14 results about "Relaxation frequency" patented technology

The invention discloses a cable insulation moisture content estimation method, system and equipment based on relaxation frequency distribution and a medium, and relates to the technical field of cable insulation moisture content estimation.The cable insulation moisture content estimation method based on relaxation frequency distribution is characterized by comprising the steps that a cable sample is prepared; obtaining a relaxation current sequence by adopting a dielectric response analysis method, calculating relaxation current data by adopting an integral equation theory to obtain a relaxation frequency distribution function, and extracting characteristic parameters; establishing a moisture content estimation empirical formula, and establishing a moisture content estimation model; and estimating the moisture content of the cable sample according to the moisture content estimation model to obtain an estimation result. According to the invention, the cable does not need to be cut or disassembled or a special device does not need to be used for complex testing, and the method is suitable for monitoring a large-range power network. The method has high adaptability and can be widely applied to different scenes of a power system.

The invention discloses a method and a device for judging selectivity of a gas separation membrane by adopting a dielectric spectrum. The gas separation membrane comprises a two-dimensional gas separation membrane, the selectivity comprises the selectivity of CO2 in CO2 / N2 mixed gas; the method comprises the following steps: S1, measuring dielectric spectrums of the two-dimensional gas separation membrane in a range of 0.01-5MHz under different relative air humidity, and calculating dielectric relaxation time after obtaining a dielectric relaxation frequency; and S2, according to the dielectric relaxation time of the two-dimensional gas separation membrane under different relative air humidities, determining the selectivity of the two-dimensional gas separation membrane to CO2 in the CO2 / N2 mixed gas under different relative air humidities. The method can accurately predict the CO2 selectivity of the gas separation membrane during separation of CO2 / N2 mixed gas under different relative air humidity conditions, and provides technical support for research of efficient two-dimensional gas separation membranes.

The invention discloses an electric hot melting sleeve connection monitoring method for a polyurethane directly-buried thermal insulation pipe, and belongs to the technical field of electric hot melting sleeve installation monitoring. The method specifically comprises the steps that distributed electrode sets are embedded into annular contact surfaces on the two sides of an electric hot melting sleeve, and an electric coupling network is formed by the distributed electrode sets and a conductive enhancing structure in a polyurethane thermal insulation layer; during electrifying and heating, applying a broadband alternating current signal which is dynamically modulated and covers a dielectric relaxation frequency band of a melting interface to the electrode group; collecting electrode pair voltage response signals in real time, and resolving a complex impedance spectrum containing real part and imaginary part impedance components; analyzing real part impedance non-linear attenuation characteristics, and if the real part impedance non-linear attenuation characteristics do not accord with a rule, analyzing an imaginary part impedance phase angle fluctuation rule, extracting dielectric anomaly features, matching the dielectric anomaly features with a preset model, and performing early warning if the dielectric anomaly features exceed a tolerance range; and finally, positioning the spatial distribution of the fusion defects based on the impedance response of the electrode group.

The invention provides a multimodal data fusion analysis method and system for pregnant and birth health. The method comprises the following steps: acquiring enhanced Raman spectrum data of amniotic fluid of a pregnant woman and electrical impedance spectrum data of blood of the pregnant woman; extracting a half-peak width parameter and a displacement parameter of a characteristic peak in a preset range from the enhanced Raman spectrum data, and analyzing a dielectric relaxation frequency variation parameter of a preset frequency band from the electrical impedance spectrum data; performing correlation analysis on the half-peak width parameter, the displacement parameter and the dielectric relaxation frequency variation parameter to construct a multi-dimensional interaction parameter; performing multi-modal data fusion analysis on the multi-dimensional interaction parameters to obtain a multi-modal data fusion analysis result including an amniotic fluid embolism probability value so as to realize risk early warning of amniotic fluid embolism; according to the multi-modal dynamic coupling and cross-scale pathological modeling, the technical barriers of data dimension limitation, static analysis lagging and multi-modal data isolation in the prior art are overcome, and an innovative technical path is provided for early accurate early warning of amniotic fluid embolism.

