131 results about "Acoustic attenuation" patented technology

The application relates to a method for measuring coating interface stiffness by using ultrasonic echo phase first derivative spectrum, belonging to the technical field of ultrasonic nondestructive testing. The method detects a coating sample by vertical incidence of ultrasonic waves, collects aliasing echoes of a coupling medium / coating and a coating / substrate interface P R , carries out fast Fourier transform to obtain an unwound phase P R , carries out fast Fourier transform to obtain an unwound phase R , carries out fast Fourier transform to obtain an unwound phase R , carries out fast Fourier transform to obtain an unwound phase f , carries out fast Fourier transform to obtain an unwound phase K , carries out fast Fourier transform to obtain an unwound phase n , carries out fast Fourier transform to obtain an unwound phase The method reduces the influence of material sound attenuation, interface roughness and other factors on the detection result, has high quantitative precision, wide application range, large detection depth range, easy operation and other advantages, and is free from the dependence on a high-quality reference signal in traditional construction of URCAS or URCPS.

The invention relates to a fruit maturity nondestructive intelligent detection method and system based on high-frequency dynamic excitation and acoustic vibration signal analysis. The method comprises the following steps: controlling an excitation device to apply high-frequency transient mechanical excitation to a fruit; synchronously collecting a vibration response signal on the surface of the fruit and an internal sound wave signal; extracting dynamic feature vectors including formant characteristics, sound wave attenuation coefficients and time domain attenuation constants from the sound vibration signals; inputting the feature vector into a time sequence convolutional network model to obtain a final maturity grade and a judgment confidence coefficient; and starting an active learning mechanism for a low-confidence sample, and continuously optimizing the model through manual annotation and incremental learning. By detecting the internal physical characteristics of the fruits, the defects that the traditional visual and tactile methods are interfered by surface states and the internal maturity is difficult to judge are overcome, and rapid, lossless and high-precision intelligent detection of the maturity of the fruits with self-evolution capability is realized.

The utility model belongs to the technical field of reactors, and particularly relates to an extra-high voltage shunt reactor oil tank composite noise reduction structure which comprises a rubber plate fixedly installed in an oil tank wall, the outer side of the rubber plate is attached to the surface of the inner side wall of the oil tank wall, and a sound absorption hole-free paperboard is fixedly installed on the inner side of the rubber plate. A double-layer composite perforated plate sound absorption mechanism is fixedly installed on the inner side of the sound absorption hole-free paperboard, gaps are reserved among the rubber plate, the sound absorption hole-free paperboard and the double-layer composite perforated plate sound absorption mechanism, and a gap is reserved between two layers of perforated plates of the double-layer composite perforated plate sound absorption mechanism. The double-layer composite perforated plate sound absorption mechanism comprises a first perforated paperboard and a second perforated paperboard. The composite noise attenuation structure composed of the rubber plate and the multiple layers of insulating paper plates is arranged on the inner side wall of the oil tank, vibration waves transmitted from insulating oil are blocked and weakened through material combination of different media, vibration noise can be reduced, and the composite noise attenuation oil tank is an important measure for solving the problem of noise of an electric reactor.

The invention provides indoor air quality monitoring equipment and a sensor cooperative control system, relates to the technical field of indoor environment monitoring, and is used for solving the problems of response delay, temperature drift accumulation and alarm accessibility reduction in long-term operation of an air monitoring device. The device realizes feed-forward identification and closed-loop suppression of sample injection degradation, filter material pollution and dislocation, heat drift in the machine and acoustic attenuation: a sampling confirmation window is adaptively adjusted to reduce misjudgment, channel-level temperature drift compensation and power consumption derating are cooperatively executed according to priorities to realize steady-state temperature control, and a prompt link keeps subjective loudness consistent based on equivalent gain; meanwhile, the baseline is refreshed after maintenance to maintain long-term consistency; therefore, under the condition that the mechanical appearance is not changed, the monitoring accuracy, stability and alarm accessibility are remarkably improved, and the device-level design value of structural perception driving is highlighted.

