137results about How to "Phase stable" patented technology

The invention discloses a method for switching main and backup clocks, which is applied to a system comprising a main clock board and a backup clock board. Clock generation chips of the main clock board and the backup clock board respectively track a common-frequency clock source of the respective clock board; the mutual transmission of the main and backup clocks and data is achieved through respective logic chips; when the main and backup clocks are to be switched, a pre-switching instruction is sent to the logic chip of the main clock board, and after receiving the instruction, the logic chip of the main clock board sends a synchronous instruction to the logic chip of the backup clock board; after receiving the synchronous instruction, the logic chip of the backup clock board sends an effective synchronous signal in a pulse form to the clock generation chip of the backup clock board; and the clock generation chip of the backup clock board stops the clock output when the synchronous signal is effective, and restores the clock output after first delay time when the synchronous signal is not effective, phase positions of the main and backup clocks are aligned, and the main and backup clocks are instructed to execute main and backup switching. The method cannot cause phase position transient variation, unstable system and poor reliability due to the switching, and simultaneouslyhas less occupied resources.

The present invention discloses a coherent microwave-radiation cold atomic clock; and an ion pump is connected with a vacuum catheter which is connected with a microwave cavity; a light window is fixed in the microwave cavity by quartz glass and three reflective mirrors; a pair of anti-Helmholtz coils and a pair of Helmholtz coils are fixed on the microwave cavity; a pair of rectangular coils are fixed on the microwave cavity; a magnetic shielding system is connected with a vacuum system; semiconductor laser provides captive light and beams of pump-back light; a semiconductor laser on the vertical cavity surface provides a plurality of beams of captive light; a voltage-controlled crystal oscillator is connected with a frequency synthesizers connected with a signal receiver and processor; the semiconductor laser on the vertical cavity surface is connected with the microwave cavity; a photoelectric detector and a microwave-power receiver are connected with the signal receiver and processor connected with the voltage-controlled crystal oscillator as well as the semiconductor laser on the vertical cavity surface. The present invention is characterized in that the structure is compact and the size is small, and has good stability, high accuracy as well as good applicability.

A decision feedback equalizer (DFE) for a receiver that can reduce jitter is disclosed. The DFE uses an equalizer structure that employs a symbol sampling operation at a decision device, also known as a slicer. In a receiver, the phase of a signal, such as an equalized signal, is typically estimated from zero crossings in the clock recovery operation. Fluctuations in these zero crossings makes phase of the reproduced clock unstable, which decreases error performance in an associated receiver. Embodiments advantageously align inter-symbol interference (ISI) canceling terms from a feedback filter (FBF) relatively well, and thereby provide equalization of a relatively large portion of a symbol period. This advantageously stabilizes the phase of an equalized signal and reduces jitter.

The invention provides an optical frequency comb generation device with the comb tooth frequency interval capable of being scanned. A signal generator form two output ends through a microwave power distributor, wherein the first output end is connected with a photoelectric phase modulator after passing through a first broadband microwave power amplifier, the second output end is connected with a photoelectric intensity modulator after sequentially passing through an adjustable microwave delay line and a second broadband microwave power amplifier, a continuous wave laser carries out output sequentially through the photoelectric phase modulator and the photoelectric intensity modulator , the photoelectric phase modulator and the photoelectric intensity modulator are cascaded, and the photoelectric intensity modulator has direct-current bias. The invention further provides an optical frequency comb generation method. According to the optical frequency comb generation device and method, broadband continuous frequency scanning and accurate arbitrary adjustment of the comb tooth frequency interval are achieved, a generated optical frequency comb is stable in phase, frequency and central wavelength, and tunable, the device is simple in scheme, and low in cost, and the optical frequency comb generation device and method meet the requirement for application in the fields such as the optical measurement field, the laser radar field, the laser spectroscopy field, the optical fiber sensing field, the optical communication field and the microwave photonics field.

