With the continuous control of anthropogenic emissions,China’s air quality has improved significantly in recent years.Given this background,research on how the short-term exposure risks caused by air pollution in Chi...With the continuous control of anthropogenic emissions,China’s air quality has improved significantly in recent years.Given this background,research on how the short-term exposure risks caused by air pollution in China have changed is insufficient.This study utilized hourly concentration data from ground observation stations and the official air quality guidelines of the Ministry of Ecology and Environment of China and the World Health Organization as standards to systematically investigate the spatiotemporal characteristics and short-term exposure risks of air pollution in China from 2015 to 2022.The results indicate that various atmospheric pollutants except for ozone showed a decreasing trend yearly.Nationwide,both single pollutant air pollution days(SAPDs)and multiple pollutant air pollution days(MAPDs)showed varying degrees of reduction within 15 and 25 days,respectively.SAPD was dominated mainly by excessive PM_(2.5)and PM_(10)pollutants,while MAPD was dominated mainly by excessive pollutant combinations,including PM_(2.5)+PM_(10),CO+PM_(2.5)+PM_(10),and SO_(2)+PM_(2.5)+PM_(10).As the concentration of atmospheric pollutants decreased,the total excess risk(ER)decreased yearly from 2015 to 2022,but there were significant regional differences.Now,the ER is less than 0.25%in southern China,in the range of 0.25%-0.5%in the North China Plain and some cities in the northeast,and higher than 1%in the northwest.Particulate matter is currently the primary pollutant posing short-term exposure risk in China,especially due to the impact of sandstorm weather.This study indicates that China’s atmospheric cleaning action is significantly beneficial for reducing health risks.展开更多
Fine particulate matter(particulate matter with a diameter of 2.5μm or less;PM2.5)causes millions of premature deaths globally1,but not all particles are equally harmful2-4.Current air-pollution control strategies,pr...Fine particulate matter(particulate matter with a diameter of 2.5μm or less;PM2.5)causes millions of premature deaths globally1,but not all particles are equally harmful2-4.Current air-pollution control strategies,prioritizing PM2.5 mass reduction,have provided considerable health benefits but further refinements based on differences in the toxicity of various emission sources may provide greater benefits5-7.Here we integrated field measurements with air-quality modelling to assess the unequal toxicities of PM2.5 from various anthropogenic sources.展开更多
A hydrodynamic model is used to study Kelvin-Helmholtz(KH)instability of the interface between two particle-laden inviscid fluids moving with two different uniform mean velocities.Explicit eigen-equation is derived to...A hydrodynamic model is used to study Kelvin-Helmholtz(KH)instability of the interface between two particle-laden inviscid fluids moving with two different uniform mean velocities.Explicit eigen-equation is derived to study the effect of suspended particles on the growth rate of KH instability.For dusty gases with negligible volume fraction of heavy particles and small particle-to-fluid mass ratio,the real and imaginary parts of leading-order asymptotic expression derived by the present model for the growth rate are shown to be identical to the earlier results derived by the classical Saffman model established for dusty gases.Beyond the known results,explicit leading-order asymptotic expressions for the effect of suspended particles on the growth rate are derived for several typical cases of basic interest.It is shown that the suspended particles can decrease or increase the growth rate of KH instability depending on the Stokes numbers of the particles and whether the particles are heavier or lighter than the clean fluid.Compared to the mass density of the clean fluid,our results based on leading-order asymptotic solutions show that heavier particles and lighter particles have opposite effects on the growth rate of KH instability,while the effect of neutrally buoyant particles on the growth rate of KH instability is negligible.展开更多
A long-term(2007-2016) particulate matter dataset measured at multiple sites in Chengdu,an expanding megacity in southwest China, was analyzed. The trends of particulate chemical compositions and source apportionment ...A long-term(2007-2016) particulate matter dataset measured at multiple sites in Chengdu,an expanding megacity in southwest China, was analyzed. The trends of particulate chemical compositions and source apportionment were used to evaluate and review the effectiveness of source-specific control policies and measures in Atmospheric Pollution Prevention and Control Action Plan(APPCAP). The concentration of particulate matter decreased significantly, and most aerosol components changed synchronously with particulate matter. The results of advanced three-way factor analysis model suggested that six sources were resolved at three sites: coal combustion, vehicle, crustal dust, cement, sulfate, nitrate and secondary organic matter. Secondary source, including secondary organic carbon(SOC),sulfate, nitrate, and ammonium(SNA), was always the main pollution source in this region.Dust, including cement and crustal dust, was important primary source. Encouragingly, coal combustion had been significantly controlled after APPCAP. The central site represented the higher contribution of vehicles, nitrates and SOC, while north and eastern sites showed the higher contribution of sulfate, coal combustion and dust. Many evidence points to substantial alterations in the physicochemical attributes of Chengdu's atmosphere. The rising proportion of nitrate and the transition of the atmospheric environment from ammoniapoor to ammonia-rich conditions highlight the necessity for the next phase of particulate matter control to focus intensively on the management of NH3and NOx. China's APPCAP could provide useful experience for vast developing countries and other urbanizing and industrializing regions to strike a balance between social development and environmental protection.展开更多
The risk of exposure to particulate matter(PM)has been consistently highlighted globally owing to its detrimental effects on the respiratory and cardiovascular systems and in the development of lung cancer.Additionall...The risk of exposure to particulate matter(PM)has been consistently highlighted globally owing to its detrimental effects on the respiratory and cardiovascular systems and in the development of lung cancer.Additionally,PM promotes cancer cell metastasis;however,research elucidating the precise mechanisms underlying this phenomenon and the strategies to inhibit it remains limited.The aim of this study was to elucidate the mechanism underlying PM-induced cancer metastasis and investigate the preventive role of ginsenoside Rg3.We treated macrophages with PM and confirmed an increase in the expression and secretion of chemokines,such as CCL3,CCL4,and CCL5.This effect was mediated by the MAPK and NF-kB pathways,and Rg3 inhibited this process by suppressing chemokine expression.These chemokines regulate the expression of epithelial-mesenchymal transition(EMT)markers in cancer cells,including Snail,Slug,ZEB1,and E-cadherin.The regulated EMT markers increased the motility of cancer cells in vitro.Furthermore,an increase in CCL3,CCL4,and CCL5 in the bronchoalveolar lavage fluid(BALF)was confirmed in a PM inhalation mouse model,and Rg3 reduced PM-induced cancer metastasis.The study findings suggest the potential use of Rg3 as a therapeutic agent to prevent PM-induced cancer metastasis.展开更多
