Rubber-toughened thermoplastic materials have become ubiquitous in modern society owing to their lightweight nature and desirable combination of advantageous performances.Despite the ever-increasing demand,the develop...Rubber-toughened thermoplastic materials have become ubiquitous in modern society owing to their lightweight nature and desirable combination of advantageous performances.Despite the ever-increasing demand,the development of polymer alloys that are lightweight,high-strength,and high-toughness remains an ongoing challenge.Inspired by the unique“salami”microstructure from commercial acrylonitrile butadiene styrene copolymer(ABS)and high-impact polystyrene(HIPS),a facile approach was developed to overcome the trade-off between enhancing the toughness and rigidity of fully polymer-based alloys by virtue of elastomeric salami particles.This strategy entails pre-grafting rigid poly(lactic acid)(PLLA)chains with glycidyl methacrylate-grafted octene ethylene copolymer(POE-g-GMA)using complementary reactive groups.It can be envisaged that the PLLA grafts featuring strong incompatibility with polypropylene(PP)remain fixed in elastomer phase upon the subsequent melt compounding,facilitating the in situ formation of“hard core(PLLA)-soft shell(polyolefin elastomer,POE)”particles in polypropylene(PP)matrix.The all-polymer alloys containing elastomeric salami particles demonstrated unprecedented performance combinations,including upper notched impact strengths(56.8 kJ/m2),even higher tensile strength(36.8 MPa),and Young’s modulus(0.93 GPa)than that of the PP matrix.Furthermore,these materials are lightweight without the incorporation of reinforcing nano-fillers,which is competitive with industrial engineering plastics.It is highly anticipated that this universal and highly efficient protocol will be appropriate for arbitrary rubber toughened/reinforced systems,offering a paradigm in the design of advanced all-polymer alloys.展开更多
Imidazole(IM)particles in the atmosphere affect climate,atmospheric chemical reactions,and human health.However,research on IM particles in the Sichuan Basin(SCB),one of the areas of China affected most heavily by haz...Imidazole(IM)particles in the atmosphere affect climate,atmospheric chemical reactions,and human health.However,research on IM particles in the Sichuan Basin(SCB),one of the areas of China affected most heavily by haze,remains very scarce.This study used single-particle aerosol mass spectrometry to investigate IM-containing particles in Chengdu,one of the megacities in the SCB,during summer and winter before and after implemen-tation of the Three-year Action Plan to Win the Blue-Sky Defense War(BSDW).We found that IM-containing particles accounted for 1.2%–12.0%of all detected particles,and they highly mixed with carbonaceous com-ponents,secondary inorganic species,and organic nitrogen.From before to after the BSDW,the proportion of IM-containing particles decreased by 1.8%in summer,but increased by 9.6%in winter.Ammonium/amines and carbonyl compounds were closely related to IM-containing particles;the highest proportion of IM-containing particles occurred in particles mixed with amines and carbonyls.The number fraction of IM-containing particles in all seasons was higher at night than during daytime.The potential source areas of IM-containing particles showed notable narrowing after the BSDW,and the high-value areas were found distributed closer to Chengdu and its surrounding areas.In the winter before the BSDW,most IM-containing particles(>70%)were mixed with organic carbon(OC)particles,and the contributions of OC and mixed organic–elemental carbon(OC-EC)particles increased with aggravation of pollution,whereas OC-EC and Metal particles played a more crucial role in the winter after the BSDW.展开更多
DealEdrtor,Dear Editor,Spodoptera litura,commonly known as the tobacco cutworm,is a polyphagous agricultural pest worldwide,causing significant economic losses to a wide range of crops.Over the past decades,S.litura h...DealEdrtor,Dear Editor,Spodoptera litura,commonly known as the tobacco cutworm,is a polyphagous agricultural pest worldwide,causing significant economic losses to a wide range of crops.Over the past decades,S.litura has developed high resistance levels to multiple chemical insecticides(Li et al.,2024),and shown low susceptibility to transgenic Bacillus thuringiensis(Bt)cotton(Wan et al.,2008).展开更多
Colitis-associated colorectal cancer(CAC)is a major contributor to cancer-related mortality worldwide.Titanium dioxide(TiO_(2),E171),a widely used food additive,has been insufficiently studied regarding its effects on...Colitis-associated colorectal cancer(CAC)is a major contributor to cancer-related mortality worldwide.Titanium dioxide(TiO_(2),E171),a widely used food additive,has been insufficiently studied regarding its effects on macrophages within colon tumors during CAC development.In this study,CAC mouse models were used to investigate the biological impact of dietary E171 on macrophages in vivo,while lipopolysaccharide(LPS)-stimulated RAW264.7 macrophage cell lines were employed to elucidate the underlying mechanisms in vitro.We found that dietary E171 intake accelerated CAC development,exacerbated inflammatory responses and oxidative stress,and upregulated CAC-associated genes,including S100a8,S100a9,Lcn2,S100a11,Cxcl2,and interleukin-1α(Il-1α).E171 also increased the expression of S100A8,S100A9,NOD-like receptor family pyrin domain-containing 3(NLRP3),and gasdermin-D Nterminal(GSDMD-N)in macrophages within colon tumors.In inflammatory macrophages,E171 exposure enhanced cell viability,increased reactive oxygen species(ROS)levels,and elevated the expression and secretion of S100A8 and S100A9,consistent with in vivo histological observations.Furthermore,E171-induced secretion of S100A8 and S100A9 in macrophages was suppressed by specific inhibitors,including N-acetylcysteine(NAC,ROS inhibitor),MCC950(NLRP3 inhibitor),Z-YVAD-FMK(caspase 1 inhibitor),disulfiram(GSDMD inhibitor),and transfection of NLRP3 small interfering ribonucleic acid(siRNA).These results indicate that dietary E171 promotes CAC development by activating macrophages,with S100A8 and S100A9 serving as key mediators,and the NLRP3/caspase 1/GSDMD pathway acting as a critical mechanism.展开更多
Rapid corrosion of magnesium alloys in the physiological environment limits their use as orthopedic implant materials.Therefore,the silane film modified with nano-hydroxyapatite(n HA)was prepared on the surface of AZ3...Rapid corrosion of magnesium alloys in the physiological environment limits their use as orthopedic implant materials.Therefore,the silane film modified with nano-hydroxyapatite(n HA)was prepared on the surface of AZ31 magnesium alloy to improve its corrosion resistance.The silane films are continuous,uniform,and adherent well to the Mg substrate,and the modification of the film by n HA increased the thickness from~1.92 to~3.25μm.Compared to the bare substrate,the corrosion current density of the sample with the silane film modified with n HA decreases by three orders of magnitude from 9.23×10^(-5)to 2.779×10^(-8)A/cm~2.According to the immersion tests,it is found that the synergistic effect of sub-film corrosion and blistering is the dominant mode of film failure.During the immersion of less than 72 h,the modification by n HA improves the corrosion resistance by delaying the sub-film corrosion and blistering of the film.展开更多
