431 results about "Wave transmission" patented technology

The invention relates to the technical field of power systems, and discloses a power distribution network fault positioning method, device and equipment and a medium, and the method comprises the steps: synchronously collecting fault traveling wave data through a transformer area intelligent terminal and a feeder terminal disposed in a power distribution network; dynamically calculating traveling wave transmission parameters based on the topological information and the real-time operation parameters of the power distribution network; performing feature extraction and fusion processing on fault traveling wave data acquired by the transformer area intelligent terminal and the feeder terminal to generate a joint feature matrix; based on the joint feature matrix and the traveling wave transmission parameters, cooperative verification is carried out through the single-end positioning information and the double-end positioning information, and a fault section is determined; and performing fault type identification on the fault section by using the intelligent classification model, and performing consistency verification according to an obtained fault type identification result and the fault section to generate a fault diagnosis result. According to the invention, accurate positioning of the power distribution network fault can be realized, and the problems of positioning blind areas, high cost and easy misjudgment in the prior art are solved.

The invention discloses a phased-array antenna, the phased-array antenna comprises a plurality of antenna module units, each antenna module unit comprises a PCB and an integrated radome module, and the integrated radome module is arranged on the surface of the PCB; a feed network, a dielectric substrate and an antenna radiation patch are arranged on the PCB, and the PCB is used for realizing feed and partial radiation functions; the integrated antenna housing module comprises a honeycomb support, an antenna patch, a PET film and an antenna housing, the antenna patch is etched on the PET film, the honeycomb support, the PET film and the antenna housing are mutually connected to form an integrated structure, and the integrated antenna housing module is used for realizing wave transmission, bandwidth broadening and impedance matching. According to the phased-array antenna, the use cost of PCB materials is reduced, and the problem that the electrical performance of the phased-array antenna is reduced due to dielectric loss caused by excessive use of PCB materials is solved.

The invention discloses an optical fiber signal transmission system and method based on quantum noise encryption, and relates to the technical field of optical fiber communication, and the system comprises a composite modulation transmitting module, a dispersion compensation relay module, a coherent receiving module and a digital signal processor. The composite modulation transmitting module comprises an electro-optical modulator and a quantum noise randomization encoder; the dispersion compensation relay module comprises an adjustable dispersion compensator and a Raman amplifier; the coherent receiving module comprises a local oscillator laser and a 90-degree optical mixer; a digital signal processor includes a clock recovery unit and a maximum likelihood sequence detector. All the modules are sequentially connected and cooperatively work. And the adjustable dispersion compensator dynamically applies reverse dispersion compensation calculated based on a dispersion coefficient and a transmission distance according to the dispersion amount monitored in real time. According to the invention, through technologies of quantum noise encryption, dynamic dispersion compensation, Raman amplification, coherent reception and the like, safe and efficient transmission with single-wave 400Gbps and 100km transmission bit error rate less than or equal to 1 * 10 <-12 > is realized.

A nonreciprocal microwave transmission device includes a substrate, a transducer on a surface of the substrate and configured to reciprocally convert between electrical signals to acoustic waves, a first piezoelectric material configured to generates and transports acoustic waves from a signal applied to the transducer, and a thin film magnetic material configured to couple to acoustic waves through magnetoelastic coupling so as to have non-reciprocal magnetoelastic coupled acoustic wave transport. Transmission of acoustic waves through the thin film magnetic material is in a direction toward the transducer has a first magnitude and transmission of acoustic waves through the thin film magnetic material in a direction away from the transducer has a second magnitude, the first and second magnitude being significantly different.

