THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between c...THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between crystallographic orientation,grain boundary(GB)proximity,and pore characteristics(size/location).This study compares single-crystal nickel models along[100],[110],and[111]orientations with equiaxed polycrystalline models containing 0,1,and 2.5 nm pores in surface and subsurface configurations.Our results reveal that crystallographic anisotropy manifests as a 24.4%higher elastic modulus and 22.2%greater hardness in[111]-oriented single crystals compared to[100].Pore-GB synergistic effects are found to dominate the deformation behavior:2.5 nm subsurface pores reduce hardness by 25.2%through stress concentration and dislocation annihilation at GBs,whereas surface pores enable mechanical recovery via accelerated dislocation generation post-collapse.Additionally,size-dependent deformation regimes were identified,with 1 nm pores inducing negligible perturbation due to rapid atomic rearrangement,in contrast with persistent softening in 2.5 nm pores.These findings establish atomic-scale design principles for defect engineering in nickel-based aerospace components,demonstrating how crystallographic orientation,pore configuration,and GB interactions collectively govern nanoindentation behavior.展开更多
Photo-assisted lithium–sulfur batteries(PALSBs)offer an eco-friendly solution to address the issue of sluggish reaction kinetics of conventional LSBs.However,designing an efficient photoelectrode for practical implem...Photo-assisted lithium–sulfur batteries(PALSBs)offer an eco-friendly solution to address the issue of sluggish reaction kinetics of conventional LSBs.However,designing an efficient photoelectrode for practical implementation remains a significant challenge.Herein,we construct a free-standing polymer–inorganic hybrid photoelectrode with a direct Z-scheme heterostructure to develop high-efficiency PALSBs.Specifically,polypyrrole(PPy)is in situ vapor-phase polymerized on the surface of N-doped TiO_(2) nanorods supported on carbon cloth(N-TiO_(2)/CC),thereby forming a well-defined p–n heterojunction.This architecture efficiently facilitates the carrier separation of photo-generated electron–hole pairs and significantly enhances carrier transport by creating a built-in electric field.Thus,the PPy@N-TiO_(2)/CC can simultaneously act as a photocatalyst and an electrocatalyst to accelerate the reduction and evolution of sulfur,enabling ultrafast sulfur redox dynamics,as convincingly validated by both theoretical simulations and experimental results.Consequently,the PPy@N-TiO_(2)/CC PALSB achieves a high discharge capacity of 1653 mAh g−1,reaching 98.7%of the theoretical value.Furthermore,5 h of photo-charging without external voltage enables the PALSB to deliver a discharge capacity of 333 mAh g−1,achieving dual-mode energy harvesting capabilities.This work successfully integrates solar energy conversion and storage within a rechargeable battery system,providing a promising strategy for sustainable energy storage technologies.展开更多
Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving...Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving the overall performance of CPEs due to their difficulty in achieving robust electrochemical and mechanical interfaces simultaneously.Here,by regulating the surface charge characteristics of halloysite nanotube(HNT),we propose a concept of lithium-ion dynamic interface(Li^(+)-DI)engineering in nano-charged CPE(NCCPE).Results show that the surface charge characteristics of HNTs fundamentally change the Li^(+)-DI,and thereof the mechanical and ion-conduction behaviors of the NCCPEs.Particularly,the HNTs with positively charged surface(HNTs+)lead to a higher Li^(+)transference number(0.86)than that of HNTs-(0.73),but a lower toughness(102.13 MJ m^(-3)for HNTs+and 159.69 MJ m^(-3)for HNTs-).Meanwhile,a strong interface compatibilization effect by Li^(+)is observed for especially the HNTs+-involved Li^(+)-DI,which improves the toughness by 2000%compared with the control.Moreover,HNTs+are more effective to weaken the Li^(+)-solvation strength and facilitate the formation of Li F-rich solid-electrolyte interphase of Li metal compared to HNTs-.The resultant Li|NCCPE|LiFePO4cell delivers a capacity of 144.9 m Ah g^(-1)after 400 cycles at 0.5 C and a capacity retention of 78.6%.This study provides deep insights into understanding the roles of surface charges of nanofillers in regulating the mechanical and electrochemical interfaces in ASSLMBs.展开更多
The global energy demand is increasing rapidly,and it is imperative to develop shale hydrocarbon re-sources vigorously.The prerequisite for enhancing the exploitation efficiency of shale reservoirs is the systematic e...The global energy demand is increasing rapidly,and it is imperative to develop shale hydrocarbon re-sources vigorously.The prerequisite for enhancing the exploitation efficiency of shale reservoirs is the systematic elucidation of the occurrence characteristics,flow behavior,and enhanced oil recovery(EOR)mechanisms of shale oil within commonly developed nanopores.Molecular dynamics(MD)technique can simulate the occurrence,flow,and extraction processes of shale oil at the nanoscale,and then quantitatively characterize various fluid properties,flow characteristics,and action mechanisms under different reservoir conditions by calculating and analyzing a series of MD parameters.However,the existing review on the application of MD simulation in shale oil reservoirs is not systematic enough and lacks a summary of technical challenges and solutions.Therefore,recent MD studies on shale oil res-ervoirs were summarized and analyzed.Firstly,the applicability of force fields and ensembles of MD in shale reservoirs with different reservoir conditions and fluid properties was discussed.Subsequently,the calculation methods and application examples of MD parameters characterizing various properties of fluids at the microscale were summarized.Then,the application of MD simulation in the study of shale oil occurrence characteristics,flow behavior,and EOR mechanisms was reviewed,along with the elucidation of corresponding micro-mechanisms.Moreover,influencing factors of pore structure,wall properties,reservoir conditions,fluid components,injection/production parameters,formation water,and inorganic salt ions were analyzed,and some new conclusions were obtained.Finally,the main challenges associated with the application of MD simulations to shale oil reservoirs were discussed,and reasonable prospects for future MD research directions were proposed.The purpose of this review is to provide theoretical basis and methodological support for applying MD simulation to study shale oil reservoirs.展开更多
Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely orien...Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely oriented.Using NbOCl_(2) monolayer with competing ferroelectric(FE)and antiferroelectric(AFE)phases as a 2D material platform,we demonstrate the emergence of intrinsic antiferroelectricity in NbOCl_(2) monolayer under experimentally accessible shear strain,along with new functionality associated with electric field-induced AFE-to-FE phase transition.Specifically,the complex configuration space accommodating FE and AFE phases,polarization switching kinetics,and finite temperature thermodynamic properties of 2D NbOCl_(2) are all accurately predicted by large-scale molecular dynamics simulations based on deep learning interatomic potential model.Moreover,room temperature stable antiferroelectricity with low polarization switching barrier and one-dimensional collinear polarization arrangement is predicted in shear-deformed NbOCl_(2) monolayer.The transition from AFE to FE phase in 2D NbOCl_(2) can be triggered by a low critical electric field,leading to a double polarization–electric(P–E)loop with small hysteresis.A new type of optoelectronic device composed of AFE-NbOCl_(2) is proposed,enabling electric“writing”and nonlinear optical“reading”logical operation with fast operation speed and low power consumption.展开更多
