279 results about "Middle frequency" patented technology

The invention relates to a self-lubricant composite soft coat blade, and relative production. Wherein, said blade uses the MoS2 / Zr / Ti composite coat blade made from middle-frequency magnetic-control multi-arc plating method; the surface of blade is MoS2 layer, between which can base there are Ti, MoS2 / Zr / Ti, and MoS2 / Zr transition layer; when using said blade to cut, the surface of blade can form continuous lubricant layer, to realize self-lubricant function; since the solid lubricant has low shearing strength, the solid lubricant layer will be transferred to the surface of work piece, to form transfer film and the friction in the cutting process will generate inside the solid lubricant layer, to reduce friction, reduce shearing force and reduce shearing temperature.

The invention relates to a heterodyne three-frequency unequal range phase displacement solution phase method, and the method is as follows: selecting three frequencies, firstly adopting four-step phase shift method to obtain the package phase and average light intensity of the middle frequency, adopting two-step phase shift method to obtain the package phase corresponding to the two frequencies under the condition with known light intensity, obtaining the true phase according to the heterodyne method, adopting the contour line sine and cosine filtering method in the optical grating projection three-dimensional measurement, using stripe direction information for filtering the package phase on isophasal line, the method uses less projection picture for exactly measuring and uses the stripe direction information for filtering the package phase picture for effectively removing the inconsistent points in the package phase picture, the heterodyne three-frequency unequal range phase displacement solution phase method is used in the phase method three-dimensional shape measurement for effectively raising the measuring efficiency and measuring accuracy.

The invention relates to a high-performance silver cadmium oxide material and a manufacturing method thereof, which are characterized in that the silver cadmium oxide material comprises the following components: 85 to 97 percent of silver, 2 to 15 percent of cadmium, 0.01 to 0.5 percent of nickel, 0.01 to 1 percent of tin and 0.01 to 0.5 percent of rear earth mixture. The manufacturing method of the high-performance silver cadmium oxide material is characterized in that: a given quantity of silver, cadmium, nickel, tin and rare earth mixture are measured to be arranged inside a middle-frequency induction furnace to be smelted and cast, the cast ingot is extruded by an extruding machine to be thick wires, the thick wires are stretched by a wire-drawing die to be thin wires, the thin wires are pre-oxidized by an internal oxidization furnace, then the thin wires are cut and preformed and finally is processed and formed. The anti-oxidization performance, electric-arc burning loss resistance and the abrasion resistance of the silver cadmium oxide material are improved, and the service life is prolonged, so the high-performance silver cadmium oxide material can be applied to different working environments, has low production cost, simple manufacturing method and low requirements on the device and the production.

The invention discloses a method for predicting wind speed and power of a wind farm based on wavelet decomposition and a support vector machine. The method comprises: acquiring wind speed and power historical data of a whole wind farm in a preset time, to obtain a historical wind speed time sequence and a historical power time sequence of the wind farm; using a wavelet packet decomposition technology to perform wavelet packet decomposition on the historical wind speed time sequence, to obtain a low-frequency stage component, a middle-frequency stage component, and a high -frequency stage component of the historical wind speed time sequence; using a grey support vector machine prediction model to predict each component of the historical wind speed time sequence, and then using wavelet packet reconstruction to obtain short-period wind speed prediction data; using historical wind electricity power data and numerical weather prediction wind speed data as a training set to establish a grey support vector machine model, predicting wind electricity power; predicting the obtained wind speed prediction data and the wind electricity power prediction data through a RBF neural network, to obtain a final prediction value of the wind electricity power.

The invention relates to a casting method and casting machine of the induction motor cooper squirrel-cage rotor, which is suitable for the casting of pure copper and high copper content alloy. The invention belongs to nonferrous metal smelting and rolling process technology filed. The casting method comprises module pre-process, copper smelting, liquid casting and forming and quench water cooling. The casting method adopts a casting device which is composed of a casting machine and a smelting furnace, wherein, the smelting furnace comprises an integrated pot and middle frequency induction furnace, the heating efficiency of the middle frequency induction furnace is 0 to 100KW; the casting module comprises a group connection which is connected by a plurality of embedded lump. The invention has reasonable technics and equipment, the product has no defects of breakage on casting piece and surface, poor filling and mold sticking, the shaking present value complies with the R degree provision in IEC34-14(1994), which has the advantages of improving by one degree comparing with the N degree stipulated in Y series motor technology condition.

