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Total Organic Carbon Enrichment and Source Rock Evaluation of the Lower Miocene Rocks Based on Well Logs: October Oil Field, Gulf of Suez-Egypt 被引量:1
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作者 Aref Lashin Saad Mogren 《International Journal of Geosciences》 2012年第4期683-695,共13页
October oil field is one of the largest hydrocarbon-bearing fields which produces oil from the sand section of the Lower Miocene Asl Formation. Two marl (Asl Marl) and shale (Hawara Formation) sections of possible sou... October oil field is one of the largest hydrocarbon-bearing fields which produces oil from the sand section of the Lower Miocene Asl Formation. Two marl (Asl Marl) and shale (Hawara Formation) sections of possible source enrichment are detected above and below this oil sand section, respectively. This study aims to identify the content of the total organic carbon based on the density log and a combination technique of the resistivity and porosity logs (Δlog R Technique). The available geochemical analyses are used to calibrate the constants of the TOC and the level of maturity (LOM) used in the (Δlog R Technique). The geochemical-based LOM is found as 9.0 and the calibrated constants of the Asl Marl and Hawara Formation are found as 11.68, 3.88 and 8.77, 2.80, respectively. Fair to good TOC% content values (0.88 to 1.85) were recorded for Asl Marl section in the majority of the studied wells, while less than 0.5% is recorded for the Hawara Formation. The lateral distribution maps show that most of the TOC% enrichments are concentrated at central and eastern parts of the study area, providing a good source for the hydrocarbons encountered in the underlying Asl Sand section. 展开更多
关键词 total organic carbon Source ROCKS WELL LOGS October Oil Field GULF of Suez
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An improved method for quantitatively measuring the sequences of total organic carbon and black carbon in marine sediment cores 被引量:1
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作者 徐小明 祝青 +3 位作者 周芊至 刘金钟 袁建平 王江海 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第1期105-113,共9页
Understanding global carbon cycle is critical to uncover the mechanisms of global warming and remediate its adverse ef fects on human activities.Organic carbon in marine sediments is an indispensable part of the globa... Understanding global carbon cycle is critical to uncover the mechanisms of global warming and remediate its adverse ef fects on human activities.Organic carbon in marine sediments is an indispensable part of the global carbon reservoir in global carbon cycling.Evaluating such a reservoir calls for quantitative studies of marine carbon burial,which closely depend on quantifying total organic carbon and black carbon in marine sediment cores and subsequently on obtaining their high-resolution temporal sequences.However,the conventional methods for detecting the contents of total organic carbon or black carbon cannot resolve the following specific difficulties,i.e.,(1)a very limited amount of each subsample versus the diverse analytical items,(2) a low and fluctuating recovery rate of total organic carbon or black carbon versus the reproducibility of carbon data,and(3)a large number of subsamples versus the rapid batch measurements.In this work,(i)adopting the customized disposable ceramic crucibles with the microporecontrolled ability,(ii)developing self-made or customized facilities for the procedures of acidification and chemothermal oxidization,and(iii)optimizing procedures and carbon-sulfur analyzer,we have built a novel Wang-Xu-Yuan method(the WXY method)for measuring the contents of total organic carbon or black carbon in marine sediment cores,which includes the procedures of pretreatment,weighing,acidification,chemothermal oxidation and quantification;and can fully meet the requirements of establishing their highresolution temporal sequences,whatever in the recovery,experimental efficiency,accuracy and reliability of the measurements,and homogeneity of samples.In particular,the usage of disposable ceramic crucibles leads to evidently simplify the experimental scenario,which further results in the very high recovery rates for total organic carbon and black carbon.This new technique may provide a significant support for revealing the mechanism of carbon burial and evaluating the capacity of marine carbon accumulation and sequestration. 展开更多
关键词 total organic carbon black carbon marine sediment cores chemothermal oxidation disposable ceramic crucible
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Clean Coal &High Carbon Efficiency Energy Engineering
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作者 Stefan Petters Kalvin Tse 《Journal of Power and Energy Engineering》 2015年第4期348-355,共8页
