13 results about "Elementary reaction" patented technology

A kind of zirconium alloy water environment corrosion microscopic mechanism analysis method based on ab initio molecular dynamics, 1, construct the multi-phase interface model of metal substrate model and corrosion medium layer model combination, obtain the size information of simulation box;2, set simulation parameters for multi-phase interface model;3, carry out geometry structure optimization to multi-phase interface model and eliminate local internal stress, then carry out ab initio molecular dynamics simulation, obtain atomic evolution track and corrosion product structure;4, carry out data post-processing and statistical analysis to ab initio molecular dynamics simulation result, obtain corrosion elementary reaction path and calculate reaction energy barrier, the interaction mechanism of corrosion group and surface is analyzed by DFT method.The method can complete accurate zirconium alloy corrosion process dynamic simulation under periodic boundary condition, has higher calculation precision and is more reasonable to the description of interatomic force in system, and can also analyze the interaction mechanism between alloy and corrosion medium from atomic electronic scale.

The invention provides a dynamic Monte Carlo simulation method for RAFT polymerization reaction, a storage medium and a computer program, the simulation method is used for modeling the dynamic process of each step of primitive reaction of the RAFT polymerization reaction, and the dynamic Monte Carlo simulation result is obtained based on the occurrence probability of each primitive reaction in the reaction process. The change of the molecular number and structure of reactants and products (including intermediate products and final products) along with the reaction time can be obtained, the structure information of more polymer chains can be obtained, and the method can be used for researching the influence of different reactant feeding, reaction temperature and time on the structure and distribution of the RAFT polymerization product. Moreover, in the dynamic Monte Carlo simulation method of the RAFT polymerization reaction provided by the embodiment of the invention, each monomeric unit of a long-chain molecule in the current primitive reaction is represented by an identifier, and the identifiers of all the monomeric units of the long-chain molecule are stored in the storage table according to the molecular structure of the long-chain molecule, in other words, the storage table only stores the identifier and does not need to store each monomer unit of the long-chain molecule, so that the efficiency of the dynamic Monte Carlo simulation method for the RAFT polymerization reaction is greatly improved.

The present application relates to a kind of molecular structure perception chemical reaction kinetics equation symbol regression method, for solving the problem that existing symbol regression technique ignores species chemical information, causes poor modeling effectiveness.The method adopts encoder-decoder architecture, and the encoding part is provided with double branch: one branch is handled concentration time series by Transformer, another branch utilizes graph neural network to encode molecular graph, and structural characteristics are extracted.After bimodal feature fusion, it is directly returned to the kinetics equation of ordinary differential equation form by the Transformer decoder with cross attention mechanism.Training data is generated by synthesis: based on the data set of elementary reaction, SMILES is converted into molecular graph, and the kinetics equation is deduced according to mass action law, and then concentration trajectory is generated by random sampling and numerical integration, and training sample comprising molecular graph, trajectory and equation is formed.The present application significantly improves the accuracy, interpretability and data utilization efficiency of symbol regression in reaction kinetics modeling.

This invention discloses a method for extracting reaction kinetic parameters from experiments for polymer reaction simulation. The method includes setting the optimization range of elementary reactions and related parameters, obtaining experimental molecular weight distribution curves, setting parameters for a high-dimensional search optimization algorithm and kinetic Monte Carlo simulation parameters, uniformly sampling the combination of reaction kinetic parameters, performing kinetic Monte Carlo simulation to obtain simulated molecular weight distribution curves, calculating the root mean square error between the simulated and experimental molecular weight distribution curves, and updating the combination of reaction kinetic parameters using a high-dimensional search optimization algorithm. This invention can optimize and fit reaction kinetic parameters within the assumed reaction mechanism based solely on the polymer molecular weight distribution curve obtained from a single polymerization experiment. The obtained reaction kinetic parameters can be directly used to predict the results of the next batch of polymerization reactions. Furthermore, through multiple iterations of experiments and simulations, the prediction accuracy of the reaction kinetic parameters can be continuously optimized.

