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Effect of ground cover changes on solar radiation absorption in Three Northeastern Provinces of China
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作者 SHUAI Yanmin CHEN Yangyang +3 位作者 SHAO Congying TIAN Yanjun QU Ge HUANG Jiapeng 《地球环境学报》 CSCD 2024年第4期675-690,共16页
Background,aim,and scope Solar radiation is the main source of energy for terrestrial ecosystems.Small changes in the absorption of solar radiation at the ground surface can have a significant impact on the climatic e... Background,aim,and scope Solar radiation is the main source of energy for terrestrial ecosystems.Small changes in the absorption of solar radiation at the ground surface can have a significant impact on the climatic environment.Natural and anthropogenic changes in ground cover are important factors affecting the absorption of solar radiation at the ground surface.This phenomenon is particularly pronounced in the mid and high latitudes.In order to quantify the inf luence of surface cover change on the absorption of solar radiation at the surface and to provide a scientific basis for changes in the climatic environment,this paper analyzed ground cover change,ground absorbed solar radiation change and the effect of ground cover change on ground absorbed solar radiation in the Three Northeastern Provinces of China from 2001 to 2018.Materials and methods In this study,the Three Northeastern Provinces of China were used as the study area.Firstly,satellite remote sensing data were used to obtain land cover data and albedo data for Aug.1st of each year in 2001,2005,2010,2015 and 2018.The albedo data were further used to calculate the absorbed solar radiation data at the ground surface.Next,the land cover data were used to count the area changes and shifts of different land classes over the five-year period.The land cover data were overlaid with the surface absorbed solar radiation data to obtain the mean and standard deviation of radiation absorption for different ground classes.The surface absorbed solar radiation data were subtracted to obtain the changes in surface absorbed solar radiation for 2001-2005,2005-2010,2010-2015 and 2015-2018.Ultimately,we used a combination of shifted changes in ground classes and changes in surface absorbed solar radiation data,with unchanged ground classes as a baseline and data such as slope orientation as an aid.We analyzed the effect of ground cover change on surface absorbed solar radiation at regional and pixel point scales.Results(1)The area of woodland and waters in the Three Northeastern Provinces of China increased and then decreased from 2001 to 2018,with an overall increase of 3.96%and 10.51%respectively.Cropland decreased and then increased,with a total decrease of 1.22%.Grassland continued to decrease,with an overall decrease of 19.36%.Building sites increased all the time,with a total increase of 11.08%.The main types of ground cover shifted were woodland,cropland and grassland.The main factors for the change in ground cover were China’s woodland protection policy and the saturation of the total woodland stock.(2)The five ground types absorb solar radiation in the order of waters>building sites>woodland>grassland>cropland.The surface absorption of solar radiation in the Songnen Plain,the Sanjiang Plain and the Songhua River Basin flowing through the Songnen Plain and the Sanjiang Plain varies significantly,by more than 25 W·m^(-2).(3)Changes in the ground cover type affected the absorption of solar radiation energy by the ground surface.There was a clear trend of interconversion between waters and cropland/grassland,cropland and woodland/grassland.In particular,the conversion of waters to both cropland and grassland radiation absorption values decreased significantly,while the opposite increased.The absolute difference between waters and cropland was a maximum of -156.66 W·m^(-2)in 2010-2015,and between waters and grassland was a maximum of 102.36 W·m^(-2) in 2005-2010.The radiative absorption values of woodland and grassland reclamation declined and conversely increased.The absolute difference between woodland and cropland was a maximum of-13.94 W·m^(-2) in 2010-2015 when woodland converted to cropland,and between grassland and cropland was a maximum of 22.36 W·m^(-2) in 2001-2005 when cropland converted to grassland,respectively.Discussion Ground cover changes in the Three Northeastern Provinces of China from 2001-2018 were inextricably linked to natural factors and the inf luence of Chinese national policies.The main inf luencing factors were China’s woodland protection policy,restoration of woodland fire sites,saturation of total woodland,optimization of cropland patterns,sanding of grassland,expansion of water conservancy projects,and urbanization expansion.There were differences in the radiation absorption characteristics of different ground cover types.This was due to the nature of the ground type itself and the regional environment.When ground cover types changed,their ability to absorb solar radiation also changed.The degree of change could be inf luenced by different ground types and different environmental factors.Different spatial scales can also produce variability.We need to consider the effects of ground cover change on the absorption of solar radiation at the surface in an integrated and comprehensive way.Conclusions The Three Northeastern Provinces of China had frequent changes in ground cover from 2001-2018,with the area of grassland decreased by almost 20%.These changes were due to natural environmental change and policies issued by China since the 21st century.The extent to which solar radiation was absorbed by different ground cover types was different,with grassland being the strongest and cropland the least.In the past few years,the Songnen Plain