15 results about "Radial distribution function" patented technology

The invention relates to the technical field of nanofluid enhanced heat transfer simulation, in particular to a molecular dynamics-based mixed nanofluid heat transfer characteristic analysis method, which comprises the following steps of: constructing a molecular model comprising copper, graphene nanoparticles and an ionic liquid / water mixed base solution, and calculating the heat transfer characteristic of the mixed nanofluid through a distribution potential function and a periodic boundary condition; and performing energy minimization and molecular dynamic relaxation to achieve thermodynamic equilibrium. A steady-state temperature gradient is established based on the unbalanced molecular dynamics principle, and the thermal conductivity is calculated according to the Fourier law. Microcosmic parameters such as a radial distribution function, mean square displacement and the number of hydrogen bonds are synchronously analyzed, and a coupling mechanism of interaction and heat transfer performance of the nano-particle-base fluid interface is disclosed. According to the method, the heat transfer characteristic of the mixed nanofluid can be clarified on the molecular scale, and an efficient and reliable analysis means is provided for nanofluid screening and design in application of a solar heat collector, a heat management system and the like.

A calculation apparatus for calculating a correlation function from a structural model comprises a structural model acquiring section for acquiring the structural model including a plurality of types of atoms in space, an atomic species setting section for setting a specific atomic species in the structural model, and a correlation function calculating section for calculating the correlation function that is a ratio between a first radial distribution function and a second radial distribution function, wherein the first radial distribution function is a radial distribution function between atoms of the specific atomic species and atoms of the specific atomic species, and the second radial distribution function is a radial distribution function between atoms of the specific atomic species and atoms of two or more types of atomic species including the specific atomic species.

The invention discloses a method for analyzing a fiber and resin interface area based on molecular simulation, and belongs to the field of building a fiber and resin interface model based on a molecular simulation technology, and carrying out geometric optimization and dynamic balance on the interface model; counting and presenting the fiber surface conformation of the interface model; constructing a model of independent resin molecular chains and fibers, and explaining reasons of conformational changes of the resin molecular chains; based on the radial distribution function and the mean square displacement curve, analyzing the interface structure of the interface model and the activity of molecules; and constructing an interface model for interface nanoindentation simulation, and analyzing the stress bearing capacity of different areas of the interface and the motion displacement condition of atoms. According to the method, conformation and performance analysis of the fiber and resin interface are realized, favorable support can be provided for design, optimization and performance prediction of the fiber reinforced composite material, and the method has relatively good practicability.

This invention provides a computing device, method, and program for calculating correlation functions from structural models. [Solution] A computing device 100 for calculating a correlation function from a structural model, comprising: a structural model acquisition unit 110 for acquiring the structural model containing multiple types of atoms in space; an atom species setting unit 120 for setting specific atom species in the structural model; and a correlation function calculation unit 130 for calculating the correlation function which is the ratio of a first radial distribution function to a second radial distribution function, wherein the first radial distribution function is the radial distribution function between atoms of the specific atom species and atoms of the specific atom species, and the second radial distribution function is the radial distribution function between atoms of the specific atom species and atoms of two or more atom species including the specific atom species.

The invention relates to the field of metal-based composite materials, and provides a metal-based composite material optimization method based on dynamic reverse design, which comprises the following steps: S1, an early-stage preparation stage of a model: establishing different particle distribution configurations of a particle reinforced metal-based composite material at high flux by utilizing an Abaq us plug-in; s2, a data set construction stage: quantizing the long-range / short-range order degree of an enhancement body through a translation sequence parameter and a radial distribution function, and generating an enhancement body configuration and a random variant thereof; s3, a forward prediction stage: constructing a BPNN-CL model by adopting a back propagation neural network fused with continuous learning, and dynamically mapping the material / structure feature vectors to mechanical properties; and S4, a reverse optimization stage: chaos disturbance, dynamic partition monitoring and an elitism strategy are integrated into an NSGA-I algorithm to form an NSGA-I-PMCP optimizer, and multi-target optimization is carried out by taking BPNN-CL as a real-time agent model. The problem of reasonably designing a matrix, an interface product and a reinforcement of the particle reinforced metal matrix composite to synergistically improve the strength and the toughness of the metal matrix composite is solved.

