562 results about "Electric properties" patented technology

The invention belongs to the technical field of dielectric materials, and particularly relates to a dielectric material based on polybenzocyclobutene as well as a preparation method and application of the dielectric material. According to the multi-benzocyclobutene-based dielectric material provided by the invention, different halogenated hydrocarbon, olefin and other raw materials are used, and on the basis of containing more than two benzocyclobutene groups, a specific group can be introduced into a connecting group so as to improve the dielectric property and thermal stability of the material; meanwhile, specific groups can be introduced into R2 and R3 through secondary Heck reaction to further improve the dielectric property and thermal stability of the material, so that the dielectric material with excellent comprehensive properties such as dielectric property and thermal stability is provided, and the technical problem of lack of dielectric materials for high-frequency and high-speed printed circuit boards (PCBs) in the prior art can be solved.

The invention discloses an interface covalently bonded core-shell structure boron nitride polypropylene composite dielectric material and a method. The interface covalently bonded core-shell structure boron nitride polypropylene composite dielectric material comprises a maleic anhydride grafted polypropylene matrix and a core-shell structure filler dispersed in the maleic anhydride grafted polypropylene matrix, the core-shell structure filler comprises hydroxylated boron nitride nanoparticles covalently grafted on a polymer shell layer on the surface of the core-shell structure filler; the polymer shell layer is polyglycidyl methacrylate; the epoxy group of the polymer shell layer reacts with the anhydride group of the maleic anhydride grafted polypropylene matrix to form a covalent bond. The invention has the characteristics of strong interface bonding force, uniform filler dispersion, and excellent comprehensive electrical properties and processability.

An additive manufacturing method based on micro-selective laser melting technology. By using a spot size of 30 μm or less, a metal powder layer thickness of 10 μm or less and ultrafine metal powders having a D90 particle size of 30 μm or less, and in combination with the control of a scanning laser power, a scanning rate, a linear energy density and a volumetric energy density within specific ranges, the method can print complex-structured metal parts having extremely high resolutions and surface smoothness, and can obtain a high-density internal structure of a component even under a relatively low energy density or power condition, thereby effectively protecting an optical system. Moreover, a printed component exhibits a defect-free microstructure, and has excellent electrical properties, thermal properties and mechanical properties. Particularly, ultrafine grains and a high dislocation density provide superior mechanical properties compared to conventional manufacturing materials. An infrared laser device can be used, thereby achieving low costs.

The invention discloses a composite positive electrode, a preparation method thereof and an all-solid-state battery. The composite positive electrode comprises a composite solid electrolyte and a positive electrode active material. The composite solid electrolyte comprises a first solid electrolyte and a second solid electrolyte, wherein the molecular structural formula of the first solid electrolyte is Li < 2 + > (4-a) < x > Zr < 1-x > A < x > Cl < 6-by > By; the second solid electrolyte is selected from one or more of sulfide solid electrolytes; the selection of the metal element A and the non-metal element B meets the condition that XIC * x + (1-x) * 1.687 is less than 1.6; and [(6-by) * 3.16 + y * Xp] / [(6-by + y) * (XIC * x + (1-x) * 1.687)] > = 1.9; wherein the valence state of the metal element A is + a, and the valence state of the non-metal element B is-b; xIC represents the electronegativity of the metal element A, and Xp represents the electronegativity of the non-metal element B. According to the invention, the material forming the composite positive electrode is selected based on the electronegativity of the contained elements, so that the stability and the electrical performance are improved.

The invention relates to the technical field of polypropylene compositions and modified polymer materials thereof, and discloses a high-performance polypropylene-based green energy-saving cable insulation layer composition which comprises an isotactic polypropylene matrix, a maleic anhydride grafted polyolefin elastomer distributed in a dispersed phase and an amide nucleating agent distributed on a non-polar phase interface, an anchoring structure is constructed on a phase interface through hydrogen bond interaction, a matrix molecular chain is induced to grow to form a radial needle-shaped crystal cluster penetrating through the phase interface, and a three-dimensional interpenetrating crystal bridging network is constructed. Through the crystal bridging network, interface deep traps are converted into continuous shallow trap diversion channels, charges are guided to migrate orderly, space charge accumulation is inhibited, and the three-dimensional interpenetrating crystal bridging network is constructed. And the steric effect generated by the interface anchoring structure cooperatively restrains the thermal expansion of the dispersed phase, so that the high-temperature dimensional stability and dielectric property of the material are improved.

