In order to understand the relative importance of anthropogenic and biological sources of carbonaceous aerosols in Northeast Asia,we measured total carbon(TC)and water-soluble organic carbon(WSOC)and their stable carb...In order to understand the relative importance of anthropogenic and biological sources of carbonaceous aerosols in Northeast Asia,we measured total carbon(TC)and water-soluble organic carbon(WSOC)and their stable carbon isotope ratios(d^(13)C)in total suspended particulates collected from Sapporo,northern Japan(43.07°N,141.36°E)over a 1-year period(during 2 September 2009and 5 October 2010).Temporal variations of TC showed a gradual decrease from mid-autumn to winter followed by a gradual increase to growing season with a peak in early summer.Both d^(13)C_(TC)and d^(13)C_(WSOC)showed very similar temporal trends with a gradual enrichment of^(13)C from mid-autumn to winter followed by a depletion in the^(13)C to early summer and thereafter it remained stable,except for few cases.Based on the results obtained together with the air mass trajectories,we found that biogenic emissions including biological particles(e.g.,pollen)and secondary organic aerosol formation from biogenic volatile organic compounds are the important sources of carbonaceous aerosols in spring/summer whereas fungal spores from soil and biomass burning and enhanced fossil fuel combustion contribute significantly in autumn/winter and in winter,respectively,in Northeast Asia.展开更多
In order to discover the relation between rock-soil thermal properties and strata during the process of engineering investigation,the authors studied the measuring principle of Thermal Conductivity Scanner( TCS)and me...In order to discover the relation between rock-soil thermal properties and strata during the process of engineering investigation,the authors studied the measuring principle of Thermal Conductivity Scanner( TCS)and measured the thermal properties of 45 drilling samples from Qinghai with TCS in the laboratory. The results show that the specific heat capacity( SHC) decreases while the thermal conductivity( TC) increases with the increase of the depth. With the lithological change,the specific heat capacity and thermal conductivity have the opposite trend. The depth and lithology have a greater influence on the thermal conductivity than the specific heat capacity.展开更多
Trends of the tropical cyclones (TCs) influence on China and its four subregions,namely the South China (SC),East China (EC),Northeast China (NEC),and China's inland area (CI),are detected by applying quantile reg...Trends of the tropical cyclones (TCs) influence on China and its four subregions,namely the South China (SC),East China (EC),Northeast China (NEC),and China's inland area (CI),are detected by applying quantile regression to the CMA-STI tropical cyclone best track and related severe wind and precipitation observation datasets.The results indicate that in the past 50 years,the number of TCs affecting China and its four subregions has remained steady,except that the frequency in extremely active years has decreased not only in China as a whole,but also in NEC.In addition,TC activity is found to have weakened over the northwest South China Sea,Guangdong,and Shandong Peninsula.However,the most important changes in seasonality are found in the first quartiles of the number of days of TCs affecting CI.While the extreme values of sustained winds all have decreasing trends,the extreme values of wind gusts are completely different not only among different orders of extreme values,but also among different subregions.However,the trends of extreme TC rainfall,namely the maximum storm precipitation and the maximum 1-h precipitation,are not significant.展开更多
基金supported by the Environment Research and Technology Development Fund(B-0903)of the Ministry of the Environment,Japan,the Japan Society for the Promotion of Science(JSPS)Japan through Grant-in-Aid No.24221001985 Project of National Key Universities,Tianjin University,China
文摘In order to understand the relative importance of anthropogenic and biological sources of carbonaceous aerosols in Northeast Asia,we measured total carbon(TC)and water-soluble organic carbon(WSOC)and their stable carbon isotope ratios(d^(13)C)in total suspended particulates collected from Sapporo,northern Japan(43.07°N,141.36°E)over a 1-year period(during 2 September 2009and 5 October 2010).Temporal variations of TC showed a gradual decrease from mid-autumn to winter followed by a gradual increase to growing season with a peak in early summer.Both d^(13)C_(TC)and d^(13)C_(WSOC)showed very similar temporal trends with a gradual enrichment of^(13)C from mid-autumn to winter followed by a depletion in the^(13)C to early summer and thereafter it remained stable,except for few cases.Based on the results obtained together with the air mass trajectories,we found that biogenic emissions including biological particles(e.g.,pollen)and secondary organic aerosol formation from biogenic volatile organic compounds are the important sources of carbonaceous aerosols in spring/summer whereas fungal spores from soil and biomass burning and enhanced fossil fuel combustion contribute significantly in autumn/winter and in winter,respectively,in Northeast Asia.
基金Supported by National High Technology Research and Development Program of China(863 Project)(No.2012AA052801)National Natural ScienceFoundation of China(No.41372239)Specialized Research Fund for the Doctoral Program of Higher Education(No.20110061110055)
文摘In order to discover the relation between rock-soil thermal properties and strata during the process of engineering investigation,the authors studied the measuring principle of Thermal Conductivity Scanner( TCS)and measured the thermal properties of 45 drilling samples from Qinghai with TCS in the laboratory. The results show that the specific heat capacity( SHC) decreases while the thermal conductivity( TC) increases with the increase of the depth. With the lithological change,the specific heat capacity and thermal conductivity have the opposite trend. The depth and lithology have a greater influence on the thermal conductivity than the specific heat capacity.
基金sponsored by the Climate Change Specialized Foundation of the China Meteorological Administration(Grant No.CCSF-09-10)the National Natural Science Foundation of China(Grant Nos.40805040 and 41075071)
文摘Trends of the tropical cyclones (TCs) influence on China and its four subregions,namely the South China (SC),East China (EC),Northeast China (NEC),and China's inland area (CI),are detected by applying quantile regression to the CMA-STI tropical cyclone best track and related severe wind and precipitation observation datasets.The results indicate that in the past 50 years,the number of TCs affecting China and its four subregions has remained steady,except that the frequency in extremely active years has decreased not only in China as a whole,but also in NEC.In addition,TC activity is found to have weakened over the northwest South China Sea,Guangdong,and Shandong Peninsula.However,the most important changes in seasonality are found in the first quartiles of the number of days of TCs affecting CI.While the extreme values of sustained winds all have decreasing trends,the extreme values of wind gusts are completely different not only among different orders of extreme values,but also among different subregions.However,the trends of extreme TC rainfall,namely the maximum storm precipitation and the maximum 1-h precipitation,are not significant.
