Oxygen rich combustion is a mean to increase the energy efficiency and to contribute to CO2 capture. Influence of oxygen enriched air on the stability of methane flames from non premixed laminar jets has been investig...Oxygen rich combustion is a mean to increase the energy efficiency and to contribute to CO2 capture. Influence of oxygen enriched air on the stability of methane flames from non premixed laminar jets has been investigated experimentally. The burner consists of two coaxial jets： methane flowing out of the inner, oxidizer from the outer. The flame behavior is studied according to the proportion of oxygen in the oxidizer jet, the oxidizer and the methane jets velocities. The flame is either anchored to the burner, lifted, stationary or not or blown-out. The addition of oxygen produces a decrease of the lift height, a reduction of the length of the reaction zone and an increase in the soot emission. These results have been reported into diagrams of stability where the flame configurations are connected to the competition between the dynamic effect of the injection velocity and the chemical effect of oxygen addition.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
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
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
The oxygen-enriched direct smelting of jamesonite concentrate was carried out at 1250℃by changing the slag composition.The effects of Fe/SiO2 and Ca O/SiO2 mass ratios on the metal recovery rate as well as metal cont...The oxygen-enriched direct smelting of jamesonite concentrate was carried out at 1250℃by changing the slag composition.The effects of Fe/SiO2 and Ca O/SiO2 mass ratios on the metal recovery rate as well as metal content in slag were investigated.Experimental results indicated that the metal(Pb+Sb)recovery rate was up to 88.30%,and metal(Pb+Sb)content in slag was below 1 wt.%under the condition of slag composition of 21-22 wt.%Fe,19-20 wt.%SiO2 and 17-18 wt.%Ca O with Fe/SiO2 mass ratio of 1.1:1 and Ca O/SiO2 mass ratio of 0.9:1.The microanalysis of the alloy and slag demonstrated that the main phases in the alloy contained metallic Pb,metallic Sb and a small amount of Cu2 Sb and Fe Sb2 intermetallic compounds.The slag was mainly composed of kirschsteinite and fayalite.Zinc in the raw material was mainly oxidized into the slag phase in the form of zinc oxide.展开更多
For capturing and recycling of CO_(2)in the internal combustion engine,Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techn...For capturing and recycling of CO_(2)in the internal combustion engine,Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle.However,due to the water spray nozzle need to be installed on the cylinder,which increases the cylinder head design difficulty and makes the combustion conditions become more complicated.In this paper,a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines.The proposed new method uses liquid oxygen to solidify part of cooled CO_(2)from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system.The other part of CO_(2)is sent to inlet system and mixed with oxygen,which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable.Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program.The effects of exhaust gas recirculation(EGR)rate are analyzed on the temperatures,the pressures and the instantaneous heat release rates when the EGR rate is more than 8%.The possibility of enclosing intake and exhaust system for engine is verified.The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO_(2)capture experiment is carried out.The experimental results show that when the EGR rate is 36%for the optimum EGR rate.When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min,respectively,21.50-701.30 g dry ice is obtained.This research proposes a new design method which can capture CO_(2)for vehicular internal combustion engine.展开更多
The in-depth integration of healthy China with national fitness and the hope to achieve the long-term goal of “leading Sports Nation” by 2035, can’t be realized without gyms where people do physical exercise. The i...The in-depth integration of healthy China with national fitness and the hope to achieve the long-term goal of “leading Sports Nation” by 2035, can’t be realized without gyms where people do physical exercise. The international academic community recognizes that the 21<sup>st</sup> century is the golden time for sustainable and quality development. Taking a national perspective, authors of this paper studied the feasibility of building underground gyms in China through the approach of interdisciplinary research, as well as its dilemmas and pathways, and found out that quality development of underground space can effectively address challenges for large cities in China by increasing the resilience of urban area, and give full engage to underground capacity in striving for the goal of carbon peak and carbon neutrality. Underground gyms can also be incorporated into resident’s 15-min fitness circle, satisfying people’s needs of doing exercise at any time and in an easily-accessible place. However, China’s underground area development has been hindered by unclear