Objective Emerging evidence suggests that exposure to ultrafine particulate matter(UPM,aerodynamic diameter<0.1μm)is associated with adverse cardiovascular events.Previous studies have found that Shenlian(SL)extra...Objective Emerging evidence suggests that exposure to ultrafine particulate matter(UPM,aerodynamic diameter<0.1μm)is associated with adverse cardiovascular events.Previous studies have found that Shenlian(SL)extract possesses anti-inflammatory and antiapoptotic properties and has a promising protective effect at all stages of the atherosclerotic disease process.In this study,we aimed to investigated whether SL improves UPM-aggravated myocardial ischemic injury by inhibiting inflammation and cell apoptosis.Methods We established a mouse model of MI+UPM.Echocardiographic measurement,measurement of myocardialinfarct size,biochemical analysis,enzyme-linked immunosorbent assay(ELISA),histopathological analysis,Transferase dUTP Nick End Labeling(TUNEL),Western blotting(WB),Polymerase Chain Reaction(PCR)and so on were used to explore the anti-inflammatory and antiapoptotic effects of SL in vivo and in vitro.Results SL treatment can attenuate UPM-induced cardiac dysfunction by improving left ventricular ejection fraction,fractional shortening,and decreasing cardiac infarction area.SL significantly reduced the levels of myocardial enzymes and attenuated UPM-induced morphological alterations.Moreover,SL significantly reduced expression levels of the inflammatory cytokines IL-6,TNF-α,and MCP-1.UPM further increased the infiltration of macrophages in myocardial tissue,whereas SL intervention reversed this phenomenon.UPM also triggered myocardial apoptosis,which was markedly attenuated by SL treatment.The results of in vitro experiments revealed that SL prevented cell damage caused by exposure to UPM combined with hypoxia by reducing the expression of the inflammatory factor NF-κB and inhibiting apoptosis in H9c2 cells.Conclusion Overall,both in vivo and in vitro experiments demonstrated that SL attenuated UPMaggravated myocardial ischemic injury by inhibiting inflammation and cell apoptosis.The mechanisms were related to the downregulation of macrophages infiltrating heart tissues.展开更多
To explore air contamination resulting from special biomass combustion and suspended dust in Lhasa,the present study focused on the size distribution and chemical characteristics of particulate matter(PM)emission resu...To explore air contamination resulting from special biomass combustion and suspended dust in Lhasa,the present study focused on the size distribution and chemical characteristics of particulate matter(PM)emission resulting from 7 types of non-fossil pollution sources.We investigated the concentration and size distribution of trace elements from 7 pollution sources collected in Lhasa.Combining Lhasa’s atmospheric particulate matter data,enrichment factors(EFs)have been calculated to examine the potential impact of those pollution sources on the atmosphere quality of Lhasa.The highest mass concentration of total elements of biomass combustion appeared at PM_(0.4),and the second highest concentration existed in the size fraction 0.4-1μm;the higher proportion(12%)of toxicmetals was produced by biomass combustion.The elemental composition of suspended dust and atmospheric particulate matter was close(except for As and Cd);the highest concentration of elements was all noted in PM_(2.5-10)(PM_(3-10)).Potassium was found to be one of the main biomass markers.The proportion of Cu in suspended dust is significantly lower than that of atmospheric particulate matter(0.53%and 3.75%),which indicates that there are other anthropogenic sources.The EFs analysis showed that the Cr,Cu,Zn,and Pb produced by biomass combustion were highly enriched(EFs>100)in all particle sizes.The EFs of most trace elements increased with decreasing particle size,indicating the greater influence of humanfactors on smaller particles.展开更多
This study presents an emission inventory for 2022,focusing on assessing the emissions of PM_(2.5),PM_(10),NO_(x),SO_(2),CO,and VOC from India's road transport,residential,and thermal power sectors.Road transport ...This study presents an emission inventory for 2022,focusing on assessing the emissions of PM_(2.5),PM_(10),NO_(x),SO_(2),CO,and VOC from India's road transport,residential,and thermal power sectors.Road transport emissions were estimated using a vehicle kilometer traveled methodology derived from a survey of 200,000 vehicles.A regression analysis was conducted to assess residential fuel usage,considering recent changes in consumption patterns and updated data on cleaner fuels.Estimates for the thermal power sector were based on emission monitoring data.The residential sector is the predominant source of PM_(2.5)(1112 kt),PM_(10)(1678 kt),CO(10630 kt),and VOC(2558 kt).The thermal power sector is the predominant source of secondary air pollutant precursors such as NO_(x)(2328 kt)and SO_(2)(4694 kt).India has the highest emission intensity per gross domestic product(GDP)across sectors compared to other countries.For example,PM_(2.5)emissions per GDP from the roads in India are 14,21,and 10 times that of those in China,the USA,and Europe.The southern(29%),eastern(30%),and central(36%)regions were the notable contributors to emissions from transport,residential,and thermal power sectors.Urban areas contributed 5%of the total residential sector emissions across India but 25%of the total road transport sector emissions nationwide.Moreover,power plants within or near the non-attainment cities were responsible for 12%of the overall thermal power pollution recorded across India.The study identifies unequal emission burdens,with economically disadvantaged regions bearing the brunt.展开更多
Serious fine particulate matter(PM_(2.5))pollution and rapidly increasing of ground-level ozone(O_(3))concentrations are concern issues in China.To achieve the comprehensive control of PM_(2.5)-O_(3) composite air pol...Serious fine particulate matter(PM_(2.5))pollution and rapidly increasing of ground-level ozone(O_(3))concentrations are concern issues in China.To achieve the comprehensive control of PM_(2.5)-O_(3) composite air pollution,exploring the common sources of PM_(2.5) and VOCs is essential.However,previous researches most carried out either PM_(2.5) or VOCs source appointment.In this study,we applied the ensemble source apportionment method to explore the impacts of common sources on PM_(2.5)-VOCs.Subsequently,we obtained the ensemble source impacts on O_(3) combining the extracted VOCs source profile and ozone formation potential.We found that the focus of environmentalmanagement and source control should be varied accordingly for different pollutants.Vehicle emission was the largest contributor(41%)to PM_(2.5)-VOCs,while industrial emission was the main common source(51%)to O_(3).The result showed that the O_(3) production rate is not only related to the VOCs emission,but also to the reactivity of VOCs.In addition,sensitivity tests revealed that temperature was the main factor affecting O_(3) formation.The study provides a framework to explore the common sources impact on PM_(2.5) and VOCs,which is benefit to address both PM_(2.5) and O_(3) mitigations.展开更多
Particulate photocatalytic systems using nanoscale photocatalysts have been developed as an attractive promising route for solar energy utilization to achieve resource sustainability and environmental harmony.Dynamic ...Particulate photocatalytic systems using nanoscale photocatalysts have been developed as an attractive promising route for solar energy utilization to achieve resource sustainability and environmental harmony.Dynamic obstacles are considered as the dominant inhibition for attaining satisfactory energy-conversion efficiency.The complexity in light absorption and carrier transfer behaviors has remained to be further clearly illuminated.It is challenging to trace the fast evolution of charge carriers involved in transfer migration and interfacial reactions within a micro–nano-single-particle photocatalyst,which requires spatiotemporal high resolution.In this review,comprehensive dynamic descriptions including irradiation field,carrier separation and transfer,and interfacial reaction processes have been elucidated and discussed.The corresponding mechanisms for revealing dynamic behaviors have been explained.In addition,numerical simulation and modeling methods have been illustrated for the description of the irradiation field.Experimental measurements and spatiotemporal characterizations have been clarified for the reflection of carrier behavior and probing detection of interfacial reactions.The representative applications have been introduced according to the reported advanced research works,and the relationships between mechanistic conclusions from variable spatiotemporal measurements and photocatalytic performance results in the specific photocatalytic reactions have been concluded.This review provides a collective perspective for the full understanding and thorough evaluation of the primary dynamic processes,which would be inspired for the improvement in designing solar-driven energy-conversion systems based on nanoscale particulate photocatalysts.展开更多
