63results about How to "Reduce noise energy" patented technology

Described are biaxially oriented polylactic acid (BOPLA) films with a novel formulation that exhibits a softer feel and quieter sound, without jeopardizing film making stability. The films can be used, for example, in packaging applications. The films can be metallized, or combined with barrier coatings or layers, for improved gas barrier properties particularly for moisture vapor transmission barrier desired in packaging applications. The films can also be printing films for packaging applications and may be transparent or matte in appearance. The films have characteristics that are beneficial to converting processes, are economical, and maintain bio-compostability similar to typical BOPLA films.

An air induction silencer assembly includes an acoustic interference member disposed within a conduit. The acoustic interference member is tuned to acoustically cancel a selected noise energy frequency. An acoustic absorbing member is also disposed within the conduit. The acoustic absorbing member converts noise energy within the conduit into heat energy to attenuate noise energy within the air induction silencer assembly. The air induction silencer assembly connects to a flexible conduit that includes an inlet portion, an outlet portion, and a flexible joint that connects the inlet portion and the outlet portion together. The flexible joint includes a rolling lobe and a rolling surface. The rolling lobe moves along the rolling surface when the inlet portion moves relative to the outlet portion.

A magnetic transducer (109) for measuring the flow of a fluid (108) has electrodes (102) and an alternating magnetic field (107), an electrode (102) having lower noise energy at frequencies below 5 Hz than an electrode comprising carbon or corrosion-resistant metal alloy. The noise characteristic of the electrode (102) at magnetic field frequencies around 1 Hz is lower than that of an electrode comprising carbon or corrosion-resistant metal alloy.

The invention discloses a TPLC based power line power frequency communication system, which is characterized in that the system is installed under each transformer area, a master module is installed at a concentrator, and a slave module is installed at each terminal meter; the master module is provided with an inbound signal detection circuit, an outbound signal modulation circuit and a processor; each slave module is provided with an inbound signal modulation circuit, an outbound signal demodulation circuit and a processor; and the concentrator sends outbound signals to the slave modules through the master module and detects inbound signals sent by the slave modules, and each terminal meter sends the inbound signals to the master module through the slave module and detects the outbound signals sent by the master module. According to the invention, the modulated pulse signal frequency is far lower than the conventional power carrier signal frequency, the system is not susceptible to influences of impedance of a power distribution network, low-frequency signals are not attenuated, the transmission distance is greatly increased, power grid noise energy in a corresponding frequency band is small, the communication success rate is much higher than that of a traditional carrier communication method, point-to-point communication is used directly, networking is not required, and network topology is simple.

A synchronized controlled oscillation modulator (SCOM), comprising at least one, Controlled Oscillation Modulator (5), and synchronizing means (1, 6) connected to said COM modulator. The modulator can comprise several COM modulators, and the synchronizing means can be arranged between the COM systems, so that the oscillation modulator signal is used as synchronization signal. The invention provides significant advantages in performance, topological simplification, improved robustness, stability and efficiency compared to prior art.

The embodiment of the invention discloses a low-signal-to-noise-ratio complex radar pulse envelope signal detection method and device. The device includes a digital channelization module, a signal envelope extraction module, a channel number-based envelope correction module and a double-threshold pulse detection module. First an input radar signal is subjected to channelization processing, and noise outside a channel is filtered; then a multipath channel signal envelope is extracted; then the signal envelope is corrected; and finally, a double-threshold pulse detection algorithm is adopted to ensure that a complete complex radar pulse signal is detected.

The invention discloses a regenerated rubber matrix based combined damping plate and a manufacturing method. The regenerated rubber matrix based combined damping plate comprises a bottom layer and a damping layer, wherein the bottom layer is a steel plate; the damping layer is manufactured from modified regenerated rubber; if only one surface of the modified regenerated rubber is adhered to the steel plate, the steel plate and the regenerated rubber can form a free damping layer structure; if both surfaces of the modified regenerated rubber are adhered to the steel plate, two steel plates and the regenerated rubber can form a constraining damping layer structure; the two steel plates are different in thickness in order to avoid coincident effect within the same frequency range. The regenerated rubber matrix based combined damping plate is simple in structure; the high sound insulation effect of the steel plate is comprehensively utilized and the modified regenerated rubber material is adopted to form a large-damping constraining structural layer for inhibiting the easy-resonating performance of the steel plates, and therefore, the energy of the noise transmitting through the sound insulation plate can be reduced by more than 90%; the regenerated rubber used as the damping material can reduce the material cost of the damping plate and can also greatly reduce the pollution of the waste rubber to the environment.

