84 results about "Piezodorus" patented technology

The present invention relates to the technical field of measuring electrical variables, and in particular to a multi-dimensional force measurement device that takes into account both static and dynamic measurements. This device solves the technical problems of traditional six-dimensional force sensors, such as complex and cumbersome structures, overall weight, inability to take into account both static and dynamic measurements, and low measurement accuracy. The device comprises a measurement component and a vibration isolation component; the measurement component comprises a base plate, a top plate, and a cantilever beam; the cantilever beam is connected to the base plate, and the cantilever beam is inserted into a limit groove of the top plate through a support arm. The cantilever beam is provided with a uniaxial strain gauge, a first biaxial strain gauge, a second biaxial strain gauge, an X-type piezoelectric crystal, a first Y-type piezoelectric crystal, and a second Y-type piezoelectric crystal; the vibration isolation component comprises a first horizontal support plate, a second horizontal support plate, a multi-layer isolation sleeve, and a support column, and the adjacent isolation sleeve interlayers are filled with elastic material. The device realizes the combination of static and dynamic measurements, and can capture rapidly changing torques and forces while maintaining high accuracy.

Systems and methods for measuring wall thicknesses include an ultrasonic transducer including a cylindrical housing defining a sensing plane at an end of the cylindrical housing; and a plurality of piezoelectric crystals disposed in the cylindrical housing in a circular configuration with a face of each piezoelectric crystal coincident with the sensing plane, each piezoelectric crystal being operable to transmit and receive ultrasonic waves.

The invention discloses a sensing unit structure of a piezoelectric-piezoresistive coupling type electric field sensor and application, the sensing unit structure comprises a substrate, the substrate is provided with a cantilever beam structure, a piezoelectric crystal block is bonded between the lower surface of the cantilever beam structure and the upper surface of the substrate, and the upper surface of the cantilever beam structure is provided with a Wheatstone full-bridge structure; when the piezoelectric crystal block is subjected to the action of an electric field, the piezoelectric crystal block deforms in the Z-axis direction under the action of an inverse piezoelectric effect, so that the cantilever beam structure deforms; in the Wheatstone full-bridge structure, the resistors arranged at the position with the maximum stress difference value are stressed to deform, the stress directions of the resistors are opposite, and the resistance values of the resistors are changed oppositely; compared with the sensing unit structures of electro-optical and mechanical electric field sensors commonly used at present, the sensing unit structure has the advantages of larger measuring range, smaller volume, lower power consumption and easiness in mass production.

The invention discloses an electric transport measuring device and method, and the device comprises a probe structure which comprises a sample stage, a quantum probe assembly and an optical assembly, the sample stage is used for placing a to-be-measured sample, and an electric transport measuring condition is applied to the to-be-measured sample, so as to obtain an electric transport measuring signal; the quantum probe assembly is provided with a tuning fork and a piezoelectric crystal. The free end of the tuning fork is provided with an NV probe. The optical assembly emits exciting light, the exciting light is focused to the NV probe, microwave radiation is applied to the NV probe, and a fluorescence signal emitted by the NV probe is collected; the device also includes a control module for performing performance analysis based on the fluorescence signal and the electrical transport measurement signal. The electric transport measurement condition is applied to the to-be-measured sample through the sample table so as to obtain the electric transport measurement signal, and the electric transport characteristic is represented by monitoring the magnetic signal in combination with the quantum scanning magnetic imaging technology, so that the injection and extraction difficulty of local microscopic charges is reduced, and the measurement efficiency is improved.

The invention discloses a stop valve based on sealing performance self-inspection, and relates to the technical field of stop valves. Comprising a valve body, a valve cover, a valve clack assembly, a valve rod, a hand wheel, a protection assembly and a support, displacement generated when a lower valve clack is closed is utilized, a sealing detection groove is automatically opened, leakage liquid is guided and collected, a detection ring is driven by the leakage liquid to move upwards, accordingly, a detection block is driven to extrude a transmission block, a piezoelectric crystal is finally triggered, leakage physical quantity is converted into quantifiable electric signals, and the leakage physical quantity is detected. And the purpose of sealing self-inspection is achieved. When the valve clack assembly is opened, the design that the lower valve clack rebounds automatically is utilized, the liquid drainage ring is driven to be embedded into the sealing measuring groove, leakage liquid in the sealing measuring groove is squeezed out, and the liquid drainage effect is achieved. The lower valve clack and the upper valve clack are made to be close to each other through downward pressure generated when the valve clack assembly is closed, the air bag ring is extruded, the air bag ring generates one-way expansion to conduct secondary sealing on the closure opening, and the multiple sealing effect on the closure opening is achieved in combination with primary sealing between the upper valve clack and the closure opening and between the lower valve clack and the closure opening.

