55results about How to "Increased acoustic impedance" patented technology

A component operating with bulk acoustic waves has a carrier substrate, a thin-film resonator and an acoustic mirror arranged between the resonator and carrier substrate. The acoustic mirror is formed by at least one high acoustic impedance layer, which is covered by a low acoustic impedance layer and the uppermost low impedance acoustic layer is planarized to form a flat planar surface on which the thin-film resonator is formed.

A resonator device includes a piezoelectric resonator having a detuning layer sequence arranged on the piezoelectric resonator. The detuning layer sequence includes at least a first layer having a high acoustic impedance and a second layer having a low acoustic impedance.

An ultrasonically visible solid device for inserting into a non-gas target medium comprises an echogenic surface having structures entrapping gas when the device is in the target medium, the entrapped gas causing the device to be ultrasonically visible, wherein the gas-entrapping structures are covered with a flexible overcoat that does not significantly reduce the compressibility of the gas trapped in the structures.

The invention relates to a nanometer cellulose / polyvinyl alcohol gel composite material, which is characterized by comprising hydrogel and aerogel. A preparation method of the nanometer cellulose / polyvinyl alcohol gel composite material comprises the following process steps of 1, nanometer cellulose preparation by a chemical combination mechanical treatment method; 2, composite hydrogel preparation; and 3, composite aerogel preparation. The nanometer cellulose / polyvinyl alcohol gel composite material has the advantages that the composite aerogel belongs to a porous amorphous solid material consisting of nanometer level colloid particles or high-polymer molecules, and a unique open nanometer level porous structure and a continuous three-dimensional reticular structure are adopted, so the density is extremely low, the specific surface area is high, and the porosity is high, wherein the solid phase of the aerogel accounts for 0.2 percent to 20 percent of the total volume percentage, the characteristics of high adsorption catalytic capability, low thermal conductivity, low sound resistance, low refractive index and the like are shown, and wide application prospects are realized in the fields of aviation, spaceflight, chemical industry, metallurgy, energy-saving building and the like.

The invention discloses a high-frequency ultrasonic transducer made of a piezoelectric monocrystalline composite material as well as a manufacturing method and an application thereof. The high-frequency ultrasonic transducer consists of a piezoelectric monocrystalline composite material wafer, a damping backing material, a first matching layer, a second matching layer, a coaxial electrode lead, a coaxial connector and a metal shell, wherein the second matching layer, the first matching layer, the piezoelectric monocrystalline composite material wafer and the damping backing material are bonded together in sequence; and the coaxial electrode lead is introduced from the positive electrode and the negative electrode of the piezoelectric monocrystalline composite material wafer to the coaxial connector which is fixed on the metal shell. The invention provides a method for manufacturing the transducer by matching acoustic characteristic based on a KLM model. The center frequency Fc of the obtained ultrasonic transducer is equal to 14.67MH, the bandwidth Bw can be up to 107 percent and the pulse echo sensitivity Sr can reach -30dB; and the ultrasonic transducer also has very high sensitivity on the premises of high frequency and large bandwidth. The ultrasonic transducer can be used for medical diagnosis, ultrasonic nondestructive detection and precise thickness measurement.

A molded and shaped acoustical insulating vehicle panel having a dry-laid needled fibrous composite composed of a first portion of about 50 to 80 percent meltable binder fibers and about 20 to 50 percent stable fibers and having a second portion of about 20 to 50 percent meltable binder fibers and 50 to 80 percent of staple fibers. The meltable binder fibers are in a molded and resolidified state such that the resolidified binder fibers of the first portion form a substantially continuous, semi-impervious, densified skin integrally associated with and bonded to a surface of the first portion. The molded composite is in such a heat and pressure molded state that the composite has over a predominance of its area a density of from about 12 to 22 lbs. / cubic foot (192 to 352 kg / cubic meter) and the panel is sufficiently rigid as to be self-supporting.

A piezoelectric resonator with an acoustic Bragg reflector that includes alternating layers of high and low acoustic impedance materials. The high and low acoustic impedance dielectric materials make up electrically insulating layers.

An elastic wave device includes a supporting substrate including an upper surface including a recessed portion, a piezoelectric thin film on the supporting substrate to cover the recessed portion of the supporting substrate, an IDT electrode on a main surface of the piezoelectric thin film, the main surface being adjacent to the supporting substrate, and an intermediate layer on a main surface of the piezoelectric thin film, the main surface being remote from the supporting substrate. A space is defined by the supporting substrate and the piezoelectric thin film. The IDT electrode faces the space. Through holes are provided in the piezoelectric thin film and the intermediate layer to extend from a main surface of the intermediate layer to the space, the main surface being remote from the piezoelectric thin film. The elastic wave device further includes a cover member on the intermediate layer and covering opening ends of the through holes.