Today we live in a world of Hydrocarbon Energy Carriers, where Carbon is always used as a Carrier for Hydrogen 1) Biomass (CH1.44O0.66 or C6H12O6);2) Natural Gas [NG] (CH4);3) Water Gas [C+H2O];4) Gasoline (C6H12, C7H... Today we live in a world of Hydrocarbon Energy Carriers, where Carbon is always used as a Carrier for Hydrogen 1) Biomass (CH1.44O0.66 or C6H12O6);2) Natural Gas [NG] (CH4);3) Water Gas [C+H2O];4) Gasoline (C6H12, C7H18, C8H18, etc.);5) Kerosene (C17H36, C18H38, C19H40, C20H42, C21H44, C22H46, etc.) and;6) Crude Oil. The Carbon aggregates are all storable and have worthwhile, logistically manageable energy densities. But whenever recovering Energy from the Carbon molarities, CO2 gets emitted into the atmosphere, while separate use of Hydrogen Energy contents carried by the Carbon moieties would just generate water vapor. Hydrogen is also the most important intermediary in Refineries, hydrogenating lower grade Hydrocarbons into higher potencies, or for removing Sulfur by the formation of Hydrogen Sulfur, that can be dissociated after its segregation from the Hydrocarbon products. But most of the internal Hydrogen yields in Refineries today is used for onsite production of Ammonia as a basis for Energy fertilizers in high performance agriculture. Because Hydrogen is awkward to store and transport, most of it is currently used captive within large size centralized plants as a reactant for producing Hydrocarbon energy carriers, using the Carbon as a carrier for the Hydrogen moieties, to then be distributed over big enough areas for consumption of the such large scale plants’ volumes. With recently proven achievements of Hydrogen production from excess Wind & Solar Power by electrolysis, Hydrogen could become available in abundant quantities, to be distributed locally within the coverage area of the transmission grid such Wind & Solar installations are feeding into. In combination with Carbon as a reactant such abundant Hydrogen could also be synthesized into Hydrocarbon Energy Carriers and substitute fossil commodities. 展开更多
关键词 Atmospheric carbon carbon EFFICIENCY carbon Metabolism carbon Re-Use Chemical ENERGY Content Controlled Microbial Composting ENERGY Carriers Fossil Substitute Commodities INTERMEDIARIES Heating Value Hybrid Power Plant Hydrocarbon Hydrogen organic Waste VALORIZATION Photosynthesis Productivity REFINERIES
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Microbial Biomass Carbon and Total Organic Carbon of Soils as Affected by Rubber Cultivation 被引量:36
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作者 ZHANG Hua and ZHANG Gan-LinInstitute of Soil Science, the Chinese Academy of Sciences, P. O. Box 821, Nanjing 210008 《Pedosphere》 SCIE CAS CSCD 2003年第4期353-357,共5页
Soil samples were collected from different rubber fields in twenty-five plotsselected randomly in the Experimental Farm of the Chinese Academy of Tropical Agriculture Scienceslocated in Hainan, China, to analyse the e... Soil samples were collected from different rubber fields in twenty-five plotsselected randomly in the Experimental Farm of the Chinese Academy of Tropical Agriculture Scienceslocated in Hainan, China, to analyse the ecological effect of rubber cultivation. The results showedthat in the tropical rubber farm, soil microbial biomass C (MBC) and total organic C (TOC) wererelatively low in the content but highly correlated with each other. After rubber tapping, soil MBCof mature rubber fields decreased significantly, by 55.5 percent. compared with immature rubberfields. Soil TOC also decreased but the difference was not significant. Ratios of MBC to TOCdecreased significantly. The decreasing trend of MBC stopped at about ten years of rubbercultivation. After this period, soil MBC increased relatively while soil TOC still kept indecreasing. Soil MBC changes could be measured to predict the tendency of soil organic matterchanges due to management practices in a tropical rubber farm several years before the changes insoil TOC become detectable. 展开更多
关键词 microbial biomass carbon organic C RUBBER tropical soils
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Effects of Tillage Methods on Soil Organic Carbon and Total Nitrogen Content in the Loess Plateau 被引量:2
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作者 Tingting MENG 《Asian Agricultural Research》 2020年第2期25-27,共3页
In order to determine whether long-term no-tillage operation in the loess plateau threatens soil fertility and crop yield,a suitable high-yield and efficient tillage technology system was established.In the Changwu lo... In order to determine whether long-term no-tillage operation in the loess plateau threatens soil fertility and crop yield,a suitable high-yield and efficient tillage technology system was established.In the Changwu loess plateau agri-Gecological experiment station of the Northwest A&F University of Changwu County,Shaanxi Province,the no-tillage experimental field for three consecutive years was selected.In September 2015,no-tillage,tillage,and rotary tillage were carried out before winter wheat was sowed.After the harvest of winter wheat in2016,soil organic carbon,total nitrogen and wheat yield in 0-30 cm soil layers under different tillage methods were analyzed.The results showed that the soil organic carbon and total nitrogen contents in the 0-30 cm soil layer decreased along the profile under the three tillage methods.In this study,the soil organic carbon and total nitrogen content in the 0-10 cm soil layer under different tillage methods were no-tillage>rotary tillage>tillage,the actual yield of winter yield in one hectare was tillage>rotary tillage>no-tillage,and there was significant difference in the actual yield of winter wheat only between the no-tillage and tillage. 展开更多
关键词 LOESS PLATEAU Different TILLAGE methods organic carbon total nitrogen WHEAT yield
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Characteristics of Soil Organic Carbon, Total Nitrogen, and C/N Ratio in Chinese Apple Orchards 被引量:7
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作者 Shunfeng Ge Haigang Xu +1 位作者 Mengmeng Ji Yuanmao Jiang 《Open Journal of Soil Science》 2013年第5期213-217,共5页