The invention discloses a power type negative temperature coefficient thermistor and method for suppressing surge current, and relates to the technical field of negative temperature coefficient thermistors, the thermistor comprises a core body and pins, the pins are respectively arranged on electrodes on two sides of the core body by adopting a multi-contact-surface structure, and the pins are arranged on the two sides of the core body. The core body is made of a Mn-Co-Ni-La oxide with a nano composite gradient structure; the Mn-Co-Ni-La oxide with the nano-composite gradient structure determines the upper limits of core capabilities such as surge suppression, wide temperature stability and low power consumption of the thermistor, and the redesign of the pin is the key of performance transfer, so that the electrical properties (low contact resistance and high surge tolerance) of the Mn-Co-Ni-La oxide with the nano-composite gradient structure are not counteracted by structural defects; the arrangement of the bracket prevents the Mn-Co-Ni-La oxide with the nano-composite gradient structure from losing the effect due to heat accumulation and physical damage through thermal management and mechanical protection, and the three components supplement one another and cooperate with one another, so that the performance of the thermistor of the Mn-Co-Ni-La oxide with the nano-composite gradient structure is guaranteed.

The invention discloses a polyetherimide / polyaryletherketone composite material with high breakdown performance and mechanical toughness as well as a preparation method and application of the polyetherimide / polyaryletherketone composite material, and belongs to the technical field of polyetherimide insulation. The invention solves the problems that the dielectric constant of the polyetherimide can be improved by increasing the use amount of the conductive filler in the prior art, but the breakdown performance of the polyetherimide is reduced, so that the polyetherimide cannot have toughness and high breakdown performance at the same time. According to the invention, polyetherimide and polyaryletherketone are used as raw materials and are mixed by adopting a solution blending method, then a substrate is coated with the mixture, and the polyaryletherketone / polyetherimide / polyaryletherketone composite material is obtained through curing. According to the invention, polyetherimide and polyaryletherketone are well dispersed on a microscopic scale, and the composite material has low dielectric loss of polyetherimide and high toughness of PAEK, and has good dielectric properties and breakdown electrical strength; the material is suitable for the advanced fields of high-energy density capacitors, power electronic devices, aerospace electrical insulation parts, new energy automobile high-voltage systems and the like.

The invention discloses a reverse molecular design method and system of an organic framework material COFs based on a machine learning and quantitative calculation technology, and relates to the technical field of material science and computer simulation. The photoelectric property of the COFs material can be accurately predicted, and a new material can be directionally synthesized under guidance. A COFs structure database is established, Gaussian is used for representing the fragment structure and electronic characteristics of the COFs, a molecular descriptor and a machine learning algorithm are used for establishing a structure-performance mapping relation, quantitative calculation software is used for obtaining an important target quantity for describing the photoelectric characteristics of the COFs, SHAP is used for carrying out importance analysis, and finally a machine learning model for predicting the photoelectric properties of the COFs is obtained. According to the model, through theoretical prediction of a novel COFs structure, a mapping relation between the COFs structure and photoelectric specificity can be established, and a novel COFs hypothetical structure can be reset according to important molecular fragments or word structures of the important molecular fragments; theoretical guidance can be provided for application in the fields of photoelectric catalysts and the like.

