Ultrasonic humidifiers are commonly used in households to maintain indoor humidity and generate a large number of droplets or spray aerosols.However,there have been various health concerns associated with humidifier u...Ultrasonic humidifiers are commonly used in households to maintain indoor humidity and generate a large number of droplets or spray aerosols.However,there have been various health concerns associated with humidifier use,largely due to aerosols generated during operation.Here,we investigated the size distribution,chemical composition,and charged fraction of aerosol particles emitted from commercial ultrasonic humidifiers.Heavy metals in water used for humidifiers were found to be highly enriched in the ultrasonic humidifier aerosols(UHA),with the enrichment factors ranging from 102 to 107.This enrichment may pose health concerns for the building occupants,as UHA concentrations of up to 106 particles/cm^(3) or 3 mg/m^(3) were observed.Furthermore,approximately 90%of UHA were observed to be electrically charged,for the first time according to our knowledge.Based on this discovery,we proposed and tested a newmethod to remove UHA by using a simple electrical field.The designed electrical field in this work can efficiently remove 81.4%of UHA.Therefore,applying this electrical field could be an effective method to significantly reduce the health risks by UHA.展开更多
Inhalation of atmospheric PM_(2.5)can induce the generation of excessive reactive oxygen species(ROS)in human alveoli,triggering local and systemic inflammation,which can directly or indirectly result in respiratory a...Inhalation of atmospheric PM_(2.5)can induce the generation of excessive reactive oxygen species(ROS)in human alveoli,triggering local and systemic inflammation,which can directly or indirectly result in respiratory and cardiovascular diseases.In this study,we assessed the oxidative potential(OP)of fresh and O_(3)-aged PM_(2.5)particles from various urban and rural emission sources using the dithiothreitol(DTT)method.Our results revealed variations in the OP of fresh PM_(2.5)among different emission sources,with biomass burning sources exhibiting the highest OP,followed by industrial areas,vehicular emissions,cooking emissions,and suburban areas,respectively.Water-soluble organics and transition metals might potentially exert significant influence on particle OP.O_(3)aging notably decreased the OP of PM_(2.5)particles,possibly due to the oxidation of highly DTT-active components into low redox-active small molecules.Moreover,the evolution of OP in different PM_(2.5)components,including methanol-soluble and insoluble fractions,exhibited distinct responses to O_(3)aging for source-oriented PM_(2.5).Additionally,differences in chemical composition between fresh and aged PM_(2.5)were further elucidated through measurements of component-dependent hygroscopic behaviors and phase transitions.This study systematically delineates variances in the toxic potential of fresh and O_(3)-aged PM_(2.5)from various anthropogenic sources.The findings highlight the intrinsic compositional dependence of particle OP and provide essential insights for assessing the health effects of source-oriented PM_(2.5),as well as for formulating human health protection policies.展开更多
Nitrate renoxification significantly influences atmospheric nitrogen cycling and global OH budgets.Although numerous nitrite acid(HONO)formation pathways from nitrate photolysis have been widely reported,the influence...Nitrate renoxification significantly influences atmospheric nitrogen cycling and global OH budgets.Although numerous nitrite acid(HONO)formation pathways from nitrate photolysis have been widely reported,the influence of various environmental factors and aerosol properties on reactive nitrogen production remains largely unclear.In this work,we employed NaNO_(3)/humic acid(HA)as a model nitrate photosensitization system to investigate the crucial roles of aerosol acidity,organic fraction,and dissolved oxygen in the production of HONO,NO_(2),and NO_(2)^(-).The presence of HA at 10 mg/L resulted in a remarkable increase in HONO production rates by approximately 2–3 times and NO_(2)^(-) concentration by 3–6 times across a pH range of 5.2 to 2.0.Meanwhile,the molar fraction of gaseous HONO in total N(Ⅲ)production increased from4%to 69%as bulk-phase pH decreased from 5.2 to 2.0.The higher organic fraction(i.e.,20 and 50 mg/L HA concentration)instead inhibited HONO and NO_(2) release.The presence of dissolved oxygen was found to be adverse for reactive nitrogen production.This suggests that the HA photosensitizer promoted the secondary conversion of NO_(2) to HONO mainly via reduced ketyl radical intermediates,while superoxide radical formation might exert a negative effect.Our findings provide comprehensive insights into reactive nitrogen production from photosensitized nitrate photolysis mediated by various external and internal factors,potentially accounting for discrepancies between field observations and model simulations.展开更多
We conducted a comprehensive analysis of seasonal and long-term variations in organic carbon(OC),elemental carbon(EC),primary organic carbon(POC),and secondary organic carbon(SOC)among total suspended particles on Hua...We conducted a comprehensive analysis of seasonal and long-term variations in organic carbon(OC),elemental carbon(EC),primary organic carbon(POC),and secondary organic carbon(SOC)among total suspended particles on Huaniao Island,China,from 2011 to 2020.The highest OC and EC concentrations were observed in 2014(OC,4.13μg/m^(3))and 2013(EC,1.21μg/m^(3)),respectively;for both,the lowest concentrations occurred in 2017(OC,1.56μg/m^(3);EC,0.69μg/m^(3)).OC and EC exhibited seasonal variations,such that the highest and lowest values for both occurred in winter and summer,respectively;particularly high concentrations were observed in the winter of 2014 on Huaniao Island.By 2020,winter OC and EC concentrations had decreased by 43%and 36%,whereas autumn OC and EC concentrations increased by 38%and 160%compared with 2014.In terms of carbon components,the proportions of OC4 and EC1 significantly declined,whereas the proportions of OC3 and OC2 increased,during the study period.Higher POC and SOC concentrations were mainly observed during the autumn–winter and winter–spring transition periods.POC was most strongly correlated with OC2,followed by OC4 and EC1.SOC was strongly correlated with OC3,especially in winter.These findings highlight the characteristics of temporal variations in individual carbon components,as well as possible associations with POC and SOC.展开更多
