Given the conflicts over the proposed formation mechanisms of Xiashu loess, the question of the provenance of sediments comprising the Xiashu loess in the Yangtze River Delta has not been satisfactorily resolved. In t...Given the conflicts over the proposed formation mechanisms of Xiashu loess, the question of the provenance of sediments comprising the Xiashu loess in the Yangtze River Delta has not been satisfactorily resolved. In this study, the provenance of aeolian sediments of the Yangtze River Delta, China was examined by applying the detrial zircon U–Pb dating technique, Sr–Nd isotopic and trace element compositional analysis. U-Pb dating analysis was conducted on the Xiashu loess at three locations over the Yangtze River Delta, including Huangnishan(HNS) hill, Shengshan(SS) island and the Xuancheng(XC) area. The Xiashu loess and the sediments of the Yangtze River Valley share considerable similarity in their zircon U-Pb age spectra with the same main age peak and comparable age distribution. By contrast, significant differences in the age spectra, existbetween the Xiashu loess and loess deposits of Chinese Loess Plateau(CLP). Coarse grains of the Yangtze River Delta loess may have a proximal material source identical to the sediments from the Yangtze River valley. Sr–Nd isotopic values of the Xiashu loess match those from the northern margin of the Tibetan Plateau. Rare earth element ratios independent of grain size illustrate that the values from loess of the Yangtze River Delta mostly overlap with those of CLP loess. This feature implies that loess from the Yangtze River Delta has a dominant source of distant material similar as the CLP loess. As such, we conclude that multi-proxy analysis of sediments can shed new light on tracing the provenance of aeolian loess in the Yangtze River Delta.展开更多
In this paper, we reconsider the defining but often overlooked ‘hinge' function of megalopolises by analyzing how megalopolises have articulated national and international urban systems in the context of a global...In this paper, we reconsider the defining but often overlooked ‘hinge' function of megalopolises by analyzing how megalopolises have articulated national and international urban systems in the context of a globalizing knowledge economy. Taking the case of China's Yangtze River Delta(YRD) region, we particularly focus on knowledge circulation within and beyond the YRD region by analyzing the pattern and process of knowledge collaboration at different geographical scales during the 2004–2014 period. Results show that the structure of scientific knowledge collaboration as reflected by co-publications has been strongest at the national scale whereas that of technological knowledge collaboration as measured by co-patents has been strongest at the global scale. Despite this difference, the structure of both scientific and technological knowledge collaboration has been functionally polycentric at the megalopolitan scale but become less so at the national and global scales. The ‘globally connected but locally disconnected' pattern of Shanghai's external knowledge collaboration suggests that the gateway role of the YRD megalopolis in promoting knowledge collaboration at different geographical scales will take time before it is fully realized.展开更多
Based on a synthetic geological study of drilling, well logging and core observations, two main genetic types of Chang 9sand body in Odors Basin were recognized, which included two effects, that is, delta environment ...Based on a synthetic geological study of drilling, well logging and core observations, two main genetic types of Chang 9sand body in Odors Basin were recognized, which included two effects, that is, delta environment and tractive current effects that lead to the development of mouth bar, distal bar, sheet sand and other sand bodies of subaerial and subaqueous distributary channel,natural levee, flood fan and delta front, and shore-shallow lake environment and lake flow transformation effects that result in the development of sandy beach bar, sheet sand and other sand bodies. Chang 9 sand body mainly developed five basic vertical structures, namely box shape, campaniform, infundibuliform, finger and dentoid. The vertical stacking patterns of multilayer sand body was complex, and the common shapes included box shape + box shape, campaniform + campaniform, campaniform + box shape, infundibuliform + infundibuliform, campaniform + infundibuliform, box shape + campaniform, box shape + infundibuliform,and finger + finger. Based on the analysis on major dominating factors of vertical structure of sand body, sedimentary environment,sedimentary facies and rise, fall and cycle of base level are identified as the major geological factors that control the vertical structure of single sand body as well as vertical stacking patterns and distribution of multistory sand bodies.展开更多