and Sanjiang Plain regions were the most significant changes in the absorption of solar radiation by the ground cover.The change in ground cover type led to a change in solar radiation absorption at the ground surface,with the conversion of waters to cropland or grassland and the conversion of cropland to woodland or grassland showing the greatest change in radiation absorption values,and vice versa.Of these,the absolute difference in the conversion of waters to cropland amounts to-156.66 W·m^(-2) in 2010-2015.The variation in the absorption of solar radiation at the ground surface was related to the characteristics of the ground class itself,but was also limited by the regional environment.Recommendations and perspectives This study showed that surface cover change can affect the absorption of solar radiation at the surface to varying degrees.The unchanged land classes were used as a comparative analysis in this paper,and it was clear from the paper that some of the unchanged land classes showed significant changes in radiation absorption that should be of interest in future studies. 展开更多
关键词 land surface cover changes surface absorption of solar radiation the Three Northeastern provinces ALBEDO
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Review on Drought Disasters in the Five Provinces of Northern China in 1920
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作者 王鑫宏 《Meteorological and Environmental Research》 CAS 2010年第4期87-91,共5页
This paper analyzed the severe drought that took place in the five provinces of Northern China in 1920.Study suggested that the severe damage caused by the drought was resulted from many reasons,such as certain specif... This paper analyzed the severe drought that took place in the five provinces of Northern China in 1920.Study suggested that the severe damage caused by the drought was resulted from many reasons,such as certain specific natural conditions,deterioration of ecological environment,malformations of the rural economy and turbulence of domestic politics.However,some new phenomena took shapes during this time disaster relief activity. 展开更多
关键词 1920 Five provinces in northern China DROUGHT Characteristics Cause of formation Disaster relief China
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A Microscopic and Nanoscale Understanding of the Formation of Gold Geochemical Provinces 被引量:5
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作者 YE Rong WANG Xueqiu ZHANG Bimin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第3期995-1003,共9页
Gold geochemical provinces in China were delineated through stream sediment or catchment sediment sampling in this study.Each gold geochemical province delineated by a threshold value of 2.5 ng/g covers an area of tho... Gold geochemical provinces in China were delineated through stream sediment or catchment sediment sampling in this study.Each gold geochemical province delineated by a threshold value of 2.5 ng/g covers an area of thousands of kilometers.It is a dilemma that geochemists traditionally thought that gold could not migrate for a long distance in rivers or streams to form a large-scale geochemical anomaly due to its chemical inertness and high specific density.The quantitative spectroscopic analysis and observations under a scanning electron microscope (SEM) indicate the presence of submicroscopic gold particles (〈5 μm in diameter) in large quantities,and observations under a Transmission Electron Microscopy (TEM) further suggest the presence of nanoscale gold particles (several tens of nanometre in diameter) in ores,rocks,soils and stream sediments.Particularly,submicroscopic and nanoscale gold particles less than 5 μm were only found in samples having a low gold content (〈10ng/g).This result shows that geochemical provinces,delineated by a threshold value of 2.5 ng/g,are formed by long-distance transport of ultrafine gold in streams.The findings may provide direct microscopic evidence for gold migration to form geochemical provinces. 展开更多
关键词 GOLD Geochemical provinces Formation Mechanism Microscopic particles nanoscaleparticles
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Mineral provinces and material provenance of the surficial sediments near the Zhongsha Islands in the South China Sea 被引量:5
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作者 YAN Quanshu SHI Xuefa WANG Kunshan 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2007年第1期66-76,共11页
Characteristics and distribution patterns of clastic minerals (0. 063 -0. 125 mm) in bottom sediments represent a significant indi- cator for the identification of the origin of sediment. One hundred and fourteen su... Characteristics and distribution patterns of clastic minerals (0. 063 -0. 125 mm) in bottom sediments represent a significant indi- cator for the identification of the origin of sediment. One hundred and fourteen surface sediment samples, which were collected from the area near the Zhongsha Islands in the South China Sea, were analysed to identify the mineral suites and their distributions in the study area. The area can be divided into three mineral provinces : (Ⅰ) a province of biogenic minerals, which mainly originate from the Zhongsha Atoll ; ( Ⅱ) a province of volcanogenic minerals, which are mainly derived from local basaltic seamounts and small-scale volcanoes that are probably erupting, with some influences from the island-arc volcanic region around the South China Sea; and ( Ⅲ) a mixed mineral province whose material source includes biogenic minerals, volcanogenic minerals and terrigenous minerals; the last province can be subdivided into a mixed mineral sub-province of the northeastern part of the study area, in which terrigenous minerals are mainly derived from China' s Mainland and do not exceed 17°N, and a mixed mineral subprovince of the southeastern part of the study area, in which terrigenous minerals are derived from Kalimantan and Indochina Peninsula and might be further transported into the deep sea basin through submarine canyons. 展开更多
