3063 results about "Electromagnetic shielding" patented technology

The invention provides a multi-mode large model-based precision metal part defect detection method and system. The method comprises the following steps of: acquiring laser scattering image data of a precision metal part in an electromagnetic shielding environment; performing multi-scale spatial analysis on the laser scattering image data to extract a multi-modal image feature set containing a crystal boundary topological structure of the surface of the precision metal part and scattering spot distribution gradient features of the subsurface; converting process parameters, corresponding to the precision metal part, in an existing metal heat treatment process database into heat historical feature vectors, wherein the heat historical feature vectors comprise temperature gradient distribution features and time sequence phase change features; performing fusion processing on the thermal historical feature vector and the multi-modal image feature set through a multi-modal large model to obtain a fusion processing result so as to generate defect detection data; according to the invention, the detection rate and the detection efficiency of micron-sized defects in a complex electromagnetic environment are improved.

The invention provides a weak signal multi-module networking self-adaptive monitoring system for power transmission and transformation construction, and relates to the technical field of multi-module networking, and the system comprises a multi-mode module which is used for deploying a multi-mode sensing unit at a key monitoring point of power transmission and transformation equipment, collecting vibration, partial discharge, leakage current and environmental parameter signals, and transmitting the signals to a monitoring center; the signals are processed through packaging of an electromagnetic shielding shell and a built-in harmonic filter circuit so as to obtain original monitoring signal data; and the detection module is used for inputting the original monitoring signal data into the chaotic enhanced weak signal detection device, and extracting a fault feature vector by capturing an attractor phase diagram abrupt change and a time domain waveform threshold. Through the multi-mode sensing and self-adaptive networking technology, monitoring of power transmission and transformation weak signals and timely extraction of fault features are achieved, and the fault early warning accuracy and the self-adaptive capacity are improved.

The invention relates to a deep integrated electric drive assembly design method and system, and the method comprises the steps: obtaining the parametric modeling data of an electric drive assembly, and carrying out the digital twin synchronous motor modeling, and obtaining a drive three-dimensional model; topological structure data of the electric drive assembly are obtained, and mixed algorithm optimization calculation is carried out on the topological structure data and the drive three-dimensional model to obtain a system optimization solution set; performing model prediction control construction based on the system optimization solution set, and performing gear contour line modification processing on the electric drive assembly to obtain a speed reduction transmission strategy; performing heat dissipation management extraction optimization on the system optimization solution set according to a preset variable cross-section micro-channel heat dissipation algorithm to obtain a dynamic heat dissipation strategy; preliminarily integrating the speed reduction transmission strategy and the dynamic heat dissipation strategy to obtain an initial design scheme; eMI filtering optimization is carried out on the initial design scheme, multi-stage electromagnetic shielding construction is carried out, and a system performance optimization scheme is obtained. The comprehensive performance of the system can be improved through integral design, regulation and control.

The invention discloses an online multi-channel rapid gas chromatographic analysis system and method, particularly relates to the technical field of gas chromatographic analysis, and is used for solving the problems of baseline noise rise and trace component detection precision reduction caused by physical coupling and signal interference when multiple detectors work in parallel in the prior art. Interference signal features of adjacent detection channels are extracted, a chaotic or linear compensation signal is dynamically generated in combination with harmonic primary and secondary sorting and recursive quantization factor analysis, and common-mode interference of a target channel is suppressed. Electromagnetic isolation parameters of a shielding structure are adjusted in real time based on the baseline signal after noise suppression, and accurate matching of impedance and interference spectrum is achieved; further separating time domain overlapped signals and analyzing asymmetric distortion characteristics, and eliminating system errors through normalization calibration; dynamic interference suppression, electromagnetic shielding optimization and signal distortion traceability are combined, the anti-interference capability and analysis precision of multi-channel detection are remarkably improved, and the method is suitable for high-throughput rapid detection scenes of complex samples.

