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Analysis of Characteristics of Snow Accumulation and Its Meteorological Influencing Factors during a Snowstorm Process in Ulanqab City
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作者 Nan ZHAO Xinyu CHEN 《Meteorological and Environmental Research》 2024年第2期10-13,21,共5页
Based on the data of national observation stations of CMISS system,artificial encrypted observation data of snow depth,ERA5 reanalysis data,the snowfall process in Ulanqab City from March 17 to 19,2022 was analyzed.It... Based on the data of national observation stations of CMISS system,artificial encrypted observation data of snow depth,ERA5 reanalysis data,the snowfall process in Ulanqab City from March 17 to 19,2022 was analyzed.It is found that the influencing system of the snowfall process was upper-air trough combined with ground inverted trough.Snowfall was not proportional to snow depth,and the relationship between the maximum snow depth and total snowfall varied in different value intervals.A large intensity of snowfall was a necessary condition for the formation of abundant accumulated snow when ground temperature was higher than 0℃.After the formation of accumulated snow,ground temperature changed less,and it was easy to produce accumulated snow as ground temperature was lower.The lower the temperature,the more conducive to the generation of accumulated snow. 展开更多
关键词 SNOWSTORM accumulated snow Snow-to-liquid ratio Influencing factors
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TaNF-YB11,a gene of NF-Y transcription factor family in Triticum aestivum,confers drought tolerance on plants via modulating osmolyte accumulation and reactive oxygen species homeostasis 被引量:3
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作者 ZHAO Ying-jia ZHANG Yan-yang +4 位作者 BAI Xin-yang LIN Rui-ze SHI Gui-qing DU Ping-ping XIAO Kai 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2022年第11期3114-3130,共17页
Transcription factors(TFs)regulate diverse stress defensive-associated physiological processes and plant stress responses.We characterized TaNF-YB11,a gene of the NF-YB TF family in Triticum aestivum,in mediating plan... Transcription factors(TFs)regulate diverse stress defensive-associated physiological processes and plant stress responses.We characterized TaNF-YB11,a gene of the NF-YB TF family in Triticum aestivum,in mediating plant drought tolerance.TaNF-YB11 harbors the conserved domains specified by its NF-YB partners and targets the nucleus after the endoplasmic reticulum(ER)assortment.Yeast two-hybrid assay indicated the interactions of TaNF-YB11 with TaNF-YA2 and TaNF-YC3,two proteins encoded by genes in the NF-YA and NF-YC families,respectively.These results suggested that the heterotrimer established among them further regulated downstream genes at the transcriptional level.The transcripts of TaNF-YB11 were promoted in roots and leaves under a 27-h drought regime.Moreover,its upregulated expression levels under drought were gradually restored following a recovery treatment,suggesting its involvement in plant drought response.TaNF-YB11 conferred improved drought tolerance on plants;the lines overexpressing target gene displayed improved phenotype and biomass compared with wild type(WT)under drought treatments due to enhancement of stomata closing,osmolyte accumulation,and cellular reactive oxygen species(ROS)homeostasis.Knockdown expression of TaP5CS2,a P5CS family gene modulating proline biosynthesis that showed upregulated expression in drought-challenged TaNF-YB11 lines,alleviated proline accumulation of plants treated by drought.Likewise,TaSOD2 and TaCAT3,two genes encoding superoxide dismutase(SOD)and catalase(CAT)that were upregulated underlying TaNF-YB11 regulation,played critical roles in ROS homeostasis via regulating SOD and CAT activities.RNA-seq analysis revealed that numerous genes associated with processes of‘cellular processes',‘environmental information processing',‘genetic information processing',‘metabolism',and‘organismal systems'modified transcription under drought underlying control of TaNF-YB11.These results suggested that the TaNF-YB11-mediated drought response is possibly accomplished through the target gene in modifying gene transcription at the global level,which modulates complicated biological processes related to drought response.TaNF-YB11 is essential in plant drought adaptation and a valuable target for molecular breeding of drought-tolerant cultivars in T.aestivum. 展开更多
关键词 wheat(Triticum aestivum L.) NF-YB transcription factor drought stress osmolyte accumulation reactive oxygen species(ROS)scavenging
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Accumulation of Heavy Metals in Maga-Pouss Rice Fields (Far-North Region, Cameroon) and Transfer to Rice Grains
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作者 Diane Madomguia Gilbert Bello Basokdou +3 位作者 Kalieu W. Appoline Isabelle Patrice Kuitekam Dongo Edouard Nya Serge Hubert Zebaze Togouet 《Agricultural Sciences》 2024年第3期311-326,共16页
