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Localization for mixed near-field and far-field sources under impulsive noise
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作者 GAO Hongyuan ZHANG Yuze +2 位作者 DU Ya’nan CHENG Jianhua CHEN Menghan 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第2期302-315,共14页
In order to solve the problem that the performance of traditional localization methods for mixed near-field sources(NFSs)and far-field sources(FFSs)degrades under impulsive noise,a robust and novel localization method... In order to solve the problem that the performance of traditional localization methods for mixed near-field sources(NFSs)and far-field sources(FFSs)degrades under impulsive noise,a robust and novel localization method is proposed.After eliminating the impacts of impulsive noise by the weighted out-lier filter,the direction of arrivals(DOAs)of FFSs can be estimated by multiple signal classification(MUSIC)spectral peaks search.Based on the DOAs information of FFSs,the separation of mixed sources can be performed.Finally,the estimation of localizing parameters of NFSs can avoid two-dimension spectral peaks search by decomposing steering vectors.The Cramer-Rao bounds(CRB)for the unbiased estimations of DOA and range under impulsive noise have been drawn.Simulation experiments verify that the proposed method has advantages in probability of successful estimation(PSE)and root mean square error(RMSE)compared with existing localization methods.It can be concluded that the proposed method is effective and reliable in the environment with low generalized signal to noise ratio(GSNR),few snapshots,and strong impulse. 展开更多
关键词 source localization far-field source(NFS) near-field source(FFS) impulsive noise Cramer-Rao bound(CRB)
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Enhancing microseismic/acoustic emission source localization accuracy with an outlier-robust kernel density estimation approach
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作者 Jie Chen Huiqiong Huang +4 位作者 Yichao Rui Yuanyuan Pu Sheng Zhang Zheng Li Wenzhong Wang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第7期943-956,共14页
Monitoring sensors in complex engineering environments often record abnormal data,leading to significant positioning errors.To reduce the influence of abnormal arrival times,we introduce an innovative,outlier-robust l... Monitoring sensors in complex engineering environments often record abnormal data,leading to significant positioning errors.To reduce the influence of abnormal arrival times,we introduce an innovative,outlier-robust localization method that integrates kernel density estimation(KDE)with damping linear correction to enhance the precision of microseismic/acoustic emission(MS/AE)source positioning.Our approach systematically addresses abnormal arrival times through a three-step process:initial location by 4-arrival combinations,elimination of outliers based on three-dimensional KDE,and refinement using a linear correction with an adaptive damping factor.We validate our method through lead-breaking experiments,demonstrating over a 23%improvement in positioning accuracy with a maximum error of 9.12 mm(relative error of 15.80%)—outperforming 4 existing methods.Simulations under various system errors,outlier scales,and ratios substantiate our method’s superior performance.Field blasting experiments also confirm the practical applicability,with an average positioning error of 11.71 m(relative error of 7.59%),compared to 23.56,66.09,16.95,and 28.52 m for other methods.This research is significant as it enhances the robustness of MS/AE source localization when confronted with data anomalies.It also provides a practical solution for real-world engineering and safety monitoring applications. 展开更多
关键词 Microseismic source/acoustic emission(MS/AE) Kernel density estimation(KDE) Damping linear correction source location Abnormal arrivals
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Hydrocarbon Generation Characteristics of Coal-measure Source Rocks and their Contribution to Natural Gas:A Case Study of Middle and Lower Jurassic Targets from the Southern Junggar Basin Margin
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作者 YU Miao GAO Gang +6 位作者 LIU Miao MA Wanyun TIAN Anqi FAN Keting GUO Liulinbo HE Dan ZHANG Youjin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第5期1270-1284,共15页
In order to study the hydrocarbon generation(HCGE)characteristics of coal-bearing basins,the coal-measure source rocks of the Middle Jurassic-Lower Jurassic(MLJ)of the piedmont thrust belt in the southern margin of th... In order to study the hydrocarbon generation(HCGE)characteristics of coal-bearing basins,the coal-measure source rocks of the Middle Jurassic-Lower Jurassic(MLJ)of the piedmont thrust belt in the southern margin of the Junggar Basin in Northwest China are taken as research objects.More than 60 MLJ samples were collected from outcrops and wells.Total organic carbon(TOC),rock pyrolysis(Rock-Eval),organic petrological,vitrinite reflectance(%Ro),and hydrous pyrolysis were performed to analyze the relevant samples.The pyrolysis gases and liquid products were measured,and then the chemical composition,as well as carbon isotopes of the gases,were analyzed.The results indicate that the MLJ source rocks have the capacity for large-scale gas generation.In addition,for coal-measure source rocks,the heavier the carbon isotope of kerogen(δ^(13)C_(kerogen)),the lower the liquid hydrocarbon and hydrocarbon gas yield,and the easier it is to produce non-hydrocarbon gas.It is worth noting that when theδ^(13)C_(kerogen)in organic matter(OM)is relatively heavier,the fractionation of its products may become weaker in the evolutionary process.The vital contribution of the MLJ source rock to natural gas resources in the study area was further confirmed by comparing it with the Jurassic source gas. 展开更多
关键词 upstream natural resources/energy coal-bearing basins source rock hydrous pyrolysis carbon isotope JURASSIC Xinjiang province