Soil organic carbon and nitrogen are used as indexes of soil quality assessment and sustainable land use management. At the same time, soil C/N ratio is a sensitive indicator of soil quality and for assessing the carb... Soil organic carbon and nitrogen are used as indexes of soil quality assessment and sustainable land use management. At the same time, soil C/N ratio is a sensitive indicator of soil quality and for assessing the carbon and nitrogen nutrition balance of soils. We studied the characteristics of soil organic carbon and total nitrogen by investigating a large number of apple orchards in major apple production areas in China. High apple orchard soil organic carbon content was observed in the provinces of Heilongjiang, Xinjiang, and Yunnan, whereas low content was found in the provinces of Shandong, Henan, Hebei, and Shaanxi, with the values ranging between 6.44 and 7.76 g·kg-1. Similar to soil organic carbon, soil total nitrogen content also exhibited obvious differences in the 12 major apple producing provinces. Shandong apple orchard soil had the highest total nitrogen content (1.26 g·kg-1), followed by Beijing (1.23 g·kg-1). No significant difference was noted between these two regions, but their total nitrogen content was significantly higher than the other nine provinces, excluding Yunnan. The soil total nitrogen content for Xinjiang, Heilongjiang, Hebei, Henan, and Gansu was between 0.87 and 1.03 g·kg-1, which was significantly lower than that in Shandong and Beijing, but significantly higher than that in Liaoning, Shanxi, and Shaanxi. Six provinces exhibited apple orchard soil C/N ratio higher than 10, including Heilongjiang (15.42), Xinjiang (13.38), Ningxia (14.45), Liaoning (12.24), Yunnan (11.03), and Gansu (10.63). The soil C/N ratio was below 10 in the remaining six provinces, in which the highest was found in Shaanxi (9.47), followed by Beijing (8.98), Henan (7.99), and Shanxi (7.62), and the lowest was found in Hebei (6.80) and Shandong (6.05). Therefore, the improvement of soil organic carbon should be given more attention to increase the steady growth of soil C/N ratio. 展开更多
关键词 CHINESE APPLE ORCHARD Soil organic carbon total Nitrogen C/N Ratio
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Lower limit of thermal maturity for the carbonization of organic matter in marine shale and its exploration risk 被引量:4
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作者 WANG Yuman LI Xinjing +8 位作者 CHEN Bo WU Wei DONG Dazhong ZHANG Jian HAN Jing MA Jie DAI Bing WANG Hao JIANG Shan 《Petroleum Exploration and Development》 2018年第3期402-411,共10页
Based on the drilling data of the Silurian Longmaxi Formation in the Sichuan Basin and periphery, SW China, the Ro lower limits and essential features of the carbonization of organic matter in over-high maturity marin... Based on the drilling data of the Silurian Longmaxi Formation in the Sichuan Basin and periphery, SW China, the Ro lower limits and essential features of the carbonization of organic matter in over-high maturity marine shale were examined using laser Raman, electrical and physical property characterization techniques. Three preliminary conclusions are drawn:(1) The lower limit of Ro for the carbonization of Type I-II1 organic matter in marine shale is 3.5%; when the Ro is less than 3.4%, carbonization of organic matter won't happen in general; when the Ro ranges from 3.4% to 3.5%, non-carbonization and weak carbonization of organic matter may coexist; when the Ro is higher than 3.5%, the carbonization of organic matter is highly likely to take place.(2) Organic-rich shale entering carbonization phase have three basic characteristics: log resistivity curve showing a general "slender neck" with low-ultralow resistance response, Raman spectra showing a higher graphite peak, and poor physical property(with matrix porosity of only less than 1/2 of the normal level).(3) The quality damage of shale reservoir caused by the carbonization of organic matter is almost fatal, which primarily manifests in depletion of hydrocarbon generation capacity, reduction or disappearance of organic pores and intercrystalline pores of clay minerals, and drop of adsorption capacity to natural gas. Therefore, the lower limit of Ro for the carbonization of Type I-II1 organic matter should be regarded as the theoretically impassable red line of shale gas exploration in the ancient marine shale formations. The organic-rich shale with low-ultralow resistance should be evaluated effectively in area selection to exclude the high risk areas caused by the carbonization of organic matter. The target organic-rich shale layers with low-ultralow resistance drilled during exploration and development should be evaluated on carbonization level of organic matter, and the deployment plan should be adjusted according to the evaluation results in time. 展开更多
关键词 Lower SILURIAN Longmaxi Formation MARINE SHALE thermal maturity organic matter carbonIZATION resistivity LOGGING exploration risk
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Measurement of the neutron total cross section of carbon at the Back-n white neutron beam of CSNS 被引量:7
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作者 Xing-Yan Liu Yi-Wei Yang +79 位作者 Rong Liu Jie Wen Zhong-Wei Wen Zi-Jie Han Zhi-Zhou Ren Qi An Huai-Yong Bai Jie Bao Ping Cao Qi-Ping Chen Yong-Hao Chen Pin-Jing Cheng Zeng-Qi Cui Rui-Rui Fan Chang-Qing Feng Min-Hao Gu Feng-Qin Guo Chang-Cai Han Guo-Zhu He Yong-Cheng He Yue-Feng He Han-Xiong Huang Wei-Ling Huang Xi-Ru Huang Xiao-Lu Ji Xu-Yang Ji Hao-Yu Jiang Wei Jiang Han-Tao Jing Ling Kang Ming-Tao Kang Bo Li Lun Li Qiang Li Xiao Li Yang Li Yang Li Shu-Bin Liu Guang-Yuan Luan Ying-Lin Ma Chang-Jun Ning Bin-Bin Qi Jie Ren Xi-Chao Ruan Zhao-Hui Song Hong Sun Xiao-Yang Sun Zhi-Jia Sun Zhi-Xin Tan Hong-Qing Tang Jing-Yu Tang Peng-Cheng Wang Qi Wang Tao-Feng Wang Yan-Feng Wang Zhao-Hui Wang Zheng Wang Qing-Biao Wu Xiao-Guang Wu Xuan Wu Li-Kun Xie Han Yi Li Yu Tao Yu Yong-Ji Yu Guo-Hui Zhang Jing Zhang Lin-Hao Zhang Li-Ying Zhang Qing-Min Zhang Qi-Wei Zhang Xian-Peng Zhang Yu-Liang Zhang Zhi-Yong Zhang Ying-Tan Zhao Liang Zhou Zu-Ying Zhou Dan-Yang Zhu Ke-Jun Zhu Peng Zhu 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第9期73-82,共10页
