Establishing a base on the Moon is one of the new goals of human lunar exploration in recent years.Sintered lunar regolith is one of the most potential building materials for lunar bases.The physical,mechanical and th...Establishing a base on the Moon is one of the new goals of human lunar exploration in recent years.Sintered lunar regolith is one of the most potential building materials for lunar bases.The physical,mechanical and thermal properties of sintered lunar regolith are vital performance indices for the structural design of a lunar base and analysis of many critical mechanical and thermal issues.In this study,the HUST-1 lunar regolith simulant(HLRS)was sintered at 1030,1040,1050,1060,1070,and 1080℃.The effect of sintering temperature on the compressive strength was investigated,and the exact value of the optimum vacuum sintering temperature was determined between 1040 and 1060℃.Then,the microstructure and material composition of vacuum sintered HLRS at different temperatures were characterized.It was found that the sintering temperature has no significant effect on the mineral composition in the temperature range of 1030-1080℃.Besides,the heat capacity,thermal conductivity,and coefficient of thermal expansion(CTE)of vacuum sintered HLRS at different temperatures were investigated.Specific heat capacity of sintered samples increases with the increase of test temperature within the temperature range from-75 to 145℃.Besides,the thermal conductivity of the sintered sample is proportional to density.Finally,the two temperatures of 1040 and 1050℃were selected for a more detailed study of mechanical properties.The results showed that compressive strength of sintered sample is much higher than tensile strength.This study reveals the effects of sintering temperature on the physical,mechanical and thermal properties of vacuum sintered HLRS,and these material parameters will provide support for the construction of future lunar bases.展开更多
Leading national space exploration agencies and private enterprises are actively engaged in lunar exploration initiatives to accomplish manned lunar landings and establish permanent lunar bases in the forthcoming year...Leading national space exploration agencies and private enterprises are actively engaged in lunar exploration initiatives to accomplish manned lunar landings and establish permanent lunar bases in the forthcoming years.With limited access to lunar surface materials on Earth,lunar regolith simulants are crucial for lunar exploration research.The Chang’e-5(CE-5)samples have been characterized by state-of-the-art laboratory equipment,providing a unique opportunity to develop a high-quality lunar regolith simulant.We have prepared a high-fidelity PolyU-1 simulant by pulverizing,desiccating,sieving,and blending natural mineral materials on Earth based on key physical,mineral,and chemical characteristics of CE-5 samples.The results showed that the simulant has a high degree of consistency with the CE-5 samples in terms of the particle morphology,mineral and chemical composition.Direct shear tests were conducted on the simulant,and the measured internal friction angle and cohesion values can serve as references for determining the mechanical properties of CE-5 lunar regolith.The PolyU-1 simulant can contribute to experimental studies involving lunar regolith,including the assessment of interaction between rovers and lunar regolith,as well as the development of in-situ resource utilization(ISRU)technologies.展开更多
Lunar in-situ resource utilization(ISRU)has been put on the agenda by many countries.Due to the special material nature and low gravity environment,the lunar regolith demonstrates significantly different behavior from...Lunar in-situ resource utilization(ISRU)has been put on the agenda by many countries.Due to the special material nature and low gravity environment,the lunar regolith demonstrates significantly different behavior from terrestrial geomaterials.However,the systematic understanding of its geotechnical behavior is now seriously restricted by the scarcity of lunar regolith and the difficulty in simulating lunar gravity.A new lunar regolith simulant,termed as China University of Mining and Technology Number One(CUMT-1),has been developed to recover properties of the lunar regolith and simulate the lunar gravity by adopting the recently advanced geotechnical magnetic-similitude-gravity model testing(GMMT)method.The CUMT-1 simulant was prepared by reproducing the in-situ formation and fragmentation of the lunar matrix,which plays a key role in the irregular particle morphology.The mineralogical compositions,particle morphology and gradation,specific gravity,bulk density,void ratio,shear strength,and compressibility were determined.After quantifying the magnetization and magnetic-similitude-gravity characteristics,an application of the cone penetration resistance under low gravity was further given.The obtained results are compared to the values known for lunar regolith samples and other simulants,which demonstrates promising characteristics for use in geotechnical engineering-based and scientificbased applications,especially considering the influence of lunar gravity.展开更多
With the increasing scarcity of Earth’s resources and the development of space science and technology,the exploration, development, and utilization of deep space-specific material resources(minerals, water ice, volat...With the increasing scarcity of Earth’s resources and the development of space science and technology,the exploration, development, and utilization of deep space-specific material resources(minerals, water ice, volatile compounds, etc.) are not only important to supplement the resources and reserves on Earth but also provide a material foundation for establishing extraterrestrial research bases. To achieve large depth in-situ condition-preserved coring(ICP-Coring) in the extreme lunar environment, first, lunar rock simulant was selected(SZU-1), which has a material composition, element distribution, and physical and mechanical properties that are approximately equivalent to those of lunar mare basalt. Second, the influence of the lunar-based in-situ environment on the phase, microstructure, and thermal physical properties(specific heat capacity, thermal conductivity, thermal diffusivity, and thermal expansion coefficient)of SZU-1 was explored and compared with the measured lunar rock data. It was found that in an air atmosphere, low temperature has a more pronounced effect on the relative content of olivine than other temperatures, while in a vacuum atmosphere, the relative contents of olivine and anorthite are significantly affected only at temperatures of approximately-20 and 200 ℃. When the vacuum level is less than100 Pa, the contribution of air conduction can be almost neglected, whereas it becomes dominant above this threshold. Additionally, as the testing temperature increases, the surface of SZU-1 exhibits increased microcracking, fracture opening, and unevenness, while the specific heat capacity, thermal conductivity,and thermal expansion coefficient show nonlinear increases. Conversely, the thermal diffusivity exhibits a nonlinear decreasing trend. The relationship between thermal conductivity, thermal diffusivity, and temperature can be effectively described by an exponential function(R^(2)>0.98). The research results are consistent with previous studies on real lunar rocks. These research findings are expected to be applied in the development of the test and analysis systems of ICP-Coring in a lunar environment and the exploration of the mechanism of machine-rock interaction in the in-situ drilling and coring process.展开更多