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Experimental results of a magnetic field modification to the radio frequency driver of a negative ion source
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作者 谢俊炜 谢亚红 +6 位作者 韦江龙 梁立振 彭旭峰 杨宇雯 顾玉明 胡纯栋 谢远来 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第4期162-167,共6页
A magnetic field produced by a current flowing through the plasma grid(PG) is one of the solutions to reduce the collisional loss of negative ions in a negative ion source, which reduces the electron temperature in fr... A magnetic field produced by a current flowing through the plasma grid(PG) is one of the solutions to reduce the collisional loss of negative ions in a negative ion source, which reduces the electron temperature in front of the PG. However, the magnetic field diffused into the driver has some influence on the plasma outflowing. In order to investigate the effect of changing this magnetic field on the outflowing of plasma from the driver, a circular ring(absorber) of high permeability iron has been introduced at the driver exit, which can reduce the magnetic field around it and improve plasma outflowing. With the application of the absorber, the electron density is increased by about 35%, and the extraction current measured from the extraction grid is increased from 1.02 A to 1.29 A. The results of the extraction experiment with cesium injection show that both the extraction grid(EG) current and H-current are increased when the absorber is introduced. 展开更多
关键词 neutral beam injection negative ion source magnetic filter radio frequency ion source
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Assessing the role of forest resources in improving rural livelihoods in West Bengal of India
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作者 Soumen BISUI Pravat Kumar SHIT 《Regional Sustainability》 2024年第2期75-88,共14页
Forest resources play a vital role in supporting the livelihoods of rural communities residing in forest-rich areas.In India,a forest-rich country,a significant proportion of non-timber forest products(NTFPs)is consum... Forest resources play a vital role in supporting the livelihoods of rural communities residing in forest-rich areas.In India,a forest-rich country,a significant proportion of non-timber forest products(NTFPs)is consumed locally,supporting numerous rural communities relying on forests for essential resources,such as firewood,timber,and NTFPs.This study focuses on two forest-dominant districts in West Bengal of India,namely,Jhargram District and Paschim Medinipur District.Furthermore,this study aims to enhance the understanding of forest-dependent communities by comparing the standard of living among different village classes.Thus,we categorized villages into three classes based on the distance from home to forests,including inner villages,fringe villages,and outer villages.Through focus group discussions and household surveys,we explored the sources of local economy,income sources of household,and reasons for economic diversification in different village classes.The study findings confirm that substantial variations existed in the income sources and the standard of living in these villages.Forest income varied dramatically among the three village classes,with inner villages having greater forest income than fringe villages and outer villages.Meanwhile,households in outer villages depended on forests and engaged in diverse economic activities for their livelihoods.Compared with inner and fringe villages,households in outer villages derived a significant portion of their income from livestock.This discrepancy can be attributed to challenges,such as inadequate transportation,communication,and underdeveloped market chains in inner villages.Moreover,these findings emphasize the need to develop sustainable forest management practices,create alternative income-generation opportunities,and improve infrastructure and market access in inner villages,as well as promote economic diversification in outer villages.Through targeted policy measures,these forest-rich regions can achieve improved livelihoods,enhanced standard of living,and increased resilience for their communities. 展开更多
关键词 Non-timber forest products(NTFPs) Forest resources Standard of living INDEX LIVELIHOOD dependency index Income sources INDIA
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Ecological Remediation Measures for Non-point Source Pollution Based on Source-Sink Landscape Theory: A Case Study of Huanghou Basin
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作者 WANG Hao XIAO Shizhen 《Journal of Landscape Research》 2024年第2期72-76,共5页
The growth of society and population has led to a range of water pollution issues.Among these,non-point source pollution assessment and treatment pose a particular challenge due to its formation mechanism.This has bec... The growth of society and population has led to a range of water pollution issues.Among these,non-point source pollution assessment and treatment pose a particular challenge due to its formation mechanism.This has become a focal point and challenge in water pollution treatment research.The study area for this research was the Huanghou basin in Guizhou Province,southwest China.The land use type of the basin was analyzed using remote sensing technology,and water quality data was collected by distributing points throughout the basin,based on source-sink landscape theory.The distribution map of the basin’s source-sink landscape and the results of water quality data accurately and efficiently identified the areas with high risk of non-point source pollution in the western and southwestern residential and agricultural areas of the upper basin.Hence,a strategy of“increasing sinks and decreasing sources”was proposed.The strategy was implemented at both macro and micro levels to address non-point source pollution in the basin using ecological remediation techniques.The work to control karst rocky desertification should continue at a macro level.The rocky desertification area in the basin should gradually transform into grassland and forested land,while increasing the overall area of the sink landscape.Ecological restoration techniques,such as slope planting,riparian zone vegetation restoration,increasing plant abundance,and restoring aquatic plants,can effectively control non-point source pollution at the micro level.Compared to traditional control methods,this remediation strategy focuses on source and process control.It is more effective and does not require large-scale water pollution control projects,which can save a lot of environmental control funds and management costs.Therefore,it has greater research significance and application value. 展开更多
