Ship emissions contribute considerably to air pollution and are expected to decline under domestic policies and international cooperation such as green shipping corridors(GSCs).However,evaluation of the emission reduc...Ship emissions contribute considerably to air pollution and are expected to decline under domestic policies and international cooperation such as green shipping corridors(GSCs).However,evaluation of the emission reduction potential by the Domestic Emission Control Area(DECA)policy and GSC cooperation is still lacking.Here,a series of multi-year high spatiotemporal ship emission inventories around Hainan,a representative island province of China,were developed with the state-of-the-art Shipping Emission Inventory Model.The improved origin-destination identification algorithm allowed emission allocation to port level.The emission reduction potential of the DECA policy and Hainan's joining GSCwas analyzed.In 2022,ship emission intensity in waters 12 Nm from Hainan(Hainan-12Nm)were 6.4%-7.4% of that in waters 12 Nm from China.From 2019 to 2022,Hainan-12Nm emissions dropped by 66.7%-77.8% for SO_(2) and PM2.5.Ideally,with adequate ultra-low-sulfur fuel,DECA can reduce SO_(2) and PM2.5 emissions by 16.6% and 22.4% yearly compared with no-DECA scenario.However,emission reduction would drop markedly if ultra-low-sulfur fuel is short in supply.Emissions of voyages passing through 200 Nm from Hainan took up 1%-4%of international shipping emissions,implying great emission reduction potential for Hainan's establishing GSCs,especially considering the flourishing South-South trade.This study provides a thorough assessment of the current state of shipping emissions around Hainan as well as offers excellent data support for Hainan to further advance the future upgrade of ship emission management policies.展开更多
This paper presents an air quality simulation model that incorporates shipping activities and weather conditions,with a case study of Hainan Island to examine the impact of ship emissions on air quality.The findings r...This paper presents an air quality simulation model that incorporates shipping activities and weather conditions,with a case study of Hainan Island to examine the impact of ship emissions on air quality.The findings reveal that the density of automatic identification system(AIS)signals is particularly high in the southern coastal regions.The results showed that the annual ship emissions recorded the highest density of 896.7 tons/0.01°,49.8 tons/0.01°,1139.7 tons/0.01°,and 122,000 tons/0.01°for sulfur oxides(SO_(x)),particulate matter(PM),nitrogen oxides(NOx),and carbon dioxide(CO_(2)),respectively.Furthermore,the partial distributions of these emissions were not significantly affected by the seasons.Ships within twelve nautical miles of Hainan coastlines emit approximately 2817.7 tons of SO_(x),14,686.4 tons of NO_(x),630.4 tons of PM_(2.5),and 416.9 tons of hydrocarbons(HC)annually.These emissions are primarily concentrated in the sea areas surrounding the ports of Haikou,Yangpu,Basuo,and Sanya.Ships manufactured between 2000 and 2010 have contributed significantly to air pollution,with SO_(x) and HC emissions accounting for approximately 51%and 56% of total emissions,respectively.However,for shipsmanufactured after 2016,these proportions have dropped to approximately 10%.In terms of air pollutants fromship emissions in Hainan Island,the spatial distribution of their contributions is significantly uneven.The impact of PM2.5 differs significantly depending on the season,with the concentrations being substantially higher during Spring.However,the proportions of O3 and other pollutants do not vary significantly,except during Spring.展开更多
Based on one-year observation,the concentration,sources,and potential source areas of volatile organic compounds(VOCs)were comprehensively analyzed to investigate the pollution characteristics of ambient VOCs in Haiko...Based on one-year observation,the concentration,sources,and potential source areas of volatile organic compounds(VOCs)were comprehensively analyzed to investigate the pollution characteristics of ambient VOCs in Haikou,China.The results showed that the annual average concentration of total VOCs(TVOCs)was 11.4 ppb V,and the composition was dominated by alkanes(8.2 ppb V,71.4%)and alkenes(1.3 ppb V,20.5%).The diurnal variation in the concentration of dominant VOC species showed a distinct bimodal distribution with peaks in the morning and evening.The greatest contribution to ozone formation potential(OFP)was made by alkenes(51.6%),followed by alkanes(27.2%).The concentrations of VOCs and nitrogen dioxide(NO_(2))in spring and summer were low,and it was difficult to generate high ozone(O_(3))concentrations through photochemical reactions.The significant increase in O_(3)concentrations in autumn and winter was mainly related to the transmission of pollutants from the northeast.Traffic sources(40.1%),industrial sources(19.4%),combustion sources(18.6%),solvent usage sources(15.5%)and plant sources(6.4%)were identified as major sources of VOCs through the positive matrix factorization(PMF)model.The southeastern coastal areas of China were identified as major potential source areas of VOCs through the potential source contribution function(PSCF)and concentration-weighted trajectory(CWT)models.Overall,the concentration of ambient VOCs in Haikou was strongly influenced by traffic sources and long-distance transport,and the control of VOCs emitted from vehicles should be strengthened to reduce the active species of ambient VOCs in Haikou,thereby reducing the generation of O_(3).展开更多
