889 results about "Phase conversion" patented technology

The gel preparation has the merits of both solution and gel. By means of the combination of different type poloxamers, ocular in-situ gel preparation containing medicine and water soluble polymer supplementary material is prepared. The preparation contains poloxamer 407 and poloxament 188 as well as water soluble polymer supplementary material less than 3%. The preparation has proper phase conversion temperatur and may form gel on the surface of cornea of living body after being applied in liquid state at room temperature. The present invention can delay the disappearance of medicine and raise the biological utilization in some local area and is suitable for various ocular medicines.

A process and system for producing hydrocarbon compounds or fuels that recycle products of hydrocarbon compound combustion—carbon dioxide or carbon monoxide, or both, and water. The energy for recycling is electricity derived from preferably not fossil based fuels, like from nuclear fuels or from renewable energy. The process comprises electrolysing water, and then using hydrogen to reduce externally supplied carbon dioxide to carbon monoxide, then using so produced carbon monoxide together with any externally supplied carbon monoxide and hydrogen in Fischer-Tropsch reactors, with upstream upgrading to desired specification fuels—for example, gasoline, jet fuel, kerosene, diesel fuel, and others. Energy released in some of these processes is used by other processes. Using adiabatic temperature changes and isothermal pressure changes for gas processing and separation, large amounts of required energy are internally recycled using electric and heat distribution lines. Phase conversion of working fluid is used in heat distribution lines for increased energy efficiency. The resulting use of electric energy is less than 1.4 times the amount of the high heating value of combustion of so produced hydrocarbon compounds when carbon dioxide is converted to carbon monoxide in the invention, and less than 0.84 when carbon monoxide is the source.

A method for reducing a peak-to-average power ratio (PAPR) in an orthogonal frequency division multiplexing (OFDM) communication system including N carriers, among which L carriers are allocated to L reserved tones and data are carried by (N-L) remaining tones, wherein L is smaller than N, including generating an impulse signal from the L reserved tones; converting a phase of the generated impulse signal into a phase of a signal having a maximum peak value from among complex output signals obtained though inverse fast Fourier transform (IFFT) of the N carriers; scaling the generated impulse signal by the difference between the maximum peak value and a target power value; and complex-adding the scaled signal and the complex output signal after IFFT.

The invention relates to a method for suppressing an output harmonic wave and a direct current component of a single-phase grid-combined photovoltaic inverter. In the invention, an original voltage and current detection device and a digital controller in a photovoltaic grid-combined generation system are utilized, and the controls to the Boost circuit duty ratio and an inverter are increased on the basis of an original control algorithm. A phase current signal output by the inverter is subjected to single-phase conversion, actually output current is compared with a reference value, and a difference value is subjected to PI regulation to obtain a voltage control command of a fundamental wave and a harmonic wave; a direct current component detection value obtained by calculating the phase current signal and a given calibration currents difference value are processed to obtain a direct current component suppression voltage command; and after a control command of instantaneous fundamentalwave voltage, a control command of instantaneous harmonic wave voltage and the direct current component suppression voltage command are added and processed to obtain a control command used for the inverter. The invention realizes the control of the active and reactive current of the inverter, the elimination of the designated harmonic wave and the suppression of the direct current component and can effectively improve the electric energy quality of the grids.

A digital direct conversion receiving apparatus, including: a phase conversion unit to down-convert a Radio Frequency (RF) signal into a plurality of sample signals, and generate a certain phase difference among the plurality of sample signals when the RF signal is down-converted; and a variable complex gain unit to remove an image component from the plurality of sample signals using the generated phase difference.

The motor control device includes a current detecting portion for detecting a phase current that flows in an armature winding of a stator of a three-phase motor based on current that flows between an inverter for driving the motor and a DC power supply. The motor control device performs a position sensorless vector control for the motor based on a control current that is obtained by a three-phase to two-phase conversion of the phase current based on an estimated rotor position of the motor. The motor control device farther includes a superposing portion for superposing a superposed voltage having a predetermined frequency on a drive voltage for driving the motor and an estimating portion for deriving the estimated rotor position based on the superposed current that is extracted from the control current and flows in the motor in accordance with the superposed voltage. A voltage vector locus of the superposed voltage from the superposing portion presents an ellipse.