property rights, chaotic action and utilization, and relatively backward laws and regulations. Moreover, building underground gyms still has to solve many problems such as poor air quality, severe sweat smell, and excessive bacteria and viruses. It is suggested that the capable authorities shall first clarify laws and regulations over place compound utilization, property rights and fire protection to facilitate the process of building underground gyms;encourage fitness practitioners to explore underground areas as gyms, and transfer their ground business to underground;then produce an intelligent and systematic solution of air quality improvement featuring oxygen-enrichment and “sterilization” with integration, a variety of instruments to monitor air quality of indoor gyms in real-time, to realize automatic control and management, and truly create worry-free and oxygen-enriched underground gyms with no sweat smell and no fear of bacteria and viruses.展开更多
Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poi...Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poisoning of air electrodes,causing substantial degradation in electrochemical performance and compromising the longterm stability of SOCs.This mini-review examines the mechanism of Cr deposition and poisoning in air electrodes under both fuel-cell and electrolysis modes.Furthermore,emphasis is placed on the recent advancements in strategies to mitigate Cr poisoning,offering insights into the rational design and development of active and Cr-tolerant air electrodes for SOCs.展开更多
Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage p...Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.展开更多
For oxygen-enriched blowing itself, the technique of pumping the desired oxygen content, increasing the actual coal supply in an all-round way, and accelerating the reaction rate of combustion in the sealed area, is a...For oxygen-enriched blowing itself, the technique of pumping the desired oxygen content, increasing the actual coal supply in an all-round way, and accelerating the reaction rate of combustion in the sealed area, is analyzed based on the thermodynamic perspective, can be achieved in a certain event among the increase in the speed and efficiency of combustion, increase the temperature, speed up melting. When the temperature is obviously high, it can effectively promote the reduction of metal oxides and the speed and effect of metal volatilization, enhancing the speed of oxygen-enriched air can not only improve the liquid-solid conversion of rose gas, improve and optimize the efficiency of fuel, promote the promotion of chemical reactions, promote the reaction. For the current slag treatment model for low-grade minerals, metal volatilization improves the actual need to strengthen the speed and efficiency of oxygen-enriched blast, improve efficiency and recovery. This research uses oxygen-enriched blast technology in the hope of reducing overall energy consumption, improving the operating environment, reducing the actual cost of production, and the application of oxygen-enriched technology in the flue gas furnace blowing process has an unprecedented market prospect and great promotion significance and value.展开更多
This study investigates the relationships between exposures to ambient air pollution—specifically particulate matter 2.5 (PM_(2.5)) and its metabolites—and the risk of depression.Nonlinear and linear regression,Baye...This study investigates the relationships between exposures to ambient air pollution—specifically particulate matter 2.5 (PM_(2.5)) and its metabolites—and the risk of depression.Nonlinear and linear regression,Bayesian kernel machine regression,and toxicogenomic analysis were key approaches.PM_(2.5)exposure was positively associated with the risk of developing depression,whereas phenylglyoxylic acid exposure was negatively associated with depression risk.We found a significant overall relationship between ambient air pollution and depression,particularly at the 55th and 60th percentiles.Although statistical significance was not reached at the 65th percentile,there was a noticeable upward trend,indicating a potential association.Interestingly,no significant connection was found between a combination of metabolites from ambient air pollution and depression.PM_(2.5)and phenylglyoxylic acid emerged as the most influential compounds in the models,respectively.PM_(2.5)exposure altered the expression of 42 specific targets associated with depression,especially POMC,SCL6A4,IL6,and SOD2.The study identified specific pathways related to insulin secretion,energy metabolism,blood circulation,tube diameter,and maintenance of blood vessel diameter,as well as key molecular mechanisms involving hsa-miR-124-3p,hsa-miR-155-5p,hsa-miR-16-5p,and SP1.These mechanisms were found to underlie the etiology of depression associated with PM_(2.5)exposure.In conclusions,PM_(2.5)and phenylglyoxylic acid were found to be associated with depression.Further work is needed to gain insight into the molecular mechanisms by which these chemicals affect depression,especially pathways related to insulin secretion and blood circulation.展开更多