Monitoring of heavy metals contamination of agricultural products and their transfer and bioaccumulation in crops like rice has become a hot topic worldwide over the last two decades. The present study was carried out... Monitoring of heavy metals contamination of agricultural products and their transfer and bioaccumulation in crops like rice has become a hot topic worldwide over the last two decades. The present study was carried out to determine the accumulation of heavy metals in rice fields and their transfer to rice grains. Soil, irrigation water and rice grains samples were gathered in Maga-Pouss, Far-North, Cameroon. Concentrations of six heavy metals (lead, cadmium, zinc, copper, iron and mercury) were evaluated by Atomic Absorption Spectrophotometer (AAS). Mercury was not detected in this study. Average concentrations of metals were in this order (in mg/kg): Fe (188.60 ± 97.06) > Pb (63.63 ± 7.11) > Cd (2.59 ± 0.29) > Zn (1.10 ± 1.05) > Cu (0.80 ± 0.73) in water and Pb (105.50 ± 31.11) > Fe (105.50 ± 31.11) > Cu (45.93 ± 14.39) > Zn (22.52 ± 6.40) > Cd (3.15 ± 0.49) in soil. Water in Maga-Pouss rice fields appears to be more harmful than the soil, notably for lead, cadmium and copper. In rice grains, heavy metals were found in this order (mg/kg): Fe (188.01 ± 82.62) > Cu (27.20 ± 0.00) > Zn (23.61 ± 12.42) > Pb (19.50 ± 19.91) > Cd (2.02 ± 1.05). The mean bioconcentration factor (BCF) of metals from soil to rice grains was in the following order: Fe (2.60) > Zn (1.05) > Cd (0.64) > Cu (0.59) > Pb (0.18). From water to rice grains, the order is: Cu (37.26) > Zn (22.49) > Cd (6.97) > Pb (2.74) > Fe (1.94). Rice field pH and electrical conductivity favored the uptake of lead, copper and cadmium by rice grains. The findings of this study will be good documentation for risk assessment, and decision-making by environmental managers in this region. 展开更多
关键词 Heavy Metals Rice Field Bioconcenration factor Maga-Pouss accumulation
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<i>Trapa japonica</i>Flerov Extract Attenuates Lipid Accumulation through Downregulation of Adipogenic Transcription Factors in 3T3-L1 Cells 被引量:1
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作者 Mi Jin Kim Kyung Ran Im Kyung-Sup Yoon 《American Journal of Molecular Biology》 2015年第2期32-41,共10页
Obesity is a major human health problem associated with various diseases, including cardiac injury and type 2 diabetes. Trapa japonica Flerov (TJF) has been used in traditional oriental medicine to treat diabetes. In ... Obesity is a major human health problem associated with various diseases, including cardiac injury and type 2 diabetes. Trapa japonica Flerov (TJF) has been used in traditional oriental medicine to treat diabetes. In this study, we evaluated the inhibitory effect of and the mechanism underlying the effect of TJF extract on adipogenesis in 3T3-L1 cells. The effects of TJF extract on cell viability were analyzed using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, and the anti-adipogenic effect was measured by oil red O staining. The expression of peroxisomal proliferator activated receptor (PPAR)γ, CCAAT/enhancer-binding protein-α (C/EBP)α, adenosine monophosphate-activated protein kinase (AMPK), acetyl-CoA carboxylase (ACC), adiponectin, and fatty acid binding protein (FABP)4 involved in adipogenesis was determined by western blot analysis. TJF extract effectively inhibited lipid accumulation and the expression of PPARγ and C/EBPα in 3T3-L1 cells. TJF also increased the phosphorylation of AMPK and ACC, and decreased the expression of adiponectin and FABP4. These results indicate that TJF extract exerts its anti-obesity effect through the downregulation of adipogenic transcription factors and adipogenic marker genes. 展开更多
关键词 3T3-L1 Cells Adipogenic Transcription factors Lipid accumulation TRAPA JAPONICA Flerov EXTRACT
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Migration and accumulation mechanisms and main controlling factors of tight oil enrichment in a continental lake basin 被引量:2
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作者 HU Suyun TAO Shizhen +12 位作者 WANG Min PANG Zhenglian BAI Bin CHEN Yanyan LU Shuangfang CHEN Yue YANG Yiqing JIN Xu JIA Jinhua WANG Jian ZHANG Tianshu LIN Senhu WU Yinye 《Petroleum Exploration and Development》 SCIE 2023年第3期547-557,共11页
Based on the typical dissection of various onshore tight oil fields in China,the tight oil migration and accumulation mechanism and enrichment-controlling factors in continental lake basins are analyzed through nuclea... Based on the typical dissection of various onshore tight oil fields in China,the tight oil migration and accumulation mechanism and enrichment-controlling factors in continental lake basins are analyzed through nuclear magnetic resonance(NMR)displacement physical simulation and Lattice Boltzmann numerical simulation by using the samples of source rock,reservoir rock and crude oil.In continental lake basins,the dynamic forces driving hydrocarbon generation and expulsion of high-quality source rocks are the foundational power that determines the charging efficiency and accumulation effect of tight oil,the oil migration resistance is a key element that influences the charging efficiency and accumulation effect of tight oil,and the coupling of charging force with pore-throat resistance in tight reservoir controls the tight oil accumulation and sweet spot enrichment.The degree of tight oil enrichment in continental lake basins is controlled by four factors:source rock,reservoir pore-throat size,anisotropy of reservoir structure,and fractures.The high-quality source rocks control the near-source distribution of tight oil,reservoir physical properties and pore-throat size are positively correlated with the degree of tight oil enrichment,the anisotropy of reservoir structure reveals that the parallel migration rate is the highest,and intralayer fractures can improve the migration and accumulation efficiency and the oil saturation. 展开更多
