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Geostatistical modelling and mapping of nematode-based soil ecological quality indices in a polluted nature reserve

Pedosphere 2021年第5期31卷 670-682页

作者： Israel O.IKOYI Gerard B.M.HEUVELINK Ron G.M.DE GOEDE Wageningen University&Research Soil Biology GroupWageningen 6700 AA(The Netherlands) Current address:University of Limerick School of Natural SciencesDepartment of Biological SciencesLimerick V94T9PX(Ireland) Wageningen University&Research Soil Geography and Landscape GroupWageningen 6700 AA(The Netherlands)

Nematodes are indicators of soil quality and soil *** of the relationships between nematode-based soil quality indices and environmental properties is beneficial for assessing environmental threats on soil *** study evaluated the spatial distribution of nematode-based soil quality indices in a 23-ha heavy metal-polluted nature reserve using geostatistical *** expected that a selection of abiotic soil properties(pH and moisture,clay,organic matter,cadmium(Cd),and zinc(Zn)contents)could explain a significant portion of the spatial variation of the indices and that regression kriging could more accurately model their spatial distribution than ordinary kriging.A stratified simple random sampling scheme was used to select 80 locations where soil samples were taken to extract nematodes and derive the *** area had a distinct gradient in soil properties with Cd and Zn content ranging from 0.07 to 68.9 and 5.3 to 1329 mg kg^(-1),*** regression models were fitted to describe the relationships between the indices and soil *** also modelling the spatial correlation structure of regression residuals using spherical semivariograms,regression kriging was used to produce maps of the *** regression models explained between 21% and 44% of the total original variance in the *** pH was a significant explanatory variable in almost all cases,while heavy metal conent had a remarkably low *** some cases,the regression residuals had spatial *** validation indicated that in all cases,regression kriging performed slightly better because of having lower values of the root mean square prediction error and a mean prediction error closer to zero than ordinary *** study showed the importance of soil properties in explaining the spatial distribution of biological soil quality indices in ecological risk assessment.

关键词： ecological risk assessment heavy metals model validation regression kriging semivariance analysis soil property spatial structure

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The Hidden Earthquake Induced Liquefaction Risks in the Rohingya Refugee Camp Hills & Surrounding Areas of Ukhiya, Cox’s Bazar, Bangladesh—A Geotechnical Engineering Approach

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Open Journal of Earthquake Research 2023年第3期12卷 114-138页

作者： Abu Taher Mohammad Shakhawat Hossain Md. Shakil Mahabub Tanmoy Dutta Mahmuda Khatun Toru Terao Md. Hasan Imam Hossain Md Sayem Md. Emdadul Haque Purba Anindita Khan Sheikh Jafia Jafrin Geological Engineering Geohazards & Disaster Sciences Research Group Department of Geological Sciences Jahangirnagar University Dhaka Bangladesh Geological Engineering Geohazards & Disaster Sciences Research Group Department of Geological Sciences Jahangirnagar Univer-sity Dhaka Bangladesh Graduate School of Science for Creative Emergence Kagawa University Kagawa Japan

Liquefaction is one of the major catastrophic geohazards which usually occurs in saturated or partially saturated sandy or silty soils during a seismic event. Evaluating the potential liquefaction risks of a seismically prone area can significantly reduce the loss of lives and damage to civil infrastructures. This research is mainly focused on the earthquake-induced liquefaction risk assessment based on Liquefaction Potential Index (LPI) values at different earthquake magnitudes (M = 5.0, 7.0 and 8.0) with a peak ground acceleration (amax) of 0.28 g in the Rohingya Refugee camp and surrounding areas of Ukhiya, Cox’s Bazar, Bangladesh. Standard Penetration Test (SPT) results have been evaluated for potential liquefaction assessment. The soils are mainly composed of very loose to loose sands with some silts and clays. Geotechnical properties of these very loose sandy soils are very much consistent with the criteria of liquefiable soil. It is established from the grain size analysis results;the soil of the study area is mainly sand dominated (SP) with some silty clay (SC) which consists of 93.68% to 99.48% sand, 0.06% to 4.71% gravel and 0% to 6.26% silt and clay. Some clayey Sand (SC) is also present. The silty clay can be characterized as medium (CI) to high plasticity (CH) inorganic clay soil. LPI values have been calculated to identify risk zones and to prepare risk maps of the investigated area. Based on these obtained LPI values, four (4) susceptible liquefaction risk zones are identified as low, medium, high and very high. The established “Risk Maps” can be used for future geological engineering works as well as for sustainable planning, design and construction purposes relating to adaptation and mitigation of seismic hazards in the investigated area.

