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Climate change during the last glacial period on the southeast margin of Badain Jaran Desert, Northwest China 被引量:3
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作者 FAN Xiao-lu ZHANG Xin-yi TIAN Ming-zhong 《Journal of Mountain Science》 SCIE CSCD 2019年第10期2379-2388,共10页
Reconstruction of the desert paleoclimate is important to understand the mechanisms that triggered and/or enhanced climate change.Through optically stimulated luminescence(OSL)dating,grain size,magnetic susceptibility... Reconstruction of the desert paleoclimate is important to understand the mechanisms that triggered and/or enhanced climate change.Through optically stimulated luminescence(OSL)dating,grain size,magnetic susceptibility,X-ray powder diffraction(XRD)and geochemical indicators,we provide a welldated record of a sedimentary outcrop on the southeast margin of the Bardain Jaran Desert,Northwest China,during the last glacial period.Four Qz-OSL ages are obtained,41.0±3.4 ka,54.7±4.4 ka,59.5±5.0 ka and 66.8±5.8 ka,corresponding to the depths of 35 cm,70 cm,150 cm and 200 cm respectively.Indicators like grain size,clay content,magnetic susceptibility,XRD and geochemical index(e.g.Sr,Ba,Sr/Ca)jointly indicate abrupt climate changes at the depth of 35 cm(age,ca.41.0 ka)and200 cm(age,ca.67 ka).Namely,the 280 cm sedimentary outcrop perfectly records a warm wet climate stage,corresponding to the late Marine Isotope Stages(MIS)4 to the early MIS 3.Besides,there is a trend of grain size increase after around 40ka BP,which is most likely a signal of wind strength change.Our research supports that enhancing Siberian High pressure system during the late MIS 3played a key role in NW East Asia climate evolution. 展开更多
关键词 last glacial period Bardain Jaran DESERT Climate change Siberian High pressure system XRD
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Provenance of Sediments Filling a Paleo-Channel that Formed on the Western Yellow Sea Continental Shelf During the Last Glacial Period 被引量:1
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作者 KONG Xianghuai ZHANG Junqiang +1 位作者 BAI Weiming LIU Jian 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第6期1309-1317,共9页
Several buried paleo-channels are located on the continental shelf of the western Yellow Sea. Research on the paleochannels is significant for both theoretical studies and practical applications. In this paper, we ana... Several buried paleo-channels are located on the continental shelf of the western Yellow Sea. Research on the paleochannels is significant for both theoretical studies and practical applications. In this paper, we analyse and discuss the mineralogy of sediments in a core(SYS-0803) recovered from a buried paleo-channel on the continental shelf of the western Yellow Sea. The aim is to determine the provenance of sediments that fill the paleo-channel. The heavy mineral assemblage of sediments in the core consists of schistose minerals, common hornblende, epidote, and ilmenite. The light mineral assemblage consists of plagioclase, quartz, lithic fragments, and K-feldspar. Analysis of the compositional maturity of the sand fraction revealed a quartz/feldspar ratio of < 1. A relatively high percentage of smectite is recorded throughout the entire paleo-channel fill, with the greatest percentage in the middle to lower parts. The detrital mineral assemblage and clay mineral content indicate that the paleo-channel sediments were sourced mainly from the Huanghe River during the last glacial period. 展开更多
关键词 continental shelf of the western Yellow Sea paleo-channel DETRITAL MINERAL clay MINERAL heavy MINERAL assemblage last glacial period sedimentary PROVENANCE
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Sedimentology and sequence stratigraphy of the mixed clastic-carbonate deposits in the Late Paleozoic icehouse period:A case study from the northern Qaidam Basin 被引量:1
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作者 Xiao-jie Wei Zong-xing Li +4 位作者 Yin-sheng Ma Yi-fan Li Jun-jie Hu Kui Liu Xin-xin Fang 《China Geology》 2021年第4期673-685,共13页