Low-temperature plasma is a green and high-efficiency technology for chemical warfare agent(CWA)decontamination.However,traditional plasma devices suffer from the problems of highpower composition and large power-supp...Low-temperature plasma is a green and high-efficiency technology for chemical warfare agent(CWA)decontamination.However,traditional plasma devices suffer from the problems of highpower composition and large power-supply size,which limit their practical applications.In this paper,a self-driven microplasma decontamination system,induced by a dielectric-dielectric rotary triboelectric nanogenerator(dd-r TENG),was innovatively proposed for the decontamination of CWA simulants.The microplasma was characterized via electrical measurements,optical emission spectra and ozone concentration detection.With an output voltage of-3460 V,the dd-r TENG can successfully excite microplasma in air.Reactive species,such as OH,O(1D),Hαand O3were detected.With input average power of 0.116 W,the decontamination rate of 2-chloroethyl ethyl sulfide reached 100%within 3 min of plasma treatment,while the decontamination rates of malathion and dimethyl methylphosphonate reached(65.92±1.65)%and(60.88±1.92)%after 7 min of plasma treatment,respectively.In addition,the decontamination rates gradually decreased with the increase in the simulant concentrations.Typical products were identified and analyzed.This study demonstrates the broad spectrum and feasibility of the dd-r TENG-microplasma for CWA elimination,which provides significant guidance for their practical applications in the future.展开更多
The response of biological phantoms against high velocity impact is actively sought for applications in defense,space,soft robotics and sensing.Towards this end,we study the ballistic response of silicone based skin s...The response of biological phantoms against high velocity impact is actively sought for applications in defense,space,soft robotics and sensing.Towards this end,we study the ballistic response of silicone based skin simulant against fragment impact.Using a pneumatic gas gun setup,six chisel-nosed and three regular shaped(sphere,cylinder,and cube)fragments were impacted on the skin simulant.The resulting skin simulant response was studied in terms of ballistic limit velocities,energy densities,failure pattern,and the mechanics of interaction.The results indicate that the shape of the fragment affects the ballistic limit velocities.The ballistic limit velocities,energy densities of the chisel-nosed fragment simulating projectiles were relatively insensitive to the size(mass),except for the smallest(0.16 g)and largest(2.79 g)chisel-nosed fragment.For the same size(1 g),ballistic limit velocities and failure are dependent on the shape of the fragment.The skin simulant failed by combined plugging and elastic hole enlargement.Failure in the spherical fragment was dominated by the elastic hole enlargement,whereas plugging failure was dominant in all other fragments.The spherical,cylindrical,and chisel-nosed fragments created circular cavities,and the cubical fragment created a square cavity.In the case of the spherical fragment,slipping of the fragment within the skin simulant was seen.Cubical fragments created lateral cracks emanating from the corners of the square cavity.Interestingly,for all the fragments,the maximum deformation corresponding to the perforation was lower than the non-perforation indicating rate dependent,stress driven failure.The maximum deformation was also dependent on the shape of the fragment.Overall,these results provide unique insights into the mechanical response of a soft simulant against ballistic impact.Results have utility in the calibration and validation of computational models,design of personal protective equipment,and antipersonnel systems.展开更多
Punch loading is a loading scenario to study the fracture mechanism of materials at low strain rates.In this paper,three punch loading experimental patterns were chosen for the study of compressional punch loading.A p...Punch loading is a loading scenario to study the fracture mechanism of materials at low strain rates.In this paper,three punch loading experimental patterns were chosen for the study of compressional punch loading.A polymer bonded explosive（PBX） simulant was experimentally studied using the digital image correlation（DIC） method.The displacement and strain fields were obtained and the fracture behavior and failure mechanisms of samples were investigated under different punch loading conditions.Moreover,scanning electron microscope（SEM） was used to examine the region of the plastic flow and the damage in the material.The formation of slip bands,shear displacement and fracture of the hard phase particle,were observed on the boundary of the dead zone due to the large shear strains.展开更多
The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this wo...The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.展开更多
Thermally activated delayed fluorescence(TADF)molecules have outstanding potential for applications in organic light-emitting diodes(OLEDs).Due to the lack of systematic studies on the correlation between molecular st...Thermally activated delayed fluorescence(TADF)molecules have outstanding potential for applications in organic light-emitting diodes(OLEDs).Due to the lack of systematic studies on the correlation between molecular structure and luminescence properties,TADF molecules are far from meeting the needs of practical applications in terms of variety and number.In this paper,three twisted TADF molecules are studied and their photophysical properties are theoretically predicted based on the thermal vibrational correlation function method combined with multiscale calculations.The results show that all the molecules exhibit fast reverse intersystem crossing(RISC)rates(kRISC),predicting their TADF luminescence properties.In addition,the binding of DHPAzSi as the donor unit with different acceptors can change the dihedral angle between the ground and excited states,and the planarity of the acceptors is positively correlated with the reorganization energy,a property that has a strong influence on the non-radiative process.Furthermore,a decrease in the energy of the molecular charge transfer state and an increase in the kRISC were observed in the films.This study not only provides a reliable explanation for the observed experimental results,but also offers valuable insights that can guide the design of future TADF molecules.展开更多
Explorations into new electrolytes have highlighted the critical impact of solvation structure on battery performance,Classical molecular dynamics(CMD)using semi-empirical force fields has become an essential tool for...Explorations into new electrolytes have highlighted the critical impact of solvation structure on battery performance,Classical molecular dynamics(CMD)using semi-empirical force fields has become an essential tool for simulating solvation structures.However,mainstream force fields often lack accuracy in describing strong ion-solvent interactions,causing disparities between CMD simulations and experimental observations.Although some empirical methods have been employed in some of the studies to address this issue,their effectiveness has been limited.Our CMD research,supported by quantum chemical calculations and experimental data,reveals that the solvation structure is influenced not only by the charge model but also by the polarization description.Previous empirical approaches that focused solely on adjusting ion-solvent interaction strengths overlooked the importance of polarization effects.Building on this insight,we propose integrating the Drude polarization model into mainstream force fields and verify its feasibility in carbonate,ether,and nitrile electrolytes.Our experimental results demonstrate that this approach significantly enhances the accuracy of CMD-simulated solvation structures.This work is expected to provide a more reliable CMD method for electrolyte design,shielding researchers from the pitfalls of erroneous simulation outcomes.展开更多