A magnetic transducer (109) for measuring the flow of a fluid (108) has electrodes (102) and an alternating magnetic field (107), an electrode (102) having lower noise energy at frequencies below 5 Hz than an electrode comprising carbon or corrosion-resistant metal alloy. The noise characteristic of the electrode (102) at magnetic field frequencies around 1 Hz is lower than that of an electrode comprising carbon or corrosion-resistant metal alloy.

The invention discloses an automatic gain control method and an automatic gain control device, which are used for controlling a gain value of a received signal. The method comprises the following step of: at the same time of regulating and converging the gain value, entering a searching mode to additionally change the gain value at least once to make the gain value approximate to a target level according to at least one characteristic value of relation indicating the change of the gain value with time. In another embodiment, the method further comprises the step of: entering a tracking mode to make the regulation period of gain longer than that before in a periodical gain regulation way so as to reduce introduced noise energy in the tracking of signal strength. Therefore, the embodiment of the invention can improve gain convergence speed, further reduce the influence of noises to a communication system in a mobile receiving environment and improve signal receiving efficiency.

The invention discloses a noise reduction structure of a motor of a vacuum cleaner, which comprises a motor inner cover and a motor outer cover surrounding the motor. The noise reduction structure is characterized in that the lateral wall of the motor inner cover is provided with at least one sound deadening chamber. Compared with the prior art, because the lateral wall of the motor inner cover is provided with at least one sound deadening chamber which plays a good role in sound insulation and noise elimination, the noise reduction effect of the noise reduction structure of the motor of the vacuum cleaner is greatly enhanced.

The invention discloses a fan used for a range hood and a range hood with the fan. The fan comprises a volute and a volute tongue, wherein the volute comprises a front plate, a rear plate, a coaming and a volute flange, the front plate and the rear plate are arranged in parallel in the front-and-back direction, the coaming is connected between the front plate and the rear plate, an opening is formed in the top of the coaming, and the volute flange is connected to the top of the front plate, the top of the rear plate and the top of the coaming and provided with an air outlet communicated with the opening; the volute tongue is arranged close to the air outlet, a noise attenuation space is formed by the volute tongue and at least one of the front plate, the rear plate, the coaming and the volute flange together in a defined mode, and a plurality of through holes are formed in the volute tongue. According to the fan used for the range hood, air is compressed in the sound attenuation space by effectively using sound waves and rubs with the inner walls of the through holes in the volute tongue, and the noise energy is consumed, so that noise is lowered, and noise pollution is reduced.

A spread spectrum clock generating apparatus is disclosed. The spread spectrum clock generating apparatus includes a phase lock loop module and a spread spectrum module. The phase lock loop module is used for dynamically tuning frequency of an output clock. The spread spectrum module includes a counter, a plurality of delta-sigma counters and a data shifter. These delta-sigma counters accumulate input signals, and enable a first overflow signal while accumulation of a last stage delta-sigma counter is overflowed. The frequency of the output clock can be tuned dynamically according to the first overflow signal, and the spectrum of the output clock can be spread.

The invention provides an EMD (Empirical Mode Decomposition) based normalization bistable stochastic resonance weak signal detection under oversampling and belongs to the field of signal processing technology. According to the invention, EMD and normalization stochastic resonance are combined into a new system. Signal mode component is superposed for parameter normalization on the basis of EMD ofnoisy signals, so that noisy signals are enabled to meet requirements for stochastic resonance small parameters and are sent to a stochastic resonance system. Whether obvious peaks exist or not is observed through observing a spectrogram and the average SNR gain is calculated. The SNR increases to some extent after EMD and increases once more after stochastic resonance. The total increase is greater than that of using stochastic resonance independently. The EMD based normalization bistable stochastic resonance weak signal detection under oversampling disclosed by the invention has universal meaning in practical application, reduces parameter adjustment complexity and solves a problem that large frequency cannot meet requirements for stochastic resonance.

Automatic gain control method and apparatus control a gain of a received signal. While the gain is adjusted and thus converges, a finding mode is entered to additionally change the gain at least once according to at least one characteristic value obtained from a relationship between the gain and time, such that the gain approaches a target level. In other embodiments, a tracking mode is further entered to periodically adjust the gain at a period greater than that before when signal strength is being tracked to reduce noise energy introduced. Hence, the embodiments can improve a gain converging speed and reduce the influence of the noise on the communication system in a dynamic receiving environment, and thus enhance the signal receiving performance.