One of the most important of these emissions is fine particulate matter,which is a harmful emission of diesel engines,leading to the imposition of strict regulations.Biodiesel,with its high oxygen content,is an effect...One of the most important of these emissions is fine particulate matter,which is a harmful emission of diesel engines,leading to the imposition of strict regulations.Biodiesel,with its high oxygen content,is an effective alternative to significantly reduce these emissions.In this study,rapeseed methyl ester(RME)was used as a diesel engine fuel and the emitted particulate matter was comparedwith ultra-lowsulfur diesel(ULSD).Inmost experimental studies,the emission of soot wasmeasured.In this work,the effects of injection timing,injection pressure(IP),and engine load on fine particulate matter in both nucleation and accumulation modes were studied.The results show that IP increases the number of particles in the accumulation mode while the number of particles in the crystallization mode is higher for rapeseed methyl ester(RME)than for ultra-low sulfur diesel(ULSD).Conversely,the formation rates of particles in the accumulationmode are higher for ULSD.Cumulative concentration numbers(CCN)are generally higher for RME in crystallization mode but higher for ULSD in accumulation mode.Increasing the IP reduces the CCN values.The particle size in crystallizationmode reaches a maximum of 22 nm at IPs of 800 and 1000 bar but decreases to 15 nm at 1200 bar.Most fine particles fall in the 5–100 nm diameter range.High engine loads reduce the particle size distribution in nucleationmode for both fuels,with a slight increase in particle size in nucleationmode.Thestudy concluded that the use of rapeseed methyl ester as an engine fuel benefits the environment and improves air quality due to the significant reduction in the size,number,and concentration of nano-soot particles and total particles emitted from the engine.展开更多
Particulate organic matter(POM)plays a crucial role in the organic composition of lakes;however,its characteristics remain poorly understood.This study aimed to characterize the structure and composition of POM in Lak...Particulate organic matter(POM)plays a crucial role in the organic composition of lakes;however,its characteristics remain poorly understood.This study aimed to characterize the structure and composition of POM in Lake Baiyangdian usingmany kinds of techniques and investigate the effects of different extracted forms of POM on water quality.The suspended particulatematter in the lake had complex compositions,with its components primarily derived from aquatic plants and their detritus.The organic matter content of the suspended particulatematterwas relatively high(organic carbon content 27.29–145.94 g/kg)for the sum of three extractable states(water-extracted organic matter[WEOM],humic acid,and fulvic acid)and one stable bound state(humin).Spatial distribution analysis revealed that the POM content in the water increased from west to east,which was consistent with the water flow pattern influenced by the Baiyangdian water diversion project.Fluorescence spectroscopy analysis of the WEOM showed three prominent peaks with excitation/emission wavelengths similar to those of dissolved organic matter peaks.These peaks were potentially initial products of POM conversion into dissolved organic matter.Furthermore,the intensity of the WEOM fluorescence peak(total fluorescence peak intensity)was negatively correlated with the inorganic nitrogen concentration in water(p<0.01),while the intensity of the HA fluorescence peak showed a positive correlation with the inorganic nitrogen concentration(p<0.01).This suggested that exogenous organic matter inputs led to the diffusion of alkaline dissolved nitrogen from sediment intowater,while degradation processes of aquatic plant debris contributed to the decrease in inorganic nitrogen concentrations in the water column.These findings enhance our understanding of POM characteristics in shallow lakes and the role of POM in shallow lake ecosystems.展开更多
Many studies have shown the negative relationship between long term exposure to PM_(2.5)and cardiac dysfunction.Recently,studies have shown that even a single exposure of PM_(2.5)from air sample in permissible range c...Many studies have shown the negative relationship between long term exposure to PM_(2.5)and cardiac dysfunction.Recently,studies have shown that even a single exposure of PM_(2.5)from air sample in permissible range can induce very mild cardiac pathological changes.In the present study,we revisited the toxic effect of PM_(2.5)on rat heart by adopting single and multiple exposure durations.FemaleWistar ratswere exposed to PM_(2.5)at a concentration of 250μg/m3 daily for 3 hr for single(1 day)and multiple(7,14,21 days)durations.The major pathological changes noted in 21 days exposed myocardium comprised of an elevated ST segment(the segment between the S wave and the T wave),development of cardiac fibrosis,hypertrophy,cardiac injury,tissue inflammation and declined cardiac function.With 14 days exposed heart,the electrocardiograms(ECG),data showed insignificantly declined heart rate and an increased QT(the time from the start of the Q wave to the end of the T wave)interval along with mild fibrosis,hypertrophy and lesser number of TUNEL positive cells.On the other hand,single-and 7-days exposure to PM_(2.5)did not impart any significant changes in the myocardium.To determine the reversibility potential of PM_(2.5)induced cardiotoxicity,a washout period of 24 hours was adopted and all observed changes in the myocardium were reversed till day 7,but not in 14-and 21-days exposed samples.Based on the above findings we concluded that PM_(2.5)associated cardiac dysfunction is the cumulative outcome of ineffective cardiac adaptive and repair process that accumulate additively over the time due to prolonged exposure durations.展开更多
The increasing severity of air pollution necessitates more effective and sustained air filtration technology.Concurrently,the desire for more environmentally friendly,sustainable materials with better filtering perfor...The increasing severity of air pollution necessitates more effective and sustained air filtration technology.Concurrently,the desire for more environmentally friendly,sustainable materials with better filtering performance and less environmental impact drives the move away from conventional synthetic membranes.This review presents lignocellulosic biocomposite(LigBioComp)membranes as an alternative to traditional synthetic membranes.It focuses on their materials,fabrication,and functionalization techniques while exploring challenges and proposing methods for resourceful utilization.Renowned for their abundance and renewable nature,lignocellulosic materials consist of cellulose,hemicellulose,and lignin.Various applications can benefit from their antibacterial properties,large surface area,and remarkable mechanical strength.LigBioComp membranes are fabricated through casting,electrospinning,and freeze-drying,with advancements in fabrication techniques enhancing their performance and applicability.It is suggested to use solvent-free or low-solvent techniques such as Layer-by-Layer assembly to minimize environmental impact.Freeze-drying and electrospinning with green solvents can be used for achieving specific membrane properties,though energy consumption should be considered.Apply dry-wet spinning and solvent casting processes selectively.Functional groups,including carboxyl,hydroxyl,or amino groups,can significantly improve the membrane’s capacity to capture particulate matter.Chemical etching or the precise deposition of nanoparticles can further optimize pore size and distribution.The choice of chemicals and methods is critical in functionalization,with silane coupling agents,polyethyleneimine,and polydopamine.Future research should prioritize refining fabrication methods,advancing functionalization strategies,and conducting performance and recyclability assessments on hybrid and composite materials.This will enhance integrated systems and contribute to the development of smart filters.展开更多
The heritage preservation is of great intractability to the conservators as each kind of heritage material has unique and diverse requirements on temperature,humidity and air cleanliness.It is promising for metal-orga...The heritage preservation is of great intractability to the conservators as each kind of heritage material has unique and diverse requirements on temperature,humidity and air cleanliness.It is promising for metal-organic frameworks(MOFs),the multifunctional environment remediation materials,to be applied in heritage environmental protection.The advantages of MOFs lie in their multifunction like adsorption,photocatalysis,sterilization,as well as the controllable structure and properties that could be flexibly adjusted as demands,helping the heritage against various environmental threats.Thereby,the applications and the corresponding mechanisms of MOFs in cultural heritage preservation were reviewed in this work,including harmful gas adsorption,surface waterproofing,particulate matters(PM)removal,anti-bacterial and humidity control of environment.Finally,the selection principles and precautions of MOFs in heritage preservation were discussed,aiming to provide a forward-looking direction for the selection and application of MOFs.展开更多