The embodiment of the invention discloses a microphone-array speech-beam forming method, which comprises a digital-signal converting step, a frequency-region signal-obtaining step, a time-delay obtaining step, a time-delay compensating step and a weighted stacking step, wherein time-delay estimation based on phase conversion is adopted particularly in the time-delay obtaining step, thereby a beam-forming signal pointed to a target sound-source spatial position after enhancement processing is obtained. Compared with the prior art, the positioning precision and the directivity of a three-dimensional space are enhanced, the long-distance sound-picking capability in a complicated acoustics environment is greatly enhanced, high-quality voice signals are obtained, and noise and other interferences are reduced. The embodiment of the invention also discloses a speech-signal processing device and a system.

The motor control device includes a current detecting portion for detecting a phase current that flows in an armature winding of a stator of a three-phase motor based on current that flows between an inverter for driving the motor and a DC power supply. The motor control device performs a position sensorless vector control for the motor based on a control current that is obtained by a three-phase to two-phase conversion of the phase current based on an estimated rotor position of the motor. The motor control device farther includes a superposing portion for superposing a superposed voltage having a predetermined frequency on a drive voltage for driving the motor and an estimating portion for deriving the estimated rotor position based on the superposed current that is extracted from the control current and flows in the motor in accordance with the superposed voltage. A voltage vector locus of the superposed voltage from the superposing portion presents an ellipse.

The invention discloses a method for preparing hypovanadic oxide powder-doped material, which belongs to the production and preparation field of inorganic functional materials and relates to the preparation of hypovanaic oxide powder doped with W, Mo or W / Mo. The method comprises the following steps: mixing and evenly grinding a vanadium source, a doped raw material and an auxiliary agent, pouring the mixture after being molten at a high temperature and keeping the temperature for a certain period of time into cold water to be rapidly water-quenched, drying the formed gel to form dry gel, thermal-reducing the grinded dry gel in the reduction atmosphere, performing annealing treatment in a protective atmosphere, and realizing the crystalling phase conversion at a constant temperature so as to obtain M-phase VO2 with phase transition property. The phase transition temperature of the VO2 powder after doping can be effectively controlled by adjusting the W and Mo atom doping amount. The invention has remarkable advantage in the aspects of preparation cost, product performance, technique flow, friendly environment, economic profit, and the like, has easily available raw materials, simple and convenient synthesis, low requirement on the equipment and high product performance, is suitable for industrial production and has wide application of product.

The invention relates to a lining-reinforced hollow fiber membrane tube as well as a preparation device and preparation method thereof, belonging to the field of preparation of polymer hollow fiber microporous membranes. In the membrane tube, a film forming chimney is designed reasonably, a coating layer on a braided tube led from a coating machine is subjected to controllable steam diffusion-induced phase inversion firstly, and then enters a coagulating bath, so that an open-pore surface skin layer with high porosity is formed on a film separation layer, and the radial direction of the membrane layer is in an integral asymmetric and interpenetrating cell-shaped structure; a composite material is selected to prepare a transition layer, so that the transition layer has excellent adhesive force and hardness, excellent compatibility with a surface separation layer and tiny cubical contraction in a phase conversion process at the same time; optimized braided tube size and braiding densityare selected to ensure that the braided tube has lower flexibility; and a method capable of maintaining reasonable roundness and the like in the production process ensures that the lining polyvinylidene fluoride (PVDF) hollow ultrafiltration membrane tube has the advantages of integral asymmetric structure with high integrity, high-porosity surface separation layer, higher back pressure enduring capability and the like.