In this study,we perform particle-resolved simulations of settling spheroidal particles,considering oblate and prolate spheroids and spheres,and investigate the shape effect on the particle dynamics in suspensions wit...In this study,we perform particle-resolved simulations of settling spheroidal particles,considering oblate and prolate spheroids and spheres,and investigate the shape effect on the particle dynamics in suspensions with volume fraction 1%and 5%.We first examine the single-point statistics of the translational and rotational motion of the settling particles.The horizontal velocity has a symmetrical distribution with standard deviation dependent on the particle shape.The greater horizontal velocity fluctuations of the non-spherical particles,compared to that of spheres,are attributed to the horizontal drift of settling spheroids with oblique orientations induced by the fluid-particle and particle-particle interactions.The fluctuation of particle vertical velocity,instead,is skewed under the effect of wake-induced hydrodynamic interactions.Further,we explore the particle pair statistics,which demonstrate the formation of column-like particle micro-structures for the lowest volume fraction considered.This clustering is more pronounced for spheroidal particles than spheres,due to the stronger attractions among vertically-aligned settling spheroids.Moreover,the particle pair statistics are directly related to the collision rate among the dispersed particles.The local accumulation of oblate/prolate spheroids serves as the major mechanism to promote the particle-particle collisions in dilute suspensions.展开更多
An in-depth understanding of the behaviours of solid propellants under low-velocity impact loads is crucial for enhancing their safety in applications such as aerospace propulsion.This study investigated the dynamic r...An in-depth understanding of the behaviours of solid propellants under low-velocity impact loads is crucial for enhancing their safety in applications such as aerospace propulsion.This study investigated the dynamic responses of single ammonium perchlorate(AP)/octogen(HMX)particles embedded in a hydroxyl-terminated polybutadiene(HTPB)binder under dynamic compression loading via real-time synchrotron-based X-ray phase contrast imaging and a modified split Hopkinson pressure bar(SHPB)system.The compression of the viscoelastic binder and subsequent dynamic fracturing of the AP/HMX particles were captured.During compression,transverse cracks developed within the AP particles,and their propagation led to particle fracturing,resulting in ductile fracturing.Unlike AP,HMX generated numerous short cracks within the internal and edge regions simultaneously,leading to fragmentation and brittle fracturing.Moreover,particle damage reduced the modulus of the sample,shifting its dynamic stress response from nonlinear elasticity to strain softening and further strain hardening as the binder exhibited plastic deformation.A compression simulation incorporating a real particle microscopic structure was established to study the mechanical response of the interface and particles.The simulation results agreed with the experimental observations.These results indicate that the shear stress at the HTPB-AP interface is greater than that at the HTPB-HMX interface,which is a factor influencing the differences in the mesoscale damage mechanisms of the particles.展开更多
We show that in Schwarzschild equivalent mediums,the massless spin particles obey the same dynamical equation,from which we obtain remarkably simple formulae for the frequencies of the quasibound states.We find that t...We show that in Schwarzschild equivalent mediums,the massless spin particles obey the same dynamical equation,from which we obtain remarkably simple formulae for the frequencies of the quasibound states.We find that the quasibound frequencies of different bosons can be identical at the same quantum number l,and the same is true of different fermions,but a quasibound frequency for bosons can never equal a quasibound frequency for fermions.These results mean that in Schwarzschild equivalent mediums with the quasibound-state boundary conditions,characteristics of electromagnetic waves are the same as those for all the massless bosonic waves,thereby allowing electromagnetic waves to simulate gravitational waves.Our predictions can be tested in future experiments,building upon the successful preparation of Schwarzschild equivalent mediums.展开更多
Although the strengthening and grain refinement effects of TiB_(2) particles on aluminum alloys have been extensively studied,their influence on casting behavior remains relatively underexplored.In this study,the infl...Although the strengthening and grain refinement effects of TiB_(2) particles on aluminum alloys have been extensively studied,their influence on casting behavior remains relatively underexplored.In this study,the influence of different addition amounts of submicron TiB_(2) particles on the microstructure,casting performance,and mechanical properties of an Al-Cu(ZL205A)alloy was systematically investigated.The introduction of TiB_(2) particles leads to significant grain refinement,transforming the microstructure from coarse grains to fine equiaxed grains by providing additional nucleation sites and inhibiting grain growth.SEM and TEM analyses reveal that the added submicron TiB_(2) particles exhibit minimal effect on the distribution of intermetallic phases or precipitates.Casting performance,as evaluated by spiral fluidity and hot tearing tests,shows notable improvements with TiB_(2) additions.At a TiB_(2) content of 3wt.%,the fluidity length increases by 20%,and the hot tearing susceptibility coefficient decreases by 29%.These enhancements are mainly due to the refined grain structure and the formation of interdendritic bridging in TiB_(2)-reinforced alloys.However,the overall enahncement in casting properties shows little variation across the TiB_(2) additions from 0.2wt.% to 3wt.%.Mechanical testing shows that the highest hardness and strength are achieved with a 1wt.%addition of TiB_(2) particles,primarily attributed to refined grain size and reinforcement of the aluminum matrix.Based on these findings,a TiB_(2) particle content of 1wt.%is recommended for optimizing both the casting performance and mechanical properties of the ZL205A alloy.展开更多
WC particles reinforced CoCrFeNiMo high-entropy alloy(HEA)composite coatings were prepared on Cr12MoV steel successfully by laser cladding technology to improve the wear resistance of substrates.Effect of WC content o...WC particles reinforced CoCrFeNiMo high-entropy alloy(HEA)composite coatings were prepared on Cr12MoV steel successfully by laser cladding technology to improve the wear resistance of substrates.Effect of WC content on microstructure and wear property of the composite coatings was studied in detail.Large numbers of carbides with four main types:primary carbide crystals,eutectic structures,massive crystals growing along the periphery of the remaining WC particles and incompletely fused WC particles,were found to exist in the WC/CoCrFeNiMo composite coatings.With increasing WC content,the microhardness of coatings is gradually improved while the average friction coefficients follow the opposite trend due to solid solution strengthening and second phase strengthening effect.The maximum microhardness and minimum friction coefficient are HV_(0.2)689.7 and 0.72,respectively,for the composite coating with 30 wt.%WC,the wear resistance of the substrate is improved significantly,the wear mechanisms are spalling wear and abrasive wear due to their high microhardness.展开更多