The invention discloses a Cr series high-temperature solar selective absorbing coating and a preparation method thereof. The coating consists of an infrared reflection layer, an absorption layer and an antireflection layer in turn from the bottom to the surface, wherein the first infrared reflection layer consists of three membranes; the middle infrared reflection layer is a Ag membrane of which the upside and downside are plated with a protective film that is any one of a chromic oxide (Cr2O3) film and an aluminum oxide (Al2O3) film respectively; the second absorption layer has two sub-layer structures both of the which are AlCrN+AlCr films, the volume percentage of the first sub-layer AlCr is greater than that of the second sub-layer AlCr; and the third antireflection layer is any one of Cr2O3 film and Al2O3 film. The preparation method comprises the steps of: preparing the infrared emission layer on the substrate surface by adopting a pure metal target magnetron sputtering process; preparing the second absorption layer on the first layer by adopting a Cr target and Al target middle-frequency magnetron sputtering process; and preparing the third antireflection layer on the second layer by adopting a metal target middle-frequency magnetron sputtering process.

The invention belongs to a heat processing technique of 42CrMoE material used for a reciprocating compressor. The technique is suitable for the heat processing technique for the 42CrMoE piston rods used for all the reciprocating compressors and can also be applied to the mechanical devices which require high rigidity, wear resistance and corrosion resistance. The invention can solve the problems of cracks, low surface hardening rigidity as well as poor wear resistance, poor acid resistance and poor corrosion resistance generated when the traditional surface heating processing technique is applied to the 42CrMoE piston rod, and the like. The invention includes the forging and shaping, hardening and tempering, stabilizing, nitriding, middle frequency or high frequency quenching as well as low temperature annealing of the 42CrMoE material; a surface compounded heat processing technology combined with nitriding and middle frequency or high frequency quenching is adopted: the 42CrMoE material is arranged in a nitriding furnace; ammonia gas is pumped in after the treatments of temperature rising and pro-oxidation to carry out nitriding treatment; then the middle frequency or high frequency quenching on the surface is carried out. The heat processing technique can be adopted to completely prevent the quenching cracks generated during the traditional high frequency quenching, improve the surface rigidity to be more than HRC60, improve the wear resistance by 34 percent and improve the acid and corrosion resistance by 40 percent.

An omnidirectional speaker comprises a high frequency driver which generates sound over a high frequency range and has a first diameter, and a high frequency waveguide having a second diameter which is larger than the first diameter. A first midrange driver has a third diameter and a second midrange driver has a fourth diameter. Each midrange driver generates sound over a middle frequency range and the first midrange driver faces the second midrange driver. A first midrange waveguide corresponds to the first midrange driver and has a fifth diameter, and a second midrange waveguide corresponds to the second midrange driver and has a sixth diameter. The fifth diameter is larger than the third diameter and the sixth diameter is larger than the fourth diameter, and both of the midrange frequency waveguides are positioned between the first midrange driver and the second midrange driver so as to block a direct path from the first midrange driver to the second midrange driver.

The invention discloses a double-channel radar echo simulator as well as a method and a system for generating a double-channel radar echo signal. In the double-channel radar echo simulator, a frequency integrator is used for supplying a clock signal; a field programmable gate array (FPGA) control circuit transmits a control signal to a first digital display scope (DDS) and a second DDS; the first DDS and the second DDS respectively receive the control signal transmitted by the FPGA control circuit and respectively output a first middle-frequency signal and a second middle-frequency signal to a first upper frequency converter and a second upper frequency converter; the first upper frequency converter performs upper frequency conversion on the first middle-frequency signal to obtain a first radio frequency signal; the second upper frequency converter performs upper frequency conversion on the second middle-frequency signal to obtain a second radio frequency signal; and a power distributing network receives the first radio frequency signal and the second radio frequency signal and decomposes the first radio frequency and the second radio frequency signal. By setting two signal processing paths, different delayed interference specific absorption rate (SAR) echo signals are generated according to the variation of a distance between a radar and a measured target.

