Rapid developments in the electronic information industry drive the increased energy usage and carbon emission of data center buildings,prompting the focus on the energy efficiency and environmental sustainability.Exp...Rapid developments in the electronic information industry drive the increased energy usage and carbon emission of data center buildings,prompting the focus on the energy efficiency and environmental sustainability.Expanded operation envelopes of tropical data centers is assessed to analyze the potential for the building energy savings and carbon emission reduction through collaborative analysis of operation modes(OMs),supply air temperature(SAT),and outdoor air temperature(OAT).The OMs of compression vary with the setpoints of SAT,in which the average exergy efficiency of compressors at alternate operation mode is 6.8%and 8.0%lower than that of double and single compression operations.As SAT rises from 20℃to 32℃,the system exergoeconomic factor increases from 5.4%to 8.0%,and the average carbon cost decreases by 36.5%.Additionally,with just an 8.5%increase in exergy cost(i.e.,Case 8)at OAT rising from 30 to 34℃,the high SAT and low refrigerant charges provide considerable exergy cost advantages versus resisting the OAT fluctuations.Dynamic operation strategies are also proposed and compared to cope with the impacts of tropical environments.Compared to the 26℃SAT baseline,the average energy savings are 9.1-14.7%,indicating the ability to fully utilize outdoor and indoor conditions.展开更多
Carbon-based air cathodes offer low cost,high electrical conductivity,and structural tunability.However,they suffer from limited catalytic activity and inefficient gas transport,and they typically rely on noble metal ...Carbon-based air cathodes offer low cost,high electrical conductivity,and structural tunability.However,they suffer from limited catalytic activity and inefficient gas transport,and they typically rely on noble metal additives or complex multilayer configurations.To tackle these issues,this study devised a self-activated integrated carbon-based air cathode.By integrating in situ catalytic site construction with structural optimization,the strategy not only induces the formation of oxygen functional groups(─C─OH,─C═O,─COOH),hierarchical pores,and uniformly distributed active sites,but also establishes a favorable electronic and mass-transport environment.Furthermore,the roll-pressing-based integrated design streamlines electrode construction,reinforces interfacial bonding,and significantly enhances mechanical stability.Density functional theory(DFT)calculations show that oxygen functional groups initiate hydrogen bonding interaction and promote charge enrichment,which improves the activity of the cathode and facilitates intermediate adsorption/desorption in oxygen reduction and evolution reactions processes.As a result,the integrated air cathode-based rechargeable zinc-air batteries(RZABs)achieve a high specific capacity of 811 mAh g^(-1).It also performs well in quasi-solid-state RZABs and silicon-air batteries systems across a wide temperature range,demonstrating strong adaptability and application potential.This study provides a scalable and cost-effective design strategy for high-performance carbon-based air cathodes,offering new insights into advancing durable and practical metal-air energy systems.展开更多
For hybrid-electric unmanned aerial vehicles(UAVs),the stable power supply from the onboard permanent magnet synchronous generator(PMSG)is critical.Overheating in the confined compartment can directly lead to power in...For hybrid-electric unmanned aerial vehicles(UAVs),the stable power supply from the onboard permanent magnet synchronous generator(PMSG)is critical.Overheating in the confined compartment can directly lead to power interruption and system failure.Therefore,proactively improving the thermal management is not only a key technical prerequisite for ensuring flight reliability and mission success,but also enhances the machine’s efficiency and the overall power density of the system.Targeting the stringent spatial constraints in UAV applications,novel self-air-cooling heat dissipation topologies are investigated and highlighted on the rotor sidewall for compact outer-rotor generators.A systematic optimization framework,centered on a multi-objective genetic algorithm,is developed to Pareto-optimize the fin geometries,balancing thermal performance against aerodynamic penalty.The proposed topologies are innovatively deployed on the rotor sidewall,uniquely combining the structural space of an outer-rotor machine with self-air-cooling to generate directed airflow of varying patterns that directly enhance the cooling efficiency of the stator.The parameters of the designed self-air-cooled heat dissipation topologies are optimized via a multi-objective genetic algorithm.A temperature rise test under windless conditions shows that the proposed self-air-cooled structure reduces the stator temperature of the generator by 37.1℃at 5000 r/min,confirming the effectiveness and engineering feasibility for practical applications.展开更多
The Mechanism for Air pollution compleX version 1.0(MAX1),describing detailed tropospheric chemical processes,has been developed based on the latest knowledge.MAX1 contains 940 reactions,including photolysis,gaseous r...The Mechanism for Air pollution compleX version 1.0(MAX1),describing detailed tropospheric chemical processes,has been developed based on the latest knowledge.MAX1 contains 940 reactions,including photolysis,gaseous reactions,and heterogeneous reactions of 300 species,which is adequate for both box model and climate transport model(CTM)applications.Detailed chemical processes of chlorine chemistry,chemistry of Criegee intermediates,and heterogeneous uptake of HO_(2) and N_(2)O_(5) have been implemented and updated.With this level of explicitness,MAX1 can support investigations into the quantification of secondary pollutant productions and the chemical behavior of the crucial intermediates,such as organic peroxy radicals.Box model and CTM tests were conducted to evaluate the performance of MAX1 from different perspectives.Simulations of MAX1 successfully captured the variation of ozone in all cases tested.Meanwhile,significant improvement was made on predictions of radicals compared to other mechanisms,especially under the low NO_(x) environment,with good similarity to simulations of a nearly explicit chemical mechanism(i.e.,Master Chemical Mechanism)that contains over 17000 reactions.The computational expense of MAX1 is acceptable and it can be applied in atmospheric scientific research and air quality prediction.MAX1 introduces new dimensions in atmospheric chemistry modeling,and its potential application in policymaking is a promising yet exploratory step.It offers improved insights into air quality dynamics,which could assist policymakers in making more informed decisions.However,the translation of its detailed chemical understanding into practical strategies remains an area for further investigation.This model suggests a path towards more nuanced air pollution control methods,contributing to ongoing efforts in environmental management.展开更多
Exposure to urban air pollution during early pregnancy is associated with increased risk for adverse pregnancy outcomes,such as preeclampsia(PE),and there is an urgent need to understand how air pollution affects biol...Exposure to urban air pollution during early pregnancy is associated with increased risk for adverse pregnancy outcomes,such as preeclampsia(PE),and there is an urgent need to understand how air pollution affects biological mechanisms in the placenta.Hofbauer cells(HBCs)are fetal placental macrophages that regulate immune tolerance in the placenta.They are normally polarized towards an anti-inflammatory M2 phenotype but display a more pro-inflammatory M1 phenotype in PE.The ex vivo dual placental perfusion approach uses full term human placentas to study physiological aspects of the placenta.In this study,effects of urban traffic-derived particles of size<2.5μm(PM_(2.5))on placental tissue and HBC polarization was deciphered.To study changes in placental microarchitecture and cell morphology,transmission electron microscopy was applied.In addition,changes in cell surface markers on HBCs were determined by immunohistochemistry.Exposure to PM_(2.5) caused disrupted collagen structures and affected cell organelles in multiple cell types inside placental villi.The resident HBC marker CD163 was not affected by PM_(2.5) exposure,while CD206 was reduced by 60%and CD209 remained unchanged,indicating altered M2 polarization.Additionally,the expression of pro-inflammatory M1 markers CD40(p=0.02)and CD80(p=0.03)in HBCs increased due to urban PM_(2.5) exposure.Urban PM_(2.5) showed detrimental effects on the placenta by disrupting tissue morphology and affecting HBC polarization specifically.These results extend the currently accepted view on properties of HBCs,by demonstrating their ability to react plastically and specifically to different exogenous stimuli.展开更多