The invention discloses a method of preparing an antibacterial anti-pollution ultrafiltration membrane by adopting a silver-loaded nano composite material. The method comprises the following steps: preparing a nano material water dispersion solution, adding trihydroxymethyl aminomethane and dopamine hydrochloride, stirring and reacting for 2 to 12 hours, centrifugally washing, then drying to obtain a polydopamine-modified nano material; preparing a mixed solution containing the polydopamine-modified nano material, a silver-ammonium solution, a stabilizer and water, stirring for 2 to 12 hours, centrifugally washing, and then drying to obtain the silver-loaded nano composite material; dispersing the silver-loaded nano composite material in an organic solvent, adding a membrane material, stirring, completely dissolving the membrane material, and standing to obtain a membrane casting solution; and scraping the membrane casting solution into a flat membrane by utilizing a flat membrane scraping machine, immersing in a coagulating bath, and carrying out a phase conversion to obtain the antibacterial anti-pollution ultrafiltration membrane. The ultrafiltration membrane has good hydrophilia, durable antibacterial performance and excellent anti-pollution performance, has good antibacterial and sterilization effect for colibacillus, bacillus subtilis and the like; moreover, the silver nano particles stably exist in the antibacterial anti-pollution ultrafiltration membrane.

The preparation process of semi-interpenetration network hydrogel with quick temperature response includes the following steps: dissolving the monomer and cross-linking agent in deionized water; adding polyeleectrolyte, electrolyte and initiator through stirring under inertial atmosphere for 5-10 min, reaction at 0-30 deg.c for 2-48 hr, and collecting semi-interpenetration network hydrogel with quick temperature response. The hydrogel has not only quick temperature response, but also great gel strength, and its response speed may be regulated via altering the consumption and molecular weight of the polyeleectrolyte and salt concentration in the reaction liquid. The hydrogel has 90 sec dehydration rate over 95 % at the temperature over its phase conversion point, can reach dehydration balance in 2 min, and has good pH response and thus expanded application range, especially in biological and medicine fields.

The invention discloses a preparation method of a layer-by-layer self-assembled hollow fiber forward osmosis membrane. The preparation method comprises the steps of: preparing hollow fiber forward osmosis base film, modifying hollow fiber ultrafiltration base film, repeating layer-by-layer assembly of polycation and polyanion layers, performing interface cross-linking polymerization for preparinga selective functional layer, conducting moisturizing, and carrying out treatment and storage so as to prepare the layer-by-layer self-assembled hollow fiber forward osmosis membrane. The surface of the hollow fiber self-support base film which is prepared by using a phase conversion method is activated firstly, layer-by-layer assembly of polycation and polyanion is repeated on the surface of thefilm so as to form an functional polarization layer for an electrolyte solution, and the polyamide selective layer is prepared through interfacial chemical cross-linking polymerization. The prepared hollow fiber forward osmosis membrane has a controllable thickness and an internal polarization layer with a high charge capacity, and the internal concentration polarization phenomenon can be alleviated effectively during the forward osmosis process; therefore, the hollow fiber forward osmosis membrane can simultaneously obtain high flux and low reverse salt flux, has high filtration separation efficiency, easy cleaning and a long service life, and can be widely applied to seawater desalination and concentration and desalination of brine.

A reinforced type polyvinylidene fluoride hollow fiber hydrophobic membrane belongs to an organic-inorganic hybridization membrane. For a commonly-used organic polymeric membrane has lower mechanical strength and shorter service life. In the invention, the reinforced type polyvinylidene fluoride hollow fiber hydrophobic membrane is prepared by adding hydrophobic inorganic nano particles in casting membrane liquid through utilizing a phase conversion method. The reinforced type polyvinylidene fluoride hollow fiber hydrophobic membrane is prepared by the following compositions in the casting membrane liquid in percentage by weight: 10-35 percent of high-molecular polymer, 1-20 percent of inorganic nano particles, 0-25 percent of an addition agent and 60-85 percent of solvent. For the hollow fiber hydrophobic membrane, the outer diameter ranges from 0.5 to 2.5mm, the wall thickness ranges from 0.05 to 0.5mm, the porosity ranges from 50 to 90 percent, and the membrane aperture ranges from 0.01 to 1mum. The hollow fiber hydrophobic membrane is simple in membrane forming technique, convenient to operate, and easy to realize industrial production; and the prepared hollow fiber hydrophobic membrane is good in hydrophobicity, high in water flux, strong in chemical stability, excellent in mechanical performance and high in retention efficiency and has wide application prospect.