Volatile organic compounds （VOCs） are a kind of important precursors for ozone photochemical formation. In this study, VOCs were measured from November 5th, 2013 to January 6th, 2014 at the Second Jinshan Industrial...Volatile organic compounds （VOCs） are a kind of important precursors for ozone photochemical formation. In this study, VOCs were measured from November 5th, 2013 to January 6th, 2014 at the Second Jinshan Industrial Area, Shanghai, China. The results showed that the measured VOCs were dominated by alkanes （41.8%）, followed by aromatics （20.1%）, alkenes （17.9%）, and halo-hydrocarbons （12.5%）. The daily trend of the VOC concentration showed a bimodal feature due to the rush-hour traffic in the morning and at nightfall. Based on the VOC concentration, a receptor model of Positive Matrix Factorization （PMF） coupled with the information related to VOC sources was applied to identify the major VOC emissions. The result showed five major VOC sources： solvent use and industrial processes were responsible for about 30% of the ambient VOCs, followed by rubber chemical industrial emissions （23%）, refinery and petrochemical industrial emissions （21%）, fuel evaporations （13%） and vehicular emissions （13%）. The contribution of generalized industrial emissions was about 74% and significantly higher than that made by vehicle exhaust. Using a propylene-equivalent method, alkenes displayed the highest concentra-tion, followed by aromatics and alkanes. Based on a maximum incremental reactivity （MIR） method, the average hourly ozone formation potential （OFP） of VOCs is 220.49 ppbv. The most significant source for ozone chemical formation was identified to be rubber chemical industrial emissions, following one by vehicular emission. The data shown herein may provide useful information to develop effective VOC pollution control strategies in industrialized area.展开更多
This paper explores the role of the secondary inorganic aerosol （SIA） species ammonium,NH4＋,nitrate,NO3-,and sulfate,SO24-,during haze and fog events using hourly mass concentrations of PM2.5 measured at a suburban...This paper explores the role of the secondary inorganic aerosol （SIA） species ammonium,NH4＋,nitrate,NO3-,and sulfate,SO24-,during haze and fog events using hourly mass concentrations of PM2.5 measured at a suburban site in Hangzhou,China.A total of 546 samples were collected between 1 April and 8 May 2012.The samples were analyzed and classified as clear,haze or fog depending on visibility and relative humidity （RH）.The contribution of SIA species to PM2.5 mass increased to ～50％ during haze and fog.The mass contribution of nitrate to PM2.5 increased from 11％ during clear to 20％ during haze episodes.Nitrate mass exceeded sulfate mass during haze,while near equal concentrations were observed during fog episodes.The role of RH on the correlation between concentrations of SIA and visibility was examined,with optimal correlation at 60％-70％ RH.The total acidity during clear,haze and fog periods was 42.38,48.38 and 45.51 nmol m-3,respectively,indicating that sulfate,nitrate and chloride were not neutralized by ammonium during any period.The nitrate to sulfate molar ratio,as a function of the ammonium to sulfate molar ratio,indicated that nitrate formation during fog started at a higher ammonium to sulfate molar ratio compared to clear and haze periods.During haze and fog,the nitrate oxidation ratio increased by a factor of 1.6-1.7,while the sulfur oxidation ratio increased by a factor of 1.2-1.5,indicating that both gaseous NO2 and SO2 were involved in the reduced visibility.展开更多
This in vitrostudy aims to evaluate the crystal and surface microstructure of dental enamel after cold-light bleaching treatment. Twelve sound human premolars were cross-split into four specimens, namely, mesio-buccal...This in vitrostudy aims to evaluate the crystal and surface microstructure of dental enamel after cold-light bleaching treatment. Twelve sound human premolars were cross-split into four specimens, namely, mesio-buccal （Group LP）, disto-buccal （Group P）, mesio-lingual （Group NP） and disto-lingual （Group L） specimens. These four groups were treated using the standard cold-light bleaching procedure, a bleaching agent, a peroxide-free bleaching agent and cold-light, respectively. Before and after treatment, all specimens were analyzed by high-resolution, micro-area X-ray diffraction and scanning electron microscopy. Using a spectrometer, tooth color of all specimens was measured before and after treatment. The phase of the enamel crystals was identified as hydroxyapatite and carbonated hydroxyapatite. After treatment, specimens in Groups LP and P showed significantly weaker X-ray diffraction peaks, significant reduction in crystal size and crystallinity, significant increase in L~ but decrease in a＊ and b＊, and obvious alterations in the surface morphology. However, specimens in Groups NP and L did not show any significant changes. The cold-light bleaching treatment leads to demineralization in the enamel surface. The acidic peroxide-containing bleaching agent was the major cause of demineralization, whereas cold-light did not exhibit significant increase or decrease effect on this demineralization.展开更多
Peroxyacetyl nitrate （PAN）, as a major secondary pollutant, has gained increasing worldwide attentions, but relevant studies in China are still quite limited. During winter of 2015 to summer of 2016, the ambient lev...Peroxyacetyl nitrate （PAN）, as a major secondary pollutant, has gained increasing worldwide attentions, but relevant studies in China are still quite limited. During winter of 2015 to summer of 2016, the ambient levels of PAN were measured continuously by an automatic gas chromatograph equipped with an electron capture detector （GC-ECD） analyzer at an urban site in Jinan （China）, with related parameters including concentrations of 03, NO, NO2, PM2.5, HONO, the photolysis rate constant of NO2 and meteorological factors observed concurrently. The mean and maximum values of PAN concentration were （1.89 ± 1.42） and 9.61 ppbv respectively in winter, and （2.54 ± 1.44） and 13.47 ppbv respectively in summer. Unusually high levels of PAN were observed during severe haze episodes in winter, and the formation mechanisms of them were emphatically discussed, Study showed that high levels of PAN in winter were mainly caused by local accumulation and strong photochemical reactions during haze episodes, while mass transport played only a minor role. Accelerated photochemical reactions （compared to winter days without haze） during haze episodes were deduced by the higher concentrations but shorter lifetimes of pAN, which was further supported by the sufficient solar radiation in the photolysis band along with the high concentrations of precursors （NO2, VOCs） and HONO during haze episodes. In addition, significant PAN accumulation during calm weather of haze episodes was verified by meteorological data.展开更多
We report a case of a traveler who visited Uganda for 8 d, and took mefloquine one tablet/week for malaria prophylaxis. After the second dose, he suffered from two episodes of loss of consciousness with seizures, ther...We report a case of a traveler who visited Uganda for 8 d, and took mefloquine one tablet/week for malaria prophylaxis. After the second dose, he suffered from two episodes of loss of consciousness with seizures, therefore mefloquine was discontinued. During the flight back after full recovery, seizures reoccurred while he was on board, he was disembarked in Addis Ababa and then transferred to Nairobi. After repatriation to Italy, he experienced four other similar episodes. The patient was still on full dose anticonvulsant therapy one year and a half after, as any attempt at reduced dose was unsuccessful. Currently, three agents(mefloquine, atovaquone/proguanil, and doxycycline) are recommended for malaria chemoprophylaxis, with similar efficacy but different adverse event profiles, regimens, and prices. Considering that mefloquine is associated with a higher risk of neurologic and psychiatric adverse events than the alternative regimens, we suggest considering mefloquine as a second line choice after atovaquone/progua-nil and doxycycline for short-term travelers.展开更多