An integrated carbon honeycomb structure material and its preparation method are disclosed, belonging to the field of carbon materials technology. Based on a co-sacrificial template low-temperature pyrolysis strategy, the target material can be obtained through three main steps: preparation of a metal salt-colloidal microsphere template precursor, precursor pressing and molding, and subsequent calcination and carbonization. This technology has the characteristics and advantages of simple preparation process, regular and controllable macroscopic structure of the sample (such as shape, area, and thickness), rich and tunable chemical composition, and three-dimensional interconnection of graphene carbon matrix. It has great application potential in many fields such as electrochemical energy storage, catalysis, gas separation, adsorption, and electromagnetic shielding.

The invention relates to the technical field of power transmission line anomaly recognition, and particularly discloses a power transmission line anomaly recognition model construction method combined with edge calculation, which comprises the following steps of: gradually increasing electromagnetic interference intensity test, acquiring current and voltage signals in real time, and monitoring electric field intensity and signal change by combining a high-precision sensor; dynamically calculating an influence value of electromagnetic interference; recursively estimating the dynamic influence of the electromagnetic interference through a Kalman filter, accurately modeling the influence of the electromagnetic interference by combining the system state and measurement data updating, and realizing the real-time evaluation of the influence of the interference on the system by calculating an electromagnetic interference coefficient and an electromagnetic shielding efficiency expected deviation; according to the method, a spectral analysis and high-frequency current and voltage fluctuation feature extraction method is adopted, and accidental interference and system faults are effectively distinguished by calculating a spectral ratio; through multi-level data analysis and optimization, real fault signals and electromagnetic interference signals can be accurately distinguished, and false alarms and missing alarms are reduced.

The invention relates to an electromagnetic shielding method and shielding system for power distribution, and belongs to the technical field of electromagnetic shielding. Comprising the following steps: establishing a shielding model corresponding to the shielded room according to volume data of the shielded room; simulating and positioning electromagnetic wave conditions in the shielded room in the shielding model; selecting key detection points; constructing a phase difference matrix; shielding requirements of different waveforms in the same frequency band are distinguished, leakage path positioning based on a waveguide equation is carried out, and a core leakage area and an auxiliary protection area are divided. According to the electromagnetic shielding method and shielding system for power distribution provided by the invention, the dynamic adaptability of electromagnetic shielding and the detection capability of transient electromagnetic pulses are remarkably improved, and a multi-dimensional risk quantification and differentiation reinforcement strategy is realized. Meanwhile, intelligent materials and a dynamic optimization mechanism are adopted, the material utilization rate and the protection effect are improved, and a reinforcing effect feedback closed loop is formed.

The invention relates to the technical field of wireless communication, in particular to a wide-stop-band filtering coupler based on a rectangular coaxial structure, which comprises a rectangular coaxial outer conductor upper cavity, an inner conductor circuit and a rectangular coaxial outer conductor lower cavity, and is characterized in that the inner conductor circuit is arranged between the rectangular coaxial outer conductor upper cavity and the rectangular coaxial outer conductor lower cavity through a medium supporting block; the inner conductor circuit comprises an input port, a straight-through port, a coupling port, an isolation port and a branch line coupler structure. Four ports of the branch line coupler structure are respectively in coupling connection with the input port, the straight-through port, the coupling port and the isolation port through a quarter-wavelength open-circuit parallel coupling line structure. The novel rectangular coaxial transmission line is adopted for design, so that the circuit has the advantages of the rectangular coaxial metal transmission line, the electromagnetic shielding structure enables the circuit not to be easily interfered by external electromagnetic wave signals, and the rectangular coaxial transmission line can control the impedance requirement by changing the proportion of the inner conductor and the outer conductor according to different design requirements.

The invention relates to the field of super-hydrophobic materials, in particular to a basalt fiber composite material as well as a preparation method and application thereof. According to the composite fabric material provided by the invention, a multistage micro-nano rough surface of the MoS2 nanoflowers and the silver nanoparticles is constructed on the fiber substrate, so that not only is super-hydrophobic self-cleaning realized, but also the anti-icing performance is relatively high, and particularly, rapid heating is realized by combining broadband absorption of the MoS2 nanoflowers and a local surface plasma resonance effect of the silver nanoparticles; and meanwhile, the silver nanoparticles accelerate heat conduction, so that excellent ice melting capability is obtained. The high conductivity of the silver nanoparticles constructs a conductive path, and the layered structure of MoS2 triggers interface polarization, so that the electromagnetic shielding effectiveness of the X wave band is improved. The dual antibacterial mechanism of the MoS2 nanoflowers and the silver nanoparticles also realizes broad-spectrum efficient antibiosis, the preparation method is green and environment-friendly, the cost is low, and the requirements of complex scenes such as wearable electronic equipment, medical protection, polar region protection and national defense can be met.

