266 results about "Isotropy" patented technology

The invention belongs to the technical field of computer vision and three-dimensional point cloud processing. The invention provides an anisotropic point cloud convolution method based on local geometric self-adaption. According to the embodiment of the invention, the principal component analysis is carried out on the neighborhood point cloud to estimate the principal direction of the local geometric structure, and the affine transformation matrix is constructed; and performing dynamic deformation on the basic kernel point of the convolution operator by using the matrix, so that the shape and the direction of the convolution kernel are dynamically aligned with the local structure of the point cloud. The convolution operator is integrated into a point cloud registration network, and can be used for feature extraction of three-dimensional point clouds, especially underwater multi-beam depth finder point clouds. The convolution operator constructed by the method can effectively capture the structure priori of the strong anisotropic point cloud, and solves the problems of structure information loss and limited feature extraction capability caused by the isotropic kernel processing the data.

The invention relates to the technical field of industrial visual inspection, in particular to a 3D (three-dimensional) gluing glue type defect detection method based on three-dimensional measurement, which comprises the following steps: firstly, acquiring a point cloud by using three-dimensional measurement equipment, carrying out manifold pretreatment, constructing a substrate plane by fitting substrate data, and separating the point cloud of a glue strip based on the plane; secondly, extracting a geometric skeleton, searching a physical extreme point by using an isotropic spherical neighborhood, and decoupling the dependency of feature extraction and a slice direction; calculating a path differential attribute and an offset vector relative to a substrate plane, constructing a dimensionless centrifugal deformation index, and correcting a geometric tangent vector according to the dimensionless centrifugal deformation index to generate an anisotropic slice normal vector; and finally, obtaining a dynamic section based on the corrected normal vector, and quantifying defects by utilizing curvature mutation characteristics. According to the method, the geometric frame is corrected by constructing the dimensionless physical field, so that the section projection error caused by centrifugal force and gravity is effectively eliminated, and the detection precision of complex track 3D coating is remarkably improved.

The disclosure concerns a 3D printhead, a radiation emission device, and processes for additive fabrication and extrusion. The printhead comprises a radiating plate configured to transmit a thermal energy to the printing material deposited on a surface. A radiation emission device may be attached to an additive fabrication or extrusion device and comprising a radiating plate and a heating element. Additive fabrication and extrusion processes using a radiation for heating a surface for deposition of the material. Characteristics of products thus produced, such as porosity rate, warping, isotropy, maximum stress, internal stress, impact resistance, bending resistance, deformation at break, rigidity modulus, crystallinity rate, and impermeability are improved.

The invention relates to an aperiodic disturbance control vibration grid turbulence generation device, which comprises a vibration grid device and a flow field observation device, and is characterized in that the vibration grid device comprises a water tank frame, a water tank, a linear slide rail, a linear module, a vibration grid, a motor and a control system PLC module; the flow field observation device comprises an optical platform, an auxiliary LED lamp and a particle image velocity measurement system, wherein the particle image velocity measurement system comprises a high-speed camera, a laser and a computer. According to the invention, isotropic turbulence in a complex mode can be simulated, and the application range of equipment is expanded. According to the invention, the limitation of a vibration grating device based on periodic disturbance control is overcome, and a more flexible experiment platform is provided for turbulence mechanism research and application of the turbulence mechanism in the fields of material transportation, diffusion, sedimentation, flocculation and the like.

The invention discloses a preparation method of a high-aspect-ratio glass through hole and the glass through hole. The preparation method comprises the following steps: forming a photoresist mask on the surface of a substrate; performing a first etching step, performing isotropic first etching on the substrate by using plasma of a first gas from which charged particles are filtered, and forming a first polymer layer on the inner wall of the formed through hole and the photoresist mask for protection; performing a second etching step, performing anisotropic second etching on the first polymer layer on the bottom of the inner wall by using plasma of a second gas, exposing the substrate below, and performing the first etching again; after the first etching step for a first preset number of times is completed every time, performing a treatment process on the formed through hole; and repeatedly executing the first etching step, the second etching step and the treatment process until the through hole is formed in the substrate. The process can be simplified, the selection ratio can be improved, the efficiency can be improved, and better side wall smoothness can be realized.