The invention discloses an ultra-wideband RCS (radar cross section) reduction metasurface with mixed wave absorption and diffuse scattering and a wave-transparent window, and belongs to the technical field of electromagnetic metamaterials. The metasurface adopts a four-layer cascade structure and comprises a first layer of polarization conversion structure, a second layer of 2.5 D lossy structure, a third layer of Jerusalem cross-shaped lossy structure and a fourth layer of frequency selective surface structure. By loading a lumped resistor at a specific position and adopting a metal through hole interconnection technology, dual functions of radar cross section reduction in a 1-20GHz ultra-wideband and low insertion loss wave transmission in a 8-12GHz frequency band are realized. The structure of each layer adopts a highly symmetrical design and has the characteristic of polarization insensitivity, and meanwhile, by optimizing interlayer air gaps and dielectric material selection, the structure compactness is realized on the premise of ensuring the performance. The method has important application value in the aspect of integration of stealth equipment and a communication system.

The invention relates to the technical field of aerospace, in particular to a ceramic 3D printing A sandwich structure with a broadband wave-transparent characteristic. According to the ceramic 3D printing A sandwich structure with the broadband wave transmission characteristic, good compatibility of broadband wave transmission, strength-structure accuracy and reliability is achieved, an obvious effect on broadband wave transmission of 1 GHz to 18 GHz is achieved, the dielectric constant and the tangent loss are in a reduction trend under the same frequency band, excellent stability is shown, and the dielectric constant and the tangent loss are reduced under 10 GHz. The dielectric constant of the ceramic 3D printing A sandwich structure with the broadband wave transmission characteristic is reduced by 40% or above compared with that of a full solid structure, the wave transmission rate is increased by 50% or above, the ceramic 3D printing A sandwich structure has excellent electromagnetic performance and mechanical performance, and support is provided for implementation of reliable service application targets such as diversion, heat protection, wave transmission, bearing and rain erosion resistance of hypersonic aircrafts.

An apparatus is provided which comprises at least one processor, and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive a carrier wave transmission modulated by an ambient internet of things device in an ambient internet of things session, determine whether a received power of the carrier wave transmission is below a predetermined threshold; and in response to determination that the received power is below the predetermined threshold, prepare a notification requesting to control at least one carrier wave transmission characteristic such that the received power is increased, and transmit the notification to a carrier wave provider transmitting the carrier wave transmission or to a session control unit controlling the ambient internet of things session.

The invention provides a CEEMDAN-SSA-based power distribution network fault identification method, and the method comprises the steps: receiving a traveling wave signal of a power distribution network, and carrying out the preprocessing of the traveling wave signal; decomposing the preprocessed traveling wave signal by adopting CEEMDAN to obtain an intrinsic mode function component set, and selecting a high-frequency intrinsic mode function component from the intrinsic mode function component set; performing noise reduction on the high-frequency intrinsic mode function component by using singular spectrum analysis to obtain a pure fault feature signal; analyzing and reconstructing the frequency spectrum characteristics of the pure fault characteristic signal by using fast Fourier transform, and calculating the average frequency spectrum content of the low-frequency-band signal and the amplitude ratio of the high-frequency-band signal according to the frequency spectrum characteristics; and generating a fault identification result of the power distribution network by taking the average frequency spectrum content of the low-frequency-band signal as a main criterion and taking the amplitude proportion of the high-frequency-band signal as an auxiliary criterion according to the fault traveling wave transmission characteristics. Therefore, high-precision power distribution network fault identification can be realized in a complex working condition and a high-noise environment.

The utility model provides an on-line monitoring tube expansion prevention protection device for a round tube belt conveyor, and belongs to the technical field of conveyors. The online monitoring tube expansion prevention protection device for the circular tube belt conveyor comprises ultrasonic directional transmitters and ultrasonic directional receivers, the ultrasonic directional transmitters and the ultrasonic directional receivers are arranged on the two sides of the circular tube belt conveyor respectively, the number of the ultrasonic directional transmitters and the number of the ultrasonic directional receivers on each side are both two, and the number of the ultrasonic directional transmitters and the number of the ultrasonic directional receivers on each side are both two. The ultrasonic directional transmitter and the ultrasonic directional receiver which are in the opposite state are at the same height, and the ultrasonic directional transmitter, the ultrasonic directional receiver, the coal feeder and the round pipe belt conveyor are all connected with a round pipe belt conveyor PLC. According to the utility model, directional sound wave transmission and feedback receiving are combined with PLC control of the circular tube belt conveyor, so that the device has the advantages that the accumulation condition of materials in the rubber belt in the running and conveying process can be monitored on line in real time, and tube expansion is prevented fundamentally.