The invention discloses an intelligent design system and method for an aviation airborne porous system complex flow channel shell part, and relates to the technical field of intelligent design, and the system comprises a data obtaining module which is used for obtaining a three-dimensional flow channel shell model, a working condition parameter set and a manufacturing limit; the feature extraction and arrangement band generation module is used for generating a candidate arrangement band; the hole group design and optimization module is used for generating a circumferential shallow cavity communication scheme and hole group arrangement; the acoustic impedance synthesis module is used for constructing equivalent surface complex impedance; the performance index calculation and association module is used for constructing system insertion loss and system additional voltage drop indexes; the multi-target tradeoff and solution verification module is used for obtaining a definite solution; and the design and manufacturing output module is used for taking the determined solution as parameterized computer aided design data and formulating manufacturing key points. According to the method, the arrangement area can be accurately selected in the complex flow channel, the controlled hole group can be constructed, and both noise attenuation and flow loss are considered.

This disclosure provides a wedge and design method for a multipath acoustic attenuation phased array ultrasonic testing probe. The wedge includes a wedge body, multiple silencing grooves, and a damping block. The extension direction, spacing, and depth of each silencing groove are configured such that at least a portion of the reflected transverse wave generated at the detection surface can be guided to an attenuation interface formed by the groove wall of the silencing groove and the damping block. Furthermore, the reflected longitudinal wave generated at the detection surface undergoes at least six interface reflections within the wedge body before returning to the probe direction. The acoustic characteristics of the damping block are configured to absorb the reflected transverse wave. The reflected transverse wave is attenuated at the attenuation interface through a combination of scattering by the silencing groove and absorption by the damping block. After at least six interface reflections, the acoustic component of the reflected longitudinal wave returning to the probe direction forms a 180° phase difference with the incident longitudinal wave emitted by the probe, thus being attenuated through phase interference.

The invention relates to a method for influence of dislocation dipole defects in an aluminum matrix on acoustic parameters, belongs to the technical field of discrete solution, and provides a novel molecular dynamics simulation method for researching ultrasonic sound velocity, sound attenuation and acoustic nonlinear parameter change on the basis of two dislocation dipole structures. The method specifically comprises the following steps: controlling the type and the number of dislocation dipoles in an aluminum matrix, carrying out atomic scale acoustic simulation on dislocation dipole models of different types and numbers by adopting a phase inversion technology, extracting sound velocity by adopting a cross correlation method, extracting sound attenuation by adopting a Hilbert transformation method and extracting acoustic nonlinear parameters by adopting an FFT method aiming at four-phase signals; and precise extraction of acoustic parameters is realized. And determining the contribution of the dislocation defect to the acoustic parameters based on the relationship fitting of the three acoustic parameters and the dislocation defect, thereby realizing the prediction from the acoustic parameters to defect characteristics.

The invention discloses an ultrasonic sound attenuation display method and ultrasonic equipment, and the method comprises the steps: displaying an interface used for selecting a sound attenuation scanning mode, scanning a target tissue based on a first sound attenuation scanning mode in response to a first selection instruction, and obtaining a multi-frame sound attenuation result of a first target region of the target tissue; displaying a multi-frame sound attenuation statistical index of the first target area according to the multi-frame sound attenuation result of the first target area; under the condition that the multi-frame sound attenuation statistical index of the first target area does not meet a first index condition, first abnormity prompting is carried out; in response to the second selection instruction, scanning the target tissue based on a second sound attenuation scanning mode to obtain a single-frame sound attenuation result of a second target area of the target tissue; displaying a single-frame sound attenuation statistical index of the second target area according to the single-frame sound attenuation result of the second target area; and under the condition that the single-frame sound attenuation statistical index of the second target area does not meet a second index condition, carrying out second abnormity prompting.

The invention provides an ultrasonic plane wave multi-mode cooperative imaging method and system, and the method comprises the steps: controlling an ultrasonic probe to execute shear wave elastic imaging and sound attenuation imaging of which the mechanical index is equal to or greater than a first threshold value based on a multi-level voltage control scheme; and executing super-resolution imaging with the mechanical index smaller than or equal to a second threshold value after the super-resolution imaging is completed. The method comprises the following steps: acquiring a sound attenuation coefficient graph generated in a sound attenuation imaging process, and respectively acquiring a first super-resolution graph without contrast agent perfusion, a second super-resolution graph with contrast agent perfusion and a tissue elasticity graph generated in a shear wave elasticity imaging process based on an ultrafast plane wave technology; performing post-processing on the collected first super-resolution graph to generate a probability density graph of the tissue structure, and performing post-processing on the collected second super-resolution graph to generate a microbubble tracking speed graph; and carrying out cooperative imaging on the tissue elasticity map, the sound attenuation coefficient map, the probability density map and the velocity map. The imaging comprehensiveness and accuracy are improved, and early lesion diagnosis is facilitated.