The invention discloses a polypropylene composite material with high dielectric constant, high strength and high modulus as well as a preparation method and application thereof, and belongs to the technical field of polymer composite materials. According to the composite material, homo-polypropylene is used as a matrix and matched with a high-dielectric-constant composite filler, a modified reinforcing filler and a functional additive, and through reasonable component design and process optimization, the dielectric property and the mechanical property are synergistically improved. Wherein the barium titanate-graphene with the core-shell structure is used as a high-dielectric-constant composite filler, and an efficient dielectric path can be constructed in a polypropylene matrix; the epoxy resin modified chopped glass fiber can significantly enhance the mechanical strength and modulus of the material; the maleic anhydride grafted polypropylene effectively improves the interfacial compatibility of the filler and the matrix. The dielectric constant (10GHz) of the prepared composite material is greater than or equal to 8, the tensile strength is greater than or equal to 60 MPa, and the bending modulus is greater than or equal to 4000 MPa. The composite material has excellent dielectric properties and mechanical properties, and can be widely applied to the fields of electronic appliances, high-frequency communication, new energy automobiles and the like.

This invention provides a device and method for testing the electromagnetic parameters of thin film materials based on the transmission-reflection method, belonging to the technical field of electromagnetic parameter testing for microwave and millimeter-wave materials. The device uses a rectangular waveguide and a waveguide-coaxial converter as the main structure of the transmission / reflection method testing system, supplemented by supporting and clamping components, thereby enabling the testing of the dielectric properties of lightweight, ultra-thin, and easily deformable thin films and other materials. Simultaneously, based on the structural characteristics of the device, this invention specifically derives an electromagnetic wave reflection model for inverse solving of the dielectric constant of the sample under test.

The invention discloses a friction nano-generator based on silk fibroin composite aerogel, a preparation method and application of the friction nano-generator. Biomass SF serves as a matrix and is combined with high-conductivity MXene, an interface structure between the MXene and the SF is improved through sodium alginate (SA), and biomass conductive aerogel with high mechanical property and electrical property is constructed and serves as a positive friction material; the friction nano-generator, which is combined with a polydimethylsiloxane / barium titanate (PDMS / BaTiO3) composite film with high dielectric property as a negative friction material, has high frictional electricity output property and stability. According to the invention, three different types of friction nano-generators of a plane type, a folding type and a wave type are developed, and the wave type friction nano-generator has the most excellent high-friction electricity output property and stability.

The invention provides an electrical property detection device of an ablation catheter. The electrical property detection device comprises a bearing seat and N conductive probes, the bearing seat is provided with a containing groove which is used for containing the ablation tube section; the N conductive probes are arranged at intervals around the center of the accommodating groove, and the N conductive probes are in one-to-one correspondence with the N electrodes and are in contact conduction with the N electrodes; the conductive probe comprises a rigid conductive part and a flexible conductive part which are stacked in the first direction and connected, the surface, opposite to the rigid conductive part, of the flexible conductive part makes contact with the corresponding electrode, and the first direction is parallel to the extending direction of the center line of the containing groove.

Disclosed in the present invention are a bionic electrothermal coupling composite material based on a pyroelectric effect, a medical kit and a use. The composite material subjected to corona poling treatment of the present invention has a surface potential of about 80 mv, the composite material can generate a pyroelectric effect by loading near-infrared light in vitro, and as can be seen from a diagram showing the variation of pyroelectric current with temperature, charge release occurs during temperature increase, thereby establishing correlation between electrical and thermal properties of a material, and realizing electrothermal effect-driven bionic coupling of the material. The synergistic effect of the piezoelectric properties and the pyroelectric effect is achieved by coupling, achieving the effects of promoting macrophage polarization and promoting tissue repair or healing. In exemplary embodiments, the charge generation capability of a material can be improved by controlling near-infrared light in vitro in a non-invasive manner, on-demand power supply based on a near-infrared light external field is realized, and the problem of insufficient long-term performance of a charged material after implanted into the body is solved.