The ambient air quality standard(AAQS)is a vital policy instrument for protecting the environment and human health.Hainan Province is at the forefront of China's efforts to protect its ecological environment,with ...The ambient air quality standard(AAQS)is a vital policy instrument for protecting the environment and human health.Hainan Province is at the forefront of China's efforts to protect its ecological environment,with an official goal to achieve world-leading air quality by 2035.However,neither the national AAQS nor the World Health Organization guideline offers sufficient guidance for improving air quality in Hainan because Hainan has well met the former while the latter is excessively stringent.Consequently,the establishment of Hainan's local AAQS becomes imperative.Nonetheless,research regarding the development of local AAQS is scarce,especially in comparatively more polluted countries such as China.The relatively high background values and significant interannual fluctuations in air pollutant concentrations in Hainan present challenges in the development of local AAQS.Our research proposes a world-class local AAQS of Hainan Province by reviewing the AAQS in major countries or regions worldwide,analyzing the influence of different statistical forms,and carefully evaluating the attainability of the standard.In the proposed AAQS,the annual mean concentration limit for PM2.5,the annual 95th percentile of daily maximum 8-h mean(MDA8)concentration limit for O_(3),and the peak season concentration limit for O_(3) are set at 10,120,and 85μg/m^(3),respectively.Our study indicates that,with effective control policies,Hainan is projected to achieve compliance with the new standard by 2035.The implementation of the local AAQS is estimated to avoid 1,526(1,253–1,789)and 259(132–501)premature deaths attributable to longterm exposure to PM2.5 and O_(3) in Hainan in 2035,respectively.展开更多
The microspheres/nanosheets of the ZnSe were prepared by solvothermal route.The morphological,structural,optical,as well as photocatalytic properties of the ZnSe products were studied.SEM and TEM results showed that m...The microspheres/nanosheets of the ZnSe were prepared by solvothermal route.The morphological,structural,optical,as well as photocatalytic properties of the ZnSe products were studied.SEM and TEM results showed that morphologies of the products were sensitive to the presence of water or not,and a mechanism was proposed.The products shows a weak blue emission band centered at 476 nm,which is attributed to the near-band-edge emission of the products,and the strong and broad peak at 520 nm is attributed to a defect-related emission.The PL and XRD results indicate that ZnSe microspheres have high crystalline and few defects compared with ZnSe nanosheets,the degradation for Rhodamine 6G shows that the photoactivity of ZnSe nanosheets is nearly twice that of ZnSe microspheres.Therefore,the decrease of defects implies the decrease of photocatalytic activity,and nanosheets is more suitable for the degradation of Rhodamine 6G.展开更多
The ever-changing environment and complex combat missions create new demands for the formation of mission groups of unmanned combat agents.This study aims to address the problem of dynamic construction of mission grou...The ever-changing environment and complex combat missions create new demands for the formation of mission groups of unmanned combat agents.This study aims to address the problem of dynamic construction of mission groups under new requirements.Agents are heterogeneous,and a group formation method must dynamically form new groups in circumstances where missions are constantly being explored.In our method,a group formation strategy that combines heuristic rules and response threshold models is proposed to dynamically adjust the members of the mission group and adapt to the needs of new missions.The degree of matching between the mission requirements and the group’s capabilities,and the communication cost of group formation are used as indicators to evaluate the quality of the group.The response threshold method and the ant colony algorithm are selected as the comparison algorithms in the simulations.The results show that the grouping scheme obtained by the proposed method is superior to those of the comparison methods.展开更多
Graphene,as a steady two dimensional(2D)carbon material,possesses intriguing physical and chemical properties,which arouses great interests of scientists for its applications in enormous fields.In particular,graphene ...Graphene,as a steady two dimensional(2D)carbon material,possesses intriguing physical and chemical properties,which arouses great interests of scientists for its applications in enormous fields.In particular,graphene and graphene oxide have been widely used for drug delivery and DNA detection based onπ-πstacking and hydrophobic interactions.Besides,graphene with fluorescent molecules or nanoparticles and graphene quantum dots have also been frequently applied as fluorescent probe.In this article,advances of graphene and graphene oxide on biomedical applications will be highlighted from the perspective of biomolecular interaction,cell imaging,drug delivery,and toxicity.展开更多
基金supported by the National Natural Science Foundation of China(No.42325505)the National Key R&D Program of China(No.2022YFC3704200)the Tsinghua University Initiative Scientific Research Program.