关键词 source-sink landscape theory Non-point source pollution Ecological restoration Rocky desertification control Karst basin
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Applying Source Parameter Imaging (SPI) to Aeromagnetic Data to Estimate Depth to Magnetic Sources in the Mamfe Sedimentary Basin
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作者 Eric N. Ndikum Charles T. Tabod 《International Journal of Geosciences》 CAS 2024年第1期1-11,共11页
Aeromagnetic data over the Mamfe Basin have been processed. A regional magnetic gridded dataset was obtained from the Total Magnetic Intensity (TMI) data grid using a 3 × 3 convolution (Hanning) filter to remove ... Aeromagnetic data over the Mamfe Basin have been processed. A regional magnetic gridded dataset was obtained from the Total Magnetic Intensity (TMI) data grid using a 3 × 3 convolution (Hanning) filter to remove regional trends. Major similarities in magnetic field orientation and intensities were observed at identical locations on both the regional and TMI data grids. From the regional and TMI gridded datasets, the residual dataset was generated which represents the very shallow geological features of the basin. Processing this residual data grid using the Source Parameter Imaging (SPI) for magnetic depth suggests that the estimated depths to magnetic sources in the basin range from about 271 m to 3552 m. The highest depths are located in two main locations somewhere around the central portion of the study area which correspond to the area with positive magnetic susceptibilities, as well as the areas extending outwards across the eastern boundary of the study area. Shallow magnetic depths are prominent towards the NW portion of the basin and also correspond to areas of negative magnetic susceptibilities. The basin generally exhibits a variation in depth of magnetic sources with high, average and shallow depths. The presence of intrusive igneous rocks was also observed in this basin. This characteristic is a pointer to the existence of geologic resources of interest for exploration in the basin. 展开更多
关键词 Mamfe Basin Aeromagnetic Data source Parameter Imaging (SPI) Depth to Magnetic sources
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Geochemical identification of a source rock affected by migrated hydrocarbons and its geological significance:Fengcheng Formation,southern Mahu Sag,Junggar Basin,NW China 被引量:2
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作者 Wen-Long Dang Gang Gao +5 位作者 Xin-Cai You Ke-Ting Fan Jun Wu De-Wen Lei Wen-Jun He Yong Tang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期100-114,共15页
The Fengcheng Formation is a crucial source rock and the primary reservoir for oil accumulation in the Mahu Sag.Crude oils are distributed throughout the Fengcheng Formation,ranging from the edge to the interior of th... The Fengcheng Formation is a crucial source rock and the primary reservoir for oil accumulation in the Mahu Sag.Crude oils are distributed throughout the Fengcheng Formation,ranging from the edge to the interior of the sag in the southern Mahu Sag.These crude oils originate from in-situ source rocks in shallowly buried areas and the inner deep sag.During migration,the crude oil from the inner deep sag affects the source rocks close to carrier beds,leading to changes in the organic geochemical characteristics of the source rocks.These changes might alter source rock evaluations and oil-source correlation.Based on data such as total organic carbon(TOC),Rock-Eval pyrolysis of source rocks,and gas chromatography-mass spectrometry(GC-MS)of the saturated fraction,and considering the geological characteristics of the study area,we define the identification characteristics of source rock affected by migrated hydrocarbons and establish the various patterns of influence that migrated hydrocarbons have on the source rock of the Fengcheng Formation in the southern Mahu Sag.The source rocks of the Fengcheng Formation are mostly fair to good,containing mainly Type II organic matter and being thermally mature enough to generate oil.Source rocks affected by migrated hydrocarbons exhibit relatively high hydrocarbon contents(S1/TOC>110 mg HC/g TOC,Extract/TOC>30%,HC:hydrocarbon),relatively low Rock-Eval Tmax values,and relatively high tricyclic terpane contents with a descending and mountain-shaped distribution.Furthermore,biomarker composition parameters indicate a higher thermal maturity than in-situ source rocks.Through a comparison of the extract biomarker fingerprints of adjacent reservoirs and mudstones in different boreholes,three types of influence patterns of migrated hydrocarbons are identified:the edge-influence of thin sandstone-thick mudstone,the mixed-influence of sandstone-mudstone interbedded,and the full-influence of thick sandstone-thin mudstone.This finding reminds us that the influence of migrated hydrocarbons must be considered when evaluating source rocks and conducting oil-source correlation. 展开更多
关键词 Organic geochemistry source rock Influence of migrated hydrocarbons Fengcheng Formation Southern Mahu Sag
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A Review on Sources,Extractions and Analysis Methods of a Sustainable Biomaterial:Tannins 被引量:2