The invention discloses a surface acoustic wave hydrogen sensor based on a platinum and graphene composite film and a manufacturing method thereof, and belongs to the technical field of gas sensors, the surface acoustic wave hydrogen sensor comprises a piezo-electric crystal, the piezo-electric crystal is oppositely provided with a first interdigital transducer and a second interdigital transducer, a graphene film is deposited on the piezoelectric crystal and located on a sound propagation path between the first interdigital transducer and the second interdigital transducer, a platinum catalyst layer film is deposited on the surface of the graphene film, and the first interdigital transducer and the second interdigital transducer are connected with an external circuit through metal pins. The external circuit comprises a signal generator, a frequency meter and a data acquisition system, the signal generator generates an excitation signal and transmits the excitation signal to the first interdigital transducer through the metal pin, and a detection signal generated by the interdigital transducers is received by the data acquisition system and then is detected and compared through the frequency meter. The problems that an existing pure graphene hydrogen sensor is low in sensitivity, poor in selectivity and slow in response time can be solved.

This invention provides a glass-based heterogeneous integrated structure with back vias and its fabrication method. Back vias are designed on a heterogeneous integrated wafer. The heterogeneous integrated wafer includes a glass substrate and a piezoelectric crystal layer, or at least one heterogeneous thin film layer is bonded between the glass substrate and the piezoelectric crystal layer. The back vias are blind vias and / or through-holes, with the blind vias etched to reach the piezoelectric crystal layer or any heterogeneous thin film layer. Filler metal is sputtered into the back vias. Before etching the front piezoelectric crystal layer, a surface acoustic wave (SAW) filter pattern can be fabricated on the complete surface of the glass-based heterogeneous integrated wafer with back vias. After etching the piezoelectric crystal layer, the bottom of the filler metal is exposed on the surface of the glass-based heterogeneous integrated wafer. The SAW filter and the filler metal are then interconnected through photolithography, evaporation or sputtering, electroplating, etc. The blind vias can be arranged into a folded inductor, connected to the front device layer through the through-holes. This invention features better device heat dissipation, improved package design and mass production capabilities, higher integration density, and higher device Q-value.

The present invention proposes an isotropic material plate impact positioning method based on a wavenumber domain response function, which belongs to the field of aircraft technology and solves the problems of low positioning accuracy and robustness of existing impact positioning methods. The steps include: calculating the dispersion curve of the guided wave according to the material properties and geometric dimensions of the detected part; selecting a preset frequency range, constructing a wavenumber-angle relationship function, and combining it with the frequency curve to obtain a frequency-angle function; constructing a wavenumber domain response function, and performing Fourier transform on the wavenumber domain response function to obtain a spatial domain response distribution function; mapping the pattern presented by the spatial domain response distribution function into an electrode of a piezoelectric crystal to obtain a directional sensor with a frequency component filtered according to direction; rigidly connecting several directional sensors to the detected part, outputting the 1dB bandwidth of the response signal, and constructing a fan-shaped area for each directional sensor, and using the intersection area of ​​all fan-shaped areas as the positioning result of the impact point.

The invention discloses a surface acoustic wave device and a radio frequency front end module, the surface acoustic wave device comprises a piezoelectric layer, a sound velocity layer and an interdigital electrode, and the interdigital electrode comprises a plurality of electrode fingers. The piezoelectric layer is provided with a first surface and a second surface which are oppositely arranged, the interdigital electrode is arranged on the first surface of the piezoelectric layer, and the sound velocity layer is arranged on the second surface of the piezoelectric layer; sound waves generated when the surface acoustic wave device works comprise surface acoustic waves and body waves; the surface acoustic wave device has a first characteristic depth, and the thickness of the piezoelectric layer is smaller than the first characteristic depth; wherein the first characteristic depth is related to the midline distance between two adjacent electrode fingers of the interdigital electrode, the bulk wave sound velocity of the piezoelectric crystal in the x direction and the working frequency. The sound velocity layer is directly arranged below the piezoelectric layer, the thickness of the piezoelectric layer is limited to be smaller than the first characteristic depth, and the thickness of the piezoelectric layer is reasonably reduced, so that the sound velocity of the surface wave is obviously improved or reduced, and meanwhile, the influence on the effects of other functional layers is avoided.