A printed circuit board (PCB)-printed antenna for a radio frequency (RF) front end with an antenna port for a predefined operating frequency band. A radiating element with a first branch defined by a first set of dimensions corresponding to a minimum frequency and a second branch defined by a second set of dimensions corresponding to a maximum frequency is fixed to a PCB substrate. A third branch is defined by a third set of dimensions corresponding to a middle frequency in various embodiments. A feed line is electrically connected to the radiating element and defines a feed port that is connectable to the antenna port. A ground line is electrically connected to the radiating element and defines a ground port. The first branch defines a first resonance, the second branch defines a second resonance, and the third branch defines a third resonance, all of which are superposed to define a bandwidth of the radiating element that is substantially equivalent to the predefined operating frequency band of the RF front end.

The invention relates to an energy management system of a hybrid power ship based on wavelet-fuzzy logic and a control method. The core of the energy management control method is a wavelet-fuzzy logic algorithm. A power demand is decomposed to power in bands of high, medium and low frequency by means of a wavelet transform method after parameters such as the current power demand of the ship, the state-of-charge of a storage battery and the state-of-charge of a supercapacitor by means of a sensor are acquired. The power of low frequency band is taken as initial output reference power of a fuel cell, the power of middle frequency band is taken as an initial reference power demand of the storage battery and the high frequency band of power is taken as an initial reference power demand of the supercapacitor. The system provided by the invention comprehensively coordinates power flows among different energy sources, that is, electric power demands of the ship shall be reasonably distributed according to dynamic characteristics of FC, the storage battery and the supercapacitor, so that the integral performance of the system is promoted and the economical benefit of fuel is improved.

The invention relates to a high-liner rigid alloy compound roll collar, which comprises a base and a compound working layer whose material brand is different to the base while they are sintered into one whole. The producing method comprises: filling the base and the rigid alloy powder of non-doping molding agent into graphite mould; via vibration, they are filled into special middle-frequency hydraulic vibrating sintering device to be thermally compressed and sintered; and processing second positive pressure sintering; checking the quality and grinding to attain the final product. The invention can improve the rigidity of working layer and the friction resistance; improve the rolling amount of roll collar and the service life, while the waste roll collar can be recycled to save metallic resource. It can apply the finisher of high-speed producing line whose rolling speed reaches 100m / s.

The invention discloses an active ventilated and soundproof window, which comprises a soundproof window. The source ventilated and soundproof window is characterized in that: the soundproof window is provided with an active soundproof ventilation device which comprises a ventilation channel which is communicated with the indoor and the outdoor and an active noise control system. In the invention, the conventional ventilated and soundproof window is provided with the active soundproof ventilation device, and low-frequency noises are counteracted and absorbed by using active noise control technology; and meanwhile, a sound-absorption layer consisting of sound-absorbing materials is coated on the inner wall of the ventilation channel and high and middle-frequency noises are absorbed by a sound-absorbing structure in the ventilation channel. Thus, the low-frequency and high-frequency noises can be effectively reduced under the condition of maintaining high ventilation performance.

The invention relates to an electrical resistance alloys that is made up from 18.0-22.0wt% Ni, 24.0-26.0wt% Cr, 1.5-2.5% wt Si, 0.01-0.08wt% C, 1.00-2.00wt% Mn, 0-0.05wt% Al, 0.08-0.20wt% Re, and the rest is Fe. The making technology includes the following steps: middle frequency smelting, electroslag remelting, hammering, hot rolling, annealing heat treatment, acid wasing, polishing and shaving, coiling jointing, cold rolling, stripping and molding. The method could sharply decrease the content of Ni, and adjust the content of the other alloy constituents that could low producing cost and save energy.

This invention relates to a tube plate and tube connection method of tube shell and tube pad heat exchanger in each energies systems, which comprises the following steps: 1, pre-setting solder ring to the pre-set hole in the tube plate; 2, coating proper solder dose on the tube connection part; 3, putting the tube plate and inside tube onto the workbench of the middle frequency inducing solder welding machine bed and using PLC elements to control the workbench two coordinates accurate movement and heating the tube plate and tube parts till the dose is melted to fill the welding gaps; 4, automatically spray the cold water onto the machine bed to remove the solder dose.