The invention relates to a method for manufacturing a honeycomb core for an acoustic attenuation panel, the honeycomb core comprising a plurality of cells, and obstacles within the cells, comprising: a step of forming a stack (50) comprising a plurality of strips (51, 52), at least one interlayer film (53) being intercalated between two adjacent strips, the interlayer film (53) being attached to each of the adjacent strips (51, 52) along the junction zones, and attached to itself within the portions (533a) of folds (533) located along the junction zones, the interlayer film (53) comprising, at the level of each zone of the stack (50) intended to form an end of a cell, a sacrificial fold; a step of applying pressure, during which pressure is exerted on the stack (50) in a vertical direction (VE);a forming step, during which the stack (50) is stretched along the vertical direction (VE); a step of removing sacrificial folds. Figure 4.;

The application aims to provide a contrast test block preparation method and contrast test block for ultrasonic detection, which comprises the following steps: obtaining the configuration of a woven preform, dividing the configuration of the woven preform into at least two detection partitions, determining the number, size and position distribution of artificial defects in each detection partition, preparing the artificial defects by using a large sound attenuation material, implanting the artificial defects into the corresponding detection partition of the woven preform, and detecting the woven preform with the pre-prepared artificial defects after glue injection and solidification molding. The test block prepared by the method can realize the detection of three-dimensional woven composite members.

An ultrasonic diagnostic imaging system and method produce attenuation coefficient maps of a region of interest in an ultrasound image. In order to detect the presence of elevation aperture blockage, the system estimates attenuation coefficients by two different methods. The estimates produced by the two different methods are combined to produce a metric, which is evaluated as a function of depth. If the metric satisfies one or more criteria of measurement bias, elevation aperture blockage is identified and an alert of the blockage is produced for the user.

Propulsion assembly for an aircraft, comprising a turbomachine (1), an attachment strut (40) and a structural element (10) carrying the turbomachine (1) by the attachment strut (40), the turbomachine having at least one rotating part (30) rotating about an axis of rotation (A), the rotating part (30) being arranged upstream of the structural element (10) and of the attachment strut (40) so that the air jet exiting from the rotating part (30) impacts the structural element (10) and the attachment strut (40) in the wake thereof, the leading edge of the structural element (10) and / or of the attachment strut (40) locally comprising at least one acoustic attenuation device (50, 60, 70, 80) arranged at least partially in the wake of the rotating part (30), the acoustic attenuation device being a partial modification of the structure and / or of the profile of the leading edge (11).

Acoustic attenuation assembly for a motor vehicle brake pedal assembly and a vehicle comprising such an assembly. The invention relates to an acoustic attenuation assembly for a vehicle brake pedal assembly (7), comprising: - an apron (9) behind which a passenger compartment is arranged and in front of which an engine compartment is arranged, - a brake pedal assembly (7), comprising a bracket (21) adapted to support a brake pedal actuated from said passenger compartment, fixed to said apron (9) and extending into said passenger compartment, - a brake amplifier (15), comprising an actuating rod (19) for a hydraulic control of a braking system passing through a cutout (23) made in said apron (9) and extending into a cavity (25) of said bracket.According to the invention, the assembly includes an acoustic attenuation device (27) radially connecting said clevis (21) and said actuating rod (19), comprising an acoustic attenuation material suitable for attenuating sound waves passing through it. Figure 3.

