326results about How to "No hysteresis" patented technology

The invention discloses an optical voltage transformer which is composed of a light source, a coupler, a polarizer, a phase modulator, a polarization delay optical cable, a collimating lens, a faraday rotary mirror, an electro-optical sensing unit, a photoelectric detector and a signal processing module, wherein the electro-optical sensing unit is composed of a bismuth germinate and an A and a B electrodes which are respectively installed on an upper and a lower panels of the bismuth germinate. The invention adopts the technical proposal that an electric field leads to the change of the refractive index of the sensing bismuth germinate in the electro-optical sensing unit, the phase difference of two cross-line polarized lights passing through the bismuth germinate is changed due to the Pockels effect, and the magnitude of the electric field can be indirectly measured by measuring two coherent lights.

The invention relates to a phase shift soft switch high frequency isolation photovoltaic grid-connected inverter which comprises a main circuit, a DSP control circuit, an ARM control circuit, and an auxiliary switch power supply circuit. The invention firstly provides a full digitalization control photovoltaic grid-connected generating system, wherein a high frequency full bridge phase shift circuit combined with a high and low frequency full bridge inverter circuit is main circuit structure, and high speed embedded digital signal processor DSPTMS320F2808 is a core. Maximal power point tracking of solar cell panel output power and isolation of photovoltaic direct current and electrical network alternating current are realized, software realizes phase-locked loop control, perfect grid-connected and islanding protection functions are provided, and the whole system can operate safely and reliably.

The invention discloses a method for synthesizing a composite molecular sieve by a microwave method and catalytic performance application thereof. In the method for preparing the composite molecular sieve by the microwave method, kaolin is taken as a raw material, inorganic silicate is taken as an additional silicon source, and the prepared composite molecular sieve is applied to the alkylation reaction of phenol and tertiary butanol. The method comprises the following steps of: adding a certain amount of sodium silicate into the kaolin serving as the raw material to synthesize a Y type molecular sieve precursor; and preparing a composite molecular sieve Y/MCM-41 by the microwave method by using hexadecyl trimethyl ammonium bromide serving as a template. The synthesized molecular sieve has two pore structures, namely micropores and mesopores; the specific surface area of a sample is more than 550 m<2>/g; the average pore size is roughly 2.7 nm; and the sample has a regular and ordered hexagonal pore structure. The synthesized molecular sieve has good catalytic effect on the alkylation reaction of the phenol and the tertiary butanol, and particularly the selectivity of 4-tertiary butyl phenol is up to 86.3 percent.

The invention provides a method for preparing fluorinated graphene through a microwave hydrothermal method. The fluorinated graphene is prepared by employing the microwave hydrothermal method and is rapidly heated by utilizing the change of the electric field and magnetic field in the space, the low-temperature (150-200 DEG C) temperature is realized, the reaction time (30-60 minutes) is greatly shortened, the energy consumption is reduced, and the preparation efficiency is improved. The adopted preparation method does not have temperature gradient in the reaction process, a hysteresis effect is avoided, and the reaction process is easy to control and fewer in influence factors; and the prepared fluorinated graphene is uniform in fluorine doping and high in experimental repeatability. The process conditions such as raw material ratio, reaction temperature and reaction time are adjusted, and the fluorinated graphene of different fluorine contents can be prepared. The prepared fluorinated graphene is high in yield, and the yield is up to 90-95 percent. The preparation method is easily popularized and applied.

The invention provides a real-time wide-scene monitoring synthesis method for a cloud data center room, which synthesizes a monitoring video into a wide-scene wide-angle video in real time by arranging two common cameras in a cloud data center room in the following steps: (1) carrying out a camera calibration and correction method; (2) matching key frames; and (3) carrying out a fusion method and a real-time wide-scene video synthesis method. The camera calibration and correction method (1) is characterized in that the inner parameter, the outer parameter and the distortion parameter of the camera are calibrated and corrected with a common checkerboard method in the computer visual domain to favorably correct the distortion of the camera; and a result is more scientific, objective and real; in the camera calibration and correction method which is the first step of the method, a calibration algorithm based on a plurality of free planes of Open computer vision (CV) is adopted, i.e. a 7*7 checkerboard image is held by hands, and the length and the width of each check are both 2cm; the checkerboard image is translated and rotated in front of a pickup camera to obtain images of different directions; and when enough images (at least 10 pieces) are collected, the inner parameter, the outer parameter and the distortion parameter of the pickup camera are obtained by a pickup camera calibration function of the Open CV so as to correct the frame image.