Microorganisms constitute an essential component in the indoor environment,which is closely related to hu-man health.However,there is limited evidence regarding the associations between indoor airborne microbiome and ...Microorganisms constitute an essential component in the indoor environment,which is closely related to hu-man health.However,there is limited evidence regarding the associations between indoor airborne microbiome and systemic inflammation,as well as whether this association is modified by indoor particulate matter and the underlying mechanisms.In this prospective repeated-measure study among 66 participants,indoor airborne mi-crobiome was characterized using amplicon sequencing and qPCR.Indoor fine particulate matter(PM_(2.5))and inhalable particulate matter(PM10)were measured.Systemic inflammatory biomarkers were assessed,including white blood cell(WBC),neutrophil(NEUT),monocyte,eosinophil counts,and their proportions.Targeted serum amino acid metabolomics were conducted to explore the underlying mechanisms.Linear mixed-effect models re-vealed that bacterial and fungal Simpson diversity were significantly associated with decreased WBC and NEUT.For example,for each interquartile range increase in the bacterial Simpson diversity,WBC and NEUT changed by-4.53%(95%CI:-8.25%,-0.66%)and-5.95%(95%CI:-11.3%,-0.27%),respectively.Notably,increased inflammatory risks of airborne microbial exposure were observed when indoor PM_(2.5) and PM10 levels were below the WHO air quality guidelines.Mediation analyses indicated that dopamine metabolism partially mediated the anti-inflammatory effects of fungal diversity exposure.Overall,our study indicated protection from a diverse indoor microbial environment on cardiovascular health and proposed an underlying mechanism through amino acid metabolism.Additionally,health risks associated with microbial exposure deserve more attention in con-texts of low indoor particulate matter pollution.Further research is necessary to fully disentangle the complex relationships between indoor microbiome,air pollutants,and human health.展开更多
The issue of resistance reduction through hull ventilation is of particular interest in contemporary research.This paper presents multiphase computational fluid dynamics(CFD)simulations with 2-DOF motion of a planing ...The issue of resistance reduction through hull ventilation is of particular interest in contemporary research.This paper presents multiphase computational fluid dynamics(CFD)simulations with 2-DOF motion of a planing hull.The original hull was modified by introducing a step to allow air ventilation.Following an assessment of the hull performance,a simulation campaign in calm water was conducted to characterize the hull at various forward speeds and air insufflation rates for a defined single step geometry.Geometric analysis of the air layer thickness beneath the hull for each simulated condition was performed using a novel method for visualizing local air thickness.Additionally,two new parameters were introduced to understand the influence of spray rails on the air volume beneath the hull and to indicate the primary direction of ventilated air escape.A validation campaign and an assessment of uncertainty of the simulation has been conducted.The features offered by the CFD methodology include the evaluation of the air layer thickness as a function of hull velocity and injection flow rate and the air volume distribution beneath the hull.The air injection velocity can be adjusted across various operating conditions,thereby preventing performance or efficiency loss during navigation.Based on these findings,the study highlights the benefits of air insufflation in reducing hull resistance for high-speed planing vessels.This work lays a robust foundation for future research and new promising topics,as the exploration of air insufflation continues to be a topic of contemporary interest within naval architecture and hydrodynamics.展开更多
Previous modeling studies have made significant contributions to understanding the climatic effects of historical land use and land cover change(LULCC).However,the absence of transient land cover simulations may lead ...Previous modeling studies have made significant contributions to understanding the climatic effects of historical land use and land cover change(LULCC).However,the absence of transient land cover simulations may lead to uncertainties or inaccuracies in assessing their impacts.Further investigation of differences between fixed and transient LULCC simulations is needed.Here,we employ the Community Earth System Model(CESM)to analyze contrasting responses of mean and extreme near-surface air temperature to historical land cover change.Our results show that forest cover in Europe generally follows a linear upward trend,while East Asia experiences deforestation processes during the historical period.It is found that temperature changes do not exhibit similar seasonal variation and have regional dependence,with Europe showing more pronounced seasonal variability.It is also demonstrated that using fixed land cover simulations exaggerates the temperature responses,leading to an overestimation of temperatures.In Europe,the overestimation of mean and extreme near-surface air temperature is approximately 0.2℃ and 0.3℃,respectively.However,the overestimation is about 0.1℃ in East Asia.Besides,we further disentangle the local and nonlocal effects in the temperature changes and show that nonlocal atmospheric feedbacks dominate the temperature responses in Europe,while local and nonlocal effects exhibit similar temperature variations in East Asia.Further efforts to explore the nonlocal effects of realistic land cover change could help enhance our understanding of climatic effects of land cover change at midlatitudes.展开更多
With the rapid development of artificial intelligence,intelligent air combat maneuver decision-making(ACMD)has garnered global attention.Although deep reinforcement learning provides a promising approach to ACMD,exist...With the rapid development of artificial intelligence,intelligent air combat maneuver decision-making(ACMD)has garnered global attention.Although deep reinforcement learning provides a promising approach to ACMD,existing methods often suffer from rigid reward functions and limited adaptability to evolving adversarial strategies.Moreover,most research assumes open airspace,overlooking the influence of potential obstacles.In this paper,we address one-on-one within-visual-range ACMD in obstructed environments,and propose an improved Soft Actor-Critic(SAC)algorithm trained under a curriculum self-play framework.A maneuver strategy mirroring inference module is integrated to estimate each other's likely positions when visual obstruction occurs.By leveraging curriculum learning to guide progressive experience accumulation and self-play for adversarial evolution,our method enhances both training efficiency and tactical diversity.We further integrate an attention mechanism that dynamically adjusts the weights of sub-rewards,enabling the learned policy to adapt to rapidly changing air combat situations.Numerical simulations demonstrate that our enhanced SAC converges more quickly and achieves higher win rates than other baseline methods.An animation is available at bilibili.com/video/BV1BHVszHE98 for better illustration.展开更多
