In response to the urgent demand for lightweight,magnesium(Mg)alloys have garnered considerable attention owing to their low density.Nonetheless,the intrinsic poor room-temperature formability of Mg alloys remains a m...In response to the urgent demand for lightweight,magnesium(Mg)alloys have garnered considerable attention owing to their low density.Nonetheless,the intrinsic poor room-temperature formability of Mg alloys remains a major obstacle in shaping precise complex components,necessitating the development of superplastic Mg alloys.Excellent superplasticity is usually acquired in high-alloyed Mg alloys with enhanced microstructural thermal stability facilitated by abundant optimized second-phase particles.While for cost-effective low-alloyed Mg alloys lacking particles,regulating solute segregation has emerged as a promising approach to achieve superplasticity recently.Moreover,the potential of bimodal-grained Mg alloys for superplastic deformation has been revealed,expanding the options for designing superplastic materials beyond the conventional approach of fine-grained microstructures.This study reviews significant developments in superplastic Mg alloys from the view of alloying strategies,grain structure control and deformation mechanisms,with potential implications for future research and industrial applications of superplastic Mg alloys.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
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
Autologous bone marrow-derived mesenchymal stem cells(BMSCs)have been shown to promote osteogenesis;however,the effects of allogeneic BMSCs(allo-BMSCs)on bone regeneration remain unclear.Therefore,we explored the bone...Autologous bone marrow-derived mesenchymal stem cells(BMSCs)have been shown to promote osteogenesis;however,the effects of allogeneic BMSCs(allo-BMSCs)on bone regeneration remain unclear.Therefore,we explored the bone regeneration promotion effect of allo-BMSCs in 3D-printed autologous bone particle(ABP)scaffolds.First,we concurrently printed scaffolds with polycaprolactone,ABPs,and allo-BMSCs for appropriate support,providing bioactive factors and seed cells to promote osteogenesis.In vitro studies showed that ABP scaffolds promoted allo-BMSC osteogenic differentiation.In vivo studies revealed that the implantation of scaffolds loaded with ABPs and allo-BMSCs into canine skull defects for nine months promoted osteogenesis.Further experiments suggested that only a small portion of implanted allo-BMSCs survived and differentiated into vascular endothelial cells,chondrocytes,and osteocytes.The implanted allo-BMSCs released stromal cell-derived factor 1 through paracrine signaling to recruit native BMSCs into the defect,promoting bone regeneration.This study contributes to our understanding of allo-BMSCs,providing information relevant to their future application.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
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
The environmental magnetic proxies of stalagmites hold significant potential for reconstructing regional hydroclimate changes by revealing the content and grain size of magnetic particles within stalagmites.In this st...The environmental magnetic proxies of stalagmites hold significant potential for reconstructing regional hydroclimate changes by revealing the content and grain size of magnetic particles within stalagmites.In this study,we present the contents and grain sizes of magnetic particles within a stalagmite SZ-1,from Shizhu Cave in southwestern China from 70.4 to 22.3 thousand years ago(ka)during the last glacial period.Specifically,the parameters IRM_(soft),soil-derived magnetic minerals,and ARM/SIRM(anhysteretic remanent magnetization/saturation isothermal remanent magnetization),the ratio of fine magnetic particles to total ferrimagnetic particles preserved in stalagmite SZ-1,indicate the fluctuation of regional precipitation.Obvious half-precessional cycles are evident in these two proxies,indicating that hydroclimatic variations in southwestern China may predominantly arise from the heat and moisture transported from tropical oceans.These variations are likely influenced by shifts in the Intertropical Convergence Zone and fluctuations in the Asian Summer Monsoon.展开更多
The ongoing operation of subway systems makes existing tunnels vulnerable to deformations and structural damage caused by adjacent foundation pit construction.Such deformations-manifesting as horizontal displacement,h...The ongoing operation of subway systems makes existing tunnels vulnerable to deformations and structural damage caused by adjacent foundation pit construction.Such deformations-manifesting as horizontal displacement,heightened lateral convergence,and internal force redistribution-may significantly compromise subway operational safety.Grouting remediation has become a widely adopted solution for tunnel deformation control and structural reinforcement.Developing optimized grouting materials is crucial for improving remediation effectiveness,ensuring structural integrity,and maintaining uninterrupted subway operations.This investigation explores the substitution of fine mortar aggregates with 0.1 mm discarded rubber particles at varying concentrations(0%,3%,6%,9%,12%,and 15%).Experimental parameters included three water-cement ratios(0.65,0.70,and 0.75)with constant 4%WPU content.Mechanical properties including compressive strength,flexural strength,and compression-to-bending ratio were evaluated across specified curing periods.Material characterization employed Fourier Transform Infrared Spectroscopy(FTIR)spectroscopy for molecular analysis and Scanning Electron Microscopy(SEM)for microstructural examination.Results indicate optimal toughness at 0.70 water-cement ratio with 6%rubber content,meeting mechanical pumping specifications while maintaining structural performance.展开更多