The widely-developed,mixed clastic-carbonate succession in the northern Qaidam Basin records the paleo-environment changes under the glacial activity during the Late Paleozoic icehouse period in the context of regiona... The widely-developed,mixed clastic-carbonate succession in the northern Qaidam Basin records the paleo-environment changes under the glacial activity during the Late Paleozoic icehouse period in the context of regional tectonic stability,however,the depositional environment and sequence stratigraphy characteristics of the mixed deposits is rarely reported and still not clear.Combined the latest drilling wells data,we analyzed the sedimentary and stratigraphic characterization of the mixed strata via detailed field outcrops and core observations and thin section microscopic observations and recognized three depositional systems,including progradational coastal system,incised valley system,and carbonate-dominated marine shelf system,and identified four third-order sequences,SQ1,SQ2,SQ3 and SQ4,consisting of LST,TST,and HST.The depositional environment is overall belonged to marine-continental transition context and shifted from marine to continental environment frequently,showing an evolutionary pattern from marine towards terrestrial-marine transition and then back into the marine environment again in the long-term,which was controlled by the regional tectonic subsidence and the high-frequency and large-amplitude sea-level changes due to the Late Paleozoic glacial activity.The result is of significance in understanding the evolution of the Qinghai-Tibet Plateau and the sedimentation-climate response. 展开更多
关键词 late Paleozoic icehouse period Mixed clastic-carbonate succession Marine-continental transition Sedimentation-climate response Geological survey engineering Qinghai-Tibetan Plateau
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Mechanism of the Effect of Bacillus coagulans on Production Performance of Laying Hens in Late Laying Period 被引量:2
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作者 Xing Guanrun Lang Xinrui +6 位作者 Wu Ji’an Lou Hongxing Liu Wenqiang Zhang Hengshuo Dong Xinyang Pan Xiaoliang Wang Youming 《Animal Husbandry and Feed Science》 CAS 2019年第5期125-130,共6页
[Objective]The paper was to investigate the mechanism of Bacillus coagulans preparation in improving production performance of laying hens in late period of laying.[Method]A total of 648 individuals of"Jingfen 1&... [Objective]The paper was to investigate the mechanism of Bacillus coagulans preparation in improving production performance of laying hens in late period of laying.[Method]A total of 648 individuals of"Jingfen 1"laying hens(66 weeks of age)in late period of laying were randomly divided into four groups,six replicates each group,and each group had 27 individuals of laying hens.The laying hens in control group were fed with basal diet,and those in experimental groupsⅠ,Ⅱ and Ⅲ were fed with the basal diets added with 3.33×10^6,1×10^7,3.33×10^7 CFU/g B.coagulans,respectively.The pretrial lasted one week,and the formal test lasted eight weeks.[Result]Compared with the control group,the laying rate in group Ⅰ increased significantly,and the feed-gain ratio in experimental group Ⅱ decreased noticeably while the spleen index increased remarkably;the alkaline phosphatase activities and blood calcium content in experimental groups Ⅰ,Ⅱ and Ⅲ increased significantly(P<0.05),while the triglyceride content decreased remarkably(P<0.05);the urea content in experimental groups Ⅰ and Ⅱ decreased obviously(P<0.05).Adding B.coagulans significantly increased the specific activity of amylase,lipase and protease in various intestinal mucosa of small intestine(P<0.05);adding B.coagulans significantly increased the content of follicle-stimulating hormone(FSH)and estradiol(E2),and significantly increased the mRNA expression of follicle stimulating hormone receptor gene(FSHR).[Conclusion]B.coagulans preparation could significantly improve the production performance of laying hens in late period of laying;appropriately enhance the immune capacity of laying hens;improve the serum biochemical indicators;increase the activity of digestive enzymes in the small intestine;and promote the release of gonadal hormone and the mRNA expression of FSHR gene in the ovary. 展开更多
关键词 Bacillus coagulans Laying hen late period of laying Production performance Serum biochemistry Small intestinal enzyme activity Reproductive hormones mRNA expression of ovary receptors
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North Atlantic Abrupt Climate Signals during the Last Glacial Period in Central Asia:Evidences from Aeolian Loess Sediments 被引量:1
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作者 SONG Yougui LI Yue +4 位作者 LI Yun AN Zhisheng CHENG Liangqing SUN Huanyu Rustam OROZBAEV 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第5期1942-1943,共2页
Objective Climate fluctuations over suborbital or millennial timescale display significant instability during the last glacial period,which are often superimposed upon the orbital periodicity.They triggered some abrup... Objective Climate fluctuations over suborbital or millennial timescale display significant instability during the last glacial period,which are often superimposed upon the orbital periodicity.They triggered some abrupt climate events, 展开更多