文摘Ship emissions contribute considerably to air pollution and are expected to decline under domestic policies and international cooperation such as green shipping corridors(GSCs).However,evaluation of the emission reduction potential by the Domestic Emission Control Area(DECA)policy and GSC cooperation is still lacking.Here,a series of multi-year high spatiotemporal ship emission inventories around Hainan,a representative island province of China,were developed with the state-of-the-art Shipping Emission Inventory Model.The improved origin-destination identification algorithm allowed emission allocation to port level.The emission reduction potential of the DECA policy and Hainan's joining GSCwas analyzed.In 2022,ship emission intensity in waters 12 Nm from Hainan(Hainan-12Nm)were 6.4%-7.4% of that in waters 12 Nm from China.From 2019 to 2022,Hainan-12Nm emissions dropped by 66.7%-77.8% for SO_(2) and PM2.5.Ideally,with adequate ultra-low-sulfur fuel,DECA can reduce SO_(2) and PM2.5 emissions by 16.6% and 22.4% yearly compared with no-DECA scenario.However,emission reduction would drop markedly if ultra-low-sulfur fuel is short in supply.Emissions of voyages passing through 200 Nm from Hainan took up 1%-4%of international shipping emissions,implying great emission reduction potential for Hainan's establishing GSCs,especially considering the flourishing South-South trade.This study provides a thorough assessment of the current state of shipping emissions around Hainan as well as offers excellent data support for Hainan to further advance the future upgrade of ship emission management policies.
基金supported by the National Key Research and Development Program of China(No.2022YFC3704200)the National Natural Science Foundation of China(No.52306128)+5 种基金the Major Program of Science and Technology of Hainan Province,China(No.ZDKJ202007)the Innovation Platform for Academicians of Hainan Province(No.YSPTZX202205)the Youth Innovation Foundation of Hainan Research Academy of Environmental Sciences,China(No.QNCX2021002)the Central Guiding Local Science and Technology Development Fund Projects(No.236Z4001G)the Natural Science Basic Research Program of Shaanxi(No.2023-JC-QN-0517)the support from Energy Foundation China.
文摘This paper presents an air quality simulation model that incorporates shipping activities and weather conditions,with a case study of Hainan Island to examine the impact of ship emissions on air quality.The findings reveal that the density of automatic identification system(AIS)signals is particularly high in the southern coastal regions.The results showed that the annual ship emissions recorded the highest density of 896.7 tons/0.01°,49.8 tons/0.01°,1139.7 tons/0.01°,and 122,000 tons/0.01°for sulfur oxides(SO_(x)),particulate matter(PM),nitrogen oxides(NOx),and carbon dioxide(CO_(2)),respectively.Furthermore,the partial distributions of these emissions were not significantly affected by the seasons.Ships within twelve nautical miles of Hainan coastlines emit approximately 2817.7 tons of SO_(x),14,686.4 tons of NO_(x),630.4 tons of PM_(2.5),and 416.9 tons of hydrocarbons(HC)annually.These emissions are primarily concentrated in the sea areas surrounding the ports of Haikou,Yangpu,Basuo,and Sanya.Ships manufactured between 2000 and 2010 have contributed significantly to air pollution,with SO_(x) and HC emissions accounting for approximately 51%and 56% of total emissions,respectively.However,for shipsmanufactured after 2016,these proportions have dropped to approximately 10%.In terms of air pollutants fromship emissions in Hainan Island,the spatial distribution of their contributions is significantly uneven.The impact of PM2.5 differs significantly depending on the season,with the concentrations being substantially higher during Spring.However,the proportions of O3 and other pollutants do not vary significantly,except during Spring.
基金supported by the Major Program of Science and Technology of Hainan Province,China(No.ZDKJ202007)the Special Foundation of Government Financial of Hainan Province,China(No.ZC2018-196)the Youth Innovation Foundation of Hainan Research Academy of Environmental Sciences,China(No.QNCX2021002)。
文摘Based on one-year observation,the concentration,sources,and potential source areas of volatile organic compounds(VOCs)were comprehensively analyzed to investigate the pollution characteristics of ambient VOCs in Haikou,China.The results showed that the annual average concentration of total VOCs(TVOCs)was 11.4 ppb V,and the composition was dominated by alkanes(8.2 ppb V,71.4%)and alkenes(1.3 ppb V,20.5%).The diurnal variation in the concentration of dominant VOC species showed a distinct bimodal distribution with peaks in the morning and evening.The greatest contribution to ozone formation potential(OFP)was made by alkenes(51.6%),followed by alkanes(27.2%).The concentrations of VOCs and nitrogen dioxide(NO_(2))in spring and summer were low,and it was difficult to generate high ozone(O_(3))concentrations through photochemical reactions.The significant increase in O_(3)concentrations in autumn and winter was mainly related to the transmission of pollutants from the northeast.Traffic sources(40.1%),industrial sources(19.4%),combustion sources(18.6%),solvent usage sources(15.5%)and plant sources(6.4%)were identified as major sources of VOCs through the positive matrix factorization(PMF)model.The southeastern coastal areas of China were identified as major potential source areas of VOCs through the potential source contribution function(PSCF)and concentration-weighted trajectory(CWT)models.Overall,the concentration of ambient VOCs in Haikou was strongly influenced by traffic sources and long-distance transport,and the control of VOCs emitted from vehicles should be strengthened to reduce the active species of ambient VOCs in Haikou,thereby reducing the generation of O_(3).