PM2.5 aerosols were sampled in urban Chengdu from April 2009 to January 2010, and their chemical compositions were characterized in detail for elements, water soluble inorganic ions, and carbonaceous mat- ter. The ann...PM2.5 aerosols were sampled in urban Chengdu from April 2009 to January 2010, and their chemical compositions were characterized in detail for elements, water soluble inorganic ions, and carbonaceous mat- ter. The annual average of PM2.5 was 165 btg m a, which is generally higher than measurements in other Chinese cities, suggesting serious particulate pollution issues in the city. Water soluble ions contributed 43.5% to the annual total PM2.5 mass, carbonaceous aerosols including elemental carbon and organic car- bon contributed 32.0%, and trace elements contributed 13.8~0. Distinct daily and seasonal variations were observed in the mass concentrations of PM2.5 and its components, reflecting the seasonal variations of dif- ferent anthropogenic and natural sources. Weakly acidic to neutral particles were found for PMz5. Major sources of PM2.u identified from source apportionment analysis included coal combustion, traffic exhaust, biomass burning, soil dust, and construction dust emissions. The low nitrate： sulfate ratio suggested that stationary emissions were more important than vehicle emissions. The reconstructed masses of ammonium sulfate, ammonium nitrate, particulate carbonaceous matter, and fine soil accounted for 79% of the total measured PM2.5 mass; they also accounted for 92% of the total measured particle scattering.展开更多
BACKGROUND： Although cupping remains a popular treatment modality worldwide, its efficacy for most diseases, including hypertension, has not been scientifically evaluated. OBJECTIVE： We aimed to determine the effica...BACKGROUND： Although cupping remains a popular treatment modality worldwide, its efficacy for most diseases, including hypertension, has not been scientifically evaluated. OBJECTIVE： We aimed to determine the efficacy of wet-cupping for high blood pressure, and the incidence of the procedure＇s side effects in the intervention group. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS： This is a randomized controlled trial conducted in the General Practice Department at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, between May 2013 and February 2014. There were two groups （40 participants each）： intervention group undergoing wet-cupping （hijama） in addition to conventional hypertension treatment, and a control group undergoing only conventional hypertension treatment. Three wet-cupping sessions were performed every other day. MAIN OUTCOME MEASURE： The mean systolic and diastolic blood pressures were measured using a validated automatic sphygmomanometer. The follow-up period was 8 weeks. RESULTS： Wet-cupping provided an immediate reduction of systolic blood pressure. After 4 weeks of follow-up, the mean systolic blood pressure in the intervention group was 8.4 mmHg less than in the control group （P = 0.046）. After 8 weeks, there were no significant differences in blood pressures between the intervention and control groups. In this study, wet-cupping did not result in any serious side effects. CONCLUSION： Wet-cupping therapy is effective for reducing systolic blood pressure in hypertensive patients for up to 4 weeks, without serious side effects. Wet-cupping should be considered as a complementary hypertension treatment, and further studies are needed.展开更多
Bismuth-based material has been broadly studied due to their potential applications in various areas,especially used as promising photocatalysts for the removal of persistent organic pollutants(POPs) and several appro...Bismuth-based material has been broadly studied due to their potential applications in various areas,especially used as promising photocatalysts for the removal of persistent organic pollutants(POPs) and several approaches have been adopted to tailor their features.Herein,the bismuth-based photocatalysts(BiOCl,BiPO4,BiOPO4/BiOCl) were synthesized by hydrothermal method and advanced characterization techniques(XRD,SEM,EDS elemental mapping,Raman and UV-vis DRS) were employed to analyze their morphology,crystal structure,and purity of the prepared photocatalysts.These synthesized photocatalysts offered a praiseworthy activity as compared to commercial TiO2(P25) for the degradation of model pollutant perfluorooctanoic acid(PFOA) under 254 nm UV light.It was interesting to observe that all synthesized photocatalysts show significant degradation of PFOA and their photocatalytic activity follows the order:bismuth-based catalysts> TiO2(P25)> without catalyst.Bismuth-based catalysts degraded the PFOA by almost 99.99% within 45 min while this degradation efficiency was 66.05% with TiO2 under the same reaction condition.Our work shows that the bismuth-based photocatalysts are promising in PFOA treatment.展开更多
Converting solar energy into hydrogen and hydrocarbon fuels through photocatalytic H2production and CO2photoreduction is a highly promising approach to address growing demand for clean andrenewable energy resources.Ho...Converting solar energy into hydrogen and hydrocarbon fuels through photocatalytic H2production and CO2photoreduction is a highly promising approach to address growing demand for clean andrenewable energy resources.However,solar‐to‐fuel conversion efficiencies of current photocatalysts are not sufficient to meet commercial requirements.The narrow window of solar energy that can be used has been identified as a key reason behind such low photocatalytic reaction efficiencies.The use of photonic crystals,formed from multiple material components,has been demonstrated to be an effective way of improving light harvesting.Within these nanostructures,the slow‐photon effect,a manifestation of light‐propagation control,considerably enhances the interaction between light and the semiconductor components.This article reviews recent developments in the applications of photonic crystals to photocatalytic H2production and CO2reduction based on slow photons.These advances show great promise for improving light harvesting in solar‐energy conversion technologies.展开更多
Background:Extra-pair copulation behavior has been widely studied among socially monogamous birds.Many species revealed high rates of extra-pair paternity.But few of the studies have been carried out in the Asian popu...Background:Extra-pair copulation behavior has been widely studied among socially monogamous birds.Many species revealed high rates of extra-pair paternity.But few of the studies have been carried out in the Asian population.Methods:From 2012 to 2019,we explored the extra-pair paternity of Marsh Tits(Poecile palustris)in Xianrendong National Nature Reserve,Liaoning Province,China.During the study,adult Marsh Tits were captured with mist nets and parental birds,with nest-box traps.Blood samples were taken from the brachial vein.Parentage analyses were carried out using nine highly variable microsatellite loci through Cervus 3.0 software and maximum likelihood approach.Results:Forty-nine offspring(15.08%)from 20 nests(45.45%)were the results of extra-pair fertilization out of a total of 325 offspring in 44 nests.The average extra-pair offspring ratio was 33.54%,with a set varying from 11.11 to 71.43%.Nine extra-pair fathers had been successfully identified,four of whom were the close neighbors of the focus nest while the nests of the remaining five were relatively far.No significant difference was found in the genetic similarity between the social and extra-pair mates of the female,nor in the heterozygosis among the maternal half-siblings.Conclusions:In general,our study proved that the extra-pair paternity in Marsh Tits and its extra-pair mating is independent of the genetic compatibility hypothesis.This complements the understudied bird's extra-pair paternity in Asian area and contributes to the comprehensive insight of birds'extra-pair paternity behaviors.展开更多