Mitochondrial dysfunction has emerged as a critical factor in the etiology of various neurodevelopmental disorders, including autism spectrum disorders, attention-deficit/hyperactivity disorder, and Rett syndrome. Alt...Mitochondrial dysfunction has emerged as a critical factor in the etiology of various neurodevelopmental disorders, including autism spectrum disorders, attention-deficit/hyperactivity disorder, and Rett syndrome. Although these conditions differ in clinical presentation, they share fundamental pathological features that may stem from abnormal mitochondrial dynamics and impaired autophagic clearance, which contribute to redox imbalance and oxidative stress in neurons. This review aimed to elucidate the relationship between mitochondrial dynamics dysfunction and neurodevelopmental disorders. Mitochondria are highly dynamic organelles that undergo continuous fusion and fission to meet the substantial energy demands of neural cells. Dysregulation of these processes, as observed in certain neurodevelopmental disorders, causes accumulation of damaged mitochondria, exacerbating oxidative damage and impairing neuronal function. The phosphatase and tensin homolog-induced putative kinase 1/E3 ubiquitin-protein ligase pathway is crucial for mitophagy, the process of selectively removing malfunctioning mitochondria. Mutations in genes encoding mitochondrial fusion proteins have been identified in autism spectrum disorders, linking disruptions in the fusion-fission equilibrium to neurodevelopmental impairments. Additionally, animal models of Rett syndrome have shown pronounced defects in mitophagy, reinforcing the notion that mitochondrial quality control is indispensable for neuronal health. Clinical studies have highlighted the importance of mitochondrial disturbances in neurodevelopmental disorders. In autism spectrum disorders, elevated oxidative stress markers and mitochondrial DNA deletions indicate compromised mitochondrial function. Attention-deficit/hyperactivity disorder has also been associated with cognitive deficits linked to mitochondrial dysfunction and oxidative stress. Moreover, induced pluripotent stem cell models derived from patients with Rett syndrome have shown impaired mitochondrial dynamics and heightened vulnerability to oxidative injury, suggesting the role of defective mitochondrial homeostasis in these disorders. From a translational standpoint, multiple therapeutic approaches targeting mitochondrial pathways show promise. Interventions aimed at preserving normal fusion-fission cycles or enhancing mitophagy can reduce oxidative damage by limiting the accumulation of defective mitochondria. Pharmacological modulation of mitochondrial permeability and upregulation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha, an essential regulator of mitochondrial biogenesis, may also ameliorate cellular energy deficits. Identifying early biomarkers of mitochondrial impairment is crucial for precision medicine, since it can help clinicians tailor interventions to individual patient profiles and improve prognoses. Furthermore, integrating mitochondria-focused strategies with established therapies, such as antioxidants or behavioral interventions, may enhance treatment efficacy and yield better clinical outcomes. Leveraging these pathways could open avenues for regenerative strategies, given the influence of mitochondria on neuronal repair and plasticity. In conclusion, this review indicates mitochondrial homeostasis as a unifying therapeutic axis within neurodevelopmental pathophysiology. Disruptions in mitochondrial dynamics and autophagic clearance converge on oxidative stress, and researchers should prioritize validating these interventions in clinical settings to advance precision medicine and enhance outcomes for individuals affected by neurodevelopmental disorders.展开更多
Carbon nanotube formation exemplifies atomically precise self-assembly,where atomic interactions dynamically engineer nanoscale architectures with emergent properties that transcend classical material boundaries.Howev...Carbon nanotube formation exemplifies atomically precise self-assembly,where atomic interactions dynamically engineer nanoscale architectures with emergent properties that transcend classical material boundaries.However,elucidating the transient molecular intermediates remains a critical mechanistic frontier.This study investigates the atomic-scale nucleation process of single-walled carbon nanotubes(SWCNTs)from acetylene on iron(Fe)clusters,utilizing GFN(-x)TB-based nanoreactor molecular dynamics simulations.The simulations reveal a consistent nucleation pathway,regardless of iron cluster size(Fe_(13),Fe_(38),Fe_(55)),where the chemisorption and dissociation of acetylene molecules on the Fe clusters lead to the formation of C_(2)H and C_(2)intermediates.These species then undergo oligomerization,initiating the growth of carbon chains.As the chains cross-link and cyclize,five-membered carbon rings are preferentially formed,which eventually evolve into six-membered rings and more complex sp2-hybridized carbon networks,resembling the cap structures of nascent SWCNTs.Although the nucleation mechanism remains similar across all cluster sizes,larger clusters show enhanced catalytic activity,leading to higher molecular weight hydrocarbons and more extensive carbocyclic networks due to their higher density of active sites per reacting molecule.Crucially,the study highlights the role of C_(2)H as the key active species in the carbon network formation process.These findings offer critical insights into the initial stages of SWCNT nucleation,contributing to a deeper understanding of the mechanisms driving SWCNT growth and guiding the development of optimized synthetic strategies.展开更多
Background:The study examines the ecological impact of nano-micronutrient composites on the growth and maturation of late-planted wheat within an agroecological framework.Methods:Experiments conducted using a Randomiz...Background:The study examines the ecological impact of nano-micronutrient composites on the growth and maturation of late-planted wheat within an agroecological framework.Methods:Experiments conducted using a Randomized Block Design(RBD)with three replications and eight treatment combinations,ensured uniform plant populations prior to treatment applications.Significant variations were observed across multiple growth parameters,including tiller density per square meter and dry matter accumulation at 30,60,90,and 120 days after sowing(DAS).Results:Notably,the treatment involving RDF+20 ppm rGO-Fe+rGO-Zn with two foliar sprays at 45 and 60 DAS(T6)exhibited markedly superior growth performance compared to the control and conventional zinc and iron applications.Maximum grain yield(29.2 q/ha)was achieved in T8(RDF+20ppm rGO-Fe+rGO-Zn with two sprays at 45 and 60 DAS)whereas straw yield(50.5 q/ha),biological yield(77.1 q/ha),Harvest Index(38.7%)and Grain Straw ratio(0.6)were found maximum in RDF+20ppm rGO-Fe+rGO(Reduced Graphene oxide)−Zn with two sprays at 45 and 60 DAS(T6).Conclusion:The application of reduced graphene oxide(rGO)-based iron and zinc nanoparticles significantly improved nutrient uptake and utilization efficiency,leading to enhanced crop vigor and yield.The study underscores the ecological importance of integrating nanotechnology with nutrient management to sustain a healthy and balanced agroecosystem.This research focuses on sustainable agriculture,nanofertilizers,nutrient use efficiency,and ecological impact,which follows the Q16,Q57,and O13 JEL(Journal of Economic Literature)classification.展开更多
The effects of potassium(K)doping on the incipient plasticity of tungsten(W)under nanoindentation were investigated using a combination of experiments and mesoscale defects dynamic simulations.The transmission electro...The effects of potassium(K)doping on the incipient plasticity of tungsten(W)under nanoindentation were investigated using a combination of experiments and mesoscale defects dynamic simulations.The transmission electron microscopy study reveal that nanometer-sized bubbles were formed through the vaporization of K in specimens prepared by spark plasma sintering.In order to investigate the mechanical properties of the K-doped W specimens,nano-characterization experiments and defect dynamics simula-tions were conducted,comparing with those in pure W.Nanoindentation tests reveal that the maximum shear yield stress approaches the theoretical strength in annealed pure W,while K-doped W samples exhibit significant yield drop accompanied with stochastic variations.A newly developed mesoscale defect dynamics model to concurrently couple dislocation dynamics with finite element method has been also employed to investigate micro-mechanisms of plasticity under nanoindentation and the effects of K-bubbles on the plastic deformation.The simulations revealed that the localized stress concentration induced by the K-bubbles promoted dislocation nucleation and enhanced plastic deformation,thereby reducing the yield stress,showing good agreement with the experiment.展开更多