The utilisation of waste in green sustainable technology can provide a clean environment and support energy demand.This work aims to design and analyse the performance of a developed indirect flat-plate Solar Air Heat...The utilisation of waste in green sustainable technology can provide a clean environment and support energy demand.This work aims to design and analyse the performance of a developed indirect flat-plate Solar Air Heater(SAH)integrated with an internal thermal storage unit using Waste Automotive Oil(WAO).The SAH was designed based on the circulation of confined air around the internal thermal storage unit due to the updraft effects of hot air.Two SAHs were tested to compare the performance of WAO and water,with the results being compared to previous work that utilised phase change material.Results showed that WAO responds faster in the early stage,while water has slightly higher daytime efficiency,with a maximum temperature of 60℃,while WAO reached a maximum temperature of 76℃.During the discharge cycle,WAO achieved an efficiency of 65.7%,while the water’s efficiency 73.2% within the same period.The highest outlet air temperatures recorded were 43℃ for WAO and 33.8℃ for water.These findings support that water is suitable for applications requiring rapid thermal charging,while WAO offers extended thermal stability.The study highlights the feasibility of using low-cost materials,such as WAO and water,to enhance the performance of solar energy systems,thereby making them more viable for industrial applications like drying and heating.展开更多
Energy shortage has become one of themost concerning issues in the world today,and improving energy utilization efficiency is a key area of research for experts and scholars worldwide.Small-diameter heat exchangers of...Energy shortage has become one of themost concerning issues in the world today,and improving energy utilization efficiency is a key area of research for experts and scholars worldwide.Small-diameter heat exchangers offer advantages such as reduced material usage,lower refrigerant charge,and compact structure.However,they also face challenges,including increased refrigerant pressure drop and smaller heat transfer area inside the tubes.This paper combines the advantages and disadvantages of both small and large-diameter tubes and proposes a combined-diameter heat exchanger,consisting of large and small diameters,for use in the indoor units of split-type air conditioners.There are relatively few studies in this area.In this paper,A theoretical and numerical computation method is employed to establish a theoretical-numerical calculation model,and its reliability is verified through experiments.Using this model,the optimal combined diameters and flow path design for a combined-diameter heat exchanger using R32 as the working fluid are derived.The results show that the heat transfer performance of all combined diameter configurations improves by 2.79%to 8.26%compared to the baseline design,with the coefficient of performance(COP)increasing from 4.15 to 4.27~4.5.These designs can save copper material,but at the cost of an increase in pressure drop by 66.86%to 131.84%.The scheme IIIH,using R32,is the optimal combined-diameter and flow path configuration that balances both heat transfer performance and economic cost.展开更多
Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_...Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_(0.1)O_(3−δ)(BSCCFN)air electrode,based on Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)(BSCF),is designed using a perovskite A-B-site ionic Lewis acid strength(ISA)polarization distribution strategy and is successfully applied in both oxygen-ion conducting solid oxide fuel cells(O-SOFCs)and proton-conducting reversible protonic ceramic cells(R-PCCs).When BSCCFN is used as the air electrode in O-SOFCs,a peak power density(PPD)of 1.45 W cm^(−2)is achieved at 650°C,whereas in R-PCCs,a PPD of 1.13 W cm^(−2)and a current density of−1.8 A cm^(−2)at 1.3 V are achieved at the same temperature and show stable reversibility over 100 h.Experimental measurements and theoretical calculations demonstrate that low-ISA Cs+doping accelerates the reaction kinetics of both oxygen ions and protons,while high-ISA Nb^(5+)doping enhances electrode stability.The synergistic effect of Cs^(+)and Nb^(5+)co-doping in the BSCCFN electrode lies in the ISA polarization distribution,which weakens the Co/Fe–O bond covalency,thereby promoting oxygen vacancy formation and facilitating the conduction of oxygen ions and protons.展开更多
To address the severe challenges of PM_(2.5) and ozone co-control during the"14^(th) Five-Year Plan"period and to enhance the precision and intelligence level of air environment governance,it is imperative t...To address the severe challenges of PM_(2.5) and ozone co-control during the"14^(th) Five-Year Plan"period and to enhance the precision and intelligence level of air environment governance,it is imperative to build an efficient comprehensive management platform for regional air quality.In this paper,the specific practice in Zibo City,Shandong Province is as an example to systematically analyze the top-level design,technical implementation,and innovative application of a comprehensive management platform for regional air quality integrating"perception monitoring,data fusion,research judgment of early warnings,analysis of sources,collaborative dispatching,and evaluation assessment".Through the construction of an"sky-air-ground"integrated three-dimensional monitoring network,the platform integrates multi-source heterogeneous environmental data,and employs big data,cloud computing,artificial intelligence,CALPUFF/CMAQ,and other numerical model technologies to achieve comprehensive perception,precise prediction,intelligent source tracing,and closed-loop management of air pollution.The platform innovatively establishes a full-process closed-loop management mechanism of"data-early warning-disposition-evaluation",and achieves a fundamental transformation from passive response to active anticipation and from experience-based judgment to data driving in environmental supervision.The application results show that this platform significantly improves the scientific decision-making ability and collaborative execution efficiency of air pollution governance in Zibo City,providing a replicable and scalable comprehensive solution for similar industrial cities to achieve the continuous improvement of air quality.展开更多
Efficient photocatalytic reduction of CO_(2)is crucial to decrease the atmospheric concentration of CO_(2).Pairing this process with H_(2)O_(2)production is of considerable importance for simultaneously producing valu...Efficient photocatalytic reduction of CO_(2)is crucial to decrease the atmospheric concentration of CO_(2).Pairing this process with H_(2)O_(2)production is of considerable importance for simultaneously producing value-added chemicals.However,the photocatalysts reported for such a process suffer from a high recombination rate of the surface/bulk charges,as well as inefficient enrichment and activation toward CO_(2)and O_(2),resulting in low conversion efficiency even in the presence of organic sacrificial agents and expensive metal co-catalysts.Herein,two 1,3,5-triphenylbenzene-based organic polymers with high ionic density and porosity are prepared through a facile Sonogashira polymerization.The ionic imidazolium sites embedded in the polymeric skeleton provide the two polymers(iCMP-1 and iCMP-2)with adsorptive selectivity for CO_(2)/N_(2) up to 98-102 at 273 K,facilitating the enrichment of CO_(2)and O_(2)molecules around the catalytic centers,thus boosting their catalytic conversion directly from air under solar light(100 mW cm^(-2)).Benefiting from the improved charge separation and broad light absorption,along with high CO_(2)and O_(2)uptake,iCMP-2 can deliver excellent CO and H_(2)O_(2)yields(611.8 and 810.6μmol h^(-1)g^(-1),respectively)under an atmosphere composed of water vapor and air without any co-catalysts.展开更多