The invention discloses a control system for overcoming the low voltage ride through. The control system comprises a photovoltaic cell array, a three-phase inverter, a power grid and a controller, the three-phase inverter comprises a power switch circuit and a filtering circuit, the power switch circuit and the filtering circuit are sequentially connected between the photovoltaic cell array and the power grid in series, and the signal input end of the controller is respectively and electrically connected with the output end of the photovoltaic cell array, the output end of the power switch circuit and the output end of the filtering circuit to collect current or voltage signals. The signal output end of the controller is electrically connected with the switch tube signal end of the power switch circuit to conduct repetitive control, PI adjustment and net side voltage front feed on the collected current or voltage signals to output pulse width modulation signals for controlling communication of a switch tube, the current can smoothly pass through the photovoltaic inverter when low voltage (including zero voltage) faults of the power grid occur, and the synchronization current is output to the maximum degree.

Provided is a dual mechanical port magnetic conductance harmonic type electromagnetic gear composite permanent magnet motor which can be widely applied to industrial transmission fields such as wind power generation, electric automobiles, ship driving and server driving. The electromagnetic gear composite permanent magnet motor is characterized is that main transmission components of the electromagnetic gear composite permanent magnet motor consists of a stator formed of a stator iron core (9) and a stator winding (8) having 2ps poles, a permanent rotor formed of a rotor iron core (17) equipped with 2pr rotor permanent magnets (18) and an output shaft (16), and a salient pole magnetic conductance wave rotor (6) having Zb salient poles, wherein a numerical difference between the number of pole-pairs ps and pr is relatively small; and the stator, the permanent magnet rotor and the salient pole magnetic conductance wave rotor (6) are coaxially disposed, are mutually coupled through a radial air-gap magnetic field, and are mutually coupled in a salient pole straight axis area of the high-speed rotating salient pole magnetic conductance wave rotor (6) by using a principle of heteropolarity magnetic field attraction with a small pole difference so as to drive the permanent magnet rotor with a small pole difference to rotate at a low speed. Therefore, power speed changed and torque conversion controlled drive with no mechanical contact and no friction is realized.

The invention relates to a organic field effect transistor device comprising: an organic semiconductor layer; a source electrode arranged in electronic contact with the said organic semiconductor; a drain electrode arranged in electronic contact with the said organic semiconductor; a gate electrode; an electrolyte layer arranged between said gate electrode and said organic semiconductor layer; wherein the organic semiconductor layer comprises a semiconducting polymeric material comprising one or more blocks of conjugated polymer combined with one or more blocks of copolymer; preferably an amphiphilic copolymer. Also a method of producing the device, and a polyanionic polymer is provided by the invention.

The invention provides a method for preparing a nitrogen-doped bismuth tungstate powder photocatalyst through a microwave hydrothermal method. The method comprises the following steps of: adding de-ionized water into bismuth nitrate pentahydrate and sodium tungstate dihydrate serving as raw materials and urea serving as an N source, stirring to uniformly mix the raw materials, stopping the stirring and producing white precipitate; placing in an ultrasonic instrument to perform ultrasonic treatment for 10-30 minutes; performing complete precipitation reaction to obtain precursor of microwave hydrothermal reaction; transferring the precursor into a reaction kettle; reacting by using the microwave hydrothermal method for 30-90 minutes at 160-200 DEG C; and taking out of the reaction kettle, collecting the precipitate, cleaning and drying. The method has the advantages of low reaction temperature of about 180 DEG C and short reaction time of probability 50-60 minutes; and the prepared powder has high reaction activity and low energy consumption and is environmentally-friendly.

The invention relates to an electromagnetic controllable mechanical brake parking device which comprises action arms, an action arm installation seat, cylindrical compression springs, electromagnetic iron components and abrasion pieces. Two action arms are respectively connected on an upper end and a lower end of the action arm installation seat in a rotation mode, the cylindrical compression springs are arranged between the two action arms, two ends of each cylindrical compression spring are connected with the action arms on the upper side and the lower side respectively, the electromagnetic iron components are arranged inside the cylindrical compression springs and connected with the action arms on the upper side and the lower side, and two abrasion pieces are respectively arranged at the other end of each action arm. Compared with the prior art, electricity amount of the electromagnetic iron components is controlled to control frictional force among the abrasion pieces and a steel rail so as to achieve braking or parking of a vehicle, the abrasion pieces are compressed on the steel rail, most thermal load is born by the steel rail, the position of the vehicle is continuously moved, heat generated by the braking is rapidly dissipated on the steel rail, and the electromagnetic controllable mechanical brake parking device is suitable for being used for continuously-implemented brake of the vehicle on long-distance downhill.

The invention relates to laboratory waste water treatment, in particular to a laboratory waste water treatment method and a device. In the method, laboratory waste water is subject to internal electrolysis, micro electrolysis and biosorption in sequence; aeration is carried out along with treatment; sludge produced in waste water treatment is dried, and the drying treatment is characterized in that gas produced in the aeration process is used for drying the sludge. The device comprises an electric control system and a waste water treatment unit, wherein, the waste water treatment unit comprises an inner electrolytic cell, a micro electrolytic cell, a biosorption cell and a desilter which are sequentially connected from front to back; the inner electrolytic cell, the micro electrolytic celland the biosorption cell are all provided with an aeration system; in addition, the device of the invention is also provided with a sludge filtering cell for treating sludge. The method and the device of the invention can be widely applied in treating waste water in various organic chemical engineering laboratories.

