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
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
Biocompatible amphiphilic nanoparticles(NPs)with tunable particle morphology and surface property are important for their applications as functional materials.However,previously developed methods to prepare amphiphili...Biocompatible amphiphilic nanoparticles(NPs)with tunable particle morphology and surface property are important for their applications as functional materials.However,previously developed methods to prepare amphiphilic NPs generally involve several steps,especially an additional step for surface modification,greatly hindering their largescale production and widespread applications.Here,a versatile one-step strategy is developed to prepare biocompatible amphiphilic dimer NPs with tunable particle morphology and surface property.The amphiphilic dimer NPs,which consist of a hydrophobic shellac bulb and a hydrophilic poly(lactic acid)(PLA)bulb with PLA-poly(ethylene glycol)(PEG)on the bulb surface,are prepared in a single step by controlled co-precipitation and self-assembly.Amphiphilic PLA-PEG/shellac dimer NPs demonstrate excellent tunability in particle morphology,thus showing good performances in controlling the interfacial curvature and emulsion type.In addition,temperatureresponsive PLA-poly(N-isopropyl acrylamide)(PNIPAM)/shellac dimer NPs are prepared following the same method and emulsions stabilized by them show temperature-triggered response.The applications of PLA-PEG-folic acid(FA)/shellac dimer NPs for drug delivery have also been demonstrated,which show a very good performance.The strategy of preparing the dimer NPs is green,scalable,facile and versatile,which provides a good platform for the design of dimer NPs with tunable particle morphology and surface property for diverse applications.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
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
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
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
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
We review a 3d quantum gravity model, which incorporates massive spinning fields into the Euclidean path integral in a Chern-Simons formulation. Fundamental matter as defined in our previous preon model is recapped. B...We review a 3d quantum gravity model, which incorporates massive spinning fields into the Euclidean path integral in a Chern-Simons formulation. Fundamental matter as defined in our previous preon model is recapped. Both quantum gravity and the particle model are shown to be derivable from the supersymmetric 3d Chern-Simons action. Forces-Matter unification is achieved.展开更多
We present a numerical framework for simulating viscous compressible flows in the presence of solid particles with large size ratios.The volume-filtered Navier-Stokes equations are discretized using a class of high-or...We present a numerical framework for simulating viscous compressible flows in the presence of solid particles with large size ratios.The volume-filtered Navier-Stokes equations are discretized using a class of high-order low-dissipative finite difference operators with energy-preserving properties.No-slip,adiabatic boundary conditions are enforced at the surface of large particles(with diameters significantly larger than the local grid spacing)using a ghost-point immersed boundary method.Two-way coupling between the gas phase and small particles(with diameters proportional to the grid spacing)is accounted for through volumetric source terms for interphase momentum and energy exchange.A simple and efficient approach for collision detection between small and large particles is proposed.The framework is applied to simulations of planar shocks interacting with bidisperse distributions of particles with size ratios of approximately thirty.Particle dispersion and size segregation are reported and a simple analytical model for size segregation is proposed.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
The sensitivity analysis investigates the effect of particles shape(made by sphere,multi-spheres or polyhedral)for various contact force models on the calibration procedure via ring shear test.Experimental shear tests...The sensitivity analysis investigates the effect of particles shape(made by sphere,multi-spheres or polyhedral)for various contact force models on the calibration procedure via ring shear test.Experimental shear tests were performed using a Schulze Ring Shear Tester RST-01 with spherical and cubic particles.Pre-shear stress and vertical lid position behaviour were observed using Hertz-Mindlin and Linear Spring contact models.The findings confirm the necessity to include not only the shear force but also the compress behaviour of the particles in the shear test calibration.The results clearly indicate that the position of the shear lid provides discrete element method users with an important overview of the fundamental deformation behaviour and particle displacement during the pre-shear process.The results reveal differences between particle and contact force models considering the changes due to increased shear velocity useable for different representation of real-life particulate materials.The research is intended to provide DEM modellers with general information on which parameters are affected by changing the input data for each contact force model and particle shape.These insights enhance calibration procedures in both industrial and academic settings serving as a foundation for not only time optimizing DEM models and improving their accuracy.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