A lubricating oil additive based on the libricating mechanism of cermet is prepared from mineral oil, alkali-earth metal sulfonate, polyboroamine, atoleine, zinc dialkyldithiophosphate, molybdenum dialkyldithiophosphate and arene solvent. It can be converted to chemical-bond ceramic structure of molybdenum phosphate and boron nitride in friction part, resulting in reducing wear and temp of engine, increasing efficiency of fuel oil, and decreasing tail gas exhaust and noise.

The system comprises an amplifier, a mixer and a limiting circuit. Said amplifier makes pre-amplification for the received RF analog signals. Said mixer converts the amplified RF analog signals and LO signal to intermediate frequency analog signals through a nonlinear transform. Said limiting circuit is connected to the amplifier and the mixer in series to limit the interference signal level higher than desired signal. The invention can provide anti-interference process for both analog demodulation system and digital demodulation system.

The invention provides a water absorption silencer which is used in various engines. The water absorption silencer comprises an outer cavity, at least one sound attenuation floating cavity, an air inlet pipe and an exhaust pipe, wherein the air inlet pipe and the exhaust pipe are arranged at two sides of the outer cavity, sound attenuation cotton covers the inner surfaces of the sound attenuation floating cavities, and the sound attenuation floating cavities are communicated with the air inlet pipe and the exhaust pipe after serially connected; and water bodies are filled between the sound attenuation floating cavities and the outer cavity. The water absorption silencer can ensure that noise flow enters inside and then is rapidly weakened in noise energy, and has better sound attenuation on various frequencies of noise.

The invention relates to an efficient noise-reducing distribution box which comprises a distribution box main body, wherein an efficient noise-reducing device is arranged in the distribution box main body; the efficient noise-reducing device comprises a foaming latex shell and a foaming latex plate; the foaming latex plate is arranged on one side of the foaming latex shell; the other side of the foaming latex shell is matched with an inner wall of the distribution box main body; and a plurality of silencing slots are formed in the foaming latex plate. According to the invention, an efficient noise-reducing plate, a magnet and chloroprene rubber are combined; the efficient noise-reducing plate is magnetic; and when noise passes by the efficient noise-reducing plate, the efficient noise-reducing plate deforms and is capable of absorbing the noise energy, and meanwhile, the magnet arranged on the chloroprene rubber is capable of buffering the deformation of the efficient noise-reducing plate under the effect of magnetic force, so that the absorbing efficiency of the efficient noise-reducing plate for the noise can be increased and the noise-reducing effect can be promoted.

The invention discloses a method for improving a signal-to-interference ratio of a phase coded signal, and belongs to the field of signal processing. The method comprises: in a first step, carrying out speed separation and compensation to solve pulse pressure primary-to-secondary ratio loss caused by target speeds, wherein the target speeds can correspond to Doppler frequency shifts, i.e., acquiring and storing data of units at the same distance in N adjacent transmission periods and carrying out N-point FFT calculation to obtain N pieces of channel data so as to separate different speed targets into different channels, and carrying out Doppler compensation on each channel, wherein a compensation value of an nth path is n*fr / N+m*fr, fr represents a transmission pulse repetition frequency and m represents folding times by which a target Doppler frequency corresponds to fr; in a second step, carrying out channel noise reduction to solve signal-to-interference ratio loss caused by noise,i.e., designing a high-stopband suppression filter so as to filter out out-of-band noise in an effective signal of each channel; and in a third step, mismatching a pulse pressure and selecting large outputs so as to further improve the signal-to-interference ratio, i.e., designing a phase coded mismatched filter by utilizing a least square method, and selecting the large outputs for multiple pathsof data after mismatching the pulse pressure to obtain final output values.

The invention relates to the field of ventilation equipment, and is used for a plastic air supply device for an air conditioner. The plastic air supply device for the air conditioner includes an annular leaf baseplate, a wheel hub, a stream guiding ring and multiple blades. The outer diameter of the annular leaf baseplate ranges from 420 mm to 480 mm; the inner diameter size is 75%-85% of the outer diameter size of the annular leaf baseplate, and the shape from an air inlet end of each blade to an air outlet end of the blade is distorted; an upper air inlet angle is different from a lower air inlet angle and both angles are not greater than 10 degrees. An air outlet angle is different from an air outlet angle and both angles range from 20 degrees to 45 degrees. The upper portion of the blade is formed by a connection area and a disconnection area, wherein the connection area and the disconnection area are connected in an integrated mode. The air inlet area between any adjacent blades is 66%-75% of a corresponding air outlet area. The plastic air supply device for the air conditioner has the advantages of being novel in structure, huge in air volume and low in noise.