The Yangtze River Delta(YRD)is one of China’s most economically dense regions with the most dynamic county-level economies.The YRD’s success in addressing air pollution at the county level directly affects the ecolo...The Yangtze River Delta(YRD)is one of China’s most economically dense regions with the most dynamic county-level economies.The YRD’s success in addressing air pollution at the county level directly affects the ecological security of the Yangtze River Economic Belt.This study utilizes panel data of 151 counties in the YRD from 2003 to 2022.It regards the expansion of members of the YRD Urban Economic Coordination Council as a quasi-natural experiment.This study analyzes the influence of regional integration on county-level air pollution using the difference-in-differences approach,the synthetic difference-in-differences methodology,and spatial econometrics.Our findings indicate that:(1)regional integration can significantly reduce air pollution at the county level;(2)the environmental impact of regional integration is heterogeneous,influenced by regional differences,administrative constraints,and industrial foundations;and(3)regional integration reduces air pollution through advancing industrial structure and technological innovation,along with spatial spillover impacts.Therefore,policymakers should attach importance to air quality governance in counties,deepen regional integration strategies,optimize industrial structures,enhance technological innovation,and strengthen collaborative environmental governance to continuously promote regional sustainable development.展开更多
Ce and its oxide(CeO_(2))have garnered extensive research attention in catalytic elimination of various air pollutants owing to their superior redox performance and oxygen storage capacity,which might originate from t...Ce and its oxide(CeO_(2))have garnered extensive research attention in catalytic elimination of various air pollutants owing to their superior redox performance and oxygen storage capacity,which might originate from the overlap of Ce 4f-5d atomic orbitals,as depicted in Cotton atomic orbital energy level diagram.To further tap the potential of CeO_(2),strategic integration with diverse transition metals and noble metals has been implemented.The distinctive nature of Cu in forming strong interactions with CeO_(2),coupled with its economic viability,has propelled substantial investigations into CuO-CeO_(2)composite catalysts for air pollutant removal.In this review,starting from a discussion on the classical dispersion model of Cu on CeO_(2),the current development in the synthesis and characterization of CuOCeO_(2) catalysts is systematically summarized.Subsequently,the application of CuO-CeO_(2) catalysts in several common air pollutant elimination-related reactions(e.g.,CO oxidation,NO reduction by CO,NH_(3)-SCR and NH_(3)-SCO)is discussed in depth.The review can provide significant guidance for the rational engineering of high-efficiency CuO-CeO_(2) catalysts.展开更多
Existing evidence suggests residential greenness is beneficial to human,while no research to date explored the associations of greenness with age-related macular degeneration(AMD).To evaluate the association of greenn...Existing evidence suggests residential greenness is beneficial to human,while no research to date explored the associations of greenness with age-related macular degeneration(AMD).To evaluate the association of greenness with AMD,modification and mediation effect of air pollution,we conducted this prospective study.We con-structed weighted quantile sum(WQS)index as co-exposure to nitrogen oxides(NO_(x)),particulate matter<2.5μm(PM_(2.5)),particulate matter<10μm(PM10).Stratified Cox regression models were applied to test the effect of exposure.Effect modification of air pollution was assessed.Stratified Cox models through the indirect method and Aalen additive risk models were used in mediation analysis.Over median follow-up of 11.67 years,4596 AMD events were ascertained.Hazard ratios(HRs)and 95%confidence intervals(95%CIs)of incident AMD for pollution per interquartile range(IQR)increment were 1.10(1.04–1.16)for nitrogen dioxide(NO_(2)),1.09(1.03–1.15)for NO_(x),1.14(1.05–1.24)for PM_(2.5),1.13(1.05–1.21)for PM10.The HR(95%CI)of AMD associated with greenness 1000 m buffer per IQR increment was 0.91(0.86–0.97),300 m buffer was 0.94(0.89–0.99).The as-sociation between greenness 1000 m and AMD was 28.59%,44.77%,35.59%,32.31%and 27.08%mediated by the decreased WQS index,NO_(2),NO_(x),PM_(2.5) and PM10,respectively.Increased greenness was associated with lower AMD incidence,and air pollution partly mediate it,which implies that interventions aimed at improving air quality and increasing greenness could have a dual benefit in mitigating AMD risk.展开更多
Perception of air pollution is subjective and context-dependent.Previous studies exploring the association between measured air pollution and perceived air quality mainly focused on air pollution levels measured in th...Perception of air pollution is subjective and context-dependent.Previous studies exploring the association between measured air pollution and perceived air quality mainly focused on air pollution levels measured in the residence-based(RB)or regional context,overlooking the mobility-based(MB)context in which people are exposed to air pollution.This study measures air pollution levels in MB,RB,and regional contexts and examines their relationships with perceived air quality across different neighborhoods and gender sub-groups of Hong Kong,China to investigate how people perceive air quality.The results indicate that particulate matter 2.5(PM_(2.5))measured in RB and the regional context significantly contributes to people’s perceived air quality compared to MB PM_(2.5).Individuals in Central and Western district of Hong Kong rely on RB,regional and MB PM_(2.5) to assess air pollution.In Sham Shui Po,RB PM_(2.5) exhibits the highest influence on people’s perceived air quality,followed by regional PM_(2.5).Women’s perceived air quality is strongly related to their RB PM_(2.5) exposure,while men’s perceived air quality is associated with both RB PM_(2.5) and regional PM_(2.5) levels.We conclude that neighborhood effects and mobility levels are the two most important factors influencing the association between meas-ured air pollution and perceived air quality.We reveal that the neighborhood effect averaging problem(NEAP)influences the associ-ation between perceived air quality and measured air pollution levels in a way that differs from health outcome-related studies.Effect-ive measures are needed to improve the public’s awareness of air pollution,and scientific control should be implemented to reduce pub-lic exposure.展开更多
The rapid expansion of the low-altitude economy is driving strong demand for highly accurate and reliable positioning technologies to support diverse aerial operations.This review examines core positioning methodologi...The rapid expansion of the low-altitude economy is driving strong demand for highly accurate and reliable positioning technologies to support diverse aerial operations.This review examines core positioning methodologies within the low-altitude intelligent network(LAIN)framework,beginning with an analysis of positioning requirements and performance metrics for low-altitude flight scenarios.It systematically assesses the principles,strengths,and limitations of mainstream positioning systems,including Global Navigation Satellite Systems(GNSS),terrestrial wireless positioning,and autonomous navigation,and it surveys prevalent integrated and cooperative positioning schemes.Our analysis demonstrates that standalone positioning technologies are inadequate in complex low-altitude settings,underscoring the pivotal role of multi-source fusion and unmanned aerial vehicle(UAV)swarm cooperative positioning as future trends.To address infrastructure gaps and high deployment costs in current LAIN systems,we propose a“space−air−ground”integrated and cooperative positioning architecture centered on GNSS and the 5th generation mobile communication technology(5G).The ground layer integrates 5G and GNSS for wide-area enhanced positioning.The aerial layer uses 5G aircraft-to-everything(A2X)and sidelink(SL)communications to build self-organizing networks for cooperative UAV localization.The space layer leverages low Earth orbit(LEO)satellites to overcome coverage limitations in communication and positioning.This hierarchical architecture reduces deployment costs through infrastructure reuse and enables deep integration of communication and navigation capabilities.By supporting collaborative enhancement across all three domains,the framework improves positioning robustness and delivers cost-effective,ubiquitous,and highly reliable positioning services.Finally,we outline promising research directions.This review aims to provide a systematic reference and a novel architectural perspective for the ongoing development of LAIN.展开更多
基金supported by the National Research Foundation,Singapore,funded under Energy Research Testbed and Industry Partnership Funding Initiative,part of the Energy Grid(EG)2.0 programme.