Triboelectric nanogenerators(TENGs)are emerging as new technologies to harvest electrical power from mechanical energy.With the distinctive working mechanism of triboelectric nanogenerators,they attract particular int...Triboelectric nanogenerators(TENGs)are emerging as new technologies to harvest electrical power from mechanical energy.With the distinctive working mechanism of triboelectric nanogenerators,they attract particular interest in healthcare monitoring,wearable electronics,and deformable energy harvesting,which raises the requirement for highly conformable devices with substantial energy outputs.Here,a simple,low-cost strategy for fabricating stretchable triboelectric nanogenerators with ultra-high electrical output is developed.The TENG is prepared using PTFE micron particles(PPTENG),contributing a different electrostatic induction process compared to TENG based on dielectric films,which was associated with the dynamics of particle motions in PP-TENG.The generator achieved an impressive voltage output of 1000 V with a current of 25 lA over a contact area of 40320 mm^(2).Additionally,the TENG exhibits excellent durability with a stretching strain of 500%,and the electrical output performance does not show any significant degradation even after 3000 cycles at a strain of 400%.The unique design of the device provides high conformability and can be used as a self-powered sensor for human motion detection.展开更多
The effect of intermetallic particles on the corrosion of 6061 aluminum alloy and its coating used in semiconductor processing systems was systematically studied via liquid and gas experiments and micromorphology char...The effect of intermetallic particles on the corrosion of 6061 aluminum alloy and its coating used in semiconductor processing systems was systematically studied via liquid and gas experiments and micromorphology characterization.The results revealed that a huge difference of corrosion resistance between imported and domestic 6061 aluminum alloys in HCl solution and gas acid mist experiments mainly was attributed to the different size and amount of Al_(15)(Fe,Mn)_(3)Si_(2).The corrosion resistance of domestic 6061 alloy in dry/wet semiconductor electronic special gas environments was worse than that of imported aluminum alloy,and there are great differences in the corrosion mechanism of 6061 alloy caused by the second phase in the two dry/wet environments.And the corrosion resistance of the hard anodized alumina film was closely related to the microscopic morphology of holes.The vertical and elongatedα-Al_(15)(Mn,Fe)_(3)Si_(2) phase was formed in the rolled aluminum alloy that has been rolled perpendicular to the surface of the substrate.Compared to the horizontal long hole,the longitudinal long holes generated by the verticalα-Al_(15)(Mn,Fe)_(3)Si_(2) phase will enable the corrosive medium to reach the substrate rapidly,which significantly weakens the corrosion resistance of the hard anodized film.展开更多
Herein,we fabricate an embedding structure at the interface between Pt nanoparticles(NPs)and CeO_(2)-{100}nanocubes with surface defect sites(CeO_(2)-SDS)through quenching and gas bubbling-assisted membrane reduction ...Herein,we fabricate an embedding structure at the interface between Pt nanoparticles(NPs)and CeO_(2)-{100}nanocubes with surface defect sites(CeO_(2)-SDS)through quenching and gas bubbling-assisted membrane reduction methods.The in-situ substitution of Pt NPs for atomic-layer Ce lattice significantly increases the amount of reactive oxygen species from 133.68μmol/g to 199.44μmol/g.As a result,the distinctive geometric structure of Pt/CeO_(2)-SDS catalyst substantially improves the catalytic activity and stability for soot oxidation compared with the catalyst with no quenching process,i.e.,its T_(50)and TOF values are 332°C and 2.915 h^(-1),respectively.Combined with the results of experimental investigations and density functional theory calculations,it is unveiled that the unique embedding structure of Pt/CeO_(2)-SDS catalyst can facilitate significantly electron transfer from Pt to the CeO_(2)-{100}support,and induce the formation of interfacial[Ce-O_(x)-Pt_(2)]bond chains,which plays a crucial role in enhancing the key step of soot oxidation through the dual activation of surface lattice oxygen and molecular O_(2).Such a fundamental revelation of the interfacial electronic transmission and corresponding modification strategy contributes a novel opportunity to develop high-efficient and stable noble metal catalysts at the atomic level.展开更多
This study analyzes fast ion losses in the EHL-2 fusion device,focusing on both beam ions and alpha particles as p-11B fusion reaction products.Using the Monte Carlo orbit-following code TGCO,we evaluate particle conf...This study analyzes fast ion losses in the EHL-2 fusion device,focusing on both beam ions and alpha particles as p-11B fusion reaction products.Using the Monte Carlo orbit-following code TGCO,we evaluate particle confinement under various operational scenarios,including co-injected tangential neutral beam injection at beam energies of 60 keV,80 keV,and 200 keV.Our simulations estimate the heat load driven by lost beam ions and find it to be within acceptable material limits for a plasma current on the order of mega-amperes.Additionally,we simulate the distribution of fusion products and observe a higher particle loss fraction for alpha particles compared to beam ions.However,due to the relatively low fusion power,these lost alpha particles are unlikely to significantly impact the plasma-facing materials.To assess the impact of the magnetic ripple,we compute the ripple field distribution by modelling the toroidal field(TF)coils as current filaments.The results indicate that the ripple field effect on particle confinement is minimal,primarily due to the large distance of over 1 m between the TF coils and the plasma on the low-field side.The analysis based on the test particle model is a foundational step in ensuring the basic safety aspects of the new device,which is essential for developing a robust design,optimizing performance,and maintaining safe operation.展开更多