Sulfate aerosol contributes to particulate matter pollution and plays a key role in aerosol radiative forcing,impacting human health and climate change.Atmospheric models tend to substantially underestimate sulfate co...Sulfate aerosol contributes to particulate matter pollution and plays a key role in aerosol radiative forcing,impacting human health and climate change.Atmospheric models tend to substantially underestimate sulfate concentrations during haze episodes,indicating that there are still missing mechanisms not considered by the models.Despite recent good progress in understanding the missing sulfate sources,knowledge on different sulfate formation pathways during polluted periods still involves large uncertainties and the dominant mechanism is under heated debate,calling for more field,laboratory,and modeling work.Here,we review the traditional sulfate formation mechanisms in cloud water and also discuss the potential factors affecting multiphase S(Ⅳ)oxidation.Then recent progress in multiphase S(Ⅳ)oxidation mechanisms is summarized.Sulfate formation rates by different prevailing oxidation pathways under typical winter-haze conditions are also calculated and compared.Based on the literature reviewed,we put forward control of the atmospheric oxidation capacity as a means to abate sulfate aerosol pollution.Finally,we conclude with a concise set of research priorities for improving our understanding of sulfate formation mechanisms during polluted periods.展开更多
To investigate formation mechanisms of secondary organic carbon（SOC） in Eastern China,measurements were conducted in an urban site in Shanghai in the summer of 2015. A period of high O3 concentrations（daily peak 〉...To investigate formation mechanisms of secondary organic carbon（SOC） in Eastern China,measurements were conducted in an urban site in Shanghai in the summer of 2015. A period of high O3 concentrations（daily peak 〉 120 ppb） was observed, during which daily maximum SOC concentrations exceeding 9.0 μg/（C·m^3）. Diurnal variations of SOC concentration and SOC/organic carbon（OC） ratio exhibited both daytime and nighttime peaks. The SOC concentrations correlated well with Ox（= O3＋ NO2） and relative humidity in the daytime and nighttime, respectively, suggesting that secondary organic aerosol formation in Shanghai is driven by both photochemical production and aqueous phase reactions. Single particle mass spectrometry was used to examine the formation pathways of SOC. Along with the daytime increase of SOC, the number fraction of elemental carbon（EC） particles coated with OC quickly increased from 38.1% to 61.9% in the size range of 250–2000 nm, which was likely due to gas-to-particle partitioning of photochemically generated semi-volatile organic compounds onto EC particles. In the nighttime, particles rich in OC components were highly hygroscopic, and number fraction of these particles correlated well with relative humidity and SOC/OC nocturnal peaks. Meanwhile, as an aqueous-phase SOC tracer, particles that contained oxalate-Fe（III） complex also peaked at night. These observations suggested that aqueous-phase processes had an important contribution to the SOC nighttime formation. The influence of aerosol acidity on SOC formation was studied by both bulk and single particle level measurements, suggesting that the aqueous-phase formation of SOC was enhanced by particle acidity.展开更多
Tunnel displays a typical semi-closed environment, and multitudes of the pollutants tend to accumulate. The samples of gaseous pollutants and particulate matter （PM） were collected from the Xiangyin tunnel at Shangh...Tunnel displays a typical semi-closed environment, and multitudes of the pollutants tend to accumulate. The samples of gaseous pollutants and particulate matter （PM） were collected from the Xiangyin tunnel at Shanghai to investigate the characteristics of the pollutant emissions. The results indicated that both gaseous pollutants and PM exhibited much higher concentrations during the rush hours in the morning and at night due to vehicle emission. Two peaks of the PM concentration were observed in the scope of 0.7-1.1 and 3.3-4.7 μm, accounting for 14.6% and 20.3% of the total concentrations, respectively. Organic matter （OM）, EC, and many water-soluble ions were markedly higher at the rush hours in the morning than those at night, implicating comprehensive effects of vehicle types and traffic volume. The particle number concentrations exhibited two peaks at Aitken mode （25 nm and 100 rim） and accumulation mode （600 nm）, while the particle volume concentration displayed high values at the accumulation mode （100-500 nm） and coarse mode （2.5-4.0 μm）. The peak around 100 nm was detected in the morning rush hours, but it diminished with the decrease of the traffic volume. Individual-particle analysis revealed that main particles in the tunnel were Fe-rich particles, K-rich particles, mineral particles, Ca-S rich particles and A1-Si particles. The particles collected at the rush hours displayed marked different morphologies, element concentrations and particle sizes compared to the ones collected at the non-rush period. The data presented herein could shed a light on the feature of vehicle emissions.展开更多
Cadmium(Cd) mainly derived from anthropogenic emissions can be transported through atmospheric pathway to marine ecosystem,affecting the phytoplankton community and primary productivity.In this study,we identified the...Cadmium(Cd) mainly derived from anthropogenic emissions can be transported through atmospheric pathway to marine ecosystem,affecting the phytoplankton community and primary productivity.In this study,we identified the toxicity threshold of Cd for phytoplankton under seawater conditions of the coastal East China Sea(ECS) through both laboratory and in situ mesocosm incubation experiments.The mesocosm experiment showed that Cd in low concentration(0.003 μg per μg chl a) was conducive to the growth of natural community and increased chl a productivity.In high concentration(0.03 μg per μg chl a) Cd acted as an inhibiting factor which decreased the total chl a productivity.The diatom community was found to be more sensitive to Cd toxicity than dinoflagellate,as the low concentration Cd showed toxicity to diatom but enhanced dinoflagellate growth.We noticed that the soluble Cd estimated from atmosphere deposition to the coastal ECS was below the toxicity threshold and the Cd deposition might promote phytoplankton growth in this region.In our laboratory experiments,adding Cd,similar to aerosol deposition,stimulated the growth of both dominant algal species Prorocentrum donghaiense Lu(dinoflagellate) and Skeletonema costatum(diatom).Adding Cd on a higher level inhibited the growth of both the species,but Skeletonema costatum seemed obviously more sensitive to toxicity.This indicates the potential impact of atmospheric deposition Cd on phytoplankton community succession in the ECS.展开更多
基金supported by the National Natural Science Foundation of China (Nos.42077193 and 21976034)the National Key R&D Program (Nos.2022YFC3702600 and 2022YFC3702601)the Shanghai Natural Science Foundation (23ZR1479700).