Understanding the reinforcement effect of the newly developed prestressed reinforcement components(PRCs)(a system composed of prestressed steel bars(PSBs),protective sleeves,lateral pressure plates(LPPs),and anchoring...Understanding the reinforcement effect of the newly developed prestressed reinforcement components(PRCs)(a system composed of prestressed steel bars(PSBs),protective sleeves,lateral pressure plates(LPPs),and anchoring elements)is technically significant for the rational design of prestressed subgrade.A three-dimensional finite element model was established and verified based on a novel static model test and utilized to systematically analyze the influence of prestress levels and reinforcement modes on the reinforcement effect of the subgrade.The results show that the PRCs provide additional confining pressure to the subgrade through the diffusion effect of the prestress,which can therefore effectively improve the service performance of the subgrade.Compared to the unreinforced conventional subgrades,the settlements of prestressreinforced subgrades are reduced.The settlement attenuation rate(Rs)near the LPPs is larger than that at the subgrade center,and increasing the prestress positively contributes to the stability of the subgrade structure.In the multi-row reinforcement mode,the reinforcement effect of PRCs can extend from the reinforced area to the unreinforced area.In addition,as the horizontal distance from the LPPs increases,the additional confining pressure converted by the PSBs and LPPs gradually diminishes when spreading to the core load bearing area of the subgrade,resulting in a decrease in the Rs.Under the singlerow reinforcement mode,PRCs can be strategically arranged according to the local areas where subgrade defects readily occurred or observed,to obtain the desired reinforcement effect.Moreover,excessive prestress should not be applied near the subgrade shoulder line to avoid the shear failure of the subgrade shoulder.PRCs can be flexibly used for preventing and treating various subgrade defects of newly constructed or existing railway lines,achieving targeted and classified prevention,and effectively improving the bearing performance and deformation resistance of the subgrade.The research results are instructive for further elucidating the prestress reinforcement effect of PRCs on railway subgrades.展开更多
In order to support the physical research on the EAST tokamak,a new positive ion source with designed beam energy of 120 keV was proposed to be developed.Accelerator structure is one of the key components of the ion s...In order to support the physical research on the EAST tokamak,a new positive ion source with designed beam energy of 120 keV was proposed to be developed.Accelerator structure is one of the key components of the ion source.Through the finite element analysis method,the electrostatic analyses of insulators and grid plates were carried out,the material and structure parameters of insulators were determined.The maximum electric field around each insulator is about 4 kV/mm,and the maximum electric field between grids is about 14 kV/mm,which can meet the 120 keV withstand voltage holding.The insulation system for the positive ion source accelerator with 120 keV is designed,and the connection and basic parameters of insulators and support flanges are analyzed and determined.展开更多
Based on the principles of thermodynamics, we elucidate the fundamental reasons behind the hysteresis of spontaneous polarization in ferroelectric materials during heating and cooling processes. By utilizing the effec...Based on the principles of thermodynamics, we elucidate the fundamental reasons behind the hysteresis of spontaneous polarization in ferroelectric materials during heating and cooling processes. By utilizing the effective Hamiltonian method in conjuction with the phase-field model, we have successfully reproduced the thermal hysteresis observed in ferroelectric materials during phase transitions. The computational results regarding the electrocaloric effect from these two different computational scales closely align with experimental measurements. Furthermore, we analyze how the first-order ferroelectric phase transition gradually diminishes with an increasing applied electric field, exhibiting characteristics of second-order-like phase transition. By employing the characteristic parameters of thermal hysteresis, we have established a pathway for calculations across different computational scales, thereby providing theoretical support for further investigations into the properties of ferroelectric materials through concurrent multiscale simulations.展开更多
Accurate acquisition of the rock stress is crucial for various rock engineering applications.The hollow inclusion (HI) technique is widely used for measuring in-situ rock stress.This technique calculates the stress te...Accurate acquisition of the rock stress is crucial for various rock engineering applications.The hollow inclusion (HI) technique is widely used for measuring in-situ rock stress.This technique calculates the stress tensor by measuring strain using an HI strain cell.However,existing analytical solutions for stress calculation based on an HI strain cell in a double-layer medium are not applicable when an HI strain cell is used in a three-layer medium,leading to erroneous stress calculations.To address this issue,this paper presents a method for calculating stress tensors in a three-layer medium using numerical simulations,specifically by obtaining a constitutive matrix that relates strain measurements to stress tensors in a three-layer medium.Furthermore,using Latin hypercube sampling (LHS) and orthogonal experimental design strategies,764 groups of numerical models encompassing various stress measurement scenarios have been established and calculated using FLAC^(3D)software.Finally,a surrogate model based on artificial neural network (ANN) was developed to predict constitutive matrices,achieving a goodness of fit (R^(2)) of 0.999 and a mean squared error (MSE) of 1.254.A software program has been developed from this surrogate model for ease of use in practical engineering applications.The method’s accuracy was verified through numerical simulations,analytical solution and laboratory experiment,demonstrating its effectiveness in calculating stress in a three-layer medium.The surrogate model was applied to calculate mining-induced stress in the roadway roof rock of a coal mine,a typical case for stress measurement in a three-layer medium.Errors in stress calculations arising from the use of existing analytical solutions were corrected.The study also highlights the significant errors associated with using double-layer analytical solutions in a three-layer medium,which could lead to inappropriate engineering design.展开更多
Uranium–molybdenum(U–Mo) alloys are critical for nuclear power generation and propulsion because of their superior thermal conductivity, irradiation stability, and anti-swelling properties. This study explores the p...Uranium–molybdenum(U–Mo) alloys are critical for nuclear power generation and propulsion because of their superior thermal conductivity, irradiation stability, and anti-swelling properties. This study explores the plastic deformation mechanisms of γ-phase U–Mo alloys using molecular dynamics(MD) simulations. In the slip model, the generalized stacking fault energy(GSFE) and the modified Peierls–Nabarro(P–N) model are used to determine the competitive relationships among different slip systems. In the twinning model, the generalized plane fault energy(GPFE) is assessed to evaluate the competition between slip and twinning. The findings reveal that among the three slip systems, the {110}<111>slip system is preferentially activated, while in the {112}<111> system, twinning is favored over slip, as confirmed by MD tensile simulations conducted in various directions. Additionally, the impact of Mo content on deformation behavior is emphasized. Insights are provided for optimizing process conditions to avoid γ → α′′ transitions, thereby maintaining a higher proportion of γ-phase U–Mo alloys for practical applications.展开更多