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作者 Antonio Pizzi Marie-Pierre Laborie Zeki Candan 《Journal of Renewable Materials》 EI CAS 2024年第3期397-425,共29页
Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly ... Condensed and hydrolysable tannins are non-toxic natural polyphenols that are a commercial commodity industrialized for tanning hides to obtain leather and for a growing number of other industrial applications mainly to substitute petroleum-based products.They are a definite class of sustainable materials of the forestry industry.They have been in operation for hundreds of years to manufacture leather and now for a growing number of applications in a variety of other industries,such as wood adhesives,metal coating,pharmaceutical/medical applications and several others.This review presents the main sources,either already or potentially commercial of this forestry by-materials,their industrial and laboratory extraction systems,their systems of analysis with their advantages and drawbacks,be these methods so simple to even appear primitive but nonetheless of proven effectiveness,or very modern and instrumental.It constitutes a basic but essential summary of what is necessary to know of these sustainable materials.In doing so,the review highlights some of the main challenges that remain to be addressed to deliver the quality and economics of tannin supply necessary to fulfill the industrial production requirements for some materials-based uses. 展开更多
关键词 TANNINS FLAVONOIDS sourceS extraction methods analysis methods
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Time-lagged Effects of the Spring Atmospheric Heat Source over the Tibetan Plateau on Summer Precipitation in Northeast China during 1961–2020:Role of Soil Moisture 被引量:1
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作者 Yizhe HAN Dabang JIANG +2 位作者 Dong SI Yaoming MA Weiqiang MA 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第8期1527-1538,共12页
The spring atmospheric heat source(AHS)over the Tibetan Plateau(TP)has been suggested to affect the Asian summer monsoon and summer precipitation over South China.However,its influence on the summer precipitation in N... The spring atmospheric heat source(AHS)over the Tibetan Plateau(TP)has been suggested to affect the Asian summer monsoon and summer precipitation over South China.However,its influence on the summer precipitation in Northeast China(NEC)remains unknown.The connection between spring TP AHS and subsequent summer precipitation over NEC from 1961 to 2020 is analyzed in this study.Results illustrate that stronger spring TP AHS can enhance subsequent summer NEC precipitation,and higher soil moisture in the Yellow River Valley-North China region(YRVNC)acts as a bridge.During spring,the strong TP AHS could strengthen the transportation of water vapor to East China and lead to excessive rainfall in the YRVNC.Thus,soil moisture increases,which regulates local thermal conditions by decreasing local surface skin temperature and sensible heat.Owing to the memory of soil moisture,the lower spring sensible heat over the YRVNC can last until mid-summer,decrease the land–sea thermal contrast,and weaken the southerly winds over the East Asia–western Pacific region and convective activities over the South China Sea and tropical western Pacific.This modulates the East Asia–Pacific teleconnection pattern,which leads to a cyclonic anomaly and excessive summer precipitation over NEC. 展开更多
关键词 Tibetan Plateau atmospheric heat source Northeast China summer precipitation soil moisture
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The coupling control of biological precursors and environmental factors onβ-carotane enrichment in alkaline lacustrine source rocks:A case study from the Fengcheng formation in the western Junggar Basin,NW China 被引量:1
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作者 Mao-Guo Hou Ming Zha +5 位作者 Hua Liu Hai-Lei Liu Jiang-Xiu Qu Ablimit Imin Xiu-Jian Ding Zhong-Fa Jiang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期836-854,共19页
The organic-rich mudstones and dolostones of the Permian Fengcheng Formation(Fm.)are typically alkaline lacustrine source rocks,which are typified by impressively abundantβ-carotane.Abundant β-carotane has been well... The organic-rich mudstones and dolostones of the Permian Fengcheng Formation(Fm.)are typically alkaline lacustrine source rocks,which are typified by impressively abundantβ-carotane.Abundant β-carotane has been well acknowledged as an effective indicator of biological sources or depositional environments.However,the specific biological sources of β-carotane and the coupling control of biological sources and environmental factors on the enrichment of β-carotane in the Fengcheng Fm.remains obscure.Based on a comprehensive investigation of the bulk,molecular geochemistry,and organic petrology of sedimentary rocks and the biochemistry of phytoplankton in modern alkaline lakes,we proposed a new understanding of the biological precursors of β-carotane and elucidated the enrichment mechanism of β-carotane in the Fengcheng Fm.The results show that the biological precursors crucially control the enrichment of β-carotane in the Fengcheng Fm.The haloalkaliphilic cyanobacteria are the primary biological sources of β-carotane,which is suggested by a good positive correlation between the 2-methylhopane index,7-+8-methyl heptadecanes/C_(max),C_(29%),and β-carotane/C_(max)in sedimentary rocks and the predominance of cyanobacteria with abundantβ-carotene in modern alkaline lakes.The enrichment of β-carotane requires the reducing condition,and the paleoredox state that affects the enrichment of β-carotane appears to have a threshold.The paleoclimate conditions do not considerably impact the enrichment of β-carotane,but they have some influence on the water's paleosalinity by affecting evaporation and precipitation.While it does not directly affect the enrichment of β-carotane in the Fengcheng Fm.,paleosalinity does have an impact on the cyanobacterial precursor supply and the preservation conditions. 展开更多