文摘Rapid developments in the electronic information industry drive the increased energy usage and carbon emission of data center buildings,prompting the focus on the energy efficiency and environmental sustainability.Expanded operation envelopes of tropical data centers is assessed to analyze the potential for the building energy savings and carbon emission reduction through collaborative analysis of operation modes(OMs),supply air temperature(SAT),and outdoor air temperature(OAT).The OMs of compression vary with the setpoints of SAT,in which the average exergy efficiency of compressors at alternate operation mode is 6.8%and 8.0%lower than that of double and single compression operations.As SAT rises from 20℃to 32℃,the system exergoeconomic factor increases from 5.4%to 8.0%,and the average carbon cost decreases by 36.5%.Additionally,with just an 8.5%increase in exergy cost(i.e.,Case 8)at OAT rising from 30 to 34℃,the high SAT and low refrigerant charges provide considerable exergy cost advantages versus resisting the OAT fluctuations.Dynamic operation strategies are also proposed and compared to cope with the impacts of tropical environments.Compared to the 26℃SAT baseline,the average energy savings are 9.1-14.7%,indicating the ability to fully utilize outdoor and indoor conditions.
基金funded by the National Nature Science Foundation of China(62264006,62574102)“Thousand Talents Program”of Yunnan Province for Young Talents,Innovative Research Teams(in Science and Technology)in the University of Yunnan Province(IRTSTYN),XingDian Talent Support Program for Young Talents,and Frontier Research Team of Kunming University 2023,The Basic Research Project of Yunnan Province(Nos.202201AU070022)+2 种基金Kunming University Talent Introduction Fund(Nos.YJL20024)Yunnan Province Education Department Scientific Research Fund Project(Nos.2024Y759)Undergraduate Innovation and Entrepreneurship Training Program Project of Yunnan Provincial(202411393005)。
文摘Carbon-based air cathodes offer low cost,high electrical conductivity,and structural tunability.However,they suffer from limited catalytic activity and inefficient gas transport,and they typically rely on noble metal additives or complex multilayer configurations.To tackle these issues,this study devised a self-activated integrated carbon-based air cathode.By integrating in situ catalytic site construction with structural optimization,the strategy not only induces the formation of oxygen functional groups(─C─OH,─C═O,─COOH),hierarchical pores,and uniformly distributed active sites,but also establishes a favorable electronic and mass-transport environment.Furthermore,the roll-pressing-based integrated design streamlines electrode construction,reinforces interfacial bonding,and significantly enhances mechanical stability.Density functional theory(DFT)calculations show that oxygen functional groups initiate hydrogen bonding interaction and promote charge enrichment,which improves the activity of the cathode and facilitates intermediate adsorption/desorption in oxygen reduction and evolution reactions processes.As a result,the integrated air cathode-based rechargeable zinc-air batteries(RZABs)achieve a high specific capacity of 811 mAh g^(-1).It also performs well in quasi-solid-state RZABs and silicon-air batteries systems across a wide temperature range,demonstrating strong adaptability and application potential.This study provides a scalable and cost-effective design strategy for high-performance carbon-based air cathodes,offering new insights into advancing durable and practical metal-air energy systems.
基金supported in part by the State Key Laboratory of Robotics and System under Grant SKLRS202407B.
文摘For hybrid-electric unmanned aerial vehicles(UAVs),the stable power supply from the onboard permanent magnet synchronous generator(PMSG)is critical.Overheating in the confined compartment can directly lead to power interruption and system failure.Therefore,proactively improving the thermal management is not only a key technical prerequisite for ensuring flight reliability and mission success,but also enhances the machine’s efficiency and the overall power density of the system.Targeting the stringent spatial constraints in UAV applications,novel self-air-cooling heat dissipation topologies are investigated and highlighted on the rotor sidewall for compact outer-rotor generators.A systematic optimization framework,centered on a multi-objective genetic algorithm,is developed to Pareto-optimize the fin geometries,balancing thermal performance against aerodynamic penalty.The proposed topologies are innovatively deployed on the rotor sidewall,uniquely combining the structural space of an outer-rotor machine with self-air-cooling to generate directed airflow of varying patterns that directly enhance the cooling efficiency of the stator.The parameters of the designed self-air-cooled heat dissipation topologies are optimized via a multi-objective genetic algorithm.A temperature rise test under windless conditions shows that the proposed self-air-cooled structure reduces the stator temperature of the generator by 37.1℃at 5000 r/min,confirming the effectiveness and engineering feasibility for practical applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.22325601,92044302,42377105)the National Key Scientific and Technological Infrastructure project“Earth System Science Numerical Simulator Facility”.
文摘The Mechanism for Air pollution compleX version 1.0(MAX1),describing detailed tropospheric chemical processes,has been developed based on the latest knowledge.MAX1 contains 940 reactions,including photolysis,gaseous reactions,and heterogeneous reactions of 300 species,which is adequate for both box model and climate transport model(CTM)applications.Detailed chemical processes of chlorine chemistry,chemistry of Criegee intermediates,and heterogeneous uptake of HO_(2) and N_(2)O_(5) have been implemented and updated.With this level of explicitness,MAX1 can support investigations into the quantification of secondary pollutant productions and the chemical behavior of the crucial intermediates,such as organic peroxy radicals.Box model and CTM tests were conducted to evaluate the performance of MAX1 from different perspectives.Simulations of MAX1 successfully captured the variation of ozone in all cases tested.Meanwhile,significant improvement was made on predictions of radicals compared to other mechanisms,especially under the low NO_(x) environment,with good similarity to simulations of a nearly explicit chemical mechanism(i.e.,Master Chemical Mechanism)that contains over 17000 reactions.The computational expense of MAX1 is acceptable and it can be applied in atmospheric scientific research and air quality prediction.MAX1 introduces new dimensions in atmospheric chemistry modeling,and its potential application in policymaking is a promising yet exploratory step.It offers improved insights into air quality dynamics,which could assist policymakers in making more informed decisions.However,the translation of its detailed chemical understanding into practical strategies remains an area for further investigation.This model suggests a path towards more nuanced air pollution control methods,contributing to ongoing efforts in environmental management.
基金supported by The Swedish Research Council(Vetenskapsrådet,No.314373.35.135949)ALF+3 种基金SUS FoundationRegion Skånes Foundations in Swedensupported through the PhD program Inflammatory Disorders in Pregnancy(DP-iDP)by the Austrian Science Fund FWF(No.Doc 31-B26)the Medical University of Graz,Austria.
文摘Exposure to urban air pollution during early pregnancy is associated with increased risk for adverse pregnancy outcomes,such as preeclampsia(PE),and there is an urgent need to understand how air pollution affects biological mechanisms in the placenta.Hofbauer cells(HBCs)are fetal placental macrophages that regulate immune tolerance in the placenta.They are normally polarized towards an anti-inflammatory M2 phenotype but display a more pro-inflammatory M1 phenotype in PE.The ex vivo dual placental perfusion approach uses full term human placentas to study physiological aspects of the placenta.In this study,effects of urban traffic-derived particles of size<2.5μm(PM_(2.5))on placental tissue and HBC polarization was deciphered.To study changes in placental microarchitecture and cell morphology,transmission electron microscopy was applied.In addition,changes in cell surface markers on HBCs were determined by immunohistochemistry.Exposure to PM_(2.5) caused disrupted collagen structures and affected cell organelles in multiple cell types inside placental villi.The resident HBC marker CD163 was not affected by PM_(2.5) exposure,while CD206 was reduced by 60%and CD209 remained unchanged,indicating altered M2 polarization.Additionally,the expression of pro-inflammatory M1 markers CD40(p=0.02)and CD80(p=0.03)in HBCs increased due to urban PM_(2.5) exposure.Urban PM_(2.5) showed detrimental effects on the placenta by disrupting tissue morphology and affecting HBC polarization specifically.These results extend the currently accepted view on properties of HBCs,by demonstrating their ability to react plastically and specifically to different exogenous stimuli.