The invention discloses a surface acoustic wave-based road icing sensor, which comprises a surface acoustic wave icing sensing chip and a signal processing system, and is characterized in that the surface acoustic wave icing sensing chip comprises a piezoelectric crystal, and an input transducer, an output transducer and a waveguide layer which are deposited on the piezoelectric crystal; the signal processing system comprises a signal source, a phase-locked loop and a splitter which are connected in sequence, and further comprises an amplitude discriminator and an A / D converter, and the splitter outputs two paths of signals which are directly connected to the amplitude discriminator respectively and are connected to the amplitude discriminator after passing through the surface acoustic wave icing sensing chip; the amplitude discriminator outputs a comparison result of the two paths of signals to the A / D converter so as to obtain road icing information; real-time monitoring of icing and the thickness of an ice layer is realized by utilizing the acoustic mode change of the surface acoustic waves caused by icing and the mass load effect, so that the road icing sensor disclosed by the invention has the technical effects of low power consumption, fast response and strong anti-interference capability.

The disclosed method of diffusion bonding of a lead zirconate titanate piezoelectric crystal to a metal wear plate, for the fabrication of an ultrasonic transducer operable at high temperatures and able to withstand repeated thermal cycling, comprises depositing noble metal coatings on both bonding surfaces, bringing the surfaces into contact, and heating under pressure at a temperature ranging from 270 to 400° C.

A sensitive unit structure of a piezoelectric-piezoresistive coupled electric field sensor and application, comprising a substrate, a cantilever beam structure is arranged on the substrate, a piezoelectric crystal block is bonded between the lower surface of the cantilever beam structure and the upper surface of the substrate, and a Wheatstone full-bridge structure is arranged on the upper surface of the cantilever beam structure; when the piezoelectric crystal block is subjected to the action of an electric field, the piezoelectric crystal block generates deformation along the Z-axis direction under the action of the inverse piezoelectric effect, so that the cantilever beam structure is deformed; in the Wheatstone full-bridge structure, the resistors arranged at the positions with the maximum stress difference generate deformation under stress, the stress directions of the resistors are opposite, and the resistance value changes are opposite; compared with the commonly used electric field sensor sensitive unit structures such as the electro-optic type and the mechanical type, the present application has the advantages of a larger range, a smaller size, lower power consumption and easy mass production.

The invention relates to a locking type steel wire thread insert vibration test clamp device and a vibration test method, which are suitable for vibration examination of a locking type steel wire thread insert in a free state in an aero-engine. The device comprises a clamp base body, a bolt connecting hole, an O-shaped groove and an induction block. The clamp base body is rigidly connected with the electromagnetic vibration table through a bolt, the O-shaped groove is used for installing a steel wire thread insert test piece, the induction block is made of piezoelectric crystal materials, and when the steel wire thread insert vibrates to reach the set amplitude, the induction block is contacted to generate induction current to drive the induction lamp or the ampere meter to display. The test method comprises seven steps of system connection and preparation, parameter setting and starting, vibration amplitude monitoring, amplitude adjustment, assessment state confirmation, vibration assessment execution and test ending. Through a closed-loop control system formed by an external source signal generator and a laser displacement sensor, single-degree-of-freedom fixed-amplitude vibration in a non-resonance state is realized, the amplitude control is accurate, overload is avoided, parallel testing of multiple test pieces is supported, the test efficiency is improved, the method is closer to actual working conditions, and the method has higher engineering application value.