The invention relates to the technical field of medical image processing, in particular to a kidney ultrasonic image-based fibrosis quantitative evaluation method and system, and the method comprises the steps: obtaining an ultrasonic image, carrying out the standardization processing, and estimating a system response correction function and an optical flow field; selecting a key frame based on an optical flow field, performing registration and constructing pose map optimization, fusing a envelope to establish mapping between a cortical conformal coordinate system and a key frame pixel, and generating a cortical region probability field and a boundary uncertainty field; calculating a sound attenuation coefficient and a scattering statistical parameter in the sliding analysis window, correcting the sound attenuation coefficient and the scattering statistical parameter, projecting the sound attenuation coefficient and the scattering statistical parameter to a conformal coordinate system, carrying out Wasserstein gravity center fusion according to probability and uncertainty weighting, detecting the effective thickness of the cortex, and carrying out consensus optimization to obtain a fibrosis fraction field and a consensus residual field; and generating a non-consistency total score, outputting a confidence interval and a confidence level through conformal prediction calibration, and generating a fallback recalculation or re-collection instruction if necessary. The cross-view, cross-time and cross-equipment consistency is improved, and the closed-loop quality control capability is achieved.

The application is a method for the influence of dislocation dipole defects in aluminum matrix on acoustic parameters, belonging to the technical field of discrete solution, and provides a new molecular dynamics simulation method for researching the changes of ultrasonic velocity, acoustic attenuation and acoustic nonlinear parameters based on two dislocation dipole structures, specifically, the types and quantities of dislocation dipoles in the aluminum matrix are controlled, the atomic scale acoustic simulation is carried out on the dislocation dipole models of different types and quantities by using the phase inversion technology, the cross correlation method is used to extract the sound velocity, the Hilbert transform method is used to extract the sound attenuation, and the FFT method is used to extract the acoustic nonlinear parameters for the four-phase signals, so as to realize the precise extraction of acoustic parameters. Based on the fitting relationship between the three acoustic parameters and the dislocation defects, the contribution of the dislocation defects to the acoustic parameters is determined, and the prediction from the acoustic parameters to the defect characteristics is realized.

The application provides an ultrasonic attenuation compensation method and device and electronic equipment, for each point of interest in an ultrasonic image, a sound channel is determined according to a plurality of ultrasonic transmitting elements arranged on an ultrasonic probe; for each sound channel, target data of each pixel point on the sound channel is obtained from the ultrasonic image; and according to the target data, an ultrasonic attenuation value for the point of interest is calculated to compensate ultrasonic energy emitted to the point of interest. According to the method, the sound channel is determined according to each point of interest in the ultrasonic image in combination with the ultrasonic transmitting elements, and then the ultrasonic attenuation value for the point of interest is determined according to the target data such as the gray value and TGC value of each pixel point on the sound channel. Since the target data of different pixel points can reflect the heterogeneity of the acoustic impedance of different individuals, the accuracy of the obtained ultrasonic attenuation value can be improved, and the accuracy of the compensation of the ultrasonic energy is improved.

The invention provides a method and a device for detecting cracks of a graphite crucible, and relates to the technical field of nondestructive testing. The method comprises the following steps: transmitting ultrasonic waves to a graphite crucible in a non-contact manner and receiving returned ultrasonic signals by adopting a gas coupling ultrasonic transmitting and receiving assembly; processing the signal using a trained deep learning model to identify cracks within the crucible and determine geometric parameters thereof; and finally, generating and outputting a detection report. Pollution to the porous graphite material is avoided in a gas coupling mode, meanwhile, the technical problems that signals are weak due to high sound attenuation of the material and detection is difficult to achieve through a traditional method are solved by means of the feature learning capacity of the deep learning model, and the micro cracks can be recognized from background noise. Pollution-free and automatic detection of the graphite crucible is realized, and the detection precision and efficiency are improved.

This invention provides an indoor air quality monitoring device and sensor collaborative control system, relating to the field of indoor environmental monitoring technology. It addresses the problems of response lag, temperature drift accumulation, and decreased alarm reachability that occur during long-term operation of air monitoring devices. By treating structural influences as a first-type input and unifying their parameterization, the device achieves feedforward identification and closed-loop suppression of sample degradation, filter material contamination and misalignment, internal thermal drift, and acoustic attenuation. The sampling confirmation window is adaptively adjusted to reduce false alarms; channel-level temperature drift compensation and power derating are prioritized and executed collaboratively for steady-state temperature control; the alert link maintains subjective loudness consistency based on equivalent gain; and the baseline is refreshed after maintenance to maintain long-term consistency. Thus, without altering the mechanical form, the device significantly improves monitoring accuracy, stability, and alarm reachability, highlighting the value of structure-aware driven device-level design.