The invention relates to the technical field of machining part non-ideal surface generation, and particularly discloses a wavelet and fractal-considered assembly junction surface construction method which comprises the following steps: S1, according to an ideal mathematical model of an assembly junction surface, S2, comparing calculation methods of different fractal parameters, S3, aiming at the part assembly junction surface in different machining modes, calculating fractal fractal parameters according to a calculation method of the different fractal parameters; s4, the assembly junction surface is regarded as a structure formed by superposition of contours of different scales, S5, a power spectrum analysis method is introduced to analyze the surface contour curve characteristics of the assembly junction surface, and S6, according to the isotropic or anisotropic properties of the surface of the assembly junction surface in different machining modes, the surface contour curve characteristics of the assembly junction surface are analyzed. The statistical distribution characteristic parameters determined in the step S3 are introduced into characterization of the assembly joint surface; and S7, the contour curve characteristic parameters extracted in the step S4 are associated with the fractal parameters determined in the step S2. According to the method, multi-scale decomposition is carried out on the assembly joint surface through wavelet transform, and the specificity information of the roughness contour, the waviness contour and the shape error contour can be effectively extracted.

The application relates to the technical field of non-ideal surface generation of machined parts, and particularly discloses a construction method of an assembly joint surface considering wavelet and fractals, which comprises the following steps: S1, according to an ideal numerical model of the assembly joint surface; S2, comparing calculation methods of different fractal parameters; S3, aiming at the assembly joint surface of parts under different machining modes; S4, regarding the assembly joint surface as a structure formed by superposition of different scale contours; S5, introducing a power spectrum analysis method to analyze the surface contour curve characteristics of the assembly joint surface; S6, according to the isotropic or anisotropic properties of the assembly joint surface under different machining modes, introducing the statistical distribution characteristic parameters determined in step S3 into the representation of the assembly joint surface; and S7, associating the contour curve characteristic parameters extracted in step S4 with the fractal parameters determined in step S2. Through multi-scale decomposition of the assembly joint surface by wavelet transform, the specific information of the roughness contour, the waviness contour and the shape error contour can be effectively extracted.

The invention relates to the technical field of heat-insulating and demagnetizing refrigeration, and discloses a heat-insulating and demagnetizing refrigeration material based on a Trellis crystal lattice and a preparation method and application of the heat-insulating and demagnetizing refrigeration material. The chemical formula of the heat insulation and demagnetization refrigeration material based on the Trellis crystal lattice is Gd2GeB2O8. A magnetic test result of the Gd2GeB2O8 crystal shows that the magnetic anisotropy of the crystal material is relatively weak and tends to magnetic isotropy, and a long-range magnetic orderliness phenomenon is not observed above 1.8 K. And when adiabatic demagnetization is carried out under initial conditions that T is equal to 3K and B is equal to 7T, the material can reach the maximum negative magnetic entropy difference of 51.68 J * kg <-1 > * K <-1 >, which shows that the Gd2GeB2O8 has a better application prospect in a 3-17K temperature zone and a sub-Kelvin temperature zone.

The application provides a kind of multi-modal feature fusion-based harsh environment image enhancement and restoration method, belongs to image enhancement processing field;The method first obtains multi-modal image and calculates each modal degradation degree graph;Based on the degradation degree and gradient amplitude, a fusion weight is constructed, and the local dominant direction and coherence are obtained by structure tensor analysis;According to the coherence, the pixels are partitioned, and the adaptive processing of each modal gradient is carried out by using hard projection, isotropic fusion or soft projection strategy respectively;Based on the fusion weight, the processed gradient is weighted and fused, and the fusion gradient field is obtained combined with the enhancement factor g (x) ;Finally, an energy function containing pixel fidelity term and gradient fidelity term is constructed, and the enhanced fusion image is reconstructed by weighted least squares optimization;The application suppresses the contribution of blurred modal through degradation perception mechanism, and solves the gradient direction conflict through structure adaptive projection, which significantly improves the clarity and structure fidelity of multi-modal image fusion in harsh environment.