An electronic circuit includes a first and a second PLL stage (PLL1, PLL2) that can be switched in parallel or in series depending on locking of the first one of the PLL circuits to an input signal (IN). When in parallel, only the second PLL circuit (PLL2) is actively supplying a clock signal to the output of the electronic circuit. The first PLL circuit (PLL1) continues trying to lock onto the input signal (IN). A lock detector (LD) monitors the locking status of the first PLL circuit (PLL1) to the input signal (IN) and, upon locking, sets switches (S1, S2) to couple the output of the first PLL circuit (PLL1) to the input of the second PLL circuit (PLL2), and to couple the output of the second PLL circuit (PLL2) to the input of the first PLL circuit (PLL1).

The invention discloses a 100% regenerated fiber spunlace non-woven fabric which uses recycled spunlace non-woven fabric leftover material as a raw material. The production method of the 100% regenerated fiber spunlace non-woven fabric includes raw material pretreatment, raw material retreatment, opening, mixing and impurity removing, carding and netting, spunlace and primary drying, and drying and product finishing. Opening adopts a non-holding manner; a carding machine is additionally provided with a fiber cohesion roller and uses air flow to assist stripping; spunlace water is recycled water which is circularly supplied by a multilevel water circulation processing system, and filtering manners including an air flotation filtering manner, a sand filtering manner, a metal filtering manner and a bag refined filtering manner are used to filter out impurities in water; a novel safe emulsion is used to treat a spunlace fiber net by adoption of an impregnation method or a foam method; the cohesion and the combination among the regenerated fiber can be effectively improved, and the physical performance of the spunlace non-woven fabric finished product is improved; hair falling and bit falling can be avoid during use of the spunlace non-woven fabric, the service life of the spunlace non-woven fabric is prolonged, or the use times of the spunlace non-woven fabric are increased; and the spunlace non-woven fabric has excellent water absorbing performance, is durable and laundering-resistant, and can be used with most of cationic type antibacterial agents.

The invention relates to a method for synthesizing tobermorite whiskers with fly ash as a raw material and belongs to the technical field of nanometer whisker products. According to the method, an addition agent and a calcium resource are mixed uniformly according to the Ca / N molar ratio of (1-1000): 1 to obtain mixed slurry, after the pH value of the mixed slurry is adjusted to be 11-14, the fly ash is added, and in a high-pressure closed container, the mixture reacts at the temperature ranging from 150 DEG C to 260 DEG C, so that the tobermorite whiskers are obtained; the addition agent is a surfactant; the surfactant is an amino compound or a derivative of the amino compound. According to the method, the industrial solid waste fly ash is used as the raw material, the synthesized tobermorite whiskers can serve as a high-quality silicate heat-preserving and fireproofing material, and after being separated and purified, the tobermorite whiskers can also serve as an inorganic addition agent of a function composite material. The method is simple, feasible and beneficial for promoting high value-added utilization of the fly ash resource, and the product can be applied to the fields of building materials, metallurgy materials, chemical engineering materials and the like.

The invention relates to a method for preparing phase change energy storage material in the MgCl2*6H2O-CaCl2*6H2O system. The method includes: firstly, mixing MgCl2*6H2O and CaCl2*6H2O to obtain mixture; and secondly, sequentially adding nucleating agent and thickening agent into the mixture, mixing well, and packing to obtain the phase change energy storage material with phase change temperature of 20 DEG C to 25 DEG C, wherein the MgCl2*6H2O in the mixture is 5%-30% in mass fraction, and each of the nucleating agent and the thickening agent accounts for 1%-10% of the mixture by weight. The method is low in cost and easy to implement, and the prepared phase change energy storage material is highly stable.

The invention provides a corrosion-resistant environmental-friendly zinc alloy and relates to the technical field of alloys. The corrosion-resistant environmental-friendly zinc alloy comprises the following components in percentage by weight: 3.6-5.8% of Al, 0.1-0.48% of Cu, 0.001-0.1% of Mg and the balance of Zn and inevitable impurities, wherein the mass ratio of Al to Cu is 8-30; the microstructure of the zinc alloy comprises an eta phase and a beta phase; the volume percentage of the eta phase is less than 50%. The alloy has excellent casting properties, corrosion resistance and polishingand electroplating properties, is applicable to components and elements of water heating bathroom accessories, small hardware accessories and the like manufactured through pressure casting and gravityor low-pressure casting.

