Feiyan Shoal is a sub Yellow River Delta, which was formed from Jan. 1964 to May 1976, when the Yellow River entered sea via Diaokou Channel. Since the terminal reach shifted to Qingshuigou channel in 1976, Feiyan Sho...Feiyan Shoal is a sub Yellow River Delta, which was formed from Jan. 1964 to May 1976, when the Yellow River entered sea via Diaokou Channel. Since the terminal reach shifted to Qingshuigou channel in 1976, Feiyan Shoal has been experiencing severe erosion and retreat. This paper explains the evolutionary characteristics of the typical profile of Feiyan Shoal from the perspective of dynamical force and sediments＇ characteristics. All this is on the basis of the data of topographic profiles observed since the 1970s and the samples of hydrology and sediments collected in situ in Apr. 2004, the analysis of the retreating distance, and the tidal and wave friction velocity distribution. Feiyan Shoal topographical profile has experienced a course of ＂fast erosion and retrogression - slow eroding modulation - fluctuate triggering change＂ in recent 30 years, which is also the gradual disappearing process of the delta front. The different intensity of sediment erosion resistance is the main reason for the erosion speed changes. Due to the hydrodynamic force changes, the water depth range of maximum retreating distance and between erosion and progradation became shallow. It indicates that the storm tide will still be the triggering force of seashore topographic profile evolutions in the future.展开更多
The alkali-rich rocks, spreading along the suture zone of Jingsha River, refer to the alkali-rich porphyry rocks, which emplace during the Himalaya epoch in northwest of Yunnan Province, and consist of syenit, syenit ...The alkali-rich rocks, spreading along the suture zone of Jingsha River, refer to the alkali-rich porphyry rocks, which emplace during the Himalaya epoch in northwest of Yunnan Province, and consist of syenit, syenit porphyry, monzonite porphyry and granite porphyry. Petrological chemical analysis results suggest that silica is poor and aluminum is rich, and high potassium large ion lithophile elements （LILE）, light rare earth element （LREE） and Sr are obviously detracted in these rocks. High field strength elements （HFSE） and heavy rare earth element （HREE） are depleted, especially Nb, Ta, P and Ti. 8Eu： 0.09--1.64 shows that plagioclase does not appear fractional crystallization during the formation of alkali-rich rocks, t^348, H and O isotopes and Pb isotopes suggest that ore-forming fluid is derived from the mantle, and Pb is possibly mixed by mantle, wall rock and crust. The age of Pb in alkali-rich rocks is about 250-220 Ma. The age of alkali porphyry rock （dykes） varies from 30 Ma to 50 Ma. Alkali rocks have strong metallogenetic relation. Au mineralization is associated to the alkali magrnatic activities with a relatively high temperature, low pressure and high oxygen fugacity. However, copper mineralization is mainly associated with alkali-sub-alkali magmatic activities in a process of relatively low temperature, high pressure and lower oxygen fugacity.展开更多
A Local Ensemble Transform Kalman Filter assimilation system has been implemented into an aerosol-coupled global nonhydrostatic model to simulate the aerosol mass concentration and aerosol optical properties of 3 dese...A Local Ensemble Transform Kalman Filter assimilation system has been implemented into an aerosol-coupled global nonhydrostatic model to simulate the aerosol mass concentration and aerosol optical properties of 3 desert sites(Ansai, Fukang, Shapotou) in northwestern China. One-month experiment results of April 2006 reveal that the data assimilation can correct the much overestimated aerosol surface mass concentration, and has a strong positive effect on the aerosol optical depth(AOD) simulation, improving agreement with observations. Improvement is limited with the?ngstr€om Exponent(AE) simulation, except for much improved correlation coefficient and model skill scores over the Ansai site. Better agreement of the AOD spatial distribution with the independent observations of Terra(Deep Blue) and Multi-angle Imaging Spectroradiometer(MISR) AODs is obtained by assimilating the Moderate Resolution Imaging Spectroradiometer(MODIS) AOD product, especially for regions with AODs lower than 0.30. This study confirms the usefulness of the remote sensing observations for the improvement of global aerosol modeling.展开更多