SO2 is an important gas in atmosphere with great environmental and climate implications.SO2 emission in China has been receiving great attention as the economy grows and the amount of coal consumption has increased in...SO2 is an important gas in atmosphere with great environmental and climate implications.SO2 emission in China has been receiving great attention as the economy grows and the amount of coal consumption has increased in the past few decades.SO2 has been observed from July 2005 to June 2010 at Linan WMO GAW regional station(30.3 °N,119.73 °E,138 m a.s.l.) located in the Yangtze Delta region in eastern China.These observation data are analyzed to understand the trend of regional SO2 background concentration.Strict quality controls are conducted to ensure the temporal comparability of the data.Significant downward trend with ?2.4 ppb/yr(P < 0.0001) of surface SO2 is observed from 2005 to 2010,especially after 2008.The average concentration of SO2 from July 2005 to June 2008 is 14.2±3.1 ppb,which is slightly higher than the mean values of 13.5±5.1 ppb during 1999?2000 and is two folds of the average value(7.1±3.1 ppb) from July 2008 to June 2010.More than 50% of the SO2 has been cut down after 2008 in the Yangtze Delta region due to the implementation of stricter emission control measures.The peak SO2 concentration appears around 10 o'clock in the morning after 2009 while appears at night before 2009.These diurnal variations of SO2 might indicate that after 2009,more SO2 is from the vertical exchange process than from the local accumulation.展开更多
In the past nearly 30 years, the emergence of the market economies in China was characterised by geographical concentration of economic activities. The particularly successful cases happened in the Yangtze River Delta...In the past nearly 30 years, the emergence of the market economies in China was characterised by geographical concentration of economic activities. The particularly successful cases happened in the Yangtze River Delta, namely, the two most famous models for local developments in China＇s economic transformation and market development： the ＂ South Jiangsu Model＂ in south Jiangsu and the ＂Wenzhou model＂ in southeast Zhejiang. Although there have been debates upon the two development models for a considerably long time, both models keep being open in and compatible to local development and globalization. The two models influence each other, keep being in institutional transition through bilateral paths transplantation, i.e. learning from each other and employing cooperation in their developments. Transition and transplantation are adaptation mechanisms for local developments of the two models to participate in global economies with industrial division and labour division, and also for the two models to continuously further contribute to China＇s nationwide market transition and economic development.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 41371032, 41671003, 41601189, 41672349)
文摘Given the conflicts over the proposed formation mechanisms of Xiashu loess, the question of the provenance of sediments comprising the Xiashu loess in the Yangtze River Delta has not been satisfactorily resolved. In this study, the provenance of aeolian sediments of the Yangtze River Delta, China was examined by applying the detrial zircon U–Pb dating technique, Sr–Nd isotopic and trace element compositional analysis. U-Pb dating analysis was conducted on the Xiashu loess at three locations over the Yangtze River Delta, including Huangnishan(HNS) hill, Shengshan(SS) island and the Xuancheng(XC) area. The Xiashu loess and the sediments of the Yangtze River Valley share considerable similarity in their zircon U-Pb age spectra with the same main age peak and comparable age distribution. By contrast, significant differences in the age spectra, existbetween the Xiashu loess and loess deposits of Chinese Loess Plateau(CLP). Coarse grains of the Yangtze River Delta loess may have a proximal material source identical to the sediments from the Yangtze River valley. Sr–Nd isotopic values of the Xiashu loess match those from the northern margin of the Tibetan Plateau. Rare earth element ratios independent of grain size illustrate that the values from loess of the Yangtze River Delta mostly overlap with those of CLP loess. This feature implies that loess from the Yangtze River Delta has a dominant source of distant material similar as the CLP loess. As such, we conclude that multi-proxy analysis of sediments can shed new light on tracing the provenance of aeolian loess in the Yangtze River Delta.