The invention provides a method capable of achieving direct current component and alternating current component separation in human body pulse wave sample signals and a pulse signal acquisition system based on wavelet decomposition and reconstruction. According to the pulse signal acquisition system, the sample frequency is set in the range from 100 Hz to 200 Hz, and the layer number of the wavelet decomposition and reconstruction is automatically selected; firstly, direct current components in an original sample data sequence are separated; secondly, an arithmetic mean value of a direct current component sequence is taken out to serve as a direct current signal with the constant amplitude; thirdly, an alternating current signal (pulse wave) with the more stable amplitude and phase position is separated from the original sample data sequence according to the direct current signal for the application such as blood pressure calculation, blood oxygen monitoring and hemodynamics PWV monitoring to use.

The invention discloses a method for synthesizing copper diselenide nano-crystals in a polyhydric alcohol-based solution. The method comprises the following steps of: (1), dissolving weighed 0.25mmol of copper chloride dihydrate into 10ml of triethylene glycol, to obtain a stable positive ion source solution, in addition, adding 40ml of triethylene glycol into a three-necked flask, adding selenium powder, and adding 0.1g of polyvinyl pyrrolidone, to obtain a negative ion source solution, wherein the mol ratio of Cu / Se is 1:2, 1:1.9, 1:1.8 and 1:1.7 respectively; (2), slowly heating the negative ion solution, rapidly injecting the positive ion source solution when the negative ion solution is heated to 210-270 DEG C, and carrying out backflow reaction, so as to synthesize the CuSe2 nano-crystal solution. By adoption of the method, the components of a product can be controlled accurately, the phase is stable, the repeatability is good, the cost is low, the synthesizing temperature is low, and furthermore, the synthesized copper diselenide nano-crystal solution is safe and low in toxicity.

The invention belongs to the technical field of solar cells and particularly relates to a method for preparing a CuInxGaySez prefabricated layer by electrochemical deposition. The method comprises steps: in an electrical deposition solution, current pulse or voltage pulse is adopted to obtain a CuInxGaySez prefabricated layer on a cathode substrate through electrical deposition, and the current pulse or the voltage pulse comprises a positive pulse period when the current and the voltage are negative values on the deposition surface and a reverse pulse period when the current and the voltage are positive values on the deposition surface. According to the method, a reverse pulse method is used during the electrical deposition process, part of selenium is stripped back in an electroplating solution while the CuInxGaySez prefabricated layer is formed, generation of selenium balls is avoided, and thus the CuInxGaySez prefabricated layer which is uniform in compositions and stable in phase is formed.

The invention provides a multi-channel broadband microwave optical transmission link transmitter phase stabilizing device. The multi-channel broadband microwave optical transmission link transmitter phase stabilizing device comprises an optical transmission link, a phase measurement pilot frequency link, a delay measurement pilot frequency link and a controller; the optical transmission link splits a multiplexed light signal of an input light signal, a first light signal and a second light into multiple split light signals to achieve multi-channel transmission, wherein the first light signal and the second light signal are provided by the phase measurement pilot frequency link and the delay measurement pilot frequency link respectively; each split light signal is transmitted to a receivingpart along an optical fiber corresponding to the channel, the input light signals in the split light signals at the receiving parts are output as output light signals, and the first light signals andthe second light signals in the split light signals are fed back to the phase measurement pilot frequency link and the delay measurement pilot frequency link respectively, so that the phase measurement pilot frequency link and the delay measurement pilot frequency link measure phase differences and time differences of the various channels respectively; and the controller controls a phase compensation module to adjust the phases of the light signals of the various channels according to time difference measurement results and phase difference measurement results.