An omnidirectional speaker having a high frequency driver, which generates sound over a high frequency range and which has a first diameter, and a high frequency waveguide having a second diameter larger than the first diameter. A first midrange driver and a second midrange driver have a third diameter and a fourth diameter, respectively. Each midrange driver generates sound over a middle frequency range and the first midrange driver faces the second midrange driver. First and second midrange waveguides have a fifth diameter and a sixth diameter, respectively, and correspond to the first and second midrange drivers, respectively. The fifth diameter is larger than the third diameter and the sixth diameter is larger than the fourth diameter. Both of the midrange frequency waveguides are positioned between the first midrange driver and the second midrange driver so as to block a direct path from the first midrange driver to the second midrange driver.

The invention relates to a wideband sound absorption structure combing mechanical impedance of composite resonance cavities with micropunch plates, and belongs to the technical field of environmental noise control. The wideband sound absorption structure comprises one or more layers of micropunch plates in the front of the structure and a mechanical impedance plate at the rear part of the structure, wherein the micropunch plates and the mechanical impedance plate are all fixed on a bracket; the mechanical impedance plate is formed by an elastically supported thin plate; Helmholtz resonance cavities are compositely arranged on the mechanical impedance plate; each Helmholtz resonance cavity consists of a cavity body and an insertion tube. According to the wideband sound absorption structure, Helmholtz resonance units are designed on the mechanical impedance plate, and the thicknesses of the resonance cavities are smaller, thus the whole structural thickness does not change too much. The micropunch plates can have good sound absorption effect for middle-frequency and high-frequency noises, and a plurality of absorption peaks can be generated at low frequency through a mechanical impedance unit and the Helmholtz resonance units, so that the whole structure can ensure good middle-frequency and high-frequency sound absorption performance and also has good sound absorption effect at low frequency.

A cancer treatment equipment includes a case (7), a squeeze-type friction head (1) connected to direct current, a stiction friction head (2) of low-middle frequency current, a friction head (3) with magnetic sheet, a medicated gauze pad fixation clamp (4), a medicated gauze pad (5) and a treatment device of RF, microwave or ultrasonic. The squeeze-type friction head (1) connected to direct current, the stiction friction head (2) of low-middle frequency current and the friction head (3) with magnetic sheet are fixed in the case (7) in parallel. The medicated gauze pad (5) is fixed on the medicated gauze pad fixation clamp (4) on the lower part of the case (7).

Disclosed herein is a drive device of an electrode channel for strengthening core muscles of an abdominal region, which can improve circulation of body fluid in a body cavity of the abdominal region and activate muscle membrane tissues inside / outside the abdominal cavity. The drive device includes a wearable instrument worn by a user over an abdominal region, a plurality of electrode channels formed by an electrode pair of a positive-terminal strip and a negative-terminal strip provided on the wearable instrument and contacting a body of the user, and a frequency supply unit for generating and selectively applying Russian current having a middle frequency and interference-wave current between the positive-terminal strip and the negative-terminal strip. Control is performed such that Russian current and interference-wave current are selectively applied to a positive-terminal strip of one of the plurality of electrode channels and a negative-terminal strip of another electrode channel.

The invention discloses a disturbance suppression method based on a compound disturbance observer, and aims at the problem that system requirements can not be stably controlled at high accuracy sincethe low-frequency and middle-frequency disturbance suppression capability of a control system stable platform is poor. By use of the method, on the basis of multi-closed-loop control, a traditional disturbance observer design is improved, the compound disturbance observer structure is put forward, and a design method for an inner and outer ring feedforward compensation controller in the compound disturbance observer is given. By use of the method, an outer ring in the compound disturbance observer is utilized for estimation, inverse feedforward of a middle-frequency band and external disturbance, and an inner ring is used for estimation, inverse feedforward of a low-frequency band and external disturbance. The inner ring and the outer ring of the compound disturbance observer simultaneously act, finally, the purposes of simultaneously improving the disturbance suppression capability of the low frequency band and the middle-frequency band of the system and improving and controlling system stability accuracy are achieved.