文摘Ultrasonic humidifiers are commonly used in households to maintain indoor humidity and generate a large number of droplets or spray aerosols.However,there have been various health concerns associated with humidifier use,largely due to aerosols generated during operation.Here,we investigated the size distribution,chemical composition,and charged fraction of aerosol particles emitted from commercial ultrasonic humidifiers.Heavy metals in water used for humidifiers were found to be highly enriched in the ultrasonic humidifier aerosols(UHA),with the enrichment factors ranging from 102 to 107.This enrichment may pose health concerns for the building occupants,as UHA concentrations of up to 106 particles/cm^(3) or 3 mg/m^(3) were observed.Furthermore,approximately 90%of UHA were observed to be electrically charged,for the first time according to our knowledge.Based on this discovery,we proposed and tested a newmethod to remove UHA by using a simple electrical field.The designed electrical field in this work can efficiently remove 81.4%of UHA.Therefore,applying this electrical field could be an effective method to significantly reduce the health risks by UHA.
基金supported by the National Natural Science Foundation of China(No.42305109)Quzhou Municipal Science and Technology Bureau(No.2023K222).
文摘Inhalation of atmospheric PM_(2.5)can induce the generation of excessive reactive oxygen species(ROS)in human alveoli,triggering local and systemic inflammation,which can directly or indirectly result in respiratory and cardiovascular diseases.In this study,we assessed the oxidative potential(OP)of fresh and O_(3)-aged PM_(2.5)particles from various urban and rural emission sources using the dithiothreitol(DTT)method.Our results revealed variations in the OP of fresh PM_(2.5)among different emission sources,with biomass burning sources exhibiting the highest OP,followed by industrial areas,vehicular emissions,cooking emissions,and suburban areas,respectively.Water-soluble organics and transition metals might potentially exert significant influence on particle OP.O_(3)aging notably decreased the OP of PM_(2.5)particles,possibly due to the oxidation of highly DTT-active components into low redox-active small molecules.Moreover,the evolution of OP in different PM_(2.5)components,including methanol-soluble and insoluble fractions,exhibited distinct responses to O_(3)aging for source-oriented PM_(2.5).Additionally,differences in chemical composition between fresh and aged PM_(2.5)were further elucidated through measurements of component-dependent hygroscopic behaviors and phase transitions.This study systematically delineates variances in the toxic potential of fresh and O_(3)-aged PM_(2.5)from various anthropogenic sources.The findings highlight the intrinsic compositional dependence of particle OP and provide essential insights for assessing the health effects of source-oriented PM_(2.5),as well as for formulating human health protection policies.
基金supported by the National Key R&D Program of China(No.2022YFC3701102)the National Natural Science Foundation of China(Nos.22376029,22176038,91744205 and 21777025)the Natural Science Foundation of Shanghai City(No.22ZR1404700).
文摘Nitrate renoxification significantly influences atmospheric nitrogen cycling and global OH budgets.Although numerous nitrite acid(HONO)formation pathways from nitrate photolysis have been widely reported,the influence of various environmental factors and aerosol properties on reactive nitrogen production remains largely unclear.In this work,we employed NaNO_(3)/humic acid(HA)as a model nitrate photosensitization system to investigate the crucial roles of aerosol acidity,organic fraction,and dissolved oxygen in the production of HONO,NO_(2),and NO_(2)^(-).The presence of HA at 10 mg/L resulted in a remarkable increase in HONO production rates by approximately 2–3 times and NO_(2)^(-) concentration by 3–6 times across a pH range of 5.2 to 2.0.Meanwhile,the molar fraction of gaseous HONO in total N(Ⅲ)production increased from4%to 69%as bulk-phase pH decreased from 5.2 to 2.0.The higher organic fraction(i.e.,20 and 50 mg/L HA concentration)instead inhibited HONO and NO_(2) release.The presence of dissolved oxygen was found to be adverse for reactive nitrogen production.This suggests that the HA photosensitizer promoted the secondary conversion of NO_(2) to HONO mainly via reduced ketyl radical intermediates,while superoxide radical formation might exert a negative effect.Our findings provide comprehensive insights into reactive nitrogen production from photosensitized nitrate photolysis mediated by various external and internal factors,potentially accounting for discrepancies between field observations and model simulations.
基金supported by the National Natural Science Foundation of China(Nos.42076205 and 42376195).
文摘We conducted a comprehensive analysis of seasonal and long-term variations in organic carbon(OC),elemental carbon(EC),primary organic carbon(POC),and secondary organic carbon(SOC)among total suspended particles on Huaniao Island,China,from 2011 to 2020.The highest OC and EC concentrations were observed in 2014(OC,4.13μg/m^(3))and 2013(EC,1.21μg/m^(3)),respectively;for both,the lowest concentrations occurred in 2017(OC,1.56μg/m^(3);EC,0.69μg/m^(3)).OC and EC exhibited seasonal variations,such that the highest and lowest values for both occurred in winter and summer,respectively;particularly high concentrations were observed in the winter of 2014 on Huaniao Island.By 2020,winter OC and EC concentrations had decreased by 43%and 36%,whereas autumn OC and EC concentrations increased by 38%and 160%compared with 2014.In terms of carbon components,the proportions of OC4 and EC1 significantly declined,whereas the proportions of OC3 and OC2 increased,during the study period.Higher POC and SOC concentrations were mainly observed during the autumn–winter and winter–spring transition periods.POC was most strongly correlated with OC2,followed by OC4 and EC1.SOC was strongly correlated with OC3,especially in winter.These findings highlight the characteristics of temporal variations in individual carbon components,as well as possible associations with POC and SOC.