Large-scale deployment of carbon dioxide(CO_(2))removal technology is an essential step to cope with global warming and achieve carbon neutrality.Direct air capture(DAC)has recently received increasing attention given...Large-scale deployment of carbon dioxide(CO_(2))removal technology is an essential step to cope with global warming and achieve carbon neutrality.Direct air capture(DAC)has recently received increasing attention given the high flexibility to remove CO_(2)from discrete sources.Porous materials with adjustable pore characteristics are promising sorbents with low or no latent heat of vaporization.This review article has summarized the recent development of porous sorbents for DAC,with a focus of pore engineering strategy and adsorption mechanism.Physisorbents such as zeolites,porous carbons,metal-organic frameworks(MOFs),and amine-modified chemisorbents have been discussed and their challenges in practical application have been analyzed.At last,future directions have been proposed,and it is expected to inspire collaborations from chemistry,environment,material science and engineering communities.展开更多
Air pollution in China covers a large area with complex sources and formation mechanisms,making it a unique place to conduct air pollution and atmospheric chemistry research.The National Natural Science Foundation of ...Air pollution in China covers a large area with complex sources and formation mechanisms,making it a unique place to conduct air pollution and atmospheric chemistry research.The National Natural Science Foundation of China’s Major Research Plan entitled“Fundamental Researches on the Formation and Response Mechanism of the Air Pollution Complex in China”(or the Plan)has funded 76 research projects to explore the causes of air pollution in China,and the key processes of air pollution in atmospheric physics and atmospheric chemistry.In order to summarize the abundant data from the Plan and exhibit the long-term impacts domestically and internationally,an integration project is responsible for collecting the various types of data generated by the 76 projects of the Plan.This project has classified and integrated these data,forming eight categories containing 258 datasets and 15 technical reports in total.The integration project has led to the successful establishment of the China Air Pollution Data Center(CAPDC)platform,providing storage,retrieval,and download services for the eight categories.This platform has distinct features including data visualization,related project information querying,and bilingual services in both English and Chinese,which allows for rapid searching and downloading of data and provides a solid foundation of data and support for future related research.Air pollution control in China,especially in the past decade,is undeniably a global exemplar,and this data center is the first in China to focus on research into the country’s air pollution complex.展开更多
Food systems are deeply affected by climate change and air pollution,while being key contributors to these environmental challenges.Understanding the complex interactions among food systems,climate change,and air poll...Food systems are deeply affected by climate change and air pollution,while being key contributors to these environmental challenges.Understanding the complex interactions among food systems,climate change,and air pollution is crucial for mitigating climate change,improving air quality,and promoting the sustainable development of food systems.However,the literature lacks a comprehensive review of these interactions,particularly in the current phase of rapid development in the field.To address this gap,this study systematically reviews recent research on the impacts of climate change and air pollution on food systems,as well as the greenhouse gas and air pollutant emissions from agri-food systems and their contribution to global climate change and air pollution.In addition,this study summarizes various strategies for mitigation and adaptation,including adjustments in agricultural practices and food supply chains.Profound changes in food systems are urgently needed to enhance adaptability and reduce emissions.This review offers a critical overview of current research on the interactions among food systems,climate change,and air pollution and highlights future research directions to support the transition to sustainable food systems.展开更多
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
1.Introduction Mobile communications have catalyzed a new era of informa-tion technology revolution,significantly broadening and deepen-ing human-to-human,human-to-machine,and machine-to-machine connections.With their...1.Introduction Mobile communications have catalyzed a new era of informa-tion technology revolution,significantly broadening and deepen-ing human-to-human,human-to-machine,and machine-to-machine connections.With their incredible speed of development and wide-reaching impact,mobile communications serve as the cornerstone of the Internet of Everything,profoundly reshaping human cognitive abilities and ways of thinking.Furthermore,mobile communications are altering the patterns of production and life,driving leaps in productivity quality,and strongly promot-ing innovation within human civilization.展开更多
