Daily precipitation series at 15 stations in the Beijing metropolitan region（BMR） during 1960–2012 were homogenized using the multiple analysis of series for homogenization method,with additional adjustments based ...Daily precipitation series at 15 stations in the Beijing metropolitan region（BMR） during 1960–2012 were homogenized using the multiple analysis of series for homogenization method,with additional adjustments based on analysis of empirical cumulative density function（ECDF） regarding climate extremes.The cumulative density functions of daily precipitation series,the trends of annual and seasonal precipitation,and summer extreme events during 1960–2012 in the original and final adjusted series at Beijing station were comparatively analyzed to show the necessity and efficiency of the new method.Results indicate that the ECDF adjustments can improve the homogeneity of high-order moments of daily series and the estimation of climate trends in extremes.The linear trends of the regional-mean annual and seasonal（spring,summer,autumn,and winter）precipitation series are-10.16,4.97,-20.04,5.02,and-0.11 mm（10 yr）-1,respectively.The trends over the BMR increase consistently for spring/autumn and decrease for the whole year/summer; however,the trends for winter decrease in southern parts and increase in northern parts.Urbanization affects local trends of precipitation amount,frequency,and intensity and their geographical patterns.For the urban-influenced sites,urbanization tends to slow down the magnitude of decrease in the precipitation and extreme amount series by approximately-10.4% and-6.0%,respectively; enhance the magnitude of decrease in precipitation frequency series by approximately 5.7%; reduce that of extremes by approximately-8.9%; and promote the decreasing trends in the summer intensity series of both precipitation and extremes by approximately 6.8% and51.5%,respectively.展开更多
Surface pressure_area isotherms of two C 60derivatives, ethoxycarbonyldecylene_fullerene and bis(ethoxycarbonyldecylene)fullerene, have been investigated. The molecular aggregation at the air_water interface was reduc...Surface pressure_area isotherms of two C 60derivatives, ethoxycarbonyldecylene_fullerene and bis(ethoxycarbonyldecylene)fullerene, have been investigated. The molecular aggregation at the air_water interface was reduced and the transfer behavior to various substrates was enhanced as compared with those of pure C 60. Structural characterization of the LB films was carried out using high resolution transmission electron microscopy (HRTEM). The HRTEM images revealed regular stacking of the densest packed rows of molecules in the LB films.展开更多
基金supported by the State Programs of Science and Technology Development(Grant No.2012BAC22B04)the National Natural Science Foundation of China(Grant No.41475078)+1 种基金the National Department Public Benefit Research Foundation of China(Grant No.GYHY201206013)the Science and Technology program of the Institute of Urban Meteorology(Grant No.IUMKY201302PP0102)
文摘Daily precipitation series at 15 stations in the Beijing metropolitan region（BMR） during 1960–2012 were homogenized using the multiple analysis of series for homogenization method,with additional adjustments based on analysis of empirical cumulative density function（ECDF） regarding climate extremes.The cumulative density functions of daily precipitation series,the trends of annual and seasonal precipitation,and summer extreme events during 1960–2012 in the original and final adjusted series at Beijing station were comparatively analyzed to show the necessity and efficiency of the new method.Results indicate that the ECDF adjustments can improve the homogeneity of high-order moments of daily series and the estimation of climate trends in extremes.The linear trends of the regional-mean annual and seasonal（spring,summer,autumn,and winter）precipitation series are-10.16,4.97,-20.04,5.02,and-0.11 mm（10 yr）-1,respectively.The trends over the BMR increase consistently for spring/autumn and decrease for the whole year/summer; however,the trends for winter decrease in southern parts and increase in northern parts.Urbanization affects local trends of precipitation amount,frequency,and intensity and their geographical patterns.For the urban-influenced sites,urbanization tends to slow down the magnitude of decrease in the precipitation and extreme amount series by approximately-10.4% and-6.0%,respectively; enhance the magnitude of decrease in precipitation frequency series by approximately 5.7%; reduce that of extremes by approximately-8.9%; and promote the decreasing trends in the summer intensity series of both precipitation and extremes by approximately 6.8% and51.5%,respectively.
文摘Surface pressure_area isotherms of two C 60derivatives, ethoxycarbonyldecylene_fullerene and bis(ethoxycarbonyldecylene)fullerene, have been investigated. The molecular aggregation at the air_water interface was reduced and the transfer behavior to various substrates was enhanced as compared with those of pure C 60. Structural characterization of the LB films was carried out using high resolution transmission electron microscopy (HRTEM). The HRTEM images revealed regular stacking of the densest packed rows of molecules in the LB films.