基金supported by the National Key R&D Program of China(2022YFC3700702)the Energy Foundation,and the Tsinghua-Toyota Joint Research Institute Inter-disciplinary Program.
文摘The ambient air quality standard(AAQS)is a vital policy instrument for protecting the environment and human health.Hainan Province is at the forefront of China's efforts to protect its ecological environment,with an official goal to achieve world-leading air quality by 2035.However,neither the national AAQS nor the World Health Organization guideline offers sufficient guidance for improving air quality in Hainan because Hainan has well met the former while the latter is excessively stringent.Consequently,the establishment of Hainan's local AAQS becomes imperative.Nonetheless,research regarding the development of local AAQS is scarce,especially in comparatively more polluted countries such as China.The relatively high background values and significant interannual fluctuations in air pollutant concentrations in Hainan present challenges in the development of local AAQS.Our research proposes a world-class local AAQS of Hainan Province by reviewing the AAQS in major countries or regions worldwide,analyzing the influence of different statistical forms,and carefully evaluating the attainability of the standard.In the proposed AAQS,the annual mean concentration limit for PM2.5,the annual 95th percentile of daily maximum 8-h mean(MDA8)concentration limit for O_(3),and the peak season concentration limit for O_(3) are set at 10,120,and 85μg/m^(3),respectively.Our study indicates that,with effective control policies,Hainan is projected to achieve compliance with the new standard by 2035.The implementation of the local AAQS is estimated to avoid 1,526(1,253–1,789)and 259(132–501)premature deaths attributable to longterm exposure to PM2.5 and O_(3) in Hainan in 2035,respectively.
基金financially supported by the National“973”Program(Nos.2007CB936000 and 2010CB933900)the NSFC(No.20774029 and No.20906055)of ChinaChina postdoctoral science foundation(No.20100470131).
文摘The microspheres/nanosheets of the ZnSe were prepared by solvothermal route.The morphological,structural,optical,as well as photocatalytic properties of the ZnSe products were studied.SEM and TEM results showed that morphologies of the products were sensitive to the presence of water or not,and a mechanism was proposed.The products shows a weak blue emission band centered at 476 nm,which is attributed to the near-band-edge emission of the products,and the strong and broad peak at 520 nm is attributed to a defect-related emission.The PL and XRD results indicate that ZnSe microspheres have high crystalline and few defects compared with ZnSe nanosheets,the degradation for Rhodamine 6G shows that the photoactivity of ZnSe nanosheets is nearly twice that of ZnSe microspheres.Therefore,the decrease of defects implies the decrease of photocatalytic activity,and nanosheets is more suitable for the degradation of Rhodamine 6G.
基金Project supported by the National Natural Science Foundation of China(No.61773066)the Foundation of China Academy of Railway Sciences Corporation Limited(No.2019YJ071)。
文摘The ever-changing environment and complex combat missions create new demands for the formation of mission groups of unmanned combat agents.This study aims to address the problem of dynamic construction of mission groups under new requirements.Agents are heterogeneous,and a group formation method must dynamically form new groups in circumstances where missions are constantly being explored.In our method,a group formation strategy that combines heuristic rules and response threshold models is proposed to dynamically adjust the members of the mission group and adapt to the needs of new missions.The degree of matching between the mission requirements and the group’s capabilities,and the communication cost of group formation are used as indicators to evaluate the quality of the group.The response threshold method and the ant colony algorithm are selected as the comparison algorithms in the simulations.The results show that the grouping scheme obtained by the proposed method is superior to those of the comparison methods.
基金supported by the NSFC(20906055)National"973 Program"(No.2010CB933900)the State key laboratory of bioreactor engineering(No.2060204).
文摘Graphene,as a steady two dimensional(2D)carbon material,possesses intriguing physical and chemical properties,which arouses great interests of scientists for its applications in enormous fields.In particular,graphene and graphene oxide have been widely used for drug delivery and DNA detection based onπ-πstacking and hydrophobic interactions.Besides,graphene with fluorescent molecules or nanoparticles and graphene quantum dots have also been frequently applied as fluorescent probe.In this article,advances of graphene and graphene oxide on biomedical applications will be highlighted from the perspective of biomolecular interaction,cell imaging,drug delivery,and toxicity.