关键词 North Atlantic Abrupt Climate Signals during the last glacial period in Central Asia:Evidences from Aeolian Loess Sediments OSL
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Late Quaternary glacial-marine sedimentation in the Bransfield Strait off northeast Antarctic Peninsula 被引量:1
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作者 段威武 钟和贤 李扬 《Chinese Journal of Polar Science》 1996年第1期19-33,共15页
Systematical analyses of lithology,grain size, mineral composition,microbiological thanatocoenoses and other geological proxies from the sediments of piston core Pc10,drilled in the central part of the Bransfield Stra... Systematical analyses of lithology,grain size, mineral composition,microbiological thanatocoenoses and other geological proxies from the sediments of piston core Pc10,drilled in the central part of the Bransfield Strait, have been carried out. Based on the above data,together with the shipboard investigation, the 753 cm long core sediments reveal the last 112.5 ha deposits of the study area under the glacial-marine environment. The sediments includes biogenic silica deposit,volcanic debris deposit and turbidity current deposit.Among them,the biogenic silica deposit is dominative not only in the highstand water/interglacial stage, but also in the lowstand water/glacial stage.The difference of sedimentation between the two stages was that the terrigenous debris content and the sedimentation rate were lower in the lowstand water/glacial stage. 展开更多
关键词 Bransfield Strait late Pleistocene glacial-marine sedimentation
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Winter and summer monsoonal evolution in Gonghe Basin, northeastern Qinghai-Tibetan Plateau since the Last Glacial Maximum
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作者 Bing Liu HeLing Jin +2 位作者 Zhong Sun ZhiZhu Su CaiXia Zhang 《Research in Cold and Arid Regions》 CSCD 2013年第3期282-292,共11页
Geochemical and grain size analysis on the DQ (Dongqi) profile from Gonghe Basin, northeastern Qinghai-Tibetan Plateau, indi- cates that regional climate has experienced several cold-dry and warm-wet cycles since th... Geochemical and grain size analysis on the DQ (Dongqi) profile from Gonghe Basin, northeastern Qinghai-Tibetan Plateau, indi- cates that regional climate has experienced several cold-dry and warm-wet cycles since the last glacial maximum (LGM). The cold and dry climate dominated the region before 15.82 cal. ka B.E due to stronger winter monsoon and weaker summer monsoon, but the climate was relatively cold and wetter prior to 21 cal. ka B.E. In 15.824.5 cal. ka B.E, summer monsoon strength in- creased and winter monsoon tended to be weaker, implying an obvious warm climate. Specifically, the relatively cold and dry condition appeared in 14.7-13.7 cal. ka B.E and 12.14.5 cal. ka B.R, respectively, while relatively warm and wet in 13.~12.1 cal. ka B.E. The winter and summer monsoonal strength presents frequent fluctuations in the Holocene and relatively warm and wet conditions emerged in 9.5~.0 cal. ka B.E due to stronger summer monsoon. From 7.0 to 5.1 cal. ka B.E, the cycle of cold-dry and warm-wet climate corresponds to frequent fluctuations of winter and summer monsoons. The climate becomes warm and wet in 5.1 2.7 cal. ka B.E, accompanying increased summer monsoon, but it tends to be cold and dry since 2.7 cal. ka B.R due to en- hanced winter monsoonal strength. In addition, the evolution of regional winter and summer monsoons is coincident with warm and cold records from the polar ice core. In other words, climatic change in the Gonghe Basin can be considered as a regional re- sponse to global climate change. 展开更多
关键词 last glacial maximum period Gonghe Basin aeolian deposits winter and summer monsoonal evolution
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Upper Ocean Hydrology in the Indo-Pacific Warm Pool During the Late Holocene,Early Holocene and Last Glacial Maximum
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作者 Wolfgang Kuhnt Ann Holbourn Nils Andersen 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期224-224,共1页
We examined sediment samples from twenty-four stations in the Indo-Pacific warm pool(IPWP)region. Our objective is to provide a better understanding of changes in the IPWP and related tropical climatic phenomena such ... We examined sediment samples from twenty-four stations in the Indo-Pacific warm pool(IPWP)region. Our objective is to provide a better understanding of changes in the IPWP and related tropical climatic phenomena such as East Asian-Australian monsoon and El Ni(?)o-Southern Oscillation(ENSO),through improving spatial coverage of proxy records.In order 展开更多