关键词 South China Sea Zhongsha Islands light mineral minerals province material provenance
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Phytoplankton Species Composition of Four Ecological Provinces in Yellow Sea, China 被引量:2
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作者 LI Xiaoqian FENG Yuanyuan +2 位作者 LENG Xiaoyun LIU Haijiao SUN Jun 《Journal of Ocean University of China》 SCIE CAS CSCD 2017年第6期1115-1125,共11页
The ecological province based on phytoplankton species composition is important to understanding the interplay between environmental parameters and phytoplankton species composition. The aim of this study was to estab... The ecological province based on phytoplankton species composition is important to understanding the interplay between environmental parameters and phytoplankton species composition. The aim of this study was to establish phytoplankton species composition ecological pattern thus elucidate the relationship between environmental factors and the phytoplankton species composition in the ecological provinces. Phytoplankton samples were collected from 31 stations in Yellow Sea(121.00?–125.00?E, 32.00?–39.22?N) in November 2014. The samples were enumerated and identified with the Uterm?hl method under an optical inverted microscope-AE2000 with magnifications of 200 × or 400 ×. In the present study, a total of 141 taxa belonging to 60 genera of 4 phyla of phytoplankton were identified, among them 101 species of 45 genera were Bacillariophyta, 36 species of 11 genera were Dinophyta, 3 species of 3 genera were Chrysophyta and 1 species of 1 genera was Chlorophyta. The study area was divided into 4 ecological provinces according to an unsupervised cluster algorithm applied to the phytoplankton biomass. A T-S(Temperature-Salinity) scatter diagram depicted with data of water temperature and salinity defined by environmental provinces matched well with the ecological provinces. The results of Canonical Correspondence Analysis(CCA) indicated that the phytoplankton species composition was mainly correlated with temperature, salinity and silicate concentration in the studied area. A method of establishing ecological provinces is useful to further understanding the environmental effects on the marine phytoplankton species composition and the consequent marine biogeochemistry. 展开更多
关键词 PHYTOPLANKTON YELLOW Sea ECOLOGICAL provincE species composition environmental parameter
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Uranium Provinces in China 被引量:7
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作者 CHEN Zhaobo ZHAO Fengmin +1 位作者 XIANG Weidong CHEN Yuehui 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2000年第3期587-594,共8页
Three uranium provinces are recognized in China, the Southeast China uranium province, the Northeast China-Inner Mongolia uranium province and the Northwest China (Xinjiang) uranium province. The latter two promise go... Three uranium provinces are recognized in China, the Southeast China uranium province, the Northeast China-Inner Mongolia uranium province and the Northwest China (Xinjiang) uranium province. The latter two promise good potential for uranium resources and are major exploration target areas in recent years. There are two major types of uranium deposits: the Phanerozoic hydrothermal type (vein type) and the Meso-Cenozoic sandstone type in different proportions in the three uranium provinces. The most important reason or prerequisite for the formation of these uranium provinces is that Precambrian uranium-enriched old basement or its broken parts (median massifs) exists or once existed in these regions, and underwent strong tectonomagmatic activation during Phanerozoic time. Uranium was mobilized from the old basement and migrated upwards to the upper structural level together with the acidic magma originating from anatexis and the primary fluids, which were then mixed with meteoric water and resulted in the formation of Phanerozoic hydrothermal uranium deposits under extensional tectonic environments. Erosion of uraniferous rocks and pre-existing uranium deposits during the Meso-Cenozoic brought about the removal of uranium into young sedimentary basins. When those basins were uplifted and slightly deformed by later tectonic activity, roll-type uranium deposits were formed as a result of redox in permeable sandstone strata. 展开更多
关键词 uranium province Phanerozoic hydrothermal(vein-type)uranium deposit Meso-Cenozoic sandstone-type uranium deposit genesis of uranium province
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Ecological provinces of spring phytoplankton in the Yellow Sea:species composition 被引量:7
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作者 ZHANG Shan LENG Xiaoyun +5 位作者 FENG Yuanyuan DING Changlin YANG Yang WANG Jing WANG Houjie SUN Jun 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第8期114-125,共12页