基金supported by the National Key Research and Development Program of China(No.2022YFC3702704)the National Natural Science Foundation of China(Nos.22376005,22076006 and 82073506).
文摘Microorganisms constitute an essential component in the indoor environment,which is closely related to hu-man health.However,there is limited evidence regarding the associations between indoor airborne microbiome and systemic inflammation,as well as whether this association is modified by indoor particulate matter and the underlying mechanisms.In this prospective repeated-measure study among 66 participants,indoor airborne mi-crobiome was characterized using amplicon sequencing and qPCR.Indoor fine particulate matter(PM_(2.5))and inhalable particulate matter(PM10)were measured.Systemic inflammatory biomarkers were assessed,including white blood cell(WBC),neutrophil(NEUT),monocyte,eosinophil counts,and their proportions.Targeted serum amino acid metabolomics were conducted to explore the underlying mechanisms.Linear mixed-effect models re-vealed that bacterial and fungal Simpson diversity were significantly associated with decreased WBC and NEUT.For example,for each interquartile range increase in the bacterial Simpson diversity,WBC and NEUT changed by-4.53%(95%CI:-8.25%,-0.66%)and-5.95%(95%CI:-11.3%,-0.27%),respectively.Notably,increased inflammatory risks of airborne microbial exposure were observed when indoor PM_(2.5) and PM10 levels were below the WHO air quality guidelines.Mediation analyses indicated that dopamine metabolism partially mediated the anti-inflammatory effects of fungal diversity exposure.Overall,our study indicated protection from a diverse indoor microbial environment on cardiovascular health and proposed an underlying mechanism through amino acid metabolism.Additionally,health risks associated with microbial exposure deserve more attention in con-texts of low indoor particulate matter pollution.Further research is necessary to fully disentangle the complex relationships between indoor microbiome,air pollutants,and human health.
基金supported by European Union funding(PON“Ricerca e Innovazione”2014‒2020).
文摘The issue of resistance reduction through hull ventilation is of particular interest in contemporary research.This paper presents multiphase computational fluid dynamics(CFD)simulations with 2-DOF motion of a planing hull.The original hull was modified by introducing a step to allow air ventilation.Following an assessment of the hull performance,a simulation campaign in calm water was conducted to characterize the hull at various forward speeds and air insufflation rates for a defined single step geometry.Geometric analysis of the air layer thickness beneath the hull for each simulated condition was performed using a novel method for visualizing local air thickness.Additionally,two new parameters were introduced to understand the influence of spray rails on the air volume beneath the hull and to indicate the primary direction of ventilated air escape.A validation campaign and an assessment of uncertainty of the simulation has been conducted.The features offered by the CFD methodology include the evaluation of the air layer thickness as a function of hull velocity and injection flow rate and the air volume distribution beneath the hull.The air injection velocity can be adjusted across various operating conditions,thereby preventing performance or efficiency loss during navigation.Based on these findings,the study highlights the benefits of air insufflation in reducing hull resistance for high-speed planing vessels.This work lays a robust foundation for future research and new promising topics,as the exploration of air insufflation continues to be a topic of contemporary interest within naval architecture and hydrodynamics.
基金supported by the National Key R&D Program of China(Grant No.2022YFF0801601).
文摘Previous modeling studies have made significant contributions to understanding the climatic effects of historical land use and land cover change(LULCC).However,the absence of transient land cover simulations may lead to uncertainties or inaccuracies in assessing their impacts.Further investigation of differences between fixed and transient LULCC simulations is needed.Here,we employ the Community Earth System Model(CESM)to analyze contrasting responses of mean and extreme near-surface air temperature to historical land cover change.Our results show that forest cover in Europe generally follows a linear upward trend,while East Asia experiences deforestation processes during the historical period.It is found that temperature changes do not exhibit similar seasonal variation and have regional dependence,with Europe showing more pronounced seasonal variability.It is also demonstrated that using fixed land cover simulations exaggerates the temperature responses,leading to an overestimation of temperatures.In Europe,the overestimation of mean and extreme near-surface air temperature is approximately 0.2℃ and 0.3℃,respectively.However,the overestimation is about 0.1℃ in East Asia.Besides,we further disentangle the local and nonlocal effects in the temperature changes and show that nonlocal atmospheric feedbacks dominate the temperature responses in Europe,while local and nonlocal effects exhibit similar temperature variations in East Asia.Further efforts to explore the nonlocal effects of realistic land cover change could help enhance our understanding of climatic effects of land cover change at midlatitudes.
基金support of the National Key Research and Development Plan(No.2021YFB3302501)the financial support of the National Science Foundation of China(No.12161076)the financial support of the Fundamental Research Funds for the Central Universities(No.DUT25GF207).
文摘With the rapid development of artificial intelligence,intelligent air combat maneuver decision-making(ACMD)has garnered global attention.Although deep reinforcement learning provides a promising approach to ACMD,existing methods often suffer from rigid reward functions and limited adaptability to evolving adversarial strategies.Moreover,most research assumes open airspace,overlooking the influence of potential obstacles.In this paper,we address one-on-one within-visual-range ACMD in obstructed environments,and propose an improved Soft Actor-Critic(SAC)algorithm trained under a curriculum self-play framework.A maneuver strategy mirroring inference module is integrated to estimate each other's likely positions when visual obstruction occurs.By leveraging curriculum learning to guide progressive experience accumulation and self-play for adversarial evolution,our method enhances both training efficiency and tactical diversity.We further integrate an attention mechanism that dynamically adjusts the weights of sub-rewards,enabling the learned policy to adapt to rapidly changing air combat situations.Numerical simulations demonstrate that our enhanced SAC converges more quickly and achieves higher win rates than other baseline methods.An animation is available at bilibili.com/video/BV1BHVszHE98 for better illustration.
文摘The utilisation of waste in green sustainable technology can provide a clean environment and support energy demand.This work aims to design and analyse the performance of a developed indirect flat-plate Solar Air Heater(SAH)integrated with an internal thermal storage unit using Waste Automotive Oil(WAO).The SAH was designed based on the circulation of confined air around the internal thermal storage unit due to the updraft effects of hot air.Two SAHs were tested to compare the performance of WAO and water,with the results being compared to previous work that utilised phase change material.Results showed that WAO responds faster in the early stage,while water has slightly higher daytime efficiency,with a maximum temperature of 60℃,while WAO reached a maximum temperature of 76℃.During the discharge cycle,WAO achieved an efficiency of 65.7%,while the water’s efficiency 73.2% within the same period.The highest outlet air temperatures recorded were 43℃ for WAO and 33.8℃ for water.These findings support that water is suitable for applications requiring rapid thermal charging,while WAO offers extended thermal stability.The study highlights the feasibility of using low-cost materials,such as WAO and water,to enhance the performance of solar energy systems,thereby making them more viable for industrial applications like drying and heating.
