5 results about "Primitive cell" patented technology

The application belongs to the technical field of multiferroic materials, and relates to a design method of a multiferroic material based on a vanadium-doped two-dimensional ferroelectric body and the multiferroic material. Single-layer NbOI2 primitive cells are expanded in different directions to obtain supercells of different sizes. Vanadium is used as a doping element to dope the supercells of different sizes, and the doping configurations of each supercell under different doping concentrations are obtained. The doping configuration with the lowest total energy of the ferromagnetic state and the antiferromagnetic state under each doping concentration is used as the ground state configuration of the doping concentration. The band gap Eg and the spontaneous ferroelectric polarization intensity along the b-axis of the ground state configuration under different doping concentrations are calculated. A double-Y-axis curve graph is drawn with the doping concentration as the horizontal coordinate and the spontaneous ferroelectric polarization intensity and the band gap Eg as the vertical coordinate, and the multiferroic phase region and the magnetic semimetal phase region are divided. The doping concentration-physical property evolution phase diagram is obtained, so that the corresponding doping concentration value range of the ground state configuration with the multiferroic phase of ferroelectricity and antiferromagnetism is obtained to design the multiferroic material.

A technique generates a hierarchical three-dimensional structure or volume mesh and uses intelligent compaction using a Barycenter compact model. Any primitive cells or blocks can be represented physically by a Barycenter compact model (or Barycenter model), and any black box model can also be physically represented by a Barycenter compact model physically. A boundary condition between blocks is formulated by the Barycenter compact model. Boundary condition problems between blocks can be limited within two levels only if using the Barycenter compact model. A technique generates a hierarchical three-dimensional volume mesh and uses intelligent compaction using a Barycenter compact model.

This application relates to the field of acoustics, and in particular to a method for realizing a three-dimensional phononic crystal structure, an acoustic supercell, and an acoustic device. The phononic crystal structure is composed of multiple stacked unit cells; each unit cell includes several resonant cavities and acoustic coupling channels connecting the resonant cavities; the layers are connected by interlayer acoustic coupling channels; the geometric parameters of the resonant cavities and acoustic coupling channels are configured to satisfy a tightly bound model with chiral symmetry, such that the phononic crystal structure forms nodal loops in three-dimensional momentum space and supports higher-order topological hinge states at the rigid boundary edges of the phononic crystal structure. This invention can achieve stable higher-order topological hinge states while maintaining the characteristics of nodal loops, and has the advantages of simple structure and ease of fabrication.