关键词 PALEOCEANOGRAPHY upper ocean column INDO-PACIFIC WARM POOL late- and early-H-olocene last glacial maximum
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Palaeoclimatic Cycles, Global Environmental Changes and New Glacial Periods Induced by the Impact of Extraterrestrial Bodies
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作者 王世杰 欧阳自远 肖志峰 《Chinese Journal Of Geochemistry》 EI CAS 1999年第4期298-304,共7页
In terms of Earth\|Sun geometry, the Milankovitch theory has successfully explained most of the cyclic palaeoclimatic variations during the history of the Earth, especially in the Quaternary. In this paper, the author... In terms of Earth\|Sun geometry, the Milankovitch theory has successfully explained most of the cyclic palaeoclimatic variations during the history of the Earth, especially in the Quaternary. In this paper, the authors suggest that the impact of extraterrestrial bodies on the Earth may be another mechanism to cause palaeoclimatic cycles, global environmental changes and new glacial periods. Based on geological and geochemical records in the boundary layers produced by six huge Cenozoic bolide\|impact events (65, 34, 15, 2.4, 1.1, 0.73 Ma B.P.), including those at 34, 15, 1.1 and 0.73 Ma B.P. which are represented by four famous tektite\|strewn fields, the process and mechanics of palaeoclimatic cycles and global environmental catastrophes induced by extraterrestrial impact are discussed in detail. Impact\|generated dust, soot and aerosol floating in the stratosphere could result in short\|term (<1 year), rapid drop in temperature immediately after impact. Through self\|regulation of the Earth’s climate system, the temperature at the surface slowly went up within 100a and maintained stable for a long time at 250K. If there were no other factors leading to the break\|down of the newly\|established equilibrium, a new glacial period would be initiated. Estimating from the thickness of \{δ\{\}\+\{13\}C\} and \{δ\{\}\+\{18\}O\} anomalies in sediments across the impact boundary layer and deposition rate, the duration of two stages of the palaeoclimate cycle in the form of cold weather—greenhouse effect—normal weather was 10\+4-10\+5a, respectively. The conclusion deduced from the above model is supported by palaeotemperature change recorded by oxygen isotope in sediments across the impact boundary layer. 展开更多
关键词 古气候 地球环境 流星事件 新生代 新冰河时期
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A combination of castration with(125)~I brachtherapy in middle and late period prostate cancer
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作者 王海涛 《外科研究与新技术》 2011年第4期250-250,共1页
Objective To investigate the therapeutic efficacy of castration with 125 I brachtherapy in middle and late stage prostate cancer. Methods Sixty-six patients with prostate cancer from 2004 to 2009 were analyzed,40 were... Objective To investigate the therapeutic efficacy of castration with 125 I brachtherapy in middle and late stage prostate cancer. Methods Sixty-six patients with prostate cancer from 2004 to 2009 were analyzed,40 were at clinical stage C and 26 were at clinical stage D, 展开更多
关键词 A combination of castration with I brachtherapy in middle and late period prostate cancer
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Late Pleistocene glaciation of the Hulifang Massif of Gongwang mountains in Yunnan Province 被引量:13
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作者 ZHANG Wei CUI Zhijiu +2 位作者 FENG Jinliag YI Chaolu YA NG Jianqiang 《Journal of Geographical Sciences》 SCIE CSCD 2005年第4期448-458,共11页
Late Pleistocene glaciation was restricted to only a few high mountains in eastern China. The Gongwang mountains constitute one of the typical places once glaciated. Geomorphic mapping of the area and the TL dating pr... Late Pleistocene glaciation was restricted to only a few high mountains in eastern China. The Gongwang mountains constitute one of the typical places once glaciated. Geomorphic mapping of the area and the TL dating provides evidence for at least four distinct glaciations. YJT-Ⅰ glacial advance occurred about 100 ka BP and two TL absolute ages (101,100 ± 7780 a BP; 104,000± 8300 a BP) indicate this advance happened during the Penultimale Glaciation. The early stage glacial advance (YJT-Ⅱ advance) during the last glaciation occurred about 40,920 ± 3400 a BP. The last glacial maximum advance (YJT-Ⅲ advance) about 18-25 ka BP, which sustained by two TL ages (18,230 ±1420 a BP; 25,420 ± 2110 a BP). The Penultimale and the early stage glaciations were more extensive and the last glacial maximum (LGM) and the late-glacial period (YJT-Ⅳ advance, 10 ka BP) were progressively less extensive. Correlated with the other mountains in eastern China, these glacial advances in the Gongwang mountains just like the advances in the western part such as Diancang mountains, Yulong mountains of Yunnan Province and the glacier series are more complete than the adjacent mid-latitude regions such as Taibai mountain and Taiwan mountains and are roughly representative of climate changes during the last glacial cycle in Yunnan Province. 展开更多
