11 results about "Electrical anisotropy" patented technology

The invention discloses a device and a method for measuring stress in a forming process of a large-size aviation transparent part, and relates to the technical field of polymer injection molding measurement. The device comprises a flexible substrate matched with the surface of a mold cavity, and an interdigital electrode array, a dielectric anisotropy measurement module and a polymer stress calculation module which are arranged on the flexible substrate, the interdigital electrode array is arranged in a non-uniform distribution mode, a high-density arrangement area is arranged in a stress sensitive area, and a sparse array arrangement area is arranged in a non-sensitive area; the module is used for detecting dielectric constants and calculating principal stress differences of different positions. The flexible substrate is utilized to adapt to a complex curved surface, through the non-uniform array design, global coverage of a large-size workpiece is guaranteed, meanwhile, high-resolution capture of a key area is achieved, signal crosstalk caused by global high-density arrangement is effectively avoided, and accurate, lossless and real-time measurement of the forming stress of the large-size aviation transparent part is achieved.

The application discloses a grating type gate voltage structure-based electrical anisotropy device and a preparation method thereof. A grating type gate voltage electrode structure is arranged on a heterojunction to establish a size-in-situ adjustable electric potential field, form an artificial stripe phase electron channel, and realize in-situ regulation and control of horizontal resistance and vertical resistance of a lower two-dimensional electron gas. Great positive magnetoresistance and negative magnetoresistance effects are realized in two mutually perpendicular directions, and great electrical anisotropy is regulated and controlled. The grating type gate voltage electrode structure is grown on a cross-shaped semiconductor heterojunction, great planar electrical anisotropy in different current directions under a magnetic field can be realized, the size of electrical anisotropy of the device can be in-situ regulated and controlled by changing the size of the gate voltage, and in addition, the method has the advantages of simple micro-processing technology, good universality, large-area batch production and the like.

The application discloses a screening method and device of piezoelectric anisotropic perovskite material, and high-throughput calculation and screening are performed on tetragonal phase ABO3 perovskite oxide material through first principle calculation, the correlation between piezoelectricity and lattice tetragonality, polarization displacement, spontaneous polarization and elastic constant is pointed out, and the method can be used for screening and guiding design of high-performance piezoelectric material. The application gives a three-dimensional representation of piezoelectric coefficient, re-evaluates the piezoelectric coefficient ratio |d 33 / d 31 | which is widely used at present, and points out the deficiency in representing piezoelectric anisotropy, and can be extended to anisotropy of other piezoelectric materials.

The present application provides a method for producing a transparent conductive film having small electrically conductive anisotropy even if containing metal nanowires. The method for producing a transparent conductive film of the present application includes: a coating step of forming a coating layer by coating a composition for forming a transparent conductive layer containing metal nanowires on a long substrate while transporting the substrate; and a drying step of drying the coating layer to form a transparent conductive layer on the substrate, the average inclination angle θa of the surface of the substrate being 0.5° or more.

The present application relates to the technical field of advanced inorganic non-metallic material preparation, and particularly relates to a wet compounding preparation process of graphene modified conductive thermoplastic polyurethane. The present application provides a solution to the problems in the prior art, such as easy agglomeration of graphene filler, mechanical performance decline caused by increased filler addition, insufficient anisotropic regulation of thermal / electric conductivity, large amount of organic solvent, high recovery cost, and complex process difficult to be continuous; graphene oxide and TPU emulsion are dispersed, oriented and arranged in a low-boiling azeotropic solvent through microfluidic laminar shear; then, a vertical ice crystal template is constructed by using directional-bidirectional freezing technology, and the freeze-dried material is selectively photothermally reduced by using 808nm laser pulses, polydopamine is introduced on the surface of GO, and silver nanowires are filled in the interlayer gap of graphene sheets to realize a multi-scale conductive network. Finally, the performance of the composite material is improved and the process is optimized.

This invention relates to a 2D / 3D heterojunction layer, its fabrication method, and a large-area direct-type perovskite wafer X-ray detector, belonging to the field of perovskite radiation detection technology. A 2D / 3D heterojunction is constructed by combining bismuth iodide (BiI3) with perovskite. BiI3 serves as the heterolayer on the perovskite light-absorbing layer, and is then used in a large-area direct-type perovskite wafer X-ray detector. Under dynamic pressure, the two-dimensional planes of BiI3 gradually become perpendicular to the direction of the applied force, resulting in a uniform orientation, i.e., a single-crystal orientation. This leads to electrical anisotropy in the layer, providing a barrier to ion migration. Simultaneously, the formation of a heterostructure that matches energy levels facilitates charge separation and collection, thereby improving X-ray detection performance.