The invention relates to an acoustic attenuation panel (40) comprising: - a perforated acoustic wall (42), - a first honeycomb structure (44) connected to the perforated acoustic wall (42) having a plurality of acoustic cells (440) delimited by perimeter partitions (445), - a second honeycomb structure (48) having a plurality of acoustic cells (480) delimited by perimeter partitions (485), - a septum (46) having a plurality of large perforations (460), the septum being interposed between the first honeycomb structure (44) and the second honeycomb structure (48), each acoustic cell (440) of the first honeycomb structure and each acoustic cell (480) of the at least one second honeycomb structure (48) being arranged opposite a distinct perforation (460) of the septum (46).

The invention discloses a multi-unmanned aerial vehicle sound source positioning search and rescue system and method for mountain forest search and rescue tasks. The method comprises the following steps: constructing a near-crown safe flight surface based on terrain and a crown, and rasterizing a reachable area; the sequential SMT is landed to a multi-unmanned-aerial-vehicle mountain forest search and rescue task, the trajectory planning solving rate is accelerated, and the availability of a group search task is enhanced; the unmanned aerial vehicle flies along a set track, the annular multi-microphone array and the IMU collect data, and a sound source probability heat map is generated in combination with an acoustic attenuation model; and after the task is finished, carrying out peak value clustering on the heat map, outputting candidate coordinates and a priority list, and providing guidance for ground search and rescue personnel. The system is composed of suspension vibration reduction, array sensing, embedded processing, wireless communication and an independent power supply, and is modularized and quickly assembled. The actual measurement shows that the average positioning error is 5.44 m in 21.05 hectare forest land, the coverage efficiency is improved by about three times, and the method is suitable for unmanned aerial vehicle emergency search and rescue.

This invention relates to the field of marine engineering and structural health monitoring technology, specifically a three-dimensional identification method for overburden fissures in submarine tunnels. When there are no fissures in the propagation path between the acoustic signal transmitter and receiver, the received signal is stable; however, when fissures exist in the path, the received signal will show significant attenuation or a sharp drop. This invention achieves online, rapid, and accurate detection of overburden fissures in submarine tunnels through a multi-source spatial superposition identification algorithm based on acoustic attenuation characteristics. Utilizing the principle of multi-path superposition, it can eliminate single-path measurement errors and improve positioning accuracy. The system has a high degree of automation, can quickly acquire and process signals, and meets the online monitoring needs during construction. The equipment is flexible in installation; the transmitter only needs to be placed outside the overburden layer, reducing modifications to the internal structure of the tunnel.

An EMI shielding and acoustic attenuation door frame and door system, including: a door connected to a door frame with a hinge, the door including a bottom portion having a plate, a door gasket, a door sponge, and conductive tape for grounding the door; the door frame including: a jamb section including: a jamb main frame; a jamb back frame; wherein the jamb main frame and back frame being adjustable along the wall; a layered jamb gasket at least partially in between the door frame and the jamb main frame; a flanged magnetic jamb gasket fixed to an acoustical retainer with a fastener; wherein the door is grounded when the door is in a closed position against the door frame; a sill section including: a spreader bar having at least one sill gasket covered by a threshold, the spreader bar and at least one sill gasket contacting a floor shielding.

The invention provides a DAS water content identification method based on shaft axial acoustic attenuation characteristics. The method comprises the following steps: acquiring DAS acoustic time-domain signals of a plurality of axial positions of a shaft by using a distributed optical fiber; performing preprocessing and frequency domain transformation on the time domain signal to obtain an acoustic frequency spectrum distributed along the axial direction of the shaft; according to the law that the acoustic spectrum amplitude changes along with the position, calculating an acoustic space attenuation feature alpha (f) by adopting least square fitting based on the distance; constructing an attenuation spectrum based on the spatial attenuation characteristics, and extracting attenuation characteristic parameters related to the moisture content from the attenuation spectrum; constructing a training set and establishing a support vector machine (SVM) moisture content identification model based on a radial basis function (RBF); and inputting the actual attenuation characteristic parameters into the trained SVM model to obtain the predicted moisture content. The invention further discloses a water content identification system for executing the method and a storage medium, and the system and the storage medium are suitable for identifying the water content of the oil well shaft fluid.