Two asymmetric types of floating breakwaters integrated with a wave energy converter(WEC-FBs),a floating square box with a triangle(trapezoidal type)or a wave baffle(L type)attached to its rear side,have been proposed...Two asymmetric types of floating breakwaters integrated with a wave energy converter(WEC-FBs),a floating square box with a triangle(trapezoidal type)or a wave baffle(L type)attached to its rear side,have been proposed.In this research,the hydrodynamic performance,including capture width ratio(CWR),wave transmission coefficient,heave motion,and force coefficient,were studied and compared between the two types.A numerical simulation model based on the Navier-Stokes equation was employed.The effects of power take-off(PTO)damping coefficient,wave periods,and draft/displacement on the hydrodynamic performance of the two structure shapes were simulated and investigated.The results reveal that the L type performs better in shorter wave periods,and the trapezoidal type exhibits a higher CWR in intermediate wave periods.This study offers knowledge of the design and protection of the two WEC-FB types.展开更多
Single-photon sensors are novel devices with extremely high single-photon sensitivity and temporal resolution.However,these advantages also make them highly susceptible to noise.Moreover,single-photon cameras face sev...Single-photon sensors are novel devices with extremely high single-photon sensitivity and temporal resolution.However,these advantages also make them highly susceptible to noise.Moreover,single-photon cameras face severe quantization as low as 1 bit/frame.These factors make it a daunting task to recover high-quality scene information from noisy single-photon data.Most current image reconstruction methods for single-photon data are mathematical approaches,which limits information utilization and algorithm performance.In this work,we propose a hybrid information enhancement model which can significantly enhance the efficiency of information utilization by leveraging attention mechanisms from both spatial and channel branches.Furthermore,we introduce a structural feature enhance module for the FFN of the transformer,which explicitly improves the model's ability to extract and enhance high-frequency structural information through two symmetric convolution branches.Additionally,we propose a single-photon data simulation pipeline based on RAW images to address the challenge of the lack of single-photon datasets.Experimental results show that the proposed method outperforms state-of-the-art methods in various noise levels and exhibits a more efficient capability for recovering high-frequency structures and extracting information.展开更多
The capture of CO_(2)from CO_(2)/H_(2)gas mixtures in syngas is a crucial issue for hydrogen production from steam methane reforming in industry,as the presence of CO_(2)directly affects the purity of H_(2).A combinat...The capture of CO_(2)from CO_(2)/H_(2)gas mixtures in syngas is a crucial issue for hydrogen production from steam methane reforming in industry,as the presence of CO_(2)directly affects the purity of H_(2).A combination of a high-throughput screening method and grand canonical Monte Carlo simulation was utilized to evaluate and screen 1725 metal–organic frameworks(MOFs)in detail as a means of determining their adsorption performance for CO_(2)/H_(2)gas mixtures.The adsorption and separation performance of double-linker MOFs was comprehensively evaluated using eight evaluation indicators,namely,the largest cavity diameter,accessible surface area,pore occupied accessible volume,porosity,adsorption selectivity,working capacity,adsorbent performance score and percent regeneration.Six optimal performance frameworks were screened to further study their single-component adsorption and binary competitive adsorption of CO_(2)/H_(2)respectively.The CO_(2)adsorption selectivity at different CO_(2)/H_(2)feed ratios was also evaluated,which indicated their excellent adsorption and separation performance.The microscopic adsorption mechanisms for CO_(2)and H_(2)at the molecular level were investigated by analyzing the radial distribution function and density distribution.This study may provide directional guidance and reference for subsequent experiments on the adsorption and separation of CO_(2)/H_(2).展开更多
Health information spreads rapidly,which can effectively control epidemics.However,the swift dissemination of information also has potential negative impacts,which increasingly attracts attention.Message fatigue refer...Health information spreads rapidly,which can effectively control epidemics.However,the swift dissemination of information also has potential negative impacts,which increasingly attracts attention.Message fatigue refers to the psychological response characterized by feelings of boredom and anxiety that occur after receiving an excessive amount of similar information.This phenomenon can alter individual behaviors related to epidemic prevention.Additionally,recent studies indicate that pairwise interactions alone are insufficient to describe complex social transmission processes,and higher-order structures representing group interactions are crucial.To address this,we develop a novel epidemic model that investigates the interactions between information,behavioral responses,and epidemics.Our model incorporates the impact of message fatigue on the entire transmission system.The information layer is modeled using a static simplicial network to capture group interactions,while the disease layer uses a time-varying network based on activity-driven model with attractiveness to represent the self-protection behaviors of susceptible individuals and self-isolation behaviors of infected individuals.We theoretically describe the co-evolution equations using the microscopic Markov chain approach(MMCA)and get the epidemic threshold.Experimental results show that while the negative impact of message fatigue on epidemic transmission is limited,it significantly weakens the group interactions depicted by higher-order structures.Individual behavioral responses strongly inhibit the epidemic.Our simulations using the Monte Carlo(MC)method demonstrate that greater intensity in these responses leads to clustering of susceptible individuals in the disease layer.Finally,we apply the proposed model to real networks to verify its reliability.In summary,our research results enhance the understanding of the information-epidemic coupling dynamics,and we expect to provide valuable guidance for managing future emerging epidemics.展开更多
(Mg,Fe)SiO_(3) is primarily located in the mantle and has a substantial impact on geophysical and geochemical processes.Here,we employ molecular dynamics simulations to investigate the structural and transport propert...(Mg,Fe)SiO_(3) is primarily located in the mantle and has a substantial impact on geophysical and geochemical processes.Here,we employ molecular dynamics simulations to investigate the structural and transport properties of(Mg,Fe)SiO_(3) with varying iron contents at temperatures up to 5000 K and pressures up to 135 GPa.We thoroughly examine the effects of pressure,temperature,and iron content on the bond lengths,coordination numbers,viscosities,and electrical conductivities of(Mg,Fe)SiO_(3).Our calculations indicate that the increase of pressure leads to the shortening of the O-O and Mg-O bond lengths,while the Si-O bond lengths exhibit the initial increase with pressure up to 40 GPa,after which they are almost unchanged.The coordination numbers of Si transition from four-fold to six-fold and eventually reach eight-fold coordination at 135 GPa.The enhanced pressure causes the decrease of the diffusion coefficients and the increase of the viscosities of(Mg,Fe)SiO_(3).The increased temperatures slightly decrease the coordination numbers and viscosities,as well as obviously increase the diffusion coefficients and electrical conductivities of(Mg,Fe)SiO_(3).Additionally,iron doping facilitates the diffusion of Si and O,reduces the viscosities,and enhances the electrical conductivities of(Mg,Fe)SiO_(3).These findings advance fundamental understanding of the structural and transport properties of(Mg,Fe)SiO_(3) under high temperature and high pressure,which provide novel insights for unraveling the complexities of geological processes within the Earth's mantle.展开更多
基金supported by the National Key Research and Development Program of China(Nos.2021YFF0500300 and 2023YFB3711300)the Strategic Research and Consulting Project of the Chinese Academy of Engineering(Nos.2023-XZ-90 and 2023-JB-09-10).