关键词 β-carotane enrichment Cyanobacterial input Environmental impact Alkaline lacustrine source rocks The Fengcheng formation
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Quantitative effect of kerogen type on the hydrocarbon generation potential of Paleogene lacustrine source rocks,Liaohe Western Depression,China 被引量:1
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作者 Sha-Sha Hui Xiong-Qi Pang +7 位作者 Fu-Jie Jiang Chen-Xi Wang Shu-Xing Mei Tao Hu Hong Pang Min Li Xiao-Long Zhou Kan-Yuan Shi 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期14-30,共17页
Kerogen types exert a decisive effect on the onset and capacity of hydrocarbon generation of source rocks.Lacustrine source rocks in the Liaohe Western Depression are characterized by thick deposition,high total organ... Kerogen types exert a decisive effect on the onset and capacity of hydrocarbon generation of source rocks.Lacustrine source rocks in the Liaohe Western Depression are characterized by thick deposition,high total organic carbon(TOC)content,various kerogen types,and a wide range of thermal maturity.Consequently,their hydrocarbon generation potential and resource estimation can be misinterpreted.In this study,geochemical tests,numerical analysis,hydrocarbon generation kinetics,and basin modeling were integrated to investigate the differential effects of kerogen types on the hydrocarbon generation potential of lacustrine source rocks.Optimized hydrocarbon generation and expulsion(HGE)models of different kerogen types were established quantitatively upon abundant Rock-Eval/TOC/vitrinite reflectance(R_(o))datasets.Three sets of good-excellent source rocks deposited in the fourth(Es4),third(Es3),and first(Es1)members of Paleogene Shahejie Formation,are predominantly types I-II_(1),II_(1)-II_(2),and II-III,respectively.The activation energy of types I-II_(2)kerogen is concentrated(180-230 kcal/mol),whereas that of type III kerogen is widely distributed(150-280 kcal/mol).The original hydrocarbon generation potentials of types I,II_(1),II_(2),and III kerogens are 790,510,270,and 85 mg/g TOC,respectively.The Ro values of the hydrocarbon generation threshold for type I-III source rocks gradually increase from 0.42%to 0.74%,and Ro values of the hydrocarbon expulsion threshold increase from 0.49%to 0.87%.Types I and II_(1)source rocks are characterized by earlier hydrocarbon generation,more rapid hydrocarbon expulsion,and narrower hydrocarbon generation windows than types II_(2)and III source rocks.The kerogen types also affect the HGE history and resource potential.Three types(conventional,tight,and shale oil/gas)and three levels(realistic,expected,and prospective)of hydrocarbon resources of different members in the Liaohe Western Depression are evaluated.Findings suggest that the Es3 member has considerable conventional and unconventional hydrocarbon resources.This study can quantitatively characterize the hydrocarbon generation potential of source rocks with different kerogen types,and facilitate a quick and accurate assessment of hydrocarbon resources,providing strategies for future oil and gas exploration. 展开更多
关键词 Kerogen type Hydrocarbon generation potential Lacustrine source rocks Liaohe western depression
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Interdecadal variability of summer precipitation in the Three River Source Region: Influences of SST and zonal shifts of the East Asian subtropical westerly jet 被引量:1
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作者 Yumeng Liu Xianhong Meng +5 位作者 Lin Zhao S-Y.Simon Wang Lixia Zhang Zhaoguo Li Chan Wang Yingying An 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第5期47-53,共7页
Summer precipitation in the Three Rivers Source Region(TRSR)of China is vital for the headwaters of the Yellow,Yangtze,and Lancang rivers and exhibits significant interdecadal variability.This study investigates the i... Summer precipitation in the Three Rivers Source Region(TRSR)of China is vital for the headwaters of the Yellow,Yangtze,and Lancang rivers and exhibits significant interdecadal variability.This study investigates the influence of the East Asian westerly jet(EAWJ)on TRSR rainfall.A strong correlation is found between TRSR summer precipitation and the Jet Zonal Position Index(JZPI)of the EAWJ from 1961 to 2019(R=0.619,p<0.01).During periods when a positive JZPI indicates a westward shift in the EAWJ,enhanced water vapor anomalies,warmer air,and low-level convergence anomalies contribute to increased TRSR summer precipitation.Using empirical orthogonal function and regression analyses,this research identifies the influence of large-scale circulation anomalies associated with the Atlantic–Eurasian teleconnection(AEA)from the North Atlantic(NA).The interdecadal variability between the NA and central tropical Pacific(CTP)significantly affects TRSR precipitation.This influence is mediated through the AEA via a Rossby wave train extending eastward along the EAWJ,and another south of 45°N.Moreover,the NA–CTP Opposite Phase Index(OPI),which quantifies the difference between the summer mean sea surface temperatures of the NA and the CTP,is identified as a critical factor in modulating the strength of this teleconnection and influencing the zonal position of the EAWJ. 展开更多
关键词 Summer precipitation East Asian subtropical westerly jet Three River source Region Atlantic-Eurasian teleconnection
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Influence of Magmatic Intrusion on Abnormal Hydrocarbon Generation and Expulsion of Source Rock:A Case Study of the Dongying Sag,Bohai Bay Basin
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作者 LI Chuanming ZENG Jianhui +2 位作者 WANG Maoyun LONG Hui LIU Shuning 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第5期1322-1337,共16页
