The cluster analysis method needs continuous improvement and perfection in the research and application of the spatial differentiation and change of pollutants.In this paper,the date of monthly highest concentration o...The cluster analysis method needs continuous improvement and perfection in the research and application of the spatial differentiation and change of pollutants.In this paper,the date of monthly highest concentration of ozone(O_(3))and the concentration value of that day were selected as the similarity coefficient between classes.Single-factor cluster analysis was performed on O_(3)during 2016-2019 and the COVID-19 outbreak of 2020 in Hunan Province using the Ward method.The clustering results showed that the spatial distribution of atmospheric O_(3)in the 14 regions of Hunan Province was most suitable to be classified according to class III clustering areas.That is,the Changsha-Zhuzhou-Xiangtan urban agglomeration was the center,and the high-value area was in northern Hunan.The transition area was in central and southern Hunan,while the low-value area was centered in western Hunan.The partition results were in good agreement with the homogeneous subset of one-way ANOVA and the distribution of monitoring values during the same period.The comparison showed that the inter-class plates in the two periods corresponded well,and the intra-class area showed a continuous geographical distribution,and there were dynamic changes in the spatial differentiation of the O_(3)plates in different periods.In 2020,the center of the O_(3)high-value area plate in Hunan Province moved eastward and extended southward,focusing on the middle and lower reaches of the Xiangjiang River basin,and extending to the upstream area;the regional plate in the transition area expanded significantly;the low-value area plate shrank to the two cities in western Hunan.The abnormal emissions and abnormal climate during the COVID-19 epidemic had an impact on the spatial differentiation of O_(3)in Hunan Province.展开更多
Effects of conservation methods of water samples on determination of total phosphorus were analyzed from aspects of methods of adding conserving agent, SS concentration, natural sedimentation time, conservation temper...Effects of conservation methods of water samples on determination of total phosphorus were analyzed from aspects of methods of adding conserving agent, SS concentration, natural sedimentation time, conservation temperature and time. The results showed that SS concentration in water and natural sedimentation time had the greatest impact on the determination of total phosphorus, while the influence of methods of adding conserving agent, conservation temperature and time was relatively smaller. TP concentration in water samples conserved irregularly was higher than the standard value due to the existence of SS and microorganisms in water, and the deviation became larger with the increase of SS concentration in water. In addition, quality control measures and matters needing attention during the conservation process of water samples were put forward to improve the accuracy of TP concentration.展开更多
Based on the monitored data of references, EANET and the CMAQ （4.7.1） model scenado simulations, the annual average concentration of SO2 in China in the recent 10 years and the contribution of China＇s SO2 emissions...Based on the monitored data of references, EANET and the CMAQ （4.7.1） model scenado simulations, the annual average concentration of SO2 in China in the recent 10 years and the contribution of China＇s SO2 emissions to SO2 concentration and sulfur deposition at various sites in Japan downwind were analyzed. The results showed that from 2001 to 2009 annual average concentration of SO2 was 0 -150 μg/m^3 and showed a decreasing trend on the whole in China. The correlation coefficient of annual average concentration of SO2 at different sites in Japan and China＇s SO2 emissions was lower than that of annual average concentration and emission of SO2 in China＇s cities on the whole, showing that SO2 discharged in China had small impact on SO2 concentration in Japan. The contribution rate of China＇s SO2 emissions to annual average concentration of SO2 at various sites in Japan in 2010 was 7.5% -44.0%, averaging 22.6% ; the annual average volume concentration of SO2 at different sites in Japan caused by China＇s SO2 emissions was 0 -0.5 × 10^-9. The contribution rate of China＇s SO2 emissions to sulfur deposition at various sites in Japan in 2010 varied from 8.0% to 41.0%, averaging 22.1%.展开更多
文摘The cluster analysis method needs continuous improvement and perfection in the research and application of the spatial differentiation and change of pollutants.In this paper,the date of monthly highest concentration of ozone(O_(3))and the concentration value of that day were selected as the similarity coefficient between classes.Single-factor cluster analysis was performed on O_(3)during 2016-2019 and the COVID-19 outbreak of 2020 in Hunan Province using the Ward method.The clustering results showed that the spatial distribution of atmospheric O_(3)in the 14 regions of Hunan Province was most suitable to be classified according to class III clustering areas.That is,the Changsha-Zhuzhou-Xiangtan urban agglomeration was the center,and the high-value area was in northern Hunan.The transition area was in central and southern Hunan,while the low-value area was centered in western Hunan.The partition results were in good agreement with the homogeneous subset of one-way ANOVA and the distribution of monitoring values during the same period.The comparison showed that the inter-class plates in the two periods corresponded well,and the intra-class area showed a continuous geographical distribution,and there were dynamic changes in the spatial differentiation of the O_(3)plates in different periods.In 2020,the center of the O_(3)high-value area plate in Hunan Province moved eastward and extended southward,focusing on the middle and lower reaches of the Xiangjiang River basin,and extending to the upstream area;the regional plate in the transition area expanded significantly;the low-value area plate shrank to the two cities in western Hunan.The abnormal emissions and abnormal climate during the COVID-19 epidemic had an impact on the spatial differentiation of O_(3)in Hunan Province.
文摘Effects of conservation methods of water samples on determination of total phosphorus were analyzed from aspects of methods of adding conserving agent, SS concentration, natural sedimentation time, conservation temperature and time. The results showed that SS concentration in water and natural sedimentation time had the greatest impact on the determination of total phosphorus, while the influence of methods of adding conserving agent, conservation temperature and time was relatively smaller. TP concentration in water samples conserved irregularly was higher than the standard value due to the existence of SS and microorganisms in water, and the deviation became larger with the increase of SS concentration in water. In addition, quality control measures and matters needing attention during the conservation process of water samples were put forward to improve the accuracy of TP concentration.
基金Supported by the National Natural Science Foundation of China(41373131)National Key Technology R&D Program(2014BAC23B03)Major Tender Project of Social Science Foundation of Human Province,China(14DA12)
文摘Based on the monitored data of references, EANET and the CMAQ （4.7.1） model scenado simulations, the annual average concentration of SO2 in China in the recent 10 years and the contribution of China＇s SO2 emissions to SO2 concentration and sulfur deposition at various sites in Japan downwind were analyzed. The results showed that from 2001 to 2009 annual average concentration of SO2 was 0 -150 μg/m^3 and showed a decreasing trend on the whole in China. The correlation coefficient of annual average concentration of SO2 at different sites in Japan and China＇s SO2 emissions was lower than that of annual average concentration and emission of SO2 in China＇s cities on the whole, showing that SO2 discharged in China had small impact on SO2 concentration in Japan. The contribution rate of China＇s SO2 emissions to annual average concentration of SO2 at various sites in Japan in 2010 was 7.5% -44.0%, averaging 22.6% ; the annual average volume concentration of SO2 at different sites in Japan caused by China＇s SO2 emissions was 0 -0.5 × 10^-9. The contribution rate of China＇s SO2 emissions to sulfur deposition at various sites in Japan in 2010 varied from 8.0% to 41.0%, averaging 22.1%.