An ultrasound transducer includes an acoustic layer that includes a micromachined piezoelectric composite body having a front side and an opposite back side. The micromachined piezoelectric composite body is configured to convert electrical signals into ultrasound waves to be transmitted from the front side toward a target. The micromachined piezoelectric composite body is configured to convert received ultrasound waves into electrical signals. A dematching layer is connected to the back side of the micromachined piezoelectric composite body of the acoustic layer. The dematching layer has a higher acoustic impedance than an acoustic impedance of the acoustic layer.

Embodiments of thermal-acoustic sections for an aircraft for reducing noise along an acoustic path produced from an acoustic source are provided herein. The thermal-acoustic section comprises a first porous layer having a first characteristic acoustic impedance. A second porous layer is disposed adjacent to the first porous layer and has a second characteristic acoustic impedance that is greater than the first characteristic acoustic impedance. The thermal-acoustic section is configured to be positioned along the acoustic path such that at least a portion of the noise from the acoustic source is directed through the first porous layer to the second porous layer to promote absorption of the noise.

An ultrasonic flow meter is disclosed, the ultrasonic flow meter including a flow tube with a flow channel for a fluid to be measured, and two ultrasound reflectors fixated inside the flow tube, a first ultrasound transducer, a second ultrasound transducer, and an electronic control arrangement for operating the ultrasonic flow meter. The ultrasound transducers and reflectors have relative positions and orientations forming an ultrasound path from the first ultrasound transducer to the at least two ultrasound reflectors, to the second ultrasound transducer, and vice versa. The ultrasonic flow meter measures absolute transit times of the ultrasound signal from the first ultrasound transducer to the second ultrasound transducer, and / or vice versa, and the ultrasound reflectors include at least 50% by weight of copper, and the ultrasound signal includes at least 8 pulses.

A sensor device for monitoring a component of interest, including at least one sensor for measuring at least one parameter indicative of condition of the component of interest, signal processing device for processing the signals of the sensor, and a mounting element for mounting the sensor device close to the component of interest. The mounting element can be made of a zinc alloy.

An ultrasonic transducer for use in a fluid medium includes at least one housing having at least one inner space, at least one transducer core accommodated in the inner space, having at least one electroacoustic transducer element. The housing has at least one opening facing the fluid medium. The opening is covered at least partially by at least one sealing foil. An edge of the sealing foil is sealed by at least one sealing material.

Micro-electromechanical acoustic resonators include a substrate having a cavity therein and a resonator body suspended over the cavity. The resonator body is anchored on opposing sides thereof (by support beams) to first and second portions of the substrate. These first and second portions of the substrate, which extend over the cavity as first and second ledges, respectively, each have at least one perforation therein disposed over the cavity. These perforations may be open or filled. The first and second ledges are formed of a first material (e.g., silicon) and the first and second ledges are filled with a second material having a relatively high acoustic impedance relative to the first material. This second material may include a material selected from a group consisting of tungsten (W), copper (Cu), molybdenum (Mo).

A method for managing a fracturing operation. In one implementation, the method may include positioning a seismic source and at least one seismic receiver near a hydrocarbon reservoir; pumping a fracturing fluid into a well bore of the hydrocarbon reservoir such that the fracturing fluid may include an additive that enhances acoustic impedance between the fracturing fluid and subsurface formations in which the hydrocarbon reservoir is located and that produces a foam; performing a seismic survey with the seismic source and the at least one seismic receiver during the fracturing operation; and identifying locations of the fracturing fluid within subsurface formations in which the hydrocarbon reservoir is located.

A speaker box includes a frame defining an upper side and a lower side opposite to the upper side, an electroacoustic transducer received in the frame and including a diaphragm with an edge thereof being fixed to the upper side of the frame, a case defining a plate facing the diaphragm and a sidewall extending upwardly from the plate and positioned on the upper side of the frame, a room formed between the diaphragm and the case, a hole defined at the side of the case for outputting the sound wave produced by the diaphragm. The plate defines a plurality of slots extending from the joint of the plate and the sidewall to towards the hole to connect to the hole, the slots being spaced each other and configured for leading the air of the room to get out through the hole.

An elastic wave device in which an IDT electrode defines an excitation electrode on a piezoelectric layer, an acoustic reflection layer is laminated on a first main surface of the piezoelectric layer, the acoustic reflection layer includes high acoustic impedance layers with a relatively high acoustic impedance and low acoustic impedance layers with a relatively low acoustic impedance, and the acoustic reflection layer has an unwanted wave reflection suppression structure in which reflection of unwanted waves toward the piezoelectric layer side is significantly reduced or prevented.

A ventilation and noise reduction system for centralized cooling towers includes a wind outlet sound-reduction structure, a wind inlet sound-reduction channel, a rainwater collection system, and an arrestor device; wherein the integrated sound-absorbing and sound-insulation shed includes a loading-bearing installation structure for a lifting ring, a concrete foundation, a bearing support structure, a ceiling installation structure, a sound-insulation structure and a lighting and sound-insulation structure.