The invention discloses a data indexing method based on string suffixes. The method comprises an index creation step and a data indexing step. The index creation step comprises the substeps that S1, data is written, metadata and row ID are extracted, and the string suffixes are added; S2, an index is created; and S3, transaction judgment is performed, wherein a data writing transaction is judged, if writing succeeds, a transaction lock is opened, and if writing fails, logic deletion is performed, and the data is recovered. The data indexing step comprises the substeps that S01, index matching is performed; S02, an index pointer list is acquired, wherein a coding value of the index is quickly positioned in a B+ tree, and leaf nodes of the value form the index pointer list containing keywords of the index; and S03, the data is read, and an index result is found according to an index pointer array. According to the method, starting from a language system of a non-Latin language family, a string suffix sorting algorithm and a B+ tree algorithm are utilized to construct the index with characters being units, and problems concerning efficiency and accuracy of fuzzy query are solved.

The present invention is directed to a magnetic sensor using a spin transfer torque device, including a spin transfer torque device configured such that the magnetization direction thereof is varied by current, a bipolar pulse source configured to apply bipolar pulses to the spin transfer torque device in order to control the coercive field and sensitivity of the spin transfer torque device, and a signal processing unit configured to calculate magnetic susceptibility or magnetic resistance by counting the parallel (P) or anti-parallel (AP) states of the spin transfer torque device in response to the applied bipolar pulses.

The invention belongs to the technical field of magnetic particle preparation, and discloses a method for preparing biocompatible coating controllable core-shell type magnetic particles. The method comprises the following steps: anchoring methylacrylic acid to the Fe3O4 particle surface through a simple coordination reaction between methylacrylic acid MAA and unsaturated iron ions on the Fe3O4 nano-particle surface to form a polymerizable structure Fe3O4-MAA; adding konjac glucomannan, methylacrylic acid, a crosslinking agent, initiator and template, directly polymerizing through a graft copolymerization method to form coating controllable core-shell type magnetic particles with biocompatibility. The method is simple in process and low in cost, and the product can be used in carriers of target magnetic field drug release materials, magnetic resonance imaging contrast agents, magnetic molecularly imprinted polymer and the like.

The invention provides a bionic fishtail underwater propeller and relates to the technical field of underwater robots. The bionic fishtail underwater propeller comprises a swing mechanism, a driving mechanism, a transmission mechanism and a shell, wherein the swing mechanism comprises an elastic sheet and a rigid tail fin fixed at a tail end of the elastic sheet; the driving mechanism comprises a steering engine; the transmission mechanism comprises a winder and a connecting line, the two ends of the connecting line are fixedly connected with the two swinging sides of the elastic piece respectively, and the winder is fixedly connected with the connecting line; and the shell comprises a head shell body and a tail elastic shell body. According to the bionic fishtail underwater propeller, the steering engine drives the winder to rotate in two directions, the winder drives the connecting line to drive the elastic piece to swing left and right, the swinging process is not limited by frequency, the hysteresis effect does not exist, fish body waves are bent and continuous, the bionic effect in water is good, the bionic fishtail underwater propeller has advantages of being simple in structure, easy to control, good in flexibility and high in bionic degree.

A method of predicting the discharge condition of an electric spark processing belongs to the field of the electric sparking processing and relates to the method of predicting the discharge condition of the electric spark processing. The method of predicting the discharge condition of the electric spark processing first adopts the progressive mapping test method of the discharge condition to treat a real-time interval discharging signal that is collected in the processing; after treated, discharging condition succession is used as an system input, the unit of which is cyclical analysis; the mathematical model and the prediction method of the discharging condition based on local-wave resolution are used to do calculation, and the obtained prediction discharging condition succession of the electric spark is used as system output; then the normative approach method of output domain is adopted to treat the prediction discharging condition succession which is in the output domain of the actual discharging condition succession; and finally, fit criterion and descriminant technique are used for calculating the prediction precision of the discharging condition of the electric spark. The prediction method provided by the invention has wide application, high prediction precision and good freshness, which also has not hysteretic property.

The invention discloses the synthesis of poly lactic acid by microwave radiation melt polycondensation method which comprises, (1) placing L-lactic acid on auxiliary reaction medium, increasing the system vacuum from 0.050-0.070 Mpa to 0.080-0.099Mpa, microwave radiating 30-50 min, obtaining prepolymer (OLLA), (2) charging catalyst into the prepolymer, microwave radiating 2-5 min under normal pressure, (3) under the condition of vacuum 0.085-0.1Mpa, microwave power 500-550W, radiating 25-50min, thus obtaining polylactic acid.