Liquid hydrogen, known for its high energy density and eco-friendly properties, has garnered significant attention in the context of sustainable development and clean energy. A comprehensive understanding of its nucle...Liquid hydrogen, known for its high energy density and eco-friendly properties, has garnered significant attention in the context of sustainable development and clean energy. A comprehensive understanding of its nucleation mechanisms and boiling heat transfer characteristics is crucial. However, current experimental and macroscopic simulation methods offer limited insights. This study employs molecular dynamics simulations to investigate the vaporization nucleation and boiling heat transfer properties of liquid hydrogen at the microscopic scale, with a focus on the effects of hydrogen film thickness, surface temperature, and wettability. The results indicate that hydrogen film thickness plays a critical role in nucleation. Thinner layers disrupt the shape of liquid films, leading to increased errors, whereas a thickness of 7 nm ensures film stability. Different heating methods and temperatures influence nucleation in various ways. Rapid heating results in a higher heat flux, while an increase in temperature under the same heating method accelerates nucleation, resulting in earlier nucleation and enhanced surface heat flow. Surfaces with varying wettability levels exhibit distinct nucleation behaviors. Specifically, an increase in α delays nucleation, causing a shift from the surface to within the liquid film due to stronger solid–liquid interaction forces. This study offers a microscale perspective on the nucleation and boiling processes of liquid hydrogen and provides valuable insights for phase transition studies.展开更多
This study investigates the effect of shock velocity(u_(p))on damage evolution mechanisms in nanocrystalline iron via molecular dynamics simulations.As u_(p)increases,shock wave propagation accelerates,and stress dist...This study investigates the effect of shock velocity(u_(p))on damage evolution mechanisms in nanocrystalline iron via molecular dynamics simulations.As u_(p)increases,shock wave propagation accelerates,and stress distribution transitions from grain boundary concentration to homogeneity.This causes a transition in fracture mode from cleavage to ductile behavior.When u_(p)exceeds 1.5 km·s^(-1),micro-spallation emerges as the dominant failure mode.During micro-spallation,localized melting within the material impedes the propagation of the shock wave.As u_(p)increases,the growth rate of the void volume fraction initially rises but then decreases.Higher u_(p)leads to earlier void nucleation.At lower u_(p),the cavitation of the model is mainly characterized by the growth and penetration of a few voids.With increasing u_(p),the number of voids grows,and their interactions expand the delamination damage region.The spall strength demonstrates stage-specific dependence on u_(p).In the classical spallation stage(C_Ⅰ),temperature softening reduces spall strength.In the plastic strengthening regime(C_Ⅱ),strain hardening enhances spall strength.In the micro-spallation stage(M_Ⅲ),further increases in u_(p)cause melting during tensile and compressive phases,reducing spall strength.Finally,in the compressionmelting regime(M_Ⅳ),local temperatures exceed the melting point,diminishing plastic damage and accelerating spall strength reduction.This study provides new insights into the dynamic response of nanocrystalline iron.展开更多
T-carbon is a new allotrope of carbon materials,and it displays high hardness and low density.Nevertheless,the hardening mechanisms of T-carbon thin films under nanoindentation remain elusive.This work utilizes molecu...T-carbon is a new allotrope of carbon materials,and it displays high hardness and low density.Nevertheless,the hardening mechanisms of T-carbon thin films under nanoindentation remain elusive.This work utilizes molecular dynamics simulation to explore the hardening mechanisms of T-carbon thin films under nanoindentation with variations of loading velocities and temperatures.The results reveal that a loading velocity increase at a given temperature raises the nanoindentation force.The increase in nanoindentation force is due to graphitization,which is related to the fracture of tetrahedral structures in T-carbon thin films.However,increased graphitization caused by an increased temperature lowers the nanoindentation force at a given loading velocity.The increased graphitization is influenced by both the fractured tetrahedrons and the deformation of inter-tetrahedron bond angles.This is attributed to the loss of thermal stability and the lower density of T-carbon thin films as the temperature increases.These findings have significant implications for the design of nanodevices for specific application requirements.展开更多
In this work,Langevin dynamics simulations were carried out to thoroughly investigate the swapping process of composite knots under tension in a cuboid nanochannel.From our analysis,the free energy profiles of knot sw...In this work,Langevin dynamics simulations were carried out to thoroughly investigate the swapping process of composite knots under tension in a cuboid nanochannel.From our analysis,the free energy profiles of knot swapping under different conditions were extracted from the overall probability distribution of the relative distance between the centers of composite knots.In addition,the impact of the stretching force,confinement size,and bending stiffness on the free energy profiles was directly identified.Especially,the influence of topology structure is for the first time reported.The increasing stretching force in a fixed confinement or the confinement size under a constant stretching force does not alter their respective equilibrium populations at the separate state and the entangled state.In contrast,a bending stiffness larger than 15 enhanced the formation of the entangled state.The topology structure of the 51knot,which was different from the 52knot,resulted in forming a metastable state in the free energy profiles.The increasing stretching forces yielded an enhancement of the following free energy barrier.展开更多
Recent advancements in nanotechnology have spotlighted the catalytic potential of nanozymes, particularly single-atom nanozymes(SANs), which are pivotal for innovations in biosensing and medical diagnostics. Among oth...Recent advancements in nanotechnology have spotlighted the catalytic potential of nanozymes, particularly single-atom nanozymes(SANs), which are pivotal for innovations in biosensing and medical diagnostics. Among others, DNA stands out as an ideal biological regulator. Its inherent programmability and interaction capabilities allow it to significantly modulate nanozyme activity. This study delves into the dynamic interplay between DNA and molybdenum-zinc single-atom nanozymes(Mo-Zn SANs). Using molecular dynamics simulations, we uncover how DNA influences the peroxidase-like activities of Mo-Zn SANs, providing a foundational understanding that broadens the application scope of SANs in biosensing.With these insights as a foundation, we developed and demonstrated a model aptasensor for point-ofcare testing(POCT), utilizing a label-free colorimetric approach that leverages DNA-nanozyme interactions to achieve high-sensitivity detection of lysozyme. Our work elucidates the nuanced control DNA exerts over nanozyme functionality and illustrates the application of this molecular mechanism through a smartphone-assisted biosensing platform. This study not only underscores the practical implications of DNA-regulated Mo-Zn SANs in enhancing biosensing platforms, but also highlights the potential of single-atom nanozyme technology to revolutionize diagnostic tools through its inherent versatility and sensitivity.展开更多
Eutectic high entropy alloys are noted for their excellent castability and comprehensive mechanical properties.The excellent mechanical properties are closely related to the activation and evolution of deformation mec...Eutectic high entropy alloys are noted for their excellent castability and comprehensive mechanical properties.The excellent mechanical properties are closely related to the activation and evolution of deformation mechanisms at the atomic scale.In this work,AlCoCrFeNi2.1 alloy is taken as the research object.The mechanical behaviors and deformation mechanisms of the FCC and B2 single crystals with different orientations and the FCC/B2 composites with K-S orientation relationship during nanoindentation processes are systematically studied by molecular dynamics simulations.The results show that the mechanical behaviors of FCC single crystals are significantly orientation-dependent,meanwhile,the indentation force of[110]single crystal is the lowest at the elastic-plastic transition point,and that for[100]single crystal is the lowest in plastic deformation stage.Compared with FCC,the stress for B2 single crystals at the elastic-plastic transition point is higher.However,more deformation systems such as stacking faults,twins and dislocation loops are activated in FCC single crystal during the plastic deformation process,resulting in higher indentation force.For composites,the flow stress increases with the increase of B2 phase thickness during the initial stage of deformation.When indenter penetrates heterogeneous interface,the significantly increased deformation system in FCC phase leads to a significant increase in indentation force.The mechanical behaviors and deformation mechanisms depend on the component single crystal.When the thickness of the component layer is less than 15 nm,the heterogeneous interfaces fail to prevent the dislocation slip and improve the indentation force.The results will enrich the plastic deformation mechanisms of multi-principal eutectic alloys and provide guidance for the design of nanocrystalline metallic materials.展开更多