关键词 tight oil NMR displacement physical simulation Lattice Boltzmann numerical simulation migration and accumulation mechanism enrichment-controlling factor continental lake basin tight reservoir
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Major controlling factors and hydrocarbon accumulation models of large-scale lithologic reservoirs in shallow strata around the Bozhong sag,Bohai Bay Basin,China 被引量:1
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作者 ZHOU Xinhuai WANG Deying +2 位作者 YU Haibo YANG Haifeng LI Long 《Petroleum Exploration and Development》 CSCD 2022年第4期758-769,共12页
Based on the practice of oil and gas exploration and the analysis of shallow lithologic reservoirs,combined with the allocation relationship and enrichment law of oil and gas accumulation factors,main controlling fact... Based on the practice of oil and gas exploration and the analysis of shallow lithologic reservoirs,combined with the allocation relationship and enrichment law of oil and gas accumulation factors,main controlling factors and models of hydrocarbon accumulation of large lithologic reservoirs in shallow strata around the Bozhong sag are summarized,and favorable exploration areas are proposed.The coupling of the four factors of“ridge-fault-sand-zone”is crucial for the hydrocarbon enrichment in the shallow lithologic reservoirs.The convergence intensity of deep convergence ridges is the basis for shallow oil and gas enrichment,the activity intensity of large fault cutting ridges and the thickness of cap rocks control the vertical migration ability of oil and gas,the coupling degree of large sand bodies and fault cutting ridges control large-scale oil and gas filling,the fault sealing ability of structural stress concentration zones affects the enrichment degree of lithologic oil and gas reservoirs.Three enrichment models including uplift convergence type,steep slope sand convergence type and depression uplift convergence type are established through the case study of lithologic reservoirs in shallow strata around the Bozhong sag. 展开更多
关键词 shallow lithologic reservoir main controlling factors convergence ridge accumulation model Bozhong sag Bohai Bay Basin
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Differences and controlling factors of composite hydrocarbon accumulations in the Tazhong uplift, Tarim Basin, NW China 被引量:2
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作者 JIANG Tongwen HAN Jianfa +5 位作者 WU Guanghui YU Hongfeng SU Zhou XIONG Chang CHEN Jun ZHANG Huifang 《Petroleum Exploration and Development》 2020年第2期229-241,共13页
Based on three-dimensional seismic interpretation, structural and sedimentary feature analysis, and examination of fluid properties and production dynamics, the regularity and main controlling factors of hydrocarbon a... Based on three-dimensional seismic interpretation, structural and sedimentary feature analysis, and examination of fluid properties and production dynamics, the regularity and main controlling factors of hydrocarbon accumulation in the Tazhong uplift, Tarim Basin are investigated. The results show that the oil and gas in the Tazhong uplift has the characteristics of complex accumulation mainly controlled by faults, and more than 80% of the oil and gas reserves are enriched along fault zones. There are large thrust and strike-slip faults in the Tazhong uplift, and the coupling relationship between the formation and evolution of the faults and accumulation determine the difference in complex oil and gas accumulations. The active scale and stage of faults determine the fullness of the traps and the balance of the phase, that is, the blocking of the transport system, the insufficient filling of oil and gas, and the unsteady state of fluid accumulation are dependent on the faults. The multi-period tectonic sedimentary evolution controls the differences of trap conditions in the fault zones, and the multi-phase hydrocarbon migration and accumulation causes the differences of fluid distribution in the fault zones. The theory of differential oil and gas accumulation controlled by fault is the key to the overall evaluation, three-dimensional development and discovery of new reserves in the Tazhong uplift. 展开更多
关键词 Tarim Basin Tazhong uplift fault zone complex oil and gas accumulation oil and gas distribution difference main controlling factor
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Agricultural Ecological Capital: Factor Structure,Value Assessment and Accumulation Mechanism
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作者 Li Pingheng Yan Lidong +1 位作者 Zhu Xiaorong Deng Yuanjian 《Meteorological and Environmental Research》 CAS 2017年第6期1-5,14,共6页