文摘Establishing a base on the Moon is one of the new goals of human lunar exploration in recent years.Sintered lunar regolith is one of the most potential building materials for lunar bases.The physical,mechanical and thermal properties of sintered lunar regolith are vital performance indices for the structural design of a lunar base and analysis of many critical mechanical and thermal issues.In this study,the HUST-1 lunar regolith simulant(HLRS)was sintered at 1030,1040,1050,1060,1070,and 1080℃.The effect of sintering temperature on the compressive strength was investigated,and the exact value of the optimum vacuum sintering temperature was determined between 1040 and 1060℃.Then,the microstructure and material composition of vacuum sintered HLRS at different temperatures were characterized.It was found that the sintering temperature has no significant effect on the mineral composition in the temperature range of 1030-1080℃.Besides,the heat capacity,thermal conductivity,and coefficient of thermal expansion(CTE)of vacuum sintered HLRS at different temperatures were investigated.Specific heat capacity of sintered samples increases with the increase of test temperature within the temperature range from-75 to 145℃.Besides,the thermal conductivity of the sintered sample is proportional to density.Finally,the two temperatures of 1040 and 1050℃were selected for a more detailed study of mechanical properties.The results showed that compressive strength of sintered sample is much higher than tensile strength.This study reveals the effects of sintering temperature on the physical,mechanical and thermal properties of vacuum sintered HLRS,and these material parameters will provide support for the construction of future lunar bases.
基金supported by the PolyU RCDSE projects(Nos.P0049221 and P0041304)We would like to express our sincere gratitude to Prof.Feng Li and Dr.Siqi Zhou from Beihang University for providing us with the BH-1 simulant,which served as the crucial reference for the PolyU-1 simulant.We would like to thank the support from the National Natural Science Foundation of China(No.42241103)the Key Research Program of the Institute of Geology and Geophysics,Chinese Academy of Sciences(No.IGGCAS-202101)。
文摘Leading national space exploration agencies and private enterprises are actively engaged in lunar exploration initiatives to accomplish manned lunar landings and establish permanent lunar bases in the forthcoming years.With limited access to lunar surface materials on Earth,lunar regolith simulants are crucial for lunar exploration research.The Chang’e-5(CE-5)samples have been characterized by state-of-the-art laboratory equipment,providing a unique opportunity to develop a high-quality lunar regolith simulant.We have prepared a high-fidelity PolyU-1 simulant by pulverizing,desiccating,sieving,and blending natural mineral materials on Earth based on key physical,mineral,and chemical characteristics of CE-5 samples.The results showed that the simulant has a high degree of consistency with the CE-5 samples in terms of the particle morphology,mineral and chemical composition.Direct shear tests were conducted on the simulant,and the measured internal friction angle and cohesion values can serve as references for determining the mechanical properties of CE-5 lunar regolith.The PolyU-1 simulant can contribute to experimental studies involving lunar regolith,including the assessment of interaction between rovers and lunar regolith,as well as the development of in-situ resource utilization(ISRU)technologies.
基金supported by the National Natural Science Foundation of China(Nos.41902273,41772338)the China Postdoctoral Science Foundation(No.2019M661986)+2 种基金the Natural Science Foundation of Jiangsu Province(No.BK20190637)and the Jiangsu Planned Projects for Postdoctoral Research Funds(No.2019K194)support by the State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology(Nos.Z19007,Z19009).
文摘Lunar in-situ resource utilization(ISRU)has been put on the agenda by many countries.Due to the special material nature and low gravity environment,the lunar regolith demonstrates significantly different behavior from terrestrial geomaterials.However,the systematic understanding of its geotechnical behavior is now seriously restricted by the scarcity of lunar regolith and the difficulty in simulating lunar gravity.A new lunar regolith simulant,termed as China University of Mining and Technology Number One(CUMT-1),has been developed to recover properties of the lunar regolith and simulate the lunar gravity by adopting the recently advanced geotechnical magnetic-similitude-gravity model testing(GMMT)method.The CUMT-1 simulant was prepared by reproducing the in-situ formation and fragmentation of the lunar matrix,which plays a key role in the irregular particle morphology.The mineralogical compositions,particle morphology and gradation,specific gravity,bulk density,void ratio,shear strength,and compressibility were determined.After quantifying the magnetization and magnetic-similitude-gravity characteristics,an application of the cone penetration resistance under low gravity was further given.The obtained results are compared to the values known for lunar regolith samples and other simulants,which demonstrates promising characteristics for use in geotechnical engineering-based and scientificbased applications,especially considering the influence of lunar gravity.
基金supported by the National Natural Science Foundation of China(Nos.U2013603 and 52225403)the Program for Guangdong Introducing Innovative and Entrepreneurial Teams(No.2019ZT08G315)the Shenzhen National Science Fund for Distinguished Young Scholars(No.RCJC20210706091948015).
文摘With the increasing scarcity of Earth’s resources and the development of space science and technology,the exploration, development, and utilization of deep space-specific material resources(minerals, water ice, volatile compounds, etc.) are not only important to supplement the resources and reserves on Earth but also provide a material foundation for establishing extraterrestrial research bases. To achieve large depth in-situ condition-preserved coring(ICP-Coring) in the extreme lunar environment, first, lunar rock simulant was selected(SZU-1), which has a material composition, element distribution, and physical and mechanical properties that are approximately equivalent to those of lunar mare basalt. Second, the influence of the lunar-based in-situ environment on the phase, microstructure, and thermal physical properties(specific heat capacity, thermal conductivity, thermal diffusivity, and thermal expansion coefficient)of SZU-1 was explored and compared with the measured lunar rock data. It was found that in an air atmosphere, low temperature has a more pronounced effect on the relative content of olivine than other temperatures, while in a vacuum atmosphere, the relative contents of olivine and anorthite are significantly affected only at temperatures of approximately-20 and 200 ℃. When the vacuum level is less than100 Pa, the contribution of air conduction can be almost neglected, whereas it becomes dominant above this threshold. Additionally, as the testing temperature increases, the surface of SZU-1 exhibits increased microcracking, fracture opening, and unevenness, while the specific heat capacity, thermal conductivity,and thermal expansion coefficient show nonlinear increases. Conversely, the thermal diffusivity exhibits a nonlinear decreasing trend. The relationship between thermal conductivity, thermal diffusivity, and temperature can be effectively described by an exponential function(R^(2)>0.98). The research results are consistent with previous studies on real lunar rocks. These research findings are expected to be applied in the development of the test and analysis systems of ICP-Coring in a lunar environment and the exploration of the mechanism of machine-rock interaction in the in-situ drilling and coring process.