Hybrid nanofluids have gained significant attention for their superior thermal and rheological characteristics,offering immense potential in energy conversion,biomedical transport,and electromagnetic flow control syst...Hybrid nanofluids have gained significant attention for their superior thermal and rheological characteristics,offering immense potential in energy conversion,biomedical transport,and electromagnetic flow control systems.Understanding their dynamic behavior under coupled magnetic,rotational,and reactive effects is crucial for the development of efficient thermal management technologies.This study develops a neuro-fuzzy computational framework to examine the dynamics of a reactive Cu–TiO_(2)–H_(2)Ohybrid nanofluid flowing through a squarely elevated Riga tunnel.The governing model incorporates Hall and ion-slip effects,thermal radiation,and first-order chemical reactions under ramped thermo-solutal boundary conditions and rotational electromagnetic forces.Closed-form analytical solutions are derived via the Laplace transform method to describe the transient velocity,temperature,and concentration fields.To complement and validate the analytical model,an artificial neural network(ANN)optimized using the Levenberg–Marquardt backpropagation algorithm(ANN-LMBPA)is trained on datasets generated in Mathematica.Regression and error analyses confirm the model’s predictive robustness,with mean squared errors ranging between 10^(-4) and 10^(-9).In addition,an Adaptive Neuro-Fuzzy Inference System(ANFIS)is developed to estimate the heat transfer rate(HTR),achieving aminimal RMSE of 0.011012 for the heat transfer coefficient(HTC).The findings reveal that rotational motion and Hall–ion slip effects suppress primary velocity but enhance secondary flow,while the modified Hartmann number(Lorentz force)accelerates both components.Thermal radiation increases fluid temperature,whereas higher Schmidt numbers and reaction rates diminish solute concentration.The HTR decreases with increasing radiation and nanoparticle volume fraction,while the mass transfer rate(MTR)improves under stronger chemical reactivity.Overall,the proposed hybrid analytical–AI framework demonstrates high accuracy and efficiency,offering valuable insights for the design and optimization of electromagnetic nanofluid systems in advanced thermal and process engineering applications.展开更多
Based on the EAM potential, a molecular dynamics study on the tensile properties of ultrathin nickel nanowires in the （100〉 orientation with diameters of 3.94, 4.95 and 5.99 nm was presented at different temperature...Based on the EAM potential, a molecular dynamics study on the tensile properties of ultrathin nickel nanowires in the （100〉 orientation with diameters of 3.94, 4.95 and 5.99 nm was presented at different temperatures and strain rates. The temperature and strain rate dependences of tensile properties were investigated. The simulation results show that the elastic modulus and the yield strength are gradually decreasing with the increase of temperature, while with the increase of the strain rate, the stress--strain curves fluctuate more intensely and the ultrathin nickel nanowires rupture at one smaller and smaller strain. At an ideal temperature of 0.01 K, the yield strength of the nanowires drops rapidly with the increase of strain rate, and at other temperatures the strain rate has a little influence on the elastic modulus and the yield strength. Finally, the effects of size on the tensile properties of ultrathin nickel nanowires were briefly discussed.展开更多
The model of ion transportation through graphene nanochannels is established by the molecular dynamics simulation method. Statistics of the electric potential and charge distribution are made, respectively, on both si...The model of ion transportation through graphene nanochannels is established by the molecular dynamics simulation method. Statistics of the electric potential and charge distribution are made, respectively, on both sides of graphene nanopore with various diameters. Then, their changing relationship with respect to the nanopore diameter is determined. When applying a uniform electric field, polar water molecules are rearranged so that the corresponding relationship between the polarized degree of these molecules and the nanopore diameter can be created. Based on the theoretical model of ion transportation through nanochannels,the changing relationship between the concentration of anions/cations in nanochannels and bulk solution concentration is quantitatively analyzed. The results show that the increase of potential drop and charge accumulation, as well as a more obvious water polarization, will occur with the decrease of nanopore diameter. In addition, hydrogen ion concentration has a large proportion in nanochannels with a sodium chloride（NaCl） solution at a relative low concentration. As the NaCl concentration increases, the concentration appreciation of sodium ions tends to be far greater than the concentration drop of chloride ions. Therefore, sodium ion concentration makes more contribution to ionic conductance.展开更多
A physical model of bulk-nanochannel-bulk with buffer baths is built up using nonequilibrium molecular dynamics （MD） simulation to study the effects of vibrating silicon atoms on the viscosity of aqueous NaCl soluti...A physical model of bulk-nanochannel-bulk with buffer baths is built up using nonequilibrium molecular dynamics （MD） simulation to study the effects of vibrating silicon atoms on the viscosity of aqueous NaCl solutions confined in the nanochannel. The simulation is performed under different moving speeds of the upper wall, different heights and different surface charge densities in the nanochannel. The simulation results indicate that with the increase in the surface charge density and the decrease in the nanochannel height and the shear rate, the vibration effect of silicon atoms on the shear viscosity of the confined fluid in the nanochannel cannot be ignored. Compared with still silicon atoms, the vibrating silicon atoms result in the decrease in the viscosity when the height of the nanochannel is less than 0.8 nm and the shear rate is less than 1.0 ×10^11 s^-1, and the effect of the vibrating silicon atoms on the shear viscosity is significant when the shear rate is small. This is due to the fact that the vibrating silicon atoms weaken the interactions between the counter-ions （Na^＋ ） and the charged surface.展开更多
The diffusion of nanoparticles immersed in semidilute polymer solutions is investigated by a hybrid mesoscopic multiparticle collision dynamics method. Effects of polymer concentration and hydrodynamic interactions am...The diffusion of nanoparticles immersed in semidilute polymer solutions is investigated by a hybrid mesoscopic multiparticle collision dynamics method. Effects of polymer concentration and hydrodynamic interactions among polymer monomers are focused. Extensive simulations show that the dependence of diffusion coefficient D on the polymer concentration c agrees with Phillies equation D-exp （-αc^δ） with a scaling exponent δ≈0.97 which coincides with the experimental one in literature. For increasing nanoparticle size, the scaling prefactor α increases monotonically while the scaling exponent always keeps fixed. Moreover, we also study the diffusion of nanoparticle without hydrodynamic interactions and find that mobility of the nanoparticle slows down, and the scaling exponent is obviously different from the one in experiments, implying that hydrodynamic interactions play a crucial role in the diffusion of a nanoparticle in semidilute polymer solutions.展开更多
基金The National Natural Science Foundation of China(Grant No.12462006)Beijing Institute of Structure and Environment Engineering Joint Innovation Fund(No.BQJJ202414).
