14 results about "Crystal base" patented technology

The invention discloses a two-dimensional acoustic crystal based on a microstructure. A functional material layer of the two-dimensional acoustic crystal comprises square acoustic cells which are periodically arranged in an xy plane according to a square lattice; a scatterer in the acoustic cell has rotational symmetry and is composed of a cross structure and four identical semicircles, the cross structure is composed of two identical rectangular strips in an orthogonal mode, the diameter of the semicircle is collinear with the short edge of the rectangular strip at the tail end where the semicircle is located, and the diameter of the semicircle is larger than the length of the short edge of the rectangular strip. The rotation angle of the scatterer is matched with the geometric parameter of the scatterer, so that the physical energy band structure of the two-dimensional acoustic crystal generates a triple degeneracy point formed by the first three physical energy bands at the M point of the Brillouin region, and further a stable boundary state with global characteristics is realized. Furthermore, an acoustic frequency beam splitter is constructed on the basis of the boundary state, and sound waves of different frequency bands are split to form included angles of 180 degrees and 90 degrees.

The invention discloses a macrosegregation prediction simulation method for directional solidification of a large ingot. The method specifically comprises the following steps: (1) obtaining thermophysical parameters of a material; (2) establishing a three-dimensional model of directional solidification and large cast ingots and carrying out grid division; (3) calculating mass, momentum, energy and solute transfer required by solidification of the metal material through a four-phase coupling model, wherein four phases comprise a liquid phase, an equiaxed crystal phase, a columnar crystal phase and a gas phase; (4) setting boundary conditions; (5) dynamically judging the growth areas of the isometric crystal and the columnar crystal based on the temperature gradient and the supercooling degree threshold value, wherein the columnar crystal only starts to grow from the casting mold wall and tracks the tip position of the columnar crystal; (6) iteratively solving the conservation equation of each phase until convergence, and outputting a liquid phase fraction, grain distribution and a solute concentration field; and (7) verifying by adopting an actually produced cast ingot, and quantifying the macrosegregation degree through a segregation index (SI).

The invention belongs to the field of laser damage resistance evaluation methods, and relates to a method for evaluating laser damage characteristics of a crystal based on photo-thermal weak absorption. The method for evaluating the laser damage characteristic of the crystal based on the weak photo-thermal absorption comprises the following steps: firstly, carrying out nondestructive testing on the weak photo-thermal absorption on a to-be-detected crystal to obtain a weak absorption rate; and evaluating the laser damage resistance of the to-be-tested crystal according to an Exponential-Chapman function relationship by using the obtained weak absorptivity. The Exponential-Chapman function relationship is as follows: F = a (1-e-b alpha) c, a, b and c are all fitting coefficients, alpha is the weak absorption rate, and F is the energy density.

Embodiments of the present application provide a crystal calibration method, device and computer equipment, the method. The method comprises obtaining a cycle count value of a target crystal in a preset time interval, the cycle count value being the vibration frequency of a reference crystal in the time interval; if the cycle count value is not in a preset count value reference interval, calibrating the target crystal until a calibration stop condition is reached. The method provided by the present application can calibrate the frequency of the target crystal based on the reference crystal, improve the reliability of the target crystal, increase the application range of the internal low-speed crystal, thereby reducing the circuit board area and component cost.

The application discloses a method for measuring color center density in a BBO crystal, comprising the following steps: building a measurement system containing the measured BBO crystal; calculating the total loss of the optical system corresponding to different input pump powers of the measurement system at different temperatures based on the optical characteristic parameters of the optical system in the measurement system; and calculating the color center density of the measured BBO crystal corresponding to different pump powers at different temperatures according to the total loss and the optical characteristic parameters of the optical system. The application calculates the color center density of the BBO crystal based on the optical characteristic parameters and the total loss of the measurement system by constructing a simple measurement system, and the measurement equipment and method are simple and fast, the measurement cost is greatly reduced, and the influence factors are less, so that a good foundation is provided for the accuracy of the measurement result.