A frequency selective unit, a frequency selective surface, and an antenna base station. The frequency selective unit comprises a metal reflector plate and at least two conductive material pattern layers, wherein through holes are provided in the metal reflector plate, the at least two conductive material pattern layers run through the through holes, and there is a gap between the conductive material pattern layers and the metal reflector plate; and at least one conductive material pattern layer comprises a first transmission mode, and at least the other conductive material pattern layer comprises a second transmission mode, and in a transition band, electromagnetic waves in the two transmission modes have opposite phases and cancel each other, such that the electromagnetic waves cannot be transmitted through the frequency selective unit; moreover, an electromagnetic wave transmission zero can be generated in the transition band, and a sharp roll-off is formed at an out-of-band edge of a second band, thereby realizing high-frequency selectivity. The conductive material pattern layers are not parallel to the metal reflector plate, the transmission direction of the electromagnetic waves is parallel to the surfaces of the conductive material pattern layers, and it is not necessary to provide a metallized via hole between the at least two conductive material pattern layers to perform electrical connection, thereby simplifying the manufacturing process and processing difficulty of the frequency selective unit.

The invention discloses a micro-through-hole structure polymer metallization method for guided wave transmission, and belongs to the technical field of photoelectric device processing, a polymer substrate is used for replacing a traditional all-metal material, and the micro-through-hole structure polymer metallization method for guided wave transmission is achieved through the multi-stage processes of plasma activation, chemical coarsening, sensitization, chemical plating, electroplating and the like. And forming a compact and high-adhesion metal layer on the inner surface of the through hole of the polymer substrate. In the process, a microfluid pump or a peristaltic pump is adopted to drive the solution to circularly flow in the through hole and the microcavity. According to the micro-through-hole structure polymer metallization method for guided wave transmission, dynamic flowing of a chemical plating solution in a micro-through hole and an internal cavity is achieved by introducing a micro-fluid pump or a peristaltic pump, and therefore a uniform, compact and firmly-attached metal layer is obtained.

The invention provides a plasma transient time boundary-based terahertz wave spectrum regulation and control method and device, and the method comprises the steps: obtaining femtosecond laser and terahertz waves, and enabling the femtosecond laser and the terahertz waves to enter a terahertz wave transmission space through beam combination; when the femtosecond laser and the terahertz wave synchronously pass through a first position point, the terahertz wave after frequency spectrum regulation and control is obtained; the first position point is located in the terahertz wave transmission space, a time boundary caused by medium transient refractive index sudden change is formed at the first position point when the femtosecond laser ionizes gas to obtain plasma, and frequency shift occurs when terahertz waves pass through the time boundary. According to the invention, the modulation effect on the terahertz wave frequency demand can be realized according to the abrupt change of the refractive index caused by the transient generation of the plasma.

The invention relates to the technical field of electric power engineering, in particular to an electric power scene visual key information side end compression and transmission system, which comprises the following steps of: when wireless network transmission is invalid or does not meet the image data transmission requirement, loading a variable-length code with verification of an image at each sampling moment to a carrier wave in a millimeter wave reference signal form for modulation; obtaining a millimeter wave modulation signal; transmitting the millimeter wave modulation signal to a monitoring work station through a millimeter wave transmission channel, so that the monitoring work station demodulates the millimeter wave modulation signal and obtains image edge information; and when the light intensity is weak or the power scene is shielded, processing the multi-frame millimeter wave echo point cloud data, obtaining the information of the invasive or dangerous object, fusing the information with the edge information of the corresponding timestamp image, and then carrying out non-maximum suppression operation to obtain target fusion information. According to the invention, the transmission data capacity is reduced, the continuous transmission of information is ensured, the adaptability of the system in a complex network environment is enhanced, and the safe and stable operation of the power system is maintained.