The invention provides a high-thermal-conductivity flexible epoxy composite material as well as a preparation method and application thereof, and belongs to the field of high polymer materials. The composite material disclosed by the invention is prepared by adding polydopamine modified BN and FG which are jointly used as fillers into an epoxy matrix and adopting polyether amine as a curing agent. The polydopamine modified BN and the FG are jointly used, so that a synergistic interaction effect can be achieved in the aspects of heat-conducting property, dielectric property and mechanical strength. The epoxy composite material disclosed by the invention can obtain excellent heat-conducting property, dielectric property and insulating property under the compatibility of specific raw materials. And when the curing agent with a long molecular chain is adopted, the epoxy composite material can obtain excellent flexibility, and the problem of brittleness of the existing epoxy composite material is solved. A research basis is provided for preparation and performance research of the flexible epoxy composite material, and the flexible epoxy composite material has a good application prospect.

The application relates to the technical field of lightning protection equipment manufacturing, and discloses a composition for preparing a high-stability direct-current resistance sheet, the high-stability direct-current resistance sheet, a preparation method and application thereof. The composition contains the following components: ZnO, Bi2O3, Sb2O3, Co2O3, MnO2, Cr2O3, SiO2, NiO, SnO2, BN, Al(NO3)3.H2O and silver glass powder. The resistance sheet prepared by using the composition has high stability. In addition, the method can avoid resistance sheet grain coarsening, increase the non-uniformity of the internal microstructure and increase the number of pores; the excellent basic electrical performance of the direct-current resistance sheet can be ensured. Meanwhile, the method can make the electrical performance change of the resistance sheet under current impact and the continuous direct-current electric field smaller, and the performance is more stable.

The invention relates to a method for improving a breakdown field strength of polyethylene based on nano-particles grafted with a voltage stabilizer, comprising: 1) dehydration and condensation of nano-particles; 2) carboxyl activation of SDA; 3) grafting with SDA; and 4) preparation of modified nano-composite material. According to the invention, a surface of the nano-particles is modified by an organic group while improving a migration resistance capacity of the voltage stabilizer, and the obtained nano-particles grafted with the voltage stabilizer are doped into a polymer matrix material, so that an electrical property of the matrix material can be improved by both the nano-particles and the voltage stabilizer, and the improvement is stable; and a polyethylene nano-composite material with a significantly improved breakdown field strength can be obtained, thus improving an electrical property of an insulating material, and being beneficial for ensuring the stability of long-term operation of the insulating material.

The invention discloses a state evaluation system of a metal oxide resistor disc for a lightning arrester, relates to the technical field of electrical performance testing, and solves the technical problems that the specific influence degree of environmental factors on insulation resistance is difficult to accurately quantify, and meanwhile, the influence of various factors such as environmental conditions and operation conditions on the performance of the resistor disc cannot be comprehensively considered. By establishing a correlation model, combining the insulation resistance with environmental parameters, fully considering the influence of environmental factors on the insulation performance of the resistor disc, and by establishing the correlation model, the change rule of the insulation resistance can be analyzed more accurately, and reasonable performance change caused by external conditions is considered, so that the insulation performance of the resistor disc is improved. And the performance degradation of the resistor disc can be reflected more objectively in the subsequent comparison with actual detection data. Aging factors are calculated for each region, and the comprehensive health index of the resistor disc in each region is analyzed in combination with the relative deterioration degree coefficient of the insulation resistor, the relative deterioration degree coefficient of the resistive current and the dielectric loss coefficient.

The invention relates to a resin composition, a prepreg, a circuit substrate and a printed circuit board. The resin composition at least comprises: (1) functionalized modified polyphenyl ether resin; (2) hydrocarbon resin, wherein the Vicat softening point of the hydrocarbon resin is 80 DEG C to 240 DEG C; the structural formula of the silicon-nitrogen resin is shown in the formula (1), n is a natural number ranging from 10 to 200, R1, R2, R3, R4 and R5 are independently selected from-H,-OH, amino, C1-C6 alkyl, C1-C6 alkenyl, C6-C12 aryl, C1-C6 alkyl substituted C6-C12 aryl, acrylate or C1-C6 alkyl substituted acrylate, and a molecular chain of the silicon-nitrogen resin at least comprises Si-H groups and Si-vinyl groups. The circuit substrate prepared from the resin composition has high peel strength, high modulus strength, excellent electrical properties and high heat resistance, and has a wide application prospect.