Developing highly active and stable air electrodes remains challenging for reversible solid oxide cells(R-SOCs).Herein,we re-port an A-site high-entropy engineered perovskite oxide,La_(0.2)Pr_(0.2)Nd_(0.2)Ba_(0.2)Sr_(...Developing highly active and stable air electrodes remains challenging for reversible solid oxide cells(R-SOCs).Herein,we re-port an A-site high-entropy engineered perovskite oxide,La_(0.2)Pr_(0.2)Nd_(0.2)Ba_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF),and its electrocatalytic activity and stability property are systematically probed for tubular R-SOCs.The HE-LSCF air electrode exhibits excellent oxygen reduction reac-tion(ORR)activity with a low polarization resistance of 0.042Ω·cm^(2)at 700℃,which is much lower than that of La0.6Sr0.4Co_(0.8)Fe_(0.2)O_(3−δ)(LSCF),indicating the excellent catalytic activity of HE-LSCF.Meanwhile,the tubular R-SOCs with HE-LSCF shows a high peak power density of 1.18 W·cm^(−2)in the fuel cell mode and a promising electrolysis current density of−0.52 A·cm^(−2)at 1.5 V in the electrolysis mode with H_(2)(~10%H_(2)O)atmosphere at 700℃.More importantly,the tubular R-SOCs with HE-LSCF shows favorable stability under 180 h reversible cycling test.Our results show the high-entropy design can significantly enhance the activity and robustness of LSCF electrode for tubular R-SOCs.展开更多
Concerns about air quality in dental clinics where aerosol generation during procedures poses significant health risks,have prompted investigations on advanced disinfection technologies.This editorial describes the st...Concerns about air quality in dental clinics where aerosol generation during procedures poses significant health risks,have prompted investigations on advanced disinfection technologies.This editorial describes the strengths and limitations of ventilation and aerosol control measures in dental offices,especially with respect to the use of graphene nanocomposites.The potential of graphene nanocomposites as an innovative solution to aerosol-associated health risks is examined in this review due to the unique properties of graphene(e.g.,high con-ductivity,mechanical strength,and antimicrobial activity).These properties have produced promising results in various fields,but the application of graphene in dentistry remains unexplored.The recent study by Ju et al which was published in World Journal of Clinical Cases evaluated the effectiveness of graphene-based air disinfection systems in dental clinics.The study demonstrated that graphene-based disinfection techniques produced significant reductions in suspended particulate matter and bacterial colony counts,when co-mpared with traditional methods.Despite these positive results,challenges such as material saturation,frequency of filter replacement,and associated costs must be addressed before widespread adoption of graphene-based disinfection techniques in clinical practice.Therefore,there is need for further research on material structure optimization,long-term safety evaluations,and broader clinical applications,in order to maximize their positive impact on public health.展开更多
文摘Oxygen rich combustion is a mean to increase the energy efficiency and to contribute to CO2 capture. Influence of oxygen enriched air on the stability of methane flames from non premixed laminar jets has been investigated experimentally. The burner consists of two coaxial jets： methane flowing out of the inner, oxidizer from the outer. The flame behavior is studied according to the proportion of oxygen in the oxidizer jet, the oxidizer and the methane jets velocities. The flame is either anchored to the burner, lifted, stationary or not or blown-out. The addition of oxygen produces a decrease of the lift height, a reduction of the length of the reaction zone and an increase in the soot emission. These results have been reported into diagrams of stability where the flame configurations are connected to the competition between the dynamic effect of the injection velocity and the chemical effect of oxygen addition.
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 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Project(51474248)supported by the National Natural Science Foundation of China
文摘The oxygen-enriched direct smelting of jamesonite concentrate was carried out at 1250℃by changing the slag composition.The effects of Fe/SiO2 and Ca O/SiO2 mass ratios on the metal recovery rate as well as metal content in slag were investigated.Experimental results indicated that the metal(Pb+Sb)recovery rate was up to 88.30%,and metal(Pb+Sb)content in slag was below 1 wt.%under the condition of slag composition of 21-22 wt.%Fe,19-20 wt.%SiO2 and 17-18 wt.%Ca O with Fe/SiO2 mass ratio of 1.1:1 and Ca O/SiO2 mass ratio of 0.9:1.The microanalysis of the alloy and slag demonstrated that the main phases in the alloy contained metallic Pb,metallic Sb and a small amount of Cu2 Sb and Fe Sb2 intermetallic compounds.The slag was mainly composed of kirschsteinite and fayalite.Zinc in the raw material was mainly oxidized into the slag phase in the form of zinc oxide.