Significant differences exist in the elliptic flowυ2 for particles and their corresponding anti-particles.These differences,which are more significant for baryons and anti-baryons,were observed from the solenoidal tr...Significant differences exist in the elliptic flowυ2 for particles and their corresponding anti-particles.These differences,which are more significant for baryons and anti-baryons,were observed from the solenoidal tracker(STAR)experiment during Beam Energy Scan I(BES-I)at relativistic heavy ion collider(RHIC).By employing the simulated many-accelerated strongly interacting hadrons(SMASH)model,we studied the ν_(2) differences between protons and anti-protons as well as between ∧ and ∧^(-)in Au+Au collisions at √S_(NN)=7.7 GeV as a function of the evolution time.It was found that as the evolution time increases,the𝑣2 differences between protons and anti-protons become more significant than those between ∧ and ∧^(-).This phenomenon can be explained by the different constituent quarks of protons and ∧.Given that some of the𝑢and𝑑quarks come from the colliding nuclei and are transported to midrapidity,they undergo more interactions than the produced quarks,resulting in protons Δν_(2) being larger than ∧Δν_(2).We compared the SMASH calculations with STAR BES-Ⅰ data and concluded that higher-precision data from BES-Ⅱ will set constraints on theoretical frameworks to interpret the ν_(2) differences between particles and anti-particles.展开更多
Accurately acquiring catalyst size and morphology is essential for supporting catalytic reaction process design and optimal control. We report an intelligent catalyst sizing and morphological classification method bas...Accurately acquiring catalyst size and morphology is essential for supporting catalytic reaction process design and optimal control. We report an intelligent catalyst sizing and morphological classification method based on the Mask-RCNN framework. A dataset of 9880 high-resolution images was captured by using a self-made fiber-optic endoscopic system for 13 kinds of silicoaluminophosphate-34 (SAPO-34) catalyst samples with different coke. Then there were approximately 877881 individual particles extracted from this dataset by our AI-based particle recognition algorithm. To clearly describe the morphology of irregular particles, we proposed a hybrid classification criterion that combines five different parameters, which are deformity, circularity, roundness, aspect ratio, and compactness. Therefore, catalyst morphology can be classified into two categories with four types. The first category includes regular types, such as the spherical, ellipsoidal, and rod-shaped types. And all the irregular types fall into the second category. The experimental results showed that a catalyst particle tends to be larger when its coke deposition increased. Whereas particle morphology remained primarily spherical and ellipsoidal, the ratio of each type varied slightly according to its coke. Our findings illustrate that this is a promising approach to be developing intelligent instruments for catalyst particle sizing and classification.展开更多
A type of novel biodegradable fibers,made from magnetic particles and the patient’s own blood,promises an immune-evading brain cancer therapy with minimal invasion.
In the present study,we concentrate on finding the dual solutions of biomagnetic fluid namely blood flow and heat transfer along with magnetic particles over a two dimensional shrinking cylinder in the presence of a m...In the present study,we concentrate on finding the dual solutions of biomagnetic fluid namely blood flow and heat transfer along with magnetic particles over a two dimensional shrinking cylinder in the presence of a magnetic dipole.To make the results physically realistic,stability analysis is also carried out in this study so that we realized which solution is stable and which is not.The governing partial equations are converted into ordinary differential equations by using similarity transformations and the numerical solution is calculated by applying bvp4c function technique in MATLAB software.The effects of different physical parameters are plotted graphically and discussed according to the outcomes of results.From the present study we observe that ferromagnetic interaction parameter had a great influenced on fluid velocity and temperature distributions.It is also found from the current analysis that the first and second solutions of shrinking cylinder obtained only when we applied particular ranges values of suction parameter.The most important characteristics part of study is to analyze the skin friction coefficient and rate of heat transfer which also covered in this analysis.It reveals that both skin friction coefficient and rate of heat transfer are reduced with rising values of ferromagnetic number.A comparison has also been made to make the solution feasible.展开更多