文摘In this paper, we reconsider the defining but often overlooked ‘hinge' function of megalopolises by analyzing how megalopolises have articulated national and international urban systems in the context of a globalizing knowledge economy. Taking the case of China's Yangtze River Delta(YRD) region, we particularly focus on knowledge circulation within and beyond the YRD region by analyzing the pattern and process of knowledge collaboration at different geographical scales during the 2004–2014 period. Results show that the structure of scientific knowledge collaboration as reflected by co-publications has been strongest at the national scale whereas that of technological knowledge collaboration as measured by co-patents has been strongest at the global scale. Despite this difference, the structure of both scientific and technological knowledge collaboration has been functionally polycentric at the megalopolitan scale but become less so at the national and global scales. The ‘globally connected but locally disconnected' pattern of Shanghai's external knowledge collaboration suggests that the gateway role of the YRD megalopolis in promoting knowledge collaboration at different geographical scales will take time before it is fully realized.
基金Project(2011D-5006-0105)supported by the Technology Innovation Foundation of CNPC,ChinaProject(SZD0414)supported by the Key Discipline of Mineral Prospecting and Exploration of Sichuan Province,China
文摘Based on a synthetic geological study of drilling, well logging and core observations, two main genetic types of Chang 9sand body in Odors Basin were recognized, which included two effects, that is, delta environment and tractive current effects that lead to the development of mouth bar, distal bar, sheet sand and other sand bodies of subaerial and subaqueous distributary channel,natural levee, flood fan and delta front, and shore-shallow lake environment and lake flow transformation effects that result in the development of sandy beach bar, sheet sand and other sand bodies. Chang 9 sand body mainly developed five basic vertical structures, namely box shape, campaniform, infundibuliform, finger and dentoid. The vertical stacking patterns of multilayer sand body was complex, and the common shapes included box shape + box shape, campaniform + campaniform, campaniform + box shape, infundibuliform + infundibuliform, campaniform + infundibuliform, box shape + campaniform, box shape + infundibuliform,and finger + finger. Based on the analysis on major dominating factors of vertical structure of sand body, sedimentary environment,sedimentary facies and rise, fall and cycle of base level are identified as the major geological factors that control the vertical structure of single sand body as well as vertical stacking patterns and distribution of multistory sand bodies.
基金supported by the Planning Project Fund of Humanities and Social Science,Ministry of Education,China (11YJAZH071)the Basic Research Fund of CAMS (2011Z003)+1 种基金CMA (GYHY200706036)Desert Meteorological Foundation of CMA (Sqj2010012)
文摘SO2 is an important gas in atmosphere with great environmental and climate implications.SO2 emission in China has been receiving great attention as the economy grows and the amount of coal consumption has increased in the past few decades.SO2 has been observed from July 2005 to June 2010 at Linan WMO GAW regional station(30.3 °N,119.73 °E,138 m a.s.l.) located in the Yangtze Delta region in eastern China.These observation data are analyzed to understand the trend of regional SO2 background concentration.Strict quality controls are conducted to ensure the temporal comparability of the data.Significant downward trend with ?2.4 ppb/yr(P < 0.0001) of surface SO2 is observed from 2005 to 2010,especially after 2008.The average concentration of SO2 from July 2005 to June 2008 is 14.2±3.1 ppb,which is slightly higher than the mean values of 13.5±5.1 ppb during 1999?2000 and is two folds of the average value(7.1±3.1 ppb) from July 2008 to June 2010.More than 50% of the SO2 has been cut down after 2008 in the Yangtze Delta region due to the implementation of stricter emission control measures.The peak SO2 concentration appears around 10 o'clock in the morning after 2009 while appears at night before 2009.These diurnal variations of SO2 might indicate that after 2009,more SO2 is from the vertical exchange process than from the local accumulation.
文摘In the past nearly 30 years, the emergence of the market economies in China was characterised by geographical concentration of economic activities. The particularly successful cases happened in the Yangtze River Delta, namely, the two most famous models for local developments in China＇s economic transformation and market development： the ＂ South Jiangsu Model＂ in south Jiangsu and the ＂Wenzhou model＂ in southeast Zhejiang. Although there have been debates upon the two development models for a considerably long time, both models keep being open in and compatible to local development and globalization. The two models influence each other, keep being in institutional transition through bilateral paths transplantation, i.e. learning from each other and employing cooperation in their developments. Transition and transplantation are adaptation mechanisms for local developments of the two models to participate in global economies with industrial division and labour division, and also for the two models to continuously further contribute to China＇s nationwide market transition and economic development.