To verify the performance of the neutron total cross-sectional spectrometer, the neutron total cross section of carbon is initially measured in the energy range of 1 eV to 20 MeV using the time-of-flight method. The m... To verify the performance of the neutron total cross-sectional spectrometer, the neutron total cross section of carbon is initially measured in the energy range of 1 eV to 20 MeV using the time-of-flight method. The measurement is performed at the Back-n white neutron source with a 76-m time-of-flight path using the China Spallation Neutron Source. A multilayer fast fission chamber with 235U and 238U is employed as the neutron detector. The diameter and thickness of the natural graphite sample are 70 mm and 40 mm, respectively. Signal waveforms are collected using a data acquisition system. Off-line data processing was used to obtain the neutron time-of-flight spectra and transmissions. The uncertainty of the counting statistics is generally approximately 3% for each bin in the energy range of 1–20 MeV. It is determined that the results for the neutron total cross section of carbon obtained using ^235U cells are in good agreement with the results obtained using 238U cells within limits of statistical uncertainty. Moreover, the measured total cross sections show good agreement with the broadening evaluated data. 展开更多
关键词 CSNS Back-n WHITE NEUTRON source NTOX NEUTRON total cross section carbon Multilayer fast FISSION chamber
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Centennial-scale records of total organic carbon in sediment cores from the South Yellow Sea, China 被引量:1
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作者 祝青 林佳 +4 位作者 洪跃辉 袁丽蓉 刘金钟 徐小明 王江海 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2018年第1期128-138,共11页
Global carbon cycling is a significant factor that controls climate change.The centennial-scale variations in total organic carbon(TOC)contents and its sources in marginal sea sediments may reflect the influence of hu... Global carbon cycling is a significant factor that controls climate change.The centennial-scale variations in total organic carbon(TOC)contents and its sources in marginal sea sediments may reflect the influence of human activities on global climate change.In this study,two fine-grained sediment cores from the Yellow Sea Cold Water Mass of the South Yellow Sea were used to systematically determine TOC contents and stable carbon isotope ratios.These results were combined with previous data of black carbon and (210)~Pb dating from which we reconstructed the centennial-scale initial sequences of TOC,terrigenous TOC(TOC_(ter))and marine autogenous TOC(TOC_(mar))after selecting suitable models to correct the measured TOC(TOC_(cor)).These sequences showed that the TOC_(ter) decreased with time in the both cores while the TOC_(mar) increased,particularly the rapid growth in core H43 since the late 1960s.According to the correlation between the Huanghe(Yellow)River discharge and the TOC_(cor),TOC_(ter),or TOC_(mar),we found that the TOC_(ter) in the two cores mainly derived from the Huanghe River and was transported by it,and that higher Huanghe River discharge could strengthen the decomposition of TOC_(mar).The newly obtained initial TOC sequences provide important insights into the interaction between human activities and natural processes. 展开更多
关键词 organic carbon Middelburgs model Yellow Sea
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Application o f 210 Pb, Carbon and Nitrogen Isotope in Tracing of Changes and Burial Effect of Endogenous and Terrigenous Organic Matter in the Bering Sea over the Past 100 Years
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作者 Zhang Haisheng Chen Jianfang +4 位作者 Han Zhengbing Han Xibin Xu Xudan Fan Gaojing Lu Bing 《Meteorological and Environmental Research》 CAS 2017年第5期111-117,共7页
By using the multi-tube sediment samples collected from NB01 station in the Bering Sea during the period of the fourth Chinese Arctic research expedition in 2010,as well as the dating technique of radioisotope ^(210)P... By using the multi-tube sediment samples collected from NB01 station in the Bering Sea during the period of the fourth Chinese Arctic research expedition in 2010,as well as the dating technique of radioisotope ^(210)Pb in sedimentary strata,based on the exponential decay trend of ^(210)Pb exwith the column sample depth,relative stable modern sedimentary environment in the investigation area was reflected. The results show that the deposition rate of modern marine sediment S was 0. 27 cm/a,and correlation coefficient R was 0. 96( n = 17),while time span was 107 a(1903-2010). Meanwhile,carbon,nitrogen and isotopes were used to trace the sources of materials in the Bering Sea. It is found that the content of organic carbon and nitrogen in the column samples from NB01 station in the Bering Sea was 1. 18%-1. 80% and 0. 16%-0. 28% respectively,and C/N ratio ranged from 5. 13 to 8. 31. Total organic carbon( TOC) and total organic nitrogen( TON) were preserved well in sedimentary strata and had good consistency,showing that sources of organic matter were consistent. Moreover,their changes positively correlated with^(210)Pb. Organic carbon isotope( δ13 C) ranged from-22. 