关键词： Earthquake Magnitude Factor of Safety (Fs) Liquefaction Potential Index (LPI) & Risk

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Statistical analysis of nitrogen use efficiency in Northeast China using multiple linear regression and Random Forest

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Journal of Integrative Agriculture 2022年第12期21卷 3637-3657页

作者： LIU Ying-xia Gerard B.M.HEUVELINK Zhanguo BAI HE Ping JIANG Rong HUANG Shaohui XU Xin-peng Key Laboratory of Plant Nutrition and Fertilizer Ministry of Agriculture and Rural Affairs/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081P.R.China Soil Geography and Landscape group Wageningen UniversityWageningen 6700 AAThe Netherlands International Soil Reference and Information Centre-World Soil Information Wageningen 6700 AJThe Netherlands

Understanding the spatial-temporal dynamics of crop nitrogen(N)use efficiency(NUE)and the relationship with explanatory environmental variables can support land-use management and ***,the application of statistical models for evaluating the explanatory variables of space-time variation in crop NUE is still *** this study,stepwise multiple linear regression(SMLR)and Random Forest(RF)were used to evaluate the spatial and temporal variation of NUE indicators(i.e.,partial factor productivity of N(PFPN);partial nutrient balance of N(PNBN))at county scale in Northeast China(Heilongjiang,Liaoning and Jilin provinces)from 1990 to *** variables included agricultural management practices,topography,climate,economy,soil and crop *** revealed that the PFPN was higher in the northern parts and lower in the center of the Northeast China and PNBN increased from southern to northern parts during the 1990–2015 *** NUE indicators decreased with time in most counties during the study *** model efficiency coefficients of the SMLR and RF models were 0.44 and 0.84 for PFPN,and 0.67 and 0.89 for PNBN,*** RF model had higher relative importance of soil and climatic covariates and lower relative importance of crop covariates compared to the SMLR *** planting area index of vegetables and beans,soil clay content,saturated water content,enhanced vegetation index in November&December,soil bulk density,and annual minimum temperature were the main explanatory variables for both NUE *** is the first study to show the quantitative relative importance of explanatory variables for NUE at a county level in Northeast China using RF and *** novel study gives reference measurements to improve crop NUE which is one of the most effective means of managing N for sustainable development,ensuring food security,alleviating environmental degradation and increasing farmer’s profitability.

关键词： partial factor productivity of N partial nutrient balance of N stepwise multiple linear regression Random Forest county scale Northeast China

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Quantitative Gas-in-place Comparison of Original and Bitumen-free Lacustrine Shale

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Acta Geologica Sinica(English Edition) 2022年第2期96卷 559-570页

作者： LI Jing ZHOU Shixin FU Deliang CHEN Kefei ZHANG Chen SUN Zexiang LI Pengpeng Northwest Institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhou 730000China Key Laboratory of Petroleum Resources Gansu ProvinceLanzhou 730000China Key Laboratory of Coal Exploration and Comprehensive Utilization Ministry of Nature and ResourcesShaanxi Coal Geology Group CoLtd.Xi’an 710021China University of Chinese Academy of Sciences Beijing 100101China

Residual bitumen in organic-rich shale of oil windows exists widely, and its effect on the gas storage capacity of shale could be two-fold. Bitumen could occupy and block the nanopores of shale, thereby reducing the gas storage capacity. On the other hand, gas could be dissolved in bitumen in shale gas reservoirs, leading to enhanced gas storage capacity. To quantify the effect of bitumen on the gas-in-place(GIP) estimation of lacustrine organic-rich shale, the micropore characteristics and methane sorption capacity of original and bitumen-free shale from the Triassic Yangchang Formation of the Ordos Basin, combined with the methane dissolution capacity for the isolated bitumen, were analyzed and compared. GIP for the original and bitumen-free shale in the depth range of 500–2500 m was evaluated. The results show that micropores in the shale samples were mainly related to organic matter. clay mineral-hosted pores contributed slightly to microporosity. Bitumen significantly reduced the micropore surface area and volume of the original shale, with average percentages of 28.09% and 51.26%, respectively. The methane sorption capacity decreased after bitumen removal. When normalized to the original shale mass, the sum of the methane sorption capacity for bitumen-free shale and the methane dissolution capacity for isolated bitumen was similar to the methane sorption capacity of the original shale, indicating that the lack of methane absorbed on bitumen is the main reason for the decrease in methane sorption capacity after bitumen removal. The contribution of absorbed methane on bitumen to sorbed methane in shale could be higher than 36.23%. Dual effects of bitumen on shale GIP were observed. A high content of bitumen(1.12%) increased the GIP of the shale samples, with an average percentage of 23.5% in the depth range of 500–2500 m, while a low content of bitumen(0.06%) decreased the GIP, with an average percentage of 13.6%.