The invention discloses a high-entropy ferrite porous ceramic material as well as a preparation method and application thereof, and belongs to the field of inorganic functional materials. The chemical composition of the high-entropy ferrite porous ceramic material is (Mg<0.4-x>Co<x>Ni<0.2>Zn<0.2>Cu<0.2>)Fe<2>O<4>, wherein x is more than 0 and less than or equal to 0.2. The preparation method comprises the following steps: dissolving glycine, magnesium nitrate, cobalt nitrate, nickel nitrate, zinc nitrate, copper nitrate and ferric nitrate in water to obtain a mixed solution; adjusting the pH value of the obtained mixed solution, and conducting heating until the solution is subjected to combustion reaction to obtain precursor powder; and carrying out heat treatment, molding and sintering on the obtained precursor powder to obtain the high-entropy ferrite porous ceramic material. The high-entropy ferrite porous ceramic material disclosed by the invention integrates the advantages of a high-entropy effect and a foam structure synergistic effect, has a self-supporting capability and a high specific surface area, is convenient to transport, store and recycle, and has a good application prospect.

The invention discloses a weak signal anti-interference detection processing method and device based on a Wheatstone bridge. According to the method, a Wheatstone bridge is formed by adopting a plurality of sensor elements, a direct current signal UI is generated and loaded to the A end and the C end to drive the Wheatstone bridge, the Wheatstone bridge is used for detecting a weak signal and converting the weak signal into an electric signal, and voltage signals output from the B end and the D end are obtained; the differential signals are amplified by the following amplifiers A1 and A2; a gate circuit controls a signal at a fixed frequency, output signals F and E after pre-amplification and filtering are switched and output and are transmitted to a differential amplifier A3 through a square wave-to-sine wave conversion circuit, the signal is converted into a sinusoidal signal with fixed frequency output, and the output amplitude of the signal is determined through the differential amplifier with fixed amplification times. The method is simple and easy to implement, the output signal is amplified to a certain degree on the basis of the original amplitude, the output signal is fixed to the frequency through switching of the fixed frequency, and therefore interference of noise on the signal can be effectively eliminated through subsequent phase-locked amplification detection.

The invention discloses a method for synthesizing a nickel diselenide nanocrystal in a polyalcohol-base solution, which comprises the following steps: (1) weighing 0.25mmol of nickel nitrate hexahydrate, and dissolving in 10ml of triethylene glycol to obtain a nickel precursor cation source solution; adding 40ml of triethylene glycol into a three-neck round-bottom flask, adding selenium powder, and adding 0.1g of polyvinylpyrrolidone to obtain an anion source solution, wherein the Ni / Se mol ratio is respectively 1:2, 1:1.9, 1:1.8 and 1:1.7; and (2) slowly heating the anion solution to 210-270 DEG C while quickly injecting the cation source solution, and reacting under reflux to synthesize the NiSe2 nanocrystal solution. The method has the advantages mild whole reaction conditions, high safety, low toxicity, low cost, single and stable product phase and favorable repetitiveness, and is simple to operate, and the stoichiometric proportion and material feeding have favorable consistency.

The invention relates to a method for reducing plucking oscillations of a friction clutch that is automatically controlled by a clutch actor on the basis of a target clutch torque which is associated to a clutch torque to be transmitted, wherein the friction clutch is arranged in the drive train of a motor vehicle between an internal combustion engine and a gear and has an oscillation clutch actual torque as a result of temporary plucking oscillations. In order to achieve a reduction of the plucking oscillations, an absolute amplitude and a phase of the input signal is determined from an input signal that is representative for the oscillating clutch torque on the basis of an oscillation selective reference variable derived in a torque path between internal combustion engine and friction clutch, on the basis of a transmission function reproducing the reference value to an oscillation selective clutch torque, from which phase selective clutch disturbance torque an in-phase clutch correction torque is determined, and by means of said in-phase clutch correction torque the desired clutch torque is corrected.