45‰ to-21. 82‰,and its changing trend was similar to that of C/N ratio; organic nitrogen isotope(δ15 N) varied from 7. 53‰ to 8. 54‰,indicating that organic matter was mainly from remaining marine organisms after being decomposed,into which a certain quantity of terrigenous materials were mixed. In the 100 years,the overall trend of terrigenous materials became increasingly obvious,showing that the input and burial of organic carbon from seas and land in the Bering Sea were changing. According to the burial rate of surface sediment and content of organic carbon,the apparent burial flux of sedimentary organic carbon in the column sample from NB01 station in the Bering Sea was estimated,about 1 450 mmol C/( m^2·a). It is suggested that the high burial flux of sedimentary organic carbon in the regions was mainly related to the high primary productivity of the water body,the high output efficiency of organic carbon in the photic zone,favorable preservation and metabolic mechanism of organic matter,and high deposition rate. 展开更多
关键词 The ARCTIC The BERING Sea 210Pb Deposition rate organic carbon and nitrogen ISOTOPE Sources of materials
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Blocking Behavior of Organic Solid Phase in the Carbon Dioxide Multiphase and Multicomponent Displacement Process
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作者 Peng Yu 《Journal of Power and Energy Engineering》 2019年第1期183-189,共7页
Better dealing with carbon issues can support the management of current greenhouse gas emissions while achieving energy economic diversification and energy security. Carbon dioxide displacement has become the most ack... Better dealing with carbon issues can support the management of current greenhouse gas emissions while achieving energy economic diversification and energy security. Carbon dioxide displacement has become the most acknowledged and practical method in enhanced oil recovery system. This is because of its oil sweep efficiency and ability to reduce the level of greenhouse gas emission. Nevertheless, it would lead to the organic solid phase deposition, which causes the changes of the wettability and the damages of wellbores and reservoirs. In this study, we used slim tube test and component test to research the dynamic characteristics of displacement process. In addition, the mechanism of porous media blockage was also investigated. Results show that when the displacement pressure closed to the minimum miscibility pressure, reservoir blockage in pore throat could happen. Component test characterizes that during near miscible displacement process, the components of oil sample varied obviously, the variation range of peak component carbon marks fluctuated strongly. Crude oil component differentiation could happen after carbon dioxide fully contacted with oil. Besides, the rapid extraction mechanism of aromatic hydrocarbons played a significant role in this process under such condition. The reason is that the solubility of saturated hydrocarbons to asphaltene and non-hydrocarbons is obviously weaker than aromatic hydrocarbons. Controlling the pressure is considered as an important link to prevent the occurrence of blocking in the carbon dioxide multiphase and multicomponent displacement process. 展开更多
关键词 BLOCKING BEHAVIOR organic Solid Phase carbon Dioxide Displacement MULTIPHASE and MULTICOMPONENT Near Minimum MISCIBLE Pressure
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Assessment of soil quality using soil organic carbon and total nitrogen and microbial properties in tropical agroecosystems 被引量:1
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作者 Maruf Kajogbola Adebayo Adeboye Abdullahi Bala +3 位作者 Akim Oserhien Osunde Anthony Ozoemenam Uzoma Ayo Joshua Odofin Baba Abubakar Lawal 《Agricultural Sciences》 2011年第1期34-40,共7页
Assessment of soil quality is an invaluable tool in determining the sustainability and environmental impact of agricultural ecosystems. The study was conducted to assess the quality of the soils under arable cultivati... Assessment of soil quality is an invaluable tool in determining the sustainability and environmental impact of agricultural ecosystems. The study was conducted to assess the quality of the soils under arable cultivation, locally irri-gated and non-irrigated, forestry plantations of teak (Tectona grandis Lin.) and gmelina (Gme- lina arborea Roxb.), and cashew (Anacardium occidentale Lin.) plantation agro ecosystems using soil organic carbon (SOC), soil total ni-trogen (STN) and soil microbial biomass C (SMBC) and N (SMBN) at Minna in the southern Guinea savanna of Nigeria. Soil samples were collected from soil depths of 0-5 cm and 5-10 cm in all the agro ecosystems and analyzed for physical, chemical and biological properties. All the agro ecosystems had similar loamy soil texture at both depths. The soils have high fer-tility status in terms of available phosphorus and exchangeable calcium, magnesium and po- tassium. The irrigated arable land had significantly (P 6.6 suggesting fungal domination in all the agroecosystems. The forestry plantation soils had higher SMBC and SMBN as a per-centage of SOC and STN respectively than the cultivated arable land soils. Burning for clearing vegetation and poor stocking of forestry planta-tions may impair the quality of the soil. The study suggests that the locally irrigated agro- ecosystem soil seems to be of better quality than the other agroecosystem soils. 展开更多