基金supported by the National Key R&D Program of China(No.2016YFC0202700)the Ministry of Science and Technology of the People's Republic of China(No.2016YFE0112200)+2 种基金the National Natural Science Foundation of China(Nos.21777025,21577022,21190053,40975074)the Marie Sklodowska-Curie Actions(690958-MARSU-RISE-2015)the international cooperation project of Shanghai municipal government(15520711200)
文摘Volatile organic compounds （VOCs） are a kind of important precursors for ozone photochemical formation. In this study, VOCs were measured from November 5th, 2013 to January 6th, 2014 at the Second Jinshan Industrial Area, Shanghai, China. The results showed that the measured VOCs were dominated by alkanes （41.8%）, followed by aromatics （20.1%）, alkenes （17.9%）, and halo-hydrocarbons （12.5%）. The daily trend of the VOC concentration showed a bimodal feature due to the rush-hour traffic in the morning and at nightfall. Based on the VOC concentration, a receptor model of Positive Matrix Factorization （PMF） coupled with the information related to VOC sources was applied to identify the major VOC emissions. The result showed five major VOC sources： solvent use and industrial processes were responsible for about 30% of the ambient VOCs, followed by rubber chemical industrial emissions （23%）, refinery and petrochemical industrial emissions （21%）, fuel evaporations （13%） and vehicular emissions （13%）. The contribution of generalized industrial emissions was about 74% and significantly higher than that made by vehicle exhaust. Using a propylene-equivalent method, alkenes displayed the highest concentra-tion, followed by aromatics and alkanes. Based on a maximum incremental reactivity （MIR） method, the average hourly ozone formation potential （OFP） of VOCs is 220.49 ppbv. The most significant source for ozone chemical formation was identified to be rubber chemical industrial emissions, following one by vehicular emission. The data shown herein may provide useful information to develop effective VOC pollution control strategies in industrialized area.
基金supported by the National Natural Science Foundation of China (Grant Nos. 21190053 and 21177025)the Shanghai Science and Technology Commission of Shanghai Municipality (Grant Nos. 12DJ1400100 and 13XD 1400700)the Priority Fields for Ph.D. Programs Foundation of the Ministry of Education of China (Grant No.20110071130003)
文摘This paper explores the role of the secondary inorganic aerosol （SIA） species ammonium,NH4＋,nitrate,NO3-,and sulfate,SO24-,during haze and fog events using hourly mass concentrations of PM2.5 measured at a suburban site in Hangzhou,China.A total of 546 samples were collected between 1 April and 8 May 2012.The samples were analyzed and classified as clear,haze or fog depending on visibility and relative humidity （RH）.The contribution of SIA species to PM2.5 mass increased to ～50％ during haze and fog.The mass contribution of nitrate to PM2.5 increased from 11％ during clear to 20％ during haze episodes.Nitrate mass exceeded sulfate mass during haze,while near equal concentrations were observed during fog episodes.The role of RH on the correlation between concentrations of SIA and visibility was examined,with optimal correlation at 60％-70％ RH.The total acidity during clear,haze and fog periods was 42.38,48.38 and 45.51 nmol m-3,respectively,indicating that sulfate,nitrate and chloride were not neutralized by ammonium during any period.The nitrate to sulfate molar ratio,as a function of the ammonium to sulfate molar ratio,indicated that nitrate formation during fog started at a higher ammonium to sulfate molar ratio compared to clear and haze periods.During haze and fog,the nitrate oxidation ratio increased by a factor of 1.6-1.7,while the sulfur oxidation ratio increased by a factor of 1.2-1.5,indicating that both gaseous NO2 and SO2 were involved in the reduced visibility.
文摘This in vitrostudy aims to evaluate the crystal and surface microstructure of dental enamel after cold-light bleaching treatment. Twelve sound human premolars were cross-split into four specimens, namely, mesio-buccal （Group LP）, disto-buccal （Group P）, mesio-lingual （Group NP） and disto-lingual （Group L） specimens. These four groups were treated using the standard cold-light bleaching procedure, a bleaching agent, a peroxide-free bleaching agent and cold-light, respectively. Before and after treatment, all specimens were analyzed by high-resolution, micro-area X-ray diffraction and scanning electron microscopy. Using a spectrometer, tooth color of all specimens was measured before and after treatment. The phase of the enamel crystals was identified as hydroxyapatite and carbonated hydroxyapatite. After treatment, specimens in Groups LP and P showed significantly weaker X-ray diffraction peaks, significant reduction in crystal size and crystallinity, significant increase in L~ but decrease in a＊ and b＊, and obvious alterations in the surface morphology. However, specimens in Groups NP and L did not show any significant changes. The cold-light bleaching treatment leads to demineralization in the enamel surface. The acidic peroxide-containing bleaching agent was the major cause of demineralization, whereas cold-light did not exhibit significant increase or decrease effect on this demineralization.
基金supported by the National Key R&D Program of China(No.2016YFC0202700)the National Natural Science Foundation of China(Nos.41375126,21527814,91743202)the H2020 Marie Sklodowska-Curie Actions(No.H2020-MSCARISE-2015-690958)
文摘Peroxyacetyl nitrate （PAN）, as a major secondary pollutant, has gained increasing worldwide attentions, but relevant studies in China are still quite limited. During winter of 2015 to summer of 2016, the ambient levels of PAN were measured continuously by an automatic gas chromatograph equipped with an electron capture detector （GC-ECD） analyzer at an urban site in Jinan （China）, with related parameters including concentrations of 03, NO, NO2, PM2.5, HONO, the photolysis rate constant of NO2 and meteorological factors observed concurrently. The mean and maximum values of PAN concentration were （1.89 ± 1.42） and 9.61 ppbv respectively in winter, and （2.54 ± 1.44） and 13.47 ppbv respectively in summer. Unusually high levels of PAN were observed during severe haze episodes in winter, and the formation mechanisms of them were emphatically discussed, Study showed that high levels of PAN in winter were mainly caused by local accumulation and strong photochemical reactions during haze episodes, while mass transport played only a minor role. Accelerated photochemical reactions （compared to winter days without haze） during haze episodes were deduced by the higher concentrations but shorter lifetimes of pAN, which was further supported by the sufficient solar radiation in the photolysis band along with the high concentrations of precursors （NO2, VOCs） and HONO during haze episodes. In addition, significant PAN accumulation during calm weather of haze episodes was verified by meteorological data.
文摘We report a case of a traveler who visited Uganda for 8 d, and took mefloquine one tablet/week for malaria prophylaxis. After the second dose, he suffered from two episodes of loss of consciousness with seizures, therefore mefloquine was discontinued. During the flight back after full recovery, seizures reoccurred while he was on board, he was disembarked in Addis Ababa and then transferred to Nairobi. After repatriation to Italy, he experienced four other similar episodes. The patient was still on full dose anticonvulsant therapy one year and a half after, as any attempt at reduced dose was unsuccessful. Currently, three agents(mefloquine, atovaquone/proguanil, and doxycycline) are recommended for malaria chemoprophylaxis, with similar efficacy but different adverse event profiles, regimens, and prices. Considering that mefloquine is associated with a higher risk of neurologic and psychiatric adverse events than the alternative regimens, we suggest considering mefloquine as a second line choice after atovaquone/progua-nil and doxycycline for short-term travelers.