The invention discloses a method for obtaining a minor fault for seismic tectonic interpretation. The method comprises the steps that (a) spectral analysis is carried out on seismic data so that the spectral range of the seismic data can be obtained; (b) spectral decomposition is carried out through generalized S conversion, the parameters of fractional frequency are determined according to the spectral range obtained in the step (a); (c) high-resolution coherence analysis is carried out on high-frequency fractional frequency seismic data, middle-frequency fractional frequency seismic data and low-frequency fractional frequency seismic data by adopting a coherence method, and the coherence bodies of data bodies of different frequency bands are obtained; (d) fault lines of strata slice interpretation projection are extracted at the corresponding positions on the seismic sections of the fractional frequency seismic data bodies of the corresponding frequency bands, and the extending and spreading conditions of the fault on a time section are interpreted. According to the method for obtaining the minor fault for seismic tectonic interpretation, coherence body fault plane recognition is carried out by adopting a strata slice mode, the situation of loss, caused by tectonic reasons, of minor fault information can be eliminated, and tiny faults can be recognized more easily. The faults are interpreted on the sections of the fractional frequency seismic data bodies of the different frequency bands, the fault information of different scales can be recognized, and the interpretation of the minor fault is facilitated.

The present invention relates to a method for blindly embedding and extracting a watermark by using wavelet transform and a human visual system (HVS) model, which obtains both robustness and invisibility by applying the HVS model of NVF or JND imitating a human visual system to a middle frequency band for wavelet transformation and using a quantization step determined adaptively according to the importance of wavelet coefficient. A method according to the present invention includes the steps of: decomposing an original image by a wavelet and selecting a middle frequency band as a watermark embedment area; obtaining an HVS model having a human visual recognition information at each embedding potion; determining the importance of the coefficient for each embedding potion, and adaptively determining a quantization step for each embedment location by using the importance and the HVS model; quantizing each pair of embedment area by the quantization step and variably embedding a watermark sequence into a middle frequency band according to a value of the watermark; and performing inverse wavelet transform on an overall area into which the watermark sequence is embedded, and generating a watermarked image.

The invention discloses a control method for beat vibration prevention of multi-noise source equipment, and the method is used for controlling a variable frequency air conditioner of multi-noise sources. The method comprises the steps of obtaining total noise value generated by the variable frequency air conditioner and a noise frequency spectrum curve corresponding to the total noise value; analyzing the noise frequency spectrum curve, and determining difference value between an average sound pressure level in a time domain conversion spectrum and peak value in a preset frequency range; determining whether beat vibration noise exists or not according to the difference value; and when the beat vibration noise exists, the beat vibration noise is eliminated by reducing the operating frequency of a compressor or a fan. The invention also discloses a control device for beat vibration prevention of the multi-noise source equipment. According to the control method, whether beat vibration noise exists in a unit or not is determined by difference of the average sound pressure level of the time domain Fourier conversion spectrum and the peak value of the middle frequency and the low frequency, and if the beat vibration noise exists, the beat vibration noise is eliminated by controlling the operating frequency of the compressor or the fan. The control method and the device are simple andreliable, and are easier to popularize and use.

The present invention relates to a method for blindly embedding and extracting a watermark by using wavelet transform and a human visual system (HVS) model, which obtains both robustness and invisibility by applying the HVS model of NVF or JND imitating a human visual system to a middle frequency band for wavelet transformation and using a quantization step determined adaptively according to the importance of wavelet coefficient. A method according to the present invention includes the steps of: decomposing an original image by a wavelet and selecting a middle frequency band as a watermark embedment area; obtaining an HVS model having a human visual recognition information at each embedding position; determining the importance of the coefficient for each embedding position, and adaptively determining a quantization step for each embedment location by using the importance and the HVS model; quantizing each pair of embedment area by the quantization step and variably embedding a watermark sequence into a middle frequency band according to a value of the watermark; and performing inverse wavelet transform on an overall area into which the watermark sequence is embedded, and generating a watermarked image.

Disclosed is an earphone comprising a loudspeaker unit, an audio signal wire electrically connected to the loudspeaker unit, and an auxiliary structure; the auxiliary structure comprises a front cover and a housing; a front acoustic cavity is defined as a space between the front cover and the loudspeaker unit, and a rear acoustic cavity is defined as a space between the housing and the loudspeaker unit; a acoustic guide channel capable of enhancing low-frequency performance of the earphone is disposed on one side of inner sidewall of the housing closer to the loudspeaker unit; the acoustic guide channel comprises an open end and a closed end, and bottom wall of the acoustic guide channel is provided with a plurality of through holes at a position closer to the closed end. Earphone with this structure improves low-frequency and middle-frequency sound effects of products, and makes the earphone has a good appearance.