关键词 AGROECOSYSTEMS MICROBIAL BIOMASS SOIL organic carbon SOIL total Nitrogen TROPICAL
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Substitution of chemical fertilizer by Chinese milk vetch improves the sustainability of yield and accumulation of soil organic carbon in a double-rice cropping system 被引量:16
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作者 ZHOU Xing LU Yan-hong +5 位作者 LIAO Yu-lin ZHU Qi-dong CHENG Hui-dan NIE Xin CAO Wei-dong NIE Jun 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第10期2381-2392,共12页
The double-rice cropping system is a very important intensive cropping system for food security in China. There have been few studies of the sustainability of yield and accumulation of soil organic carbon (SOC) in the... The double-rice cropping system is a very important intensive cropping system for food security in China. There have been few studies of the sustainability of yield and accumulation of soil organic carbon (SOC) in the double-rice cropping system following a partial substitution of chemical fertilizer by Chinese milk vetch (Mv). We conducted a 10-year (2008–2017) field experiment in Nan County, South-Central China, to examine the double-rice productivity and SOC accumulation in a paddy soil in response to different fertilization levels and Mv application (22.5 Mg ha^–1). Fertilizer and Mv were applied both individually and in combination (sole chemical fertilizers, Mv plus 100, 80, 60, 40, and 0% of the recommended dose of chemical fertilizers, labeled as F100, MF100, MF80, MF60, MF40, and MF0, respectively). It was found that the grain yields of double-rice crop in treatments receiving Mv were reduced when the dose of chemical fertilizer was reduced, while the change in SOC stock displayed a double peak curve. The MF100 produced the highest double-rice yield and SOC stock, with the value higher by 13.5 and 26.8% than that in the F100. However, the grain yields increased in the MF80 (by 8.4% compared to the F100), while the SOC stock only increased by 8.4%. Analogous to the change of grain yield, the sustainable yield index (SYI) of double rice were improved significantly in the MF100 and MF80 compared to the F100, while there was a slight increase in the MF60 and MF40. After a certain amount of Mv input (22.5 Mg ha^–1), the carbon sequestration rate was affected by the nutrient input due to the stimulation of microbial biomass. Compared with the MF0, the MF100 and MF40 resulted in a dramatically higher carbon sequestration rate (with the value higher by 71.6 and 70.1%), whereas the MF80 induced a lower carbon sequestration rate with the value lower by 70.1% compared to the MF0. Based on the above results we suggested that Mv could partially replace chemical fertilizers (e.g., 40–60%) to improve or maintain the productivity and sustainability of the double-rice cropping system in South-Central China. 展开更多
关键词 CHINESE MILK VETCH fertilizer application levels rice YIELD soil organic carbon double-rice cropping system
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Characteristics of soil organic carbon mineralization and influence factor analysis of natural Larix olgensis forest at different ages 被引量:6
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作者 Ling Liu Haiyan Wang Wei Dai 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第4期1495-1506,共12页
Soil organic carbon(SOC)mineralization is closely related to carbon source or sink of terrestrial ecosystem.Natural stands of Larix olgensis on the Jincang forest farm,Jilin Province were selected to investigate the d... Soil organic carbon(SOC)mineralization is closely related to carbon source or sink of terrestrial ecosystem.Natural stands of Larix olgensis on the Jincang forest farm,Jilin Province were selected to investigate the dynamics of SOC mineralization and its correlations with other soil properties in a young forest and mid-aged forest at soil depths of 0–10,>10–20,>20–40 and>40–60 cm.The results showed that compared with a mid-aged forest,the SOC stock in the young forest was 32%higher.Potentially mineralizable soil carbon(C0)in the young forest was 1.1–2.5 g kg^-1,accounting for 5.5–8.1%of total SOC during the 105 days incubation period and 0.3–1.5 g kg^-1 in the mid-aged forest at different soil depths,occupying 2.8–3.4%of total SOC.There was a significant difference in C0 among the soil depths.The dynamics of the SOC mineralization was a good fit to a three-pool(labile,intermediate and stable)carbon decomposition kinetic model.The SOC decomposition rate for different stand ages and different soil depths reached high levels for the first 15 days.Correlation analysis revealed that the C0 was significantly positively related with SOC content,soil total N(TN)and readily available K(AK)concentration.The labile soil carbon pool was significantly related to SOC and TN concentration,and significantly negatively correlated with soil bulk density.The intermediate carbon pool was positively associated with TN and AK.The stable carbon pool had negative correlations with SOC,TN and AK. 展开更多
关键词 LARIX olgensis SOIL organic carbon MINERALIZATION SOIL physical and chemical properties carbon POOLS FOREST age
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Influence of the biological carbon pump effect on the sources and deposition of organic matter in Fuxian Lake, a deep oligotrophic lake in southwest China 被引量:2
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作者 Haibo He Zaihua Liu +5 位作者 Chongying Chen Yu Wei Qian Bao Hailong Sun Yundi Hu Hao Yan 《Acta Geochimica》 EI CAS CSCD 2019年第5期613-626,共14页