文摘THE mechanical response and deformation mechanisms of pure nickel under nanoindentation were systematically investigated using molecular dynamics(MD)simulations,with a particular focus on the novel interplay between crystallographic orientation,grain boundary(GB)proximity,and pore characteristics(size/location).This study compares single-crystal nickel models along[100],[110],and[111]orientations with equiaxed polycrystalline models containing 0,1,and 2.5 nm pores in surface and subsurface configurations.Our results reveal that crystallographic anisotropy manifests as a 24.4%higher elastic modulus and 22.2%greater hardness in[111]-oriented single crystals compared to[100].Pore-GB synergistic effects are found to dominate the deformation behavior:2.5 nm subsurface pores reduce hardness by 25.2%through stress concentration and dislocation annihilation at GBs,whereas surface pores enable mechanical recovery via accelerated dislocation generation post-collapse.Additionally,size-dependent deformation regimes were identified,with 1 nm pores inducing negligible perturbation due to rapid atomic rearrangement,in contrast with persistent softening in 2.5 nm pores.These findings establish atomic-scale design principles for defect engineering in nickel-based aerospace components,demonstrating how crystallographic orientation,pore configuration,and GB interactions collectively govern nanoindentation behavior.
基金financial support from the National Natural Science Foundation of China(22109127)the Chinese Postdoctoral Science Foundation(2021M702666),+1 种基金he Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(Grant No.2023-TS-02)financial support from the Youth Project of"Shaanxi High-level Talents Introduction Plan"and the Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)are also sincerely appreciated.
文摘Photo-assisted lithium–sulfur batteries(PALSBs)offer an eco-friendly solution to address the issue of sluggish reaction kinetics of conventional LSBs.However,designing an efficient photoelectrode for practical implementation remains a significant challenge.Herein,we construct a free-standing polymer–inorganic hybrid photoelectrode with a direct Z-scheme heterostructure to develop high-efficiency PALSBs.Specifically,polypyrrole(PPy)is in situ vapor-phase polymerized on the surface of N-doped TiO_(2) nanorods supported on carbon cloth(N-TiO_(2)/CC),thereby forming a well-defined p–n heterojunction.This architecture efficiently facilitates the carrier separation of photo-generated electron–hole pairs and significantly enhances carrier transport by creating a built-in electric field.Thus,the PPy@N-TiO_(2)/CC can simultaneously act as a photocatalyst and an electrocatalyst to accelerate the reduction and evolution of sulfur,enabling ultrafast sulfur redox dynamics,as convincingly validated by both theoretical simulations and experimental results.Consequently,the PPy@N-TiO_(2)/CC PALSB achieves a high discharge capacity of 1653 mAh g−1,reaching 98.7%of the theoretical value.Furthermore,5 h of photo-charging without external voltage enables the PALSB to deliver a discharge capacity of 333 mAh g−1,achieving dual-mode energy harvesting capabilities.This work successfully integrates solar energy conversion and storage within a rechargeable battery system,providing a promising strategy for sustainable energy storage technologies.
基金the financial support from the National Natural Science Foundation of China(52203123 and 52473248)State Key Laboratory of Polymer Materials Engineering(sklpme2024-2-04)+1 种基金the Fundamental Research Funds for the Central Universitiessponsored by the Double First-Class Construction Funds of Sichuan University。
文摘Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving the overall performance of CPEs due to their difficulty in achieving robust electrochemical and mechanical interfaces simultaneously.Here,by regulating the surface charge characteristics of halloysite nanotube(HNT),we propose a concept of lithium-ion dynamic interface(Li^(+)-DI)engineering in nano-charged CPE(NCCPE).Results show that the surface charge characteristics of HNTs fundamentally change the Li^(+)-DI,and thereof the mechanical and ion-conduction behaviors of the NCCPEs.Particularly,the HNTs with positively charged surface(HNTs+)lead to a higher Li^(+)transference number(0.86)than that of HNTs-(0.73),but a lower toughness(102.13 MJ m^(-3)for HNTs+and 159.69 MJ m^(-3)for HNTs-).Meanwhile,a strong interface compatibilization effect by Li^(+)is observed for especially the HNTs+-involved Li^(+)-DI,which improves the toughness by 2000%compared with the control.Moreover,HNTs+are more effective to weaken the Li^(+)-solvation strength and facilitate the formation of Li F-rich solid-electrolyte interphase of Li metal compared to HNTs-.The resultant Li|NCCPE|LiFePO4cell delivers a capacity of 144.9 m Ah g^(-1)after 400 cycles at 0.5 C and a capacity retention of 78.6%.This study provides deep insights into understanding the roles of surface charges of nanofillers in regulating the mechanical and electrochemical interfaces in ASSLMBs.
基金supported by the National Natural Science Foundation of China(52304021,52104022,52204031)the Natural Science Foundation of Sichuan Province(2022NSFSC0205,2024NSFSC0201,2023NSFSC0947)the National Science and Technology Major Projects of China(2017ZX05049006-010).
文摘The global energy demand is increasing rapidly,and it is imperative to develop shale hydrocarbon re-sources vigorously.The prerequisite for enhancing the exploitation efficiency of shale reservoirs is the systematic elucidation of the occurrence characteristics,flow behavior,and enhanced oil recovery(EOR)mechanisms of shale oil within commonly developed nanopores.Molecular dynamics(MD)technique can simulate the occurrence,flow,and extraction processes of shale oil at the nanoscale,and then quantitatively characterize various fluid properties,flow characteristics,and action mechanisms under different reservoir conditions by calculating and analyzing a series of MD parameters.However,the existing review on the application of MD simulation in shale oil reservoirs is not systematic enough and lacks a summary of technical challenges and solutions.Therefore,recent MD studies on shale oil res-ervoirs were summarized and analyzed.Firstly,the applicability of force fields and ensembles of MD in shale reservoirs with different reservoir conditions and fluid properties was discussed.Subsequently,the calculation methods and application examples of MD parameters characterizing various properties of fluids at the microscale were summarized.Then,the application of MD simulation in the study of shale oil occurrence characteristics,flow behavior,and EOR mechanisms was reviewed,along with the elucidation of corresponding micro-mechanisms.Moreover,influencing factors of pore structure,wall properties,reservoir conditions,fluid components,injection/production parameters,formation water,and inorganic salt ions were analyzed,and some new conclusions were obtained.Finally,the main challenges associated with the application of MD simulations to shale oil reservoirs were discussed,and reasonable prospects for future MD research directions were proposed.The purpose of this review is to provide theoretical basis and methodological support for applying MD simulation to study shale oil reservoirs.
基金supported by the National Natural Science Foundation of China (Grant No.11574244 for G.Y.G.)the XJTU Research Fund for AI Science (Grant No.2025YXYC011 for G.Y.G.)the Hong Kong Global STEM Professorship Scheme (for X.C.Z.)。
文摘Compared to the well-studied two-dimensional(2D)ferroelectricity,the appearance of 2D antiferroelectricity is much rarer,where local dipoles from the nonequivalent sublattices within 2D monolayers are oppositely oriented.Using NbOCl_(2) monolayer with competing ferroelectric(FE)and antiferroelectric(AFE)phases as a 2D material platform,we demonstrate the emergence of intrinsic antiferroelectricity in NbOCl_(2) monolayer under experimentally accessible shear strain,along with new functionality associated with electric field-induced AFE-to-FE phase transition.Specifically,the complex configuration space accommodating FE and AFE phases,polarization switching kinetics,and finite temperature thermodynamic properties of 2D NbOCl_(2) are all accurately predicted by large-scale molecular dynamics simulations based on deep learning interatomic potential model.Moreover,room temperature stable antiferroelectricity with low polarization switching barrier and one-dimensional collinear polarization arrangement is predicted in shear-deformed NbOCl_(2) monolayer.The transition from AFE to FE phase in 2D NbOCl_(2) can be triggered by a low critical electric field,leading to a double polarization–electric(P–E)loop with small hysteresis.A new type of optoelectronic device composed of AFE-NbOCl_(2) is proposed,enabling electric“writing”and nonlinear optical“reading”logical operation with fast operation speed and low power consumption.