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
This paper presents an Eulerian-Lagrangian algorithm for direct numerical simulation(DNS)of particle-laden flows.The algorithm is applicable to perform simulations of dilute suspensions of small inertial particles in ...This paper presents an Eulerian-Lagrangian algorithm for direct numerical simulation(DNS)of particle-laden flows.The algorithm is applicable to perform simulations of dilute suspensions of small inertial particles in turbulent carrier flow.The Eulerian framework numerically resolves turbulent carrier flow using a parallelized,finite-volume DNS solver on a staggered Cartesian grid.Particles are tracked using a point-particle method utilizing a Lagrangian particle tracking(LPT)algorithm.The proposed Eulerian-Lagrangian algorithm is validated using an inertial particle-laden turbulent channel flow for different Stokes number cases.The particle concentration profiles and higher-order statistics of the carrier and dispersed phases agree well with the benchmark results.We investigated the effect of fluid velocity interpolation and numerical integration schemes of particle tracking algorithms on particle dispersion statistics.The suitability of fluid velocity interpolation schemes for predicting the particle dispersion statistics is discussed in the framework of the particle tracking algorithm coupled to the finite-volume solver.In addition,we present parallelization strategies implemented in the algorithm and evaluate their parallel performance.展开更多
This study investigates the properties of high-purity starches extracted from Polygonum multiflorum(PMS)and Smilax glabra(SGS).The starches were characterized by scanning electron microscopy,Fouriertransform infrared ...This study investigates the properties of high-purity starches extracted from Polygonum multiflorum(PMS)and Smilax glabra(SGS).The starches were characterized by scanning electron microscopy,Fouriertransform infrared spectroscopy,X-ray diffraction,high-performance anion-exchange chromatography,and differential scanning calorimetry.Significant differences were observed in their morphological,physicochemical,and functional properties.PMS had a smaller particle size(13.68 μm),irregular polygonal shape,A-type,lower water absorption(62.67 %),and higher oil absorption(51.17 %).In contrast,SGS exhibited larger particles(31.75 μm),a nearly spherical shape,B-type,higher crystallinity(50.66 %),and greater amylose content(21.54 %),with superior thermal stability,shear resistance,and gelatinization enthalpy.SGS also contained higher resistant starch(83.28 %) and longer average chain length(20.58 %),but showed lower solubility,swelling power,light transmittance,and freeze-thaw stability.The physicochemical properties differences in crystal pattern and particle morphology between PMS and SGS lead to distinct behaviors during in vitro digestion and fermentation.These findings highlight the potential of medicinal plant starches in functional ingredients and industrial processes.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
The Feynman ratchet has the ability to convert random fluctuations into directional particle transport.The transport velocity of particles is highly dependent on their size,leading to directional transport and subsequ...The Feynman ratchet has the ability to convert random fluctuations into directional particle transport.The transport velocity of particles is highly dependent on their size,leading to directional transport and subsequent particle separation under suitable parameter conditions.Here,exploiting the distinct responses of particles with different sizes to the system,the separation of bi-dispersed dust particles is achieved experimentally in air at 35 Pa using a dusty plasma ratchet.To reveal the underlying mechanisms,we construct a plasma model and perform Langevin simulations for the particle separation.Our numerical results reveal that charged dust particles experience an asymmetric ratchet potential,which dictates their directional transport.Crucially,bi-dispersed dust particles are suspended at different heights and are subject to ratchet potentials with opposing asymmetries,resulting in their separation.These findings may offer new perspectives for related fields,including microfluidics,nanotechnology,and micrometer-scale particle manipulation.展开更多
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(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 National Natural Science Foundation of China(No.22278352)National Key Research and Development Program of China(No.2021YFC3001100)+3 种基金Longyan City Science and Technology Plan Project(No.2020LYF17043)Longyan City Science and Technology Plan Project(No.2020LYF17042)ARC Discovery Project(No.DP200101238)and NHMRC Investigator Grant(No.APP2008698)supported by the Harvard Materials Research Science and Engineering Center(No.DMR2011754)。