As a kind of important new capital form,agricultural ecological capital plays a decisive role in guaranteeing healthy development of agricultural ecological economy. Therefore scientific understanding agricultural eco... As a kind of important new capital form,agricultural ecological capital plays a decisive role in guaranteeing healthy development of agricultural ecological economy. Therefore scientific understanding agricultural ecological capital is favorable for developing agricultural ecological economy,while clarifying factor structure,value assessment and accumulation mechanism of agricultural ecological capital is important content of understanding agricultural ecological capital. In this paper,factor structure of agricultural ecological capital is firstly elaborated,and it is thought that agricultural ecological capital is the unity of agricultural ecological environment,agricultural ecological resource and agricultural ecological system. Then agricultural ecological capital value is assessed according to use value method and non use value method,thereby realizing quantification of agricultural ecological capital. After agricultural ecological capital passes through value assessment,the value is more clear,which creates condition for agricultural ecological capital accumulation. Finally accumulation mechanism of agricultural ecological capital is analyzed. Accumulation channel of agricultural ecological capital is explored from natural and human factors,and it is found that agricultural ecological capital accumulates in the forms of agricultural ecological restoration and agricultural ecological compensation. 展开更多
关键词 AGRICULTURAL ECOLOGICAL CAPITAL factor VALUE accumulation
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The molecular mechanism of WRINKLED1 transcription factor regulating oil accumulation in developing seeds of castor bean
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作者 Qing Tan Bing Han +5 位作者 Mohammad Enamul Haque Ye-Lan Li Yue Wang Di Wu Shi-Bo Wu Ai-Zhong Liu 《Plant Diversity》 SCIE CAS CSCD 2023年第4期469-478,共10页
The transcription factor WRINKLED1(WRI1),a member of AP2 gene family that contain typical AP2 domains,has been considered as a master regulator regulating oil biosynthesis in oilseeds.However,the regulatory mechanism ... The transcription factor WRINKLED1(WRI1),a member of AP2 gene family that contain typical AP2 domains,has been considered as a master regulator regulating oil biosynthesis in oilseeds.However,the regulatory mechanism of RcWRI1 in regulating oil accumulation during seed development has not been clearly addressed.Castor bean(Ricinus communis)is one of the most important non-edible oil crops and its seed oils are rich in hydroxy fatty acids,widely applied in industry.In this study,based on castor bean reference genome,three RcWRIs genes(RcWRI1,RcWRI2 and RcWRI3)were identified and the expressed association of RcWRI1 with oil accumulation were determined.Heterologous transformation of RcWRI1 significantly increased oil content in tobacco leaf,confirming that RcWRI1 activate lipid biosynthesis pathway.Using DNA Affinity Purification sequencing(DAP-seq)technology,we confirmed RcWRI1 binding with Transcription Start Site of genes and identified 7961 WRI1-binding candidate genes.Functionally,these identified genes were mainly involved in diverse metabolism pathways(including lipid biosynthesis).Three cis-elements AW-box([CnTnG](n)7[CG])and AW-boxes like([GnAnC](n)6[GC]/[GnAnC](n)7[G])bound with RcWRI1 were identified.Co-expression network analysis of RcWRI1 further found that RcWRI1 might be widely involved in biosynthesis of storage materials during seed development.In particular,yeast one hybrid experiments found that both AP2 domains within RcWRI1 were required in binding targeted genes.These results not only provide new evidence to understand the regulatory mechanism of RcWRI1 in regulation of oil accumulation during castor bean seed development,but also give candidate gene resource for subsequent genetic improvement toward increasing oil content in oilseed crops. 展开更多
关键词 Castor bean WRI transcription factor Oil accumulation Developing seeds Lipid gene
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Main Controlling Factors and Accumulation Model of Chang 9 Reservoir in Northwest Ordos Basin, China
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作者 Zhang Weigang Chen Gang 《China Oil & Gas》 CAS 2019年第6期39-44,共6页
In northwestern Ordos Basin, the Triassic reservoir Chang 9 has favorable reservoir forming conditions, extensive reservoir development, and huge potential for oil exploration and exploitation. Studying the main contr... In northwestern Ordos Basin, the Triassic reservoir Chang 9 has favorable reservoir forming conditions, extensive reservoir development, and huge potential for oil exploration and exploitation. Studying the main controlling factors and accumulation model of Chang 9 reservoir in this area can provide a basis for the production targets, and assist in formulating reasonable development technology policy. In this paper, to explore and summarize the hydrocarbon accumulation model, the Chang 9 reservoir were analyzed from the aspects of oil source, fracture, oil migration, structure, lithology and reservoir physical properties for the main controlling factors in this area. Organic geochemical and geological comprehensive analysis that the oil-source of the Chang 9 reservoir in the northwest of Ordos Basin is derived from Chang 7 hydrocarbon source rocks. The fractures provide a sound channel for the "vertical multi-point filling" of the oil source from Chang 7 to Chang 9. The crude oil migrates vertically from Chang 7 to Chang 9, then expands horizontally to form a reservoir. Structures play an important role in controlling the distribution of reservoirs, the control by sand in small layer and physical property is also obvious. This paper creatively establishes the reservoir accumulation model of Chang 9 in northwest of Ordos Basin, which is characterized by Vertical multi-point filling, horizontal expansion becomes oil pool. It reveals the genetic mechanism of the development of Chang 9 multi-reservoir in the study area, which provides guidance for exploration and evaluation deployment. 展开更多