Polybrominated biphenyl ethers(PBDEs)and polycyclic aromatic hydrocarbons(PAHs)are commonly detected contaminants at e-waste recycling sites.Against the conventional wisdom that PBDEs and PAHs are highly immobile and ...Polybrominated biphenyl ethers(PBDEs)and polycyclic aromatic hydrocarbons(PAHs)are commonly detected contaminants at e-waste recycling sites.Against the conventional wisdom that PBDEs and PAHs are highly immobile and persist primarily in shallowsurface soils,increasing evidence shows that these compounds can leach into the groundwater.Herein,we compare the leachabilities of PBDEs vs.PAHs from contaminated soils collected at an e-waste recycling site in Tianjin,China.Considerable amounts of BDE-209(0.3–2 ng/L)and phenanthrene(42–106 ng/L),the most abundant PBDE and PAH at the site,are detected in the effluents of columns packed with contaminated soils,with the specific concentrations varying with hydrodynamic and solution chemistry conditions.Interestingly,the leaching potential of BDE-209 appears to be closely related to the release of colloidal mineral particles,whereas the leachability of phenanthrene correlates well with the concentration of dissolved organic carbon in the effluent,but showing essentially no correlation with the concentration of mineral particles.The surprisingly different trends of the leachability observed between BDE-209 and phenanthrene is counterintuitive,as PBDEs and PAHs often co-exist at e-waste recycling sites(particularly at the sites wherein incineration is being practiced)and share many similarities in terms of physicochemical properties.One possible explanation is that due to its extremely low solubility,BDE-209 predominantly exists in free-phase(i.e.,as solid(nano)particles),whereas the more soluble phenanthrene is mainly sorbed to soil organic matter.Findings in this study underscore the need to better understand the mobility of highly hydrophobic organic contaminants at contaminated sites for improved risk management.展开更多
Thermodynamic modeling is still themostwidely usedmethod to characterize aerosol acidity,a critical physicochemical property of atmospheric aerosols.However,it remains unclear whether gas-aerosol partitioning should b...Thermodynamic modeling is still themostwidely usedmethod to characterize aerosol acidity,a critical physicochemical property of atmospheric aerosols.However,it remains unclear whether gas-aerosol partitioning should be incorporated when thermodynamicmodels are employed to estimate the acidity of coarse particles.In this work,field measurements were conducted at a coastal city in northern China across three seasons,and covered wide ranges of temperature,relative humidity and NH_(3) concentrations.We examined the performance of different modes of ISORROPIA-II(a widely used aerosol thermodynamic model)in estimating aerosol acidity of coarse and fine particles.The M0 mode,which incorporates gas-phase data and runs the model in the forward mode,provided reasonable estimation of aerosol acidity for coarse and fine particles.Compared to M0,the M1 mode,which runs the model in the forward mode but does not include gas-phase data,may capture the general trend of aerosol acidity but underestimates pH for both coarse and fine particles;M2,which runs the model in the reverse mode,results in large errors in estimated aerosol pH for both coarse and fine particles and should not be used for aerosol acidity calculations.However,M1 significantly underestimates liquid water contents for both fine and coarse particles,while M2 provides reliable estimation of liquid water contents.In summary,our work highlights the importance of incorporating gas-aerosol partitioning when estimating coarse particle acidity,and thus may help improve our understanding of acidity of coarse particles.展开更多
Silver paste is widely used in power electronics as a die-attach material owing to its low-temperature sinterability,high melting point,and excellent electrical and thermal conductivities in sintered joints.However,ow...Silver paste is widely used in power electronics as a die-attach material owing to its low-temperature sinterability,high melting point,and excellent electrical and thermal conductivities in sintered joints.However,owing to the mismatch in the coefficient of thermal expansion(CTE)between the joints and chip,the high Young's modulus of sintered silver hinders the mitigation of the high thermal stress generated during the operation of power modules,which increases the susceptibility of sintered joints to cracking,thereby leading to potential failure.This study developed a facile approach to synthesizing bayberry-like Ag microparticles(AgMPs)through the in situ assembly of silver nanorods,resulting in a uniform distribution of nanoscale structures and mesopores on the particle surface.These particles exhibited a high specific surface area of 2.5389 m^(2)·g^(-1),which enhanced theirsintering activity,enabling sintering to occur at 149.7℃.Furthermore,the porous structure of the AgMPs effectively reduced the density of joints formed by sintering AgMP paste,thereby lowering the Young's modulus of the joints.The small grain size and intricate internal substructure of the joints yielded high shear strength,which reached112.50 MPa at 250℃.The Young's modulus could be adjusted,and the pores provided by the AgMPs maintained the Young's modulus within a low range(15.11-29.61GPa),effectively mitigating thermal stress.These new bayberry-like porous AgMPs offer a promising option for die-attach materials in electronic packaging.展开更多
The development of efficient,cost-effective catalysts for the oxygen reduction reaction(ORR)is crucial for advancing zinc-air batteries(ZABs).This study presents Fe_(4)N nanoparticles embedded in N-doped carbon nanofi...The development of efficient,cost-effective catalysts for the oxygen reduction reaction(ORR)is crucial for advancing zinc-air batteries(ZABs).This study presents Fe_(4)N nanoparticles embedded in N-doped carbon nanofibers(Fe_(4)N@CNF-NH_(3))as a highly efficient ORR catalyst.The Fe_(4)N@CNF-NH_(3)catalyst was synthesized via electrospinning,followed by high-temperature annealing in an NH_(3)atmosphere.This electrospinning technique ensured the uniform dispersion of Fe_(4)N nanoparticles within the carbon nanofibers(CNFs),preventing agglomeration and enhancing the availability of active sites.Structural and morphological analyses confirmed the formation of Fe_(4)N nanoparticles with a lattice spacing of 0.213 nm,surrounded by graphitic carbon structures that significantly improved the material’s conductivity and stability.Electrochemical tests demonstrated that Fe_(4)N@CNF-NH_(3)exhibited superior ORR activity,with a half-wave potential of 0.904 V,surpassing that of commercial Pt/C catalysts.This enhanced performance is attributed to the synergistic effects of Fe_(4)N nanoparticles and the conductive carbon framework,which facilitated efficient charge and mass transfer during the ORR process.Density functional theory calculations further revealed that the introduction of CNFs positively shifted the d-band center of Fe atoms,optimizing oxygen intermediate adsorption and lowering energy barriers for ORR.The practical applicability of Fe_(4)N@CNF-NH_(3)was validated through the assembly of both liquid-state and solid-state ZABs,which exhibited excellent cycling stability,high power density,and superior discharge voltage.This study offers a promising strategy for developing highly active,low-cost ORR catalysts and advances the potential for the commercialization of ZABs.展开更多
Densely distributed coherent nanoparticles(DCN)in steel matrix can enhance the work-hardening ability and ductility of steel simultaneously.All the routes to this end can be generally classified into the liquid-solid ...Densely distributed coherent nanoparticles(DCN)in steel matrix can enhance the work-hardening ability and ductility of steel simultaneously.All the routes to this end can be generally classified into the liquid-solid route and the solid-solid route.However,the formation of DCN structures in steel requires long processes and complex steps.So far,obtaining steel with coherent particle enhancement in a short time remains a bottleneck,and some necessary steps remain unavoidable.Here,we show a high-efficiency liquid-phase refining process reinforced by a dynamic magnetic field.Ti-Y-Mn-O particles had an average size of around(3.53±1.21)nm and can be obtained in just around 180 s.These small nanoparticles were coherent with the matrix,implying no accumulated dislocations between the particles and the steel matrix.Our findings have a potential application for improving material machining capacity,creep resistance,and radiation resistance.展开更多