Biological carbon pumping(BCP)is a key process in which dissolved inorganic carbon in terrestrial aquatic ecosystems is utilized by aquatic autotrophs for photosynthesis and transformed into autochthonous organic matt... Biological carbon pumping(BCP)is a key process in which dissolved inorganic carbon in terrestrial aquatic ecosystems is utilized by aquatic autotrophs for photosynthesis and transformed into autochthonous organic matter(AOC).However,the mechanisms underlying BCP and the amount of generated AOC deposited effectively,are still poorly understood.Therefore,we conducted a systematic study combining modern hydrochemical monitoring and a sediment trap experiment in Fuxian Lake(Yunnan,SW China),the second-deepest plateau,oligotrophic freshwater lake in China.Temperature,pH,EC(electrical conductivity),DO(dissolved O2),[HCO3^-],[Ca^2+],SIc,partial CO2(pCO2)pressure,and carbon isotopic compositions of HCO3^-(δ^13CDIc)in water from Fuxian Lake all displayed distinct seasonal and vertical variations.This was especially apparent in an inverse correlation between pCO2 and DO,indicating that variations of hydrochemistry in the lake water were mainly controlled by the metabolism of the aquatic phototrophs.Furthermore,the lowest C/N ratios and highestδ^13Corg were recorded in the trap sediments.Analyses of the C/N ratio demonstrated that the proportions of AOC ranged from 30%to 100%of all OC,indicating that AOC was an important contributor to sedimentary organic matter(OC).It was calculated that the AOC flux in Fuxian Lake was 20.43 t C km^-2 in 2017.Therefore,AOC produced by carbonate weathering and aquatic photosynthesis could potentially be a significant carbon sink and may have an important contribution to solving the lack of carbon sinks in the global carbon cycle. 展开更多
关键词 carbonate weathering Hydrochemical variation BIOLOGICAL carbon PUMP EFFECT Sediment trap AUTOCHTHONOUS organic carbon carbon sink
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Analysis of the Law of Organic Solid Phase Precipitation and Deposition during Carbon Dioxide Displacement Process
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作者 Peng Yu 《Journal of Geoscience and Environment Protection》 2019年第1期118-122,共5页
Carbon Capture, Utilization and Storage (CCUS) has been regarded as an indispensable, strategic and pressing technology to reduce anthropogenic carbon dioxide emissions, and mitigate the severe consequences of climate... Carbon Capture, Utilization and Storage (CCUS) has been regarded as an indispensable, strategic and pressing technology to reduce anthropogenic carbon dioxide emissions, and mitigate the severe consequences of climate change. Its utilization and storage play important roles in this system and they can be applied for oceanic and underground geological sequestration especially for the oil gas reservoir that needs to improve recovery. For the carbon dioxide flooding process, the crude oil displacement generally shows a better performance with the increase of the pressure. However, carbon disposal is always complex. It could encounter organic solid phase precipitation and deposition in near miscibility environment. The law of multiphase and multicomponent diversification in the whole processes is still poorly understood. We thus used the method of slim tube to get dynamic data during the process. Indeed, the interval of near minimum miscibility pressure was determined. Analysis results of injectivity index and productivity index show that the reservoir blockage primarily appears as the displacement pressure is higher than the near minimum miscibility lower limit pressure and plays an important role in the production capacity. Extortionate or low pressure is not conducive to carbon dioxide displacement. 展开更多
关键词 organic Solid Phase Precipitaion and DEPOSITION carbon Dioxide DISPLACEMENT BLOCKAGE Near Minimum MISCIBILITY Pressure
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Effects of organic carbon consumption on denitrifier community composition and diversity along dissolved oxygen vertical profiles in lake sediment surface 被引量:2
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作者 HONG Pei GONG Shihao +7 位作者 WANG Chunbo SHU Yilin WU Xingqiang TIAN Cuicui Oscar Omondi DONDE CAI Pei WU Huaming XIAO Bangding 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2020年第3期733-744,共12页
At present,the understanding of the dynamics of denitrifiers at different dissolved oxygen(DO)layers under organic carbon consumption within the surface sediments remains inadequate.In this study,high-throughput seque... At present,the understanding of the dynamics of denitrifiers at different dissolved oxygen(DO)layers under organic carbon consumption within the surface sediments remains inadequate.In this study,high-throughput sequencing and quantitative PCR targeting nirS gene were used to analyze the denitrifier abundance dynamics,community composition,and structure for aerobic(DO 0.5-6.9 mg/L),hypoxic-anoxic(DO 0-0.5 mg/L),and anoxic(DO 0 mg/L)layers in surface sediments under organic carbon consumption.Based on the analysis of nirS gene abundance,the values of denitrifying bacteria decreased with organic carbon consumption at different DO layers.When the bacterial species abundance at the genus level were compared between the high-carbon and low-carbon sediments,there was significant increase in 6 out of 36,7 out of 36 and 6 out of 36 genera respectively for the aerobic,hypoxic-anoxic and anoxic layers.On the other hand,14 out of 36,9 out of 36 and 15 out of 36 genera showed significant decrease in bacterial species abundance respectively for the aerobic,hypoxic-anoxic