关键词 Ordos Basin Chang 9 reservoir petroleum accumulation main control factors hydrocarbon pooling patterns
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Fracture development in shale and its relationship to gas accumulation 被引量:39
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作者 Wenlong Ding Chao Li +4 位作者 Chunyan Li Changchun Xu Kai Jiu Weite Zeng Liming Wu 《Geoscience Frontiers》 CAS 2012年第1期97-105,共9页
Shale with high quartz, feldspar and carbonate, will have low Poisson's ratio, high Young's modulus and high brittleness. As a result, the shale is conducive to produce natural and induced fractures under external f... Shale with high quartz, feldspar and carbonate, will have low Poisson's ratio, high Young's modulus and high brittleness. As a result, the shale is conducive to produce natural and induced fractures under external forces. In general, there is a good correlation between fracture development in shale and the volume of brittle minerals present. Shale with high TOC or abnormally high pressure has well-developed fractures. Shale fracture development also shows a positive correlation with total gas accumulation and free gas volume, i.e., the better shale fractures are developed, the greater the gas accumulation and therefore the higher the gas production. Fractures provide migration conduits and accumulation spaces for natural gas and formation water, which are favorable for the volumetric increase of free natural gas. Wider fractures in shale result in gas loss. In North America, there is a high success ratio of shale gas exploration and high gas production from high-angle fracture zones in shale. Good natural gas shows or low yield producers in the Lower Paleozoic marine organic matter-rich rocks in the Sichuan Basin are closely related to the degree of fracture development in brittle shales. 展开更多
关键词 SHALE FRACTURE Dominant factor Gas accumulation Gas production
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A hydrocarbon enrichment model and prediction of favorable accumulation areas in complicated superimposed basins in China 被引量:16
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作者 Pang Xiongqi Meng Qingyang +2 位作者 Jiang Zhenxue Liu Luofu Lu Xiuxiang 《Petroleum Science》 SCIE CAS CSCD 2010年第1期10-19,共10页
The geologic conditions of superimposed basins in China are very complicated. This is mainly shown by multi-phase structural evolution, multiple sets of source-reservoir-cap rock combinations, multiple stages of hydro... The geologic conditions of superimposed basins in China are very complicated. This is mainly shown by multi-phase structural evolution, multiple sets of source-reservoir-cap rock combinations, multiple stages of hydrocarbon generation and expulsion from source rocks, multi-cycle hydrocarbon enrichment and accumulation, and multi-phase reservoir adjustment and reconstruction. The enrichment, accumulation and distribution of hydrocarbon is mainly controlled by the source rock kitchen, paleo- anticline, regional cap rock and intensity of tectonic movement. In this paper, the T-BCMS model has been developed to predict favorable areas of hydrocarbon accumulation in complicated superimposed basins according to time and spatial relationships among five key factors. The five factors include unconformity surface representing tectonic balancing (B), regional cap rock representing hydrocarbon protection (C), paleo-anticline representing hydrocarbon migration and accumulation (M), source rock kitchen representing hydrocarbon generation and expulsion (S) and geological time (T). There are three necessary conditions to form favorable areas of hydrocarbon accumulation. First, four key factors BCMS should be strictly in the order of BCMS from top to bottom. Second, superimposition of four key factors BCMS in the same area is the most favorable for hydrocarbon accumulation. Third, vertically ordered combination and superimposition in the same area of BCMS should occur at the same geological time. The model has been used to predict the most favorable exploration areas in Ordovician in the Tarim Basin in the main hydrocarbon accumulation periods. The result shows that 95% of the discovered Ordovician hydrocarbon reservoirs are located in the predicted areas, which indicates the feasibility and reliability of the key factor matching T-BCMS model for hydrocarbon accumulation and enrichment. 展开更多
关键词 Complicated superimposed basin key factor matching T-BCMS model favorable area for hydrocarbon accumulation hydrocarbon distribution prediction
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Hydrocarbon accumulation principles in troughs within faulted depressions and their significance in exploration 被引量:5
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作者 Zhao Xianzheng Jin Fengming Wang Quan Lu Xuejun 《Petroleum Science》 SCIE CAS CSCD 2011年第1期1-10,共10页