This work used 5CrMnMo steel and titanium carbide(TiC)powders to fabricate particulate metal matrix composites(PMMCS).The composites’microstructure,hardness,and impact toughness were compared with four different tita...This work used 5CrMnMo steel and titanium carbide(TiC)powders to fabricate particulate metal matrix composites(PMMCS).The composites’microstructure,hardness,and impact toughness were compared with four different titanium carbide ceramic particle sizes.The phase composition and microstructure of composites were studied.Vickers hardness and Charpy impact tests were employed to analyze composites’hardness and impact ductility,respectively.The results showed that the four groups of composites are mainly composed of martensite,trace residual austenite,and titanium carbide(undissolved TiC and primary TiC particles).With the growth of the ceramic particle dimension in the composite layer,the number of primary titanium carbide ceramics gradually decreased.When the initial ceramic particle size was small,it tended to generate dendritic primary TiC,and when the particle size was large,it tended to generate polygons and ellipsoids.Furthermore,with the growth of titanium carbide ceramic particle dimension in the composites,the hardness of the composites decreased but the impact toughness of the composites rose first and then descended.When the ceramic particle size was 50-75μm,the composite had the highest hardness,and the impact energy of the composites was the highest,which is 8 J.This was because there were more undissolved titanium carbide ceramics in the composite,and there was a thicker matrix metal between the ceramic particles.展开更多
Catalyzed gasoline particulate filters(cGPFs)are being developed to enable compliance with the particulate number limits for passenger cars equipped with gasoline direct injection(GDI)engines in China and Europe,It is...Catalyzed gasoline particulate filters(cGPFs)are being developed to enable compliance with the particulate number limits for passenger cars equipped with gasoline direct injection(GDI)engines in China and Europe,It is appealing to build catalysts with ceria—an irreplaceable"reducible"component in three-way converters—to help eliminate the soot particles trapped in cGPFs via O_(2)-assisted combustion.While research aiming at understanding how these recipes function has continued for more than two decades,a universal model elucidating the roles of different"active oxygen"species is yet to be realized.In this perspective,by critically assessing the reported data about gasoline soot catalytic combustion over ceria catalysts,it is suggested that ceria ignites soot through contributing its lattice oxygen,giving rise to a"hot ring"region at the periphery of soot-catalyst interface.During the"re-oxidation"semi-cycles,electrophilic superoxides and/or peroxides(O_(x)^(n-))are produced at the Ce^(3+)and oxygen vacancy sites enriched in this collar-like region,and then work as key reactive phases for soot deep oxidation.Based on this"O_(x)^(n-)assisted"Mars-van Krevelen mechanism,several guidelines for ceria catalyst designing are proposed,ending with a summary about where future opportunities and challenges may lie in developing efficient and practical cGPF catalysts.展开更多
Phthalate(PAEs)and Bisphenols(BPs)are plasticizers or additives in consumer products.They are typical endocrine disruptors,and potential health hazards may occur when people are exposed to them through inhalation,inge...Phthalate(PAEs)and Bisphenols(BPs)are plasticizers or additives in consumer products.They are typical endocrine disruptors,and potential health hazards may occur when people are exposed to them through inhalation,ingestion,and dermal contact.The current research on inhalation exposure pays limited attention to the particle distribution of PAEs and BPs in air,although particulate-bound pollutants are usually size-dependent.In this study,we discussed the size resolution of PAEs and BPs in air particles from city waste recycling plants.With paired urine samples of the workers,we also compared the internal and external exposure of PAEs and BPs and related potential health risks.The particulatebound PAEs and BPs concentrated mainly on coarse particles(Dp>2.1μm),with a bimodal distribution,and the peak particle size ranged from 9–10 to 4.7–5.85μm,respectively.Model calculation revealed that the deposition fluxes of PAEs in different respiratory regions followed the sequence of head airways(167±92.8 ng/h)>alveolar region(18.9±9.96 ng/h)>tracheobronchial region(9.20±5.22 ng/h),and the similar trends went for BPs.The daily intakes of PAEs and BPs via dust ingestion were higher than those fromrespiratory inhalation and dermal contact,with mean value of 96 and 0.88 ng/(kg-bw day),respectively.For internal exposure,the estimated daily intakes of PAEs for waste recycling workers were higher than those in e-waste dismantling workers,while the exposure levels of bisphenols were comparable.Overall,the potential health risks from inhalation exposure to particulate-bound PAEs and BPs were low.展开更多
Objective Chronic obstructive pulmonary disease(COPD)is a major health concern in northwest China;however,the impact of particulate matter(PM)exposure during sand-dust storms(SDS)remains poorly understood.Therefore,th...Objective Chronic obstructive pulmonary disease(COPD)is a major health concern in northwest China;however,the impact of particulate matter(PM)exposure during sand-dust storms(SDS)remains poorly understood.Therefore,this study aimed to investigate the association between PM exposure on SDS days and COPD hospitalization risk in arid regions.Methods Data on daily COPD hospitalizations were collected from 323 hospitals from 2018 to 2022,along with the corresponding air pollutant and meteorological data for each city in Gansu Province.Employing a space-time-stratified case-crossover design and conditional Poisson regression,we analyzed 265,379 COPD hospitalizations.Results PM exposure during SDS days significantly increased COPD hospitalization risk[relative risk(RR)for PM2.5,lag 3:1.028,95%confidence interval(CI):1.021–1.034],particularly among men and the elderly,and during the cold season.The burden of PM exposure on COPD hospitalization was substantially high in Northwest China,especially in the arid and semi-arid regions.Conclusion Our findings revealed a positive correlation between PM exposure during SDS episodes and elevated hospitalization rates for COPD in arid and semi-arid zones in China.This highlights the urgency of developing region-specific public health strategies to address adverse respiratory outcomes associated with SDS-related air quality deterioration.展开更多
Oxygenated fuels can reduce harmful emissions without affecting engine performance,meeting the big challenge in the transportation industry,which keeps the environment safe and reduces global warming.This study invest...Oxygenated fuels can reduce harmful emissions without affecting engine performance,meeting the big challenge in the transportation industry,which keeps the environment safe and reduces global warming.This study investigates the impact of biodiesel injection strategies and fuel injection pressures(FIP)on diesel engine exhaust emission characteristics.The engine is fuelled with 20%Jatropha biodiesel(JB)and 80%diesel,named JB20D.The ratios of fuel injection pressures started with injecting the fuel(diesel and JB20D)from 200 bar to 500 bar.The experimental outcomes indicate that the engine performance of brake-specific fuel consumption increased by 21.36%from the burning of JB20D compared with diesel,while brake thermal efficiency improved by 6.54%for low and high FIP compared to the diesel.The high fuel injection pressures slightly decrease the nitrogen oxide(NOX)emissions for both diesel and biodiesel.The emissions of NOX decreased from the combustion of JB20D by 18.7%under high fuel injection pressures compared to diesel.The concentration of soot particulate decreased by 20.4%form JB20D combustion than those combusted from diesel fuel.展开更多
基金supported by the National Natural Science Foundation of China(No.42205178)China Postdoctoral Science Foundation(No.2022M720459).