Atmospheric metal pollution is a significant environmental issue in China.Understanding the microscopic characteristics of metallic elements are crucial for investigating their sources and health effects,but this info...Atmospheric metal pollution is a significant environmental issue in China.Understanding the microscopic characteristics of metallic elements are crucial for investigating their sources and health effects,but this information is still limited.In this study,transmission electron microscopy(TEM)combined with bulk analysis method were employed to investigate the microscopic characteristics and mass concentrations of atmospheric metallic elements at a village site and an urban site located in North China Plain during wintertime.Our results reveal that the total mass concentrations of 16 metallic elements(including nine toxic heavy metallic elements)in PM_(2.5)were 3439.18±1101.24 ng/m^(3)(1129.6±376.85 ng/m^(3))at the village site and 3555.1±916.71 ng/m^(3)(1295.26±446.39 ng/m^(3))at urban site,accounting for 2.23%and 2.76%of PM_(2.5),respectively.We found that K,Ca,and Fe were the dominant elements,constituting over 75%of total metal mass.TEM analysis indicates that these metallic elements were mainly enriched in six types of individual particles,including K-rich,mineral,fly ash,Fe-rich,Zn-rich,and Pb-rich particles.Mineral particles were predominant in all individual metal particles at urban site,while K-rich particles became the dominant metal particles influenced by residential biomass burning at village site.Moreover,we found toxic metal particles(Fe-rich,Zn-rich,Pb-rich,and fly ash)presented smaller mean sizes(243 nm)in village air compared to urban air(337 nm),suggesting that metal particles in village air might pose a higher health risk to the residents.These results emphasize that atmospheric metal pollution in the village areas need more attentions in the future.展开更多
Quantum entanglement is a bizarre, counterintuitive phenomenon which shows that entangled subatomic particles remain related even when they are far apart, which was described by Einstein as “spooky action at a dista...Quantum entanglement is a bizarre, counterintuitive phenomenon which shows that entangled subatomic particles remain related even when they are far apart, which was described by Einstein as “spooky action at a distance”. Although this phenomenon could be interpreted by a few theories, for example, the famous Copenhagen interpretation which describes that these states exist simultaneously by a wave function, however, there is still no unquestioned theory and it continues to puzzle people around the world. Here we propose a hypothesis that gravity cuts out stop functioning between subatomic particles based on the observations of a thought experiment. It is well known that the Universe is filled with various subatomic particles (e.g. cosmic neutrino background, CνB) and gravity is a universal force making any particle in the Universe attract any other. Based on these observations, it is expected that the CνB particles walking abreast will be combined together by their gravity after some time/distance, which will thus result in a greatly uneven distribution of CνB. However, the observational evidence showed that CνB is highly isotropic and homogenous, suggesting that gravity would no longer work at the subatomic scale. Thus, the relation of the paired subatomic particles would become some pure correlation of mass (or equivalent energy) status. In this case, time would be not required anymore due to the ineffectiveness of gravity. The proposed new interpretation matches the experimental observations well and finally possible thought experiments are presented to test this theory.展开更多
The strength improvement in the heat-treatable Al-Zn-Mg-Cu alloys is generally achieved by increasing the volume fraction of nanoprecipitates and reducing the grain size.However,utilizing one of them usu-ally leads to...The strength improvement in the heat-treatable Al-Zn-Mg-Cu alloys is generally achieved by increasing the volume fraction of nanoprecipitates and reducing the grain size.However,utilizing one of them usu-ally leads to a drastic decrease in ductility.Herein,we architect a hierarchical microstructure integrating bimodal grain structures,nanoprecipitates,and hard-brittle coarse particles wrapped by ductility coarse grain(CG)bands via conventional cold rolling(CR)deformation and heat treatment methods to break the strength-ductility dilemma in the Al-8.89Zn-1.98Mg-2.06Cu-0.12Zr-0.05Sc-0.05Hf(wt.%)alloy.The results reveal that the coupling of high-volume fraction(∼1.2%)nanoprecipitates,∼52%narrow CG bands,and most coarse particles encapsulated by CG bands contribute to the 45%CR sample with outstanding over-all mechanical properties(a tensile strength of 655 MPa,a yield strength of 620 MPa,and an elongation of 15.5%).Microstructure-based strength analysis confirms that the high strength relates to a trade-offbetween the hierarchical features,namely high-volume fraction nanoprecipitates to counterbalance the strength loss caused by grain coarsening.The excellent ductility is due to the introduction of medium CG content with a narrow width that can trigger a cross-scale strain distribution during plastic deforma-tion,suppressing the catastrophic failure in the fine grain(FG)regions and facilitating the dimple fracture along the CG bands.This study proposes a feasible approach for tailoring hierarchical microstructures in Al-Zn-Mg-Cu alloys to achieve a superior strength-ductility combination.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
基金primarily supported by The National Natural Science Foundation of China(under Nos.52234009 and 52271103)Partial financial support came from the Program for the Central University Youth Innovation Team(No.419021423505)the Fundamental Research Funds for the Central Universities,JLU.