The invention provides a super-resolution confocal microimaging device based on a column polarization vortex beam. The super-resolution confocal microimaging device comprises a pinhole filter, a collimating lens, a polarization and phase transformation system, a pupil filter, an optical filter, a detector and a three-dimensional translational platform, wherein a beam emitted from a laser passes the pinhole filter to obtain a Gauss basic mode beam, the collimating lens collimates the Gauss basic mode beam into the parallel beam, the polarization and phase transformation system allows the parallel beam to pass and obtain the column polarization vortex beam with preset polarization and phase distribution, the pupil filter allows the column polarization vortex beam to pass and to be reflected through a beam splitter and focused on a to-be-detected sample through a collecting lens, light signals reflected from the sample pass the collecting lens and the beam splitter to be incident on the optical filter, and the optical filter only allows a fluorescence signal of the light signals to be transmitted, the fluorescence signal is focused on a detecting pinhole through the collecting lens and is detected and converted, through the detector, into an electrical signal to be output, the sample is placed on the three-dimensional translational platform, detection of the sample at different positions can be realized by moving the three-dimensional translational platform, and accordingly three-dimensional scanning imaging of the sample can be realized.

The present invention belongs to the field of porous polyvinyl chloride film material, and is especially super-hydrophobic porous polyvinyl chloride film and its preparation process. By means of solvent-precipitant phase conversion process, porous loose polyvinyl chloride film with surface micro structure of piled micron and nanometer level grains is prepared, and the film has water contact angle greater than 150 deg, water drop rolling angle smaller than 15 deg and extremely high super-hydrophobic property. The present invention provides new method of realizing super-hydrophobic characteristic of polymer film without modification of low surface energy matter and opens one new way of expanding the application fields of common plastics.

The invention discloses a hybrid DC (direct current) electric power transmission system comprising a passive filter, a rectifier converter transformer, a thyristor converter, a flat wave reactor, a DC electric power line, a multi-level converter and an inverse converter transformer. A twelve-pulse bridge converter based on a thyristor is arranged at a sending-end rectifier side, and a modularized multi-level converter is arranged at a receiving-end inverter side, thus eliminating the phase conversion failure of the traditional DC electric power transmission system fundamentally and being suitable for supplying power for multi-DC droppoint areas, passive networks or weak alternating current systems and other occasions. Compared with a light-type high-voltage DC electric transmission system, the hybrid DC electric power transmission system provided by the invention has the advantages that the number of expensive full-control devices is greatly decreased, the cost is reduced, the loss is reduced, the reliability is high, the control is flexible, and fewer reactive compensation devices are used. In addition, the hybrid DC electric power transmission system provided by the invention can be used as a black start power supply of a receiving-end alternating current system and is good in engineering application value.

The present invention relates to one kind of shape memory fiber prepared with shape memory polyurethane and its preparation process. The shape memory polyurethane is prepared with reversible phase component (A) and fixed phase component (B). The preparation process of the shape memory fiber includes the following steps: preparing polyurethane with the component (A) and the component (B); and wet spinning the prepared polyurethane to prepare shape memory fiber. The shape memory fiber the present invention provides has the following features: titer higher than 300 dtex, breaking strength of 1-1.5 CN / dtex, breaking elongation of 100-400 %, deformation fixing rate not lower than 90 %, deformation recovering rate not lower than 90 %, deformation recovering temperature range of the reversible phase from -10 deg.c to +60 deg.c, and phase conversion temperature higher than 100 deg.c.