Phytoplanktonic ecological provinces of the Yellow Sea(31.20°–39.23°N, 121.00°–125.16°E) is derived in terms of species composition and hydrological factors(temperature and salinity). 173 sam... Phytoplanktonic ecological provinces of the Yellow Sea(31.20°–39.23°N, 121.00°–125.16°E) is derived in terms of species composition and hydrological factors(temperature and salinity). 173 samples were collected from 40 stations from April 28 to May 18, 2014, and a total of 185 phytoplanktonic algal species belonging to 81 genera of 7phyla were identified by Uterm?hl method. Phytoplankton abundance in surface waters is concentrated in the west coast of Korean Peninsula and Korea Bay, and communities in those areas are mainly composed of diatoms and cyanobacteria with dominant species of Cylindrotheca closterium, Synechocystis pevalekii, Chroomonas acuta,Paralia sulcata, Thalassiosira pacifica and Karenia mikimotoi, etc. The first ten dominant species of the investigation area are analyzed by multidimensional scaling(MDS) and cluster analysis, then the Yellow Sea is divided into five provinces from Province I(P-I) to Province V(P-V). P-I includes the coastal areas near southern Liaodong Peninsula, with phytoplankton abundance of 35 420×10^3–36 163×10^3 cells/L and an average of 35 791×10~3 cells/L, and 99.84% of biomass is contributed by cyanobacteria. P-II is from Shandong Peninsula to Subei coastal area. Phytoplankton abundance is in a range of 2×10^3–48×10^3 cells/L with an average of 24×10^3cells/L, and 63.69% of biomass is contributed by diatoms. P-III represents the Changjiang(Yangtze River) Diluted Water. Phytoplankton abundance is 10×10^3–37×10^3 cells/L with an average of 24×10^3 cells/L, and 73.14% of biomass is contributed by diatoms. P-IV represents the area affected by the Yellow Sea Warm Current.Phytoplankton abundance ranges from 6×10^3 to 82×10^3 cells/L with an average of 28×10^3 cells/L, and 64.17% of biomass is contributed by diatoms. P-V represents the cold water mass of northern Yellow Sea. Phytoplankton abundance is in a range of 41×10^3–8 912×10^3 cells/L with an average of 1 763×10^3 cells/L, and 89.96% of biomass is contributed by diatoms. Overall, structures of phytoplankton community in spring are quite heterogeneous in different provinces. Canonical correspondence analysis(CCA) result illustrates the relationship between dominant species and environmental factors, and demonstrates that the main environmental factors that affect phytoplankton distribution are nitrate, temperature and salinity. 展开更多
关键词 phytoplankton ecological province Yellow Sea spring
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Mineral provinces and matter provenance of the surficial sediments in the western Philippine Sea:implication for modern sedimentation in West Pacific marginal basin 被引量:2
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作者 REN Xiangwen YAN Quanshu +2 位作者 SHI Xuefa WANG Kunshan JIANG Xiaoli 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2007年第3期44-55,共12页
The characteristics and distribution patterns of detrital minerals (0. 063 -0. 125 mm) in marine sediments provide a significant indicator for the identification of the origin of sediment. The detrital mineral compo... The characteristics and distribution patterns of detrital minerals (0. 063 -0. 125 mm) in marine sediments provide a significant indicator for the identification of the origin of sediment. The detrital mineral composition of 219 surface sediment samples was ana- lysed to identify the distribution of sediments within the western Philippine Sea. The area can be divided into three mineral provinces : (Ⅰ) province east of the Philippine Trench, the detrital minerals in this province are mainly composed of calcareous or siliceous organisms, with the addition of volcanogenic minerals from an adjacent island arc; (Ⅱ) middle mineral province, clastic minerals including feldspar, quartz and colorless volcanic glass, sourced from seamounts with intermediate-acid volcanic rock, or erupting intermediate-acid volcano; (Ⅲ) province west of the Palau--Kyushu Ridge, the matter provenance within this province is complex; the small quantity of feldspar and quartz may be sourced from seamounts or erupting volcano with intermediate - acid composition, with a component of volcanic scoria sourced from a volcano erupting on the Palau--Kyushu Ridge. it is suggested that, ( 1 ) Biogenic debris of the study area is closely related to water depth, with the amount of biogenic debris controlled by carbonate lysocline. (2) Volcaniclastic matter derived from the adjacent island arc can be entrained by oceanic currents and transported towards the abyssal basin over a short distance. The weathering products of volcanic rocks of the submarine plateau (e. g. , Benham Plateau) and adjacent ridges provide an important source of detrital sedimentation, and the influence scope of them is constrained by the intensity of submarine weathering. (3) Terrigenous sediments from the continent of Asia and the adjacent Philippine island arc have little influence on the sedimentation of this study area, and the felsic mineral component is probably sourced from volcanic seamounts of intermediate-acid composition. 展开更多
关键词 light mineral mineral province matter provenance western Philippine Sea
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Study of Noble Metal Elements in Lower Cambrian Black Rock Series of Guizhou-Hunan Provinces, China 被引量:2
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作者 Li Shengrong Department of Geology and Mineral Resources, China University of Geosciences, Beijing 100083 Gao Zhenmin Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002 《Journal of Earth Science》 SCIE CAS CSCD 1999年第1期93-96,共4页
Systematic analyses of noble metal elements in the Lower Cambrian black rock series of South China are reported. Correlations of w (Os)/ w (Ir), w (Au)/ w (Ir), w (Ag)/ w (Au), w (Pt+Pd)/ w (Os+R... Systematic analyses of noble metal elements in the Lower Cambrian black rock series of South China are reported. Correlations of w (Os)/ w (Ir), w (Au)/ w (Ir), w (Ag)/ w (Au), w (Pt+Pd)/ w (Os+Ru+Rh+Ir), relations of noble metal and platinum group element (PGE) distribution patterns reveal that the noble metals are not directly from extraterrestrial materials. Studying the data of 9 aspects, the authors conclude that the noble metals were mainly from ultramafic mafic igneous rocks and their enrichment in black rocks is mainly controlled by hydrothermal fluid. 展开更多
关键词 black shale Au Ag PGE Lower Cambrian Guizhou Hunan provinces China.