Previously,troughs in continental faulted depressions were usually considered as a zone of hydrocarbon generation and expulsion rather than a zone for hydrocarbon accumulation.If they were confirmed to be the source k... Previously,troughs in continental faulted depressions were usually considered as a zone of hydrocarbon generation and expulsion rather than a zone for hydrocarbon accumulation.If they were confirmed to be the source kitchen,the possibility that they could constitute potential plays would be overlooked in the subsequent exploration program.Based on the hydrocarbon exploration practice of the Jizhong Depression and the Erlian Basin in the past several years,this paper discusses a new understanding that reservoir distribution is controlled by multiple factors and lithological accumulations are more likely to form in trough areas.It further documents the three main factors controlling the formation of large lithological hydrocarbon accumulations in trough areas.The paper also discusses the new concept that structural and lithological accumulations not only co-exist but also complement each other.We propose that fan-delta fronts on inverted steep slopes in troughs,delta fronts and sublacustrine fans on gentle slopes,channel sands along toes of fault scarps are favorable locations for discovery of new oil accumulations.The application of this concept has led to the discovery of several hundreds of million tonnes of oil in place in trough areas in the Jizhong Depression and the Erlian Basin. 展开更多
关键词 Sand distribution multiple controlling factors preferential hydrocarbon accumulation accumulation in troughs accumulation model exploration method
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Biogenic silicate accumulation in sediments, Jiaozhou Bay 被引量:1
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作者 李学刚 宋金明 +4 位作者 戴纪翠 袁华茂 李宁 李凤业 孙松 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2006年第3期270-277,共8页
It has been widely recognized that low silicate content in seawater is a major limiting factor to phytoplankton primary production in Jiaozhou Bay. However the reason of Si-limitation remains poorly understood. In the... It has been widely recognized that low silicate content in seawater is a major limiting factor to phytoplankton primary production in Jiaozhou Bay. However the reason of Si-limitation remains poorly understood. In the present study we measured the biogenic silicate content and discussed the ac- cumulation of silicate in Jiaozhou Bay sediment. The results show that the biogenic silica content in the sediment of the Jiaozhou Bay is obviously much higher than those in the Yellow Sea and the Bohai Sea. The BSi:TN ratios and BSi:16P ratios in the sediment are > 1 and the OC:BSi ratio in sediment is lower than these of Redfield ratio (106:16), indicating that the decomposition rate of OC is much higher than that for BSi in similar conditions. Therefore, the majority of the biogenic silicate was buried and thus did not participate in silicate recycling. Silicate accumulation in sediment may explain why Si limits the phytoplankton growth in the Jiaozhou Bay. Comparing the flux of biogenic silicate from sediments with primary production rate, it can be concluded that only 15.5% of biogenic silicate is hydrolyzed during the journey from surface to bottom in seawater, thus approximate 84.5% of biogenic silicate could reach the bottom. The silicate releasing rate from the sediment to seawater is considerably lower than that of sedi- mentation of biogenic silicate, indicating silicate accumulation in sediment too. In a word, the silicate ac- cumulation in sediment is the key reason of silicate limiting to phytoplankton growth in Jiaozhou Bay. 展开更多
关键词 biogenic silicate accumulation limiting factor Jiaozhou Bay
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An evaluation of the bioavailability and bioaccumulation of selected metalso ccurring in a wetland area on the volcanic island of Guam,Western Pacific Ocean
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作者 Bob Wilson Brian Pyatt Gary Denton 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第11期1547-1551,共5页
This initial research examined the presence, distribution and bioavailability of Cu, Cr, Ni, Mn and Fe in a wetland area of southern Guam. The research sites are within an area covered with saporite, a soil type deriv... This initial research examined the presence, distribution and bioavailability of Cu, Cr, Ni, Mn and Fe in a wetland area of southern Guam. The research sites are within an area covered with saporite, a soil type derived from volcanic deposits on the island. Leaf tissue of Pandanus tectorius was extracted and analysed to determine the bioaccumulation of the target metals. Metal accumulation at sites considered aerobic and anaerobic was investigated together with an attempt to correlate actual accumulation of the target metals in the plant tissue with a recognised bioavailability indicator, in this case, three step sequential extraction scheme. Manganese was found to be accumulated in relatively high concentrations and to a lesser extent Cu was also accumulated. Chromium, Ni and Fe however exhibited very low accumulation factors. Accumulation of Mn in particular was significantly affected by aerobic conditions whereas the converse effect was experienced by Cu. Significant correlation between various steps of a Sequential Extraction Scheme and actual accumulation was not achieved although the degree of aerobic conditions at each site and soil pH did affect concentrations of metals extracted by differing steps of SES. Results obtained suggest that further research in the area should be undertaken using different plant species and tissues. 展开更多
关键词 GUAM BIOaccumulation sequential extraction BIOAVAILABILITY accumulation factor heavy metals
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Accumulation of heavy metals in stemwood of forest tree plantations fertilized with different sewage sludge doses