The invention discloses an intelligent design method of a high-strength single-phase body-centered cubic high-entropy alloy based on lattice distortion engineering, which comprises the following steps of: constructing a component space, carrying out molecular dynamics simulation and structure screening, screening out components with a stable single-phase body-centered cubic structure, and carrying out high-strength single-phase body-centered cubic high-entropy alloy design. The strongest peak intensity of an atom radial distribution function is innovatively adopted as a lattice distortion quantitative index, a component-performance associated data set is constructed in combination with molecular dynamics simulation, and a hybrid machine learning model fusing a generative adversarial network and Bayesian optimization is developed. According to the method, alloy components with large lattice distortion can be quickly and accurately screened in a more than trillion-level component space. According to the method, the limitation of a traditional trial and error method is broken through, the screening efficiency is improved in an exponential level, screened components show significant lattice distortion, the obtained alloy keeps a single centered cubic phase structure, the room-temperature yield strength reaches 1,300 MPa, and an efficient and reliable new normal form is provided for high-toughness material design in the fields of aerospace, nuclear energy equipment and the like.

The application relates to a chemical short-range order measurement method and system based on an atomic pair distribution function, and the method comprises the following steps: performing a total scattering experiment on a polycrystalline powder sample to obtain total scattering data, a scattering function and an atomic pair distribution function; based on the total scattering data, an initial three-dimensional atomic structure model is constructed; further, the initial three-dimensional atomic structure model is fitted and reconstructed by taking minimization of a fitting goodness factor as a target, so that a three-dimensional atomic structure model after fitting and reconstruction is obtained; according to the three-dimensional atomic structure model after fitting and reconstruction, a radial distribution function and a bulk average distribution concentration are calculated, and a chemical short-range order parameter calculation cutoff is set according to a near-neighbor atomic cutoff distance; further, the probability of an atom finding other types of atoms under the calculation cutoff is calculated; and the chemical short-range order parameter is calculated based on the probability and the bulk average distribution concentration. Compared with the prior art, the application has the advantage of wide application scenarios.

The invention provides an aluminum foil surface oxide dielectric constant calculation method and system, and the method comprises the steps: simulating the surface reaction of aluminum and water through reaction molecular dynamics, calculating the radial distribution function of the surface of a model after the reaction reaches equilibrium, and carrying out the systematic comparison of the radial distribution function with a known oxide structure model in a standard crystallography database. A known crystal model highly matched with the structural characteristics of a simulated product is screened out, complete crystallographic parameters of the model are extracted, and the dielectric constant of a corresponding substance is solved by using a first principle. According to the method, cross-scale connection from a surface reaction process to dielectric property calculation is realized, and the accuracy of dielectric constant calculation is improved; the problems of performance uncertainty and the like of oxidation films generated by the aluminum foil in different traditional formation processes are solved, and a new solution is provided for preparation of high-performance electronic information materials.

The invention provides a method for calculating the minimum molecule occupied area of a surfactant on an oil-water interface, an oil-water interface model with different adsorption capacities is constructed through full-atom molecular dynamics (MD) simulation, and a new method taking an oil layer thickness stable point and a surfactant intermolecular radial distribution function (RDF) peak saturation point as dual criteria is provided. According to the method, the supersaturation adsorption interference on the total interface thickness parameter is effectively eliminated, and the real saturation state of the ordered planar single layer formed by the surfactant is accurately positioned. According to the method, the minimum molecule occupied area Amin can be accurately calculated without synthesizing a solid sample, the prediction precision is matched with that of a neutron diffraction experiment, and a low-cost and high-precision theoretical tool is provided for molecular design and performance preliminary screening of a novel surfactant.

The invention relates to a chemical short-distance ordered measurement method and system based on an atom pair distribution function, and the method comprises the steps: carrying out a total scattering experiment on a polycrystalline powder sample, and obtaining total scattering data, a scattering function and the atom pair distribution function; constructing an initial three-dimensional atomic structure model based on the total scattering data; further performing fitting reconstruction on the initial three-dimensional atomic structure model by taking minimization of the fitting high-quality factor as a target to obtain a three-dimensional atomic structure model after fitting reconstruction; according to the fitted and reconstructed three-dimensional atomic structure model, calculating a radial distribution function and a volume phase average distribution concentration, and setting chemical short-range ordered parameters according to a neighbor atom truncation distance to calculate truncation; further calculating the probability of finding other types of atoms under the calculation truncation of the atoms; and calculating a chemical short-range order parameter based on the probability and the volume phase average distribution concentration. Compared with the prior art, the method has the advantage of wide application scenes.