The application discloses a novel flexible printed circuit board and camera module prepared based on weldable low-temperature silver paste, and belongs to the technical field of electronic materials and devices. The conductor pattern in the flexible printed circuit board comprises a main circuit pattern and an auxiliary function structure formed by weldable low-temperature cured silver paste. The curing temperature of the weldable low-temperature silver paste is 87-103 DEG C. The silver paste comprises conductive fillers, a polymer resin system, ester solvents, a curing agent, a silane coupling agent, polyamide wax thixotropic agents, polysiloxane defoaming agents, modified carbon nanotubes, modified antimony tin oxide powder, modified ceramic fillers and low-stress modifiers. The polymer resin system comprises hydrogenated bisphenol A type epoxy resin, diphenyl type epoxy resin and polyacrylate-CTBN copolymer. The conductive fillers comprise silver-coated copper flaky powder, nano silver wire and low-temperature alloy powder. Through the synergistic effect of components and the innovative process, the comprehensive improvement of mechanical properties, conductive properties, high-frequency characteristics and welding reliability is realized under the premise of ultralow-temperature curing.

The application discloses a thermodynamic dual-mode composite sensitive material, a preparation method and application thereof. The composite sensitive material comprises a matrix, has a three-dimensional porous structure, and comprises a polymer material and a sheet-shaped non-metallic conductive material; and metal oxide nanoparticles are distributed on the surface of the sheet-shaped non-metallic conductive material; wherein the sheet-shaped non-metallic conductive material and the metal oxide nanoparticles are both materials with negative thermoelectric coefficients. The thermodynamic dual-mode composite sensitive material provided by the application integrates pressure sensing and thermoelectric performance, which avoids the problems of complex layout and complex signal transmission of a traditional dual-mode sensor; meanwhile, the pressure sensing and the thermoelectric sensing are not interfered with each other, so that the prepared sensor has the advantages of signal non-interference decoupling, avoidance of wear failure, strong adaptability, non-destructiveness, high safety and the like, can adapt to a higher temperature, and has stable temperature signal output.

The invention provides a high-order rectifier wafer for automobile protection and a production process thereof, and relates to the technical field of wafer production. Compared with a traditional technological process, the production process of the rectifier wafer is shortened, the production process can be completed within about 6-8 hours in a high-temperature automatic diffusion furnace in cooperation with a small amount of manpower, and the production efficiency is greatly improved; a glass sintering procedure is omitted, and emission of environmental pollutants such as organic dust is reduced; compared with a 4-5-inch wafer manufactured by an original GPP manufacturing process, the number of crystal grains produced by a single wafer is more, and the cost is greatly reduced; the produced wafer is high in electrical property yield, high in consistency and better in high-temperature reliability, high-temperature resistance and large-current test meet the requirements of high-order automobile accessories, and the application temperature can reach 175 DEG C.

The application discloses a method for preparing a ferroelectric crystal optical superlattice by using a pyroelectric effect, a superlattice and application, and belongs to the field of electronic and optical devices. The method comprises the following steps: preparing a ferroelectric crystal material carrying an electrode pattern; heating the ferroelectric crystal material carrying the electrode pattern, and the heating temperature is 50-200 DEG C; in the temperature range, the ferroelectric crystal material carrying the electrode pattern is excited in the reverse direction of polarization by using the pyroelectric property of the ferroelectric crystal material itself; then, an annealing step is performed, and the annealing rate is 50-150 DEG C / h; after 1-10 times of heating and annealing cycles, the superlattice is obtained. The application breaks through the limitation of the external electric field polarization method for different electrode structures by creating a new polarization process, realizes the preparation of different superlattice crystals based on various structure electrodes, and further expands the application scenarios and application fields of the ferroelectric crystal material.