The invention discloses a coherent laser radar for improving detection range by adopting an optical phase-lock technology. The coherent laser radar comprises a main laser device (space coupling), a tunable local oscillator laser, a receiving optical system, a 3dB coupler, a balanced detector, a frequency and phase discrimination module (PFD), a charge pump and a loop filter. A beat frequency signal is obtained after the laser emitted by the main laser device is interfered by an echo signal reflected by a target and local oscillator light, phase difference of two signals can be obtained after the beat frequency signal and a set reference signal are subjected to the frequency and phase discrimination module, the frequency of the local oscillator laser device is regulated and controlled through the corresponding control voltage produced by the loop filter, so that the beat frequency signal can be locked to the set reference signal phase, the beat frequency signal meets a condition of timedomain coherent accumulation, the extraction of the weak signal is more facilitated, and the detection range of the coherent laser radar is finally improved.

The invention discloses a nano sulfur-fixing agent which is prepared from the following components in parts by weight: 4-6 parts of kaolin, 2-5 parts of diatomite, 1-3 parts of diopside, 4-7 parts of cordierite, 1-3 parts of talcum powder, 5-8 parts of calcium oxide, 3-6 parts of iron oxide, 2-5 parts of zinc oxide, 0.3-0.6 part of calcium peroxide, 3-5 parts of strontium carbonate, 2-6 parts of barium hydroxide, 0.3-0.5 part of potassium sulfate, 0.2-0.6 part of vanadium pentoxide, 6-8 parts of niobium pentaoxide, 1-3 parts of sodium ferrate, 0.4-0.8 part of sodium citrate, 20-25 parts of ethanol, 4-7 parts of nano titanium dioxide, 5-8 parts of nano calcium carbonate and 1-3 parts of nano aluminum oxide. The sulfur-fixing agent disclosed by the invention has the advantages of reasonable formula, high temperature resistance and favorable high-temperature sulfur-fixing effect, and thus, has favorable development prospects in the aspect of sulfur fixation of coal.

The invention provides a new method for generating arbitrary waveforms on the basis of optical injection locking, which adopts the optical injection locking technology to keep multiple channels of optical signals stable relatively so as to generate arbitrary waveforms according to different harmonic components which are composed of difference frequencies of the optical signals. A wide-band light source is injected into multiple distributed feedback semiconductor lasers through an optical isolator and a series of beam splitter prisms sequentially, and mode locking is realized after working temperature and current of each laser are regulated. Phase and amplitude of output optical signals of the lasers are changed respectively by regulating the spatial positions of the lasers and dimmable power attenuators in output optical paths. Different channels of difference-frequency signals with adjusted phase and amplitude are coupled through the optical paths, so that arbitrary waveforms are generated finally. The method can be used for generation of arbitrary waveforms in the frequency ranging from several Ghz to dozens of Ghz, and can be applied to multiple fields of manufacturing of ultrahigh signal generation equipment, testing of communicating systems, radar communication and the like widely.

The invention discloses novel safety emulsion for medical and food grade spunlace nonwoven. Ethylene and vinyl acetate serve as monomers, suitable non-ionic emulsifiers and cationic emulsifiers are screened, and the emulsion is prepared by a pressurized copolymerization process, non-toxic and harmless, and stable in phase. Preservation time of the emulsion is as long as 24 months, the solid content ratio of the emulsion reaches more than 53%, the emulsion has fine hydrophilic performance and excellent washing and chemical resistance, can be blended with other strongly cationic components (such as methyl guanidine and metformin), ensures antibacterial capability and has excellent bonding strength with cellulose fibers such as cotton and viscose. The novel safety emulsion for the medical and food grade spunlace nonwoven has the advantages that cohesive force and binding force between regenerated fibers can be effectively improved, the physical performance of a product is enhanced, picking and dusting in the use process of the product are decreased, the service life or frequency of the product is prolonged, the product is durable and resistant to washing while fine water absorption capability is kept, and the emulsion can be compatibly used with the vast majority of cationic antibacterial agents.