The composition of single-grain detrital zircons is an effective provenance indicator of loess,and sheds new light on dust formation and transportation.Here we review the features of detrital zircons and their use as ...The composition of single-grain detrital zircons is an effective provenance indicator of loess,and sheds new light on dust formation and transportation.Here we review the features of detrital zircons and their use as a provenance indicator,including internal structure,trace element,U-Pb age spectrum and Hf isotopic compositions,and present a case study from the Horqin sandy land and its surrounding loess.The loess samples have detrital zircon age peaks in range of 2600-2300,2100-1600,and 600-100 Ma,of which the 2600-2300 Ma zircon grains mainly have positive Hf(t) values(3.4-8.7),the 2100-1600 Ma zircon grains mainly have negative Hf(t) values(10.1-6.8),and the 600-100 Ma zircon grains have a variable Hf(t) values ranging from 21 to 15.9.The detrital zircon signatures of the loess are similar to the Horqin sandy land,but clearly different from the Chinese Loess Plateau and central-western deserts,implying that the loess is transported mainly from the Horqin sandy land in the Last Glacial period.Comparing these with neighboring tectonic units,we found that zircon populations at 2600-2300,2100-1600,and 600-100 Ma with negative Hf(t) values may come from the northeast North China Craton(NCC),and those at 600-100 Ma with positive Hf(t) values may come from the east Central Asian Orogenic Belt(CAOB).It is estimated that the two sources contribute equally to the Horqin sandy land and the surrounding loess.展开更多
Aims In plant eco-physiology,less negative(enriched)carbon 13(^(13)C)in the leaves indicates conditions of reducing leaf gas exchange through stomata,e.g.under drought.In addition,^(13)C is expected to be less negativ...Aims In plant eco-physiology,less negative(enriched)carbon 13(^(13)C)in the leaves indicates conditions of reducing leaf gas exchange through stomata,e.g.under drought.In addition,^(13)C is expected to be less negative in non-photosynthetic tissues as compared with leaves.However,these relationships inδ^(13)C from leaves(photosynthetic organs)to branches,stems and roots(non-photosynthetic organs)are rarely tested across multiple closely related tree species,multiple compartments,or in trees growing under extreme heat and drought.Methods We measured leaf-to-root^(13)C in three closely related desert acacia species(Acacia tortilis,A.raddiana and A.pachyceras).We measuredδ^(13)C in leaf tissues from mature trees in southern Israel.In parallel,a 7-year irrigation experiment with 0.5,1.0 or 4.0 L day1 was conducted in an experimental orchard.At the end of the experiment,growth parameters andδ^(13)C were measured in leaves,branches,stems and roots.Important Findings Theδ^(13)C in leaf tissues sampled from mature trees was ca.-27‰,far more depleted than expected from a desert tree growing in one of the Earth's driest and hottest environments.Across acacia species and compartments,δ^(13)C was not enriched at all irrigation levels(-28‰to ca.-27‰),confirming our measurements in the mature trees.Among compartments,leafδ^(13)C was unexpectedly similar to branch and rootδ^(13)C,and surprisingly,even less negative than stemδ^(13)C.The highly depleted leafδ^(13)C suggests that these trees have high stomatai gas exchange,despite growing in extremely dry habitats.The lack ofδ^(13)C enrichment in nonphotosynthetic tissues might be related to the seasonal coupling of growth of leaves and heterotrophic tissues.展开更多
基金the Major State Basic Research Development Program of China(‘973’Program)(Grant No.2002CB412408)the Shanghai Youth Science and Technology Venus(GrantNo.06QA14016).