The morphological description of wear particles in lubricating oil is crucial for wear state monitoring and fault diagnosis in aero-engines.Accurately and comprehensively acquiring three-dimensional(3D)morphological d...The morphological description of wear particles in lubricating oil is crucial for wear state monitoring and fault diagnosis in aero-engines.Accurately and comprehensively acquiring three-dimensional(3D)morphological data of these particles has became a key focus in wear debris analysis.Herein,we develop a novel multi-view polarization-sensitive optical coherence tomography(PS-OCT)method to achieve accurate 3D morphology detection and reconstruction of aero-engine lubricant wear particles,effectively resolving occlusion-induced information loss while enabling material-specific characterization.The particle morphology is captured by multi-view imaging,followed by filtering,sharpening,and contour recognition.The method integrates advanced registration algorithms with Poisson reconstruction to generate high-precision 3D models.This approach not only provides accurate 3D morphological reconstruction but also mitigates information loss caused by particle occlusion,ensuring model completeness.Furthermore,by collecting polarization characteristics of typical metals and their oxides in aero-engine lubricants,this work comprehensively characterizes and comparatively analyzes particle polarization properties using Stokes vectors,polarization uniformity,and cumulative phase retardation,and obtains a three-dimensional model containing polarization information.Ultimately,the proposed method enables multidimensional information acquisition for the reliable identification of abrasive particle types.展开更多
Studying the contribution of regional transport to ultrafine particles(UFPs)and the deposition effect of nanoscale particles in human respiratory system is conducive to exploring the impact of atmospheric particles on...Studying the contribution of regional transport to ultrafine particles(UFPs)and the deposition effect of nanoscale particles in human respiratory system is conducive to exploring the impact of atmospheric particles on the environment and human health.Based on the data set of number concentration spectrum in the particle size range of 5.6–560 nm in the spring of Hefei,the Yangtze River Delta region obtained by a fast mobility particle sizer,the explosive growth characteristics,potential source identification and deposition flux analysis of UFPs were systematically studied.The results showed that the frequency of new particle formation(NPF)events during spring was 31.5%.SO_(2) and O_(3) contribute to NPF events.Daytime,higher temperature,stronger solar radiation and lower humidity were more conducive to the explosive growth of UFPs.In addition,regional transport of pollutants from the cities around Hefei played an important role in the accumulation mode particles,which were mainly affected by the land-source air mass from northwest Jiangsu(23.64%)and the sea-source air mass from the Yellow Sea(23.99%).It was worth noting that approximately 10,406 ng of UFPs enters the human respiratory system every day.Themain deposition area of 5.6–560 nm nanoscale particles was alveolar,5.6–400 nm is more likely to be deposited on alveolar,while nanoscale particles with particle size between 400 and 560 nm is more likely to be deposited on head airways.This study identified the deposition risk of nanoscale particles in the respiratory system under different particle sizes.展开更多
Aerosol particle pollution has become an increasing serious environmental problem,and urban vegetation plays a long-lasting and positive role in mitigating it.This study compared the particle capture abilities of tree...Aerosol particle pollution has become an increasing serious environmental problem,and urban vegetation plays a long-lasting and positive role in mitigating it.This study compared the particle capture abilities of trees,shrubs,and herbs,and examined the compositions and influence of aerosol particles accumulated on leaf functional traits.Retained particles primarily contained Ca^(2+),K^(+),SO_(4)^(2-),NO_(3)^(-)and NH_(4)^(+),indicating their anthropogenic origins.The leathery-leaved tree Osmanthus fragrans and the papery-leaved herb Alternanthera sessilis demonstrated the higher competence in particle accumulation than other plants,and leaf morphologic structures(e.g.,leaf grooves,trichomes,waxy layers,and stomata characteristics)were closely associated with particle capture by plant species.Particle retention negatively impacted stomata,impeding photosynthesis,and reducing transpiration.In response to particle accumulation,plants tended to decrease specific leaf area and adjust stomatal conductance.Both growth form and leaf texture significantly influenced the particle capture abilities of different plant species.The substantial contribution of plants,particularly herbs in the lower vegetation strata,to particle removal should not be overlooked.Vegetation with a tree-shrub-herb configuration excels at particle capture,offering potential advantages in mitigating particle pollution and enhancing ecological benefits.展开更多
Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ ...Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ measurements performed at a mountain site(1690 m a.s.l.)in southern China,we investigated the formation of NOCs in the cloud droplets and the cloud-free particles,based on their mixing state information of NOCscontaining particles by single particle mass spectrometry.The relative abundance of NOCs in the cloud-free particles was significantly higher than those in cloud residual(cloud RES)particles.NOCs were highly correlated with carbonyl compounds(including glyoxalate and methylglyoxal)in the cloud-free particles,however,limited correlation was observed for cloud RES particles.Analysis of their mixing state and temporal variations highlights that NOCs was mainly formed from the carbonyl compounds and ammonium in the cloud-free particles,rather than in the cloud RES particles.The results support that the formation of NOCs from carbonyl compounds is facilitated in concentrated solutions in wet aerosols,rather than cloud droplets.In addition,we have identified the transport of biomass burning particles that facilitate the formation of NOCs,and that the observed NOCs is most likely contributed to the light absorption.These findings have implications for the evaluation of NOCs formation and their contribution to light absorption.展开更多
1st error Within the abstract of the above paper,in the mathematical modeling,in Table 1 and in the concluding remarks,it is clearly mentioned that the base fluid in[1]is engine oil and ALL results have been produced ...1st error Within the abstract of the above paper,in the mathematical modeling,in Table 1 and in the concluding remarks,it is clearly mentioned that the base fluid in[1]is engine oil and ALL results have been produced for Prandtl number Pr=6.2.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.52373070,52273071 and U25A20255)the Special Support Plan for High-Level Talents in Zhejiang Province(No.2022R51008)the HZNU scientific research and innovation team project(No.TD2025004).