The invention provides a high-performance capturing method of a wireless long-time cycle spreading code signal of a navigation satellite inter-satellite link. The high-performance capturing method comprises steps of: S1: carrying out orthogonal down conversion on a middle-frequency reception signal; S2: carrying out continuous data buffering on an I / Q signal; S3: carrying out parallel correlator operation on local multi-path spreading code signals after "a segment" of the I / Q signal is fully filled; S4: carrying out coherent accumulation on operation results and then storing the obtained result into "coherent integration buffer"; S5: after the "coherent integration buffer" is fully filled, returning to the step S3, and processing the next segment of the I / Q signal; S6: after the "coherent integration" is finished, carrying out modulo and square operation on the coherent integration results, carrying out incoherent accumulation on the results and then stored the obtained result into the "incoherent integration buffer" until the whole buffer cache is fully filled; and S7: after the "incoherent integration" is finished, carrying out peak value detection on integration detection results representing different phase positions in the incoherent integration buffer and judging whether the capturing is successful or not. According to the invention, resource use rate of time domain capturing can be remarkably increased and requirements on resource storage are greatly reduced.

The invention discloses a broadband microwave signal low-phase noise synthesizing device and method. The device comprises a reference source, a fractional frequency division oscillating circuit, a broadband sampling local oscillating circuit, a sampling frequency mixer, a middle-frequency filter, a phase discriminator, a circuit integrator, a broadband microwave oscillator, a broadband microwave amplifier, an amplifier, a frequency multiplier, a narrowband filter, a high-purity-point frequency synthesizing circuit, a band-pass filter, a broadband filter, a broadband microwave frequency mixer and a low-pass filter. According to the broadband microwave signal low-phase noise synthesizing device and method, the broadband microwave signal low-noise synthesis technology according to which fixed frequency mixing, sampling and frequency mixing are combined, a traditional broadband sampling procedure is improved, namely before sampling on a feedback signal is carried out by a YIG oscillator, the feedback signal is mixed with a highly-pure local oscillation signal with the fixed frequency at first and the frequency of a local oscillation signal is converted from a high frequency into a low frequency. Then the local oscillation signal enters a sampler and undergoes sampling and frequency mixing with a sampling local oscillation signal. Thus, the sampling harmonic number can be reduced, and therefore deterioration of phase noise is relieved.

The invention discloses a hydraulic exciting device, comprising conversion control system, hydraulic pump station and exciting oil cylinder. The hydraulic pump station comprises conversion motor and it also comprises twin pump, vibration pump, oil supply valve, overflow valve, electromagnetic switching valve, back-pressure valve group, low-pressure spindle valve and low-pressure overflow valve, which are connected by hydraulic pipes. The vibration pump adopts crank-shaft mechanism to drive the piston move to and fro in cylinder. A pair of outlets of piston cylinder of vibration pump set symmetrically are connected with cavity with bar and cavity without bar of exciting oil cylinder by hydraulic pipes respectively to constitute the closed loop. Because the invention adopts twin piston vibration pump vibration parameters can be adjusted separately in stepless and energy consumption is low. Single-point excitation or multi-point excitation can be adopted to satisfy the requirement for mining with middle frequency and large amplitude. It is suitable for linear vibration equipment and vibration test-bed. Especially it is suitable for mining, power generating, sugar producing and salt producing so on.

A dieless wire drawing forming device comprises a wire pay-off drum, a wire take-up drum and a platform, wherein the wire pay-off drum is driven by a wire pay-off drum drive motor, the wire take-up drum is driven by a wire take-up drum drive motor, and the shafts of the wire pay-off drum drive motor and the wire take-up drum are respectively supported by the platform through shaft bases. The dieless wire drawing forming device is characterized in that a heater and a cooler are arranged between the wire pay-off drum and the wire take-up drum; the heater is supported on the platform through a bracket; the cooler is supported on the platform through a bracket; the distance S between the heater and the cooler is the width of a deformation region, which is determined by the performance of processed line material; the heater is a high-frequency or a middle-frequency electrical heater; and the cooler is a water cooler or an air cooler. The invention provides a dieless wire drawing processing method with high efficiency, no friction and no lubrication.