The embodiment of the invention provides a multi-physical field collaborative simulation method and device for a high-speed silicon-based electro-optical modulator, and the method comprises the steps: building a physical model of the electro-optical modulator, carrying out the simulation under different bias voltage and temperature conditions, solving a Poisson equation, a carrier continuity equation and a drift diffusion transport equation, and obtaining the corresponding carrier concentration distribution; performing small-signal simulation analysis on the model to obtain corresponding PN junction electrical characteristic parameters; performing waveguide optical mode simulation on the model to obtain corresponding electric field mode distribution and effective refractive index, and calculating the effective refractive index and absorption coefficient change of the waveguide; constructing a traveling wave electrode model, simulating the traveling wave electrode model to solve an S parameter of a traveling wave electrode, and determining a distribution parameter of the no-load traveling wave microstrip line; a load traveling wave transmission line model is constructed in combination with PN junction electrical characteristic parameters, and based on the model, the frequency response characteristics and the modulation bandwidth of the electro-optical modulator at different temperatures are determined, so that the accuracy of a simulation result can be improved.

A metasurface unit is printed on a dielectric substrate by adopting a double-layer metal structure, a top-layer metal structure comprises a central cross-shaped metal patch, an edge square ring metal patch and rectangular metal patches on two sides, the central cross-shaped metal patch is placed at the central position of the dielectric substrate, and the edge square ring metal patch is placed at the central position of the dielectric substrate. The edge of the edge square ring metal patch coincides with the edge of the dielectric substrate, the rectangular metal patches on the two sides are placed between the central cross-shaped metal patch and the edge square ring metal patch and connected with the edge square ring metal patch, and a gap is reserved between the rectangular metal patches on the two sides and the central cross-shaped metal patch. PIN diodes are loaded at gaps between the rectangular metal patches on the two sides and the central cross-shaped metal patch; the bottom layer metal structure is obtained by rotating the top layer metal structure by 90 degrees according to the normal direction, and the top layer cross-shaped metal patch and the bottom layer cross-shaped metal patch are connected through a metal through hole. According to the invention, the self-adaptive switching wave transmission and reflection functions can be realized.

The invention discloses a multi-dielectric-layer pressure-resistant composite material and application of the multi-dielectric-layer pressure-resistant composite material in an antenna housing. The multi-dielectric-layer pressure-resistant composite material has a light high-strength structure and also has high wave-transparent performance. The multi-dielectric-layer pressure-resistant composite material specifically comprises a plurality of high-structural-strength surface layers and supporting core layers which are arranged in sequence, and the high-structural-strength surface layers are located on the outermost layer. The high-structural-strength surface layer is made of a fiber-reinforced resin-based composite material, and the supporting core layer is made of a low-density pressure-resistant composite material. Compared with the prior art, the multi-dielectric-layer pressure-resistant composite material provided by the invention has the following progress: the multi-dielectric-layer pressure-resistant composite material is low in dielectric constant, pressure-resistant and high in wave-transparent performance, can meet the index requirement that the insertion loss is less than 1.5 dB, and can also meet the pressure requirement of external pressure. And multi-frequency-band design can be carried out for different wave-transparent and pressure-bearing requirements.

The invention provides a permeable breakwater and a design method thereof, and relates to the technical field of permeable breakwater. Aiming at the lack of a design method for high-precision environment coupling and high-accuracy structure stress prediction during design of a permeable breakwater in the prior art, the method comprises the following steps: establishing a wave-structure-foundation coupling model based on structure stress data, environment soil characteristics and a transmission coefficient of waves; s5, selecting a wave-structure-foundation coupling model, simulating different structure parameter combinations based on the wave-structure-foundation coupling model, and when the simulation results do not meet the target requirements, circularly executing the steps S2 to S5 until the simulation results meeting the target requirements are screened out, and determining a corresponding final structure parameter combination. The cooperative working mechanism of the reduction foundation and the pile foundation is realized, the dynamic interaction of the wave load and the structural response is simulated, and the environmental coupling precision and the structural stress prediction accuracy are improved.