基金supported by National Natural Science Foundation of China(No.51877205)Fundamental Research Funds for the Central Universities(No.buct201906)+1 种基金the State Key Laboratory of NBC Protection for Civilian(No.SKLNBC2021-0X)Beijing Nova Program(No.2022015)。
文摘Low-temperature plasma is a green and high-efficiency technology for chemical warfare agent(CWA)decontamination.However,traditional plasma devices suffer from the problems of highpower composition and large power-supply size,which limit their practical applications.In this paper,a self-driven microplasma decontamination system,induced by a dielectric-dielectric rotary triboelectric nanogenerator(dd-r TENG),was innovatively proposed for the decontamination of CWA simulants.The microplasma was characterized via electrical measurements,optical emission spectra and ozone concentration detection.With an output voltage of-3460 V,the dd-r TENG can successfully excite microplasma in air.Reactive species,such as OH,O(1D),Hαand O3were detected.With input average power of 0.116 W,the decontamination rate of 2-chloroethyl ethyl sulfide reached 100%within 3 min of plasma treatment,while the decontamination rates of malathion and dimethyl methylphosphonate reached(65.92±1.65)%and(60.88±1.92)%after 7 min of plasma treatment,respectively.In addition,the decontamination rates gradually decreased with the increase in the simulant concentrations.Typical products were identified and analyzed.This study demonstrates the broad spectrum and feasibility of the dd-r TENG-microplasma for CWA elimination,which provides significant guidance for their practical applications in the future.
文摘The response of biological phantoms against high velocity impact is actively sought for applications in defense,space,soft robotics and sensing.Towards this end,we study the ballistic response of silicone based skin simulant against fragment impact.Using a pneumatic gas gun setup,six chisel-nosed and three regular shaped(sphere,cylinder,and cube)fragments were impacted on the skin simulant.The resulting skin simulant response was studied in terms of ballistic limit velocities,energy densities,failure pattern,and the mechanics of interaction.The results indicate that the shape of the fragment affects the ballistic limit velocities.The ballistic limit velocities,energy densities of the chisel-nosed fragment simulating projectiles were relatively insensitive to the size(mass),except for the smallest(0.16 g)and largest(2.79 g)chisel-nosed fragment.For the same size(1 g),ballistic limit velocities and failure are dependent on the shape of the fragment.The skin simulant failed by combined plugging and elastic hole enlargement.Failure in the spherical fragment was dominated by the elastic hole enlargement,whereas plugging failure was dominant in all other fragments.The spherical,cylindrical,and chisel-nosed fragments created circular cavities,and the cubical fragment created a square cavity.In the case of the spherical fragment,slipping of the fragment within the skin simulant was seen.Cubical fragments created lateral cracks emanating from the corners of the square cavity.Interestingly,for all the fragments,the maximum deformation corresponding to the perforation was lower than the non-perforation indicating rate dependent,stress driven failure.The maximum deformation was also dependent on the shape of the fragment.Overall,these results provide unique insights into the mechanical response of a soft simulant against ballistic impact.Results have utility in the calibration and validation of computational models,design of personal protective equipment,and antipersonnel systems.
基金Sponsored by the National Natural Science Foundation of China(10832003,11076032)the National Basic Research Program of China(613830202)the Program for New Century Excellent Talents(NCET-06-0159)
文摘Punch loading is a loading scenario to study the fracture mechanism of materials at low strain rates.In this paper,three punch loading experimental patterns were chosen for the study of compressional punch loading.A polymer bonded explosive（PBX） simulant was experimentally studied using the digital image correlation（DIC） method.The displacement and strain fields were obtained and the fracture behavior and failure mechanisms of samples were investigated under different punch loading conditions.Moreover,scanning electron microscope（SEM） was used to examine the region of the plastic flow and the damage in the material.The formation of slip bands,shear displacement and fracture of the hard phase particle,were observed on the boundary of the dead zone due to the large shear strains.
文摘The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.
文摘Thermally activated delayed fluorescence(TADF)molecules have outstanding potential for applications in organic light-emitting diodes(OLEDs).Due to the lack of systematic studies on the correlation between molecular structure and luminescence properties,TADF molecules are far from meeting the needs of practical applications in terms of variety and number.In this paper,three twisted TADF molecules are studied and their photophysical properties are theoretically predicted based on the thermal vibrational correlation function method combined with multiscale calculations.The results show that all the molecules exhibit fast reverse intersystem crossing(RISC)rates(kRISC),predicting their TADF luminescence properties.In addition,the binding of DHPAzSi as the donor unit with different acceptors can change the dihedral angle between the ground and excited states,and the planarity of the acceptors is positively correlated with the reorganization energy,a property that has a strong influence on the non-radiative process.Furthermore,a decrease in the energy of the molecular charge transfer state and an increase in the kRISC were observed in the films.This study not only provides a reliable explanation for the observed experimental results,but also offers valuable insights that can guide the design of future TADF molecules.
基金supported by the Science and Technology Project of State Grid Corporation of China(5419-202199552A-0-5-ZN).
文摘Explorations into new electrolytes have highlighted the critical impact of solvation structure on battery performance,Classical molecular dynamics(CMD)using semi-empirical force fields has become an essential tool for simulating solvation structures.However,mainstream force fields often lack accuracy in describing strong ion-solvent interactions,causing disparities between CMD simulations and experimental observations.Although some empirical methods have been employed in some of the studies to address this issue,their effectiveness has been limited.Our CMD research,supported by quantum chemical calculations and experimental data,reveals that the solvation structure is influenced not only by the charge model but also by the polarization description.Previous empirical approaches that focused solely on adjusting ion-solvent interaction strengths overlooked the importance of polarization effects.Building on this insight,we propose integrating the Drude polarization model into mainstream force fields and verify its feasibility in carbonate,ether,and nitrile electrolytes.Our experimental results demonstrate that this approach significantly enhances the accuracy of CMD-simulated solvation structures.This work is expected to provide a more reliable CMD method for electrolyte design,shielding researchers from the pitfalls of erroneous simulation outcomes.