文摘With the continuous control of anthropogenic emissions,China’s air quality has improved significantly in recent years.Given this background,research on how the short-term exposure risks caused by air pollution in China have changed is insufficient.This study utilized hourly concentration data from ground observation stations and the official air quality guidelines of the Ministry of Ecology and Environment of China and the World Health Organization as standards to systematically investigate the spatiotemporal characteristics and short-term exposure risks of air pollution in China from 2015 to 2022.The results indicate that various atmospheric pollutants except for ozone showed a decreasing trend yearly.Nationwide,both single pollutant air pollution days(SAPDs)and multiple pollutant air pollution days(MAPDs)showed varying degrees of reduction within 15 and 25 days,respectively.SAPD was dominated mainly by excessive PM_(2.5)and PM_(10)pollutants,while MAPD was dominated mainly by excessive pollutant combinations,including PM_(2.5)+PM_(10),CO+PM_(2.5)+PM_(10),and SO_(2)+PM_(2.5)+PM_(10).As the concentration of atmospheric pollutants decreased,the total excess risk(ER)decreased yearly from 2015 to 2022,but there were significant regional differences.Now,the ER is less than 0.25%in southern China,in the range of 0.25%-0.5%in the North China Plain and some cities in the northeast,and higher than 1%in the northwest.Particulate matter is currently the primary pollutant posing short-term exposure risk in China,especially due to the impact of sandstorm weather.This study indicates that China’s atmospheric cleaning action is significantly beneficial for reducing health risks.
文摘Fine particulate matter(particulate matter with a diameter of 2.5μm or less;PM2.5)causes millions of premature deaths globally1,but not all particles are equally harmful2-4.Current air-pollution control strategies,prioritizing PM2.5 mass reduction,have provided considerable health benefits but further refinements based on differences in the toxicity of various emission sources may provide greater benefits5-7.Here we integrated field measurements with air-quality modelling to assess the unequal toxicities of PM2.5 from various anthropogenic sources.
文摘A hydrodynamic model is used to study Kelvin-Helmholtz(KH)instability of the interface between two particle-laden inviscid fluids moving with two different uniform mean velocities.Explicit eigen-equation is derived to study the effect of suspended particles on the growth rate of KH instability.For dusty gases with negligible volume fraction of heavy particles and small particle-to-fluid mass ratio,the real and imaginary parts of leading-order asymptotic expression derived by the present model for the growth rate are shown to be identical to the earlier results derived by the classical Saffman model established for dusty gases.Beyond the known results,explicit leading-order asymptotic expressions for the effect of suspended particles on the growth rate are derived for several typical cases of basic interest.It is shown that the suspended particles can decrease or increase the growth rate of KH instability depending on the Stokes numbers of the particles and whether the particles are heavier or lighter than the clean fluid.Compared to the mass density of the clean fluid,our results based on leading-order asymptotic solutions show that heavier particles and lighter particles have opposite effects on the growth rate of KH instability,while the effect of neutrally buoyant particles on the growth rate of KH instability is negligible.
基金supported by the National Natural Science Foundation of China (No.42177085)。
文摘A long-term(2007-2016) particulate matter dataset measured at multiple sites in Chengdu,an expanding megacity in southwest China, was analyzed. The trends of particulate chemical compositions and source apportionment were used to evaluate and review the effectiveness of source-specific control policies and measures in Atmospheric Pollution Prevention and Control Action Plan(APPCAP). The concentration of particulate matter decreased significantly, and most aerosol components changed synchronously with particulate matter. The results of advanced three-way factor analysis model suggested that six sources were resolved at three sites: coal combustion, vehicle, crustal dust, cement, sulfate, nitrate and secondary organic matter. Secondary source, including secondary organic carbon(SOC),sulfate, nitrate, and ammonium(SNA), was always the main pollution source in this region.Dust, including cement and crustal dust, was important primary source. Encouragingly, coal combustion had been significantly controlled after APPCAP. The central site represented the higher contribution of vehicles, nitrates and SOC, while north and eastern sites showed the higher contribution of sulfate, coal combustion and dust. Many evidence points to substantial alterations in the physicochemical attributes of Chengdu's atmosphere. The rising proportion of nitrate and the transition of the atmospheric environment from ammoniapoor to ammonia-rich conditions highlight the necessity for the next phase of particulate matter control to focus intensively on the management of NH3and NOx. China's APPCAP could provide useful experience for vast developing countries and other urbanizing and industrializing regions to strike a balance between social development and environmental protection.
基金supported by the KIST Institutional Program(No.2E31700-22-P005)the KRIBB Research Initiative Program(No.KGM5322422)+1 种基金the Technology Innovation Program(No.20008826)funded by the Ministry of Trade,Industry and Energy(MOTIE,Republic of Korea)the National Research Foundation of Korea(NRF)(No.2022R1A2C1091865)funded by the Ministry of Science and ICT(MSIT,Republic of Korea)。
文摘The risk of exposure to particulate matter(PM)has been consistently highlighted globally owing to its detrimental effects on the respiratory and cardiovascular systems and in the development of lung cancer.Additionally,PM promotes cancer cell metastasis;however,research elucidating the precise mechanisms underlying this phenomenon and the strategies to inhibit it remains limited.The aim of this study was to elucidate the mechanism underlying PM-induced cancer metastasis and investigate the preventive role of ginsenoside Rg3.We treated macrophages with PM and confirmed an increase in the expression and secretion of chemokines,such as CCL3,CCL4,and CCL5.This effect was mediated by the MAPK and NF-kB pathways,and Rg3 inhibited this process by suppressing chemokine expression.These chemokines regulate the expression of epithelial-mesenchymal transition(EMT)markers in cancer cells,including Snail,Slug,ZEB1,and E-cadherin.The regulated EMT markers increased the motility of cancer cells in vitro.Furthermore,an increase in CCL3,CCL4,and CCL5 in the bronchoalveolar lavage fluid(BALF)was confirmed in a PM inhalation mouse model,and Rg3 reduced PM-induced cancer metastasis.The study findings suggest the potential use of Rg3 as a therapeutic agent to prevent PM-induced cancer metastasis.
基金supported by CACMS Innovation Fund(No CI2021A04611,CI2021A05106)Scientific and technological innovation project of China Academy of Chinese Medical Sciences(CI2021B015)+1 种基金Scientific and technological innovation project of China Academy of Chinese Medical Sciences(CI2023E001TS01)Fundamental research funds for the central public welfare research institutes(L2022035).