文摘Rubber-toughened thermoplastic materials have become ubiquitous in modern society owing to their lightweight nature and desirable combination of advantageous performances.Despite the ever-increasing demand,the development of polymer alloys that are lightweight,high-strength,and high-toughness remains an ongoing challenge.Inspired by the unique“salami”microstructure from commercial acrylonitrile butadiene styrene copolymer(ABS)and high-impact polystyrene(HIPS),a facile approach was developed to overcome the trade-off between enhancing the toughness and rigidity of fully polymer-based alloys by virtue of elastomeric salami particles.This strategy entails pre-grafting rigid poly(lactic acid)(PLLA)chains with glycidyl methacrylate-grafted octene ethylene copolymer(POE-g-GMA)using complementary reactive groups.It can be envisaged that the PLLA grafts featuring strong incompatibility with polypropylene(PP)remain fixed in elastomer phase upon the subsequent melt compounding,facilitating the in situ formation of“hard core(PLLA)-soft shell(polyolefin elastomer,POE)”particles in polypropylene(PP)matrix.The all-polymer alloys containing elastomeric salami particles demonstrated unprecedented performance combinations,including upper notched impact strengths(56.8 kJ/m2),even higher tensile strength(36.8 MPa),and Young’s modulus(0.93 GPa)than that of the PP matrix.Furthermore,these materials are lightweight without the incorporation of reinforcing nano-fillers,which is competitive with industrial engineering plastics.It is highly anticipated that this universal and highly efficient protocol will be appropriate for arbitrary rubber toughened/reinforced systems,offering a paradigm in the design of advanced all-polymer alloys.
基金supported by Sichuan Science and Technology Program(No.2024NSFSC0060)the National Natural Science Foundation of China(No.U23A2030)the Basic Research Cultivation Support Plan of Southwest Jiaotong University(No.2682023ZTPY016).
文摘Imidazole(IM)particles in the atmosphere affect climate,atmospheric chemical reactions,and human health.However,research on IM particles in the Sichuan Basin(SCB),one of the areas of China affected most heavily by haze,remains very scarce.This study used single-particle aerosol mass spectrometry to investigate IM-containing particles in Chengdu,one of the megacities in the SCB,during summer and winter before and after implemen-tation of the Three-year Action Plan to Win the Blue-Sky Defense War(BSDW).We found that IM-containing particles accounted for 1.2%–12.0%of all detected particles,and they highly mixed with carbonaceous com-ponents,secondary inorganic species,and organic nitrogen.From before to after the BSDW,the proportion of IM-containing particles decreased by 1.8%in summer,but increased by 9.6%in winter.Ammonium/amines and carbonyl compounds were closely related to IM-containing particles;the highest proportion of IM-containing particles occurred in particles mixed with amines and carbonyls.The number fraction of IM-containing particles in all seasons was higher at night than during daytime.The potential source areas of IM-containing particles showed notable narrowing after the BSDW,and the high-value areas were found distributed closer to Chengdu and its surrounding areas.In the winter before the BSDW,most IM-containing particles(>70%)were mixed with organic carbon(OC)particles,and the contributions of OC and mixed organic–elemental carbon(OC-EC)particles increased with aggravation of pollution,whereas OC-EC and Metal particles played a more crucial role in the winter after the BSDW.
基金supported by the National Natural Science Foundation of China(32071477,32272634).
文摘DealEdrtor,Dear Editor,Spodoptera litura,commonly known as the tobacco cutworm,is a polyphagous agricultural pest worldwide,causing significant economic losses to a wide range of crops.Over the past decades,S.litura has developed high resistance levels to multiple chemical insecticides(Li et al.,2024),and shown low susceptibility to transgenic Bacillus thuringiensis(Bt)cotton(Wan et al.,2008).
基金supported by the National Natural Science Foundation of China(Nos.81974441 and 82203619)the Science and Technology Planning Project of Shenzhen Municipality(Nos.JCYJ20190814105619048 and JCYJ20220530154202005)。
文摘Colitis-associated colorectal cancer(CAC)is a major contributor to cancer-related mortality worldwide.Titanium dioxide(TiO_(2),E171),a widely used food additive,has been insufficiently studied regarding its effects on macrophages within colon tumors during CAC development.In this study,CAC mouse models were used to investigate the biological impact of dietary E171 on macrophages in vivo,while lipopolysaccharide(LPS)-stimulated RAW264.7 macrophage cell lines were employed to elucidate the underlying mechanisms in vitro.We found that dietary E171 intake accelerated CAC development,exacerbated inflammatory responses and oxidative stress,and upregulated CAC-associated genes,including S100a8,S100a9,Lcn2,S100a11,Cxcl2,and interleukin-1α(Il-1α).E171 also increased the expression of S100A8,S100A9,NOD-like receptor family pyrin domain-containing 3(NLRP3),and gasdermin-D Nterminal(GSDMD-N)in macrophages within colon tumors.In inflammatory macrophages,E171 exposure enhanced cell viability,increased reactive oxygen species(ROS)levels,and elevated the expression and secretion of S100A8 and S100A9,consistent with in vivo histological observations.Furthermore,E171-induced secretion of S100A8 and S100A9 in macrophages was suppressed by specific inhibitors,including N-acetylcysteine(NAC,ROS inhibitor),MCC950(NLRP3 inhibitor),Z-YVAD-FMK(caspase 1 inhibitor),disulfiram(GSDMD inhibitor),and transfection of NLRP3 small interfering ribonucleic acid(siRNA).These results indicate that dietary E171 promotes CAC development by activating macrophages,with S100A8 and S100A9 serving as key mediators,and the NLRP3/caspase 1/GSDMD pathway acting as a critical mechanism.
基金supported by the Key Research and Development Program of Shandong Province(No.2021ZLGX01)Shanghai Kindly Medical Instrument Co.,Ltd。
文摘Rapid corrosion of magnesium alloys in the physiological environment limits their use as orthopedic implant materials.Therefore,the silane film modified with nano-hydroxyapatite(n HA)was prepared on the surface of AZ31 magnesium alloy to improve its corrosion resistance.The silane films are continuous,uniform,and adherent well to the Mg substrate,and the modification of the film by n HA increased the thickness from~1.92 to~3.25μm.Compared to the bare substrate,the corrosion current density of the sample with the silane film modified with n HA decreases by three orders of magnitude from 9.23×10^(-5)to 2.779×10^(-8)A/cm~2.According to the immersion tests,it is found that the synergistic effect of sub-film corrosion and blistering is the dominant mode of film failure.During the immersion of less than 72 h,the modification by n HA improves the corrosion resistance by delaying the sub-film corrosion and blistering of the film.