文摘Feiyan Shoal is a sub Yellow River Delta, which was formed from Jan. 1964 to May 1976, when the Yellow River entered sea via Diaokou Channel. Since the terminal reach shifted to Qingshuigou channel in 1976, Feiyan Shoal has been experiencing severe erosion and retreat. This paper explains the evolutionary characteristics of the typical profile of Feiyan Shoal from the perspective of dynamical force and sediments＇ characteristics. All this is on the basis of the data of topographic profiles observed since the 1970s and the samples of hydrology and sediments collected in situ in Apr. 2004, the analysis of the retreating distance, and the tidal and wave friction velocity distribution. Feiyan Shoal topographical profile has experienced a course of ＂fast erosion and retrogression - slow eroding modulation - fluctuate triggering change＂ in recent 30 years, which is also the gradual disappearing process of the delta front. The different intensity of sediment erosion resistance is the main reason for the erosion speed changes. Due to the hydrodynamic force changes, the water depth range of maximum retreating distance and between erosion and progradation became shallow. It indicates that the storm tide will still be the triggering force of seashore topographic profile evolutions in the future.
基金Project(1343-74334000019) supported by the PhD Innovation Subject of Central south University,ChinaProject(1960-71131100088 (CX2010B085)) supported by the Hunan Provincial Innovation Foundation For Postgraduate Students,China
文摘The alkali-rich rocks, spreading along the suture zone of Jingsha River, refer to the alkali-rich porphyry rocks, which emplace during the Himalaya epoch in northwest of Yunnan Province, and consist of syenit, syenit porphyry, monzonite porphyry and granite porphyry. Petrological chemical analysis results suggest that silica is poor and aluminum is rich, and high potassium large ion lithophile elements （LILE）, light rare earth element （LREE） and Sr are obviously detracted in these rocks. High field strength elements （HFSE） and heavy rare earth element （HREE） are depleted, especially Nb, Ta, P and Ti. 8Eu： 0.09--1.64 shows that plagioclase does not appear fractional crystallization during the formation of alkali-rich rocks, t^348, H and O isotopes and Pb isotopes suggest that ore-forming fluid is derived from the mantle, and Pb is possibly mixed by mantle, wall rock and crust. The age of Pb in alkali-rich rocks is about 250-220 Ma. The age of alkali porphyry rock （dykes） varies from 30 Ma to 50 Ma. Alkali rocks have strong metallogenetic relation. Au mineralization is associated to the alkali magrnatic activities with a relatively high temperature, low pressure and high oxygen fugacity. However, copper mineralization is mainly associated with alkali-sub-alkali magmatic activities in a process of relatively low temperature, high pressure and lower oxygen fugacity.
基金supported by the funds from the National Natural Science Funds of China (41475031, 41130104)the Public Meteorology Special Foundation of MOST (GYHY201406023)+1 种基金the special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(15K02ESPCP)the JAXA/Earth CARE, the MEXT/VL for Climate System Diagnostics, the MOE/Global Environment Research Fund S-12 (14426634)and A-1101, the NIES/GOSAT, theS/ NIECGER, and the MEXT/RECCA/SALSA
文摘A Local Ensemble Transform Kalman Filter assimilation system has been implemented into an aerosol-coupled global nonhydrostatic model to simulate the aerosol mass concentration and aerosol optical properties of 3 desert sites(Ansai, Fukang, Shapotou) in northwestern China. One-month experiment results of April 2006 reveal that the data assimilation can correct the much overestimated aerosol surface mass concentration, and has a strong positive effect on the aerosol optical depth(AOD) simulation, improving agreement with observations. Improvement is limited with the?ngstr€om Exponent(AE) simulation, except for much improved correlation coefficient and model skill scores over the Ansai site. Better agreement of the AOD spatial distribution with the independent observations of Terra(Deep Blue) and Multi-angle Imaging Spectroradiometer(MISR) AODs is obtained by assimilating the Moderate Resolution Imaging Spectroradiometer(MODIS) AOD product, especially for regions with AODs lower than 0.30. This study confirms the usefulness of the remote sensing observations for the improvement of global aerosol modeling.