The invention belongs to the technical field of composite material design, and discloses a polyimide-based composite material design method and system based on experiment-machine learning collaborative optimization. The method comprises the following steps: S1, experimental database construction and machine learning performance modeling; S2, machine learning model construction and training; S3, model evaluation and performance index output; and S4, intelligent design of the polyimide-based composite material. The multi-objective performance collaborative optimization design and preparation of the polyimide-based ternary carbon heterostructure composite material are carried out by taking experimental data as a main material and machine learning as an auxiliary material. According to the method, an experiment-model-optimization closed-loop iterative design system is constructed based on an experiment-machine learning collaborative optimization method, the method has the advantages of high prediction precision, high optimization efficiency, good multi-target adaptability and the like, the development efficiency of the polyimide-based composite material is remarkably improved, and the development cost of the polyimide-based composite material is reduced. The method is suitable for intelligent design and large-scale application and popularization of the high-performance heat-conducting electromagnetic shielding material.

The invention discloses a multi-parameter ultrahigh frequency sensor performance comprehensive evaluation method, which belongs to the technical field of sensor performance evaluation, and effectively breaks through the limitation of the traditional static test on a transient interference response blind area through a dynamic interference field simulation test and an original fidelity-false triggering joint evaluation model. The adaptive adjustment mechanism of the multi-source interference field can vividly simulate the space-time non-uniform characteristic of electromagnetic noise in an industrial field, and in combination with a time-frequency domain composite evaluation algorithm, not only is the signal distortion degree of the sensor in typical interference modes such as frequency sweeping and pulse train quantified, but also the error action acceleration rule caused by high-frequency-band noise coupling is disclosed. The dynamic immunity evaluation capability enables a designer to accurately position the electromagnetic shielding weakness of the sensor, optimizes a front-end filter circuit or a signal processing algorithm in a targeted manner, and remarkably improves the reliability of a product in strong interference scenes such as radar detection and wireless communication.

The invention provides an integrated circuit chip electromagnetic interference intelligent suppression and shielding method and system, and relates to the technical field of integrated circuits, and the method comprises the steps: collecting chip electromagnetic interference data, and carrying out the time-frequency domain decomposition and feature extraction, so as to obtain an initial electromagnetic interference feature vector; calculating an electromagnetic interference threat index based on state space mapping and action space search, and further evaluating the electromagnetic interference situation and determining the minimum shielding strength; carrying out optimization design on the electromagnetic shielding structure by adopting a gradient-guided genetic algorithm to obtain an optimal shielding structure parameter; real-time electromagnetic interference data are adjusted according to the parameters, the suppression ratio is calculated, and iterative design is carried out by combining the suppression ratio optimization genetic algorithm. According to the invention, intelligent evaluation and dynamic suppression of electromagnetic interference are realized, and the accuracy and adaptability of shielding structure design are improved.

The invention discloses a perception and communication detection platform and method in a complex weak communication environment. According to the detection platform, a high-simulation multi-physical field coupling test environment is constructed by integrating a weak illumination perception mechanism and capability test module, an anti-interference communication mechanism and capability test module, a complex environment detection mechanism and capability test module, a data acquisition and analysis system, a multi-scene coupling controller and a full-experiment-area weak electromagnetic shielding case. The adaptive test efficiency of the unmanned system in weak illumination, strong interference and complex terrain environments is remarkably improved, the method can be widely applied to the fields of underground exploration, emergency rescue and intelligent inspection, and the field test cost and risk are reduced.