This invention discloses a high-voltage ceramic capacitor with a reinforced concave structure, aiming to solve the problem of insufficient edge breakdown withstand voltage in traditional ceramic capacitors due to edge effects. The capacitor includes a ceramic core composed of a ceramic dielectric. Its innovation lies in the fact that the upper and lower electrode surfaces of the ceramic core are not planar, but rather form a concave structure that curves inward from the center, causing the ceramic body thickness to gradually increase from the center to the edge. This structure significantly improves the edge breakdown withstand capability through the synergistic effect of electric field homogenization and improved molding density. This invention significantly improves the power frequency withstand voltage of the capacitor to over 3.5kV per millimeter, while also exhibiting excellent comprehensive electrical performance such as low loss, high insulation, and high partial discharge initiation voltage. Furthermore, the manufacturing process is simple, does not increase volume, and has strong industrial applicability.

The application provides a base glass, a preparation method of the base glass, a glass powder, a granulation powder, a glass insulator and a temperature sensor glass sealing workpiece. 3 The base glass comprises BaO 50-80 parts, B2O3 5-30 parts, SrO 1-10 parts, SiO2 1-25 parts, Al2O3 1-15 parts, CaF2 0.1-10 parts, TiO2 0.1-5 parts, rare earth oxide 0.7-3.1 parts and Nb2O5 0.1-3 parts; the rare earth oxide comprises La2O3 and Y2O3. The glass raw material of the application is lead-free, has high strength and air tightness, the lead-free microcrystalline glass system meets the insulation requirement of high-temperature sensors under long-time high-temperature environment, is resistant to repeated temperature impact and will not crack, the electric property does not attenuate, the problem of high-temperature resistance of metal sealing parts is solved, and the performance requirements of high-temperature resistance and high insulation are met.

The invention relates to a method for measuring the thickness of an intermetallic compound of a copper-clad aluminum composite material, and relates to the field of metal material analys.The thickness measuring method comprises the steps that an intermetallic compound sample at the composite interface of a copper-clad aluminum sample is taken, the hardness of the interface is obtained through a nanoindenter, and main constituent compounds of the interface are confirmed through hardness comparison; the method comprises the following steps: cutting a copper-clad aluminum sample to obtain a first sample which contains a composite interface and has a regular shape, testing to obtain the resistance of the first sample, obtaining a first mathematical relationship according to a resistance superposition model, cutting the first sample into a second sample with equal length, and weighing to obtain a second mathematical relationship according to a mass superposition model; and obtaining the thickness of the intermetallic compound according to the two mathematical relationships. According to the method, the characteristic that the electrical property of the intermetallic compound is poor is utilized, the electrical property of the composite material is tested, the electrical property difference between the composite material and pure metal is compared, the proportion of the intermetallic compound is quantitatively given through joint calculation, and the thickness of the intermetallic compound can be rapidly measured.

The application provides an electrochemical device and an electronic device, the electrochemical device comprising a positive electrode sheet, the positive electrode sheet comprising a positive electrode current collector, a first coating layer and a positive electrode material layer, the first coating layer being arranged on the surface of the positive electrode current collector, and the positive electrode material layer being arranged on the surface of the first coating layer away from the positive electrode current collector, the first coating layer comprising a first main material and a first binder, the first main material comprising a solid-state electrolyte, the surface of the solid-state electrolyte being provided with a carbon material, the Dv50 of the first main material being 50 nm to 200 nm, and the thickness of the first coating layer being 0.5 μm to 2 μm. The electrochemical device provided by the application has good nail-penetration safety performance, and also has good cycle performance and low-temperature discharge performance.