关键词 glacial geomorphology TL dating late Pleistocene last glaciation China
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Geochronological and Geochemical Evidence for the Sedimentary Transformation from the Banxi Period to Nanhua Glacial Period 被引量:6
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作者 WANG Zhengjiang WANG Jian +3 位作者 DU Qiuding DENG Qi LIU Hao YANG Fei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第5期1915-1916,共2页
Objective There has been considerable debate about the definition of the lower boundary of Nanhua System by far.One definition is based on sedimentary sequence of different stages of basin evolution,focusing on whethe... Objective There has been considerable debate about the definition of the lower boundary of Nanhua System by far.One definition is based on sedimentary sequence of different stages of basin evolution,focusing on whether deposits of the Banxi Period should be classified as Nanhua System.Another is the onset time of Nanhua glacial period. 展开更多
关键词 Geochronological and Geochemical Evidence for the Sedimentary Transformation from the Banxi period to Nanhua glacial period PB
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The Glacial(MIS 3-2)Outlet Glacier of the Marsyandi Nadi-icestream-network with its Ngadi Khola Tributary Glacier(Manaslu-and Lamjung Himalaya):The Reconstructed Lowering of the Marsyandi Nadi Ice Stream Tongue down in to the Southern Himalaya Foreland 被引量:2
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作者 Matthias KUHLE 《Journal of Mountain Science》 SCIE CSCD 2014年第1期236-287,共52页
For the reconstruction of past climate variations,investigations on the history of glaciers are necessary.In the Himalaya,investigations like these have a rather short tradition in comparison with other mountains on e... For the reconstruction of past climate variations,investigations on the history of glaciers are necessary.In the Himalaya,investigations like these have a rather short tradition in comparison with other mountains on earth.At the same time,this area on the southern margin of Tibet is of special interest because of the question as to the monsoon-influence that is connected with the climate-development.Anyhow,the climate of High Asia is of global importance.Here for the further and regionally intensifying answer to this question,a glacial glacier reconstruction is submitted from the CentralHimalaya,more exactly from the Manaslu-massif.Going on down-valley from the glacial-historical investigations of 1977 in the upper Marsyandi Khola(Nadi) and the partly already published results of field campaigns in the middle Marsyandi Khola and the Damodar- and Manaslu Himal in the years 1995,2000,2004 and 2007,new geomorphological and geological field- and laboratory data are introduced here from the Ngadi(Nadi) Khola and the lower Marsyandi Nadi from the inflow of the Ngadi(Nadi) Khola down to the southern mountain foreland.There has existed a connected ice-stream-network drained down to the south by a 2,100-2,200 m thick and 120 km long Marsyandi Nadi main valley glacier.At a height of the valley bottom of c.1,000 m a.s.l.the Ngadi Khola glacier joined the still c.1,300 m thick Marsyandi parent glacier from the Himalchuli-massif(Nadi(Ngadi) Chuli) – the south spur of the Manaslu Himal.From here the united glacier tongue flowed down about a further 44 km to the south up to c.400 m a.s.l.(27°57'38 "N/84°24'56" E) into the Himalaya fore-chains and thus reached one of or the lowest past ice margin position of the Himalayas.The glacial(LGP(Last glacial period),LGM(Last glacial maximum) Würm,Stage 0,MIS 3-2) climatic snowline(ELA = equilibrium line altitude) has run at 3,900 to 4,000 m a.s.l.and thus c.1,500 altitude meters below the current ELA(Stage XII) at 5,400-5,500 m a.s.l.The reconstructed,maximum lowering of the climatic snowline(ΔELA = depression of the equilibrium line altitude) about 1,500 m corresponds at a gradient of 0.6°C per 100 altitude meters to a High Glacial decrease in temperature of 9°C(0.6 × 15 = 9).At that time the Tibetan inland ice has caused a stable cold high,so that no summer monsoon can have existed there.Accordingly,during the LGP the precipitation was reduced,so that the cooling must have come to more than only 9°C. 展开更多