基金supported by the National Natural Science Foundation of China(Grant Nos.92252104,12388101,and 12472224).
文摘In this study,we perform particle-resolved simulations of settling spheroidal particles,considering oblate and prolate spheroids and spheres,and investigate the shape effect on the particle dynamics in suspensions with volume fraction 1%and 5%.We first examine the single-point statistics of the translational and rotational motion of the settling particles.The horizontal velocity has a symmetrical distribution with standard deviation dependent on the particle shape.The greater horizontal velocity fluctuations of the non-spherical particles,compared to that of spheres,are attributed to the horizontal drift of settling spheroids with oblique orientations induced by the fluid-particle and particle-particle interactions.The fluctuation of particle vertical velocity,instead,is skewed under the effect of wake-induced hydrodynamic interactions.Further,we explore the particle pair statistics,which demonstrate the formation of column-like particle micro-structures for the lowest volume fraction considered.This clustering is more pronounced for spheroidal particles than spheres,due to the stronger attractions among vertically-aligned settling spheroids.Moreover,the particle pair statistics are directly related to the collision rate among the dispersed particles.The local accumulation of oblate/prolate spheroids serves as the major mechanism to promote the particle-particle collisions in dilute suspensions.
基金supported by the National Natural Science Foundation of China(U2341288 and 12302492)。
文摘An in-depth understanding of the behaviours of solid propellants under low-velocity impact loads is crucial for enhancing their safety in applications such as aerospace propulsion.This study investigated the dynamic responses of single ammonium perchlorate(AP)/octogen(HMX)particles embedded in a hydroxyl-terminated polybutadiene(HTPB)binder under dynamic compression loading via real-time synchrotron-based X-ray phase contrast imaging and a modified split Hopkinson pressure bar(SHPB)system.The compression of the viscoelastic binder and subsequent dynamic fracturing of the AP/HMX particles were captured.During compression,transverse cracks developed within the AP particles,and their propagation led to particle fracturing,resulting in ductile fracturing.Unlike AP,HMX generated numerous short cracks within the internal and edge regions simultaneously,leading to fragmentation and brittle fracturing.Moreover,particle damage reduced the modulus of the sample,shifting its dynamic stress response from nonlinear elasticity to strain softening and further strain hardening as the binder exhibited plastic deformation.A compression simulation incorporating a real particle microscopic structure was established to study the mechanical response of the interface and particles.The simulation results agreed with the experimental observations.These results indicate that the shear stress at the HTPB-AP interface is greater than that at the HTPB-HMX interface,which is a factor influencing the differences in the mesoscale damage mechanisms of the particles.
基金supported by the National Natural Science Foundation of China under Grant No.12175198。
文摘We show that in Schwarzschild equivalent mediums,the massless spin particles obey the same dynamical equation,from which we obtain remarkably simple formulae for the frequencies of the quasibound states.We find that the quasibound frequencies of different bosons can be identical at the same quantum number l,and the same is true of different fermions,but a quasibound frequency for bosons can never equal a quasibound frequency for fermions.These results mean that in Schwarzschild equivalent mediums with the quasibound-state boundary conditions,characteristics of electromagnetic waves are the same as those for all the massless bosonic waves,thereby allowing electromagnetic waves to simulate gravitational waves.Our predictions can be tested in future experiments,building upon the successful preparation of Schwarzschild equivalent mediums.
文摘Although the strengthening and grain refinement effects of TiB_(2) particles on aluminum alloys have been extensively studied,their influence on casting behavior remains relatively underexplored.In this study,the influence of different addition amounts of submicron TiB_(2) particles on the microstructure,casting performance,and mechanical properties of an Al-Cu(ZL205A)alloy was systematically investigated.The introduction of TiB_(2) particles leads to significant grain refinement,transforming the microstructure from coarse grains to fine equiaxed grains by providing additional nucleation sites and inhibiting grain growth.SEM and TEM analyses reveal that the added submicron TiB_(2) particles exhibit minimal effect on the distribution of intermetallic phases or precipitates.Casting performance,as evaluated by spiral fluidity and hot tearing tests,shows notable improvements with TiB_(2) additions.At a TiB_(2) content of 3wt.%,the fluidity length increases by 20%,and the hot tearing susceptibility coefficient decreases by 29%.These enhancements are mainly due to the refined grain structure and the formation of interdendritic bridging in TiB_(2)-reinforced alloys.However,the overall enahncement in casting properties shows little variation across the TiB_(2) additions from 0.2wt.% to 3wt.%.Mechanical testing shows that the highest hardness and strength are achieved with a 1wt.%addition of TiB_(2) particles,primarily attributed to refined grain size and reinforcement of the aluminum matrix.Based on these findings,a TiB_(2) particle content of 1wt.%is recommended for optimizing both the casting performance and mechanical properties of the ZL205A alloy.
基金Project(2021YFC2801904)supported by the National Key R&D Program of ChinaProject(KY10100230067)supported by the Basic Product Innovation Research Project,China+3 种基金Projects(52271130,52305344)supported by the National Natural Science Foundation of ChinaProjects(ZR2020ME017,ZR2020QE186)supported by the Natural Science Foundation of Shandong Province,ChinaProjects(AMGM2024F11,AMGM2021F10,AMGM2023F06)supported by the Science Fund of Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai,ChinaProject(KY90200210015)supported by Leading Scientific Research Project of China National Nuclear Corporation(CNNC),China。
文摘WC particles reinforced CoCrFeNiMo high-entropy alloy(HEA)composite coatings were prepared on Cr12MoV steel successfully by laser cladding technology to improve the wear resistance of substrates.Effect of WC content on microstructure and wear property of the composite coatings was studied in detail.Large numbers of carbides with four main types:primary carbide crystals,eutectic structures,massive crystals growing along the periphery of the remaining WC particles and incompletely fused WC particles,were found to exist in the WC/CoCrFeNiMo composite coatings.With increasing WC content,the microhardness of coatings is gradually improved while the average friction coefficients follow the opposite trend due to solid solution strengthening and second phase strengthening effect.The maximum microhardness and minimum friction coefficient are HV_(0.2)689.7 and 0.72,respectively,for the composite coating with 30 wt.%WC,the wear resistance of the substrate is improved significantly,the wear mechanisms are spalling wear and abrasive wear due to their high microhardness.