The invention relates to the technical field of medical equipment, and relates to an output control method and system of a piezoelectric shock wave therapeutic apparatus, and the method comprises the steps: responding to the shock wave therapeutic apparatus to output mechanical waves to a focus area of a patient, and collecting an infrared thermogram of the focus area of the patient; obtaining the maximum value of the gray values of all the pixel points in the infrared thermal image, and obtaining the ratio of the number of the pixel points of which the gray values are greater than a preset threshold value in the infrared thermal image to the number of all the pixel points in the infrared thermal image; calculating a risk scoring coefficient at the current moment; and according to the risk scoring coefficient at the current moment, correcting an input voltage of a piezoelectric crystal in the piezoelectric shock wave therapeutic apparatus at the previous moment so as to determine an input voltage of the piezoelectric crystal at the current moment.

The invention provides a high-order modal test method based on piezoelectric crystal excitation. The high-order modal test method comprises the steps that 1, a piezoelectric vibration exciter is matched through the frequency range of blade simulation; 2, a modal test platform is built, and surface treatment is conducted on a modal test piece; 3, modeling of a three-dimensional laser vibration measurement system is carried out; 4, performing high-frequency excitation and vibration acquisition on the three-dimensional laser vibration measurement system; according to the method, remote high-precision automatic multi-measuring-point arrangement, measured blade three-dimensional model scanning modeling and point-by-point automatic vibration measurement in the blade high-order modal test are completed through the three-dimensional laser Doppler scanning technology, and measurement of modal parameters such as the blade high-order modal shape and the modal frequency is achieved.

The utility model provides a piezoelectric catalysis device which comprises a reactor used for containing reaction liquid to be catalyzed, a cover plate used for covering an opening of the reactor is arranged at the top of the reactor, and a plurality of first supporting pieces used for containing piezoelectric crystal catalysts and a plurality of second supporting pieces used for supporting the cover plate are arranged in the reactor. The first supporting piece is arranged below the second supporting piece, an upper ultrasonic transducer is fixed to the cover plate, a lower ultrasonic transducer is fixed to the lower portion of the reactor, the upper ultrasonic transducer and the lower ultrasonic transducer are both electrically connected with an ultrasonic generator, a temperature measuring piece is fixed in the reactor and connected with the information input end of a controller, and the controller is electrically connected with the controller. And the ultrasonic generator is connected with the information output end of the controller. The piezoelectric catalysis device provided by the utility model provides double sound energy for the piezoelectric crystal catalyst, improves the catalysis effect of the piezoelectric crystal catalyst and promotes the reaction.

The invention relates to the technical field of oil and gas field development, and discloses a linkage type intelligent opening system for intelligent fracturing sliding bushings and a control method thereof.The system comprises the multiple intelligent fracturing sliding bushings internally provided with multi-dimensional coding response units; the multi-dimensional coding response unit comprises a micro piezoelectric resonator array, the micro piezoelectric resonator array is composed of a plurality of piezoelectric crystals with inherent acoustic resonant frequencies, and acoustic fingerprint codes of the intelligent fracturing sliding sleeve are formed by the set combination of the inherent acoustic resonant frequencies of the piezoelectric crystals; and the micro magnetostriction exciter has the optimal response frequency sensitive to the alternating magnetic field with the set frequency, and the optimal response frequency forms a magnetic field response code of the intelligent fracturing sliding sleeve. By compounding the acoustic fingerprint codes and the magnetic field response codes, opening of the intelligent fracturing sliding sleeve does not respond to interference of a single underground field source, such as sound waves or magnetic field fluctuation without specific codes, so that the unexpected opening probability is reduced, and the specificity of target selection is improved.

This utility model relates to a piezoelectric vibration sensor with an adjustable counterweight position, belonging to the technical field of piezoelectric vibration sensors. The piezoelectric vibration sensor with an adjustable counterweight position includes: a housing, a base at the bottom of the housing, and a mounting component mounted on the base. The adjustment mechanism includes a driving block disposed inside the housing, a mass block disposed inside the driving block, and a threaded rod for adjusting the position of the driving block disposed inside the housing. By setting the adjustment mechanism, the position of the counterweight can be adjusted inside the housing, allowing the sensor to be optimized according to different vibration frequencies, improving its sensitivity and detection accuracy. By adjusting the position of the counterweight, it can be ensured to better cooperate with the piezoelectric crystal, thereby increasing the output charge of the sensor. This improvement allows the sensor to maintain relatively accurate measurement results under different vibration environments.