The present invention relates to an installation (2) for distributing an air flow, the installation (2) comprising at least one circulation duct (4) comprising an acoustic attenuation sector (6) that has at least a first straight portion (8), a second straight portion (10) and a third, intermediate portion (12), wherein the first straight portion (8) comprises a first wall (14) inscribed in a first plane (P1) and a second wall (16) inscribed in a second plane (P2), the first wall (14) being opposite the second wall (16), the second straight portion (10) comprising at least one of its walls inscribed in an extension plane (P3) extending in a space defined between the first plane (P1) and the second plane (P2).

An ultrasound probe includes an ultrasound transducer stack comprising one or more ultrasound transducers emitting an acoustic signal, and an acoustic window passing the acoustic signal. The acoustic window is composed of a butadiene-based compound. In one or more embodiments, the acoustic window is made of butadiene rubber. Butadiene rubber has acoustic characteristics that may be suitable for acoustic windows, as subsequently discussed. Specifically, the use of butadiene rubber may result in desirable acoustic attenuation, acoustic velocity and acoustic impedance.

The application discloses a seabed sediment layer acoustic characteristic analysis method based on wavelet consistency joint calibration and belongs to the technical field of marine engineering investigation and seabed detection. The method comprises the following steps: denoising the collected sound wave data in water and the seabed sediment layer to obtain an actual water sound field and an actual sediment layer sound field; establishing a reference sound field based on a zero-phase bandwidth wavelet by using the water acoustic characteristics; solving a matched filter of the actual water sound field and the reference sound field; applying the matched filter to the actual sediment layer sound field, picking up the peak time and amplitude of each channel of the filtered sediment layer sound field by using envelope fitting; and inverting the acoustic characteristic parameters of the sediment layer based on the obtained peak time and amplitude, wherein the acoustic characteristic parameters include the sound velocity and the sound attenuation factor. The application can obtain accurate calculation results of the sediment layer acoustic characteristics.

The application provides a working method of a combined measurement device for the acoustic and electric characteristics of a polymetallic nodule, and aims at the limitation of a single physical field measurement technology in the traditional deep-sea polymetallic nodule research, and the problems that the existing method is greatly disturbed by the environment and cannot synchronously acquire acoustic and electric characteristics. The application provides an integrated measurement device. The device synchronously measures the sound velocity, acoustic impedance and acoustic attenuation coefficient of the polymetallic nodule through an ultrasonic transmission method, and measures the surface voltage and resistivity of the polymetallic nodule by combining a two-pole method and an equivalent conversion model. The synchronous acquisition and analysis of the acoustic and electric characteristics are realized, high-precision data support is provided for the deep-sea mineral resource exploration, mineral composition analysis and mining process optimization, and the application can be extended to the comprehensive characteristic research of various metal minerals.

A method employing the principle of mechanical reciprocity to image the relative acoustic attenuation called shear wave reciprocity imaging (SRI). SRI does not require the pre-stored sample signal for acoustic attenuation evaluation. In SRI, sequential marching pushes similar to acoustic radiation force impulse (ARFI) imaging are excited from an array transducer, and the reciprocal displacements are collected similarly to the plane wave single-track location method (p-STL).

This utility model relates to the field of ventilation and noise reduction technology, and discloses a silencing box, including a box body assembled from several silencing panels; an air inlet is provided on one side of the box body, and an air outlet is provided on the opposite side; wherein the air inlet and air outlet are at different heights; a partition component assembled from the silencing panels is disposed within the box body to divide the box body into a first silencing chamber and a second silencing chamber; the first silencing chamber is connected to the air inlet and air outlet; the second silencing chamber is also connected to the air inlet and air outlet; a flow guiding structure is disposed within at least one of the first and second silencing chambers; wherein the flow guiding structure is used to form a "Z"-shaped air duct within its respective silencing chamber to guide airflow. This utility model significantly improves broadband noise attenuation efficiency through the synergistic effect of the dual-chamber layout and the zigzag air duct, while the modular assembly structure facilitates maintenance and expansion, combining the advantages of high noise reduction performance and low maintenance costs.