基金Supported by National Natural Science Foundation of China(Grant No.51176082)Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions of China(Grant No.CIT&TCD20140311)Beijing Municipal Natural Science Foundation of China(Grant No.SQKZ201510016004)
文摘For capturing and recycling of CO_(2)in the internal combustion engine,Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle.However,due to the water spray nozzle need to be installed on the cylinder,which increases the cylinder head design difficulty and makes the combustion conditions become more complicated.In this paper,a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines.The proposed new method uses liquid oxygen to solidify part of cooled CO_(2)from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system.The other part of CO_(2)is sent to inlet system and mixed with oxygen,which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable.Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program.The effects of exhaust gas recirculation(EGR)rate are analyzed on the temperatures,the pressures and the instantaneous heat release rates when the EGR rate is more than 8%.The possibility of enclosing intake and exhaust system for engine is verified.The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO_(2)capture experiment is carried out.The experimental results show that when the EGR rate is 36%for the optimum EGR rate.When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min,respectively,21.50-701.30 g dry ice is obtained.This research proposes a new design method which can capture CO_(2)for vehicular internal combustion engine.
文摘The in-depth integration of healthy China with national fitness and the hope to achieve the long-term goal of “leading Sports Nation” by 2035, can’t be realized without gyms where people do physical exercise. The international academic community recognizes that the 21<sup>st</sup> century is the golden time for sustainable and quality development. Taking a national perspective, authors of this paper studied the feasibility of building underground gyms in China through the approach of interdisciplinary research, as well as its dilemmas and pathways, and found out that quality development of underground space can effectively address challenges for large cities in China by increasing the resilience of urban area, and give full engage to underground capacity in striving for the goal of carbon peak and carbon neutrality. Underground gyms can also be incorporated into resident’s 15-min fitness circle, satisfying people’s needs of doing exercise at any time and in an easily-accessible place. However, China’s underground area development has been hindered by unclear property rights, chaotic action and utilization, and relatively backward laws and regulations. Moreover, building underground gyms still has to solve many problems such as poor air quality, severe sweat smell, and excessive bacteria and viruses. It is suggested that the capable authorities shall first clarify laws and regulations over place compound utilization, property rights and fire protection to facilitate the process of building underground gyms;encourage fitness practitioners to explore underground areas as gyms, and transfer their ground business to underground;then produce an intelligent and systematic solution of air quality improvement featuring oxygen-enrichment and “sterilization” with integration, a variety of instruments to monitor air quality of indoor gyms in real-time, to realize automatic control and management, and truly create worry-free and oxygen-enriched underground gyms with no sweat smell and no fear of bacteria and viruses.
基金supported by National Natural Science Foundation of China(22279018)National Natural Science Foundation of China(22005055)Natural Science Foundation of Fujian Province(2022J01085).
文摘Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poisoning of air electrodes,causing substantial degradation in electrochemical performance and compromising the longterm stability of SOCs.This mini-review examines the mechanism of Cr deposition and poisoning in air electrodes under both fuel-cell and electrolysis modes.Furthermore,emphasis is placed on the recent advancements in strategies to mitigate Cr poisoning,offering insights into the rational design and development of active and Cr-tolerant air electrodes for SOCs.
基金supported by Fundamental Research Funds for the Central Universities(2023KYJD1008)the Science Research Projects of the Anhui Higher Education Institutions of China(2022AH051582).
文摘Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.
文摘For oxygen-enriched blowing itself, the technique of pumping the desired oxygen content, increasing the actual coal supply in an all-round way, and accelerating the reaction rate of combustion in the sealed area, is analyzed based on the thermodynamic perspective, can be achieved in a certain event among the increase in the speed and efficiency of combustion, increase the temperature, speed up melting. When the temperature is obviously high, it can effectively promote the reduction of metal oxides and the speed and effect of metal volatilization, enhancing the speed of oxygen-enriched air can not only improve the liquid-solid conversion of rose gas, improve and optimize the efficiency of fuel, promote the promotion of chemical reactions, promote the reaction. For the current slag treatment model for low-grade minerals, metal volatilization improves the actual need to strengthen the speed and efficiency of oxygen-enriched blast, improve efficiency and recovery. This research uses oxygen-enriched blast technology in the hope of reducing overall energy consumption, improving the operating environment, reducing the actual cost of production, and the application of oxygen-enriched technology in the flue gas furnace blowing process has an unprecedented market prospect and great promotion significance and value.