文摘Mitochondrial dysfunction has emerged as a critical factor in the etiology of various neurodevelopmental disorders, including autism spectrum disorders, attention-deficit/hyperactivity disorder, and Rett syndrome. Although these conditions differ in clinical presentation, they share fundamental pathological features that may stem from abnormal mitochondrial dynamics and impaired autophagic clearance, which contribute to redox imbalance and oxidative stress in neurons. This review aimed to elucidate the relationship between mitochondrial dynamics dysfunction and neurodevelopmental disorders. Mitochondria are highly dynamic organelles that undergo continuous fusion and fission to meet the substantial energy demands of neural cells. Dysregulation of these processes, as observed in certain neurodevelopmental disorders, causes accumulation of damaged mitochondria, exacerbating oxidative damage and impairing neuronal function. The phosphatase and tensin homolog-induced putative kinase 1/E3 ubiquitin-protein ligase pathway is crucial for mitophagy, the process of selectively removing malfunctioning mitochondria. Mutations in genes encoding mitochondrial fusion proteins have been identified in autism spectrum disorders, linking disruptions in the fusion-fission equilibrium to neurodevelopmental impairments. Additionally, animal models of Rett syndrome have shown pronounced defects in mitophagy, reinforcing the notion that mitochondrial quality control is indispensable for neuronal health. Clinical studies have highlighted the importance of mitochondrial disturbances in neurodevelopmental disorders. In autism spectrum disorders, elevated oxidative stress markers and mitochondrial DNA deletions indicate compromised mitochondrial function. Attention-deficit/hyperactivity disorder has also been associated with cognitive deficits linked to mitochondrial dysfunction and oxidative stress. Moreover, induced pluripotent stem cell models derived from patients with Rett syndrome have shown impaired mitochondrial dynamics and heightened vulnerability to oxidative injury, suggesting the role of defective mitochondrial homeostasis in these disorders. From a translational standpoint, multiple therapeutic approaches targeting mitochondrial pathways show promise. Interventions aimed at preserving normal fusion-fission cycles or enhancing mitophagy can reduce oxidative damage by limiting the accumulation of defective mitochondria. Pharmacological modulation of mitochondrial permeability and upregulation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha, an essential regulator of mitochondrial biogenesis, may also ameliorate cellular energy deficits. Identifying early biomarkers of mitochondrial impairment is crucial for precision medicine, since it can help clinicians tailor interventions to individual patient profiles and improve prognoses. Furthermore, integrating mitochondria-focused strategies with established therapies, such as antioxidants or behavioral interventions, may enhance treatment efficacy and yield better clinical outcomes. Leveraging these pathways could open avenues for regenerative strategies, given the influence of mitochondria on neuronal repair and plasticity. In conclusion, this review indicates mitochondrial homeostasis as a unifying therapeutic axis within neurodevelopmental pathophysiology. Disruptions in mitochondrial dynamics and autophagic clearance converge on oxidative stress, and researchers should prioritize validating these interventions in clinical settings to advance precision medicine and enhance outcomes for individuals affected by neurodevelopmental disorders.
基金supported by the National Key R&D Program of China(2022YFA1604100)the National Natural Science Foundation of China(22302220,22372187,1972157,21972160,22402218)+2 种基金the National Science Fund for Distinguished Young Scholars of China(22225206)the Fundamental Research Program of Shanxi Province(202203021222403)the Youth Innovation Promotion Association CAS(2020179)。
文摘Carbon nanotube formation exemplifies atomically precise self-assembly,where atomic interactions dynamically engineer nanoscale architectures with emergent properties that transcend classical material boundaries.However,elucidating the transient molecular intermediates remains a critical mechanistic frontier.This study investigates the atomic-scale nucleation process of single-walled carbon nanotubes(SWCNTs)from acetylene on iron(Fe)clusters,utilizing GFN(-x)TB-based nanoreactor molecular dynamics simulations.The simulations reveal a consistent nucleation pathway,regardless of iron cluster size(Fe_(13),Fe_(38),Fe_(55)),where the chemisorption and dissociation of acetylene molecules on the Fe clusters lead to the formation of C_(2)H and C_(2)intermediates.These species then undergo oligomerization,initiating the growth of carbon chains.As the chains cross-link and cyclize,five-membered carbon rings are preferentially formed,which eventually evolve into six-membered rings and more complex sp2-hybridized carbon networks,resembling the cap structures of nascent SWCNTs.Although the nucleation mechanism remains similar across all cluster sizes,larger clusters show enhanced catalytic activity,leading to higher molecular weight hydrocarbons and more extensive carbocyclic networks due to their higher density of active sites per reacting molecule.Crucially,the study highlights the role of C_(2)H as the key active species in the carbon network formation process.These findings offer critical insights into the initial stages of SWCNT nucleation,contributing to a deeper understanding of the mechanisms driving SWCNT growth and guiding the development of optimized synthetic strategies.
文摘Background:The study examines the ecological impact of nano-micronutrient composites on the growth and maturation of late-planted wheat within an agroecological framework.Methods:Experiments conducted using a Randomized Block Design(RBD)with three replications and eight treatment combinations,ensured uniform plant populations prior to treatment applications.Significant variations were observed across multiple growth parameters,including tiller density per square meter and dry matter accumulation at 30,60,90,and 120 days after sowing(DAS).Results:Notably,the treatment involving RDF+20 ppm rGO-Fe+rGO-Zn with two foliar sprays at 45 and 60 DAS(T6)exhibited markedly superior growth performance compared to the control and conventional zinc and iron applications.Maximum grain yield(29.2 q/ha)was achieved in T8(RDF+20ppm rGO-Fe+rGO-Zn with two sprays at 45 and 60 DAS)whereas straw yield(50.5 q/ha),biological yield(77.1 q/ha),Harvest Index(38.7%)and Grain Straw ratio(0.6)were found maximum in RDF+20ppm rGO-Fe+rGO(Reduced Graphene oxide)−Zn with two sprays at 45 and 60 DAS(T6).Conclusion:The application of reduced graphene oxide(rGO)-based iron and zinc nanoparticles significantly improved nutrient uptake and utilization efficiency,leading to enhanced crop vigor and yield.The study underscores the ecological importance of integrating nanotechnology with nutrient management to sustain a healthy and balanced agroecosystem.This research focuses on sustainable agriculture,nanofertilizers,nutrient use efficiency,and ecological impact,which follows the Q16,Q57,and O13 JEL(Journal of Economic Literature)classification.
基金supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(No.RS-2024-00445448)the National Research Foundation of Korea(NRF)funded by the Ministry of Science(No.NRF-2021R1A2C3005096)the ITER Technology R&D Program.
文摘The effects of potassium(K)doping on the incipient plasticity of tungsten(W)under nanoindentation were investigated using a combination of experiments and mesoscale defects dynamic simulations.The transmission electron microscopy study reveal that nanometer-sized bubbles were formed through the vaporization of K in specimens prepared by spark plasma sintering.In order to investigate the mechanical properties of the K-doped W specimens,nano-characterization experiments and defect dynamics simula-tions were conducted,comparing with those in pure W.Nanoindentation tests reveal that the maximum shear yield stress approaches the theoretical strength in annealed pure W,while K-doped W samples exhibit significant yield drop accompanied with stochastic variations.A newly developed mesoscale defect dynamics model to concurrently couple dislocation dynamics with finite element method has been also employed to investigate micro-mechanisms of plasticity under nanoindentation and the effects of K-bubbles on the plastic deformation.The simulations revealed that the localized stress concentration induced by the K-bubbles promoted dislocation nucleation and enhanced plastic deformation,thereby reducing the yield stress,showing good agreement with the experiment.