基金supported by the National Natural Science Foundation of China(Grant Nos.51978672 and 52308335)the Natural Science Funding of Hunan Province(Grant No.2023JJ41054)the Natural Science Research Project of Anhui Educational Committee(Grant No.2023AH051170)。
文摘Understanding the reinforcement effect of the newly developed prestressed reinforcement components(PRCs)(a system composed of prestressed steel bars(PSBs),protective sleeves,lateral pressure plates(LPPs),and anchoring elements)is technically significant for the rational design of prestressed subgrade.A three-dimensional finite element model was established and verified based on a novel static model test and utilized to systematically analyze the influence of prestress levels and reinforcement modes on the reinforcement effect of the subgrade.The results show that the PRCs provide additional confining pressure to the subgrade through the diffusion effect of the prestress,which can therefore effectively improve the service performance of the subgrade.Compared to the unreinforced conventional subgrades,the settlements of prestressreinforced subgrades are reduced.The settlement attenuation rate(Rs)near the LPPs is larger than that at the subgrade center,and increasing the prestress positively contributes to the stability of the subgrade structure.In the multi-row reinforcement mode,the reinforcement effect of PRCs can extend from the reinforced area to the unreinforced area.In addition,as the horizontal distance from the LPPs increases,the additional confining pressure converted by the PSBs and LPPs gradually diminishes when spreading to the core load bearing area of the subgrade,resulting in a decrease in the Rs.Under the singlerow reinforcement mode,PRCs can be strategically arranged according to the local areas where subgrade defects readily occurred or observed,to obtain the desired reinforcement effect.Moreover,excessive prestress should not be applied near the subgrade shoulder line to avoid the shear failure of the subgrade shoulder.PRCs can be flexibly used for preventing and treating various subgrade defects of newly constructed or existing railway lines,achieving targeted and classified prevention,and effectively improving the bearing performance and deformation resistance of the subgrade.The research results are instructive for further elucidating the prestress reinforcement effect of PRCs on railway subgrades.
基金supported by National Natural Science Foundation of China(No.11975261)。
文摘In order to support the physical research on the EAST tokamak,a new positive ion source with designed beam energy of 120 keV was proposed to be developed.Accelerator structure is one of the key components of the ion source.Through the finite element analysis method,the electrostatic analyses of insulators and grid plates were carried out,the material and structure parameters of insulators were determined.The maximum electric field around each insulator is about 4 kV/mm,and the maximum electric field between grids is about 14 kV/mm,which can meet the 120 keV withstand voltage holding.The insulation system for the positive ion source accelerator with 120 keV is designed,and the connection and basic parameters of insulators and support flanges are analyzed and determined.
基金Project supported financially by the National Natural Science Foundation of China (Grant No. 52372100)the National Key Research and Development Program of China (Grant No. 2019YFA0307900)。
文摘Based on the principles of thermodynamics, we elucidate the fundamental reasons behind the hysteresis of spontaneous polarization in ferroelectric materials during heating and cooling processes. By utilizing the effective Hamiltonian method in conjuction with the phase-field model, we have successfully reproduced the thermal hysteresis observed in ferroelectric materials during phase transitions. The computational results regarding the electrocaloric effect from these two different computational scales closely align with experimental measurements. Furthermore, we analyze how the first-order ferroelectric phase transition gradually diminishes with an increasing applied electric field, exhibiting characteristics of second-order-like phase transition. By employing the characteristic parameters of thermal hysteresis, we have established a pathway for calculations across different computational scales, thereby providing theoretical support for further investigations into the properties of ferroelectric materials through concurrent multiscale simulations.
基金funding support from the National Natural Science Foundation of China (Nos. 42477208 and 52079134)the Natural Science Foundation of Hubei Province, China (No. 2024AFA072)+2 种基金the Youth Innovation Promotion Association CAS (No. 2022332)the National Key R&D Program of China (No. 2024YFF0508203)the Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering Safety (Nos. SKLGME-JBGS2402 and SKLGME022022)。
文摘Accurate acquisition of the rock stress is crucial for various rock engineering applications.The hollow inclusion (HI) technique is widely used for measuring in-situ rock stress.This technique calculates the stress tensor by measuring strain using an HI strain cell.However,existing analytical solutions for stress calculation based on an HI strain cell in a double-layer medium are not applicable when an HI strain cell is used in a three-layer medium,leading to erroneous stress calculations.To address this issue,this paper presents a method for calculating stress tensors in a three-layer medium using numerical simulations,specifically by obtaining a constitutive matrix that relates strain measurements to stress tensors in a three-layer medium.Furthermore,using Latin hypercube sampling (LHS) and orthogonal experimental design strategies,764 groups of numerical models encompassing various stress measurement scenarios have been established and calculated using FLAC^(3D)software.Finally,a surrogate model based on artificial neural network (ANN) was developed to predict constitutive matrices,achieving a goodness of fit (R^(2)) of 0.999 and a mean squared error (MSE) of 1.254.A software program has been developed from this surrogate model for ease of use in practical engineering applications.The method’s accuracy was verified through numerical simulations,analytical solution and laboratory experiment,demonstrating its effectiveness in calculating stress in a three-layer medium.The surrogate model was applied to calculate mining-induced stress in the roadway roof rock of a coal mine,a typical case for stress measurement in a three-layer medium.Errors in stress calculations arising from the use of existing analytical solutions were corrected.The study also highlights the significant errors associated with using double-layer analytical solutions in a three-layer medium,which could lead to inappropriate engineering design.
基金Project supported by the National Natural Science Foundation of China (Grant No. 52271105)。
文摘Uranium–molybdenum(U–Mo) alloys are critical for nuclear power generation and propulsion because of their superior thermal conductivity, irradiation stability, and anti-swelling properties. This study explores the plastic deformation mechanisms of γ-phase U–Mo alloys using molecular dynamics(MD) simulations. In the slip model, the generalized stacking fault energy(GSFE) and the modified Peierls–Nabarro(P–N) model are used to determine the competitive relationships among different slip systems. In the twinning model, the generalized plane fault energy(GPFE) is assessed to evaluate the competition between slip and twinning. The findings reveal that among the three slip systems, the {110}<111>slip system is preferentially activated, while in the {112}<111> system, twinning is favored over slip, as confirmed by MD tensile simulations conducted in various directions. Additionally, the impact of Mo content on deformation behavior is emphasized. Insights are provided for optimizing process conditions to avoid γ → α′′ transitions, thereby maintaining a higher proportion of γ-phase U–Mo alloys for practical applications.
基金Supported by Shandong Provincial Natural Science Foundation,China(ZR2020ME259)Open Fund of Shandong Key Laboratory of Civil Engineering Disaster Prevention and Mitigation(CDPM2021KF21).