基金supported by the National Key Research and Development Program of China(No.2019YFC1804202)the National Natural Science Foundation of China(Nos.22020102004 and 22125603)+1 种基金Tianjin Municipal Science and Technology Bureau(No.21JCZDJC00280)the Fundamental Research Funds for the Central Universities,and the Ministry of Education of China(No.T2017002).
文摘Polybrominated biphenyl ethers(PBDEs)and polycyclic aromatic hydrocarbons(PAHs)are commonly detected contaminants at e-waste recycling sites.Against the conventional wisdom that PBDEs and PAHs are highly immobile and persist primarily in shallowsurface soils,increasing evidence shows that these compounds can leach into the groundwater.Herein,we compare the leachabilities of PBDEs vs.PAHs from contaminated soils collected at an e-waste recycling site in Tianjin,China.Considerable amounts of BDE-209(0.3–2 ng/L)and phenanthrene(42–106 ng/L),the most abundant PBDE and PAH at the site,are detected in the effluents of columns packed with contaminated soils,with the specific concentrations varying with hydrodynamic and solution chemistry conditions.Interestingly,the leaching potential of BDE-209 appears to be closely related to the release of colloidal mineral particles,whereas the leachability of phenanthrene correlates well with the concentration of dissolved organic carbon in the effluent,but showing essentially no correlation with the concentration of mineral particles.The surprisingly different trends of the leachability observed between BDE-209 and phenanthrene is counterintuitive,as PBDEs and PAHs often co-exist at e-waste recycling sites(particularly at the sites wherein incineration is being practiced)and share many similarities in terms of physicochemical properties.One possible explanation is that due to its extremely low solubility,BDE-209 predominantly exists in free-phase(i.e.,as solid(nano)particles),whereas the more soluble phenanthrene is mainly sorbed to soil organic matter.Findings in this study underscore the need to better understand the mobility of highly hydrophobic organic contaminants at contaminated sites for improved risk management.
基金supported by the National Natural Science Foundation of China (Nos.42022050 and 42277088)the Guangdong Basic and Applied Basic Research Fund Committee (Nos.2021A1515011248 and 2023A1515012010)the Guangdong Foundation for the Program of Science and Technology Research (No.2020B1212060053).
文摘Thermodynamic modeling is still themostwidely usedmethod to characterize aerosol acidity,a critical physicochemical property of atmospheric aerosols.However,it remains unclear whether gas-aerosol partitioning should be incorporated when thermodynamicmodels are employed to estimate the acidity of coarse particles.In this work,field measurements were conducted at a coastal city in northern China across three seasons,and covered wide ranges of temperature,relative humidity and NH_(3) concentrations.We examined the performance of different modes of ISORROPIA-II(a widely used aerosol thermodynamic model)in estimating aerosol acidity of coarse and fine particles.The M0 mode,which incorporates gas-phase data and runs the model in the forward mode,provided reasonable estimation of aerosol acidity for coarse and fine particles.Compared to M0,the M1 mode,which runs the model in the forward mode but does not include gas-phase data,may capture the general trend of aerosol acidity but underestimates pH for both coarse and fine particles;M2,which runs the model in the reverse mode,results in large errors in estimated aerosol pH for both coarse and fine particles and should not be used for aerosol acidity calculations.However,M1 significantly underestimates liquid water contents for both fine and coarse particles,while M2 provides reliable estimation of liquid water contents.In summary,our work highlights the importance of incorporating gas-aerosol partitioning when estimating coarse particle acidity,and thus may help improve our understanding of acidity of coarse particles.
基金financially supported by the National Natural Science Foundation of China(Nos.52075125 and 52105331)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515010591)Shenzhen Science and Technology Innovation Committee(Nos.JCYJ20210324124203009,JSGG20201102154600003,GXWD20231130103814001,GXWD20220721182229001)
文摘Silver paste is widely used in power electronics as a die-attach material owing to its low-temperature sinterability,high melting point,and excellent electrical and thermal conductivities in sintered joints.However,owing to the mismatch in the coefficient of thermal expansion(CTE)between the joints and chip,the high Young's modulus of sintered silver hinders the mitigation of the high thermal stress generated during the operation of power modules,which increases the susceptibility of sintered joints to cracking,thereby leading to potential failure.This study developed a facile approach to synthesizing bayberry-like Ag microparticles(AgMPs)through the in situ assembly of silver nanorods,resulting in a uniform distribution of nanoscale structures and mesopores on the particle surface.These particles exhibited a high specific surface area of 2.5389 m^(2)·g^(-1),which enhanced theirsintering activity,enabling sintering to occur at 149.7℃.Furthermore,the porous structure of the AgMPs effectively reduced the density of joints formed by sintering AgMP paste,thereby lowering the Young's modulus of the joints.The small grain size and intricate internal substructure of the joints yielded high shear strength,which reached112.50 MPa at 250℃.The Young's modulus could be adjusted,and the pores provided by the AgMPs maintained the Young's modulus within a low range(15.11-29.61GPa),effectively mitigating thermal stress.These new bayberry-like porous AgMPs offer a promising option for die-attach materials in electronic packaging.
基金supported by the National Natural Science Foundation of China(No.11904208the Project of Shandong Province Higher Educational Science and Technology Program(No.J18KB098).
文摘The development of efficient,cost-effective catalysts for the oxygen reduction reaction(ORR)is crucial for advancing zinc-air batteries(ZABs).This study presents Fe_(4)N nanoparticles embedded in N-doped carbon nanofibers(Fe_(4)N@CNF-NH_(3))as a highly efficient ORR catalyst.The Fe_(4)N@CNF-NH_(3)catalyst was synthesized via electrospinning,followed by high-temperature annealing in an NH_(3)atmosphere.This electrospinning technique ensured the uniform dispersion of Fe_(4)N nanoparticles within the carbon nanofibers(CNFs),preventing agglomeration and enhancing the availability of active sites.Structural and morphological analyses confirmed the formation of Fe_(4)N nanoparticles with a lattice spacing of 0.213 nm,surrounded by graphitic carbon structures that significantly improved the material’s conductivity and stability.Electrochemical tests demonstrated that Fe_(4)N@CNF-NH_(3)exhibited superior ORR activity,with a half-wave potential of 0.904 V,surpassing that of commercial Pt/C catalysts.This enhanced performance is attributed to the synergistic effects of Fe_(4)N nanoparticles and the conductive carbon framework,which facilitated efficient charge and mass transfer during the ORR process.Density functional theory calculations further revealed that the introduction of CNFs positively shifted the d-band center of Fe atoms,optimizing oxygen intermediate adsorption and lowering energy barriers for ORR.The practical applicability of Fe_(4)N@CNF-NH_(3)was validated through the assembly of both liquid-state and solid-state ZABs,which exhibited excellent cycling stability,high power density,and superior discharge voltage.This study offers a promising strategy for developing highly active,low-cost ORR catalysts and advances the potential for the commercialization of ZABs.