The application discloses a method for predicting the limited mass transfer efficiency of a two-dimensional separation membrane by using dielectric spectrum, comprising the following steps: S1, respectively measuring the dielectric spectrum of water in the two-dimensional separation membrane and a reference membrane in the range of 10 ‑3 ~ 10 3 Hz, calculating the dielectric relaxation time after obtaining the dielectric relaxation frequency; S2, judging the limited mass transfer efficiency of water in the two-dimensional separation membrane according to the dielectric relaxation time ratio τ / τ0 of the dielectric relaxation time τ of water in the two-dimensional separation membrane and the dielectric relaxation time τ0 of the reference membrane; when the τ / τ0 is less than 1, it is judged that the limited mass transfer efficiency of water in the two-dimensional separation membrane is higher than that of the reference membrane; when the τ / τ0 is greater than 1, it is judged that the limited mass transfer efficiency of water in the two-dimensional separation membrane is lower than that of the reference membrane. The method can accurately predict the limited mass transfer efficiency of different types of two-dimensional separation membranes, effectively reflect the state and relative transmission rate of water in the interlayer of the two-dimensional separation membrane, and provide technical support for the research on the high-efficiency separation two-dimensional membrane.

The application discloses a safety measurement method, device and equipment of a multiphase flow pipeline and a medium, relates to the technical field of oil exploitation, and comprises the following steps: applying an alternating excitation signal to different electrode systems arranged on a target pipeline to obtain first electric impedance spectrum data and second electric impedance spectrum data of the target pipeline in a multiphase flow state. The first electric impedance spectrum data is converted into a complex dielectric constant, and a relaxation frequency is determined from the complex dielectric constant; according to the relationship between the relaxation frequency and the particle size, the crystal particle size is determined. According to the crystal particle size and the erosion time, the erosion loss is determined. The equivalent circuit model matched with the second electric impedance spectrum data is fitted to determine the corrosion characteristics. Based on the electric impedance spectrum technology, the accurate measurement of the particle size and the erosion corrosion of two scenes is realized, the method has the characteristics of simple operation, non-invasiveness and high measurement precision, and the safety transportation of the two-phase flow pipeline is ensured.

The invention discloses a method and a system for detecting effective heat capacity of mixed gas based on three-frequency-point sound velocity. The method comprises the following steps: deducing a relationship between a sound velocity frequency dispersion spectrum and effective heat capacity, a sound relaxation absorption spectrum and a sound relaxation process; based on the established relationship, according to the sound velocity measurement values of the three frequency points, reconstructing a sound velocity frequency dispersion spectrum depending on the frequency; extracting a relaxation characteristic value of the reconstructed sound velocity frequency dispersion spectrum; and reconstructing the effective heat capacity of the mixed gas by using the relaxation characteristic value. According to the sound velocity measurement method introducing three frequency points, the effective heat capacity of the mixed gas is reconstructed through different relaxation frequencies, relaxation intensities and relaxation times, the limitations of tedious operation, low measurement precision and the like caused by measurement of sound relaxation absorption spectrum coefficients are overcome, the detection accuracy is improved, and the measurement precision is improved. High-precision acquisition of the effective heat capacity of the mixed gas can be realized only by sound velocity measurement.

The invention provides an arc plasma post-arc relaxation characteristic evaluation method and device, and belongs to the technical field of electrical switch equipment, the process that arc plasma is converted from a non-equilibrium state to an equilibrium state is regarded as the process that electrons and heavy particles collide for heat transfer until the temperatures of the electrons and the heavy particles are the same; describing an electron distribution function by using a kinetic equation with a collision term, and calculating an electron relaxation frequency; and calculating relaxation time of collision between electrons, relaxation time of collision between electrons and heavy particles and relaxation time of collision between heavy particles according to the energy change rate and the relationship between the energy change rate and the temperature balance time, and taking the maximum value as final relaxation time. According to the method, the prediction model is high in precision, the prediction result is accurate, meanwhile, the test amount in novel insulating gas research and development work is reduced, the research cost and the design risk are reduced, and the research and development efficiency is improved.

The present invention discloses a low-loss oriented BaM hexagonal ferrite material covering the sub-6 GHz band and a preparation method thereof, based on Co with uniaxial anisotropy 2+ and Ru 4+ ion-combined substituted BaM hexagonal ferrite material, using goethite powder with a high aspect ratio synthesized by the hydrothermal method as a raw material to replace the iron red (Fe2O3) required in the traditional ferrite preparation process, enabling the Co 2+ / Ru 4+ ion-combined substituted BaM hexagonal ferrite to achieve oriented preferred growth, thereby greatly increasing the magnetic resonance frequency and meeting the requirements of the low-loss sub-6 GHz miniaturized antenna for a high operating frequency. Secondly, by adding low-melting-point Bi2O3, the particle size and magnetic domain width are increased, which can reduce the domain wall resonance relaxation frequency, resulting in an obvious separation between the natural resonance point and the domain wall resonance point, ensuring the low magnetic loss characteristics of this material.