基金supported by Supported by the Scientific Research Foundation for High-Level Talents of Zhoukou Normal University(ZKNUC2024018).
文摘Energy shortage has become one of themost concerning issues in the world today,and improving energy utilization efficiency is a key area of research for experts and scholars worldwide.Small-diameter heat exchangers offer advantages such as reduced material usage,lower refrigerant charge,and compact structure.However,they also face challenges,including increased refrigerant pressure drop and smaller heat transfer area inside the tubes.This paper combines the advantages and disadvantages of both small and large-diameter tubes and proposes a combined-diameter heat exchanger,consisting of large and small diameters,for use in the indoor units of split-type air conditioners.There are relatively few studies in this area.In this paper,A theoretical and numerical computation method is employed to establish a theoretical-numerical calculation model,and its reliability is verified through experiments.Using this model,the optimal combined diameters and flow path design for a combined-diameter heat exchanger using R32 as the working fluid are derived.The results show that the heat transfer performance of all combined diameter configurations improves by 2.79%to 8.26%compared to the baseline design,with the coefficient of performance(COP)increasing from 4.15 to 4.27~4.5.These designs can save copper material,but at the cost of an increase in pressure drop by 66.86%to 131.84%.The scheme IIIH,using R32,is the optimal combined-diameter and flow path configuration that balances both heat transfer performance and economic cost.
基金funding from the National Natural Science Foundation of China (Award 91745203) supplemented by Central Universities’ Basic Research Funds.
文摘Ceramic cells promise ideal energy conversion and storage devices,making the development of efficient and robust air electrodes crucial for their application.In this study,a Ba_(0.4)Sr_(0.5)Cs_(0.1)Co_(0.7)Fe_(0.2)Nb_(0.1)O_(3−δ)(BSCCFN)air electrode,based on Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3−δ)(BSCF),is designed using a perovskite A-B-site ionic Lewis acid strength(ISA)polarization distribution strategy and is successfully applied in both oxygen-ion conducting solid oxide fuel cells(O-SOFCs)and proton-conducting reversible protonic ceramic cells(R-PCCs).When BSCCFN is used as the air electrode in O-SOFCs,a peak power density(PPD)of 1.45 W cm^(−2)is achieved at 650°C,whereas in R-PCCs,a PPD of 1.13 W cm^(−2)and a current density of−1.8 A cm^(−2)at 1.3 V are achieved at the same temperature and show stable reversibility over 100 h.Experimental measurements and theoretical calculations demonstrate that low-ISA Cs+doping accelerates the reaction kinetics of both oxygen ions and protons,while high-ISA Nb^(5+)doping enhances electrode stability.The synergistic effect of Cs^(+)and Nb^(5+)co-doping in the BSCCFN electrode lies in the ISA polarization distribution,which weakens the Co/Fe–O bond covalency,thereby promoting oxygen vacancy formation and facilitating the conduction of oxygen ions and protons.
文摘To address the severe challenges of PM_(2.5) and ozone co-control during the"14^(th) Five-Year Plan"period and to enhance the precision and intelligence level of air environment governance,it is imperative to build an efficient comprehensive management platform for regional air quality.In this paper,the specific practice in Zibo City,Shandong Province is as an example to systematically analyze the top-level design,technical implementation,and innovative application of a comprehensive management platform for regional air quality integrating"perception monitoring,data fusion,research judgment of early warnings,analysis of sources,collaborative dispatching,and evaluation assessment".Through the construction of an"sky-air-ground"integrated three-dimensional monitoring network,the platform integrates multi-source heterogeneous environmental data,and employs big data,cloud computing,artificial intelligence,CALPUFF/CMAQ,and other numerical model technologies to achieve comprehensive perception,precise prediction,intelligent source tracing,and closed-loop management of air pollution.The platform innovatively establishes a full-process closed-loop management mechanism of"data-early warning-disposition-evaluation",and achieves a fundamental transformation from passive response to active anticipation and from experience-based judgment to data driving in environmental supervision.The application results show that this platform significantly improves the scientific decision-making ability and collaborative execution efficiency of air pollution governance in Zibo City,providing a replicable and scalable comprehensive solution for similar industrial cities to achieve the continuous improvement of air quality.
基金supported by the Excellent Youth Foundation of Jiangxi Scientific Committee(no.20232ACB213012)National Science Foundation of Jiangxi Province of China(no.20242BAB25236)+2 种基金Jiangxi Talent Program(no.DHSQT32022005)Beijing Institute of Technology Research Fund Program for Young Scholars(XSQD-202215006)National Natural Science Foundation of China(no.22202008 and 22202039).
文摘Efficient photocatalytic reduction of CO_(2)is crucial to decrease the atmospheric concentration of CO_(2).Pairing this process with H_(2)O_(2)production is of considerable importance for simultaneously producing value-added chemicals.However,the photocatalysts reported for such a process suffer from a high recombination rate of the surface/bulk charges,as well as inefficient enrichment and activation toward CO_(2)and O_(2),resulting in low conversion efficiency even in the presence of organic sacrificial agents and expensive metal co-catalysts.Herein,two 1,3,5-triphenylbenzene-based organic polymers with high ionic density and porosity are prepared through a facile Sonogashira polymerization.The ionic imidazolium sites embedded in the polymeric skeleton provide the two polymers(iCMP-1 and iCMP-2)with adsorptive selectivity for CO_(2)/N_(2) up to 98-102 at 273 K,facilitating the enrichment of CO_(2)and O_(2)molecules around the catalytic centers,thus boosting their catalytic conversion directly from air under solar light(100 mW cm^(-2)).Benefiting from the improved charge separation and broad light absorption,along with high CO_(2)and O_(2)uptake,iCMP-2 can deliver excellent CO and H_(2)O_(2)yields(611.8 and 810.6μmol h^(-1)g^(-1),respectively)under an atmosphere composed of water vapor and air without any co-catalysts.
基金sponsored by Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project[Grant No.2024ZD1002001]National Social Science Foundation of China[Grant No.24VHQ005],National Natural Science Foundation of China[Grant No.72403050]the Fundamental Research Funds for the Central Universities[Grant No.2-9-2023-039].
文摘The Yangtze River Delta(YRD)is one of China’s most economically dense regions with the most dynamic county-level economies.The YRD’s success in addressing air pollution at the county level directly affects the ecological security of the Yangtze River Economic Belt.This study utilizes panel data of 151 counties in the YRD from 2003 to 2022.It regards the expansion of members of the YRD Urban Economic Coordination Council as a quasi-natural experiment.This study analyzes the influence of regional integration on county-level air pollution using the difference-in-differences approach,the synthetic difference-in-differences methodology,and spatial econometrics.Our findings indicate that:(1)regional integration can significantly reduce air pollution at the county level;(2)the environmental impact of regional integration is heterogeneous,influenced by regional differences,administrative constraints,and industrial foundations;and(3)regional integration reduces air pollution through advancing industrial structure and technological innovation,along with spatial spillover impacts.Therefore,policymakers should attach importance to air quality governance in counties,deepen regional integration strategies,optimize industrial structures,enhance technological innovation,and strengthen collaborative environmental governance to continuously promote regional sustainable development.