The invention discloses a face key point detection network training method, a face key point detection method and a medium, and belongs to the technical field of face key point detection, and the method comprises the steps: obtaining a face image data set; in the face image data set, each sample is a face image marked with key point coordinates; for each sample in the face image data set, key points in the sample are divided into boundary endpoints and boundary internal points, and coordinates of the key points are converted to a heat map coordinate system; under the heat map coordinate system, generating a true value heat map for each boundary endpoint by adopting isotropic Gaussian distribution, generating a true value heat map for each boundary internal point by adopting anisotropic Gaussian distribution, and forming a training data set by the face image and the true value heat map of each key point in the face image; and training a face key point detection network used for predicting a heat map of each key point in the face image by using the training data set to obtain a trained face key point detection network. According to the invention, the detection precision of the face key points can be effectively improved.

A method for classifying a subterranean formation includes rotating an ultrasonic logging tool in a borehole penetrating a formation. The ultrasonic logging tool includes an ultrasonic transducer and an array of spaced apart ultrasonic receivers deployed on a logging tool body. The ultrasonic logging tool measures an azimuthal shear slowness image and an azimuthal compressional slowness image while rotating in the borehole. The images are evaluated to classify the homogeneity / heterogeneity and isotropy / anisotropy of the formation.

This invention relates to a method for testing the fracture toughness of anisotropic eccentrically loaded single-sided notched tensile specimens, comprising: S1, establishing a two-dimensional plane stress model of anisotropic material ESET specimens; S2, mesh generation; S3, calculating displacement, strain, and stress field to obtain the stress intensity factor K and compliance C under different initial crack lengths and anisotropic material parameters; S4, establishing crack length calculation formulas and stress intensity factor calculation formulas based on compliance under different eccentric loading rates, initial crack lengths, and anisotropic material parameters. This invention allows for rapid and accurate measurement of crack length simply by measuring the deformation of the material under external force; it reliably extends the application range of standardized eccentrically loaded single-sided notched tensile specimens from traditional isotropic metals to modern advanced materials such as composite materials, additive manufacturing alloys, and rolled plates, while ensuring the calculation accuracy under anisotropic conditions.

The present application belongs to the technical field of large metal forging, and particularly relates to a multi-direction orthogonal forging method for improving the isotropy of the performance of forgings. The method comprises the following steps: selecting a steel ingot, setting the axial direction of the steel ingot as the Z direction, setting a radial direction as the Y direction, and setting another three-dimensional direction perpendicular to the Z direction and the Y direction as the X direction; upsetting the selected steel ingot along the Z direction, and then elongating it along the Y direction; upsetting the obtained blank along the Y direction, and then elongating it along the X direction; upsetting the obtained blank along the X direction, and then elongating it along the Z direction; and cutting off the excess material of the obtained blank, thereby obtaining the final product. The X, Y and Z directions are sequentially and positively crossed to be upset and elongated once each time, and the elongation direction is finally changed back to the direction of the initial upsetting of the steel ingot. The deformation amount of the steel ingot accumulated in each of the three directions after forging is basically the same, and the isotropy of the performance of the forgings is greatly improved.

The invention discloses a scatterer-based one-way coupling topology photon cavity with variable perimeter. The device comprises a shielding case, and an electrospinning continuous medium layer and an air layer which have a chiral surface state at the junction of the shielding case and the electrospinning continuous medium layer; a cylindrical rotary electric continuous medium is also distributed in the air layer, and a first scatterer of an isotropic medium exists between the cylindrical rotary electric continuous medium and an interface where the chiral surface state is located; and air exists at the junction of the first scatterer and the cylindrical rotating electric continuous medium and the chiral surface state. The one-way coupling topological photon cavity with the variable perimeter gets rid of dependence on strict periodic conditions, and can realize a one-way coupling effect under the condition of photon cavities with different perimeters. While the scattering suppression transmission characteristic of the chiral boundary state is realized, the unidirectional coupling between the chiral boundary state and the scatterer is closely related to the direction of an external magnetic field in the rotary electric continuous medium. Furthermore, by changing the radius size and the magnetic field direction of the photon cavity, the one-way coupling topology photon cavity with variable perimeter and controllable coupling direction is realized.