关键词： lacustrine shale gas-in-place bitumen methane sorption methane dissolution

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Stability of long trench in soft soils by bentonite-water slurry

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Journal of Central South University 2014年第9期21卷 3674-3681页

作者：卓弘春杨宇友张子新潘春晖段创峰 School of Engineering and Technology China University of Geosciences (Beijing) Department of Geotechnical Engineering School of Civil Engineering Tongji University Shanghai Urban Construction (group) Corporation

A series of centrifuge model tests exploring the effects of different types of slurry on long-trench stability in soft clay were conducted. The influence of groundwater conditions relative to trench stability was examined by constructing long trenches using different slurries. The soil deformation and surface settlement induced by the excavation of the trench are found to be closely related to slurry type and excavation depth of the long trench. Increasing the bentonite concentration of the slurry has beneficial effects on stability: 1) larger particles can improve local and global stability in cases where filter cakes do not form, and 2) larger viscosity can promote filter cake formation on the walls of long trenches excavated in soft clay and enhance their stability.

关键词：全局稳定性水泥浆膨润土软土离心模型试验沟槽开挖开挖深度地表沉降

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Microstructure Characterization of a Biogenic Shale Gas Formation——Insights from the Antrim Shale,Michigan Basin

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Journal of Earth Science 2020年第6期31卷 1229-1240页

作者： Kouqi Liu Natalia Zakharova Thomas Gentzis Adedoyin Adeyilola Humberto Carvajal-Ortiz Hallie Fowler Department of Earth and Atmospheric Sciences Central Michigan UniversityMount PleasantMI 48859USA Core Laboratories Reservoir Geology GroupHoustonTX 77040USA

Biogenic gas shales,predominantly microbial in origin,form an important class of organicrich shale reservoirs with a significant economic *** large gaps remain in the understanding of their gas generation,storage,and transport mechanisms,as previous studies have been largely focused on mature thermogenic shale *** this study,the pore structure of 18 Antrim Shale samples was characterized using gas adsorption(CO2 and N2).The results show that most of the Antrim Shale samples are rich in organic matter content(0.58 wt.%to 14.15 wt.%),with highest values found in the Lachine and Norwood *** from the Paxton Member,characterized by lower organic content,have smaller micropore surface area and micropore volume but larger meso-macro pore surface area and *** deconvolution results of the pore size distribution from the N2 adsorption indicate that all of the tested Antrim Shale samples have similar pore *** matter in the Antrim Shale hosts micro pores instead of meso-macro pores,while clay minerals host both micro and meso-macro *** pores play a primary role in the total *** biogenic Antrim Shale,therefore,has different pore structures from other well-studied thermogenic gas shales worldwide.

关键词： gas adsorption Antrim Shale biogenic shale organic matter

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Rheological mechanical properties and its constitutive relation of soft rock considering influence of clay mineral composition and content

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International Journal of Coal Science & Technology 2023年第4期10卷 62-76页

作者： Xuebin Li Xuesheng Liu Yunliang Tan Ai Chen Honglei Wang Xin Wang Shenglong Yang College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of Mining Disaster Prevention and Control Shandong University of Science and TechnologyQingdao 266590China Ningxia Coal Industry Co. Ltd.of China Energy GroupYinchuan 750000China Badong National Observation and Research Station of Geohazards China University of GeosciencesWuhan 430074China

Rheological mechanical properties of the soft rock are afected signifcantly by its main physical characteristics-clay *** this study,taking the mudstone on the roof and foor in four typical mining regions as the research object,frstly,the clay mineral characteristic was analyzed by the X-ray difraction ***,rheological mechanical properties of mudstone samples under diferent confning pressures are studied through triaxial compression and creep *** results show that the clay mineral content of mudstone in diferent regions is diferent,which leads to signifcant diferences in its rheological properties,and these diferences have a good correlation with the content of montmorillonite and illite-montmorillonite mixed *** the montmorillonite content as an example,compared with the sample with 3.56%under the lower stress level,the initial creep deformation of the sample with 11.19%increased by 3.25 times,the viscosity coefcient and longterm strength decreased by 80.59%and 53.94%,***,based on the test results,the damage variation is constructed considering the montmorillonite content and stress level,and the M–S creep damage constitutive model of soft rock is ***,the test results can be ftted with determination coefcients ranging from 0.9020 to 0.9741,which proves that the constitutive relation can refect the infuence of the clay mineral content in the samples *** study has an important reference for revealing the long-term stability control mechanism of soft rock roadway rich in clay minerals.