基金Project supported by the National Natural Science Foundation of China(22306090,22272077,22402027)the Natural Science Foundation of Jiangsu Province(BK20230773,BK20231513)+1 种基金the Young Elite Scientists Sponsorship Program by CAST(YESS20230298)the Sinopec Group(H25007)。
文摘Ce and its oxide(CeO_(2))have garnered extensive research attention in catalytic elimination of various air pollutants owing to their superior redox performance and oxygen storage capacity,which might originate from the overlap of Ce 4f-5d atomic orbitals,as depicted in Cotton atomic orbital energy level diagram.To further tap the potential of CeO_(2),strategic integration with diverse transition metals and noble metals has been implemented.The distinctive nature of Cu in forming strong interactions with CeO_(2),coupled with its economic viability,has propelled substantial investigations into CuO-CeO_(2)composite catalysts for air pollutant removal.In this review,starting from a discussion on the classical dispersion model of Cu on CeO_(2),the current development in the synthesis and characterization of CuOCeO_(2) catalysts is systematically summarized.Subsequently,the application of CuO-CeO_(2) catalysts in several common air pollutant elimination-related reactions(e.g.,CO oxidation,NO reduction by CO,NH_(3)-SCR and NH_(3)-SCO)is discussed in depth.The review can provide significant guidance for the rational engineering of high-efficiency CuO-CeO_(2) catalysts.
基金supported by the High-level Talents Introduction Plan from Central South University(No.502045003)the National Natural Science Foundation of China(No.42277438)Hunan Provincial Natural Science Foundation for Distinguished Young Scholars(No.2024JJ2082)to Fang Xiao,and the Postgraduate Independent Exploration and Innovation Project of Central South University,China(Nos.2024ZZTS0557 and 2023ZZTS0993)。
文摘Existing evidence suggests residential greenness is beneficial to human,while no research to date explored the associations of greenness with age-related macular degeneration(AMD).To evaluate the association of greenness with AMD,modification and mediation effect of air pollution,we conducted this prospective study.We con-structed weighted quantile sum(WQS)index as co-exposure to nitrogen oxides(NO_(x)),particulate matter<2.5μm(PM_(2.5)),particulate matter<10μm(PM10).Stratified Cox regression models were applied to test the effect of exposure.Effect modification of air pollution was assessed.Stratified Cox models through the indirect method and Aalen additive risk models were used in mediation analysis.Over median follow-up of 11.67 years,4596 AMD events were ascertained.Hazard ratios(HRs)and 95%confidence intervals(95%CIs)of incident AMD for pollution per interquartile range(IQR)increment were 1.10(1.04–1.16)for nitrogen dioxide(NO_(2)),1.09(1.03–1.15)for NO_(x),1.14(1.05–1.24)for PM_(2.5),1.13(1.05–1.21)for PM10.The HR(95%CI)of AMD associated with greenness 1000 m buffer per IQR increment was 0.91(0.86–0.97),300 m buffer was 0.94(0.89–0.99).The as-sociation between greenness 1000 m and AMD was 28.59%,44.77%,35.59%,32.31%and 27.08%mediated by the decreased WQS index,NO_(2),NO_(x),PM_(2.5) and PM10,respectively.Increased greenness was associated with lower AMD incidence,and air pollution partly mediate it,which implies that interventions aimed at improving air quality and increasing greenness could have a dual benefit in mitigating AMD risk.
基金Under the auspices of the Hong Kong Research Grants Council(No.14605920,14606922,14603724,C4023-20GF,8601219,8601242,3110151)a Grant from the Research Committee on Research Sustainability of Major Research Grants Council Funding Schemes of the Chinese University of Hong Kong(CUHK,No.3133235)the Vice-Chancellor’s One-off Discretionary Fund of CUHK(No.4930787)。
文摘Perception of air pollution is subjective and context-dependent.Previous studies exploring the association between measured air pollution and perceived air quality mainly focused on air pollution levels measured in the residence-based(RB)or regional context,overlooking the mobility-based(MB)context in which people are exposed to air pollution.This study measures air pollution levels in MB,RB,and regional contexts and examines their relationships with perceived air quality across different neighborhoods and gender sub-groups of Hong Kong,China to investigate how people perceive air quality.The results indicate that particulate matter 2.5(PM_(2.5))measured in RB and the regional context significantly contributes to people’s perceived air quality compared to MB PM_(2.5).Individuals in Central and Western district of Hong Kong rely on RB,regional and MB PM_(2.5) to assess air pollution.In Sham Shui Po,RB PM_(2.5) exhibits the highest influence on people’s perceived air quality,followed by regional PM_(2.5).Women’s perceived air quality is strongly related to their RB PM_(2.5) exposure,while men’s perceived air quality is associated with both RB PM_(2.5) and regional PM_(2.5) levels.We conclude that neighborhood effects and mobility levels are the two most important factors influencing the association between meas-ured air pollution and perceived air quality.We reveal that the neighborhood effect averaging problem(NEAP)influences the associ-ation between perceived air quality and measured air pollution levels in a way that differs from health outcome-related studies.Effect-ive measures are needed to improve the public’s awareness of air pollution,and scientific control should be implemented to reduce pub-lic exposure.
基金supported by the National Key Research&Development Program of China(No.2024YFB3910102).
文摘The rapid expansion of the low-altitude economy is driving strong demand for highly accurate and reliable positioning technologies to support diverse aerial operations.This review examines core positioning methodologies within the low-altitude intelligent network(LAIN)framework,beginning with an analysis of positioning requirements and performance metrics for low-altitude flight scenarios.It systematically assesses the principles,strengths,and limitations of mainstream positioning systems,including Global Navigation Satellite Systems(GNSS),terrestrial wireless positioning,and autonomous navigation,and it surveys prevalent integrated and cooperative positioning schemes.Our analysis demonstrates that standalone positioning technologies are inadequate in complex low-altitude settings,underscoring the pivotal role of multi-source fusion and unmanned aerial vehicle(UAV)swarm cooperative positioning as future trends.To address infrastructure gaps and high deployment costs in current LAIN systems,we propose a“space−air−ground”integrated and cooperative positioning architecture centered on GNSS and the 5th generation mobile communication technology(5G).The ground layer integrates 5G and GNSS for wide-area enhanced positioning.The aerial layer uses 5G aircraft-to-everything(A2X)and sidelink(SL)communications to build self-organizing networks for cooperative UAV localization.The space layer leverages low Earth orbit(LEO)satellites to overcome coverage limitations in communication and positioning.This hierarchical architecture reduces deployment costs through infrastructure reuse and enables deep integration of communication and navigation capabilities.By supporting collaborative enhancement across all three domains,the framework improves positioning robustness and delivers cost-effective,ubiquitous,and highly reliable positioning services.Finally,we outline promising research directions.This review aims to provide a systematic reference and a novel architectural perspective for the ongoing development of LAIN.