The invention provides a dual-layer three-dimensional noise reduction protection screen which comprises a plurality of flattop sound absorption wedges and a resonance noise elimination structure. The resonance noise elimination structure is composed of a three-dimensional support and a metal sheet. The three-dimensional support is of a box-type structure, the metal sheet is installed on one side of the three-dimensional support, the flattop sound absorption wedges are installed on the other side of the three-dimensional support, the metal sheet is provided with a plurality of micropores, a middle cavity of the three-dimensional support is filled with in-situ resonance materials, the flattop sound absorption wedges are of a pointless tetrahedral cone structure, and an inward-concave connecting groove is formed in the bottom of the protection screen. The dual-layer three-dimensional noise reduction protection screen is capable of effectively lowering low-frequency noise, easy to maintain, convenient to renew and longer in service life.

The invention discloses a single-channel speech enhancement method and device, a storage medium and a terminal. The method comprises the following steps: carrying out delay processing on a received input signal so as to obtain a delay signal; preprocessing noise in a current frame signal based on the delay signal to obtain an error signal, wherein the current frame signal is obtained from the input signal; carrying out noise estimation on the error signal and calculating an amplitude spectrum gain function; and calculating a frequency spectrum after speech enhancement according to the error signal and the amplitude spectrum gain function. According to the scheme of the invention, whistling noise can be effectively suppressed in a short time in a single-channel voice call scene, better voice quality can be maintained, and the voice quality of audio equipment such as single-channel voice call equipment, voice recording equipment and the like can be improved.

The invention discloses a purification exhaust pipe. The purification exhaust pipe comprises a shell, wherein the shell comprises an inlet cavity and an outlet cavity and is characterized in that twoshunting cavities communicate between the outlet cavity and the inlet cavity; transversely arranged communication pipes are arranged on the two side walls of the outlet cavity; evaporation air bags are symmetrically arranged on the inner side wall of each communication pipe and filled with evaporation liquid; a first magnet is slidably connected to the inner wall of each communication pipe; and apressure plate is slidably connected in the outlet cavity. According to the purification exhaust pipe, tail gas impacts on the pressure plate, and the kinetic energy of the tail gas is converted intothe kinetic energy of the pressure plate, so that the kinetic energy of the tail gas is reduced, the noise energy generated by the tail gas is synchronously weakened, and thus the noise is lowered; and the high-temperature tail gas is rapidly cooled under the action of cooling liquid, and the high-temperature damage of the tail gas to an exhaust system is greatly reduced due to the lowering of thetemperature, so that the service life of the exhaust pipe is effectively prolonged.

The invention discloses a low-noise pneumatic tire. The low-noise pneumatic tire is provided with a noise absorber mounted in a tire cavity, and the tire cavity is a closed space formed by the tire inner surface and a rim. The low-noise pneumatic tire is characterized in that the noise absorber is arranged in the tire cavity in the circumferential direction of the tire, and the noise absorber is provided with variational acoustic impedance in the circumferential direction of the tire; and the noise absorber takes the sound absorption material as a texture, and acoustic impedance is product ofspecific acoustic impedance of a sound absorption material and the superficial area of the sound absorption material. The low-noise pneumatic tire can effectively reduce total noise energy of cavity resonance, cavity resonance noise in the tire is better cut down, the sound absorption material utilization amount is reduced, the lightweight low-noise pneumatic tire can be manufactured, and the fuelconsumption and walk stability of an automobile are improved.

The invention discloses an impeller capable of increasing centrifugal pump noise tone quality and a design method thereof and belongs to the technical field of pumps. Normally, the blades of the impeller of a pump are distributed in an equal-distance manner and the exit edges of the blades are located on the same axial surface, so that intense dynamic and static interference exists between the blades and partition tongues, large noise energy is generated, the noise energy gathers under the signal blade passing frequency, the noise spectrum change shapely, and noise tone quality is poor. The impeller has the advantages that the distance between every two blades are optimized through a rotor automatic balance theory, a plurality of passing frequencies are generated, the noise energy gathered under the single blade passing frequency is reduced, corresponding noise pressure peak is reduced, the reduced noise energy is dispersed to other passing frequencies, stability of the noise spectrum is improved, the exit edges of the blades are allowed not to be located on the same axial plane, interference between the blades and partition tongues is weakened to a certain degree, the noise energy is reduced, overall noise amplitude is reduced, centrifugal pump noise tone quality is increased to a certain degree, and the impeller has certain popularization value.