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EMERGY ANALYSIS OF GRAIN PRODUCTION SYSTEM IN JIANGSU AND SHAANXI PROVINCES 被引量:2
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作者 LIUXin-wei CHENBai-ming ZHANGDing-xiang 《Chinese Geographical Science》 SCIE CSCD 2004年第3期209-214,共6页
Efficiency and sustainability of grain production are now important in China. In this study, the grain production systems of Jiangsu and Shaanxi Provinces were compared, to analyze their efficiency and sustainability ... Efficiency and sustainability of grain production are now important in China. In this study, the grain production systems of Jiangsu and Shaanxi Provinces were compared, to analyze their efficiency and sustainability in terms of utilization of natural resources, inputs of purchased energy and materials, and outputs. Flows of energy and materials between environment and human society were identified, and the natural and human work involved in generating inputs as materials or energy were valued in terms of equivalent amount of solar energy required for their production using emergy method. The results showed environmental resources were continually playing a less important role in the systems, when inorganic subsidiary emergy inputs increased drastically while organic ones decreased or increased little. Deterioration of input emergy structure affected the systems′ efficiency and sustainability,resulting in emergy investment ratios and environmental loading ratios increasing while yield ratios and sustainability indices decreasing. In general, efficiency and sustainability of grain production in Jiangsu are worse than those in Shaanxi. This analysis also suggested that inorganic subsidiary emergy should be introduced properly, and peasants in Jiangsu should utilize natural conditions wisely while those in Shaanxi pay enough attention to soil and surface water conservation. 展开更多
关键词 emergy analysis grain production system Jiangsu province Shaanxi province
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Periodicities in the emplacement of large igneous provinces through the Phanerozoic:Relations to ocean chemistry and marine biodiversity evolution 被引量:8
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作者 Andreas Prokoph Hafida E1 Bilali Richard Ernst 《Geoscience Frontiers》 SCIE CAS CSCD 2013年第3期263-276,共14页
Large igneous provinces (LIPs) are considered a relevant cause for mass extinctions of marine life throughout Earth's history. Their flood basalts and associated intrusions can cause significant release of SO4 and ... Large igneous provinces (LIPs) are considered a relevant cause for mass extinctions of marine life throughout Earth's history. Their flood basalts and associated intrusions can cause significant release of SO4 and CO2 and consequently, cause major environmental disruptions. Here, we reconstruct the long-term periodic pattern of LIP emplacement and its impact on ocean chemistry and biodiversity from δ34Ssulfate of the last 520 Ma under particular consideration of the preservation limits of LIP records. A combination of cross-wavelet and other time-series analysis methods has been applied to quantify a potential chain of linkage between LIP emplacement periodicity, geochemical changes and the Phanerozoic marine genera record. We suggest a mantle plume cyclicity represented by LIP volumes (V) of V= (350-770) × 103km3sin(27πt/ 170 Ma)+ (300-650)× 103 km3 sin(2πt/64.5 Ma + 2.3) for t= time in Ma. A shift from the 64.5 Ma to a weaker -28-35 Ma LIP cyclicity during the Jurassic contributes together with probably independent changes in the marine sulfur cycle to less ocean anoxia, and a general stabilization of ocean chemistry and increasing marine biodiversity throughout the last -135 Ma. The LIP cycle pattern is coherent with marine biodiversity fluctuations corresponding to a reduction of marine biodiversity of -120 genera/Ma at 600 x 103 km3 LIP eruption volume. The 62-65 Ma LIP cycle pattern as well as excursion in -34Ssulfate and marine genera reduction suggest a not-vet identified found LIP event at - 440-450 Ma. 展开更多
关键词 Large igneous provinces Wavelet transform Sulfur isotope Mantle plume Marine biodiversity Periodicity
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From Provincialism to Metropolitanism:Social Mobility in English and American Novels of “the Young Man from the Provinces"
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作者 孙胜忠 《英美文学研究论丛》 CSSCI 2018年第1期155-171,共17页
基于莱昂内尔·特里林对"外省青年"的界定,本文指出再现主人公从小地方向大都市流动是19世纪以来英美小说中反复出现的主题。这种流动或生命之旅不仅仅是生活和职业上地理位置的迁移或变化,它反映的是"外省青年"在身体或精神层... 基于莱昂内尔·特里林对"外省青年"的界定,本文指出再现主人公从小地方向大都市流动是19世纪以来英美小说中反复出现的主题。这种流动或生命之旅不仅仅是生活和职业上地理位置的迁移或变化,它反映的是"外省青年"在身体或精神层面向上的社会流动。但在描写这一类似的向上流动的趋势背后,英美小说所揭示出的流动动机和表现却大相径庭,即便在同一国度属于不同历史时期的小说中它们也迥然有别。19世纪中叶的英国小说呈现的是主人公社会实用主义自我教育形式的社会流动,而美国此类小说别具一格地描写的是主人公对美国梦的追寻,更确切地说,是他们的幻灭。19和20世纪之交以来,英美这类小说倾向于再现"外省青年"的精神历险。文章最后探讨了这种由小地方向大都市流动的动因和启示。 展开更多
关键词 地方主义 都市主义 社会流动性 “外省青年” 英美小说