The invention discloses a power load balancing system applied to a low-voltage power distribution network. The device includes phase conversion devices and a control master station; three-phase input ends of the phase conversion devices are electrically connected with the low-voltage power distribution network; single-phase output ends of the phase conversion devices are electrically connected with electricity consumption terminals, so that the load information of the electricity consumption terminals can be transmitted to the control master station; the control master station performs computation processing, and determines electricity consumption terminals which are on phases with large total load information and require phase switching, and phase switching signals which enable the electricity consumption terminals to switch to phases with small total load information from the current phases, and transmits the phase switching signals to corresponding phase conversion devices; and the phase conversion devices switch the electricity consumption terminals and make the same connected into connection phases of the low-voltage power distribution network according to the phase switching signals, so that the load of the electricity consumption terminals can be re-distributed, and therefore, the load of the electricity consumption terminals can be uniformly distributed on the three phases of the low-voltage power distribution network. With the power load balancing system applied to the low-voltage power distribution network of the invention adopted, the distribution of the load of the electricity consumption terminals between three phases can be adjusted with continuous power supply ensured, and the three-phase load balance of the low-voltage power distribution network can be realized, and line loss can be effectively reduced, and power supply quality can be improved.

A DPSK demodulator demodulates DPSK signals in a computationally efficient manner to reduce the power requirements of the DPSK demodulator. A DPSK signal is received, digitized, converted to its in-phase (I) and quadrature (Q) components and filtered to remove noise. The I and Q components are processed to determine a relative phase and frequency offset. The phase is adjusted using the frequency offset. The adjusted phase is converted to an absolute phase, which is then mapped to a symbol representative of one or more bits of data.

The invention discloses a polyvinylidene fluoride super-hydrophilic composite porous membrane and a preparation method of a silver-loaded super-hydrophilic membrane thereof. A blending method and a phase to membrane conversion method are adopted, a micro-nano-level rough surface is formed while the phase conversion is performed between a phase-splitting material and a main material, then the membrane material is soaked in a solution containing dopa compounds to perform surface modification, the surface is modified through the adoption of features of oxidation, auto-agglutination, crosslinking and adhesion of the dopa compounds to prepare the super-hydrophilic membrane, the weak reducibility of polydopa or polydopamine is further used for reducing silver ions, and finally the silver-loaded super-hydrophilic membrane surface is prepared through the reaction of the dopa compounds. The super-hydrophilic surface formed by the method and the silver-loaded super-hydrophilic surface thereof have durable super-hydrophilic performance and antibacterial property.

The invention discloses a high-performance flat plate type cellulose acetate / nano-titanium dioxide blended forward osmosis membrane, which is prepared by comprising the following steps: adding the following raw materials in percentage by weight: 7.0%-26.0% of cellulose acetate, 2.0%-16.0% of additives, 0.1%-5.0% of nano-titanium dioxide, 0.05%-0.1% of graphene, and a dimethylformamide or dimethylacetamide, N-methylpyrrolidine and acetone mixed solvent into a dissolving tank according to certain sequence, stirring and dissolving for 3-15h to be full and even at 25-90DEG C, thus obtaining blended forward osmosis membrane casting liquid; and preparing the high-performance flat plate type cellulose acetate / nano-titanium dioxide blended forward osmosis membrane on a supporting material by using a phase conversion method. According to the prepared forward osmosis membrane, 1M NaCl and deionized water are respectively taken as driving liquid and feed solution, the flux of pure water can reach more than 17.5L / m<2>.h during testing time of1h and the backward salt flux is less than 3.0g / m<2>.h.

The invention discloses a method for preparing a macromolecule hollow porous fiber membrane by using a chemical reaction inductive phase conversion method, and belongs to the field of membrane preparation. The method for preparing the macromolecule hollow porous fiber membrane by using the chemical reaction inductive phase conversion method comprises the following steps of: preparing a homogeneous membrane casting liquid; extruding the membrane casting liquid and a core liquid from a spinning nozzle, and forming a membrane in outer gel bath; and carrying out chemical post treatment on the prepared membrane, so as to obtain the hollow porous fiber membrane which is uniform in pore diameter, high in membrane flux and high in pollution resistance. The method for preparing the macromolecule hollow porous fiber membrane by using the chemical reaction inductive phase conversion method, provided by the invention, is characterized in that pores are formed by chemical reaction induction through changing the composition of the core liquid and the outer gel bath or types of chemical reaction porogens and utilizing the reaction among the core liquid, the outer gel bath and the chemical porogens, and therefore, the macromolecule hollow porous fiber membrane which is uniform in pore diameter distribution, good in pollution resistance, and high in flux.