This invention discloses a carbon material, its preparation method, and its applications, belonging to the field of anode material technology. The carbon material includes: a carbon substrate and a reinforcing carbon layer covering at least a portion of the surface of the carbon substrate; the reinforcing carbon layer is composed of at least two stacked carbon coating layers with different lattice orientations, with adjacent carbon coating layers having different lattice orientations. In this invention, the preferred lattice orientations of adjacent carbon coating layers are different, causing cracks to deflect, branch, or stop propagating at the interlayer interface, significantly improving the fracture toughness of the carbon layer; this multi-orientation stacked structure can uniformly disperse the anisotropic stress generated by silicon volume expansion into interlayer shear strain, avoiding local stress concentration; simultaneously, the three-dimensional conductive network constructed by multi-orientation microcrystals overcomes the defects of single-orientation coating layers in terms of conductive anisotropy and insufficient rate performance, ultimately providing stronger and more uniform physical constraints for repeated silicon expansion.

The invention discloses a complex reservoir rock core electrical property evaluation method and system based on an orthotropic electrical theory, and relates to the technical field of oil and gas reservoir exploration theories and application, and the method comprises the following steps: constructing a complex reservoir rock core orthotropic electrical basic model, and determining the orthotropic expression form of conductivity and resistivity tensor; according to the method, an electrical theoretical model based on orthotropic conductivity tensor is constructed, a tensor expression form containing transverse conductivity and longitudinal conductivity is established, a corresponding resistivity tensor is derived, and the electrical resistivity of the current transformer is calculated through a Maxwell equation set and a generalized Laplacian equation. A control equation of a stable current field in the anisotropic medium is established, systematic description of the conduction rule of the current in the orthotropic medium is achieved, the limitation that a traditional method depends on isotropic hypothesis is overcome from the theoretical root, and a rigorous mathematical physical foundation is laid for accurate characterization of the electrical anisotropy of a complex reservoir core.

The application provides a skin medium radio frequency characteristic data processing method and system. The method comprises: collecting and processing radio frequency electric signals of a target area to construct a complex dielectric space-time feature set; inputting the complex dielectric space-time feature set into a pulse neural network, dynamically adjusting the membrane potential leakage rate of LIF neurons in the pulse neural network by using the medium charge polarization relaxation time constant calculated by complex impedance to perform space feature extraction based on physical polarization relaxation, and obtaining a space feature vector; inputting the complex dielectric space-time feature set into a Transformer module, constraining and calibrating the self-attention mechanism by using the physical attenuation factor of electromagnetic waves in the medium, and obtaining a time sequence feature vector; dynamically weighting and fusing the space feature vector and the time sequence feature vector to generate a fusion feature matrix, inputting the fusion feature matrix into a classifier, and outputting electrical anisotropy classification feature spectrum line data of the target area. The system comprises a signal acquisition module, a signal preprocessing module and a fusion model module.

The invention discloses a device and method for measuring stress distribution in the thickness direction of a transparent part, and belongs to the technical field of polymer stress measurement, and the device comprises an interdigital electrode array unit which comprises a flexible substrate and a plurality of interdigital electrodes which are arranged on the flexible substrate and have different detection depths; the dielectric anisotropy measurement module is used for driving an electrode to detect complex dielectric constants of polymers in different detection depth ranges; and the stress distribution calculation module in the polymer thickness direction is used for calculating an average principal stress difference according to the complex dielectric constant and obtaining a layering principal stress difference in the polymer thickness direction by using an integral reverse algorithm. The flexible substrate is utilized to adapt to the surface of a complex mold, the electrode arrays with different depths are matched with a reverse algorithm, lossless, real-time and accurate measurement of the layering stress in the thickness direction of the polymer is achieved, and the anti-interference capability is high.

This invention relates to a dimetacrystalline compound, its preparation method, and its applications. The liquid crystal composition formed by the dimetacrystalline compound provided by this invention has suitable optical anisotropy, dielectric anisotropy, clearing point, and flow viscosity, and can be applied to liquid crystal display devices. Furthermore, the synthesis route of this dimetacrystalline compound is short, the yield is high, the post-processing is simple, and the cost is low, making it suitable for industrial production.