How gabbro affects the generation and expulsion of hydrocarbons in muddy surrounding rocks is clarified by analyzing thin section,major and trace elements,total organic carbon(TOC),pyrolysis,extracts and vitrinite ref... How gabbro affects the generation and expulsion of hydrocarbons in muddy surrounding rocks is clarified by analyzing thin section,major and trace elements,total organic carbon(TOC),pyrolysis,extracts and vitrinite reflectance data from source rocks in the Chunxi area the Dongying Sag,Bohai Bay Basin,eastern China.The results show that a magma intrusion brings copious heat to the source rocks,which promotes abnormal maturation of organic matter(OM)and rapid hydrocarbon generation.The CH_(4)and H_(2)produced by gabbro alteration play a role in hydrocarbon generation of source rocks.The hydrothermal process during magma intrusion provides many different minerals to the source rock,resulting in carbonate-rich surrounding mudstone.The carbonate and clay minerals produced by volcanic mineral alteration jointly catalyze the hydrocarbon generation of the source rock.The high-temperature baking of the intrusion results in hydrothermal pressurization and hydrocarbon generation pressurization,causing many fractures in the surrounding rock.The generated oil and gas are discharged through the fractures under diffusion and pressure.Mantle-derived CO_(2)is also conducive to the expulsion of hydrocarbons because of its strong enrichment capacity for hydrocarbons. 展开更多
关键词 igneous rock hydrocarbon generation source rock high temperature CATALYSIS EOCENE Dongying Sag
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Paleoenvironmental Characteristics of Paleogene Lacustrine Source Rocks in the Western Bozhong Sag,Bohai Bay Basin,China:Evidence from Biomarkers,Major and Trace Elements
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作者 WANG Xiang LIU Guangdi +6 位作者 SONG Zezhang SUN Mingliang WANG Xiaolin WANG Feilong CHEN Rongtao GENG Mingyang LI Yishu 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第1期220-240,共21页
The organic matter(OM)enrichment mechanisms and depositional environment characteristics of lacustrine source rocks in the western Bozhong Sag,Bohai Bay Basin in Northeast China remain controversial.To address these i... The organic matter(OM)enrichment mechanisms and depositional environment characteristics of lacustrine source rocks in the western Bozhong Sag,Bohai Bay Basin in Northeast China remain controversial.To address these issues,based on Rock-Eval pyrolysis,kerogen macerals,H/C and O/C ratios,GC-MS,major and trace elements,the Dongying Formation Member(Mbr)3(E_(3)d_(3)),the Shahejie Formation mbrs 1 and 2(E_(2)s_(1+2)),and the Shahejie Mbr 3(E_(2)s_(3))source rocks in the western Bozhong Sag were studied.The above methods were used to reveal their geochemical properties,OM origins and depositional environments,all of which indicate that E_(2)s_(1+2)and E_(2)s_(3)are excellent source rocks,and that E_(3)d_(3)is of the second good quality.E_(3)d_(3)source rocks were formed under a warm and humid climate,mainly belong to fluvial/delta facies,the E_(3)d_(3)sediments formed under weakly oxidizing and freshwater conditions.Comparatively,the depositional environments of E_(2)s_(1+2)source rocks were arid and cold climate,representing saline or freshwater lacustrine facies,and the sediments of E_(2)s_(1+2)belong to anoxic or suboxic settings with large evaporation and salinity.During the period of E_(2)s_(3),the climate became warm and humid,indicating the freshwater lacustrine facies,and E_(2)s_(3)was characterized by freshwater and abundant algae.Moreover,compared with other intervals,the OM origin of E_(3)d_(3)source rocks has noticeable terrestrial input.The OM origin of the E_(2)s_(1+2)and E_(2)s_(3)are mainly plankton and bacteria.Tectonic subsidence and climate change have affected the changes of the depositional environment in the western Bozhong Sag,thus controlling the distribution of the source rocks,the geochemical characteristics in the three intervals of lacustrine source rocks have distinct differences.Overall,these factors are effective to evaluate the paleoenvironmental characteristics of source rocks by biomarkers,major and trace elements.The established models may have positive implications for research of lacustrine source rocks in offshore areas with few drillings. 展开更多
关键词 petroleum geology source rocks depositional environments biomarkers major elements trace elements Bozhong Sag
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The Forecast Skills and Predictability Sources of Marine Heatwaves in the NUIST-CFS1.0 Hindcasts
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作者 Jing MA Haiming XU +1 位作者 Changming DONG Jing-Jia LUO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第8期1589-1600,共12页
Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast s... Using monthly observations and ensemble hindcasts of the Nanjing University of Information Science and Technology Climate Forecast System(NUIST-CFS1.0) for the period 1983–2020, this study investigates the forecast skill of marine heatwaves(MHWs) over the globe and the predictability sources of the MHWs over the tropical oceans. The MHW forecasts are demonstrated to be skillful on seasonal-annual time scales, particularly in tropical oceans. The forecast skill of the MHWs over the tropical Pacific Ocean(TPO) remains high at lead times of 1–24 months, indicating a forecast better than random chance for up to two years. The forecast skill is subject to the spring predictability barrier of El Nino-Southern Oscillation(ENSO). The forecast skills for the MHWs over the tropical Indian Ocean(TIO), tropical Atlantic Ocean(TAO), and tropical Northwest Pacific(NWP) are lower than that in the TPO. A reliable forecast at lead times of up to two years is shown over the TIO, while a shorter reliable forecast window(less than 17 months) occurs for the TAO and NWP.Additionally, the forecast skills for the TIO, TAO, and NWP are seasonally dependent. Higher skills for the TIO and TAO appear in boreal spring, while a greater skill for the NWP emerges in late summer-early autumn. Further analyses suggest that ENSO serves as a critical source of predictability for MHWs over the TIO and TAO in spring and MHWs over the NWP in summer. 展开更多