文摘Objective Emerging evidence suggests that exposure to ultrafine particulate matter(UPM,aerodynamic diameter<0.1μm)is associated with adverse cardiovascular events.Previous studies have found that Shenlian(SL)extract possesses anti-inflammatory and antiapoptotic properties and has a promising protective effect at all stages of the atherosclerotic disease process.In this study,we aimed to investigated whether SL improves UPM-aggravated myocardial ischemic injury by inhibiting inflammation and cell apoptosis.Methods We established a mouse model of MI+UPM.Echocardiographic measurement,measurement of myocardialinfarct size,biochemical analysis,enzyme-linked immunosorbent assay(ELISA),histopathological analysis,Transferase dUTP Nick End Labeling(TUNEL),Western blotting(WB),Polymerase Chain Reaction(PCR)and so on were used to explore the anti-inflammatory and antiapoptotic effects of SL in vivo and in vitro.Results SL treatment can attenuate UPM-induced cardiac dysfunction by improving left ventricular ejection fraction,fractional shortening,and decreasing cardiac infarction area.SL significantly reduced the levels of myocardial enzymes and attenuated UPM-induced morphological alterations.Moreover,SL significantly reduced expression levels of the inflammatory cytokines IL-6,TNF-α,and MCP-1.UPM further increased the infiltration of macrophages in myocardial tissue,whereas SL intervention reversed this phenomenon.UPM also triggered myocardial apoptosis,which was markedly attenuated by SL treatment.The results of in vitro experiments revealed that SL prevented cell damage caused by exposure to UPM combined with hypoxia by reducing the expression of the inflammatory factor NF-κB and inhibiting apoptosis in H9c2 cells.Conclusion Overall,both in vivo and in vitro experiments demonstrated that SL attenuated UPMaggravated myocardial ischemic injury by inhibiting inflammation and cell apoptosis.The mechanisms were related to the downregulation of macrophages infiltrating heart tissues.
基金supported by the Natural Science Foundation of China (No.11775180).
文摘To explore air contamination resulting from special biomass combustion and suspended dust in Lhasa,the present study focused on the size distribution and chemical characteristics of particulate matter(PM)emission resulting from 7 types of non-fossil pollution sources.We investigated the concentration and size distribution of trace elements from 7 pollution sources collected in Lhasa.Combining Lhasa’s atmospheric particulate matter data,enrichment factors(EFs)have been calculated to examine the potential impact of those pollution sources on the atmosphere quality of Lhasa.The highest mass concentration of total elements of biomass combustion appeared at PM_(0.4),and the second highest concentration existed in the size fraction 0.4-1μm;the higher proportion(12%)of toxicmetals was produced by biomass combustion.The elemental composition of suspended dust and atmospheric particulate matter was close(except for As and Cd);the highest concentration of elements was all noted in PM_(2.5-10)(PM_(3-10)).Potassium was found to be one of the main biomass markers.The proportion of Cu in suspended dust is significantly lower than that of atmospheric particulate matter(0.53%and 3.75%),which indicates that there are other anthropogenic sources.The EFs analysis showed that the Cr,Cu,Zn,and Pb produced by biomass combustion were highly enriched(EFs>100)in all particle sizes.The EFs of most trace elements increased with decreasing particle size,indicating the greater influence of humanfactors on smaller particles.
文摘This study presents an emission inventory for 2022,focusing on assessing the emissions of PM_(2.5),PM_(10),NO_(x),SO_(2),CO,and VOC from India's road transport,residential,and thermal power sectors.Road transport emissions were estimated using a vehicle kilometer traveled methodology derived from a survey of 200,000 vehicles.A regression analysis was conducted to assess residential fuel usage,considering recent changes in consumption patterns and updated data on cleaner fuels.Estimates for the thermal power sector were based on emission monitoring data.The residential sector is the predominant source of PM_(2.5)(1112 kt),PM_(10)(1678 kt),CO(10630 kt),and VOC(2558 kt).The thermal power sector is the predominant source of secondary air pollutant precursors such as NO_(x)(2328 kt)and SO_(2)(4694 kt).India has the highest emission intensity per gross domestic product(GDP)across sectors compared to other countries.For example,PM_(2.5)emissions per GDP from the roads in India are 14,21,and 10 times that of those in China,the USA,and Europe.The southern(29%),eastern(30%),and central(36%)regions were the notable contributors to emissions from transport,residential,and thermal power sectors.Urban areas contributed 5%of the total residential sector emissions across India but 25%of the total road transport sector emissions nationwide.Moreover,power plants within or near the non-attainment cities were responsible for 12%of the overall thermal power pollution recorded across India.The study identifies unequal emission burdens,with economically disadvantaged regions bearing the brunt.
基金supported by the National Key Research and Development Program of China(Nos.2023YFC3709500,2023YFC3709502 and 2022YFC3703400)the National Natural Science Foundation of China(No.42077191)+1 种基金the Fundamental Research Funds for the Central Universities(No.63233054)Tianjin Science and Technology Plan Project(No.18PTZWHZ00120).
文摘Serious fine particulate matter(PM_(2.5))pollution and rapidly increasing of ground-level ozone(O_(3))concentrations are concern issues in China.To achieve the comprehensive control of PM_(2.5)-O_(3) composite air pollution,exploring the common sources of PM_(2.5) and VOCs is essential.However,previous researches most carried out either PM_(2.5) or VOCs source appointment.In this study,we applied the ensemble source apportionment method to explore the impacts of common sources on PM_(2.5)-VOCs.Subsequently,we obtained the ensemble source impacts on O_(3) combining the extracted VOCs source profile and ozone formation potential.We found that the focus of environmentalmanagement and source control should be varied accordingly for different pollutants.Vehicle emission was the largest contributor(41%)to PM_(2.5)-VOCs,while industrial emission was the main common source(51%)to O_(3).The result showed that the O_(3) production rate is not only related to the VOCs emission,but also to the reactivity of VOCs.In addition,sensitivity tests revealed that temperature was the main factor affecting O_(3) formation.The study provides a framework to explore the common sources impact on PM_(2.5) and VOCs,which is benefit to address both PM_(2.5) and O_(3) mitigations.
基金supported by the Project of National Natural Science Foundation of China(22102095,21773153)the National Key Basic Research and Development Program(2018YFB1502001)financial support from the program of China Scholarships Council(No.202306230242).
文摘Particulate photocatalytic systems using nanoscale photocatalysts have been developed as an attractive promising route for solar energy utilization to achieve resource sustainability and environmental harmony.Dynamic obstacles are considered as the dominant inhibition for attaining satisfactory energy-conversion efficiency.The complexity in light absorption and carrier transfer behaviors has remained to be further clearly illuminated.It is challenging to trace the fast evolution of charge carriers involved in transfer migration and interfacial reactions within a micro–nano-single-particle photocatalyst,which requires spatiotemporal high resolution.In this review,comprehensive dynamic descriptions including irradiation field,carrier separation and transfer,and interfacial reaction processes have been elucidated and discussed.The corresponding mechanisms for revealing dynamic behaviors have been explained.In addition,numerical simulation and modeling methods have been illustrated for the description of the irradiation field.Experimental measurements and spatiotemporal characterizations have been clarified for the reflection of carrier behavior and probing detection of interfacial reactions.The representative applications have been introduced according to the reported advanced research works,and the relationships between mechanistic conclusions from variable spatiotemporal measurements and photocatalytic performance results in the specific photocatalytic reactions have been concluded.This review provides a collective perspective for the full understanding and thorough evaluation of the primary dynamic processes,which would be inspired for the improvement in designing solar-driven energy-conversion systems based on nanoscale particulate photocatalysts.