An ultrasonic transducer for use in a fluid medium includes at least one housing having at least one inner space, at least one transducer core accommodated in the inner space, having at least one electroacoustic transducer element. The housing has at least one opening facing the fluid medium. The opening is covered at least partially by at least one sealing foil. An edge of the sealing foil is sealed by at least one sealing material.

The invention discloses a reactive muffler structure with combination of perforated pipes and narrow-slit resonant cavities. The reactive muffler structure with the combination of the perforated pipes and the narrow-slit resonant cavities comprises a cylinder body, an air inlet perforated pipe and a transverse flow perforated pipe, wherein the cylinder body is divided into a left chamber and a right chamber by a longitudinal separating plate II, the left chamber is divided into an upper chamber and a lower chamber by a transverse separating plate, the upper chamber and the lower chamber are communicated, the lower chamber is divided by a longitudinal separating plate I, the air inlet perforated pipe penetrates through the lower chamber and the longitudinal separating plate I, the transverse flow perforated pipe penetrates through the upper chamber to reach the interior of the right chamber, and the top of the right chamber is communicated with an air outlet pipe. The reactive muffler structure with the combination of the perforated pipes and the narrow-slit resonant cavities is simple and reasonable in structure, comprehensively utilizes the silencing characteristic of the perforated pipes and structures of the narrow-slit resonant cavities, is low in pressure loss, high in silencing capacity, and obviously good in silencing effect of a low-frequency stage which corresponds to the ignition frequency of a common engineering machinery engine.

The invention discloses a refrigerator and an air duct plate of the refrigerator. The refrigerator comprises a refrigerator body which is internally provided with refrigerating chambers, door bodies installed on the refrigerator body and used for opening or closing the refrigerating chambers and an air duct arranged in the refrigerator body, wherein the air duct comprises the air duct plate, and silencing blind holes spaced to one another are formed in the inner wall face of the air duct plate. According to the refrigerator, due to the fact that the silencing blind holes are formed in the inner wall face of the air duct plate, noise can form resonance at peak frequency bands, so that the silencing coefficient and the sound resistance of the air duct plate are improved, and the sound absorption bandwidth is enlarged. In addition, the silencing blind holes formed in the inner wall face of the air duct plate are used for replacing silencing cotton to reduce fluid noise generated when air flow flows through the air duct plate, secondary noise brought by the silencing cotton is lowered, the problem that the air duct is blocked by ice due to water absorption of sound absorption cotton is effectively solved, the production cost is reduced, and the long-term operation reliability of the product is improved.

The invention provides an all-weather and all-area intelligent bird repelling system and device. The all-weather and all-area intelligent bird repelling system is mainly composed of a detection and sensing module, an information comprehensive processing module, a multi-energy repelling module and a man-machine interaction module; the detection and sensing module is mainly composed of a bird detection radar, a photoelectric system, a servo control system and a multifunctional rotary table; the information comprehensive processing module adopts a high-speed processing controller hardware architecture to complete information acquisition and processing, data fusion, artificial intelligence model calculation and intelligent control and deep learning; the multi-energy repelling module adopts strong sound bird repelling and blue light bird repelling means, and continuously executes various different repelling combination modes; and the man-machine interaction module is capable of intelligently monitoring bird target information and sending an instruction according to the information. The system and the device have the comprehensive prevention functions of intelligently detecting, sensing and acquiring data, fusing the data, then performing artificial intelligence edge calculation, performing various sound and light repelling modes, and finally performing continuous iterative optimization according to driving effect evaluation and machine deep learning.

A probe for an ultrasonic diagnostic apparatus includes a case, a piezoelectric member provided inside the case, at least one acoustic matching layer disposed at a front of the piezoelectric member, an acoustic lens disposed at a front of the acoustic matching layer, and a backing member disposed at a rear of the piezoelectric member and provided with a plurality of pores to reduce sound waves transmitted to the rear of the piezoelectric member and to allow to adjust an acoustic impedance. A method of manufacturing the probe for an ultrasonic diagnostic apparatus includes the operations of preparing a fluid to form a backing layer, pouring the fluid into a mold, hardening the fluid and removing the mold.

A method for managing a fracturing operation. In one implementation, the method may include positioning a seismic source and at least one seismic receiver near a hydrocarbon reservoir; pumping a fracturing fluid into a well bore of the hydrocarbon reservoir such that the fracturing fluid may include an additive that enhances acoustic impedance between the fracturing fluid and subsurface formations in which the hydrocarbon reservoir is located and that produces a foam; performing a seismic survey with the seismic source and the at least one seismic receiver during the fracturing operation; and identifying locations of the fracturing fluid within subsurface formations in which the hydrocarbon reservoir is located.

The acoustic rubber-fiber ball board includes main boards, flat, corrugated or curved; and steel fiber balls comprising irregularly steel filaments or strips inside the main boards. It has different sound absorbing engineering structures to absorb and consume sound waves to reach silencing effect. It may be used in highway, railway, hall and other engineering to absorb sound and reduce noise and has low manufacture cost. Its surface may have increased reflecting strips to reflect sound to the air and raise the silencing effect.