The term "westerlies-dominated climatic regime" describes the pattern of precipitation/moisture variations between westerliesdominated arid Central Asia(ACA) and mid-latitude monsoon-dominated Asia on decada...The term "westerlies-dominated climatic regime" describes the pattern of precipitation/moisture variations between westerliesdominated arid Central Asia(ACA) and mid-latitude monsoon-dominated Asia on decadal to multi-millennial time scales. However, no attempts have been made to define its core region and the possible physical mechanisms responsible during the period of instrumental observations. The present study investigates the spatiotemporal variations of summer and winter precipitation on interannual to decadal time scales over mid-latitudes of the Eurasian continent using Empirical Orthogonal Function(EOF) analysis. Our results suggest the existence of an opposing pattern of summer precipitation variations between ACA and mid-latitude monsoon-dominated Asia and Mediterranean on decadal time scales. Based on these results, the core region influenced by the westerlies is outlined, including arid central Asia and Xinjiang in China(36°–54°N, 50°–90°E). By using monthly NCEP-NCAR reanalysis, the relationship between the "westerlies-dominated climatic regime" and atmospheric circulation were also analyzed. The combination of the zonal climatic teleconnection pattern and anomalous Indian Summer Monsoon Precipitation(ISMP) causes the precipitation characteristics of the "westerlies-dominated climatic regime" precipitation pattern. In addition, the Atlantic Multidecadal Oscillation(AMO) may also have an important effect on the "westerlies-dominated climatic regime".展开更多
Three sediment cores were collected in November 2003 from Dagu estuary to Qikou estuary. The main polluted heavy metals in the sediment of tidal zones for the Bohai Bay have been found by analyzing the relationship am...Three sediment cores were collected in November 2003 from Dagu estuary to Qikou estuary. The main polluted heavy metals in the sediment of tidal zones for the Bohai Bay have been found by analyzing the relationship among the contents of heavy metals, the contents of geochemical elements （Fe, AI and Mn） and the size of grain. The dominating contaminative elements in tidal sediments of Bohai Bay are Pb, Zn and Cd. Their contents are higher than the corresponding upper limit of environmental background values and they have very faint correlation with the corresponding contents of geochemical elements and the size of grain, indicating the anthropogenic enrichment. Especially, the preliminary study on the pollution sources and the history of heavy metals in the Dagu estuary has been done using the dated results. The contamination by Zn and Cd also started in the middle 1950s, while the contamination by Pb appeared in the early 1940s. The pollution by Zn and Cd mainly originate from sewage discharge, while the pollution by Pb has many sources, like atmosphere deposition and industrial discharRe.展开更多
A series of ductile shear zones of the overthrust and strike-slip-types and related ductile shear metamorphicrocks, including tectonic melange and mylonites. were formed in the core of the Qinling orogenic belt in the...A series of ductile shear zones of the overthrust and strike-slip-types and related ductile shear metamorphicrocks, including tectonic melange and mylonites. were formed in the core of the Qinling orogenic belt in thecourse of the Caledonian-Indosinian ductilc and brittle-ductile reworking. The study on their petrography. va-riations in composition and conditions of formation is conducive to revealing the metamorphism-deformationhistory of the core of the Qinling orogenic belt and further to understanding the dynamic mechanism of its evo-lution.展开更多
基金supported by National Basic Research Program of China(Grant No.2010CB950202)National Natural Science Foundation of China(Grant No.41130102)+2 种基金Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20120211130001)Fundamental Research Funds for the Central Universities(Grant No.LZUJBKY-2014-119)the Open Foundation of MOE Key Laboratory of Western China’s Environmental System,Lanzhou University(Grant No.LZUJBKY-2013-BT01)
文摘The term "westerlies-dominated climatic regime" describes the pattern of precipitation/moisture variations between westerliesdominated arid Central Asia(ACA) and mid-latitude monsoon-dominated Asia on decadal to multi-millennial time scales. However, no attempts have been made to define its core region and the possible physical mechanisms responsible during the period of instrumental observations. The present study investigates the spatiotemporal variations of summer and winter precipitation on interannual to decadal time scales over mid-latitudes of the Eurasian continent using Empirical Orthogonal Function(EOF) analysis. Our results suggest the existence of an opposing pattern of summer precipitation variations between ACA and mid-latitude monsoon-dominated Asia and Mediterranean on decadal time scales. Based on these results, the core region influenced by the westerlies is outlined, including arid central Asia and Xinjiang in China(36°–54°N, 50°–90°E). By using monthly NCEP-NCAR reanalysis, the relationship between the "westerlies-dominated climatic regime" and atmospheric circulation were also analyzed. The combination of the zonal climatic teleconnection pattern and anomalous Indian Summer Monsoon Precipitation(ISMP) causes the precipitation characteristics of the "westerlies-dominated climatic regime" precipitation pattern. In addition, the Atlantic Multidecadal Oscillation(AMO) may also have an important effect on the "westerlies-dominated climatic regime".
基金The National Basic Research Program (973) of China (No. 2002CB412409) and the Hi-Tech Research and Development Program(863) of China(No. 2002AA648010)
文摘Three sediment cores were collected in November 2003 from Dagu estuary to Qikou estuary. The main polluted heavy metals in the sediment of tidal zones for the Bohai Bay have been found by analyzing the relationship among the contents of heavy metals, the contents of geochemical elements （Fe, AI and Mn） and the size of grain. The dominating contaminative elements in tidal sediments of Bohai Bay are Pb, Zn and Cd. Their contents are higher than the corresponding upper limit of environmental background values and they have very faint correlation with the corresponding contents of geochemical elements and the size of grain, indicating the anthropogenic enrichment. Especially, the preliminary study on the pollution sources and the history of heavy metals in the Dagu estuary has been done using the dated results. The contamination by Zn and Cd also started in the middle 1950s, while the contamination by Pb appeared in the early 1940s. The pollution by Zn and Cd mainly originate from sewage discharge, while the pollution by Pb has many sources, like atmosphere deposition and industrial discharRe.
文摘A series of ductile shear zones of the overthrust and strike-slip-types and related ductile shear metamorphicrocks, including tectonic melange and mylonites. were formed in the core of the Qinling orogenic belt in thecourse of the Caledonian-Indosinian ductilc and brittle-ductile reworking. The study on their petrography. va-riations in composition and conditions of formation is conducive to revealing the metamorphism-deformationhistory of the core of the Qinling orogenic belt and further to understanding the dynamic mechanism of its evo-lution.
