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1.
A synthesis of Holocene pollen records from the Tibetan Plateau shows the history of vegetation and climatic changes during the Holocene. Palynological evidences from 24 cores/sections have been compiled and show that the vegetation shifted from subalpine/alpine conifer forest to subalpine/alpine evergreen sclerophyllous forest in the southeastern part of the plateau; from alpine steppe to alpine desert in the central, western and northern part; and from alpine meadow to alpine steppe in the eastern and southern plateau regions during the Holocene. These records show that increases in precipitation began about 9 ka from the southeast, and a wide ranging level of increased humidity developed over the entire of the plateau around 8-7 ka, followed by aridity from 6 ka and a continuous drying over the plateau after 4-3 ka. The changes in Holocene climates of the plateau can be interpreted qualitatively as a response to orbital forcing and its secondary effects on the Indian Monsoon which expanded northwards 相似文献
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I.IntroductionThroughouthistorymineralshavebeenadeterminantfactorintheevolutionofsocietiesandcivilization.TheveryobviousimpactofmineralsonMan’sevolutioncanbetracedintermsofMan’sacquaintancewithminerals—thePrestoneAge,theStoneAge,theBronzeAge,theIronAge,… 相似文献
4.
Lin Junshu Li Juzhang Fang Jinfu Institute of Geography CAS Beijing People''s Republic of China 《地理学报(英文版)》1997,(3)
IntroductionSolutionasakarstgeomorphologicalprocessinlandformdevelopmenthaslongbeenrecognized.Sincethekarstprocessesarealmostentirelysolution,thoughkarstlandformsarenotonlycausedbysolutionbutalsobyerosion,thecirculationandchemicalcompositionsofkarstun… 相似文献
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Chen Jianyao Wu Kai Institute of Geography CAS Beijing People''s Republic of China 《地理学报(英文版)》1997,(3)
I.IntroductionTheHuang-Huai-HaiPlaininNorthChinaisacrucialareainprovidingaboutone-fifthoftotalstatefood[4],anditisfacingaseriouswatershortageinrecentyearsduetotheexpansionofindustryandacontinuousdecreaseinprecipitation.Thestudyinsoil-plant-atmosphereconti… 相似文献
6.
DYNAMIC VARIATIONS OF WATER QUALITY IN TAIHU LAKE AND MULTIVARIATE ANALYSIS OF ITS INFLUENTIAL FACTORS 总被引:1,自引:0,他引:1
Cai Qiming Gao Xiyun Chen Yuwei Ma Shengwei Nanjing Institute of Geography Limnology CAS Nanjing People''s Republic of ChinaMartin Dokulil Institute of Limnology Austria 《地理学报(英文版)》1997,(3)
LakeTaihuisalargeshallowlakeinChina,whichpalysanimportantroleinwater-quantityregulation,watersupply,cultivationetc.Withrapiddevelopmentofagricultureandindustryinthearea,alargenumberofpollutantshavebeendischargedintothelake,leadingtoanincreaseinnutrients… 相似文献
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Leng Shuying Zheng Du Institute of Geography CAS Beijing People''s Republic of China 《地理学报(英文版)》1997,(4)
I.LandDegradationDistributionandItsCharacteristicsThefarmingpastoraltransitionalregioninsemiaridlandofnorthernChinaisthemosttypicalregionoflanddegradation,andalsotheregionwithextensivelydevelopingsandydesertification.TheextentisfromHorqinSandyLandinth… 相似文献
8.
References: 《东北亚地学研究》2008,11(1):25-31
Dexing copper deposit is the biggest porphyry copper deposit in China. By researching isotopes of C, Si and Cu from the samples of Tongchang and Fujiawu ore-field, the authors found that δ^13 CpDB values of siderite were close to the δ^13 CpDB value of original magma; δ^30Si values of the samples at the ore-forming stage were close to the δ^30 Si value range of magma, δ^30Si values of partial samples were far away from it; Cu isotopic compositions of massive chalcopyrite formed at the early ore-forming stage are higher than that of veinal chalcopyrite formed at the later ore-forming stage. The results show that ore-forming materials were mainly derived from the porphyry body, and part of them were from wall rock materials. 相似文献
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The Yangtze Estuary, the largest estuary in China, is under an obvious interaction between runoff and astronomical tide. The research on the interaction is very important for the exploitation and utilization of water resources in this area. A horizontal 2D hydrodynamic numerical model is established and verified in the present study with the modeling range from Datong to the Yangtze Estuary. Based on the comparison of high water levels under the interaction between different runoff and estuarine dynamics, s... 相似文献
10.
NUMERICAL EXPERIMENT OF THE INFLUENCES OF HEAT AND WIND STRESS ON THE EQUATORIAL OCEAN CIRCULATION 总被引:1,自引:0,他引:1
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A time-dependent linear model on the equatorial beta plane is developed in this paper.Its verticalstructure consists of two active layers with equal density and temperature above the thermocline and aquasi-stationary layer with constant density below the thermocline.The results of nurnericat experiments show that the direct influence of heat on the equatorial ocean ismuch smaller than that of wind stress.Nevertheless,through the tropical ocean-atmosphere interaction,the change of wind stress resulting from the thermal forcing may set a determinant effect on the equilibriumand anomalous development of the ocean-almosphere circulation. 相似文献