关键词 Ice Age GLACIATION HIMALAYA Manaslu Ngadi Khola Icestream network last glacial period
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Social development and living environment changes in the Northeast Tibetan Plateau and contiguous regions during the late prehistoric period 被引量:5
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作者 Huihui Cao Guanghui Dong 《Regional Sustainability》 2020年第1期59-67,共9页
The relationship between the evolution of human societies and their living environments has been discussed intensively in recent decades.It is important to understand the patterns and mechanisms of human–environment ... The relationship between the evolution of human societies and their living environments has been discussed intensively in recent decades.It is important to understand the patterns and mechanisms of human–environment interaction and evolution in order to cope with rapidly changing environments in the modern world.We reviewed the results of dating,archaeobotanical,and zooarchaeological studies from 139 prehistoric sites in the Northeast Tibetan Plateau(NETP)and contiguous regions(NETP-CR:i.e.,the Hexi Corridor and western margin of the Chinese Loess Plateau)and compared them with paleoenvironmental records to study variations in spatiotemporal patterns of social development in the area and their relationships with climate and vegetation changes.Our results show that hunter-gatherer groups occupied vast areas of the NETP at low intensities during^15,000–5500 BP(years before present).This was directly related to forest cover and climate change.An increase in temperature and precipitation turnover of vegetation from desert steppe to alpine meadow/subalpine shrub,and recovery of animal population on the Tibetan Plateau created more food resources and space for hunter-gatherers.Millet farmers settled extensively below 2500 m a.s.l.(meters above sea level)in the NETP-CR between^5500 and 3600 BP,and might have coexisted with hunting groups above 2500 m a.s.l.via subsistence exchange.The distribution of human settlements during that period was affected by climate change,with the relatively warm and wet climate promoting the expansion of millet agriculture to the NETP-CR during 5500–4500 BP,while climate deterioration caused humans to retreat to lower altitudes.During 3600–2200 BP,a range of livelihoods emerged in different regions of the NETPCR.This was promoted by early trans-Eurasian exchange and the development of an agro-pastoral economy that utilized cold-tolerant crops and livestock.This eventually promoted the expansion of permanent human settlements to high-altitude areas in the NETP.This study found that human societies adopted various strategies to adapt to the changing living environment throughout late prehistoric times in the NETP-CR.The results provide a long-term perspective on the trajectory of regional socio-environmental co-evolution. 展开更多
关键词 Social evolution Climate change Subsistence strategy late prehistoric period Northeast Tibetan Plateau
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Heavy mineral stratigraphy of sediments from the southern outer shelf of the East China Sea since the last glaciation using fuzzy C-means cluster method 被引量:1
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作者 林晓彤 李巍然 +1 位作者 杜树杰 林振宏 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第1期183-189,共7页
Correspondence analysis and fuzzy C-means cluster methods were used to divide the stratigraphy of heavy mineral assemblages,and the sediment sources and depositional dynamics of the environment reconstructed.The assem... Correspondence analysis and fuzzy C-means cluster methods were used to divide the stratigraphy of heavy mineral assemblages,and the sediment sources and depositional dynamics of the environment reconstructed.The assemblages were taken from marine sediments from the late Pleistocene to the Holocene in Core Q43 situated on the outer shelf of the East China Sea.Based on the variable boundaries of the mineral assemblage at 63 and 228 cmbsf (cm below sea floor),the core might have previously been divided into three sediment strata marked with units I,II and III,which would be consistent with the divided sediment stratum of the core using minor element geochemistry.The downcore distribution of heavy minerals divided the sedimentary sequence into three major units,which were further subdivided into four subunits.The interval between 0 and 63 cmbsf of the core (unit I),which spans the Holocene