This invention relates to the field of combustion dynamics technology, and provides a method for modeling the combustion dynamics of nano-aluminum particles based on molecular reaction dynamics. The method includes: S1 constructing a nano-aluminum particle model; S2 establishing an oxidation combustion reaction system; S3 analyzing molecular trajectories; S4 extracting reaction paths; S5 determining gas-phase reaction kinetic parameters; S6 determining surface reaction kinetic parameters; S7 constructing a heterogeneous combustion kinetic mechanism; and S8 verifying and outputting simulation results. This invention directly extracts reaction paths through molecular dynamic trajectories in the reaction force field, reducing the subjectivity of relying entirely on artificially preset elementary reactions. It supplements key gas-phase and surface reaction parameters through quantum chemical calculations and density functional theory calculations, improving the physicochemical basis of the mechanism parameters. By coupling gas-phase and surface reactions into a heterogeneous combustion kinetic mechanism, it more completely describes the structural evolution process of aluminum nanoparticles from melting, rapid oxidation, partial oxidation to equilibrium.

The invention discloses a catalyst performance parameter determination method and device. The method comprises the following steps: splitting a target chemical reaction process into a plurality of chemical reaction stages, and the plurality of chemical reaction stages comprise a first-class reaction stage and a second-class reaction stage; acquiring a relationship between the concentration of each element in the element reaction of the first reaction stage and an energy parameter, and determining the energy parameter of the element reaction in the first reaction stage based on the relationship between the concentration of each element in the element reaction of the first reaction stage and the energy parameter; obtaining the relationship between the concentration of each element in the element reaction of the second type of reaction stage and a preset descriptor; determining an energy parameter of the primitive reaction in the second reaction stage according to a relationship between the concentration of each element in the primitive reaction in the second reaction stage and a preset descriptor; and determining the activation energy of the target chemical reaction process according to the energy parameter of the element reaction in the first reaction stage and the energy parameter of the element reaction in the second reaction stage.

The invention provides a method, a device, a storage medium and a system for simplifying a reaction mechanism of mixed fuel. The method comprises the following steps: determining a core mechanism and a global sub-mechanism of each component fuel in the mixed fuel; determining the comprehensive sensitivity coefficient of each element reaction in the combustion reaction process of the mixed fuel according to the core mechanism and the global sub-mechanism of each component fuel; determining a key reaction in the plurality of element reactions according to each comprehensive sensitivity coefficient, and determining a combustion condition corresponding to the key reaction; and determining a first simplified reaction mechanism of the mixed fuel based on a shuffled frog leaping algorithm according to each key reaction and the combustion working condition corresponding to each key reaction. The problems that in the prior art, the reaction mechanism scale of the mixed fuel is large, the calculation complexity is high, and efficient simplification is difficult to achieve while the combustion characteristic precision is guaranteed are solved.

The present application belongs to the field of theoretical catalytic calculation, and particularly relates to a kind of kinetic calculation method for estimating the dehydrogenation activity of zeolite catalyst to alkane.The method comprises the following steps: 1) establishing a network of catalytic elementary reactions, considering the existence of intermediate radicals;2) DFT calculation of the adsorption energy of main species, thereby obtaining the reaction energy of each elementary reaction; at the same time, the activation energy barrier of each elementary reaction is calculated by DFT;3) constructing a function covering the adsorption energy and / or activation energy barrier;4) in the radical pressure prediction model, first guess the radical pressure, and according to the value of the radical pressure, carry out micro-kinetic simulation including the self-consistent model of coverage degree.The present application combines the characteristics of reaction mechanism, coverage effect and radical pressure in the pore for micro-kinetic simulation; can accurately predict the intrinsic activity of alkane dehydrogenation in zeolite, and realize the agreement of theoretical results and experimental results.

The invention discloses a transition state and catalysis network construction method, which comprises the following steps of: realizing automatic enumeration and screening of reaction intermediates by integrating an element reaction rule base and a graph theory algorithm; intelligent matching and weight optimization of the DFT functional are realized by fusing quantum calculation and machine learning features; by establishing a differentiated transition state search strategy of a multi-complexity scene, high-precision energy barrier calculation from a simple system to a complex system is realized; and dynamic alignment of the catalytic network and real chemical behaviors is realized through path calibration driven by experimental data and an iterative convergence mechanism, and finally, a comprehensive, self-consistent and verifiable catalytic reaction network is constructed.