The application provides a preparation method of an isotropic Ti2AlNb / TiAl-based interpenetrating composite material and belongs to the technical field of intermetallic compound-based composite materials. First, a plurality of Ti2AlNb reinforcing body skeletons in a TPMS configuration are designed by using a hidden function modeling; then, anisotropy of the TPMS configuration is studied by using finite element simulation; secondly, the Ti2AlNb reinforcing body skeleton in the TPMS configuration is prepared by using a selective laser melting process SLM; finally, the Ti2AlNb / TiAl-based interpenetrating composite material in the TPMS configuration is prepared by vacuum hot pressing sintering HPS. Thus, the strong anisotropy of a traditional fiber reinforced composite material in mechanical properties is avoided, good matching of the strength, plasticity and toughness of the composite material is realized, and a new idea and solution are provided for breaking through the application bottleneck of a TiAl in a thermal end part of a space power system.

The invention relates to the technical field of optical micro-control, in particular to a multi-particle optical control and sorting method and device. The invention aims to solve the problem of difficulty in optical control of a multi-particle system. The optical control and sorting method comprises the following steps: constructing a tripolymer particle system consisting of three isotropic micro-nano particles in a uniform liquid medium, wherein the tripolymer particle system is completely immersed in the liquid medium and has a symmetry axis vertical to the surface of the liquid medium; the method comprises the steps that a linear polarization Gaussian beam passes through a polarization adjusting module, a shaping and beam expanding module and an incident angle adjusting module according to a preset sequence, and enters a trimer particle system from the position above the surface of a liquid medium according to a preset mode; by adjusting the polarization adjusting module and the incident angle adjusting module, the motion direction and the motion speed of the tripolymer particle system are optically controlled. The device comprises a sample table, a laser emitting module and an optical control assembly.

The invention discloses a three-dimensional failure criterion construction method considering bedding and three-dimensional stress and intermediate principal stress effect degradation, and the method comprises the steps: S1, obtaining rock strength data through true triaxial static tests under different bedding dip angles, direction angles and intermediate principal stress; s2, constructing a transverse isotropic strength characteristic function based on the spatial relationship between the bedding structure and the loading direction; s3, introducing an intermediate principal stress degradation parameter, and establishing a rock failure criterion considering three-dimensional stress and intermediate principal stress effect degradation; s4, constructing a three-dimensional failure criterion considering bedding space and three-dimensional stress and intermediate principal stress effect degradation; s5, determining model parameters by fitting static test data, and drawing a strength evolution curve; and S6, based on the three-dimensional failure criterion parameters, drawing a stratified rock strength prediction curve. According to the method, quantitative characterization of true three-dimensional stress, middle principal stress degradation and bedding three-dimensional space effect coupling of the strength of the layered rock is achieved for the first time.

The invention provides an urban building deformation monitoring leak detection point identification method and system, and belongs to the technical field of urban building health monitoring. According to the method, the isotropic hypothesis of a traditional two-dimensional plane buffer area is abandoned, a parameterized three-dimensional confidence space conforming to an SAR side-looking imaging physical mechanism is additionally constructed on the basis of contour strong judgment, multiple factors such as the radar sight line direction, the incident angle, the building height and the shielding effect are fully considered, misjudgment of non-target scattering points is effectively avoided, and the detection accuracy is improved. The spatial affiliation relationship between the PS point and the building is more accurate, and the reliability of omission ratio evaluation is remarkably improved.

The invention discloses a photoelectric sensor system conversion efficiency calibration system and method based on a reverberation chamber, and belongs to the technical field of photoelectric sensor conversion efficiency calibration, the system comprises an electric wave reverberation chamber, a transmitting antenna, a reference antenna and a photoelectric field sensor system; the photoelectric field sensor system is composed of a photoelectric sensor, a laser source, a photoelectric detector, a polarization maintaining optical fiber and a single-mode optical fiber. In the calibration process, the reference antenna and the photoelectric sensor system are used as receiving ends respectively, receiving power at different stirring positions in the reverberation chamber is sampled to obtain two groups of transfer functions, and the total efficiency of the photoelectric sensor system is determined by comparing the two groups of transfer functions under the condition that the radiation efficiency of the reference antenna is known. The conversion efficiency of the photoelectric sensor system is obtained by combining the relation among the power, the field intensity and the total efficiency in the free space; and the effective averaging of the incident direction and the polarization state is realized by using the uniform and isotropic electromagnetic field characteristics of the reverberation chamber.