and the uppermost late Pleistocene,is characterized by a hornblende-epidote-pyroxene assemblage,and contains relatively a smaller amount of schistic mineral and authigenic pyrite.In comparison,the interval between 63 and 228 cmbsf (unit II),is representative of the Last Glacial Maximum (LGM),and features a hornblende-epidote-magnetite-ilmenite assemblage containing the highest concentrations of heavy minerals and opaque minerals.However,the interval between 228 and 309 cmbsf (unit III),which spans the subinterglacial period,is characterized by a hornblende-authigenic-pyrite-mica assemblage.Relative ratios of some heavy minerals can be used as tracers of clastic sediment sources.The lower part of the sediment core shows the highest magnetite/ilmenite ratio and relatively high hornblende/augite and hornblende/epidote ratios.The middle core shows the highest hornblende/augite and hornblende/epidote ratios,and the lowest magnetite/ilmenite ratio.The upper part exhibits a slightly higher magnetite/ilmenite ratio,and also the lowest hornblende/augite and hornblende/epidote ratios.The distribution of the mineral ratio is consistent with stratigraphic division in heavy mineral data using correspondence analysis and fuzzy C-means clustering.Variations in heavy mineral association and mineral ratio in core Q43 revealed changes in provenance and depositional environment of the southern outer shelf of the East China Sea since the late Pleistocene,well corresponding to interglacial and glacial cycles. 展开更多
关键词 重矿物组合 海洋沉积物 末次盛冰期 沉积地层 中国陆架 均值聚类 聚类法 模糊
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Social Classes and Cultural Connotations of Yangzhou Home Gardens during the Late Qing Dynasty and the Republic of China
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作者 ZHANG Lihui 《Journal of Landscape Research》 2016年第6期102-106,共5页
During the late Qing Dynasty and the early period of the Republic of China(1870-1930),the social classes in Yangzhou were basically dominated by officials,businessmen,and scholars.In the building number,scale,and func... During the late Qing Dynasty and the early period of the Republic of China(1870-1930),the social classes in Yangzhou were basically dominated by officials,businessmen,and scholars.In the building number,scale,and functional evolution of their home gardens,these three classes were different,reflecting abundant connotation of characteristic of the time and regional culture,revealing the inheritance path of Yangzhou culture,as well as the richness and diversity of home gardens in Yangzhou during the late Qing Dynasty and the early period of the Republic of China. 展开更多
关键词 Social classes the late Qing Dynasty and the early period of the Republic of China Yangzhou home gardens Type characteristics Cultural connotation
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A Late Quaternary Climate Record Based on Multi-Proxies Analysis from the Jiaochang Loess Section in the Eastern Tibetan Plateau,China 被引量:5
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作者 BAI Song TANG Ya +1 位作者 WANG Chengshan HUANG Chengmin 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2007年第6期1087-1096,共10页
We compared the stable carbon isotopic records from a loess transect of the Jiaochang in the eastern Tibetan Plateau, spanning the last -21,000 years, with multiproxy data for pedogenesis, including magnetic susceptib... We compared the stable carbon isotopic records from a loess transect of the Jiaochang in the eastern Tibetan Plateau, spanning the last -21,000 years, with multiproxy data for pedogenesis, including magnetic susceptibility, clay fraction, Fed/Fet ratio, carbonate and total organic carbon content, in order to probe the mechanisms of δ^13C values of organic matter and Late Quaternary climate variations in the eastern Tibetan Plateau. Our results indicate that there is no simple relationship between δ^13C of organic matter and summer monsoon variations. The change in δ^13C values of organic matter (in accordance with the ratios of C3 to C4 plants) results from the interaction among temperature, aridity and atmospheric pCO2 level. Drier climate and lower atmospheric pCO2 level contribute to positive carbon isotopic excursion, while negative carbon isotopic excursion is the result of lower temperature and increased atmospheric pCO2 level. Additionally, our results imply that the Tibetan monsoon may play an important role in climate system in the eastern Tibet Plateau, which specifically reflects frequently changing climate in that area. The results provide new insights into the forcing mechanisms on both the δ^13C values of organic matter and the local climate system. 展开更多