This invention discloses a comprehensive and detailed reaction mechanism for natural gas / air and its development method. The comprehensive and detailed reaction mechanism includes 290 gas-phase components and 3339 gas-phase elementary reactions, 1 bulk component and 2 surface sites, and 56 soot particle surface reactions. This invention is based on the IDT of chain alkane oxidation, the concentration distribution of small-molecule gas-phase components and large-molecule PAHs of soot nucleation precursors in fuel-rich BSF ethylene flames, the distribution characteristics of soot SVF and PND in fuel-rich BSF and CDF ethylene flames, and the NO content of BSF methane flames under different equivalence ratios. x NO concentration distribution and the reaction of syngas / ammonia in different lean combustion atmospheres x A multidimensional validation study of PK_CNS was conducted, comparing various aspects such as concentration change characteristics. Based on the high consistency between predicted and experimental values, the excellent predictive performance of PK_CNS was verified, and it can be extended to describe the combustion process of natural gas in flame-heated furnaces.

This invention provides a computational method that can analyze the chemical reaction pathways of gases with more complex molecular structures than hydrogen, oxygen, or methane, and for which various elementary reactions are expected, in a relatively short time, and an analytical system that utilizes this analytical method. [Solution] The method for analyzing the chemical change pathway of a gas according to the present invention includes the steps of: inputting information about the gas system; determining a first time period which is the frequency at which collisions between molecules constituting the gas are calculated and the amount of change in the number of molecules is calculated; performing molecular dynamics calculations to calculate the number of molecules based on atomic coordinate data extracted for each of the first time periods; calculating the amount of change in the number of molecules for each of the first time periods by taking the difference in the number of molecules for each of the first time periods; selecting the time period in which the absolute value of the amount of change in the number of molecules is largest; and analyzing the chemical change pathway by extracting atomic coordinate data based on a second time period for the time period in which the absolute value of the amount of change in the number of molecules is largest, wherein the first time period is larger than the second time period.

The invention provides a simulation method of a reversible addition-fragmentation chain transfer (RAFT) polymerization reaction, a storage medium and a computer program.The simulation method comprises the steps that modeling is carried out on the dynamic process of element reactions of all steps of the RAFT polymerization reaction, and based on the occurrence probability of the element reactions in the reaction process, the element reactions of all the steps of the RAFT polymerization reaction are obtained; the change of the molecular number and structure of reactants and products (including intermediate products and final products) along with the reaction time can be obtained, the structure information of more polymer chains can be obtained, and the method can be used for researching the influence of different reactant feeding, reaction temperature and time on the structure and distribution of the RAFT polymerization product. Moreover, in the simulation method of the reversible addition-fragmentation chain transfer polymerization reaction provided by the embodiment of the invention, each monomer unit of a long-chain molecule in the current primitive reaction is represented by an identifier; the identifiers of all the monomer units of the long-chain molecule are stored in the composite linked list structure in the form of nodes according to the molecular structure of the long-chain molecule, that is, the composite linked list structure only stores the identifiers and does not need to store each monomer unit of the long-chain molecule; the efficiency of the simulation method of the reversible addition-fragmentation chain transfer polymerization reaction is greatly improved.

Provided are: a calculation method whereby a chemical change pathway can be analyzed in a relatively short amount of time even for a gas having a more complex molecular structure than hydrogen, oxygen, and methane and for which various elementary reactions are expected to occur; and an analysis system that uses the analysis method. The method for analyzing a chemical change pathway of a gas according to the present invention is characterized by comprising: a step for inputting information about a gas system; a step for calculating the frequency of collisions between molecules constituting the gas and determining a first time slot, which is the frequency at which a change in the number of molecules is calculated; a step for executing a molecular dynamics calculation and calculating the number of molecules on the basis of atomic coordinates data extracted for each of the first time slots; a step for calculating the amount of change in the number of molecules for each of the first time slots by using the difference in the number of molecules in each of the first time slots; a step for selecting the time slot in which the absolute value of the amount of change in the number of molecules is the largest; and a step for analyzing the chemical change pathway by extracting atomic coordinates data on the basis of a second time slot for the time slot in which the absolute value of the amount of change in the number of molecules is the largest, wherein the first time slot is larger than the second time slot.