关键词 marine heatwaves NUIST-CFS1.0 hindcasts forecast skill predictability source ENSO
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Sedimentary paleoenvironment and its control on organic matter enrichment in the Mesoproterozoic hydrocarbon source rocks in the Ordos Basin,southern margin of the North China Craton
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作者 Zhi-Chen Wu Ju-Ye Shi +1 位作者 Tai-Liang Fan Ming Jiang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2257-2272,共16页
The black shale of the Mesoproterozoic Cuizhuang Formation in the Changcheng System in Yongji city,North China Craton,is a potential source rock.Understanding the organic matter enrichment mechanism is crucial for eva... The black shale of the Mesoproterozoic Cuizhuang Formation in the Changcheng System in Yongji city,North China Craton,is a potential source rock.Understanding the organic matter enrichment mechanism is crucial for evaluating source rock resources and understanding oil and gas accumulation mechanisms.In this study,we evaluated the sedimentary paleoenvironment and organic matter enrichment mechanisms of shale using thin section observations,mineral composition analysis,organic geochemistry,and elemental geochemistry.We found significant differences in the sedimentary paleoenvironment and organic matter enrichment mechanisms between the lower Cuizhuang Formation and the Beidajian Formation shale.The Cuizhuang Formation was deposited in a late-stage,restricted basin environment during the rift phase,and elemental and geochemical indicators showed that the Cuizhuang Formation was in a suboxic-anoxic water environment,that was influenced by a warm and humid paleoclimate and submarine hydrothermal activities,which promoted the accumulation of organic matter.However,the enrichment of organic matter in the Cuizhuang Formation was mainly controlled by redox conditions.The formation of suboxic-anoxic water environments may be closely related to the warm and humid paleoclimate and submarine hydrothermal activities.Warm conditions promote continental weathering and increase marine productivity,thereby consuming oxygen in the bottom water.Moreover,acidic hydrothermal activity also helps to establish an anoxic environment.Our results reveal the effects controlling various coupled mechanisms dominated by redox conditions,which may explain the development of source rocks in the Cuizhuang Formation. 展开更多
关键词 Cuizhuang formation Paleoproterozoic source rocks Marine productivity PALEOENVIRONMENTS Submarine hydrothermal activity Organic matter enrichment
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Differences and identification on multi-time hydrocarbon generation of carboniferous-permian coaly source rocks in the Huanghua Depression,Bohai Bay Basin
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作者 Jin-Jun Xu Xian-Gang Cheng +5 位作者 Shu-Nan Peng Jun-Cai Jiang Qi-Long Wu Da Lou Fu-Qi Cheng La-Mei Lin 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期765-776,共12页
Coal is a solid combustible mineral,and coal-bearing strata have important hydrocarbon generation potential and contribute to more than 12%of the global hydrocarbon resources.However,the deposition and hydrocarbon evo... Coal is a solid combustible mineral,and coal-bearing strata have important hydrocarbon generation potential and contribute to more than 12%of the global hydrocarbon resources.However,the deposition and hydrocarbon evolution process of ancient coal-bearing strata is characterized by multiple geological times,leading to obvious distinctions in their hydrocarbon generation potential,geological processes,and production,which affect the evaluation and exploration of hydrocarbon resources derived from coaly source rocks worldwide.This study aimed to identify the differences on oil-generated parent macerals and the production of oil generated from different coaly source rocks and through different oil generation processes.Integrating with the analysis of previous tectonic burial history and hydrocarbon generation history,high-temperature and high-pressure thermal simulation experiments,organic geochemistry,and organic petrology were performed on the Carboniferous-Permian(C-P)coaly source rocks in the Huanghua Depression,Bohai Bay Basin.The oil-generated parent macerals of coal's secondary oil generation process(SOGP)were mainly hydrogen-rich collotelinite,collodetrinite,sporinite,and cutinite,while the oil-generated parent macerals of tertiary oil generation process(TOGP)were the remaining small amount of hydrogen-rich collotelinite,sporinite,and cutinite,as well as dispersed soluble organic matter and unexhausted residual hydrocarbons.Compared with coal,the oil-generated parent macerals of coaly shale SOGP were mostly sporinite and cutinite.And part of hydrogen-poor vitrinite,lacking hydrocarbon-rich macerals,and macerals of the TOGP,in addition to some remaining cutinite and a small amount of crude oil and bitumen from SOGP contributed to the oil yield.The results indicated that the changes in oil yield had a good junction between SOGP and TOGP,both coal and coaly shale had higher SOGP aborted oil yield than TOGP starting yield,and coaly shale TOGP peak oil yield was lower than SOGP peak oil yield.There were significant differences in saturated hydrocarbon and aromatic parameters in coal and coaly shale.Coal SOGP was characterized by a lower Ts/Tm and C31-homohopane22S/(22S+22R)and a higher Pr/n C17compared to coal TOGP,while the aromatic parameter methyl dibenzothiophene ratio(MDR)exhibited coaly shale TOGP was higher than coaly shale SOGP than coaly TOGP than coaly SOGP,and coal trimethylnaphthalene ratio(TNR)was lower than coaly shale TNR.Thus,we established oil generation processes and discriminative plates.In this way,we distinguished the differences between oil generation parent maceral,oil generation time,and oil production of coaly source rocks,and therefore,we provided important support for the evaluation,prediction,and exploration of oil resources from global ancient coaly source rocks. 展开更多