文摘In response to the urgent demand for lightweight,magnesium(Mg)alloys have garnered considerable attention owing to their low density.Nonetheless,the intrinsic poor room-temperature formability of Mg alloys remains a major obstacle in shaping precise complex components,necessitating the development of superplastic Mg alloys.Excellent superplasticity is usually acquired in high-alloyed Mg alloys with enhanced microstructural thermal stability facilitated by abundant optimized second-phase particles.While for cost-effective low-alloyed Mg alloys lacking particles,regulating solute segregation has emerged as a promising approach to achieve superplasticity recently.Moreover,the potential of bimodal-grained Mg alloys for superplastic deformation has been revealed,expanding the options for designing superplastic materials beyond the conventional approach of fine-grained microstructures.This study reviews significant developments in superplastic Mg alloys from the view of alloying strategies,grain structure control and deformation mechanisms,with potential implications for future research and industrial applications of superplastic Mg alloys.
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 Science and Technology Development Fund of the Fourth Military Medical University(No.2016XB051)the Military Medical Promotion Plan of the Fourth Military Medical University(No.2016TSA-005)+2 种基金the Science and Technology Program of Guangzhou(No.201604040002)the Youth Development Project of Air Force Medical University(No.21QNPY072)the Xijing Hospital Booster Program(No.XJZT24CZ10).
文摘Autologous bone marrow-derived mesenchymal stem cells(BMSCs)have been shown to promote osteogenesis;however,the effects of allogeneic BMSCs(allo-BMSCs)on bone regeneration remain unclear.Therefore,we explored the bone regeneration promotion effect of allo-BMSCs in 3D-printed autologous bone particle(ABP)scaffolds.First,we concurrently printed scaffolds with polycaprolactone,ABPs,and allo-BMSCs for appropriate support,providing bioactive factors and seed cells to promote osteogenesis.In vitro studies showed that ABP scaffolds promoted allo-BMSC osteogenic differentiation.In vivo studies revealed that the implantation of scaffolds loaded with ABPs and allo-BMSCs into canine skull defects for nine months promoted osteogenesis.Further experiments suggested that only a small portion of implanted allo-BMSCs survived and differentiated into vascular endothelial cells,chondrocytes,and osteocytes.The implanted allo-BMSCs released stromal cell-derived factor 1 through paracrine signaling to recruit native BMSCs into the defect,promoting bone regeneration.This study contributes to our understanding of allo-BMSCs,providing information relevant to their future application.
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.
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.
基金supported by the National Natural Science Foundation of China(Nos.42074071,42274094,42261144739)the Shenzhen Science and Technology Program(No.KQTD20170810111725321)+2 种基金supported by the Taiwan University Core Consortiums Project(No.112L894202)the Higher Education Sprout Project of the Ministry of Education(No.112L901001)the National Science and Technology Council(No.111-2116-M-002-022-MY3)。
文摘The environmental magnetic proxies of stalagmites hold significant potential for reconstructing regional hydroclimate changes by revealing the content and grain size of magnetic particles within stalagmites.In this study,we present the contents and grain sizes of magnetic particles within a stalagmite SZ-1,from Shizhu Cave in southwestern China from 70.4 to 22.3 thousand years ago(ka)during the last glacial period.Specifically,the parameters IRM_(soft),soil-derived magnetic minerals,and ARM/SIRM(anhysteretic remanent magnetization/saturation isothermal remanent magnetization),the ratio of fine magnetic particles to total ferrimagnetic particles preserved in stalagmite SZ-1,indicate the fluctuation of regional precipitation.Obvious half-precessional cycles are evident in these two proxies,indicating that hydroclimatic variations in southwestern China may predominantly arise from the heat and moisture transported from tropical oceans.These variations are likely influenced by shifts in the Intertropical Convergence Zone and fluctuations in the Asian Summer Monsoon.
基金supported by the National Natural Science Foundation of China,Grant Nos.42477185,41602308the Zhejiang Provincial Natural Science Foundation of China,Grant No.LY20E080005+2 种基金the Zhejiang Province University Students Science and Technology Innovation Program,Grant No.0201310P28the PostGraduate Course Construction Project of Zhejiang University of Science and Technology,Grant No.2021yjskj05the Zhejiang University of Science and Technology Graduate Research and Innovation Fund,Grant No.2023yjskc10.
文摘The ongoing operation of subway systems makes existing tunnels vulnerable to deformations and structural damage caused by adjacent foundation pit construction.Such deformations-manifesting as horizontal displacement,heightened lateral convergence,and internal force redistribution-may significantly compromise subway operational safety.Grouting remediation has become a widely adopted solution for tunnel deformation control and structural reinforcement.Developing optimized grouting materials is crucial for improving remediation effectiveness,ensuring structural integrity,and maintaining uninterrupted subway operations.This investigation explores the substitution of fine mortar aggregates with 0.1 mm discarded rubber particles at varying concentrations(0%,3%,6%,9%,12%,and 15%).Experimental parameters included three water-cement ratios(0.65,0.70,and 0.75)with constant 4%WPU content.Mechanical properties including compressive strength,flexural strength,and compression-to-bending ratio were evaluated across specified curing periods.Material characterization employed Fourier Transform Infrared Spectroscopy(FTIR)spectroscopy for molecular analysis and Scanning Electron Microscopy(SEM)for microstructural examination.Results indicate optimal toughness at 0.70 water-cement ratio with 6%rubber content,meeting mechanical pumping specifications while maintaining structural performance.