关键词 eastern Tibetan Plateau Jiaochang loess carbon isotope last glacial late Quaternary
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Metallogenic Mechanism and Tectonic Setting of Tungsten Mineralization in the Yangbishan Deposit in Northeastern China 被引量:4
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作者 HAO Yujie REN Yunsheng +3 位作者 ZHAO Hualei LAI Ke ZHAO Xuan MA Yupeng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2018年第1期241-267,共27页
The Yangbishan iron-tungsten deposit in the Shuangyashan area of Heilongjiang Province is located in the center of the Jiamusi Massif in northeastern China. The rare earth element and trace element compositions of the... The Yangbishan iron-tungsten deposit in the Shuangyashan area of Heilongjiang Province is located in the center of the Jiamusi Massif in northeastern China. The rare earth element and trace element compositions of the scheelite show that it formed in a reducing environment and inherited the rare earth element features of the ore-forming fluid. The geochemical characteristics of the gneissic granite associated with the tungsten mineralization show that the magma formed in this reducing environment and originated from the partial melting of metamorphosed shale that contained organic carbon and was enriched with tungsten. In addition, in situ Hf isotopic analysis of zircons from the gneissic granite indicates that they probably originated from the partial melting of a predominantly Paleo-Mesoproterozoic crustal source. According to LA-ICP-MS zircon dating, the Yangbishan ore- related gneissic granite has an Early Paleozoic crystallization age of 520.6 + 2.8 Ma. This study, together with previous data, indicates that the massifs of northeastern China, including Erguna, Xing'an, Songliao, Jiamusi, and Khanka massifs, belonged to an orogenic belt that existed along the southern margin of the Siberian Craton during the late Pan-African period. The significant continental movements of this orogeny resulted in widespread magmatic activity in northeastern China from 530 Ma to 470 Ma under a tectonic setting that transitioned from compressional syn-collision to extensional post- collision. 展开更多
关键词 SCHEELITE Yangbishan iron-tungsten deposit Early Paleozoic late Pan-African period Central Asian Orogenic Belt
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Late Quaternary Paleoclimatic Change in the Ulleung Basin,East Sea,Korea 被引量:1
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作者 Young-Suk BAK Young-Up LEE 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第1期263-269,共7页
Paleoclimatic changes in the late Quaternary sediments deposited in the East Sea were analyzed by studying diatoms. A total of 95 species belonging to 47 genera were identified from the Core02GHP-02 of the Ulleung Bas... Paleoclimatic changes in the late Quaternary sediments deposited in the East Sea were analyzed by studying diatoms. A total of 95 species belonging to 47 genera were identified from the Core02GHP-02 of the Ulleung Basin in the East Sea, Korea. In the Core 02GHP-02, U-Oki(169–181 cm; 9.3 ka), AT(464–465.5 cm; 22 ka) and U–Ym(556–559 cm; 33 ka) tephra layers were recognized. The chronological divisions of 02GHP-02 may be correlated with the climatic changes from the glacial interval(730–620 cm; MIS3), to interstadial(620–500 cm; MIS3), to the last glacial maximum(500–390 cm; MIS 2), to the deglaciation(390–290 cm; MIS 2), to the late glacial(290–190 cm; MIS 1), and to the Holocene(190–10 cm; MIS 1). It is speculated that diatoms were rarely found during the glacial interval when the 02GHP-02 core was deposited; during the interstadial(MIS 3) and deglaciation, a mixture of warm-water and cold-water species were found. In particular, Fragilariopsis doliolus seems to have appeared in the East Sea after 8 ka BP. In the lower layers of the Holocene deposits, cold-water species such as Neodenticula seminae were frequently found, while in the upper layers, warm-water species such as Hemidiscus cuneiformis were found in relatively large abundance. Therefore, the findings indicate that the climate became warmer during the transition from the lower layer to the upper layer of the Holocene deposits. 展开更多
关键词 DIATOMS paleoclimatic change late Quaternary glacial interval MIS
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The Pleistocene Glaciation in the Karakoram Mountains:Reconstruction of Past Glacier Extensions and Ice Thicknesses 被引量:2
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作者 Matthias Kuhle 《Journal of Mountain Science》 SCIE CSCD 2004年第1期3-17,共15页
关键词 更新世 冰河作用 古气候 冰河地形学
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