The application discloses a method for modifying asphalt with graphene based on molecular dynamics simulation, which comprises the following steps: constructing graphene molecular amorphous cell model, asphalt molecular amorphous cell model and graphene modified asphalt molecular amorphous cell model by using modeling software (Materials Studio), respectively performing molecular dynamics simulation on the models, calculating cohesive energy density and solubility parameter by using the Cohesive Energy Density function in the Forcite module, calculating interaction energy by using the Energy function in the Forcite module, calculating mechanical properties by using the Mechanical Properties function in the Forcite module, and analyzing the radial distribution function of each component in the asphalt molecular system and the graphene modified asphalt molecular system by using the Analysis function in the Forcite module. The application can more essentially explain the interaction between graphene material and matrix asphalt material from the molecular angle, can directly judge the performance of the graphene modified asphalt material, and provides a theoretical basis for the research and development of the graphene modified asphalt.

The present invention reduces workload when optimizing a polymer mixture. This reaction index calculation device comprises: a molecular dynamics calculation unit that calculates molecular dynamics in a system comprising a mixture of a first model and a second model, which are models of a first compound and a second compound constituting polymer mixtures; an existence probability calculation unit that calculates, during the molecular dynamics calculation, using a radial distribution function, a probability of existence at each interatomic distance for two atoms involved in the reaction between the first compound and the second compound; a sum total calculation unit that calculates a sum total up to the first peak in the calculated probability of existence, as a first index value indicating reactivity when the first compound and the second compound are mixed; and a first output unit that, when the first index value indicating the reactivity is calculated for a plurality of combinations of the first compound and the second compound, outputs the first index value in association with each combination.

The invention discloses a multi-parameter confinement simulation method of subsurface layer'fusion type 'growth in a fourth growth mode, and belongs to the field of material simulation and calculation. According to the method, on the basis of molecular dynamics simulation software LAMMPS, the fusion type growth behavior of high-entropy alloy atoms on a substrate subsurface layer in the ion beam assisted deposition process is simulated by regulating and controlling the energy, direction, size and flux of deposition atoms. The method specifically comprises the following steps: establishing a single-crystal or amorphous substrate model of the high-entropy alloy FeCoNiCrMn; setting an MEAM potential function; by regulating and controlling a deposition area, incident energy and flux, injection and nucleation of atoms on the subsurface layer are achieved; a subsurface layer forming process is visualized by using a radial distribution function, kinetic energy analysis, potential energy analysis and stress analysis. The method breaks through the limitation of a traditional surface growth mode, successfully simulates and verifies a fourth film growth mode different from a traditional layered mode, an island mode and a layer-island composite mode, realizes growth from the inside of the substrate to the outside, and provides a theoretical guidance and simulation platform for low-temperature and high-quality preparation of the high-entropy alloy film.

The invention belongs to the technical field of molecular dynamics simulation, and provides a coating surface hydration layer parallel analysis method and system based on molecular dynamics, and the method comprises the steps: obtaining a molecular dynamics model of a surface hydration layer; performing trajectory segmentation on the obtained molecular dynamics model to obtain a plurality of segmentation trajectories; automatically generating an analysis script of the segmentation tracks according to the plurality of obtained segmentation tracks; the analysis scripts of the multiple segmentation tracks are executed in parallel, and in the parallel execution process, the radial distribution function, the orientation distribution function, the hydrogen bond structure, the mean square displacement, the average residence time and the water binding site data of the surface hydration layer in each segmentation track are obtained; and analyzing the space structure of the surface hydration layer, the interaction directionality of water molecules and the surface, the strength of a hydrogen bond network and the dynamic property of the hydration layer to finish parallel analysis of the surface hydration layer of the coating based on molecular dynamics.

The invention discloses a phase structure identification method of a fluorite structure polycrystal multiphase body, and mainly solves the problems of incomplete phase identification and unclear component statistics of a fluorite structure ferroelectric body in the prior art. According to the scheme, the method comprises the following steps: 1) based on an atomic structure of a standard fluorite structure ferroelectric, modeling unit cell structures of an M phase, a T phase, a C phase and a PO phase; 2) summarizing an atomic structure descriptor, and determining a phase structure judgment standard based on the descriptor; 3) on the basis of neighbor atom identification, determining a neighbor atom identification radius through a radial distribution function of a multiphase structure, and respectively calculating coordination number, bond length and bond angle; the method comprises the following steps of (1) carrying out primary division on atoms through atomic coordination numbers, distinguishing a T phase and a C phase based on bond length, distinguishing an M phase and a PO phase based on bond angle, and introducing an unknown structure for characterization, and (5) completing quantitative statistics and visualization of a local region, and can obviously improve the recognition accuracy of various phase structures, and realize phase structure statistics and visualization analysis.