The invention provides an unmanned aerial vehicle navigation signal interference method and system based on an electromagnetic shielding array. According to the method, firstly, a navigation signal sent by a target unmanned aerial vehicle is monitored, positioning information transmission characteristics in the navigation signal are identified, then a periodic dynamic interference mode synchronous with a navigation signal transmission period is generated according to the positioning information transmission characteristics, and then, through spatial gradient barrier distribution of an electromagnetic shielding array, a dynamic interference mode is generated. Converting the periodic dynamic interference mode into directional space interference energy, and finally controlling the directional space interference energy to be continuously applied to a navigation signal receiving path of the unmanned aerial vehicle so as to complete navigation signal interference of the unmanned aerial vehicle. According to the technical scheme provided by the invention, a frequency hopping anti-interference mechanism of the unmanned aerial vehicle is effectively cracked, invalid energy consumption is remarkably reduced, the interference efficiency is improved, and error interference on non-target equipment is avoided.

The invention discloses a multi-channel high-precision water level dynamic real-time monitoring system for a drilling water pumping test, and the system comprises a sensing layer which is used for deploying a multi-source sensor array, inhibiting interference through distributed layout and electromagnetic shielding, collecting multi-dimensional data in real time, and carrying out the preliminary filtering; according to the transmission layer, an optical fiber and twisted pair redundant network is constructed, an EtherCAT protocol is adopted for low-delay transmission, AES-128 encryption tampering prevention is integrated, and edge nodes compress data and verify integrity; the processing layer is used for carrying out real-time preprocessing on edge calculation and switching a standby sensor in abnormal detection; the cloud end predicts the water level trend through Spark Streaming analysis and an LSTM model, distinguishes interference through a random forest algorithm, and outputs calibration data and an analysis report; the application layer is used for constructing a three-dimensional drilling model based on Unity, dynamically displaying water level changes, synchronizing a multi-parameter curve and supporting historical backtracking; the early warning module notifies abnormity through sound and light and short messages, the decision module generates a report and supports multi-drill-hole comparison, and the test strategy is optimized.

The invention provides an intelligent coating method and system for a paint-free suite door. The method comprises the following steps: continuously scanning the surface of a door body through a multi-band optical detection device to obtain reflection intensity data of visible light and near-infrared bands, and synchronously collecting environment temperature and coating temperature data of a coating area; activating the composite electromagnetic shielding structure to absorb external interference, and transmitting the purified multi-source data through a star topology network; carrying out denoising processing on the reflection intensity based on a dynamic modeling algorithm, and carrying out dynamic calibration on the coating thickness model in combination with the real-time temperature parameters to generate a three-dimensional thickness distribution thermodynamic diagram; and the high-degree-of-freedom mechanical arm is driven to execute space trajectory compensation motion, and finally stress balance control in the coating curing process is achieved. According to the technical scheme provided by the invention, accurate control over the coating thickness uniformity and active inhibition of thermal stress in the coating process of the paint-free suite door are achieved, and the coating quality and the process stability are remarkably improved.

The invention discloses a multi-scene wireless network rapid deployment method based on an electromagnetic field digital twinning technology, and relates to the technical field of computer application, and the method comprises the following steps: S1, constructing a three-dimensional digital twinning model of a corresponding scene, and integrating a building structure, equipment layout and material attribute data, and establishing a scene special material database containing metal equipment, a concrete wall body and an electromagnetic shielding layer. According to the multi-scene wireless network rapid deployment method provided by the invention, the three-dimensional digital twin model is constructed, and the building structure, the equipment layout and the material attribute data are integrated, so that the precise simulation of the environment is realized, the wireless network deployment accuracy is improved, the deployment scheme can better adapt to the dynamic change of the environment, and the deployment efficiency is improved. The improved O-FDTD algorithm is adopted to simulate electromagnetic field propagation in a building in real time, and the problem that the calculation efficiency is low when a traditional FDTD algorithm processes the metal edge effect and a moving object is effectively solved.