The invention discloses a frequency selection absorber design method based on cross-layer electromagnetic function decoupling mapping and cross-layer coupling electromagnetic network abstraction, which comprises the following steps: decoupling and mapping wave absorbing and wave transmitting function requirements to a set space region of a double-layer structure through cross-layer electromagnetic function decoupling mapping, forming a physical structure comprising an edge loss region, a central resonance region, a middle coupling region and a system wave-transparent resonance region; abstracting the physical structure into a unified model comprising a composite RLC integrated network, a band-pass resonance network and a coupling network through cross-layer coupling electromagnetic network abstraction; carrying out collaborative optimization on model parameters of the unified model so as to realize path collaborative control of electromagnetic energy of the frequency selection absorber under frequency band selection; and meanwhile, the ultra-thinness and robustness of the structure are realized. According to the invention, an integrated design normal form for solving functional contradictions in principle is adopted, and the inherent contradiction between broadband wave absorption and extremely low loss wave transmission is solved.

The invention discloses a temperature monitoring system suitable for a fusion reactor low-clutter system and an over-temperature protection method. The temperature monitoring system comprises a high-speed temperature acquisition unit, a thermocouple sensor, an industrial control upper computer and a database server. A microwave excitation signal of the microwave excitation source is amplified by the microwave source klystron and then transmitted to the low-clutter coupled antenna through the microwave transmission line, and a plurality of temperature measuring points are arranged on the waveguide surface of the microwave transmission line and the end face of the low-clutter coupled antenna. Measurement output ends of the thermocouple sensors are uniformly accessed and gathered into the high-speed temperature acquisition unit and are uploaded to the industrial control upper computer, and the industrial control upper computer records and stores acquired multi-channel real-time temperature data, control signal output values and alarm events into the database server. The method has the advantages that early warning and temperature regulation are carried out for potential thermal runaway faults, so that the equipment safety of a high-power microwave transmission device and the normal operation of a low-clutter current driving system are guaranteed.

The invention provides a high-temperature-resistant low-dielectric-loss cyanate ester-based composite material and application thereof to a radar-resistant high-power-density antenna housing, and meets the requirement of continuously improving the transmission power of antenna signals on the power-resistant performance of the antenna housing. The high-temperature-resistant low-dielectric-loss cyanate ester-based composite material disclosed by the invention is composed of a prepreg plate, a glue film and a honeycomb, matrix resins of the prepreg plate, the adhesive film and the honeycomb are all modified cyanate ester-based resins; the modified cyanate ester-based resin is prepared by blending and modifying benzoxazine resin, bismaleimide resin, phenolic resin, polyimide resin and cyanate ester resin. The cyanate ester-based composite material with high temperature resistance and low dielectric loss has the advantages of high wave transmission rate, low reflectivity, low thermal conversion efficiency, high heat dissipation efficiency and excellent heat resistance.

The application provides a traveling wave distance measurement method and device based on modal decomposition and transient energy spectrum, equipment, and a medium. The method comprises the following steps: performing variational modal decomposition on transient traveling wave signals of two substations to obtain a function set composed of multiple intrinsic modal functions; determining modal components from the two function sets based on a kurtosis energy joint criterion; determining transient energy sequences based on the modal components and multiple Teager energy operators; determining the arrival time of the wave head from the transient energy sequences based on an adaptive dynamic threshold method; and determining the fault point position based on the arrival time of the wave head, a preset line length, and a target traveling wave transmission speed. The kurtosis and energy can be used to capture the mutation point of the wave head at the signal level, the arrival time of the wave head can be determined based on the physical characteristics of the signal, noise can be suppressed by combining the modal components and the Teager energy operator, and efficient calculation and anti-interference can be realized without introducing a neural network model.