文摘One of the most important of these emissions is fine particulate matter,which is a harmful emission of diesel engines,leading to the imposition of strict regulations.Biodiesel,with its high oxygen content,is an effective alternative to significantly reduce these emissions.In this study,rapeseed methyl ester(RME)was used as a diesel engine fuel and the emitted particulate matter was comparedwith ultra-lowsulfur diesel(ULSD).Inmost experimental studies,the emission of soot wasmeasured.In this work,the effects of injection timing,injection pressure(IP),and engine load on fine particulate matter in both nucleation and accumulation modes were studied.The results show that IP increases the number of particles in the accumulation mode while the number of particles in the crystallization mode is higher for rapeseed methyl ester(RME)than for ultra-low sulfur diesel(ULSD).Conversely,the formation rates of particles in the accumulationmode are higher for ULSD.Cumulative concentration numbers(CCN)are generally higher for RME in crystallization mode but higher for ULSD in accumulation mode.Increasing the IP reduces the CCN values.The particle size in crystallizationmode reaches a maximum of 22 nm at IPs of 800 and 1000 bar but decreases to 15 nm at 1200 bar.Most fine particles fall in the 5–100 nm diameter range.High engine loads reduce the particle size distribution in nucleationmode for both fuels,with a slight increase in particle size in nucleationmode.Thestudy concluded that the use of rapeseed methyl ester as an engine fuel benefits the environment and improves air quality due to the significant reduction in the size,number,and concentration of nano-soot particles and total particles emitted from the engine.
基金supported by the National Key Research and Development Program of China(No.2022YFC3204003)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Wenqiang Zhang,No.2018058).
文摘Particulate organic matter(POM)plays a crucial role in the organic composition of lakes;however,its characteristics remain poorly understood.This study aimed to characterize the structure and composition of POM in Lake Baiyangdian usingmany kinds of techniques and investigate the effects of different extracted forms of POM on water quality.The suspended particulatematter in the lake had complex compositions,with its components primarily derived from aquatic plants and their detritus.The organic matter content of the suspended particulatematterwas relatively high(organic carbon content 27.29–145.94 g/kg)for the sum of three extractable states(water-extracted organic matter[WEOM],humic acid,and fulvic acid)and one stable bound state(humin).Spatial distribution analysis revealed that the POM content in the water increased from west to east,which was consistent with the water flow pattern influenced by the Baiyangdian water diversion project.Fluorescence spectroscopy analysis of the WEOM showed three prominent peaks with excitation/emission wavelengths similar to those of dissolved organic matter peaks.These peaks were potentially initial products of POM conversion into dissolved organic matter.Furthermore,the intensity of the WEOM fluorescence peak(total fluorescence peak intensity)was negatively correlated with the inorganic nitrogen concentration in water(p<0.01),while the intensity of the HA fluorescence peak showed a positive correlation with the inorganic nitrogen concentration(p<0.01).This suggested that exogenous organic matter inputs led to the diffusion of alkaline dissolved nitrogen from sediment intowater,while degradation processes of aquatic plant debris contributed to the decrease in inorganic nitrogen concentrations in the water column.These findings enhance our understanding of POM characteristics in shallow lakes and the role of POM in shallow lake ecosystems.
基金the Indian Council of Medical Research(No.3/1/2(22)/Env/2021-NCD-II)Department of science and technology,India(CRG/2021/000227)for funding this research.
文摘Many studies have shown the negative relationship between long term exposure to PM_(2.5)and cardiac dysfunction.Recently,studies have shown that even a single exposure of PM_(2.5)from air sample in permissible range can induce very mild cardiac pathological changes.In the present study,we revisited the toxic effect of PM_(2.5)on rat heart by adopting single and multiple exposure durations.FemaleWistar ratswere exposed to PM_(2.5)at a concentration of 250μg/m3 daily for 3 hr for single(1 day)and multiple(7,14,21 days)durations.The major pathological changes noted in 21 days exposed myocardium comprised of an elevated ST segment(the segment between the S wave and the T wave),development of cardiac fibrosis,hypertrophy,cardiac injury,tissue inflammation and declined cardiac function.With 14 days exposed heart,the electrocardiograms(ECG),data showed insignificantly declined heart rate and an increased QT(the time from the start of the Q wave to the end of the T wave)interval along with mild fibrosis,hypertrophy and lesser number of TUNEL positive cells.On the other hand,single-and 7-days exposure to PM_(2.5)did not impart any significant changes in the myocardium.To determine the reversibility potential of PM_(2.5)induced cardiotoxicity,a washout period of 24 hours was adopted and all observed changes in the myocardium were reversed till day 7,but not in 14-and 21-days exposed samples.Based on the above findings we concluded that PM_(2.5)associated cardiac dysfunction is the cumulative outcome of ineffective cardiac adaptive and repair process that accumulate additively over the time due to prolonged exposure durations.
基金funded by the Universiti Teknologi Malaysia(UTM)through research Grant Number:06E05.
文摘The increasing severity of air pollution necessitates more effective and sustained air filtration technology.Concurrently,the desire for more environmentally friendly,sustainable materials with better filtering performance and less environmental impact drives the move away from conventional synthetic membranes.This review presents lignocellulosic biocomposite(LigBioComp)membranes as an alternative to traditional synthetic membranes.It focuses on their materials,fabrication,and functionalization techniques while exploring challenges and proposing methods for resourceful utilization.Renowned for their abundance and renewable nature,lignocellulosic materials consist of cellulose,hemicellulose,and lignin.Various applications can benefit from their antibacterial properties,large surface area,and remarkable mechanical strength.LigBioComp membranes are fabricated through casting,electrospinning,and freeze-drying,with advancements in fabrication techniques enhancing their performance and applicability.It is suggested to use solvent-free or low-solvent techniques such as Layer-by-Layer assembly to minimize environmental impact.Freeze-drying and electrospinning with green solvents can be used for achieving specific membrane properties,though energy consumption should be considered.Apply dry-wet spinning and solvent casting processes selectively.Functional groups,including carboxyl,hydroxyl,or amino groups,can significantly improve the membrane’s capacity to capture particulate matter.Chemical etching or the precise deposition of nanoparticles can further optimize pore size and distribution.The choice of chemicals and methods is critical in functionalization,with silane coupling agents,polyethyleneimine,and polydopamine.Future research should prioritize refining fabrication methods,advancing functionalization strategies,and conducting performance and recyclability assessments on hybrid and composite materials.This will enhance integrated systems and contribute to the development of smart filters.
基金supported by the National Natural Science Foundation of China(Nos.52308300,52370025,52108266).
文摘The heritage preservation is of great intractability to the conservators as each kind of heritage material has unique and diverse requirements on temperature,humidity and air cleanliness.It is promising for metal-organic frameworks(MOFs),the multifunctional environment remediation materials,to be applied in heritage environmental protection.The advantages of MOFs lie in their multifunction like adsorption,photocatalysis,sterilization,as well as the controllable structure and properties that could be flexibly adjusted as demands,helping the heritage against various environmental threats.Thereby,the applications and the corresponding mechanisms of MOFs in cultural heritage preservation were reviewed in this work,including harmful gas adsorption,surface waterproofing,particulate matters(PM)removal,anti-bacterial and humidity control of environment.Finally,the selection principles and precautions of MOFs in heritage preservation were discussed,aiming to provide a forward-looking direction for the selection and application of MOFs.
