laboratory Danish Institute of Agricultural SciencesKongens LyngbyDenmark Rodent Control Centre MorogoroTanzania

Studies of populations of the multimammate rat Mastomys natalensis in Morogoro, Tanzania, show that soil textureappears to influence the population abundance and distribution of these rats in agricultural fields. The lowest rodentpopulation abundance was found on sandy clay soils (F(2, 5) = 8.42;P = 0.025). The population abundances of *** on sandy clay loam and sandy loam soils did not differ significantly (P ≤ 0.05), possibly because thesesoils have a very similar texture. The results of this study suggest that M. natalensis prefers loam-textured soilswith a high percentage of sand, which are probably better than clay soils for burrowing and nesting, particularly inthe rainy season. The lower preference for clay soils is probably related to the poor aeration in these soils and thewaterlogging that occurs during the wet season.

关键词： Mastomys population soil texture Tanzania.

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Effect of cyclic wetting-drying on tensile mechanical behavior and microstructure of clay-bearing sandstone

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International Journal of Coal Science & Technology 2021年第5期8卷 956-968页

作者： Pingye Guo Juan Gu Yi Su Jiong Wang Zhanwen Ding State Key Laboratory for Geo-Mechanics and Deep Underground Engineering Beijing 100083China School of Mechanics Architecture and Civil EngineeringChina University of Mining and TechnologyBeijing 100083China Tang Steel International Engineering Technology Corp Tangshan 063000China China Henan Geological and Mineral Resources Construction Engineering(group)Co. LtdZhengzhou 450007China

The understanding of the weakening mechanism of tensile strength of rock subjected to cyclic wetting-drying is critical for rock *** strength tests were conducted on a total of 35 sandstone specimens with different wetting-drying *** crack propagation process and acoustic emission characteristics of the tested samples were obtained through a high-speed camera and acoustic emission *** results indicate that the tensile strength is observably reduced after cyclic wetting-drying,and the extent of the reduction is not only related to the number of wettingdrying cycle,but also closely related to the clay mineral content of the *** addition,as the cycles of wetting-drying increase,the effect of each single cycle on tensile strength get reduced until it becomes ***,the crack initiation and penetration time is prolonged as the number of wetting-drying cycle increases,which indicates that cyclic wetting-drying weakens the rock stiffness and enhances the ductility of ***,the acoustic emission characteristics of the tested samples further confirmed the ductile behaviour of the sandstone samples with increasing wetting-drying ***,through the analysis of the microstructure and mineral composition of the samples with different wetting-drying cycles,it is concluded that the main weakening mechanisms of sandstones containing clay minerals are frictional reduction,chemical and corrosive deterioration.

关键词： Sandstone Wetting-drying cycle Tensile strength Weakening mechanism Failure characteristics

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