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作者 Marius Praspaliauskas Nerijus Pedisius Audrius Gradeckas 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第2期345-359,共15页
The levels of heavy metals that accumulated in stemwood of mature trees grown for 20 years in a plantation in an abandoned peat quarry in areas that were fertilized with different amounts of domestic sewage sludge(180... The levels of heavy metals that accumulated in stemwood of mature trees grown for 20 years in a plantation in an abandoned peat quarry in areas that were fertilized with different amounts of domestic sewage sludge(180,360,and720 Mg ha-1on a dry basis) were compared with trees grown in a reference nonfertilized area.Included in the study was a hybrid poplar(Populus tremula x Populus tremuloides) developed for use as an energy crop,three local tree species and one introduced tree species.The concentrations of Cd,Cr,Cu,Ni,Pb and Zn in the stemwood of the trees grown in the fertilized and nonfertilized fields were determined,and found to be significantly lower than their respective concentrations in the soil.Cd and Cr were found only in several wood samples at concentrations close to the limits of detection or qualification; therefore,they were not analyzed further.A correlation analysis suggested that 75%of the correlations between the concentrations of heavy metals in the stemwood and the concentrations in the soil were negative.The ability of trees to accumulate the metals from soil in most cases decreased for Cu and Ni; however,the correlations were not as clear for Pb and Zn.The followingsequence for the levels of heavy metals found in the stemwood of the analysed trees was Zn [ Pb [ Ni [ Cu [(Cr,Cd).The results of this study showed that the levels of heavy metals in the studied wood would not exceed the permitted limits of heavy metal pollution in the air and ash when used for energy production. 展开更多
关键词 Forest tree plantation accumulation factor Saturation limit BIOSOLIDS Heavy metals Long-term field experiments Biofuels
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Canonical Correlation Factors Causing the Formation of Accumulated Sand-belts along the Oasis Fringe in Hexi Corridor
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作者 Chang Zhaofeng Wang Qiangqiang +7 位作者 Zhang Jianhui Tang Jinnian Zhu Shujuan Fan Baoli Zhang Dabiao Liu Shizeng Zhang Guozhong Li Aide 《Animal Husbandry and Feed Science》 CAS 2014年第5期279-284,共6页
Accumulated sand-belts refer to those formed along the oasis fringe,especially at the upwind location,due to the accumulation of sand blocked by farmland windbreak. In the 60 years since the foundation of new China,a ... Accumulated sand-belts refer to those formed along the oasis fringe,especially at the upwind location,due to the accumulation of sand blocked by farmland windbreak. In the 60 years since the foundation of new China,a lot of trees have been planted for desertification combating in northwest and north China,thus,accumulated sand-belts were formed at the upwind location. The formation and the ecological effects of the accumulated sand-belts along the oasis fringe is a new scientific concern. To study the formation causes of these belts in Hexi corridor,21 samples were selected,and the height / width of the belts,as well as the vegetation,soil,soil moisture and climatic factors were investigated. This paper analyzed the correlation between the height / width of the belts and the vegetation,soil,soil moisture and climatic factors using the methods of variance analysis,correlation analysis and canonical correlation analysis. The results indicate that: the accumulated sand-belts take a trend of being high and wide in the east whereas low and narrow in the west,and most of the parts tend to be stable; the species on the belts are dominated by Tamarix austromongolica,the vegetation cover and the pure vegetation cover of different dominant species on the leeward slope of the accumulated sand-belts vary significantly. The canonical correlation analysis shows that: the height and width of accumulated sand-belt is the interaction of precipitation,distance to the sand source,leeward vegetation cover and annual average wind speed. Moreover,the height of accumulated sand-belts are negatively correlated to the soil moisture at the depth of 30- 50 cm,air humidity and leeward vegetation cover,and the width of the belts is also negatively correlated with the distance to the sand source. The ecological effects of the accumulated sand-belts are both positive( stopping sands from moving into farmland,protective role as an obstacle)and negative( when the belts decay and activate one day,they will become the new sand sources). At present,there are no signs showing the negative effects of the belts. The ecological effects of the accumulated sand-belts are: firstly the protective role as an obstacle,and secondly to intercept and reduce the sands moving into farmlands. 展开更多
关键词 Height of accumulated sand-belt Width of accumulated sand-belt Climatic and environmental factors Canonical correlation factors Ecological effects Hexi of Gansu
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Inversion of the Strain Accumulation State in Crustal Interior from Observations of Earth Tide Tilts
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作者 Wu Yilin,Li Ping,Chen Guangqi and Li XudongInstitute of Seismology,SSB,Wuhan 430071,China 《Earthquake Research in China》 1994年第4期72-80,共9页