文摘Two asymmetric types of floating breakwaters integrated with a wave energy converter(WEC-FBs),a floating square box with a triangle(trapezoidal type)or a wave baffle(L type)attached to its rear side,have been proposed.In this research,the hydrodynamic performance,including capture width ratio(CWR),wave transmission coefficient,heave motion,and force coefficient,were studied and compared between the two types.A numerical simulation model based on the Navier-Stokes equation was employed.The effects of power take-off(PTO)damping coefficient,wave periods,and draft/displacement on the hydrodynamic performance of the two structure shapes were simulated and investigated.The results reveal that the L type performs better in shorter wave periods,and the trapezoidal type exhibits a higher CWR in intermediate wave periods.This study offers knowledge of the design and protection of the two WEC-FB types.
文摘Single-photon sensors are novel devices with extremely high single-photon sensitivity and temporal resolution.However,these advantages also make them highly susceptible to noise.Moreover,single-photon cameras face severe quantization as low as 1 bit/frame.These factors make it a daunting task to recover high-quality scene information from noisy single-photon data.Most current image reconstruction methods for single-photon data are mathematical approaches,which limits information utilization and algorithm performance.In this work,we propose a hybrid information enhancement model which can significantly enhance the efficiency of information utilization by leveraging attention mechanisms from both spatial and channel branches.Furthermore,we introduce a structural feature enhance module for the FFN of the transformer,which explicitly improves the model's ability to extract and enhance high-frequency structural information through two symmetric convolution branches.Additionally,we propose a single-photon data simulation pipeline based on RAW images to address the challenge of the lack of single-photon datasets.Experimental results show that the proposed method outperforms state-of-the-art methods in various noise levels and exhibits a more efficient capability for recovering high-frequency structures and extracting information.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304079,11404094,and 11504088)Science and Technology Research Project of Henan Science and Technology Department(Grant No.182102410076)。
文摘The capture of CO_(2)from CO_(2)/H_(2)gas mixtures in syngas is a crucial issue for hydrogen production from steam methane reforming in industry,as the presence of CO_(2)directly affects the purity of H_(2).A combination of a high-throughput screening method and grand canonical Monte Carlo simulation was utilized to evaluate and screen 1725 metal–organic frameworks(MOFs)in detail as a means of determining their adsorption performance for CO_(2)/H_(2)gas mixtures.The adsorption and separation performance of double-linker MOFs was comprehensively evaluated using eight evaluation indicators,namely,the largest cavity diameter,accessible surface area,pore occupied accessible volume,porosity,adsorption selectivity,working capacity,adsorbent performance score and percent regeneration.Six optimal performance frameworks were screened to further study their single-component adsorption and binary competitive adsorption of CO_(2)/H_(2)respectively.The CO_(2)adsorption selectivity at different CO_(2)/H_(2)feed ratios was also evaluated,which indicated their excellent adsorption and separation performance.The microscopic adsorption mechanisms for CO_(2)and H_(2)at the molecular level were investigated by analyzing the radial distribution function and density distribution.This study may provide directional guidance and reference for subsequent experiments on the adsorption and separation of CO_(2)/H_(2).
基金Project supported by the National Natural Science Foundation of China(Grant Nos.72171136 and 72134004)Humanities and Social Science Research Project,Ministry of Education of China(Grant No.21YJC630157)+1 种基金the Natural Science Foundation of Shandong Province(Grant No.ZR2022MG008)Shandong Provincial Colleges and Universities Youth Innovation Technology of China(Grant No.2022RW066)。
文摘Health information spreads rapidly,which can effectively control epidemics.However,the swift dissemination of information also has potential negative impacts,which increasingly attracts attention.Message fatigue refers to the psychological response characterized by feelings of boredom and anxiety that occur after receiving an excessive amount of similar information.This phenomenon can alter individual behaviors related to epidemic prevention.Additionally,recent studies indicate that pairwise interactions alone are insufficient to describe complex social transmission processes,and higher-order structures representing group interactions are crucial.To address this,we develop a novel epidemic model that investigates the interactions between information,behavioral responses,and epidemics.Our model incorporates the impact of message fatigue on the entire transmission system.The information layer is modeled using a static simplicial network to capture group interactions,while the disease layer uses a time-varying network based on activity-driven model with attractiveness to represent the self-protection behaviors of susceptible individuals and self-isolation behaviors of infected individuals.We theoretically describe the co-evolution equations using the microscopic Markov chain approach(MMCA)and get the epidemic threshold.Experimental results show that while the negative impact of message fatigue on epidemic transmission is limited,it significantly weakens the group interactions depicted by higher-order structures.Individual behavioral responses strongly inhibit the epidemic.Our simulations using the Monte Carlo(MC)method demonstrate that greater intensity in these responses leads to clustering of susceptible individuals in the disease layer.Finally,we apply the proposed model to real networks to verify its reliability.In summary,our research results enhance the understanding of the information-epidemic coupling dynamics,and we expect to provide valuable guidance for managing future emerging epidemics.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12174352 and 12111530103)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(Grant No.G1323523065)。
文摘(Mg,Fe)SiO_(3) is primarily located in the mantle and has a substantial impact on geophysical and geochemical processes.Here,we employ molecular dynamics simulations to investigate the structural and transport properties of(Mg,Fe)SiO_(3) with varying iron contents at temperatures up to 5000 K and pressures up to 135 GPa.We thoroughly examine the effects of pressure,temperature,and iron content on the bond lengths,coordination numbers,viscosities,and electrical conductivities of(Mg,Fe)SiO_(3).Our calculations indicate that the increase of pressure leads to the shortening of the O-O and Mg-O bond lengths,while the Si-O bond lengths exhibit the initial increase with pressure up to 40 GPa,after which they are almost unchanged.The coordination numbers of Si transition from four-fold to six-fold and eventually reach eight-fold coordination at 135 GPa.The enhanced pressure causes the decrease of the diffusion coefficients and the increase of the viscosities of(Mg,Fe)SiO_(3).The increased temperatures slightly decrease the coordination numbers and viscosities,as well as obviously increase the diffusion coefficients and electrical conductivities of(Mg,Fe)SiO_(3).Additionally,iron doping facilitates the diffusion of Si and O,reduces the viscosities,and enhances the electrical conductivities of(Mg,Fe)SiO_(3).These findings advance fundamental understanding of the structural and transport properties of(Mg,Fe)SiO_(3) under high temperature and high pressure,which provide novel insights for unraveling the complexities of geological processes within the Earth's mantle.