The invention discloses a monitoring method for electrofusion sleeve connection of a polyurethane directly buried thermal insulation pipe, belonging to the technical field of electrofusion sleeve installation monitoring, which specifically includes: embedding a distributed electrode group in the annular contact surfaces on both sides of the electrofusion sleeve to form an electrical coupling network with the conductive enhancement structure in the polyurethane thermal insulation layer; when energizing and heating, applying a broadband alternating current signal with dynamic modulation and covering the dielectric relaxation frequency band of the molten interface to the electrode group; collecting the voltage response signals of the electrode pairs in real time, and calculating a complex impedance spectrum containing real and imaginary impedance components; analyzing the non-linear attenuation characteristics of the real part impedance, and giving an early warning if the rules are not met; analyzing the fluctuation law of the imaginary part impedance phase angle, extracting the dielectric anomaly characteristics, matching with a preset model, and giving an early warning if it exceeds the tolerance range; finally, positioning the spatial distribution of the molten defect based on the impedance response of the electrode group.

The application particularly relates to a dielectrophoresis precision grading method and device for boron-containing diamond micro-powder. The method comprises the following steps: dispersing the boron-containing diamond micro-powder in a dispersion medium with an electrical conductivity less than 10 ‑3 S / m; passing the dispersed suspension into a dielectrophoresis grading device; applying electrophoretic interference of a shielding surface charge with a frequency of 5-20 MHz in the device, and realizing precision grading according to particle size by dielectrophoretic force. The application adopts a two-stage coupling grading strategy: the first stage of a parallel plate electrode unit realizes pre-selection according to boron content by using Maxwell-Wagner relaxation frequency difference, and the second stage of an inclined electrode array unit realizes precision grading according to particle size, and more than 5 narrow distribution particle grades can be obtained by single operation, the particle size span value of each particle grade is less than or equal to 0.5, and the particle size-boron content two-dimensional grading is realized, the particle size of each collection area after grading is relatively concentrated, the overlapping degree between adjacent particle grades is low, and the needs of precision applications such as super-precision grinding, heat-conducting filler and the like are met.

The present application relates to a method, apparatus, computer device, storage medium, and program product for determining the center frequency of a radio frequency system. The method includes collecting a first magnetic resonance signal and a second magnetic resonance signal; determining a first frequency spectrum corresponding to the first magnetic resonance signal and a second frequency spectrum corresponding to the second magnetic resonance signal; determining a relative relaxation frequency spectrum based on the first frequency spectrum and the second frequency spectrum; determining a characteristic frequency of a target imaging nuclide in a target tissue by analyzing the relative relaxation frequency spectrum, and determining the center frequency of the radio frequency system according to the characteristic frequency. By using the method for determining the center frequency of the radio frequency system provided by the present application, a more accurate center frequency can be obtained.

The invention discloses a low-loss oriented BaM hexagonal ferrite material covering a sub-6 GHz frequency band and a preparation method thereof, based on a BaM hexagonal ferrite material jointly substituted by Co < 2 + > and Ru < 4 + > ions with uniaxial anisotropy, goethite powder which is synthesized by a hydrothermal method and has a high length-diameter ratio is used as a raw material, iron oxide red (Fe2O3) required in a traditional ferrite preparation process is replaced, and the low-loss oriented BaM hexagonal ferrite material covering the sub-6 GHz frequency band and the preparation method of the low-loss oriented BaM hexagonal ferrite material covering the sub-6 GHz frequency band are obtained. And the BaM hexagonal ferrite jointly replaced by Co < 2 + > / Ru < 4 + > ions realizes orientation preferred growth, so that the magnetic resonance frequency is greatly improved, and the requirement of a low-loss sub-6GHz miniaturized antenna on high working frequency is met. Secondly, by adding low-melting-point Bi2O3, the particle size and the magnetic domain width are increased, so that the domain wall resonance relaxation frequency can be reduced, natural resonance points and domain wall resonance points are obviously separated, and the low magnetic loss characteristic of the material is ensured.

This invention discloses a plasma electrode, an impedance measurement signal injection method, and a tumor edge recognition method, relating to the fields of electrosurgical instruments and biological tissue detection technology. To address the problems of traditional plasma surgery's inability to acquire tissue electrical properties in real-time and in situ, and its difficulty in accurately identifying tumor edges, this invention integrates two pairs of miniature measurement electrodes into the active electrode, with a ceramic-insulated microchannel on the back side; it uses multi-frequency signals superimposed at logarithmic frequency points of 1kHz to 5MHz, and injects them in parallel within 10ms after phase optimization using a genetic algorithm; it extracts the Cole relaxation frequency based on distributed relaxation time, and achieves rapid tumor edge recognition through offline pre-calculation and online processing. This invention achieves deep integration of ablation and sensing, enabling early determination of tissue type and improving the accuracy and safety of tumor resection.