A crystal growth control method, apparatus, system, and storage medium are disclosed. The method includes: acquiring crystal growth data of a previous crystal sequence; determining a diameter deviation weight for each crystal based on a set diameter at a predetermined length position and the actual diameter within a predetermined time period, and performing a weighted sum based on the actual heating power of each crystal at the predetermined length position and its diameter deviation weight to obtain a first heating power; determining a pulling speed deviation weight for each crystal based on a set pulling speed at a predetermined length position and the actual pulling speed within a predetermined time period, and performing a weighted sum based on the actual heating power of each crystal at the predetermined length position and its pulling speed deviation weight to obtain a second heating power; and performing a weighted sum of the first heating power and the second heating power to obtain a target heating power for the next crystal at a predetermined length position, thereby controlling the growth process of the next crystal. This application reduces the incidence of intrinsic defects within the crystal and improves the crystal yield.

The application relates to a crystal growth control method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring growth change data of a crystal in a specified growth stage and a visual diameter of the crystal, wherein the visual diameter is acquired based on an image acquisition device; determining a theoretical diameter of the crystal based on the growth change data and a growth control parameter of the crystal in the specified growth stage; correcting the visual diameter based on a first deviation corresponding to the theoretical diameter and the visual diameter to obtain a target diameter of the crystal; and adjusting the growth control parameter based on the target diameter to control the growth of the crystal based on the adjusted growth control parameter. Therefore, the stability of the diameter of the crystal in the constant-diameter growth stage can be effectively improved through accurate diameter control.

The invention discloses a method and a measuring system for solving birefringence phenomenon double-light tracks of a uniaxial crystal, and the method comprises the steps: defining a front surface normal vector, a rear surface normal vector and an optical axis direction vector of the crystal, and representing the spatial orientation of the crystal through the rotation operation around an x axis and a y axis; calculating a normal vector and an optical axis direction vector after rotation according to the rotation angle of the crystal around the z axis; based on the refraction law, the Snell law and the Fresnel equation, the propagation directions of the o light and the e light in the crystal are deduced; considering the refraction behavior of the rear surface of the crystal, and respectively calculating direction vectors after the o light and the e light are emitted; and determining the coordinates of the o light and the e light on the observation screen by utilizing a point equation and combining a ray tracing method, and rotating the crystal for one circle to generate a dual-light trajectory. According to the method, any crystal rotation operation is processed through a unified coordinate system, and the calculation complexity of a complex scene is reduced; the systematic intersection solution algorithm provided by the invention is combined with the e light wave vector / light separation calculation model, so that the light spot positioning efficiency is improved.

The invention discloses a crystal preparation method. The method comprises the following steps: acquiring a first wafer subjected to first treatment; taking the first wafer subjected to the first treatment as a first seed crystal, and growing based on a top seed crystal solution growth method to obtain a prefabricated crystal; performing second treatment on the prefabricated crystal; and taking the prefabricated crystal subjected to the second treatment as a second seed crystal, and growing based on a physical vapor transport method to obtain a target crystal.

The invention provides a LiInSe2 medium-wave infrared photoelectric material optimization method and device and a target doped structure crystal, the method comprises the following steps: determining a plurality of doping positions in a LiInSe2 crystal based on a rule of crystal symmetry and spatial distribution uniformity of doped elements, each doping position comprising the position of a part of In atoms in the LiInSe2 crystal; metal atoms with valence electron structures similar to In atoms are doped into the LiInSe2 crystal according to the multiple doping positions so as to replace part of In atoms in the LiInSe2 crystal, and multiple doped structure crystals are obtained; and determining a plurality of target doped structure crystals based on the plurality of doped structure crystals by adopting a first principle and a multi-layer screening mode, and taking the plurality of target doped structure crystals as the optimized medium-wave infrared photoelectric material. According to the invention, fine regulation and control of an energy band structure and photoelectric response can be realized, the stability of the medium-wave infrared photoelectric material is improved, and the absorption performance of medium-wave infrared light is remarkably enhanced.