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Time series analysis of mantle cycles Part Ⅱ:The geologic record in zircons, large igneous provinces and mantle lithosphere 被引量:1
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作者 Kent C. Condie Stephen J. Puetz 《Geoscience Frontiers》 SCIE CAS CSCD 2019年第4期1327-1336,共10页
Igneous and detrital zircons have six major U/Pb isotopic age peaks in common(2700 Ma,1875 Ma.1045 Ma,625 Ma,265 Ma and 90 Ma).For igneous rocks,each age peak is comprised of subpeaks with distinct geographic distribu... Igneous and detrital zircons have six major U/Pb isotopic age peaks in common(2700 Ma,1875 Ma.1045 Ma,625 Ma,265 Ma and 90 Ma).For igneous rocks,each age peak is comprised of subpeaks with distinct geographic distributions and a subpeak age range per age peak≤100 Myr.There are eight major LIP age peaks(found on≥10 crustal provinces)of which only four are in common to major detrital zircon age peaks(2715 Ma,1875 Ma,825 Ma,90 Ma).Of the whole-rock Re depletion ages,58%have correspo nding detrital zircon age peaks and 55%have corresponding LIP age peaks.Ten age pea ks are fou nd in common to igneous zircon,detrital zircon,LIP,and Re depletion age time series(3225 Ma,2875 Ma,2145 Ma,2085 Ma,1985 Ma,1785 Ma,1455 Ma,1175 Ma,825 Ma,and 90 Ma).and these are very robust peaks on a global scale as recorded in both crustal and mantle rocks.About 50%of the age peaks in each of these time series correspond to predicted peaks in a 94-Myr mantle cycle,including four of the ten peaks in common to all four time series(2875 Ma,1785 Ma,825 Ma and 90 Ma).Age peak widths and subpeak ranges per age peak suggest that mantle events responsible for age peaks are<100 Myr and many<50 Myr in duration.Age peak geographic distributions show three populations(≤1000 Ma,2500-1000 Ma,>2500 Ma),with the number of new provinces in which age peaks are represented decreasing with time within each population.The breaks between the populations(at 2.5 Ga and 1 Ga)fall near the onsets of two transitions in Earth history.The First Transition may represent a change from stagnant-lid tectonics into plate tectonics and the Second Transition,the onset of subduction of continental crust.The major factor controlling geographic distribution of age peaks is the changing locations of orogeny.Before^2 Ga,age subpeaks and peaks are housed in orogens within or around the edges of crustal provinces,mostly in accretionary orogens.but beginning at 1.9 Ga,collisional orogens become more important.The coincidence in duration between magmatic flare-ups in Phanerozoic arcs and duration of age subpeaks(10-30 Myr)is consiste nt with subpeaks representing periods of enhanced arcrelated magmatism.probably caused by increased subduction flux.The correlation of isotopic age peaks between time series supports a cause and effect relationship between mantle plume activity,continental magma production at convergent margins,and crustal deformation.Correlation of over half of the detrital zircon age peaks(and six of the nine major peaks)with Re depletion age peaks supports an interpretation of the zircon peaks as crustal growth rather than selective preservation peaks. 展开更多
关键词 Isotopic age PEAKS U/Pb zircon AGES Re depletion AGES Large IGNEOUS provinces Age peak correlation MANTLE cycles
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Rhyolites in continental mafic Large Igneous Provinces: Petrology,geochemistry and petrogenesis 被引量:1
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作者 Mahesh Halder Debajyoti Paul Sarajit Sensarma 《Geoscience Frontiers》 SCIE CAS CSCD 2021年第1期53-80,共28页
We present a detailed review of the petrological and geochemical aspects of rhyolite and associated silicic volcanic rocks(up to 20 vol%of all rocks)reported to date from twelve well known Phanerozoic continental mafi... We present a detailed review of the petrological and geochemical aspects of rhyolite and associated silicic volcanic rocks(up to 20 vol%of all rocks)reported to date from twelve well known Phanerozoic continental mafic Large Igneous Provinces(LIPs).These typically spread over<104 km^2(rarely 105 km^2 for Parana-Etendeka)area and comprise<10~4 km^3 of extrusive silicic rocks,erupted either during or after the main basaltic eruption within<5 Myr,with some eruption(s)continuing for≤30 Myr.These rhyolites and associated silicic volcanic rocks(60-81 wt.%of SiO2)are mostly metaluminous to peraluminous and are formed via(ⅰ)fractional crystallization of parental mafic magma with negligible crustal contamination,and(ⅱ)melting of continental crust or assimilation and fractional crystallization(AFC)of mafic magma with significant crustal contribution.Rhyolites formed by extensive fractional crystallization are characterized by the presence of clinopyroxene phenocrysts,exhibit steep negative slopes in bivariate major oxides plots and weak to no Nb-Ta anomaly;these typically have temperature>900℃.Rhyolites formed by significant crustal contribution are characterized by strong negative Nb-Ta anomalies,absence of clinopyroxene phenocrysts,and are likely to have a magma temperature<900℃.Geochemical signatures suggest rhyolite melt generation in the plagioclase stability field with a minor fraction originating from lower crustal depths.A large part of the compositional variability in rhyolites,particularly the SrNd-Pb-O isotope ratios,suggests a significant role of continental crust(upper crustal melting or AFC)in the evolution of these silicic rocks in the continental mafic LIPs. 展开更多