The invention belongs to the technical field of chips, and discloses a vehicle gauge-level SMD chip crystal and a processing method thereof, and the method comprises the steps: forming a gradient doped region on the surface layer of a quartz wafer through an ion implantation technology, and carrying out the recognition of the surface defects of the wafer and the etching of an anchor point groove based on a visual detection system; the etched doped quartz wafer is subjected to micro-electro-mechanical processing, a double-cantilever supporting structure is formed, a three-dimensional electromagnetic shielding layer is constructed on the surface of the wafer subjected to cantilever processing, a ceramic substrate and a metal conducting layer are alternately deposited through an additive manufacturing process, a polyimide-silicon dioxide colloid material is provided, and the three-dimensional electromagnetic shielding layer is formed; gradient distribution of an adhesive layer is realized through a micro-droplet jetting technology, a polyimide-silicon dioxide composite stress buffer layer is coated on a ceramic substrate, alignment and patch packaging are carried out on a processed crystal and a substrate, and through material modification and process collaborative optimization, the method is suitable for application in a high-temperature environment; the reliability problem in the extreme environment of the vehicle gauge is solved, and meanwhile the yield is improved.

The invention relates to a cooperative control method and system for realizing self-organizing protection of a multi-unmanned aerial vehicle cluster, and the method comprises the steps: M1, enabling the unmanned aerial vehicle cluster to execute a task, obtaining the data information of the remaining power, RSSI signal intensity and IMU attitude of each unmanned aerial vehicle in real time based on an airborne built-in sensor, and acquiring data information of distances and relative speeds of obstacles around the unmanned aerial vehicles in real time based on an airborne external millimeter-wave radar, constructing a dynamic threshold function stop, and if the RSSI signal strength of each unmanned aerial vehicle is greater than the stop, outputting data information of the residual electric quantity and IMU attitude of each unmanned aerial vehicle. According to the method, misjudgment (such as transient packet loss due to electromagnetic shielding) caused by temporary signal interference is effectively avoided, the misjudgment rate is reduced by 40%, unnecessary return or cluster recombination is reduced, continuous task execution is guaranteed, it is ensured that leader handover is completed quickly (at the millisecond level) when a host fails, and the situation that a cluster falls into disorder due to single-point failure is avoided.

The invention relates to a preparation method and system of a high-performance electronic tag in the field of electronic tag manufacturing, and the method comprises the steps: obtaining the working parameters of a high-frequency / NFC electronic tag in a high-temperature environment, analyzing the conductivity change trend of an antenna material, building a mathematical model of the influence of the high-temperature environment on the antenna material, and obtaining the high-performance electronic tag according to the model. Adjusting the component proportion of the antenna material to obtain an optimized antenna material formula; on the basis of optimizing an electromagnetic shielding scheme, comprehensive performance data of a high-frequency / NFC electronic tag in different environments are collected, a performance prediction model under the coupling action of multiple environmental factors is established, the model is adopted to simulate the working state of the tag in a complex working condition, and the performance stability of the tag is judged; after an antenna pattern is precisely processed, characteristic data of all layers of materials of the high-frequency / NFC electronic tag are collected, a relation model of material characteristics and bonding strength is established, and interlayer bonding force is enhanced by adopting a plasma surface treatment technology, so that an optimized bonding process scheme is obtained.

An item managing apparatus includes: an item attachment device including a linear member and a biasing member, the linear member including one end that is attached to an item, the biasing member biasing the linear member from the one end in a first direction; a communication device attached to the linear member; and a device accommodation part that can accommodate the communication device, the device accommodation part being configured to exert an electromagnetic shielding function for the communication device when the communication device is accommodated in the device accommodation part. When no external force is applied to the item against biasing force of the first direction generated by the biasing member, the communication device is accommodated in the device accommodation part, and when external force is applied to the item against the biasing force of the first direction, the communication device is enabled to exit from the device accommodation part.

The invention discloses an intelligent wiring optimization method and system for an HDI circuit board, and relates to the technical field of electronic circuit optimizing.According to the intelligent wiring optimization method and system for the HDI circuit board, by arranging an electromagnetic compatibility monitoring module and a thermal management evaluation module, the electromagnetic interference index Em and the thermal aggregation index Thc of the HDI circuit board are monitored in real time and evaluated; an optimization early warning signal is triggered and a thermal management optimization suggestion is generated, so that the problems of electromagnetic interference and insufficient heat dissipation are accurately solved; by calculating and evaluating a comprehensive optimization index COP, the electromagnetic shielding and heat distribution balancing capability is improved; and finally, by calculating and evaluating an optimization performance evaluation coefficient OPE, a dynamic adjustment module adjusts wiring parameters and optimizes a path in real time, iterative optimization is performed in combination with a real-time feedback mechanism, and finally a wiring scheme meeting requirements is output, so that the problems of low automation degree and poor optimization effect of an existing system are solved, and the system is suitable for popularization and application. And the requirement of wearable equipment on high performance of the HDI circuit board is met.

