This paper introduces the problems emerged in the developing process of Nanning Medium-voltage distribution network to adapt the progress of HV network. These problems are: (1) unreasonable structure (large amount of ...This paper introduces the problems emerged in the developing process of Nanning Medium-voltage distribution network to adapt the progress of HV network. These problems are: (1) unreasonable structure (large amount of radical type 10 kV lines); (2) one 10 kV line for each customer (causing difficulties for line corridors); (3) circuit breaker are widely used for MV customers (result in complicated substation structure); (4) lots of overhead 10 kV lines in urban area. Ring circuit, insulated cables, load break switches, and fast acting fuses etc. advanced technologies are proposed for the retrofit of urban distribution network.展开更多
This paper focused on the pollution characteristics, sources and lung cancer risk of atmospheric polycyclic aromatic hydrocarbons （PAHs） in a new urban district of Nanjing, China. Gaseous and aerosol PM2.5 （particu...This paper focused on the pollution characteristics, sources and lung cancer risk of atmospheric polycyclic aromatic hydrocarbons （PAHs） in a new urban district of Nanjing, China. Gaseous and aerosol PM2.5 （particulate matter with aerodynamic diameter smaller than 2.S μm） samples were collected in spring of 2015. Sixteen PAHs were extracted and analyzed after sampling. Firstly, arithmetic mean concentrations of PAHs and BaPeq （benzo[a]pyrene equivalent） were calculated. The mean concentrations of PAHs were 29.26 ± 14.13,18.14 ± 5.37 and 48.47 ± 16.03 ng/m3 in gas phase, particle phase and both phases, respectively. The mean concentrations of BaPeq were 0.87 ± 0.51, 2.71 ± 2.17 and 4.06 ± 2.31 ng/m3 in gas phase, particle phase and both phases, respectively. Secondly, diagnostic ratios and principal component analysis were adopted to identify the sources of PAHs and the outcomes were the same： traffic exhaust was the predominant source followed by fuel combustion and industrial process. Finally, incremental lung cancer risk （ILCR） induced by whole year inhalation exposure to PAHs for population groups of different age and gender were estimated based on a Monte Carlo simulation. ILCR values caused by particle phase PAHs were greater than those caused by gas phase PAHs. ILCR values for adults were greater than those for other age groups. ILCR values caused by total （gas ＋ particle） PAHs for diverse groups were all greater than the significant level （10-6）, indicating high potential lung cancer risk. Sensitivity analysis results showed that cancer slope factor for BaP inhalation exposure and BaPeq concentration had greater impact than body weight and inhalation rate on the ILCR.展开更多
文摘This paper introduces the problems emerged in the developing process of Nanning Medium-voltage distribution network to adapt the progress of HV network. These problems are: (1) unreasonable structure (large amount of radical type 10 kV lines); (2) one 10 kV line for each customer (causing difficulties for line corridors); (3) circuit breaker are widely used for MV customers (result in complicated substation structure); (4) lots of overhead 10 kV lines in urban area. Ring circuit, insulated cables, load break switches, and fast acting fuses etc. advanced technologies are proposed for the retrofit of urban distribution network.
基金supported by the National Natural Science Foundation of China(No.41001344)the China Postdoctoral Science Foundation Funded Project(2013M541696)+5 种基金the Jiangsu Planned Projects for Postdoctoral Research Funds(No.1301040C)the Program of Natural Science Research of Jiangsu Higher Education Institutions of China(No.13KJB610008)the Program of State Key Laboratory of Environmental Criteria and Risk Assessment,Chinese Research Academy of Environmental Sciences(No.SKLECRA2013OFP07)the Scientific Research Foundation of the High-level Personnel of Nanjing Normal University(No.2012105XGQ0102)the Program of Graduate Education Reform and Practice of Nanjing Normal University(No.1812000002A521)the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.164320H116)
文摘This paper focused on the pollution characteristics, sources and lung cancer risk of atmospheric polycyclic aromatic hydrocarbons （PAHs） in a new urban district of Nanjing, China. Gaseous and aerosol PM2.5 （particulate matter with aerodynamic diameter smaller than 2.S μm） samples were collected in spring of 2015. Sixteen PAHs were extracted and analyzed after sampling. Firstly, arithmetic mean concentrations of PAHs and BaPeq （benzo[a]pyrene equivalent） were calculated. The mean concentrations of PAHs were 29.26 ± 14.13,18.14 ± 5.37 and 48.47 ± 16.03 ng/m3 in gas phase, particle phase and both phases, respectively. The mean concentrations of BaPeq were 0.87 ± 0.51, 2.71 ± 2.17 and 4.06 ± 2.31 ng/m3 in gas phase, particle phase and both phases, respectively. Secondly, diagnostic ratios and principal component analysis were adopted to identify the sources of PAHs and the outcomes were the same： traffic exhaust was the predominant source followed by fuel combustion and industrial process. Finally, incremental lung cancer risk （ILCR） induced by whole year inhalation exposure to PAHs for population groups of different age and gender were estimated based on a Monte Carlo simulation. ILCR values caused by particle phase PAHs were greater than those caused by gas phase PAHs. ILCR values for adults were greater than those for other age groups. ILCR values caused by total （gas ＋ particle） PAHs for diverse groups were all greater than the significant level （10-6）, indicating high potential lung cancer risk. Sensitivity analysis results showed that cancer slope factor for BaP inhalation exposure and BaPeq concentration had greater impact than body weight and inhalation rate on the ILCR.