The invention relates to a control device for a brushless direct current motor sensorless based on 12-beat control and a method thereof. The device comprises a direct current power supply, a three-phase inverter, a brushless direct current motor, a drive circuit of a power device of the three-phase inverter, a microcontroller and a rotor position detection circuit, wherein the direct current power supply is connected with the brushless direct current motor through the three-phase inverter; after the rotor position detection circuit is connected with the brushless direct current motor for detecting, an output signal is directly connected with an analog-to-digital conversion input pin of the microcontroller; and six-path output of the microcontroller is connected to the three-phase inverter through the drive circuit of the power device of the three-phase inverter. The method detects terminal voltage of an inactive phase winding in a two-pipe conducting region at PWM conducted moment by an analog-to-digital conversion unit embedded in an XC866 singlechip, and acquires back electromotive force zero crossing as accordance of 12-beat phase conversion, thereby reducing the requirement of the adopted control device of the brushless direct current motor sensorless on a peripheral circuit, and achieving the aims of not only effectively inhibiting electromagnetic torque pulsation, but also reducing the system cost.

The invention discloses a method and equipment for generating a preamble sequence. The method comprises the following steps of: generating a frequency domain ZC sequence; determining a format and a time domain sampling point number of a target preamble sequence; performing inverse discrete Fourier transform of a corresponding preset small point number on the frequency domain ZC sequence according to the time domain sampling point number of the target preamble sequence to obtain a time domain sequence; performing interpolation on the time domain sequence, and converting the length of the time domain sequence into a length corresponding to the time domain sampling point number of the target preamble sequence; acquiring a phase rotation angle according to an initial position of the preset frequency domain resource; multiplying the time domain sequence with the converted length and the phase rotation angle, and performing phase conversion; performing corresponding subsequent processing on the time domain sequence with the converted phase according to the format of the target preamble sequence; and adding a cyclic prefix to the subsequent processed time domain sequence. The preamble sequence generating method disclosed by the embodiment of the invention avoids the occurrence of Fourier transform of a large point number so as to improve the operation speed, reduce the calculation quantity, improve the generating speed and reduce the power consumption and the circuit area at the same time.

The invention relates to a kind of wave front measure method basing on the linearity phase conversion. It calibrates to get the recovery matrix of the corresponding relation between the relative change values of the sensor far field light intensity and the coefficient in the incidence wave front, according to the parameters of the wavelength of the lamp-house, the focus of the sensor, the image element of the imaging device and so on. The sensor is calibrated by non-astigmation ideal plane before used. The non-astigmation far field image is regarded as the base image. Measure the incidence beam containing the aberration wave front to get the far field image in this condition. It detracts the base image to get the D-value of the light intensity distribution and form light intensity D-value as predefined. The recovery matrix multiplies the light intensity D-value to get the coefficient of the aberration wave front. The invention possesses the advantages of high energy utilization ratio, little calculation and rapid calculating speed. It can be applied in the high real-time requirement field, for example, self-adaptation optics.

The present invention discloses conducting lithium gel film containing porous polymer skeleton and its preparation process. The preparation process includes following steps: 1. preparing porous polypropylene glycol modified polyvinylidene fluoride or polyether sulfone film through phase conversion; 2. preparing electrolyte through mixing carbonate, lithium salt, polyglycol and diisocyanate at 10-20 deg.c; 3. soaking the porous film in the electrolyte at 10-20 deg.c for 10-30 min; and 4. treating electrolyte adsorbing porous film at 60 deg.c for 8-10 for cross-linking to form gel. The conducting lithium gel film has high strength, stable shape, high lithium salt electrolyte loading amount and conductivity of 10<-3>-10<-2> S / cm, and is suitable for use in polymer lithium cell with integrated diaphragm and electrolyte.