A radio frequency (RF) feedthrough component having an impedance greater than 20 ohms is disclosed. The feedthrough includes a ceramic body having a flexible non-ferrous conductor adhered to its outer peripheral surface and to an inner peripheral surface of an aperture through the ceramic body. A non-ferrous conductive lead is disposed through the aperture and protrudes from at least one side thereof. A non-ferrous hermetic seal is formed between a portion of the non-ferrous conductive lead disposed in the aperture and the non-ferrous conductor adhered to the surface of the aperture. The RF feedthrough can be assembled in an opening of a conductive housing to form an electromagnetically shielded package for an electrical circuit.

The invention discloses an integration and optimization method of a multilayer circuit board in a photovoltaic inverter, and the method comprises at least seven layers of functional stacked structures which are an electromagnetic shielding layer, a power device layer, a first insulating dielectric layer, a control circuit layer, a second insulating dielectric layer, a heat dissipation substrate layer and a mechanical strengthening layer from top to bottom in sequence. Wherein the power device layer adopts a three-dimensional embedded packaging technology to integrate an IGBT module and a SiC MOSFET module, and a gate drive circuit of the power device layer is embedded into a first insulating dielectric layer in a coplanar waveguide structure; the heat dissipation substrate layer is provided with a micro-channel array with gradient apertures, and the inner wall of each micro-channel is subjected to anodic oxidation treatment to form an Al2O3 ceramic layer with the thickness of 20-50 microns.

The invention provides an embedded substrate and a manufacturing method thereof. The manufacturing method specifically comprises the following steps: forming a conduction copper column and a shielding copper column on a first circuit layer of the substrate; pressing a second dielectric layer on the first circuit layer, the conduction copper column and the shielding copper column; mounting a component on the second dielectric layer; pressing the component into the second dielectric layer to enable the shielding copper column and the first circuit layer to surround the component; pressing a fourth dielectric layer on the second dielectric layer and the component, and curing the second dielectric layer and the fourth dielectric layer; forming an outer circuit layer on the fourth dielectric layer; and the outer circuit layer is in conducting connection with the conducting copper column, the shielding copper column and the terminal of the component. The shielding copper columns can reduce the deviation of the component in the extrusion process of the component and improve the yield, five surfaces of the embedded component are all provided with metal copper, and a good electromagnetic shielding effect can be achieved. Moreover, the second dielectric layer and the fourth dielectric layer are made of high-thermal-conductivity materials, so that heat can be quickly guided into the shielding copper columns, and the heat dissipation effect is obviously improved.

The invention discloses an electromagnetic shielding method for a high-density integrated wireless audio module, and the method comprises the steps: employing a metal material with good conductivity and corrosion resistance, such as aluminum alloy and copper alloy, to cover the outer surface of the module, and enabling the outer metal shielding layer to be used for isolating external electromagnetic interference; the thickness of the outer metal shielding layer is generally 0.3 mm to 1 mm, it is ensured that external electromagnetic radiation can be effectively reflected or absorbed, and the outer metal shielding layer is located between the outer metal shielding layer and the inner conductive coating and is made of a material with high-frequency absorption performance, such as a ferrite material, a conductive polymer or a carbon-based material. The thickness of the wave-absorbing layer can be designed according to the electromagnetic characteristics of a working frequency band and is generally 0.5 mm to 2 mm, so that high-frequency noise can be effectively attenuated. By adopting a multi-layer shielding structure and an intelligent heat dissipation design, electromagnetic interference is effectively reduced, miniaturization and light weight of the wireless audio module are maintained, and compared with the prior art in which a large number of expensive shielding materials are needed, the wireless audio module has the advantages that the selection of the shielding materials and the intelligent heat dissipation design are optimized.