文摘Biocompatible amphiphilic nanoparticles(NPs)with tunable particle morphology and surface property are important for their applications as functional materials.However,previously developed methods to prepare amphiphilic NPs generally involve several steps,especially an additional step for surface modification,greatly hindering their largescale production and widespread applications.Here,a versatile one-step strategy is developed to prepare biocompatible amphiphilic dimer NPs with tunable particle morphology and surface property.The amphiphilic dimer NPs,which consist of a hydrophobic shellac bulb and a hydrophilic poly(lactic acid)(PLA)bulb with PLA-poly(ethylene glycol)(PEG)on the bulb surface,are prepared in a single step by controlled co-precipitation and self-assembly.Amphiphilic PLA-PEG/shellac dimer NPs demonstrate excellent tunability in particle morphology,thus showing good performances in controlling the interfacial curvature and emulsion type.In addition,temperatureresponsive PLA-poly(N-isopropyl acrylamide)(PNIPAM)/shellac dimer NPs are prepared following the same method and emulsions stabilized by them show temperature-triggered response.The applications of PLA-PEG-folic acid(FA)/shellac dimer NPs for drug delivery have also been demonstrated,which show a very good performance.The strategy of preparing the dimer NPs is green,scalable,facile and versatile,which provides a good platform for the design of dimer NPs with tunable particle morphology and surface property for diverse applications.
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 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.
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.
文摘We review a 3d quantum gravity model, which incorporates massive spinning fields into the Euclidean path integral in a Chern-Simons formulation. Fundamental matter as defined in our previous preon model is recapped. Both quantum gravity and the particle model are shown to be derivable from the supersymmetric 3d Chern-Simons action. Forces-Matter unification is achieved.
基金This work used Expanse systems at UCSD through an allocation[PHY240089]from the Advanced Cyberinfrastructure Coordination Ecosystem:Services&Support(ACCESS)programsupported by U.S.National Science Foundation(Grant Nos.2138259,2138286,2138307,2137603 and 2138296).
文摘We present a numerical framework for simulating viscous compressible flows in the presence of solid particles with large size ratios.The volume-filtered Navier-Stokes equations are discretized using a class of high-order low-dissipative finite difference operators with energy-preserving properties.No-slip,adiabatic boundary conditions are enforced at the surface of large particles(with diameters significantly larger than the local grid spacing)using a ghost-point immersed boundary method.Two-way coupling between the gas phase and small particles(with diameters proportional to the grid spacing)is accounted for through volumetric source terms for interphase momentum and energy exchange.A simple and efficient approach for collision detection between small and large particles is proposed.The framework is applied to simulations of planar shocks interacting with bidisperse distributions of particles with size ratios of approximately thirty.Particle dispersion and size segregation are reported and a simple analytical model for size segregation is proposed.
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This paper was created as part of the project No.CZ.02.01.01/00/22_008/0004631 Materials and technologies for sustainable development within the Jan Amos Komensky Operational Program financed by the European Union and from the state budget of the Czech Republic,and project The European Just Transition Fund supported this work within the Operational Programme Just Transition under the aegis of the Ministry of the Environment of the Czech Republic,project CirkArena,number CZ.10.03.01/00/22_003/0000045supported by Grant of SGS No.SP2025/005 Development of measuring apparatus for determination of thermodynamic properties of mineral raw materials for design of process and treatment plants,Faculty of Mining and Geology,VSB-Technical University Ostrava,Czech Republic.
文摘The sensitivity analysis investigates the effect of particles shape(made by sphere,multi-spheres or polyhedral)for various contact force models on the calibration procedure via ring shear test.Experimental shear tests were performed using a Schulze Ring Shear Tester RST-01 with spherical and cubic particles.Pre-shear stress and vertical lid position behaviour were observed using Hertz-Mindlin and Linear Spring contact models.The findings confirm the necessity to include not only the shear force but also the compress behaviour of the particles in the shear test calibration.The results clearly indicate that the position of the shear lid provides discrete element method users with an important overview of the fundamental deformation behaviour and particle displacement during the pre-shear process.The results reveal differences between particle and contact force models considering the changes due to increased shear velocity useable for different representation of real-life particulate materials.The research is intended to provide DEM modellers with general information on which parameters are affected by changing the input data for each contact force model and particle shape.These insights enhance calibration procedures in both industrial and academic settings serving as a foundation for not only time optimizing DEM models and improving their accuracy.