A three-dimensional isotropic metamaterial is formed by gathering a plurality of metamaterial atoms having a three-dimensional structure with a minimum thickness of 1 μm or more in a transparent resin.

The present invention features a liquid, solvent-free, silica precursor and two-photon 3D printing process to meet the increasing needs of high-precision glass micro-optics and address the major limitations of current three-dimensional (3D) printing optics. The printed optical elements may be fully converted to transparent inorganic glass at temperatures as low as 600° C. with shrinkages as low as 17%. The present invention includes a complete process chain, from material development, printing process, and performance evaluation of the printed glass micro-optics. 3D printing of glass micro-optics with isotropic shrinkage, micrometer resolution, low deviation peak-to-valley value (<100 nm), and low surface roughness (<6 nm) has been demonstrated. The present invention enables the rapid fabrication of complex glass micro-optics previously impossible using conventional glass optics fabrication processes.

Methods and apparatus are disclosed for concurrent digital autoradiography of alpha-particle events and positron events using a spatially resolving charged particle detector and a gamma-ray detector. Alpha particles and positrons are detected by the charged particle detector. Positrons are identified based on coincidence with gamma-ray events. A positron-emission autoradiograph is formed based on positron positions. Alpha particles, both coincident and anticoincident with positrons, are identified based on energy deposition patterns. An alpha-emission autoradiograph is formed based on alpha-particle positions and energies. Separation of coincident alpha and positron events recorded by the charged particle detector improves position detection accuracy. Validation of positron imaging for alpha-emitter distribution or dosage, based on correlation of respective autoradiographs, is described. Variations for particle identification based on isotropy, energy, coincidence, or anticoincidence are presented. Disclosed techniques are applicable to alpha-emitting radionuclides with complex decay chains.

The invention provides an inclined plane four-beam lattice light sheet super-resolution microscopic imaging device and method based on spatial spectrum estimation. The device is composed of an input light beam, a cylindrical lens group, an SLM, a reflector, a lambda / 4 wave plate, a PBS, a mask, a relay lens group, a galvanometer, an objective lens, a camera and other optical elements. By utilizing four-beam interference formed by the SLM and a high-reflectivity mirror surface on the opposite side of a sample, a lattice light sheet illumination field is realized, and fluorescence excitation is finely regulated and controlled; the same objective lens with a high numerical aperture and a three-stage infinite correction microscopic system are utilized to realize fluorescence excitation and collection, the loading space limitation of a traditional light sheet microscope is broken through, and distortion caused by high axial magnification and aberration is avoided; in combination with a spatial spectrum estimation algorithm, a measurement matrix is constructed for a low-resolution image sequence, eigenvalue decomposition is carried out, an optimal signal-to-noise ratio threshold is adaptively determined, signal and noise subspaces are divided according to the threshold, spectrum peak search is carried out by using subspace orthogonality, and thus isotropic resolution improvement is realized.

A selective acoustic electromagnetic transducer (400) for a Lamb wave propagation mode of interest propagating in a structure, comprising a circularly shaped magnet (401) and a coil (402) comprising several independent concentric circular portions and a processing unit (403) connected to the ends of each circular portion, the processing unit (403) being configured to generate a composite signal equal to a linear combination of the signals measured on each circular portion, the coefficients of the linear combination being chosen so as to minimize the sensitivity of the coil (402) to a set of Lamb modes excluding the mode of interest. Figure 4a

Methods, systems, and devices are disclosed for optimizing a radiation pattern of an indoor ceiling and / or wall mounted radio unit for a distributed antenna system / radio point system (DAS / RDS). According to one aspect, a method includes obtaining beamforming weights for generating a shaped radiation pattern that provides a same effective isotropic radiated power (EIPR) at a plurality of locations within a target cell; and applying the obtained beamforming weights to a signal directed to an array of antenna elements of a radio interface to generate the shaped radiation pattern.