基金supported by Young Scholars of the National Natural Science Foundation of China (Grant No.40802037)National Basic Research Program of China (Grant No.2010CB950204)Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. 80972970)
文摘The composition of single-grain detrital zircons is an effective provenance indicator of loess,and sheds new light on dust formation and transportation.Here we review the features of detrital zircons and their use as a provenance indicator,including internal structure,trace element,U-Pb age spectrum and Hf isotopic compositions,and present a case study from the Horqin sandy land and its surrounding loess.The loess samples have detrital zircon age peaks in range of 2600-2300,2100-1600,and 600-100 Ma,of which the 2600-2300 Ma zircon grains mainly have positive Hf(t) values(3.4-8.7),the 2100-1600 Ma zircon grains mainly have negative Hf(t) values(10.1-6.8),and the 600-100 Ma zircon grains have a variable Hf(t) values ranging from 21 to 15.9.The detrital zircon signatures of the loess are similar to the Horqin sandy land,but clearly different from the Chinese Loess Plateau and central-western deserts,implying that the loess is transported mainly from the Horqin sandy land in the Last Glacial period.Comparing these with neighboring tectonic units,we found that zircon populations at 2600-2300,2100-1600,and 600-100 Ma with negative Hf(t) values may come from the northeast North China Craton(NCC),and those at 600-100 Ma with positive Hf(t) values may come from the east Central Asian Orogenic Belt(CAOB).It is estimated that the two sources contribute equally to the Horqin sandy land and the surrounding loess.
基金funded by the Benoziyo Fund for the Advancement of ScienceMr and Mrs Norman Reiser,together with the Weizmann Center for New Scientists+1 种基金the Edith&Nathan Goldberg Career Development Chair.D.U.was funded by Ariovich scholarship and by the scholarship of the environmental science school of the Hebrew University.G.W.thanks the Arava Drainage Authority and the Israeli Ministry of Science and Technology(MOST)for their continued support.The study used data available through the TRY initiative on plant traits(http://www.try-db.org,data request 8968).The TRY initiative and database is hosted,developed and maintained by J.Kattge and G.Bonisch(Max Planck Institute for Biogeochemistry,Jena,Germany)TRY is currently supported by DIVERSITAS/Future Earth and the German Centre for Integrative Biodiversity Research(iDiv)Halle-Jena-Leipzig.
文摘Aims In plant eco-physiology,less negative(enriched)carbon 13(^(13)C)in the leaves indicates conditions of reducing leaf gas exchange through stomata,e.g.under drought.In addition,^(13)C is expected to be less negative in non-photosynthetic tissues as compared with leaves.However,these relationships inδ^(13)C from leaves(photosynthetic organs)to branches,stems and roots(non-photosynthetic organs)are rarely tested across multiple closely related tree species,multiple compartments,or in trees growing under extreme heat and drought.Methods We measured leaf-to-root^(13)C in three closely related desert acacia species(Acacia tortilis,A.raddiana and A.pachyceras).We measuredδ^(13)C in leaf tissues from mature trees in southern Israel.In parallel,a 7-year irrigation experiment with 0.5,1.0 or 4.0 L day1 was conducted in an experimental orchard.At the end of the experiment,growth parameters andδ^(13)C were measured in leaves,branches,stems and roots.Important Findings Theδ^(13)C in leaf tissues sampled from mature trees was ca.-27‰,far more depleted than expected from a desert tree growing in one of the Earth's driest and hottest environments.Across acacia species and compartments,δ^(13)C was not enriched at all irrigation levels(-28‰to ca.-27‰),confirming our measurements in the mature trees.Among compartments,leafδ^(13)C was unexpectedly similar to branch and rootδ^(13)C,and surprisingly,even less negative than stemδ^(13)C.The highly depleted leafδ^(13)C suggests that these trees have high stomatai gas exchange,despite growing in extremely dry habitats.The lack ofδ^(13)C enrichment in nonphotosynthetic tissues might be related to the seasonal coupling of growth of leaves and heterotrophic tissues.