基金supported by the Special Scientific Research Funds for Environment Protection Commonweal Section of China (Grant Nos. 201009001)the National Basic Research Program of China (Grant No. 2010CB428503)+4 种基金the Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. IAP09320)the National Natural Science Foundation of China (Grant Nos. 41075096 and 40975076)the Research and Development Special Fund for Public Welfare Industry (Meteorology) of the China Meteorological Administration (Grant No. GYHY201006047)the Ministry of Science and Technology of China (Grant No. 2010DFA22770)the Innovation Method Fund of China (Grant No. 2008IM020500)
文摘PM2.5 aerosols were sampled in urban Chengdu from April 2009 to January 2010, and their chemical compositions were characterized in detail for elements, water soluble inorganic ions, and carbonaceous mat- ter. The annual average of PM2.5 was 165 btg m a, which is generally higher than measurements in other Chinese cities, suggesting serious particulate pollution issues in the city. Water soluble ions contributed 43.5% to the annual total PM2.5 mass, carbonaceous aerosols including elemental carbon and organic car- bon contributed 32.0%, and trace elements contributed 13.8~0. Distinct daily and seasonal variations were observed in the mass concentrations of PM2.5 and its components, reflecting the seasonal variations of dif- ferent anthropogenic and natural sources. Weakly acidic to neutral particles were found for PMz5. Major sources of PM2.u identified from source apportionment analysis included coal combustion, traffic exhaust, biomass burning, soil dust, and construction dust emissions. The low nitrate： sulfate ratio suggested that stationary emissions were more important than vehicle emissions. The reconstructed masses of ammonium sulfate, ammonium nitrate, particulate carbonaceous matter, and fine soil accounted for 79% of the total measured PM2.5 mass; they also accounted for 92% of the total measured particle scattering.
基金funded by King Abdulaziz University(Jeddah,Saudi Arabia)Kashef Diagnostics Factory(Jeddah,Saudi Arabia)
文摘BACKGROUND： Although cupping remains a popular treatment modality worldwide, its efficacy for most diseases, including hypertension, has not been scientifically evaluated. OBJECTIVE： We aimed to determine the efficacy of wet-cupping for high blood pressure, and the incidence of the procedure＇s side effects in the intervention group. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS： This is a randomized controlled trial conducted in the General Practice Department at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, between May 2013 and February 2014. There were two groups （40 participants each）： intervention group undergoing wet-cupping （hijama） in addition to conventional hypertension treatment, and a control group undergoing only conventional hypertension treatment. Three wet-cupping sessions were performed every other day. MAIN OUTCOME MEASURE： The mean systolic and diastolic blood pressures were measured using a validated automatic sphygmomanometer. The follow-up period was 8 weeks. RESULTS： Wet-cupping provided an immediate reduction of systolic blood pressure. After 4 weeks of follow-up, the mean systolic blood pressure in the intervention group was 8.4 mmHg less than in the control group （P = 0.046）. After 8 weeks, there were no significant differences in blood pressures between the intervention and control groups. In this study, wet-cupping did not result in any serious side effects. CONCLUSION： Wet-cupping therapy is effective for reducing systolic blood pressure in hypertensive patients for up to 4 weeks, without serious side effects. Wet-cupping should be considered as a complementary hypertension treatment, and further studies are needed.
基金financial support from Ministry of Science and Technology of the People’s Republic of China (Nos.2016YFE0112200 and 2016YFC0202700)National Natural Science Foundation of China (Nos.21507011,21677037 and 21607027)Natural Science Foundation of Shanghai (Nos. 19ZR1471200,17ZR1440200)
文摘Bismuth-based material has been broadly studied due to their potential applications in various areas,especially used as promising photocatalysts for the removal of persistent organic pollutants(POPs) and several approaches have been adopted to tailor their features.Herein,the bismuth-based photocatalysts(BiOCl,BiPO4,BiOPO4/BiOCl) were synthesized by hydrothermal method and advanced characterization techniques(XRD,SEM,EDS elemental mapping,Raman and UV-vis DRS) were employed to analyze their morphology,crystal structure,and purity of the prepared photocatalysts.These synthesized photocatalysts offered a praiseworthy activity as compared to commercial TiO2(P25) for the degradation of model pollutant perfluorooctanoic acid(PFOA) under 254 nm UV light.It was interesting to observe that all synthesized photocatalysts show significant degradation of PFOA and their photocatalytic activity follows the order:bismuth-based catalysts> TiO2(P25)> without catalyst.Bismuth-based catalysts degraded the PFOA by almost 99.99% within 45 min while this degradation efficiency was 66.05% with TiO2 under the same reaction condition.Our work shows that the bismuth-based photocatalysts are promising in PFOA treatment.
文摘Converting solar energy into hydrogen and hydrocarbon fuels through photocatalytic H2production and CO2photoreduction is a highly promising approach to address growing demand for clean andrenewable energy resources.However,solar‐to‐fuel conversion efficiencies of current photocatalysts are not sufficient to meet commercial requirements.The narrow window of solar energy that can be used has been identified as a key reason behind such low photocatalytic reaction efficiencies.The use of photonic crystals,formed from multiple material components,has been demonstrated to be an effective way of improving light harvesting.Within these nanostructures,the slow‐photon effect,a manifestation of light‐propagation control,considerably enhances the interaction between light and the semiconductor components.This article reviews recent developments in the applications of photonic crystals to photocatalytic H2production and CO2reduction based on slow photons.These advances show great promise for improving light harvesting in solar‐energy conversion technologies.
基金supported by the National Natural Science Foundation of China(Grant No.31872231)to DWthe Youth Foundation of Liaoning University(Grant No.A251901012)to JW。
文摘Background:Extra-pair copulation behavior has been widely studied among socially monogamous birds.Many species revealed high rates of extra-pair paternity.But few of the studies have been carried out in the Asian population.Methods:From 2012 to 2019,we explored the extra-pair paternity of Marsh Tits(Poecile palustris)in Xianrendong National Nature Reserve,Liaoning Province,China.During the study,adult Marsh Tits were captured with mist nets and parental birds,with nest-box traps.Blood samples were taken from the brachial vein.Parentage analyses were carried out using nine highly variable microsatellite loci through Cervus 3.0 software and maximum likelihood approach.Results:Forty-nine offspring(15.08%)from 20 nests(45.45%)were the results of extra-pair fertilization out of a total of 325 offspring in 44 nests.The average extra-pair offspring ratio was 33.54%,with a set varying from 11.11 to 71.43%.Nine extra-pair fathers had been successfully identified,four of whom were the close neighbors of the focus nest while the nests of the remaining five were relatively far.No significant difference was found in the genetic similarity between the social and extra-pair mates of the female,nor in the heterozygosis among the maternal half-siblings.Conclusions:In general,our study proved that the extra-pair paternity in Marsh Tits and its extra-pair mating is independent of the genetic compatibility hypothesis.This complements the understudied bird's extra-pair paternity in Asian area and contributes to the comprehensive insight of birds'extra-pair paternity behaviors.