The application provides a closed composite structure substrate applied to a space camera, and the optical substrate comprises a central high-stability area, a force-bearing cylinder and a carbon fiber frame plate which are sequentially arranged from inside to outside, and an envelope area of the optical substrate is covered with a skin to form a closed shell structure substrate; the central high-stability area comprises a metal matrix composite central cylinder, and an outer annular surface of the central cylinder is provided with a metal matrix composite main support framework, an auxiliary support framework and a carbon fiber auxiliary support framework; the central high-stability area and the carbon fiber frame plate are both internally filled with isotropic hexagonal flange carbon honeycombs. The central high-stability area composed of the metal matrix composite, the frame plate with the carbon fiber material structure and the honeycomb layout design can guarantee high rigidity and high stability of the substrate, and the weight reduction advantage is remarkable, and the material cost is reduced; the inlay layout of the special-shaped heat pipe, the support structure and the force-bearing cylinder optimizes the size and the precision stability of the whole substrate.

The invention belongs to the technical field of image processing, and particularly discloses an image restoration method and device based on deep learning and electronic equipment, and the method comprises the steps: obtaining a training data set which comprises an isotropic low-quality image and a directional high-quality image in pairs; training a neural network model based on the data set to enable the neural network model to learn a feature mapping relation from an isotropic low-quality image to a directional high-quality image; obtaining an isotropic low-quality image of a to-be-detected sample, and performing geometric transformation on the isotropic low-quality image to enable a to-be-restored target direction to be aligned with a high-quality direction obtained by the model; inputting the transformed image into a model to obtain a predicted image, and restoring the high-quality direction to a target direction through inverse geometric transformation; and finally, fusing the original directional high-quality image of the to-be-detected sample with the recovered target direction high-quality image.

The invention discloses a composite magnetorheological fluid capable of providing a stable and wide second Newtonian region, which comprises anisotropic magnetic powder, the content of which is 0.05-5% of the total weight of the composite magnetorheological fluid; micron-scale isotropic magnetic powder, the content of which is in the range of 70-90% of the total weight of the composite magnetorheological fluid; the carrier liquid and the additive are added into the carrier liquid, and the content of the additive is the balance of the composite magnetorheological fluid.

The invention provides a tunnel surrounding rock brittleness-ductility transformation critical confining pressure prediction method and device under a complex crustal stress field, and relates to the technical field of rock mechanics analysis. The method comprises the following steps: by introducing parameters representing rock strength anisotropy, correcting a Mohr-Coulomb strength criterion, and constructing a strength prediction model; dividing stress areas according to the ground stress level, and establishing a corresponding joint surface friction strength model for each divided stress area in combination with joint surface stress state analysis; converting the rock strength from anisotropy to isotropy as a critical condition of brittle-ductile conversion, and combining the strength prediction model with the joint surface friction strength model of the corresponding stress area to obtain a critical confining pressure theoretical model; in the critical confining pressure theoretical model, the static internal friction angle is replaced with a rock instantaneous internal friction angle changing along with the confining pressure, and a critical confining pressure prediction model is obtained; and inputting the mechanical parameters of the surrounding rock of the target tunnel into the critical confining pressure prediction model, and calculating to obtain a critical confining pressure value.

This invention discloses a method for designing a thermostat in a porous medium thermal convection environment based on phase change materials. The thermostat employs a double-layer structure. Under the background of uniform flow and linear temperature change, three concentric circles are set in the middle of the background region, with the small circle forming the central region. The inner annular region, outer annular region, and background region are all covered with isotropic porous media. The inner annular region is the functional region, which uses a phase change material with asymmetric thermal conductivity and permeability. The changes in thermal conductivity and permeability with temperature satisfy the temperature trapping condition to maintain a constant temperature in the central region. The ratio of thermal conductivity and permeability of the media between the outer annular region and the background region is governed by the same geometric relationship, satisfying the dual stealth conditions of thermal field and flow field. This invention provides a new thermal control scheme for porous medium systems, microfluidic systems, and other fields.