关键词 Large Igneous province Silicic rock RHYOLITE GEOCHEMISTRY PETROGENESIS AFC
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The Research on the Current Situation of English Interpreting Studies in Three Northeastern Provinces of China
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作者 刘璇 徐畔 《海外英语》 2015年第2期169-170,203,共3页
Since the Master of Translation and Interpreting has been established under the approval of the Academic Degrees Committee of the State Council and the Chinese Ministry of Education, translation discipline stepped int... Since the Master of Translation and Interpreting has been established under the approval of the Academic Degrees Committee of the State Council and the Chinese Ministry of Education, translation discipline stepped into a rapid development period in China as well as the research of interpreting studies. This paper aimed at providing a brief introduction of the current situation and existing problems of English interpreting studies in Three Northeastern Provinces of China under the comparative analysis of literature in CNKI China Academic Journal Network Publishing Database from 2004 to 2013. 展开更多
关键词 THREE NORTHEASTERN provinces of China ENGLISH INTERPRETING studies current SITUATION
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The Forming Mechanisms of the Neoproterozoic Molartooth Carbonatites in North Anhui and Jiangsu Provinces
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作者 Zhihai Jia,Liwei Zhang School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009,China. 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期260-260,共1页
As a characteristic sedimentary type,molartooth carbonatites veins(MCV) can be found in almost all the Neoproterozoic carbonatite strata in the North Anhui and Jiangsu Provinces.But their forming mechanism is still an... As a characteristic sedimentary type,molartooth carbonatites veins(MCV) can be found in almost all the Neoproterozoic carbonatite strata in the North Anhui and Jiangsu Provinces.But their forming mechanism is still an enigma,and more than four incompatible forming hypotheses have been put forward according to the structures,mineral components and elements of the MCV.Though all the MCV with the similar shape 展开更多
关键词 molartooth CARBONATITES NEOPROTEROZOIC forming mechanism NORTH ANHUI and Jiangsu provinces
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关联理论视角下来华游记The Provinces of Western China的汉译研究
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作者 杨军燕 何泠静 《英语广场(学术研究)》 2021年第18期40-42,共3页
英国传教士普鲁恩夫人于1906年撰写了来华游记The Provinces of Western China,记叙晚清时期作者及其家人在华西诸省的所见所闻,这一游记对于我们了解当时四川、重庆、云南、贵州等地的风土人情具有重要价值。目前国内外学者对The Provi... 英国传教士普鲁恩夫人于1906年撰写了来华游记The Provinces of Western China,记叙晚清时期作者及其家人在华西诸省的所见所闻,这一游记对于我们了解当时四川、重庆、云南、贵州等地的风土人情具有重要价值。目前国内外学者对The Provinces of Western China所做的翻译研究不多。因此,文章拟以关联理论为指导,从词汇、句子两个层面分析来华游记The Provinces of Western China中的汉译实例,从而总结关联理论,希望对来华游记汉译具有指导意义。 展开更多
关键词 关联理论 来华游记 The provinces of Western China 汉译研究
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ENVIRONMENTAL FEATURES AND WATERENVIRONMENTAL PROBLEMS IN THE CONTIGUOUSREGION OF JIANGSU,SHANGDONG,HENANAND ANHUI PROVINCES
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作者 季子修 于秀波 张琛 《Chinese Geographical Science》 SCIE CSCD 1999年第1期63-69,共7页
Owing to intensive human activities and the floods of the Huaihe River in historic peiod, the contiguous region of Jiangsu, Shandong, Henan and Anhui provinces is suffering from a variety of environmental problems and... Owing to intensive human activities and the floods of the Huaihe River in historic peiod, the contiguous region of Jiangsu, Shandong, Henan and Anhui provinces is suffering from a variety of environmental problems and naturaldisasters, of which water pollution and drought-flood disasters are most observable. Considering the special location andenvironmental status of the contiguous region, advices are proposed in the paper: perfecting trans-regional managementssystem of water environment incorporating basin management agencies in local government activities; strengthening cooperation of two agencies: water conservancy agency and environment protection agency; enhancing integrated control ofwater pollution and flood-drought disasters; taking the interests of the whole river into acount and paying attention to bothstorage and drainage; broadening sources of water supply and inceasing water delivery; controlling pollutant discharge,developing water saving production system. 展开更多
关键词 environmental problems drought and flood DISASTERS WATER pollution contiguous region of Jiangsu Shandong HENAN and ANHUI provinces