The invention discloses a high heat conductivity aluminum-diamond diphase continuous composite material preparation method which includes that: diamond particles and aluminum are regularly arranged to lead the diamond particles to be in a continuous contact state in heat conduction direction; the arranged blanks receive densification treatment; and the blanks after densification treatment are sintered. The densification treatment includes cold isostatic pressing, flexible mold pressing, steel mold pressing, rolling and squeezing. The sintering treatment includes protective atmosphere sintering, vacuum sintering, hot pressing, hot isostatic pressing and spark plasma sintering. The invention has advantages that: the composite material prepared by the preparation method has higher density, uniform structure, stable phase and high heat conductivity. The coefficient of heat conductivity in diamond continuous contact direction is three times of the coefficients in other directions. The invention initiatively adopts aluminum and diamond to prepare diphase continuous composite material, reduces the cost and improves the performance of heat conductive material. The invention not only brings innovative significance to prepare heat conductive materials, but also promotes the theory and practice in the composite material field.

The invention relates to a method for preparing foamed ceramic from metallurgical high-temperature flow-state steel slag, and belongs to the technical field of building materials. According to the method, the waste steel slag serves as a main raw material, physical heat in the metallurgical production process is utilized, the steel slag does not need to be sintered after being subjected to the processes of cooling, crushing, mixing and the like, and thus the remarkable energy-saving and consumption-reducing effects are achieved in the product preparation process. In addition, the steel slag at the temperature of 1100-1400 DEG C in the steelmaking process is directly used in the high-temperature molten state without supercooling, and the steel slag does not need to be treated by a water splashing method or a hot stuffy method so that evaporation of hot fugitive white water vapor is completely eliminated, the environment is improved, and the environment-friendly'white removal 'requirement is met. The foamed ceramic prepared by the method is stable in phase and uniform in pores, foamed ceramic parts with different complex shapes can be manufactured according to different requirementsof product usability, and the foamed ceramic has good social benefits and economic benefits and wide application prospects.

The invention discloses a high-speed laser cladding alloy powder for surface strengthening of a centrifugal compressor and a method thereof, and develops a laser cladding alloy powder suitable for improving erosion resistance and cavitation resistance of a substrate and a corresponding high-speed laser cladding process. The alloy powder comprises the following raw materials of, in percentage by mass, Co, nickel-coated WC, Cr, Ti and other components. According to the method, the wettability between a cladding layer and the substrate is improved by adopting elements of the Co, the Cr and the Ti, the metallurgical bonding strength between the cladding layer and the substrate is improved, the cracking sensitivity in erosion and cavitation processes is reduced, and the oxidation resistance ofthe cladding layer is improved; a temperature field is reasonably controlled by adjusting the particle size, the proportion and the laser parameters of the alloy powder, so that the dilution rate is reduced, and the thermal stress at an interface is reduced; and compared with a substrate, the anti-erosion performance is improved by 3-4 times, and the cavitation resistance is improved by 2-3 times.

A sol-gel preparation method of a strontium titanate lead thin film is high in tunability and uses tetrabutyl titanate, lead acetate trihydrate and strontium atetate as raw materials and ethylene glycol monomethyl ether and acetic acid as solvents to prepare a strontium titanate lead sol precursor. A thin film is prepared on a substrate in spinning coating method, annealing treatment is carried out repeatedly to obtain a strontium titanate lead ferroelectric thin film. The prepared strontium titanate lead thin film is compact, uniform in granularity and better in quality, has no unclear second phase and has high tunability, the whole process is simple, the period is relatively short, time and cost are saved, and the sol-gel preparation method can manufacture the strontium titanate lead thin film with high performance and has good market application prospect.

An embodiment of the invention relates to an environment-friendly waterborne block copolymer dispersant and a preparation method thereof. The environment-friendly waterborne block copolymer dispersantis made from, by mass, 20-30% of a polymerization monomer, 5-10% of cyclic alkyl sultone, 5-10% of a long-chain alkyl monomer, 1-3% of polysiloxane, 1-3% of an initiator, 0.5-1% of an activator, 2-5%of a chain transfer agent, 1-3% of waterborne RAFT (reversible addition-fragmentation chain transfer polymerization) agent, 1-2% of a neutralizer, and 45-55% of deionized water. The environment-friendly waterborne block copolymer dispersant provided by an embodiment of the invention has the special structure block copolymer and allows characteristics of different homopolymers to be integrated, amorphism and elasticity of flexible block and crystallinity and rigidity of rigid block help pigment-filler and mineral powdery particles to dispersedly suspend in the solutions, such as a paint base,for long time, macroscopic separation can be prevented, secondary flocculation is avoided, and a prepared colored paint system has good storage stability and brighter color that lasts for long time.