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 P.G.Senapathy Center for Computing Resources at IIT Madrasfunding provided by the Ministry of Education,Government of Indiasupported by the National Natural Science Foundation of China(Grant Nos.12388101,12472224 and 92252104).
文摘This paper presents an Eulerian-Lagrangian algorithm for direct numerical simulation(DNS)of particle-laden flows.The algorithm is applicable to perform simulations of dilute suspensions of small inertial particles in turbulent carrier flow.The Eulerian framework numerically resolves turbulent carrier flow using a parallelized,finite-volume DNS solver on a staggered Cartesian grid.Particles are tracked using a point-particle method utilizing a Lagrangian particle tracking(LPT)algorithm.The proposed Eulerian-Lagrangian algorithm is validated using an inertial particle-laden turbulent channel flow for different Stokes number cases.The particle concentration profiles and higher-order statistics of the carrier and dispersed phases agree well with the benchmark results.We investigated the effect of fluid velocity interpolation and numerical integration schemes of particle tracking algorithms on particle dispersion statistics.The suitability of fluid velocity interpolation schemes for predicting the particle dispersion statistics is discussed in the framework of the particle tracking algorithm coupled to the finite-volume solver.In addition,we present parallelization strategies implemented in the algorithm and evaluate their parallel performance.
基金supported by the National Natural Science Foundation of China (No.82174074)。
文摘This study investigates the properties of high-purity starches extracted from Polygonum multiflorum(PMS)and Smilax glabra(SGS).The starches were characterized by scanning electron microscopy,Fouriertransform infrared spectroscopy,X-ray diffraction,high-performance anion-exchange chromatography,and differential scanning calorimetry.Significant differences were observed in their morphological,physicochemical,and functional properties.PMS had a smaller particle size(13.68 μm),irregular polygonal shape,A-type,lower water absorption(62.67 %),and higher oil absorption(51.17 %).In contrast,SGS exhibited larger particles(31.75 μm),a nearly spherical shape,B-type,higher crystallinity(50.66 %),and greater amylose content(21.54 %),with superior thermal stability,shear resistance,and gelatinization enthalpy.SGS also contained higher resistant starch(83.28 %) and longer average chain length(20.58 %),but showed lower solubility,swelling power,light transmittance,and freeze-thaw stability.The physicochemical properties differences in crystal pattern and particle morphology between PMS and SGS lead to distinct behaviors during in vitro digestion and fermentation.These findings highlight the potential of medicinal plant starches in functional ingredients and industrial processes.
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 National Natural Science Foundation of China(Nos.12275064 and 12475203)the Hebei Natural Science Fund(No.A2024201020)+1 种基金Hebei University Natural Science Research Innovation Team Project(No.IT2023B03)the Post-graduate’s Innovation Fund Project of Hebei University(No.HBU2024BS007)。
文摘The Feynman ratchet has the ability to convert random fluctuations into directional particle transport.The transport velocity of particles is highly dependent on their size,leading to directional transport and subsequent particle separation under suitable parameter conditions.Here,exploiting the distinct responses of particles with different sizes to the system,the separation of bi-dispersed dust particles is achieved experimentally in air at 35 Pa using a dusty plasma ratchet.To reveal the underlying mechanisms,we construct a plasma model and perform Langevin simulations for the particle separation.Our numerical results reveal that charged dust particles experience an asymmetric ratchet potential,which dictates their directional transport.Crucially,bi-dispersed dust particles are suspended at different heights and are subject to ratchet potentials with opposing asymmetries,resulting in their separation.These findings may offer new perspectives for related fields,including microfluidics,nanotechnology,and micrometer-scale particle manipulation.