The invention discloses a method, a device, equipment and a medium for testing the wave transmission rate of an antenna housing of a vehicle-mounted mobile base station, which are applied to the technical field of rail transit. For different preset scenes, the turntable is controlled to drive the millimeter wave vehicle-mounted mobile base station, the radio frequency transmitting terminal and the antenna housing to be tested to rotate according to a rotation angular velocity curve of the rotation angular velocity changing along with time; the rotation angular velocity curve is set in advance based on an actual running velocity curve of the vehicle in a preset scene; acquiring the transmitting signal strength of the radio frequency transmitting end at each moment and the receiving signal strength of the ground base station in the rotating process of the rotary table; on the basis of each emission signal intensity and the corresponding reception signal intensity, obtaining actual wave transmission rate data changing along with the rotation angular velocity in the preset scene; determining whether the wave transmissivity of the to-be-tested radome meets the wave transmissivity requirement or not according to the standard wave transmissivity data and the corresponding actual wave transmissivity data which change along with the rotation angular velocity in each preset scene; the test accuracy of the antenna housing can be improved.

An acoustic manipulation device is disclosed for acoustic treatment of a fluid volume. The acoustic manipulation device comprises a transducer and a superstrate. The transducer comprises a transducer piezoelectric material and transducer electrodes configured to apply an electric field to the transducer piezoelectric material, the transducer having a transducer acoustic wave transmission surface and the transducer being operable to generate and propagate acoustic waves to the transducer acoustic wave transmission surface. The superstrate has a superstrate acoustic wave transmission surface detachably coupled to the transducer acoustic wave transmission surface. The superstrate further has or is coupled to a fluid volume acoustic wave transmission surface, the fluid volume acoustic wave transmission surface being configured to receive a fluid volume for interaction with acoustic waves generated by the transducer and transmitted to the fluid volume via the superstrate. The superstrate comprises a superstrate piezoelectric material.

The invention discloses an energy selection surface with a polarization conversion function, which is formed by periodically arranging a plurality of energy selection surface units with the same structure, each unit comprises a polarization conversion layer and an energy selection layer, and the polarization conversion layer is composed of two metal layers and three dielectric plate layers so as to realize the polarization conversion function; the energy selection layer is composed of two metal layers, two dielectric plate layers and an air layer so as to realize an energy selection function; the polarization conversion layer and the energy selection layer are separated by an air layer. According to the energy selection surface, through the combined action of the polarization conversion layer and the energy selection layer, the insertion loss of the energy selection surface can be lower than-1dB in a wave transmission mode in a working frequency band, and the polarization conversion efficiency exceeds 90%. In a protection mode, the energy selection surface shows a remarkable energy selection characteristic in an ultra-wideband range, the protection efficiency is superior to-20dB, and the energy selection surface is suitable for an aircraft antenna housing.

The present invention relates to a multi-layer structured wave trap transmission line with a back cavity, comprising a first metal layer, a first dielectric layer, a second metal layer, a second dielectric layer, and a third metal layer stacked in sequence. The first dielectric layer, the first metal layer, and the second metal layer form a waveguide structure, and the second dielectric layer and the third metal layer form a metal back cavity. The second metal layer is provided with at least one annular gap, and each annular gap is provided within the area enclosed by a grounding post, which is connected to the second metal layer and the third metal layer, respectively. Compared with the prior art, the present invention integrates the wave trap structure with microwave and millimeter wave devices based on the influence of the parameters of the wave trap transmission line on its performance, thereby achieving the introduction of the wave trap function without increasing the size of the components.

The embodiment of the invention relates to the technical field of millimeter wave antennas, and discloses a millimeter wave antenna and a radar system.The millimeter wave antenna comprises a waveguide structure, a metallization layer, an isolation structure and a welding structure, and the waveguide structure comprises a first waveguide assembly and a second waveguide assembly; the first waveguide assembly and the second waveguide assembly are oppositely arranged to form a combination surface, the combination surface is provided with a functional area and a welding area, the functional area forms a millimeter wave transmission channel, the metalized layer covers the waveguide structure, the isolation structure is arranged between the welding area and the functional area, and the metalized layer covers the isolation structure. The isolation structure is used for preventing the soldering tin from diffusing from the soldering area to the functional area, in this way, effective separation of the soldering function and the waveguide performance function can be achieved, the isolation structure can effectively prevent the soldering tin from diffusing to the functional area, and it is ensured that the geometric dimension and the internal state of the millimeter wave transmission channel are kept stable; and the consistency of the electromagnetic performance of the antenna core is maintained.

