5 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 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 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.

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.