7 results about "Bond length" patented technology

The invention relates to the technical field of thermodynamic properties of alloy materials, in particular to a method for calculating vibration free energy based on a bond length-bond stiffness relationship, which comprises the following steps: selecting configurations with the same symmetry according to chemical bond information contained in a crystal structure, uniform stretching or compression deformation is applied to the key body so as to generate key lengths with different lengths; supercells are created for configurations with different key lengths, micro disturbance is applied to atoms with different symmetry in the supercells, and force is calculated; obtaining a force constant matrix between two adjacent atoms according to a force calculation result, and diagonalizing the force constant matrix to obtain tensile bond rigidity and bending bond rigidity; and fitting a key length-key stiffness function according to the tensile key stiffness and the bending key stiffness corresponding to different key lengths to obtain a force constant matrix of all possible key lengths so as to calculate vibration free energy. According to the method, the calculation cost is effectively reduced under the condition that the calculation precision is guaranteed, and a solution is provided for accurately predicting the alloy phase diagram and guiding alloy design.

The present invention provides a method, a system and a device for calculating the bond length and bond angle of hydrogen bonds at different frequencies. The method includes the following steps: calculating the coordinates of each atom in the unit cell at the maximum displacement and the equilibrium position during vibration at each frequency; calculating the bond length and bond angle of the hydrogen bond at the maximum displacement and the equilibrium position of the atom during vibration at each frequency based on the frequency and the coordinates; and judging based on the change amount between the bond length and bond angle of the hydrogen bond at the maximum displacement of the atom at each frequency and the bond length and bond angle of the hydrogen bond at the equilibrium position. The method, the system and the device for calculating the bond length and bond angle of hydrogen bonds at different frequencies according to the present invention are used to evaluate the response of hydrogen bonds to different frequencies. If the change amount is large, the response is intense; if the change amount is small, the response is gentle.

The invention relates to the field of surface and interface mechanical properties of composite materials and coatings, and discloses a method for evaluating interface bonding strength based on first principles. The method comprises the following steps: step 1, obtaining the structure of each material, establishing a surface model of each material, and establishing an initial interface model; step 2, performing a vacuum layer thickness test, a layer number convergence test, and an interface distance test on the initial interface model to obtain an interface test model; step 3, using a first principles calculation method to relax the surface model and the interface test model structure, calculate the surface energy of the surface, calculate the interface energy and adhesion work of the interface test model, analyze the change of the electronic structure during interface bonding through state density and differential charge density results, and evaluate the interface bonding strength of each material; step 4, performing simulated stretching on the interface test model to obtain the ultimate stress and strain of each material, and calculate the change of the differential charge density, population value and bond length of each material during the strain process.

This invention provides a rapid screening method for medium- and high-entropy rare-earth disilicate materials of ytterbium disilicate. The method includes selecting rare-earth elements that can form a monoclinic β phase after equimolar doping of Yb₂Si₂O₇ materials as dopants, obtaining the average RE-O bond length; classifying dopants according to whether they increase or decrease the average bond length, and sorting them by doping weight; establishing a periodic table of orthogonally increasing doping elements based on the sorting results, where materials in the same period or group have the same increasing doping element relative to materials in the previous period or group; conducting material preparation and thermodynamic property experiments; summarizing the experimental results into the periodic table to form a thermodynamic property periodic table, and selecting the most suitable material or the element to be doped. This method can rapidly screen multi-component doped medium- or high-entropy materials, and based on the thermodynamic property periodic table, it can also determine the magnitude of the performance benefits of various dopants on medium- or high-entropy materials.

The present invention discloses a micro-potential peridynamics method for structural deformation analysis, and the method comprises the following steps: establishing a solid model and determining corresponding material properties; discretizing the structure into a series of material points in a spatial domain; using a second-order deformation measure of bond length change to measure the deformation of the material points; adopting a micro-bond potential energy function between the discretized material points of the structure; introducing the micro-bond potential energy function between the material points, and integrating the obtained micro-bond potential energy function within the near-field range of the material points to obtain the non-local elastic strain energy density of the material points; deriving a bond force model between the material points through the variation of the non-local elastic strain energy density; setting calculation initial conditions and applying force or displacement boundary conditions; submitting static and dynamic calculations; and performing strain analysis based on the deformation results. By introducing the micro-bond potential energy function of the material points, the present invention derives a brand-new bond force model of the material points. The bond force model does not contain any unknowns, does not require simplifying the model to check and calibrate the bond parameters, and simplifies the steps.

This invention relates to the field of spectroscopic analysis technology, specifically to a method for molecular vibration and hydrogen bond network analysis. This method involves acquiring terahertz absorption spectra of samples at different temperatures; acquiring Raman scattering spectra of samples; constructing a unit cell model of the target peptide and calculating its theoretical vibrational spectrum; obtaining the evolution of frequency offset parameters and full width at half maximum (FWHM) parameters with temperature, and performing mathematical fitting; comparing the terahertz absorption and Raman scattering spectra with the theoretical vibrational spectrum to identify the molecular vibrational modes corresponding to each characteristic absorption and scattering peak; performing mode decomposition on the calculated multiple infrared active vibrational modes to quantitatively distinguish the contribution ratios of intermolecular translation, intermolecular rotation, and intramolecular vibration in each vibrational mode; and analyzing the relative changes in bond length and bond angle of intermolecular hydrogen bonds within the target peptide unit cell. This invention systematically analyzes the vibrational behavior of peptide molecules, especially KLVFF peptides.

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.