基金supported by the Equipment Pre-research and Sharing Technology(41423030503)provided funding for this workThe Equipment Pre-research and Sharing Technology(41423030503)funded this work.
文摘This work used 5CrMnMo steel and titanium carbide(TiC)powders to fabricate particulate metal matrix composites(PMMCS).The composites’microstructure,hardness,and impact toughness were compared with four different titanium carbide ceramic particle sizes.The phase composition and microstructure of composites were studied.Vickers hardness and Charpy impact tests were employed to analyze composites’hardness and impact ductility,respectively.The results showed that the four groups of composites are mainly composed of martensite,trace residual austenite,and titanium carbide(undissolved TiC and primary TiC particles).With the growth of the ceramic particle dimension in the composite layer,the number of primary titanium carbide ceramics gradually decreased.When the initial ceramic particle size was small,it tended to generate dendritic primary TiC,and when the particle size was large,it tended to generate polygons and ellipsoids.Furthermore,with the growth of titanium carbide ceramic particle dimension in the composites,the hardness of the composites decreased but the impact toughness of the composites rose first and then descended.When the ceramic particle size was 50-75μm,the composite had the highest hardness,and the impact energy of the composites was the highest,which is 8 J.This was because there were more undissolved titanium carbide ceramics in the composite,and there was a thicker matrix metal between the ceramic particles.
基金supported by the National Natural Science Foundation of China(22076176,22276106)the Natural Science Foundation of Shandong Province(ZR2021YQ14)+3 种基金the Innovation Ability Improvement Project for Technology-based Small-and Medium-sized Enterprises of Shandong Province(2022TSGC1345)Jiangsu Province Science and Technology Plan Special Fund(BZ2022053)Key Research and Development Program of Anhui Province(202104g01020006)the Fundamental Research Funds for the Central Universities(202141008)。
文摘Catalyzed gasoline particulate filters(cGPFs)are being developed to enable compliance with the particulate number limits for passenger cars equipped with gasoline direct injection(GDI)engines in China and Europe,It is appealing to build catalysts with ceria—an irreplaceable"reducible"component in three-way converters—to help eliminate the soot particles trapped in cGPFs via O_(2)-assisted combustion.While research aiming at understanding how these recipes function has continued for more than two decades,a universal model elucidating the roles of different"active oxygen"species is yet to be realized.In this perspective,by critically assessing the reported data about gasoline soot catalytic combustion over ceria catalysts,it is suggested that ceria ignites soot through contributing its lattice oxygen,giving rise to a"hot ring"region at the periphery of soot-catalyst interface.During the"re-oxidation"semi-cycles,electrophilic superoxides and/or peroxides(O_(x)^(n-))are produced at the Ce^(3+)and oxygen vacancy sites enriched in this collar-like region,and then work as key reactive phases for soot deep oxidation.Based on this"O_(x)^(n-)assisted"Mars-van Krevelen mechanism,several guidelines for ceria catalyst designing are proposed,ending with a summary about where future opportunities and challenges may lie in developing efficient and practical cGPF catalysts.
基金supported by the National Natural Science Foundation of China(No.22176071)the Natural Science Foundation of Guangdong Province,China(No.2023A1515011879).
文摘Phthalate(PAEs)and Bisphenols(BPs)are plasticizers or additives in consumer products.They are typical endocrine disruptors,and potential health hazards may occur when people are exposed to them through inhalation,ingestion,and dermal contact.The current research on inhalation exposure pays limited attention to the particle distribution of PAEs and BPs in air,although particulate-bound pollutants are usually size-dependent.In this study,we discussed the size resolution of PAEs and BPs in air particles from city waste recycling plants.With paired urine samples of the workers,we also compared the internal and external exposure of PAEs and BPs and related potential health risks.The particulatebound PAEs and BPs concentrated mainly on coarse particles(Dp>2.1μm),with a bimodal distribution,and the peak particle size ranged from 9–10 to 4.7–5.85μm,respectively.Model calculation revealed that the deposition fluxes of PAEs in different respiratory regions followed the sequence of head airways(167±92.8 ng/h)>alveolar region(18.9±9.96 ng/h)>tracheobronchial region(9.20±5.22 ng/h),and the similar trends went for BPs.The daily intakes of PAEs and BPs via dust ingestion were higher than those fromrespiratory inhalation and dermal contact,with mean value of 96 and 0.88 ng/(kg-bw day),respectively.For internal exposure,the estimated daily intakes of PAEs for waste recycling workers were higher than those in e-waste dismantling workers,while the exposure levels of bisphenols were comparable.Overall,the potential health risks from inhalation exposure to particulate-bound PAEs and BPs were low.
基金supported by the Innovative Talent Project of Lanzhou City,Lanzhou Science and Technology Bureau(2022-RC-42)the Fundamental Research Funds for the Central Universities,Lanzhou University,China(lzujbky-2021-ey07,lzujbky-2024-it59,lzujbky-2025-it29)the Gansu Province Postgraduate Innovation Star Program(2025CXZX-018).
文摘Objective Chronic obstructive pulmonary disease(COPD)is a major health concern in northwest China;however,the impact of particulate matter(PM)exposure during sand-dust storms(SDS)remains poorly understood.Therefore,this study aimed to investigate the association between PM exposure on SDS days and COPD hospitalization risk in arid regions.Methods Data on daily COPD hospitalizations were collected from 323 hospitals from 2018 to 2022,along with the corresponding air pollutant and meteorological data for each city in Gansu Province.Employing a space-time-stratified case-crossover design and conditional Poisson regression,we analyzed 265,379 COPD hospitalizations.Results PM exposure during SDS days significantly increased COPD hospitalization risk[relative risk(RR)for PM2.5,lag 3:1.028,95%confidence interval(CI):1.021–1.034],particularly among men and the elderly,and during the cold season.The burden of PM exposure on COPD hospitalization was substantially high in Northwest China,especially in the arid and semi-arid regions.Conclusion Our findings revealed a positive correlation between PM exposure during SDS episodes and elevated hospitalization rates for COPD in arid and semi-arid zones in China.This highlights the urgency of developing region-specific public health strategies to address adverse respiratory outcomes associated with SDS-related air quality deterioration.
文摘Oxygenated fuels can reduce harmful emissions without affecting engine performance,meeting the big challenge in the transportation industry,which keeps the environment safe and reduces global warming.This study investigates the impact of biodiesel injection strategies and fuel injection pressures(FIP)on diesel engine exhaust emission characteristics.The engine is fuelled with 20%Jatropha biodiesel(JB)and 80%diesel,named JB20D.The ratios of fuel injection pressures started with injecting the fuel(diesel and JB20D)from 200 bar to 500 bar.The experimental outcomes indicate that the engine performance of brake-specific fuel consumption increased by 21.36%from the burning of JB20D compared with diesel,while brake thermal efficiency improved by 6.54%for low and high FIP compared to the diesel.The high fuel injection pressures slightly decrease the nitrogen oxide(NOX)emissions for both diesel and biodiesel.The emissions of NOX decreased from the combustion of JB20D by 18.7%under high fuel injection pressures compared to diesel.The concentration of soot particulate decreased by 20.4%form JB20D combustion than those combusted from diesel fuel.