基金financially supported by the Sichuan Provincial Science and Technology Fund for Distinguished Young Scholars,China(Grant No.2022JDJQ0028)Research Startup Fund by Sichuan University,China(Grant No.YJ202218).
文摘Triboelectric nanogenerators(TENGs)are emerging as new technologies to harvest electrical power from mechanical energy.With the distinctive working mechanism of triboelectric nanogenerators,they attract particular interest in healthcare monitoring,wearable electronics,and deformable energy harvesting,which raises the requirement for highly conformable devices with substantial energy outputs.Here,a simple,low-cost strategy for fabricating stretchable triboelectric nanogenerators with ultra-high electrical output is developed.The TENG is prepared using PTFE micron particles(PPTENG),contributing a different electrostatic induction process compared to TENG based on dielectric films,which was associated with the dynamics of particle motions in PP-TENG.The generator achieved an impressive voltage output of 1000 V with a current of 25 lA over a contact area of 40320 mm^(2).Additionally,the TENG exhibits excellent durability with a stretching strain of 500%,and the electrical output performance does not show any significant degradation even after 3000 cycles at a strain of 400%.The unique design of the device provides high conformability and can be used as a self-powered sensor for human motion detection.
基金financially supported by the Program of the National Natural Science Foundation of China(Grant No.52371055)the Young Elite Scientist Sponsorship Program Cast(Grant No.YESS20200139)the Basic Scientific Research Project of Liaoning Provincial Department of Education(Grant No.JYTMS20230618)。
文摘The effect of intermetallic particles on the corrosion of 6061 aluminum alloy and its coating used in semiconductor processing systems was systematically studied via liquid and gas experiments and micromorphology characterization.The results revealed that a huge difference of corrosion resistance between imported and domestic 6061 aluminum alloys in HCl solution and gas acid mist experiments mainly was attributed to the different size and amount of Al_(15)(Fe,Mn)_(3)Si_(2).The corrosion resistance of domestic 6061 alloy in dry/wet semiconductor electronic special gas environments was worse than that of imported aluminum alloy,and there are great differences in the corrosion mechanism of 6061 alloy caused by the second phase in the two dry/wet environments.And the corrosion resistance of the hard anodized alumina film was closely related to the microscopic morphology of holes.The vertical and elongatedα-Al_(15)(Mn,Fe)_(3)Si_(2) phase was formed in the rolled aluminum alloy that has been rolled perpendicular to the surface of the substrate.Compared to the horizontal long hole,the longitudinal long holes generated by the verticalα-Al_(15)(Mn,Fe)_(3)Si_(2) phase will enable the corrosive medium to reach the substrate rapidly,which significantly weakens the corrosion resistance of the hard anodized film.
基金supported by the Beijing Nova Program(No.20220484215)National Key Research and Development Program of China(Nos.2022YFB3504100,2022YFB3506200,2021YFA1500300 and 2022YFA1500146)National Natural Science Foundation of China(Nos.22376217,22208373,22272090 and 22272106)。
文摘Herein,we fabricate an embedding structure at the interface between Pt nanoparticles(NPs)and CeO_(2)-{100}nanocubes with surface defect sites(CeO_(2)-SDS)through quenching and gas bubbling-assisted membrane reduction methods.The in-situ substitution of Pt NPs for atomic-layer Ce lattice significantly increases the amount of reactive oxygen species from 133.68μmol/g to 199.44μmol/g.As a result,the distinctive geometric structure of Pt/CeO_(2)-SDS catalyst substantially improves the catalytic activity and stability for soot oxidation compared with the catalyst with no quenching process,i.e.,its T_(50)and TOF values are 332°C and 2.915 h^(-1),respectively.Combined with the results of experimental investigations and density functional theory calculations,it is unveiled that the unique embedding structure of Pt/CeO_(2)-SDS catalyst can facilitate significantly electron transfer from Pt to the CeO_(2)-{100}support,and induce the formation of interfacial[Ce-O_(x)-Pt_(2)]bond chains,which plays a crucial role in enhancing the key step of soot oxidation through the dual activation of surface lattice oxygen and molecular O_(2).Such a fundamental revelation of the interfacial electronic transmission and corresponding modification strategy contributes a novel opportunity to develop high-efficient and stable noble metal catalysts at the atomic level.
基金supported by ENN Group and ENN Energy Research Institute.