关键词： clay mineral Physical characteristic Creep Damage Constitutive model

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Maceral evolution of lacustrine shale and its effects on the development of organic pores during low mature to high mature stage:A case study from the Qingshankou Formation in northern Songliao Basin,northeast China

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Petroleum Science 2023年第5期20卷 2709-2725页

作者： Liu Wang Bo Liu Long-Hui Bai Mehdi Ostadhassan Thomas Gentzis Bo-Yang Wang Yi-Zhang Wang Key Laboratory of Continental Shale Hydrocarbon Accumulation and Efficient Development Ministry of EducationNortheast Petroleum UniversityDaqingHeilongjiang163318China Accumulation and Development of Unconventional Oil and Gas State Key Laboratory Cultivation BaseNortheast Petroleum UniversityDaqingHeilongjiang163318China Core Laboratories Reservoir Geology Group6316 Windfern RoadHoustonTX77040USA Exploration and Development Research Institute of Daqing Oilfield Co Ltd DaqingHeilongjiang163712China

Organic matter(OM)hosted pores are crucial for the storage and migration of petroleum in shale *** maturity and macerals type are important factors controlling the development of pores *** this study,six lacustrine shale samples with different thermal maturities from the first member of the Qingshankou Formation in the Songliao Basin,of which vitrinite reflectance(R_(o))ranging from 0.58% to 1.43%,were selected for a comparative *** electron microscopy(SEM)and reflected light microscopy were combined to investigate the development of organic pores in different macerals during thermal *** results show that alginite and liptodetrinite are the dominant primary macerals,followed by *** a few primary organic pores developed in the alginite at the lowest maturity(R_(o)=0.58%).As a result of petroleum generation,oil-prone macerals began to transform to initial-oil solid bitumen at the early oil window(R_(o)=0.73%)and shrinkage cracks were ***-oil solid bitumen cracked to oil,gas and post-oil bitumen by primary cracking(R_(o)=0.98%).Moreover,solid bitumen(SB)was found to be the dominant OM when R_(o)>0.98%,which indicates that SB is the product of oil-prone macerals *** secondary bubble pores were observed on SB,which formed by gas release,while devolatilization cracks developed on migrated ***,at the late oil window(Ro?1.16%),migrated SB filled the interparticle pore *** further increase in temperature,the liquid oil underwent secondary cracking into pyrobitumen and gas,and spongy pores developed on the pyrobitumen at higher levels of maturity(Ro=1.43%),which formed when pyrobitumen cracked into *** and inertinite are stable without any visible pores over the range of maturities,verifying their low petroleum generation *** addition,it was concluded that clay minerals could have a catalytic effect on the petroleum generation,which may explain why or

关键词： Lacustrine shale Maceral evolution Organic pores Scanning electron microscopy Reflected light microscopy

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Development and Application of Mullite Brick With High Refractoriness under Load and Low Creep

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China's Refractories 2000年第4期9卷 31-32页

作者： ZHANGSheng WANGRuikun 等 HenanBoma（group）XinxiangRefractoryFactory Xinxiang453000 HenanBoma（group）XinxiangRefractoryFactory Xi

This paper introduces of the development and applica-tion of heavily burned mullited brick with high reractoriness under load low creep,which is made of andalusie fine and coarse grains (as aggregate),high alumina bauxite produced in Yangquan county,clay produced in Guangxi provine,industrial alumina powder and silliman-ite powder (as matrix material) and a little amount of ad-ditives and bonded with synthetic bond.

关键词：发展趋势莫来石砖耐火材料多铝红柱石低蠕变性低装填

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THE DISCOVERY OF PLIOCENE MAMMALS FROM NIHEWAN AREA AND ITS SIGNIFICANCE

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Chinese Science Bulletin 1982年第9期27卷 990-993页

作者：王安德 Seismogeological Brigade Stare Seismological Bureau Beijingn the summer of 1980 a coordination group found a few fossil vertebrate and mollusc-bearing beds during seismogeological and palaeogeographical investigations at Nihewan of Yangyuan County and Xiyaozhitou of Yuxian County Hebei Province. Preliminary excavations of these beds revealed quite a number of fossils. Before the fifties no fossils were found from the so-called "Hipparion Red Clay". Afterwards

In the summer of 1980, a coordination group found a few fossil vertebrate and mollusc-bearing beds during seismogeological and palaeogeographical investigations at Nihewan of Yangyuan County and Xiyaozhitou of Yuxian County, Hebei Province. Preliminary excavations of these beds revealed quite a number of fossils. Before the fifties no fossils were found from the so-called 'Hipparion Red clay'.

关键词： fossil vertebrate Hebei fauna genera birds strata nodules gravel nodular

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