Climate effect caused by urbanization has been an indispensable anthropogenic factor in the research on regional climate change.Based on daily precipitation data,possible effects of precipitation on the development of...Climate effect caused by urbanization has been an indispensable anthropogenic factor in the research on regional climate change.Based on daily precipitation data,possible effects of precipitation on the development of three city groups in eastern China are discussed.With three classification methods(TP,PD and MODIS land cover),urban and rural stations are identified.The main findings are as follows.Climate effects caused by urbanization are different from place to place.In 1960 to 2009,the urbanization brought more precipitation to the Yangtze River Delta and Pearl River Delta city groups but had no obvious effect on the precipitation of the Beijing-Tianjin-Tangshan city group.The difference of precipitation is slight between urban and suburban areas during slow period of the urbanization from 1960 to 1979.It is more evident in the rapid period(1980 to 2009) that urbanization has positive effects on precipitation in every city group.The difference of precipitation between urban and rural stations is sensitive to the ways of distinguishing rural from urban area,which may cause uncertainties in 1960 to 1979,while it is very different in 1980 to 2009 in which urbanization favors more precipitation in all city groups and their differences in precipitation are not sensitive to the division methods.展开更多
To evaluate the contaminated conditions of benzo[alpyrene （B[a]P） and phenanthrene （PA） in sludge and to ascertain whether B[a]P limit for land application of sludge exists, the contents of B[a]P and PA in 46 slud...To evaluate the contaminated conditions of benzo[alpyrene （B[a]P） and phenanthrene （PA） in sludge and to ascertain whether B[a]P limit for land application of sludge exists, the contents of B[a]P and PA in 46 sludge samples from 15 cities in the Yangtze River Delta area of China were determined using high performance liquid chromatography （HPLC） coupled with a fluorescence detector after ultrasonic extraction and silica gel cleanup. B[a]P contents ranged from non-detectable to 1.693 mg kg^-1 dry weight （DW）, averaged 0.402 mg kg^-1 DW, and were 〈 1.0 mg kg^-1 DW in most of the sludge samples. PA was found in all the sludge samples analyzed; its contents ranged between 0.028 and 1.355 mg kg^-1 DW, with an average value of 0.298 mg kg^-1 DW. Most of the sludge samples contained 〈 0.5 mg kg^-1 DW PA. All 46 municipal sludge samples analyzed in this study showed B[a]P contents 〈 3.0 mg kg^-1 DW, which is the limit value for sludge applied to agricultural lands in China. The contents and distributions of B[a]P and PA in municipal sludge were related to sludge types, sources and treatment technologies, along with the physical and chemical properties of these pollutants.展开更多
基金National Key Basic Research Program(973Program)of China(2010CB428505)National Natural Science Foundation of China(41230528)Project Funded by the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions
文摘Climate effect caused by urbanization has been an indispensable anthropogenic factor in the research on regional climate change.Based on daily precipitation data,possible effects of precipitation on the development of three city groups in eastern China are discussed.With three classification methods(TP,PD and MODIS land cover),urban and rural stations are identified.The main findings are as follows.Climate effects caused by urbanization are different from place to place.In 1960 to 2009,the urbanization brought more precipitation to the Yangtze River Delta and Pearl River Delta city groups but had no obvious effect on the precipitation of the Beijing-Tianjin-Tangshan city group.The difference of precipitation is slight between urban and suburban areas during slow period of the urbanization from 1960 to 1979.It is more evident in the rapid period(1980 to 2009) that urbanization has positive effects on precipitation in every city group.The difference of precipitation between urban and rural stations is sensitive to the ways of distinguishing rural from urban area,which may cause uncertainties in 1960 to 1979,while it is very different in 1980 to 2009 in which urbanization favors more precipitation in all city groups and their differences in precipitation are not sensitive to the division methods.
基金Project supported by the National Key Basic Research Support Foundation (973 Program) of China (No.2002CB4108010) the Knowledge Innovation Program of the Chinese Academy of Sciences (No.KSCX2-YW-N-038)
文摘To evaluate the contaminated conditions of benzo[alpyrene （B[a]P） and phenanthrene （PA） in sludge and to ascertain whether B[a]P limit for land application of sludge exists, the contents of B[a]P and PA in 46 sludge samples from 15 cities in the Yangtze River Delta area of China were determined using high performance liquid chromatography （HPLC） coupled with a fluorescence detector after ultrasonic extraction and silica gel cleanup. B[a]P contents ranged from non-detectable to 1.693 mg kg^-1 dry weight （DW）, averaged 0.402 mg kg^-1 DW, and were 〈 1.0 mg kg^-1 DW in most of the sludge samples. PA was found in all the sludge samples analyzed; its contents ranged between 0.028 and 1.355 mg kg^-1 DW, with an average value of 0.298 mg kg^-1 DW. Most of the sludge samples contained 〈 0.5 mg kg^-1 DW PA. All 46 municipal sludge samples analyzed in this study showed B[a]P contents 〈 3.0 mg kg^-1 DW, which is the limit value for sludge applied to agricultural lands in China. The contents and distributions of B[a]P and PA in municipal sludge were related to sludge types, sources and treatment technologies, along with the physical and chemical properties of these pollutants.