基金supported by the Youth Innovation Project of the Natural Science Foundation of Fujian Province(No.2022J05164)the Natural Science Foundation Youth Project of Xiamen Municipal Bureau of Science and Technology(No.3502Z20227047)+1 种基金the Scientific Research Foundation of Jimei University,China(No.ZQ2021053)the Fujian Provincial Department of Education,China(No.JAT210222).
文摘Liquid hydrogen, known for its high energy density and eco-friendly properties, has garnered significant attention in the context of sustainable development and clean energy. A comprehensive understanding of its nucleation mechanisms and boiling heat transfer characteristics is crucial. However, current experimental and macroscopic simulation methods offer limited insights. This study employs molecular dynamics simulations to investigate the vaporization nucleation and boiling heat transfer properties of liquid hydrogen at the microscopic scale, with a focus on the effects of hydrogen film thickness, surface temperature, and wettability. The results indicate that hydrogen film thickness plays a critical role in nucleation. Thinner layers disrupt the shape of liquid films, leading to increased errors, whereas a thickness of 7 nm ensures film stability. Different heating methods and temperatures influence nucleation in various ways. Rapid heating results in a higher heat flux, while an increase in temperature under the same heating method accelerates nucleation, resulting in earlier nucleation and enhanced surface heat flow. Surfaces with varying wettability levels exhibit distinct nucleation behaviors. Specifically, an increase in α delays nucleation, causing a shift from the surface to within the liquid film due to stronger solid–liquid interaction forces. This study offers a microscale perspective on the nucleation and boiling processes of liquid hydrogen and provides valuable insights for phase transition studies.
文摘This study investigates the effect of shock velocity(u_(p))on damage evolution mechanisms in nanocrystalline iron via molecular dynamics simulations.As u_(p)increases,shock wave propagation accelerates,and stress distribution transitions from grain boundary concentration to homogeneity.This causes a transition in fracture mode from cleavage to ductile behavior.When u_(p)exceeds 1.5 km·s^(-1),micro-spallation emerges as the dominant failure mode.During micro-spallation,localized melting within the material impedes the propagation of the shock wave.As u_(p)increases,the growth rate of the void volume fraction initially rises but then decreases.Higher u_(p)leads to earlier void nucleation.At lower u_(p),the cavitation of the model is mainly characterized by the growth and penetration of a few voids.With increasing u_(p),the number of voids grows,and their interactions expand the delamination damage region.The spall strength demonstrates stage-specific dependence on u_(p).In the classical spallation stage(C_Ⅰ),temperature softening reduces spall strength.In the plastic strengthening regime(C_Ⅱ),strain hardening enhances spall strength.In the micro-spallation stage(M_Ⅲ),further increases in u_(p)cause melting during tensile and compressive phases,reducing spall strength.Finally,in the compressionmelting regime(M_Ⅳ),local temperatures exceed the melting point,diminishing plastic damage and accelerating spall strength reduction.This study provides new insights into the dynamic response of nanocrystalline iron.
文摘T-carbon is a new allotrope of carbon materials,and it displays high hardness and low density.Nevertheless,the hardening mechanisms of T-carbon thin films under nanoindentation remain elusive.This work utilizes molecular dynamics simulation to explore the hardening mechanisms of T-carbon thin films under nanoindentation with variations of loading velocities and temperatures.The results reveal that a loading velocity increase at a given temperature raises the nanoindentation force.The increase in nanoindentation force is due to graphitization,which is related to the fracture of tetrahedral structures in T-carbon thin films.However,increased graphitization caused by an increased temperature lowers the nanoindentation force at a given loading velocity.The increased graphitization is influenced by both the fractured tetrahedrons and the deformation of inter-tetrahedron bond angles.This is attributed to the loss of thermal stability and the lower density of T-carbon thin films as the temperature increases.These findings have significant implications for the design of nanodevices for specific application requirements.
基金The National Natural Science Foundation of China under Grant Nos.11864006,11874309,12164007,and 12204118。
文摘In this work,Langevin dynamics simulations were carried out to thoroughly investigate the swapping process of composite knots under tension in a cuboid nanochannel.From our analysis,the free energy profiles of knot swapping under different conditions were extracted from the overall probability distribution of the relative distance between the centers of composite knots.In addition,the impact of the stretching force,confinement size,and bending stiffness on the free energy profiles was directly identified.Especially,the influence of topology structure is for the first time reported.The increasing stretching force in a fixed confinement or the confinement size under a constant stretching force does not alter their respective equilibrium populations at the separate state and the entangled state.In contrast,a bending stiffness larger than 15 enhanced the formation of the entangled state.The topology structure of the 51knot,which was different from the 52knot,resulted in forming a metastable state in the free energy profiles.The increasing stretching forces yielded an enhancement of the following free energy barrier.
基金supported by the Science and Technology Research Project from Education Department of Jilin Province (No. JJKH20231296KJ)the Natural Science Foundation of Science and Technology Department of Jilin Province (Joint Fund Project) (No. YDZJ202201ZYTS340)+9 种基金the Fundamental Research Funds for the Central Universities (No. 2412022ZD013)the Science and Technology Development Plan Project of Jilin Province (Nos. SKL202302030, SKL202402017, 20210204126YY, 20230204113YY, 20240602003RC, 20210402059GH)the National Natural Science Foundation of China (Nos. 22174137, 22322410, 92372102 and 22073094)the Cooperation Funding of Changchun with Chinese Academy of Sciences (No. 22SH13)the Capital Construction Fund Projects within the Budget of Jilin Province (No. 2023C042–5)the University Level Scientific Research Projects of Ordinary Universities in Xinjiang Uygur Autonomous Region (No. 2022YQSN002)the State Key Laboratory of Molecular Engineering of Polymers (Fudan University) (No. K2024–11)the Program for Young Scholars in Regional Development of CASthe essential support of the Network and Computing Center, CIAC, CASthe Computing Center of Jilin Province。
文摘Recent advancements in nanotechnology have spotlighted the catalytic potential of nanozymes, particularly single-atom nanozymes(SANs), which are pivotal for innovations in biosensing and medical diagnostics. Among others, DNA stands out as an ideal biological regulator. Its inherent programmability and interaction capabilities allow it to significantly modulate nanozyme activity. This study delves into the dynamic interplay between DNA and molybdenum-zinc single-atom nanozymes(Mo-Zn SANs). Using molecular dynamics simulations, we uncover how DNA influences the peroxidase-like activities of Mo-Zn SANs, providing a foundational understanding that broadens the application scope of SANs in biosensing.With these insights as a foundation, we developed and demonstrated a model aptasensor for point-ofcare testing(POCT), utilizing a label-free colorimetric approach that leverages DNA-nanozyme interactions to achieve high-sensitivity detection of lysozyme. Our work elucidates the nuanced control DNA exerts over nanozyme functionality and illustrates the application of this molecular mechanism through a smartphone-assisted biosensing platform. This study not only underscores the practical implications of DNA-regulated Mo-Zn SANs in enhancing biosensing platforms, but also highlights the potential of single-atom nanozyme technology to revolutionize diagnostic tools through its inherent versatility and sensitivity.
基金supported by the Natural Science Foundation of Hebei Province(E2024209052)the Youth Scholars Promotion Plan of North China University of Science and Technology(QNTJ202307).