and anoxic layers.Additionally,14 out of 36,20 out of 36,and 15 out of 36 genera had no change in bacterial species abundance respectively for the aerobic,hypoxic-anoxic,and anoxic layers.This indicates that the carbon utilization ability of different denitrifiers on each DO layers was generally different from each other.Diversity of denitrifying bacteria also presented significant differences in different DO layers between the high-and low-carbon content sediment layers.Moreover,under the high-carbon and low-carbon content,the abundance of nirS gene showed a high peak within the hypoxic-anoxic regions,suggesting that this region might be the main distribution area for the denitrifying bacteria within the surface sediments.Furthermore,community of unique denitrifiers occurred in different DO layers and the adaptive changes of the denitrifier community followed the organic carbon consumption. 展开更多
关键词 EUTROPHIC FRESHWATER lake SURFACE sediments dissolved oxygen PROFI les denitrifier organic carbon CONSUMPTION
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坡耕地土壤有机碳再分布特征及其迁移累积平衡 被引量:8
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作者 方华军 杨学明 +1 位作者 张晓平 梁爱珍 《核农学报》 CAS CSCD 北大核心 2005年第3期202-207,共6页
利用137Cs和飞灰示踪技术,研究坡耕地黑土近50年和近100年来土壤再分布过程,计算坡耕地土壤有机碳(SOC)迁移和累积平衡。结果表明:利用SOC的深度分布特征鉴定坡脚和坡足原始埋藏土壤的表面分别位于地表下70和80cm,其埋藏层的SOC含量分... 利用137Cs和飞灰示踪技术,研究坡耕地黑土近50年和近100年来土壤再分布过程,计算坡耕地土壤有机碳(SOC)迁移和累积平衡。结果表明:利用SOC的深度分布特征鉴定坡脚和坡足原始埋藏土壤的表面分别位于地表下70和80cm,其埋藏层的SOC含量分别比与其接壤的上覆土层SOC含量高5.2和0.4gkg。坡顶、坡肩和坡背均遭受侵蚀,年平均侵蚀的土壤厚度为0.2、5.0和2.2mmyr。坡脚和坡足部位飞灰到达的深度分别为70和80cm,与埋藏层表面相吻合。坡脚飞灰出现于埋藏A层之中,表明沉积区在蒸汽机车开始使用前已被开垦为农田(或已有侵蚀和堆积发生)。根据137Cs和飞灰分布深度构建了不同年代的坡型,结果表明侵蚀部位剥蚀的土壤多堆积在坡脚和坡足,且搬运的土壤物质先累积于坡脚,随着景观坡度变缓,土壤累积逐渐向坡足过渡。研究区(1m宽)坡顶、坡肩和坡背近百年来由于土壤侵蚀共失去683kgSOC,其中60%(418kgSOC)沉积在坡脚和坡足等低洼部位,其中有257kgSOC是近50年累积的。 展开更多
关键词 ^137CS SOC 100 50 使
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The effect of the feedback cycle between the soil organic carbon and the soil hydrologic and thermal dynamics
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作者 Kensuke Mori Takeshi Ise +2 位作者 Miyuki Kondo Yongwon Kim Hiroyuki Enomoto 《Open Journal of Ecology》 2012年第2期90-95,共6页
Biogeochemical feedback processes between soil organic carbon (SOC) in high-latitude organic soils and climate change is of great concern for projecting future climate. More accurate models of the SOC stock and its dy... Biogeochemical feedback processes between soil organic carbon (SOC) in high-latitude organic soils and climate change is of great concern for projecting future climate. More accurate models of the SOC stock and its dynamics in organic soil are of increasing importance. As a first step toward creating a soil model that accurately represents SOC dynamics, we have created the Physical and Biogeochemical Soil Dynamics Model (PB-SDM) that couples a land surface model with a SOC dynamics model to simulate the feedback cycle of SOC accumulation and thermal hydrological dynamics of high-latitude soils. The model successfully simulated soil temperatures for observed data from a boreal forest near Fairbanks, and 2000 year simulations indicated that the effect of the feedback cycle of SOC accumulation on soil thickness would result in a significant differences in the amount of SOC. 展开更多
关键词 SOIL organic carbon High-Latitude SOIL SOIL Hydrology SOIL Thermal Regime Land Surface MODEL organic carbon Decomposition MODEL FEEDBACK CYCLE
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Effects of Conservation Tillage on Total and Aggregated Soil Organic Carbon in the Andes
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作者 Marcela Quintero Nicholas B. Comerford 《Open Journal of Soil Science》 2013年第8期361-373,共13页
Many Andisols of the Andes have been disturbed by traditional potato-based rotation agriculture disrupting soil structure, water retention capacity and organic matter content. This study was undertaken to investigate ... Many Andisols of the Andes have been disturbed by traditional potato-based rotation agriculture disrupting soil structure, water retention capacity and organic matter content. This study was undertaken to investigate the contribution of conservation farming technology or reduced tillage in potato-based rotations in the Colombian Andes in order to rehabilitate total and aggregated soil organic C in disturbed organic matter-rich Andisols. Soils were sampled from farms with 7-year of reduced tillage and farms with conventional farming practices. Ultrasound energy was applied to samples to disrupt aggregation and total soil C was determined in order to investigate the amount of carbon held inside the aggregates of different soil size classes. Results indicated that reduced tillage in potato-based crop rotations increased the soil C concentration and average C content in the whole profile (≈117 cm depth) by 50 and 33% (1636 t C ha?1 vs. 1224 t C ha?1), respectively, as compared to conventional farming practices. Carbon content increased 177% in the subsoil (A2 horizon, 78 -117 cm depth, from 215 to 596 t?ha?1), although most of the soil C was in the A1 horizon (between 0 -78 cm average thickness, 1097 t?ha?1). These increases show that reduced tillage enhances C stores in Andisols which are already high in organic matter. In addition, C in aggregates represented more than 80% of the total organic matter and it was positively affected by conservation practices. The C increase was preferential in the smaller macroaggregates ( 展开更多
关键词 Conservation TILLAGE SOIL organic carbon SOIL AGGREGATES ANDES POTATO
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