文摘This study investigates the relationships between exposures to ambient air pollution—specifically particulate matter 2.5 (PM_(2.5)) and its metabolites—and the risk of depression.Nonlinear and linear regression,Bayesian kernel machine regression,and toxicogenomic analysis were key approaches.PM_(2.5)exposure was positively associated with the risk of developing depression,whereas phenylglyoxylic acid exposure was negatively associated with depression risk.We found a significant overall relationship between ambient air pollution and depression,particularly at the 55th and 60th percentiles.Although statistical significance was not reached at the 65th percentile,there was a noticeable upward trend,indicating a potential association.Interestingly,no significant connection was found between a combination of metabolites from ambient air pollution and depression.PM_(2.5)and phenylglyoxylic acid emerged as the most influential compounds in the models,respectively.PM_(2.5)exposure altered the expression of 42 specific targets associated with depression,especially POMC,SCL6A4,IL6,and SOD2.The study identified specific pathways related to insulin secretion,energy metabolism,blood circulation,tube diameter,and maintenance of blood vessel diameter,as well as key molecular mechanisms involving hsa-miR-124-3p,hsa-miR-155-5p,hsa-miR-16-5p,and SP1.These mechanisms were found to underlie the etiology of depression associated with PM_(2.5)exposure.In conclusions,PM_(2.5)and phenylglyoxylic acid were found to be associated with depression.Further work is needed to gain insight into the molecular mechanisms by which these chemicals affect depression,especially pathways related to insulin secretion and blood circulation.
基金financial support from the National Natural Science Foundation of China(Nos.22278011,22225803,22038001 and 22108007)Beijing Natural Science Foundation(No.Z230023)+1 种基金The Science&Technology Project of Beijing Municipal Education Committee(No.KZ201810005004)Beijing Nova Program(No.Z211100002121094)。
文摘Large-scale deployment of carbon dioxide(CO_(2))removal technology is an essential step to cope with global warming and achieve carbon neutrality.Direct air capture(DAC)has recently received increasing attention given the high flexibility to remove CO_(2)from discrete sources.Porous materials with adjustable pore characteristics are promising sorbents with low or no latent heat of vaporization.This review article has summarized the recent development of porous sorbents for DAC,with a focus of pore engineering strategy and adsorption mechanism.Physisorbents such as zeolites,porous carbons,metal-organic frameworks(MOFs),and amine-modified chemisorbents have been discussed and their challenges in practical application have been analyzed.At last,future directions have been proposed,and it is expected to inspire collaborations from chemistry,environment,material science and engineering communities.
基金supported by the National Natural Science Foundation of China(Grant No.92044303)。
文摘Air pollution in China covers a large area with complex sources and formation mechanisms,making it a unique place to conduct air pollution and atmospheric chemistry research.The National Natural Science Foundation of China’s Major Research Plan entitled“Fundamental Researches on the Formation and Response Mechanism of the Air Pollution Complex in China”(or the Plan)has funded 76 research projects to explore the causes of air pollution in China,and the key processes of air pollution in atmospheric physics and atmospheric chemistry.In order to summarize the abundant data from the Plan and exhibit the long-term impacts domestically and internationally,an integration project is responsible for collecting the various types of data generated by the 76 projects of the Plan.This project has classified and integrated these data,forming eight categories containing 258 datasets and 15 technical reports in total.The integration project has led to the successful establishment of the China Air Pollution Data Center(CAPDC)platform,providing storage,retrieval,and download services for the eight categories.This platform has distinct features including data visualization,related project information querying,and bilingual services in both English and Chinese,which allows for rapid searching and downloading of data and provides a solid foundation of data and support for future related research.Air pollution control in China,especially in the past decade,is undeniably a global exemplar,and this data center is the first in China to focus on research into the country’s air pollution complex.