The invention discloses a dynamic electromagnetic shielding method for a complex electromagnetic environment and a shielding device thereof, and the method comprises the steps: obtaining real-time voltage data in the complex electromagnetic environment, carrying out the voltage feature analysis, outputting a feature vector of a real-time voltage signal, and analyzing the type of an interference source of a current electric field according to the feature vector, performing interference trend time sequence prediction processing on the feature vector through a pre-trained LSTM model according to the interference source type to obtain a time domain voltage value and a phase deviation value, and performing composite loss coefficient calculation on the time domain voltage value and the phase deviation value to obtain a composite loss coefficient; and performing reverse offset signal synthesis processing on the voltage interference signal according to the calculated composite loss coefficient, performing coil dynamic activation processing on a preset multi-coil array according to the synthesized reverse offset signal, generating a directional offset magnetic field corresponding to the real-time electromagnetic interference, and performing electromagnetic offset shielding on the current electromagnetic interference. According to the invention, transient interference can be responded in time, and the electromagnetic shielding effectiveness can be improved.

The embodiment of the invention provides a flexible circuit board and electronic equipment, relates to the technical field of signal transmission, and is used for relieving the problem of relatively high signal loss of an FPC (Flexible Printed Circuit) caused by electromagnetic shielding. The flexible circuit board may have a first region and a second region. A reference layer of the flexible circuit board is located in the first area, and the reference layer and the signal layer are stacked. The first shielding layer is located in the first area, and the first shielding layer is stacked on the side, away from the reference layer, of the signal layer. The second shielding layer is located in the second area, and the second shielding layer and the signal layer are stacked. The first grounding wire is electrically connected with the first shielding layer and the reference layer. The first grounding wire is also electrically connected with the second shielding layer. A backflow signal of a signal transmitted by the signal line in the signal layer can flow through the first grounding line from the second shielding layer in the second area, and respectively flows into the first shielding layer and the reference layer in the first area.

The invention discloses a preparation method of a heat conduction and electromagnetic shielding self-healing polyurethane composite material, which comprises the following steps: modifying nano cellulose CNF (denoted as CNF-coated PPA) by using polyphenol amine PPA, and depositing silver nanoparticles on the surface of the CNF-coated PPA in situ to obtain a deposited material; the preparation method comprises the following steps: preparing a polyamide epichlorohydrin PAE solution, modifying graphene nanosheets GNP by using the PAE solution, and recording the modified graphene nanosheets GNP as PAE-GNP suspension liquid; cNF (at) PPA (at) Ag is dispersed into the PAE-GNP suspension liquid, and the CNF (at) PPA (at) Ag suspension liquid is marked as CNF-GNP suspension liquid; and preparing waterborne polyurethane WPU, dispersing the CNF-GNP suspension into the WPU, and carrying out vacuum filtration, drying and hot pressing on the mixed solution to obtain the polyurethane composite material. The method is simple in preparation process, mild in reaction condition and stable in product quality, and the polyurethane composite material prepared according to the method has excellent heat conduction, electromagnetic shielding and self-healing performance.

The invention relates to the technical field of power transmission and cable monitoring cables, in particular to an anti-interference optical fiber monitoring cross-linked cable and a forming and manufacturing method, and the cable sequentially comprises a cable core layer, a monitoring function layer, an electromagnetic shielding layer, an insulation protection layer and an outer protection layer from inside to outside; the monitoring function layer is tightly wound on the outer surface of the cable core layer in a spiral shape, the electromagnetic shielding layer is located between the monitoring function layer and the insulation protection layer, the electromagnetic shielding layer is of a multi-layer structure, the inner layer of the electromagnetic shielding layer is a permalloy belt, and the outer layer of the electromagnetic shielding layer is a tinned copper woven mesh. And a plurality of rat-proof and ant-proof composite layers are arranged on the outer side wall of the outer protective layer at intervals along the length direction of the outer protective layer. The monitoring function layer is spirally and tightly wound on the outer surface of the cable core layer, the design enables the optical fiber and the cable core layer to be tightly attached, it is ensured that the temperature change and mechanical deformation of the cable core layer can be rapidly transmitted to the optical fiber, and the problem of monitoring lag caused by gaps in a traditional loose tube structure is solved.