文摘Eutectic high entropy alloys are noted for their excellent castability and comprehensive mechanical properties.The excellent mechanical properties are closely related to the activation and evolution of deformation mechanisms at the atomic scale.In this work,AlCoCrFeNi2.1 alloy is taken as the research object.The mechanical behaviors and deformation mechanisms of the FCC and B2 single crystals with different orientations and the FCC/B2 composites with K-S orientation relationship during nanoindentation processes are systematically studied by molecular dynamics simulations.The results show that the mechanical behaviors of FCC single crystals are significantly orientation-dependent,meanwhile,the indentation force of[110]single crystal is the lowest at the elastic-plastic transition point,and that for[100]single crystal is the lowest in plastic deformation stage.Compared with FCC,the stress for B2 single crystals at the elastic-plastic transition point is higher.However,more deformation systems such as stacking faults,twins and dislocation loops are activated in FCC single crystal during the plastic deformation process,resulting in higher indentation force.For composites,the flow stress increases with the increase of B2 phase thickness during the initial stage of deformation.When indenter penetrates heterogeneous interface,the significantly increased deformation system in FCC phase leads to a significant increase in indentation force.The mechanical behaviors and deformation mechanisms depend on the component single crystal.When the thickness of the component layer is less than 15 nm,the heterogeneous interfaces fail to prevent the dislocation slip and improve the indentation force.The results will enrich the plastic deformation mechanisms of multi-principal eutectic alloys and provide guidance for the design of nanocrystalline metallic materials.
文摘Hybrid nanofluids have gained significant attention for their superior thermal and rheological characteristics,offering immense potential in energy conversion,biomedical transport,and electromagnetic flow control systems.Understanding their dynamic behavior under coupled magnetic,rotational,and reactive effects is crucial for the development of efficient thermal management technologies.This study develops a neuro-fuzzy computational framework to examine the dynamics of a reactive Cu–TiO_(2)–H_(2)Ohybrid nanofluid flowing through a squarely elevated Riga tunnel.The governing model incorporates Hall and ion-slip effects,thermal radiation,and first-order chemical reactions under ramped thermo-solutal boundary conditions and rotational electromagnetic forces.Closed-form analytical solutions are derived via the Laplace transform method to describe the transient velocity,temperature,and concentration fields.To complement and validate the analytical model,an artificial neural network(ANN)optimized using the Levenberg–Marquardt backpropagation algorithm(ANN-LMBPA)is trained on datasets generated in Mathematica.Regression and error analyses confirm the model’s predictive robustness,with mean squared errors ranging between 10^(-4) and 10^(-9).In addition,an Adaptive Neuro-Fuzzy Inference System(ANFIS)is developed to estimate the heat transfer rate(HTR),achieving aminimal RMSE of 0.011012 for the heat transfer coefficient(HTC).The findings reveal that rotational motion and Hall–ion slip effects suppress primary velocity but enhance secondary flow,while the modified Hartmann number(Lorentz force)accelerates both components.Thermal radiation increases fluid temperature,whereas higher Schmidt numbers and reaction rates diminish solute concentration.The HTR decreases with increasing radiation and nanoparticle volume fraction,while the mass transfer rate(MTR)improves under stronger chemical reactivity.Overall,the proposed hybrid analytical–AI framework demonstrates high accuracy and efficiency,offering valuable insights for the design and optimization of electromagnetic nanofluid systems in advanced thermal and process engineering applications.
基金Project(51205302)supported by the National Natural Science Foundation of ChinaProject(2013JM7017)supported by the Natural Science Basic Research Plan in Shanxi Province of ChinaProject(K5051304006)supported by the Fundamental Research Funds for the Central Universities,China
文摘Based on the EAM potential, a molecular dynamics study on the tensile properties of ultrathin nickel nanowires in the （100〉 orientation with diameters of 3.94, 4.95 and 5.99 nm was presented at different temperatures and strain rates. The temperature and strain rate dependences of tensile properties were investigated. The simulation results show that the elastic modulus and the yield strength are gradually decreasing with the increase of temperature, while with the increase of the strain rate, the stress--strain curves fluctuate more intensely and the ultrathin nickel nanowires rupture at one smaller and smaller strain. At an ideal temperature of 0.01 K, the yield strength of the nanowires drops rapidly with the increase of strain rate, and at other temperatures the strain rate has a little influence on the elastic modulus and the yield strength. Finally, the effects of size on the tensile properties of ultrathin nickel nanowires were briefly discussed.
基金The National Basic Research Program of China(973Program)(No.2011CB707600)the National Natural Science Founda tion of China(No.51435003,51375092)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20160935)the Natural Science Foundation of Higher Education Institutions of Jiangsu Province(No.16KJB460015)
文摘The model of ion transportation through graphene nanochannels is established by the molecular dynamics simulation method. Statistics of the electric potential and charge distribution are made, respectively, on both sides of graphene nanopore with various diameters. Then, their changing relationship with respect to the nanopore diameter is determined. When applying a uniform electric field, polar water molecules are rearranged so that the corresponding relationship between the polarized degree of these molecules and the nanopore diameter can be created. Based on the theoretical model of ion transportation through nanochannels,the changing relationship between the concentration of anions/cations in nanochannels and bulk solution concentration is quantitatively analyzed. The results show that the increase of potential drop and charge accumulation, as well as a more obvious water polarization, will occur with the decrease of nanopore diameter. In addition, hydrogen ion concentration has a large proportion in nanochannels with a sodium chloride（NaCl） solution at a relative low concentration. As the NaCl concentration increases, the concentration appreciation of sodium ions tends to be far greater than the concentration drop of chloride ions. Therefore, sodium ion concentration makes more contribution to ionic conductance.
基金The National Basic Research Program of China ( 973Program) ( No. 2006CB300404)the National Natural Science Foundationof China ( No. 50875047, 50676019)the Natural Science Foundation ofJiangsu Province ( No. BK2006510, BK2008201)
文摘A physical model of bulk-nanochannel-bulk with buffer baths is built up using nonequilibrium molecular dynamics （MD） simulation to study the effects of vibrating silicon atoms on the viscosity of aqueous NaCl solutions confined in the nanochannel. The simulation is performed under different moving speeds of the upper wall, different heights and different surface charge densities in the nanochannel. The simulation results indicate that with the increase in the surface charge density and the decrease in the nanochannel height and the shear rate, the vibration effect of silicon atoms on the shear viscosity of the confined fluid in the nanochannel cannot be ignored. Compared with still silicon atoms, the vibrating silicon atoms result in the decrease in the viscosity when the height of the nanochannel is less than 0.8 nm and the shear rate is less than 1.0 ×10^11 s^-1, and the effect of the vibrating silicon atoms on the shear viscosity is significant when the shear rate is small. This is due to the fact that the vibrating silicon atoms weaken the interactions between the counter-ions （Na^＋ ） and the charged surface.
文摘The diffusion of nanoparticles immersed in semidilute polymer solutions is investigated by a hybrid mesoscopic multiparticle collision dynamics method. Effects of polymer concentration and hydrodynamic interactions among polymer monomers are focused. Extensive simulations show that the dependence of diffusion coefficient D on the polymer concentration c agrees with Phillies equation D-exp （-αc^δ） with a scaling exponent δ≈0.97 which coincides with the experimental one in literature. For increasing nanoparticle size, the scaling prefactor α increases monotonically while the scaling exponent always keeps fixed. Moreover, we also study the diffusion of nanoparticle without hydrodynamic interactions and find that mobility of the nanoparticle slows down, and the scaling exponent is obviously different from the one in experiments, implying that hydrodynamic interactions play a crucial role in the diffusion of a nanoparticle in semidilute polymer solutions.
