A distributed QoS (quality of service) -aware source-specific multicast routing protocol—DQSSMR is proposed to increase the successful join ratio and lower the overhead of the control message in QoS required multicas...A distributed QoS (quality of service) -aware source-specific multicast routing protocol—DQSSMR is proposed to increase the successful join ratio and lower the overhead of the control message in QoS required multicast routing. By an improved searching strategy, the cost of message control is reduced and the successful join ratio is increased. The network load is balanced due to the distributed routing operation and the scalability is enhanced further because of the usage of SSM (source- specific multicast) service model in DQSSMR. The analysis results indicate that DQSSMR performs as expected.展开更多
China has experienced an initial increase and a subsequent decrease in fine particulate matter(PM_(2.5))concentrations since the early 21st century,with substantial heterogeneity across different source contributions....China has experienced an initial increase and a subsequent decrease in fine particulate matter(PM_(2.5))concentrations since the early 21st century,with substantial heterogeneity across different source contributions.This study developed a source-oriented CMAQ model to construct a source-resolved PM_(2.5)concentration database for China during 2000-2020.Subsequently,source-specific health risks and the contributions of key driving factors were systematically evaluated using the piling-up decomposition method.The results indicate that anthropogenic emissions,particularly from industrial sources,were the primary drivers of both the increase in PM_(2.5)from 2000 to 2012(51.8%)and the subsequent decrease from 2012 to 2020(47.6%).Currently,industrial sources remain the largest contributor to PM_(2.5)(about 32%),followed by residential(about 22%)and transportation sources(about 13%).Implementation of two-phase air pollution control measures led to a 20.4%reduction in national premature mortality attributable to PM_(2.5)from 2012 to 2020,although 10.6%of this benefit was offset by changes in population and baseline mortality rates.Throughout 2000-2020,health risks associated with anthropogenic sources consistently exceeded their proportional contribution to PM_(2.5),primarily because these emissions are concentrated in densely populated areas.These findings underscore that,in addition to implementing region-specific emission reduction policies,maintaining stringent controls on anthropogenic emissions,particularly from industrial and transportation sources,is crucial to maximizing future health benefits.展开更多
Identifying potential sources of pharmaceuticals and personal care products(PPCPs)in the environment is critical for the effective control of PPCP contamination.Landfill leachate is an important source of PPCPs in wat...Identifying potential sources of pharmaceuticals and personal care products(PPCPs)in the environment is critical for the effective control of PPCP contamination.Landfill leachate is an important source of PPCPs in water;however,it has barely been involved in source apportionment due to the lack of indicator-PPCPs(i-PPCPs)in landfill leachates.This study provides the first systematic framework for identifying i-PPCPs for landfill leachates based on the wide-scope target monitoring of PPCPs.The number of target PPCPs increased from<20 in previous studies to 68 in the present study.Fifty-nine PPCPs were detected,with median concentrations in leachate samples ranging from below the method quantification limit(MQL)to 41μg/L,and 19 of them were rarely reported previously.A total of 29 target compounds were determined to be PPCPs of high concern by principal component analysis according to multiple criteria,including occurrence,exposure potential,and ecological effect.Coupled with source-specificity and representativeness analysis,erythromycin,gemfibrozil,and albendazole showed a significant difference in their occurrence in leachate compared to other potential sources(untreated and treated municipal wastewater and livestock wastewater)and correlated with total PPCP concentrations;these were recommended as i-PPCPs for leachates.Indicator screening procedure can be used to develop a sophisticated source apportionment method to identify sources of PPCPs from adjacent landfills.展开更多
文摘A distributed QoS (quality of service) -aware source-specific multicast routing protocol—DQSSMR is proposed to increase the successful join ratio and lower the overhead of the control message in QoS required multicast routing. By an improved searching strategy, the cost of message control is reduced and the successful join ratio is increased. The network load is balanced due to the distributed routing operation and the scalability is enhanced further because of the usage of SSM (source- specific multicast) service model in DQSSMR. The analysis results indicate that DQSSMR performs as expected.
基金supported by the National Key R&D Program of China(2022YFC3701105)the National Natural Science Foundation of China(42077194,42061134008,42377098)+1 种基金the Shanghai International Science and Technology Partner-ship Project(21230780200)the Shanghai General Project(23ZR1406100).
文摘China has experienced an initial increase and a subsequent decrease in fine particulate matter(PM_(2.5))concentrations since the early 21st century,with substantial heterogeneity across different source contributions.This study developed a source-oriented CMAQ model to construct a source-resolved PM_(2.5)concentration database for China during 2000-2020.Subsequently,source-specific health risks and the contributions of key driving factors were systematically evaluated using the piling-up decomposition method.The results indicate that anthropogenic emissions,particularly from industrial sources,were the primary drivers of both the increase in PM_(2.5)from 2000 to 2012(51.8%)and the subsequent decrease from 2012 to 2020(47.6%).Currently,industrial sources remain the largest contributor to PM_(2.5)(about 32%),followed by residential(about 22%)and transportation sources(about 13%).Implementation of two-phase air pollution control measures led to a 20.4%reduction in national premature mortality attributable to PM_(2.5)from 2012 to 2020,although 10.6%of this benefit was offset by changes in population and baseline mortality rates.Throughout 2000-2020,health risks associated with anthropogenic sources consistently exceeded their proportional contribution to PM_(2.5),primarily because these emissions are concentrated in densely populated areas.These findings underscore that,in addition to implementing region-specific emission reduction policies,maintaining stringent controls on anthropogenic emissions,particularly from industrial and transportation sources,is crucial to maximizing future health benefits.
基金supported by the National Natural Science Foundation of China(Nos.21777042 and 22076045)the Open Research Fund of State Environmental Protection Key Laboratory of Ecological Effect and Risk Assessment of Chemicals(China)(No.2022KFYB03)+1 种基金the Science and Technology Commission of Shanghai Municipality’s Yangfan Special Project(China)(No.23YF1408400)the project supported by Shanghai Talent Development Funding(China).
文摘Identifying potential sources of pharmaceuticals and personal care products(PPCPs)in the environment is critical for the effective control of PPCP contamination.Landfill leachate is an important source of PPCPs in water;however,it has barely been involved in source apportionment due to the lack of indicator-PPCPs(i-PPCPs)in landfill leachates.This study provides the first systematic framework for identifying i-PPCPs for landfill leachates based on the wide-scope target monitoring of PPCPs.The number of target PPCPs increased from<20 in previous studies to 68 in the present study.Fifty-nine PPCPs were detected,with median concentrations in leachate samples ranging from below the method quantification limit(MQL)to 41μg/L,and 19 of them were rarely reported previously.A total of 29 target compounds were determined to be PPCPs of high concern by principal component analysis according to multiple criteria,including occurrence,exposure potential,and ecological effect.Coupled with source-specificity and representativeness analysis,erythromycin,gemfibrozil,and albendazole showed a significant difference in their occurrence in leachate compared to other potential sources(untreated and treated municipal wastewater and livestock wastewater)and correlated with total PPCP concentrations;these were recommended as i-PPCPs for leachates.Indicator screening procedure can be used to develop a sophisticated source apportionment method to identify sources of PPCPs from adjacent landfills.