The invention discloses a novel sulphur-fixing agent. The novel sulphur-fixing agent is prepared from, by weight, 2-5 parts of kaolin, 3-6 parts of bentonite, 4-8 parts of zeolite, 5-8 parts of kieselguhr, 2-4 parts of perlite, 10-15 parts of cordierite, 1-3 parts of talcum powder, 6-8 parts of calcium oxide, 4-8 parts of ferric oxide, 3-5 parts of zinc oxide, 0.2-0.4 part of calcium peroxide, 6-8 parts of strontium carbonate, 4-7 parts of barium hydroxide, 0.2-0.5 part of potassium sulphate, 0.3-0.7 part of vanadium pentoxide, 6-9 parts of niobium pentoxide, 0.1-0.3 part of aluminum powder, 20-25 parts of ethyl alcohol, 5-9 parts of nanometer titania and 6-8 parts of nano calcium carbonate. The novel sulphur-fixing agent is reasonable in formula, resistant to high temperature and good in high-temperature sulphur-fixing effect, and has good development prospects on the aspect of coal sulphur fixing.

The invention discloses a few-layer graphene modified oxygen vacancy stannic oxide material and a preparation method thereof. The preparation method comprises the steps that stannic oxide hollow nanosphere powder uniform in size and good in dispersion and graphene oxide with few-layer characteristics and high uniformity are prepared, and the surface of the stannic oxide is coated with the grapheneoxide; by means of surface graphene, sodium borohydride and subsequent vacuum heat treatment, a large number of oxygen vacancies are successfully manufactured in the stannic oxide hollow nanospheres,and the oxygen vacancy SnO2@rGO composite material is obtained. The method disclosed by the invention is simple to operate and can be put into production on a large scale, and the obtained compositematerial has very high sensitivity and cycling stability to reducing gas and can be used as a positive electrode material of a supercapacitor.

The invention discloses a PBT / ABS (polybutylene terephthalate / acrylonitrile-butadiene-styrene) alloy material and a preparation method thereof. The PBT / ABS alloy material comprises the following components in percentage by mass: 20-40% of PBT, 70-50% of ABS, 2-8% of MAG, 0.2-3% of a lubricant and 0.2-0.5% of an antioxidant. The PBT / ABS alloy material disclosed by the invention has the beneficial effects that MGE (methyl methacrylate-glycidyl methacrylate-ethyl acrylate) is added to perform reactive compatibilization and blending compatibilization on the PBT / ABS alloy material to ensure that the performance of the PBT / ABS alloy material is effectively improved, system phases are dispersed more uniformly, and the phase morphology is more stable to obtain more benefits for molding processing, then the PBT / ABS alloy material has the characteristics of both PBT and ABS, the ABS has the function of improving the impact strength of PBT, the PBT has the function of better improving the processability and chemical reagent resistance of the ABS at the same time, so that the PBT / ABS alloy material has the characteristics of stable size, high strength, good appearance, high chemical reagent resistance and the like.

This invention discloses a method for precisely shifting phases and a phase-shifter, first of all, which cuts a HF input signal in a counter, which outputs a low frequency square wave signal to be shifted, secondly outputs a two double frequency square wave signal of the being shifted signal, thirdly switches the HF input signal and the two double frequency square wave signal in a preset counter to output a phase-shift square wave labeling square wave and fourthly switches the shift labeling square wave and the low frequency signal to be shifted in a trigger to output the shifted low frequency square wave to finish the phase shift. Device realizing said method include a counter and preset counter and a trigger.