Disclosed in the present invention are an unconventional thermoelectric material and a preparation method therefor. The chemical formula of the unconventional thermoelectric material is TiFexRuyCuzSb, wherein x, y and z are respectively the molecule amount of Fe, Ru and Cu in the chemical formula, 1<x+y+z<2, and x and z are not 0. The unconventional thermoelectric material TiFexRuyCuzSb(1<x+y+z<2) provided in the present invention exhibits excellent thermoelectric performance: the Seebeck coefficient thereof exceeds 180 μV / K in a certain temperature range; the figure of merit (zT) can reach 1.2 at 875 K; and the resistivity of TiFexRuyCuzSb exhibits strict linear temperature dependence in the temperature interval of 14 K to 650 K, which breaks through the Mott-Ioffe-Regel (MIR) limit, and exhibits the bad metal transmission properties of non-quasi particles. The unique transmission properties and the high thermoelectric performance benefit from a complicated electronic structure and associated interaction inside TiFexRuyCuzSb, including spin, valence fluctuation, etc., such that TiFexRuyCuzSb can more efficiently convert heat energy into electric energy during the thermoelectric conversion process, thereby improving the energy utilization efficiency.

The utility model discloses a high-efficiency Top-con (Top-con) light component. The top surface of the Top-con battery layer is bonded with a CPC material barrier front plate layer through a second adhesive film layer, the top surface of the CPC material barrier front plate layer is bonded with the composite front plate layer through a first adhesive film layer, and the top surface of the top surface of the Top-con battery layer is bonded with the aluminum-containing metal back plate through a second adhesive film layer. The bottom surface of the Top-con battery layer is bonded with the top surface of the glass fiber reinforced layer through a third adhesive film layer, and the bottom surface of the glass fiber reinforced layer is bonded with the aluminum-containing metal backboard through a fourth adhesive film layer. The advantages are that the multi-layer structure design obviously improves the flexibility and impact resistance of the assembly, and the assembly can adapt to complex curved surfaces and special installation environments; through scientific matching of multiple layers of materials, the problems that a traditional packaging material is prone to water vapor permeation, adhesive film degradation, grid line corrosion and the like are solved, the packaging reliability of the Top-con light assembly is comprehensively improved, and it is ensured that the assembly has excellent electrical property stability and use safety in long-term operation.

This invention relates to a method for assessing the defect risk of epoxy-impregnated paper bushing cores under rapid temperature rise conditions, belonging to the field of bushing core insulation condition assessment. This invention aims to solve the problem that existing technologies cannot assess the impact of bushing core defects on partial discharge and dielectric properties under rapid temperature rise scenarios. The technical solution includes: constructing a feature parameter dataset and determining defect classification thresholds; conducting performance parameter tests before and after rapid temperature rise; comparing and analyzing the defect discharge characteristic spectrum of the bushing core, the sensitivity of partial discharge under different voltage measurement methods, and the changes in high-voltage broadband dielectric spectrum characteristic parameters under cyclic voltage excitation; and finally achieving defect risk classification assessment. This invention can comprehensively assess the electrical performance reliability of bushing cores, effectively identify potential defect risks within the core, and provide technical support for the safe and stable operation of ultra-high voltage transmission systems under extreme temperature environments.

The invention discloses a flexible copper-clad plate with high thermal conductivity and low dielectric property and a preparation method of the flexible copper-clad plate. The flexible copper-clad plate comprises an insulating substrate, the composite film is a thermoplastic polyimide / heat-conducting low-dielectric ePTFE / thermoplastic polyimide insulating composite film which is composed of a middle layer ceramic / boron nitride-expanded polytetrafluoroethylene functional hybrid membrane and thermoplastic polyimide layers on the two sides of the middle layer ceramic / boron nitride-expanded polytetrafluoroethylene functional hybrid membrane. And the flexible conductive metal foil is compounded with the single surface, double surfaces or multiple layers of the insulating substrate through a thermal forming compounding process. Through the mode, the flexible copper-clad plate can have excellent peel strength under the adhesive-free condition through structure optimization and process innovation, low dielectric constant and low dielectric loss tangent value can be realized under the high-frequency condition, and meanwhile, the heat conductivity coefficient is remarkably improved. And through continuous production, the efficiency is greatly improved, and a high-reliability base material is provided for the high-end electronic fields such as new energy vehicles, 5G / 6G communication and wearable equipment.