关键词 Thermal simulation Multi-time oil generation processes Coaly source rock CARBONIFEROUS-PERMIAN Huanghua Depression
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Source and level of dietary iron influence semen quality by affecting inflammation, oxidative stress and iron utilization levels in boars
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作者 Yinghui Wu Yamei Li +8 位作者 Yueyue Miao Hongkui Wei Hefeng Luo Chunxiao Ren Yawei Zhang Juan Chen Tanghong Wei Jiyan Deng Jian Peng 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第5期2044-2058,共15页
Background Boars fed a mixed form of inorganic and organic iron in excess of the NRC recommended levels still develop anemia,which suggested that the current level and form of iron supplementation in boar diets may be... Background Boars fed a mixed form of inorganic and organic iron in excess of the NRC recommended levels still develop anemia,which suggested that the current level and form of iron supplementation in boar diets may be inappropriate.Therefore,56 healthy Topeka E line boars aged 15–21 months were randomly divided into 5 groups:basal diet supplemented with 96 mg/kg ferrous sulfate(FeSO_(4))and 54 mg/kg glycine chelated iron(Gly-Fe,control);80 mg/kg or 115 mg/kg Gly-Fe;80 mg/kg or 115 mg/kg methionine hydroxyl analogue chelated iron(MHA-Fe,from CalimetFe)for 16 weeks.The effects of dietary iron supplementation with different sources and levels on semen quality in boars were investigated.Results 1)Serum Fe and hemoglobin concentrations were not affected by reduced dietary iron levels in the 80 mg/kg or 115 mg/kg Gly-Fe and MHA-Fe groups compared with the control group(P>0.05).2)Serum interleukin-6(IL-6)and sperm malondialdehyde(MDA)levels in the 80 mg/kg or 115 mg/kg MHA-Fe groups were lower than those in the control group(P<0.05),and higher serum superoxide dismutase levels and lower MDA levels in the 115 mg/kg MHA-Fe group(P<0.05).3)Boars in the 80 mg/kg or 115 mg/kg Gly-Fe and MHA-Fe groups had lower serum hepcidin(P<0.01),ferritin(P<0.05),and transferrin receptor(P<0.01)concentrations,and boars in the 115 mg/kg MHA-Fe group had higher seminal plasma Fe concentrations compared with the control group.4)Boars in the 80 mg/kg and 115 mg/kg MHA-Fe groups had lower abnormal sperm rate and in situ oscillating sperm ratio compared to the control group at weeks 12 and/or 16 of the trial.However,the effect of Gly-Fe on improving semen quality in boars was not evident.5)Serum IL-6 level was positively correlated with hepcidin concentration(P<0.05),which in turn was significantly positively correlated with abnormal sperm rate(P<0.05).Furthermore,significant correlations were also found between indicators of iron status and oxidative stress and semen quality parameters.Conclusions Dietary supplementation with 80 mg/kg or 115 mg/kg MHA-Fe did not induce iron deficiency,but rather reduced serum inflammatory levels and hepcidin concentration,alleviated oxidative stress,increased body iron utilization,and improved semen quality in adult boars. 展开更多
关键词 Adult boars Iron level Iron source Iron status Semen quality
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Changes in Sediment Sources in the Southern Muddy Area of Weihai,China,Since the Late Pleistocene:A Record from Rare Earth Elements
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作者 ZHANG Zhichao LIU Jinqing +3 位作者 YIN Ping CAO Ke FENG Xiaokun WANG Shengyu 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第5期1221-1232,共12页
The small muddy areas developed in the southern Shandong Peninsula have attracted increasing attention from researchers because of complex changes in sediment sources driven by sea-level fluctuations and land-sea inte... The small muddy areas developed in the southern Shandong Peninsula have attracted increasing attention from researchers because of complex changes in sediment sources driven by sea-level fluctuations and land-sea interactions since the late Pleistocene.This study investigates the evolution of sediment sources and their responses to environmental changes since the late Pleistocene,using core WHZK01 collected from the nearshore muddy area in southern Weihai for rare earth element(REE)analysis.In doing so,this work highlights the changing patterns of material sources and the primary control factors.The results reveal that the sedimentary deposits in core WHZK01 exhibit distinct terrestrial characteristics.Discriminant function analysis(F_(D))and source discrimination dia-grams both suggest that the primary sources of these deposits are the Yellow River and adjacent small and medium-sized rivers,although the sources vary among different sedimentary units.Furthermore,the DU3 layer(17.82-25.10 m)displays typical riverine sedimentation,dominated by terrestrial detrital input,primarily from the local rivers,namely the Huanglei and Muzhu Rivers.The material in the DU2 layer(14.91-17.82 m)is mainly influenced by a mixture of the Qinglong and Yellow Rivers.The DU1 layer(0-14.91 m)is influenced by sea-level changes during the Holocene,with the Yellow River being the primary source,although there is also some input from local rivers.The changes in sea level during the Holocene and the input of Yellow River material carried by the coastal currents of the Yellow Sea are identified as the main controlling factors for the changes in material sources in the study area since the late Pleistocene,with small and mediumsized rivers also exerting some influence on the material sources.The above mentioned findings not only contribute to a better understanding of the source-sink systems of the Yellow River and adjacent small and mediumsized rivers but also deepen our understanding of the late Quaternary land-sea interactions in the Shandong Peninsula. 展开更多
关键词 rare earth element source identification environmental evolution muddy area southern Weihai
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