The invention relates to the technical field of bicrystal substrates, and particularly discloses a preparation method of a strontium lanthanum tantalum aluminate bicrystal seed crystal, which comprises the following steps: preparing a first strontium lanthanum tantalum aluminate bicrystal crystal base material by using a sintering method, cutting a crystal blank with an intact crystal boundary from the first strontium lanthanum tantalum aluminate bicrystal crystal base material, and carrying out rough polishing, chemical polishing and ion beam polishing to obtain a first bicrystal seed crystal; preparing a large-size or small-size second strontium lanthanum tantalate aluminate bicrystal crystal base material from the first bicrystal seed crystal by using a pulling method, and cutting a crystal blank from the second strontium lanthanum tantalate aluminate bicrystal crystal base material to obtain the strontium lanthanum tantalate aluminate bicrystal seed crystal. The preparation method comprises the following steps: preparing a first strontium lanthanum tantalate aluminate bicrystal crystal base material by using a sintering method, cutting a crystal blank with an intact crystal boundary from the first strontium lanthanum tantalate aluminate bicrystal crystal base material by using diamond wire cutting to serve as a first bicrystal seed crystal, preparing a large-size strontium lanthanum tantalate aluminate bicrystal crystal by using a pulling method, and cutting the crystal blank from the large-size strontium lanthanum tantalate aluminate bicrystal crystal to serve as a seed crystal of a subsequent growth crystal; the crystal boundary of the grown bicrystal crystal is naturally closed, and the bicrystal crystal is free of voids, defects and external dust particle pollution and is compact and uniform in structure.

The application discloses a method for fine modification of the interior of a crystal based on double-beam laser focus interference, and belongs to the field of laser precision machining. The method is realized by adjusting the divergence angle of double beams by using a laser shaping device to realize the overlap of focus A and focus B. The double foci overlap and interfere, and the interference phenomenon of the energy intensity alternately changing occurs in the focus overlap area; under the interference, laser energy is concentrated to the interference enhancement position, and the energy peak value can exceed the modification threshold of the material interior, and modification occurs; the size of the double-focus overlap area is compressed relative to the conventional single-focus area, and the modification by interference only occupies a part of the overlap area, and the size of the modification area is further compressed. Compared with the conventional single-focus modification area, the longitudinal size of the modification by the method can be compressed by at least 50%, and the precision of the micro-nano structure in the processed crystal is higher. According to the characteristics of the crystal material, laser parameters are selected, and scanning is carried out according to a preset track, modification points form a modification line, and then high-precision machining of a complex micro-nano structure in the crystal can be realized.

The invention discloses an optical property prediction method of a fluoride laser crystal based on deep learning, which belongs to the technical field of deep learning and material science and comprises the following steps: constructing a source domain data set of the fluoride crystal with a crystal stability label, and training a source domain model by taking structural parameters and a chemical formula of the fluoride crystal as input to obtain a source domain model; obtaining a crystal stability prediction model; the constructed optical property prediction model comprises a feature extractor and a detection head which are connected in sequence, and the feature extractor is a structure branch GNN and a component branch CoTAN in the crystal stability prediction model; the detection head is used for mapping the features extracted by the feature extractor into a prediction result of the optical properties of the crystal; and inputting the obtained structure parameters and the chemical formula of the fluoride laser crystal to be predicted into the optical property prediction model to obtain an optical property prediction result. According to the method, the crystal stability prediction model is introduced into the optical property prediction process through transfer learning, the problem of scarcity of crystal optical data is solved, and the model prediction precision is improved.

The present invention discloses an electron microscopic image crystal structure intelligent analysis system and method, which includes a data import module for importing electron microscopic images and crystal structure data; an image preprocessing module for preprocessing the imported electron microscopic images to obtain an experimental spectrum; a diffraction simulation module for simulating two-dimensional electron diffraction of a crystal based on the imported crystal structure data to obtain a diffraction simulation result, and processing the diffraction simulation result to obtain a theoretical spectrum; an intelligent matching module for matching the experimental spectrum with the theoretical spectrum and outputting the matching result; and a result output module for outputting the matching result and the diffraction simulation result to realize crystal structure visualization. Under the synergistic effect of each module, the electron microscopic image crystal structure can be automatically analyzed in the entire process, greatly improving the efficiency of crystal structure analysis; and under the action of the intelligent matching module, rapid matching can be achieved and the error rate can be reduced.