文摘This study analyzes fast ion losses in the EHL-2 fusion device,focusing on both beam ions and alpha particles as p-11B fusion reaction products.Using the Monte Carlo orbit-following code TGCO,we evaluate particle confinement under various operational scenarios,including co-injected tangential neutral beam injection at beam energies of 60 keV,80 keV,and 200 keV.Our simulations estimate the heat load driven by lost beam ions and find it to be within acceptable material limits for a plasma current on the order of mega-amperes.Additionally,we simulate the distribution of fusion products and observe a higher particle loss fraction for alpha particles compared to beam ions.However,due to the relatively low fusion power,these lost alpha particles are unlikely to significantly impact the plasma-facing materials.To assess the impact of the magnetic ripple,we compute the ripple field distribution by modelling the toroidal field(TF)coils as current filaments.The results indicate that the ripple field effect on particle confinement is minimal,primarily due to the large distance of over 1 m between the TF coils and the plasma on the low-field side.The analysis based on the test particle model is a foundational step in ensuring the basic safety aspects of the new device,which is essential for developing a robust design,optimizing performance,and maintaining safe operation.
基金supported in part by the National Key Research and Development Program of China(Grant Nos.2022YFA1604900 and 2024YFA1610700)the National Natural Science Foundation of China(Grant No.12175084)。
文摘Significant differences exist in the elliptic flowυ2 for particles and their corresponding anti-particles.These differences,which are more significant for baryons and anti-baryons,were observed from the solenoidal tracker(STAR)experiment during Beam Energy Scan I(BES-I)at relativistic heavy ion collider(RHIC).By employing the simulated many-accelerated strongly interacting hadrons(SMASH)model,we studied the ν_(2) differences between protons and anti-protons as well as between ∧ and ∧^(-)in Au+Au collisions at √S_(NN)=7.7 GeV as a function of the evolution time.It was found that as the evolution time increases,the𝑣2 differences between protons and anti-protons become more significant than those between ∧ and ∧^(-).This phenomenon can be explained by the different constituent quarks of protons and ∧.Given that some of the𝑢and𝑑quarks come from the colliding nuclei and are transported to midrapidity,they undergo more interactions than the produced quarks,resulting in protons Δν_(2) being larger than ∧Δν_(2).We compared the SMASH calculations with STAR BES-Ⅰ data and concluded that higher-precision data from BES-Ⅱ will set constraints on theoretical frameworks to interpret the ν_(2) differences between particles and anti-particles.
基金supported by the National Natural Science Foundation of China(22308348)the Natural Science Foundation of Liaoning Province of China(2024-MSBA-65)+1 种基金the Qin Chuangyuan Project for Introducing High-Level Innovative and Entrepreneurial Talents(QCYRCXM-2023-024)the Energy Revolution S&T Program of Yulin Innovation Institute of Clean Energy(E201041206).
文摘Accurately acquiring catalyst size and morphology is essential for supporting catalytic reaction process design and optimal control. We report an intelligent catalyst sizing and morphological classification method based on the Mask-RCNN framework. A dataset of 9880 high-resolution images was captured by using a self-made fiber-optic endoscopic system for 13 kinds of silicoaluminophosphate-34 (SAPO-34) catalyst samples with different coke. Then there were approximately 877881 individual particles extracted from this dataset by our AI-based particle recognition algorithm. To clearly describe the morphology of irregular particles, we proposed a hybrid classification criterion that combines five different parameters, which are deformity, circularity, roundness, aspect ratio, and compactness. Therefore, catalyst morphology can be classified into two categories with four types. The first category includes regular types, such as the spherical, ellipsoidal, and rod-shaped types. And all the irregular types fall into the second category. The experimental results showed that a catalyst particle tends to be larger when its coke deposition increased. Whereas particle morphology remained primarily spherical and ellipsoidal, the ratio of each type varied slightly according to its coke. Our findings illustrate that this is a promising approach to be developing intelligent instruments for catalyst particle sizing and classification.
文摘A type of novel biodegradable fibers,made from magnetic particles and the patient’s own blood,promises an immune-evading brain cancer therapy with minimal invasion.
文摘In the present study,we concentrate on finding the dual solutions of biomagnetic fluid namely blood flow and heat transfer along with magnetic particles over a two dimensional shrinking cylinder in the presence of a magnetic dipole.To make the results physically realistic,stability analysis is also carried out in this study so that we realized which solution is stable and which is not.The governing partial equations are converted into ordinary differential equations by using similarity transformations and the numerical solution is calculated by applying bvp4c function technique in MATLAB software.The effects of different physical parameters are plotted graphically and discussed according to the outcomes of results.From the present study we observe that ferromagnetic interaction parameter had a great influenced on fluid velocity and temperature distributions.It is also found from the current analysis that the first and second solutions of shrinking cylinder obtained only when we applied particular ranges values of suction parameter.The most important characteristics part of study is to analyze the skin friction coefficient and rate of heat transfer which also covered in this analysis.It reveals that both skin friction coefficient and rate of heat transfer are reduced with rising values of ferromagnetic number.A comparison has also been made to make the solution feasible.