基金supported by the National Natural Science Foundation of China(42277087,42130708,42471021,42277482,and 42361144876)the Natural Science Foundation of Guangdong Province(2024A1515012550)+3 种基金the Hainan Institute of National Park grant(KY-23ZK01)the Tsinghua Shenzhen International Graduate School Cross-disciplinary Research and Innovation Fund Research Plan(JC2022011)the Shenzhen Science and Technology Program(JCYJ20240813112106009 and ZDSYS20220606100806014)the Scientific Research Start-up Funds(QD2021030C)from Tsinghua Shenzhen International Graduate School。
文摘Food systems are deeply affected by climate change and air pollution,while being key contributors to these environmental challenges.Understanding the complex interactions among food systems,climate change,and air pollution is crucial for mitigating climate change,improving air quality,and promoting the sustainable development of food systems.However,the literature lacks a comprehensive review of these interactions,particularly in the current phase of rapid development in the field.To address this gap,this study systematically reviews recent research on the impacts of climate change and air pollution on food systems,as well as the greenhouse gas and air pollutant emissions from agri-food systems and their contribution to global climate change and air pollution.In addition,this study summarizes various strategies for mitigation and adaptation,including adjustments in agricultural practices and food supply chains.Profound changes in food systems are urgently needed to enhance adaptability and reduce emissions.This review offers a critical overview of current research on the interactions among food systems,climate change,and air pollution and highlights future research directions to support the transition to sustainable food systems.
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.
基金supported by the National Key Research and Develop-ment Program of China(2019YFB1803400).
文摘1.Introduction Mobile communications have catalyzed a new era of informa-tion technology revolution,significantly broadening and deepen-ing human-to-human,human-to-machine,and machine-to-machine connections.With their incredible speed of development and wide-reaching impact,mobile communications serve as the cornerstone of the Internet of Everything,profoundly reshaping human cognitive abilities and ways of thinking.Furthermore,mobile communications are altering the patterns of production and life,driving leaps in productivity quality,and strongly promot-ing innovation within human civilization.
基金support provided by the National Key R&D Program of China(No.2024YFE0101500)the National Natural Science Foundation of China(No.52272257)the Natural Science Foundation of Jiangsu Province(No.BK20240109).
文摘Developing highly active and stable air electrodes remains challenging for reversible solid oxide cells(R-SOCs).Herein,we re-port an A-site high-entropy engineered perovskite oxide,La_(0.2)Pr_(0.2)Nd_(0.2)Ba_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF),and its electrocatalytic activity and stability property are systematically probed for tubular R-SOCs.The HE-LSCF air electrode exhibits excellent oxygen reduction reac-tion(ORR)activity with a low polarization resistance of 0.042Ω·cm^(2)at 700℃,which is much lower than that of La0.6Sr0.4Co_(0.8)Fe_(0.2)O_(3−δ)(LSCF),indicating the excellent catalytic activity of HE-LSCF.Meanwhile,the tubular R-SOCs with HE-LSCF shows a high peak power density of 1.18 W·cm^(−2)in the fuel cell mode and a promising electrolysis current density of−0.52 A·cm^(−2)at 1.5 V in the electrolysis mode with H_(2)(~10%H_(2)O)atmosphere at 700℃.More importantly,the tubular R-SOCs with HE-LSCF shows favorable stability under 180 h reversible cycling test.Our results show the high-entropy design can significantly enhance the activity and robustness of LSCF electrode for tubular R-SOCs.
文摘Concerns about air quality in dental clinics where aerosol generation during procedures poses significant health risks,have prompted investigations on advanced disinfection technologies.This editorial describes the strengths and limitations of ventilation and aerosol control measures in dental offices,especially with respect to the use of graphene nanocomposites.The potential of graphene nanocomposites as an innovative solution to aerosol-associated health risks is examined in this review due to the unique properties of graphene(e.g.,high con-ductivity,mechanical strength,and antimicrobial activity).These properties have produced promising results in various fields,but the application of graphene in dentistry remains unexplored.The recent study by Ju et al which was published in World Journal of Clinical Cases evaluated the effectiveness of graphene-based air disinfection systems in dental clinics.The study demonstrated that graphene-based disinfection techniques produced significant reductions in suspended particulate matter and bacterial colony counts,when co-mpared with traditional methods.Despite these positive results,challenges such as material saturation,frequency of filter replacement,and associated costs must be addressed before widespread adoption of graphene-based disinfection techniques in clinical practice.Therefore,there is need for further research on material structure optimization,long-term safety evaluations,and broader clinical applications,in order to maximize their positive impact on public health.