The strain accumulation state in crustal interior and its migration trend can be inverted from observational data of earth tide tilts.In China,large earthquakes frequently occur in the border area between Yunnan and S... The strain accumulation state in crustal interior and its migration trend can be inverted from observational data of earth tide tilts.In China,large earthquakes frequently occur in the border area between Yunnan and Sichuan Provinces.Using the observational data for years from 7 stations in this area,γ(the amplitude factor of earth tide tilts)values that characterize the strain accumulation state in crustal interior have been inverted in this paper.It has been found out that,Ms】5 events in the area often occur when γreaches an anomaly value.Using the time-space collocational stereomodelling the migration trend of strain accumulation can be determined to make a prediction for the probable location of a forthcoming earthquake in the area. 展开更多
关键词 Earth TIDE AMPLITUDE factor Strain accumulation
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Statistical Analysis of Influencing Factors of Temporal and Spatial Variation Patterns of Decadal Accumulative Heavy Rainfall in China
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作者 Kong Feng Wang Yifei Lu Lili 《Journal of Environmental Science and Engineering(A)》 2017年第5期225-238,共14页
Daily precipitation analyses for 659 Chinese meteorological stations from 1951 to 2010 show that the rapid urbanization may have triggered the significant increase of heavy rainfall in China. During the last decades, ... Daily precipitation analyses for 659 Chinese meteorological stations from 1951 to 2010 show that the rapid urbanization may have triggered the significant increase of heavy rainfall in China. During the last decades, HRAs (Heavy Rainfall Amounts), HRDs (Heavy Rainfall Days) and HRI (Heavy Rainfall Intensity) in China have increased. Impressively, the upward trends are not randomly observed among stations, but of robust consistency with quite large regional scale over large widely and significantly. Compared to the 1950s, the HRA, HRD, and HRI increased by 68.71%, 60.15% and 11.52% during the 2000s. The significant increase of accumulative heavy rainfall appears firstly in the southeastern coasts in the early period, and then gradually expands to the central, southwest, north and northeast China. Rapid urbanization is very likely the main cause of large-scale heavy rainfall increase in China. The urbanization indicators including the industrial production output (GDP2), UP (Urban Population) and annual average HDs (Haze Days) are in good agreement with the heavy rainfall variations, and these indicators can statistically explain the variance of HRA, HRD and HRI by 61.54%, 58.48% and 65.54%, respectively. Meanwhile, the explained variance by leading climate indices including WPSH (Western Pacific Subtropical High), ENSO (El Nino-Southern Oscillation), AMO (Atlantic Multi-decadal Oscillation) and AAO (Antarctic Oscillation) are respectively 24.30%, 26.23% and 21.92%, being only about 1/3 of the urbanization-related variance. Panel data analysis of county-level total population and annual average visibility days less than 10 km also show that these two indicators have significant correlation with decadal HRA, HRD & HRI and the spatial correlation coefficient increases gradually with time. These consistent temporal and spatial features strongly suggest that rapid urbanization most likely triggered the steady increase of heavy rainfall over China during the recent decades. 展开更多
关键词 Climate change accumulated heavy rainfall URBANIZATION natural factors China.
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A Case Study on Parameters Influencing Dust Accumulation on CSP Reflectors
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作者 Selene Pennetta Francesco Anglani +1 位作者 John Barry Shengzhe Yu 《Journal of Energy and Power Engineering》 2016年第2期73-81,共9页
The effect of dust accumulation on CST (concentrated solar thermal) reflectors is to deflect, or scatter, incident light rays missing the receiver with a subsequent power produced loss. Dust fouling is site specific... The effect of dust accumulation on CST (concentrated solar thermal) reflectors is to deflect, or scatter, incident light rays missing the receiver with a subsequent power produced loss. Dust fouling is site specific, and the understanding of interactions between different weather and or environmental parameters is crucial for plant profitability. This research intends to provide useful insights on the interaction between the most relevant weather parameters affecting soil accumulation. Results show a significant dependency of dust concentration versus humidity and ambient temperature, as well as a nexus between wind speed and ambient temperature seems to exist. As long as the temperature decreases an increase of humidity and dust concentration occurs. This phenomenon takes place mostly overnight till the first hours of the morning. Therefore, mirror's reflectance looks extremely affected by dust accumulation because of high humidity rate during the night and dews of early morning. Further investigations are required to validate the hypothesis that, a more effective cleaning activitie to restore plants' reflectivity are to be carried out during the early morning. 展开更多
关键词 CSP plant reflectivity degradation dust accumulation dust concentration environmental factors.
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