基金supported by the National Key Research and Development Program of China(No.2019YFC0214801)the China Postdoctoral Science Foundation(Nos.2021M700214 and 2022T150011)。
文摘Sulfate aerosol contributes to particulate matter pollution and plays a key role in aerosol radiative forcing,impacting human health and climate change.Atmospheric models tend to substantially underestimate sulfate concentrations during haze episodes,indicating that there are still missing mechanisms not considered by the models.Despite recent good progress in understanding the missing sulfate sources,knowledge on different sulfate formation pathways during polluted periods still involves large uncertainties and the dominant mechanism is under heated debate,calling for more field,laboratory,and modeling work.Here,we review the traditional sulfate formation mechanisms in cloud water and also discuss the potential factors affecting multiphase S(Ⅳ)oxidation.Then recent progress in multiphase S(Ⅳ)oxidation mechanisms is summarized.Sulfate formation rates by different prevailing oxidation pathways under typical winter-haze conditions are also calculated and compared.Based on the literature reviewed,we put forward control of the atmospheric oxidation capacity as a means to abate sulfate aerosol pollution.Finally,we conclude with a concise set of research priorities for improving our understanding of sulfate formation mechanisms during polluted periods.
基金supported by the National Natural Science Foundation of China(Nos.91544224,21507010,41775150)the Ministry of Science&Technology of China(No.2012YQ220113-4)the Changjiang Scholars program of the Chinese Ministry of Education
文摘To investigate formation mechanisms of secondary organic carbon（SOC） in Eastern China,measurements were conducted in an urban site in Shanghai in the summer of 2015. A period of high O3 concentrations（daily peak 〉 120 ppb） was observed, during which daily maximum SOC concentrations exceeding 9.0 μg/（C·m^3）. Diurnal variations of SOC concentration and SOC/organic carbon（OC） ratio exhibited both daytime and nighttime peaks. The SOC concentrations correlated well with Ox（= O3＋ NO2） and relative humidity in the daytime and nighttime, respectively, suggesting that secondary organic aerosol formation in Shanghai is driven by both photochemical production and aqueous phase reactions. Single particle mass spectrometry was used to examine the formation pathways of SOC. Along with the daytime increase of SOC, the number fraction of elemental carbon（EC） particles coated with OC quickly increased from 38.1% to 61.9% in the size range of 250–2000 nm, which was likely due to gas-to-particle partitioning of photochemically generated semi-volatile organic compounds onto EC particles. In the nighttime, particles rich in OC components were highly hygroscopic, and number fraction of these particles correlated well with relative humidity and SOC/OC nocturnal peaks. Meanwhile, as an aqueous-phase SOC tracer, particles that contained oxalate-Fe（III） complex also peaked at night. These observations suggested that aqueous-phase processes had an important contribution to the SOC nighttime formation. The influence of aerosol acidity on SOC formation was studied by both bulk and single particle level measurements, suggesting that the aqueous-phase formation of SOC was enhanced by particle acidity.
基金supported by the National Key R&D Program of China(2016YFC0202700)Ministry of Science and Technology of China(2016YFE0112200)+2 种基金National Natural Science Foundation of China(Nos.21777025,21577022,21190053,40975074)the Marie Sklodowska-Curie Actions(690958-MARSU-RISE2015)the International Cooperation project of Shanghai municipal government(15520711200)
文摘Tunnel displays a typical semi-closed environment, and multitudes of the pollutants tend to accumulate. The samples of gaseous pollutants and particulate matter （PM） were collected from the Xiangyin tunnel at Shanghai to investigate the characteristics of the pollutant emissions. The results indicated that both gaseous pollutants and PM exhibited much higher concentrations during the rush hours in the morning and at night due to vehicle emission. Two peaks of the PM concentration were observed in the scope of 0.7-1.1 and 3.3-4.7 μm, accounting for 14.6% and 20.3% of the total concentrations, respectively. Organic matter （OM）, EC, and many water-soluble ions were markedly higher at the rush hours in the morning than those at night, implicating comprehensive effects of vehicle types and traffic volume. The particle number concentrations exhibited two peaks at Aitken mode （25 nm and 100 rim） and accumulation mode （600 nm）, while the particle volume concentration displayed high values at the accumulation mode （100-500 nm） and coarse mode （2.5-4.0 μm）. The peak around 100 nm was detected in the morning rush hours, but it diminished with the decrease of the traffic volume. Individual-particle analysis revealed that main particles in the tunnel were Fe-rich particles, K-rich particles, mineral particles, Ca-S rich particles and A1-Si particles. The particles collected at the rush hours displayed marked different morphologies, element concentrations and particle sizes compared to the ones collected at the non-rush period. The data presented herein could shed a light on the feature of vehicle emissions.
基金sponsored by the National Natural Science Foundation of China (41375141)National Basic Research Program of China (2014CB953700)SRF for ROCS,SEM,and Shanghai Science and Technology Committee (12DJ1400102)
文摘Cadmium(Cd) mainly derived from anthropogenic emissions can be transported through atmospheric pathway to marine ecosystem,affecting the phytoplankton community and primary productivity.In this study,we identified the toxicity threshold of Cd for phytoplankton under seawater conditions of the coastal East China Sea(ECS) through both laboratory and in situ mesocosm incubation experiments.The mesocosm experiment showed that Cd in low concentration(0.003 μg per μg chl a) was conducive to the growth of natural community and increased chl a productivity.In high concentration(0.03 μg per μg chl a) Cd acted as an inhibiting factor which decreased the total chl a productivity.The diatom community was found to be more sensitive to Cd toxicity than dinoflagellate,as the low concentration Cd showed toxicity to diatom but enhanced dinoflagellate growth.We noticed that the soluble Cd estimated from atmosphere deposition to the coastal ECS was below the toxicity threshold and the Cd deposition might promote phytoplankton growth in this region.In our laboratory experiments,adding Cd,similar to aerosol deposition,stimulated the growth of both dominant algal species Prorocentrum donghaiense Lu(dinoflagellate) and Skeletonema costatum(diatom).Adding Cd on a higher level inhibited the growth of both the species,but Skeletonema costatum seemed obviously more sensitive to toxicity.This indicates the potential impact of atmospheric deposition Cd on phytoplankton community succession in the ECS.