基金financially supported by the National Natural Science Foundation of China(No.51771125)the Sichuan Province Science and Technology Support Program(No.2020YFG0102)。
文摘Densely distributed coherent nanoparticles(DCN)in steel matrix can enhance the work-hardening ability and ductility of steel simultaneously.All the routes to this end can be generally classified into the liquid-solid route and the solid-solid route.However,the formation of DCN structures in steel requires long processes and complex steps.So far,obtaining steel with coherent particle enhancement in a short time remains a bottleneck,and some necessary steps remain unavoidable.Here,we show a high-efficiency liquid-phase refining process reinforced by a dynamic magnetic field.Ti-Y-Mn-O particles had an average size of around(3.53±1.21)nm and can be obtained in just around 180 s.These small nanoparticles were coherent with the matrix,implying no accumulated dislocations between the particles and the steel matrix.Our findings have a potential application for improving material machining capacity,creep resistance,and radiation resistance.
文摘The morphological description of wear particles in lubricating oil is crucial for wear state monitoring and fault diagnosis in aero-engines.Accurately and comprehensively acquiring three-dimensional(3D)morphological data of these particles has became a key focus in wear debris analysis.Herein,we develop a novel multi-view polarization-sensitive optical coherence tomography(PS-OCT)method to achieve accurate 3D morphology detection and reconstruction of aero-engine lubricant wear particles,effectively resolving occlusion-induced information loss while enabling material-specific characterization.The particle morphology is captured by multi-view imaging,followed by filtering,sharpening,and contour recognition.The method integrates advanced registration algorithms with Poisson reconstruction to generate high-precision 3D models.This approach not only provides accurate 3D morphological reconstruction but also mitigates information loss caused by particle occlusion,ensuring model completeness.Furthermore,by collecting polarization characteristics of typical metals and their oxides in aero-engine lubricants,this work comprehensively characterizes and comparatively analyzes particle polarization properties using Stokes vectors,polarization uniformity,and cumulative phase retardation,and obtains a three-dimensional model containing polarization information.Ultimately,the proposed method enables multidimensional information acquisition for the reliable identification of abrasive particle types.
基金supported by the National Natural Science Foundation of China(Nos.U21A2027,42207113,and 42407141)。
文摘Studying the contribution of regional transport to ultrafine particles(UFPs)and the deposition effect of nanoscale particles in human respiratory system is conducive to exploring the impact of atmospheric particles on the environment and human health.Based on the data set of number concentration spectrum in the particle size range of 5.6–560 nm in the spring of Hefei,the Yangtze River Delta region obtained by a fast mobility particle sizer,the explosive growth characteristics,potential source identification and deposition flux analysis of UFPs were systematically studied.The results showed that the frequency of new particle formation(NPF)events during spring was 31.5%.SO_(2) and O_(3) contribute to NPF events.Daytime,higher temperature,stronger solar radiation and lower humidity were more conducive to the explosive growth of UFPs.In addition,regional transport of pollutants from the cities around Hefei played an important role in the accumulation mode particles,which were mainly affected by the land-source air mass from northwest Jiangsu(23.64%)and the sea-source air mass from the Yellow Sea(23.99%).It was worth noting that approximately 10,406 ng of UFPs enters the human respiratory system every day.Themain deposition area of 5.6–560 nm nanoscale particles was alveolar,5.6–400 nm is more likely to be deposited on alveolar,while nanoscale particles with particle size between 400 and 560 nm is more likely to be deposited on head airways.This study identified the deposition risk of nanoscale particles in the respiratory system under different particle sizes.
基金supported by the National Natural Science Foundation of China(No.31700475).
文摘Aerosol particle pollution has become an increasing serious environmental problem,and urban vegetation plays a long-lasting and positive role in mitigating it.This study compared the particle capture abilities of trees,shrubs,and herbs,and examined the compositions and influence of aerosol particles accumulated on leaf functional traits.Retained particles primarily contained Ca^(2+),K^(+),SO_(4)^(2-),NO_(3)^(-)and NH_(4)^(+),indicating their anthropogenic origins.The leathery-leaved tree Osmanthus fragrans and the papery-leaved herb Alternanthera sessilis demonstrated the higher competence in particle accumulation than other plants,and leaf morphologic structures(e.g.,leaf grooves,trichomes,waxy layers,and stomata characteristics)were closely associated with particle capture by plant species.Particle retention negatively impacted stomata,impeding photosynthesis,and reducing transpiration.In response to particle accumulation,plants tended to decrease specific leaf area and adjust stomatal conductance.Both growth form and leaf texture significantly influenced the particle capture abilities of different plant species.The substantial contribution of plants,particularly herbs in the lower vegetation strata,to particle removal should not be overlooked.Vegetation with a tree-shrub-herb configuration excels at particle capture,offering potential advantages in mitigating particle pollution and enhancing ecological benefits.
基金supported by the National Key Research and Development Program of China(No.2022YFC3701103)the National Natural Science Foundation of China(No.42222705)+1 种基金the Youth Innovation Promotion Association CAS(No.2021354)Guangdong Foundation for Program of Science and Technology Research(No.2023B1212060049).
文摘Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ measurements performed at a mountain site(1690 m a.s.l.)in southern China,we investigated the formation of NOCs in the cloud droplets and the cloud-free particles,based on their mixing state information of NOCscontaining particles by single particle mass spectrometry.The relative abundance of NOCs in the cloud-free particles was significantly higher than those in cloud residual(cloud RES)particles.NOCs were highly correlated with carbonyl compounds(including glyoxalate and methylglyoxal)in the cloud-free particles,however,limited correlation was observed for cloud RES particles.Analysis of their mixing state and temporal variations highlights that NOCs was mainly formed from the carbonyl compounds and ammonium in the cloud-free particles,rather than in the cloud RES particles.The results support that the formation of NOCs from carbonyl compounds is facilitated in concentrated solutions in wet aerosols,rather than cloud droplets.In addition,we have identified the transport of biomass burning particles that facilitate the formation of NOCs,and that the observed NOCs is most likely contributed to the light absorption.These findings have implications for the evaluation of NOCs formation and their contribution to light absorption.
文摘1st error Within the abstract of the above paper,in the mathematical modeling,in Table 1 and in the concluding remarks,it is clearly mentioned that the base fluid in[1]is engine oil and ALL results have been produced for Prandtl number Pr=6.2.