The application relates to a method, a system, a device and a storage medium for transmitting high-frequency signals based on millimeter wave transmission, and belongs to the technical field of data transmission. The method comprises the following steps: converting, by a wireless signal conversion IC of a wireless device, a first USB-Thunderbolt signal to be transmitted into a first millimeter wave transmission signal, transmitting the first millimeter wave transmission signal in a wireless mode, and transmitting the first USB-Thunderbolt signal to a USB-Thunderbolt chip; receiving and resetting, by a millimeter wave signal conversion chip, the first millimeter wave transmission signal into the first USB-Thunderbolt signal, transmitting the first USB-Thunderbolt signal to the USB-Thunderbolt chip, and distributing the first USB-Thunderbolt signal to different interfaces according to the signal type of the first USB-Thunderbolt signal. The application has the following effects: long-distance lossless high-frequency full-load transmission of wireless signals is realized, the signals are converted into millimeter waves for transmission, the transmission efficiency and length between devices are improved by taking advantage of the transmission advantages of millimeter waves, and the application is not limited by wires and is more flexible to use.

The preparation method of the narrow-band optical filter comprises the following steps: S1, cleaning the surface of a glass substrate; s2, putting the treated glass substrate into a tool clamp, and hanging the tool clamp into a cavity of a vacuum coating machine; s3, vacuumizing is carried out, the vacuum degree reaches 1.0 * 10 <-3 > Pa, and radio frequency ion source cleaning is carried out; s4, plating the first surface with a short-wave-pass film system; s5, after the first surface is plated with the short-wave pass film system, taking out the tool clamp and the glass substrate plated with the first surface after the cavity is cooled to 50-60 DEG C or below; s6, repeating the steps S1 to S3; s7, plating an antireflection film system on the second surface; and S8, after plating of the antireflection film system on the second surface is completed, the tool clamp and the glass substrate are taken out after the cavity is cooled to 50-60 DEG C or below. The transmittance of the prepared glass substrate together with the short-wave pass film system on the first surface and the antireflection film system on the second surface at a 0-degree test angle in a 530 + / -20 nm wave band (namely a narrow band) is more than 99.5% on average, and the transmittance cut off in 400-500 nm and 560-700 nm wave bands on the two sides of the narrow band is less than 0.3% on average.

The invention discloses an infusion medicine category identification method, system and device and a storage medium, and the method comprises the steps: carrying out the frequency mixing of a millimeter wave transmission signal and a reflection signal, obtaining an intermediate frequency signal, determining a first data pair sequence through fast Fourier transform based on the intermediate frequency signal, and obtaining a first data pair sequence; performing abnormal data deletion on the first data pair sequences of all the windows through an Euclidean distance function, and inputting the second data pair sequences into the trained generator to obtain a first feature vector output by the trained generator; and inputting the first feature vector into a trained classifier to obtain a category identification result of the to-be-identified infusion medicine output by the trained classifier, thereby realizing lossless identification, and improving the efficiency and accuracy of infusion medicine category identification.

The application provides a low-frequency antenna, an antenna array and an electronic device. The low-frequency antenna comprises a dielectric substrate and a plurality of radiation units arranged on the dielectric substrate. Each radiation unit comprises a ring-shaped radiation element and a frequency selective surface arranged in the ring-shaped radiation element, and the frequency selective surface and the ring-shaped radiation element are insulated from each other. Each ring-shaped radiation element is provided with a gap. The low-frequency antenna provided by the application has a relatively wide wave transmission characteristic, and can realize relatively independent regulation and control.