基金supported by the National Natural Science Foundation of China(Nos.42307143,42307127,and 42307141)Shandong Provincial Natural Science Foundation(Nos.ZR2023QD151,ZR2024QD160,and ZR2023QD094)+2 种基金Zhejiang Province Basic Public Welfare Research Program Project(No.LGC22B050009)the Ph.D.Research Startup Foundation of Shandong University of Aeronautics(No.2022Y19)LAC/CMA(No.2023B10)。
文摘Atmospheric metal pollution is a significant environmental issue in China.Understanding the microscopic characteristics of metallic elements are crucial for investigating their sources and health effects,but this information is still limited.In this study,transmission electron microscopy(TEM)combined with bulk analysis method were employed to investigate the microscopic characteristics and mass concentrations of atmospheric metallic elements at a village site and an urban site located in North China Plain during wintertime.Our results reveal that the total mass concentrations of 16 metallic elements(including nine toxic heavy metallic elements)in PM_(2.5)were 3439.18±1101.24 ng/m^(3)(1129.6±376.85 ng/m^(3))at the village site and 3555.1±916.71 ng/m^(3)(1295.26±446.39 ng/m^(3))at urban site,accounting for 2.23%and 2.76%of PM_(2.5),respectively.We found that K,Ca,and Fe were the dominant elements,constituting over 75%of total metal mass.TEM analysis indicates that these metallic elements were mainly enriched in six types of individual particles,including K-rich,mineral,fly ash,Fe-rich,Zn-rich,and Pb-rich particles.Mineral particles were predominant in all individual metal particles at urban site,while K-rich particles became the dominant metal particles influenced by residential biomass burning at village site.Moreover,we found toxic metal particles(Fe-rich,Zn-rich,Pb-rich,and fly ash)presented smaller mean sizes(243 nm)in village air compared to urban air(337 nm),suggesting that metal particles in village air might pose a higher health risk to the residents.These results emphasize that atmospheric metal pollution in the village areas need more attentions in the future.
文摘Quantum entanglement is a bizarre, counterintuitive phenomenon which shows that entangled subatomic particles remain related even when they are far apart, which was described by Einstein as “spooky action at a distance”. Although this phenomenon could be interpreted by a few theories, for example, the famous Copenhagen interpretation which describes that these states exist simultaneously by a wave function, however, there is still no unquestioned theory and it continues to puzzle people around the world. Here we propose a hypothesis that gravity cuts out stop functioning between subatomic particles based on the observations of a thought experiment. It is well known that the Universe is filled with various subatomic particles (e.g. cosmic neutrino background, CνB) and gravity is a universal force making any particle in the Universe attract any other. Based on these observations, it is expected that the CνB particles walking abreast will be combined together by their gravity after some time/distance, which will thus result in a greatly uneven distribution of CνB. However, the observational evidence showed that CνB is highly isotropic and homogenous, suggesting that gravity would no longer work at the subatomic scale. Thus, the relation of the paired subatomic particles would become some pure correlation of mass (or equivalent energy) status. In this case, time would be not required anymore due to the ineffectiveness of gravity. The proposed new interpretation matches the experimental observations well and finally possible thought experiments are presented to test this theory.
基金supported by the Key Laboratory Fund of National Key Laboratory of Science and Technology on High-strength Structural Materials(Nos.412130024,623020031)the Pre-research Fund(No.412130024).
文摘The strength improvement in the heat-treatable Al-Zn-Mg-Cu alloys is generally achieved by increasing the volume fraction of nanoprecipitates and reducing the grain size.However,utilizing one of them usu-ally leads to a drastic decrease in ductility.Herein,we architect a hierarchical microstructure integrating bimodal grain structures,nanoprecipitates,and hard-brittle coarse particles wrapped by ductility coarse grain(CG)bands via conventional cold rolling(CR)deformation and heat treatment methods to break the strength-ductility dilemma in the Al-8.89Zn-1.98Mg-2.06Cu-0.12Zr-0.05Sc-0.05Hf(wt.%)alloy.The results reveal that the coupling of high-volume fraction(∼1.2%)nanoprecipitates,∼52%narrow CG bands,and most coarse particles encapsulated by CG bands contribute to the 45%CR sample with outstanding over-all mechanical properties(a tensile strength of 655 MPa,a yield strength of 620 MPa,and an elongation of 15.5%).Microstructure-based strength analysis confirms that the high strength relates to a trade-offbetween the hierarchical features,namely high-volume fraction nanoprecipitates to counterbalance the strength loss caused by grain coarsening.The excellent ductility is due to the introduction of medium CG content with a narrow width that can trigger a cross-scale strain distribution during plastic deforma-tion,suppressing the catastrophic failure in the fine grain(FG)regions and facilitating the dimple fracture along the CG bands.This study proposes a feasible approach for tailoring hierarchical microstructures in Al-Zn-Mg-Cu alloys to achieve a superior strength-ductility combination.
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.