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A New Species of <i>Gentiana, Gentiana ciliolata</i>and It’s Two Subspecies of subsp. ciliolata and subsp. <i>longiloba</i>of Yunnan &Sichuan Provinces
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作者 Shaoyong Yang Haifeng Cao +3 位作者 Fan Du Juan Wang Qiaorong Zhang Wen-Tsai Wang 《American Journal of Plant Sciences》 2020年第7期1137-1143,共7页
A new species of </span><i><span style="font-family:Verdana;">Gentiana</span></i><span style="font-family:Verdana;"> (</span><i><span style="... A new species of </span><i><span style="font-family:Verdana;">Gentiana</span></i><span style="font-family:Verdana;"> (</span><i><span style="font-family:Verdana;">Gentianaceae</span></i><span style="font-family:Verdana;">), </span><i><span style="font-family:Verdana;">Gentiana</span></i> <i><span style="font-family:Verdana;">ciliolata</span></i> <span style="font-family:Verdana;">is</span><span style="font-family:Verdana;"> described and illustrated;it has a spectacular characteristics of calyx lobe ciliolate, distributed in Yunnan and Sichuan Provinces on the two sides of Jinsha River, and then two subspecies have been further re-classified as </span><i><span style="font-family:Verdana;">Gentiana</span></i> <i><span style="font-family:Verdana;">ciliolata</span></i> <span style="font-family:Verdana;">subsp</span><i><span style="font-family:Verdana;">.</span></i> <i><span style="font-family:Verdana;">ciliolata</span></i> <span style="font-family:Verdana;">and </span><i><span style="font-family:Verdana;">Gentiana</span></i> <i><span style="font-family:Verdana;">ciliolata</span></i> <span style="font-family:Verdana;">subsp.</span> <i><span style="font-family:Verdana;">longiloba</span></i> <span style="font-family:Verdana;">respectively</span><i><span style="font-family:Verdana;">.</span></i> <span style="font-family:Verdana;">The subsp.</span> <i><span style="font-family:Verdana;">ciliolata</span></i><span style="font-family:Verdana;"> idistributes</span> <span style="font-family:Verdana;">on the right side of Jinsha River in Yiliang County, Yunnan Province and the subsp</span><i><span style="font-family:Verdana;">.</span></i> <i><span style="font-family:Verdana;">longiloba</span></i><span style="font-family:Verdana;"> distributes itself </span><span style="font-family:Verdana;">on the southwest and west part of Sichuan Province, such as Leibo County, Wenchuan County and Mabian Yi Autonomous Prefacture, in the grassland under forests and moist rock slopes at an altitude of 1300 - 3200 m. 展开更多
关键词 New Species Gentiana ciliolate subsp. ciliolate subsp. longiloba Yiliang County Leibo County Jinsha River Yunnan province Sichuan province
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Spatial Assessment of Water Quantity Stress in Sultanate of Oman Provinces: A GIS Based Analysis of Water Resources Variability
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作者 Talal Al-Awadhi Shawky Mansour 《Journal of Geographic Information System》 2015年第6期565-578,共14页
Water quantity planning and management require understanding of spatial variations of water catchment availability. Several environmental indicators are associated with water quantity such as flood occurrence, drought... Water quantity planning and management require understanding of spatial variations of water catchment availability. Several environmental indicators are associated with water quantity such as flood occurrence, drought severity, seasonal supply and groundwater stress. Analyzing water stress at national geographic scale is crucial to detect and explore geographic shortage of water resources at national scale. In this study, Geographical Information Systems (GIS) techniques were employed to analyze the spatial variations of water scarcity across Sultanate of Oman provinces. For this main objective, various spatial and attribute datasets were prepared. Many variables were selected based on their importance and correlation with water quantity. GIS overlay function then was used to produce maps for each water indicator. This was followed by employing raster zonal statistics to aggregate the values of each catchment area within each province. The findings of this analysis indicated that significant spatial variation was found among Omani provinces in terms of water quantity stress and its determinants. The most important factors affecting the water quantity stress were drought severity and flood occurrence. Furthermore, physical risk of water quantity was higher in Mascut and Dhofar provinces while it was moderate in Al-Batinah, A’Dakhiliyah and Al-Wusta. Lower risk of water quantity was observed in A’Sharqiyah, Masandam, and A’Dhahriah provinces. Thus, in order to mitigate the impacts of water scarcity on agriculture, cultivation and domestic usages, policy makers in water sector should include spatial strategies for water resource maintain and allocation. 展开更多
关键词 GIS SPATIAL ASSESSMENT Water Quantity Omani provinces
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