The present application is directed to systems and processes for generating electrical power from piezoelectric elements. One exemplary implementation is a system that includes a rotor, a piston, multiple holders, and a plurality of piezoelectric elements. The holders are disposed in a consecutive arrangement that extends radially away from an outer circumferential surface of the rotor, and each holder has one or more openings defined therethrough. The piezoelectric elements housed in each holder are disposed in respective openings of the corresponding holder. The piezoelectric elements corresponding to an innermost one of the holders is mechanically coupled to the outer circumferential surface of the rotor via the piston. And, an electrical contact is disposed between each pair of adjacent holders such that the piezoelectric crystals corresponding to each holder are connected in a parallel circuit.

The application discloses a surface acoustic wave device and a radio frequency front-end module. The surface acoustic wave device comprises a piezoelectric layer, a sound velocity layer and an interdigital electrode, wherein the interdigital electrode comprises a plurality of electrode fingers. The piezoelectric layer has a first surface and a second surface arranged oppositely, the interdigital electrode is arranged on the first surface of the piezoelectric layer, and the sound velocity layer is arranged on the second surface of the piezoelectric layer. The sound wave of the surface acoustic wave device in operation comprises a surface acoustic wave and a bulk wave. The surface acoustic wave device has a first characteristic depth, and the thickness of the piezoelectric layer is less than the first characteristic depth. The first characteristic depth is related to the center line spacing of two adjacent electrode fingers of the interdigital electrode, the bulk wave sound velocity of the piezoelectric crystal along the x direction and the working frequency. By arranging the sound velocity layer directly below the piezoelectric layer and limiting the thickness of the piezoelectric layer to be less than the first characteristic depth, the thickness of the piezoelectric layer is reasonably thinned, the surface wave sound velocity is obviously improved or decreased, and the influence on other functional layers is avoided.

The present application relates to a surface acoustic wave device, a radio-frequency front-end module, and an electronic device. The surface acoustic wave device comprises a piezoelectric layer, and an interdigital electrode, which is provided on a first surface of the piezoelectric layer. The interdigital electrode comprises a plurality of electrode fingers. During the operation of the surface acoustic wave device, acoustic waves comprise surface acoustic waves and bulk acoustic waves, wherein the propagation direction of the surface acoustic waves is an X direction. A first characteristic thickness of the surface acoustic wave device is Ty, and the thickness of the piezoelectric layer is Dy, and the thickness of the piezoelectric layer and the first characteristic thickness meet the following conditions [equation I], wherein the piezoelectric layer comprises a piezoelectric crystal, and the value of the first characteristic thickness is determined on the basis of the centerline spacing between two adjacent electrode fingers, the bulk acoustic wave velocity of the piezoelectric crystal in the X direction, and an operating frequency. The thickness of the piezoelectric layer is defined by means of a first characteristic thickness, thereby preventing the acoustic functions of other structures from being affected by the excessive thickness of the piezoelectric layer, and thus improving the operation performance of the surface acoustic wave device.

The invention relates to the technical field of optical detection, and provides a wavefront error detection method of a phase-shifting interferometer, which realizes phase shifting through voltage regulation and control of an electro-optical crystal, replaces a mechanical driving mode of a traditional piezoelectric crystal, avoids the problems of shifting distance drift and linearity distortion caused by internal heating of the electro-optical crystal, and improves the detection accuracy of the wavefront error of the phase-shifting interferometer. An error source caused by mechanical motion is eliminated in principle, so that the phase shifting process is more stable, and the detection repeatability is improved; by adjusting the optical path difference of a coherent optical path, the optical path difference of reflected light of the first semi-transparent and semi-reflecting mirror and the first beam expanding lens is only enabled to be smaller than the coherent length of short coherent light, and only target interference fringes are ensured to be generated; meanwhile, the optical path difference of other non-target optical paths exceeds the coherence length, stray light interference is effectively eliminated, the signal-to-noise ratio and purity of an interferogram are improved, and reliable data are provided for wavefront error calculation.

The invention discloses a piezoelectric crystal grinding control system based on a frequency testing technology. Comprising the steps that a hardware collection module collects original resonance frequency signals, vibration intensity and grinding head working parameters; the frequency test compensation module performs separation compensation on vibration interference and outputs accurate resonant frequency and change rate thereof; a dynamic mapping model is arranged in the dynamic mapping control module, the accurate resonance frequency, the change rate and the vibration intensity serve as input, the rotating speed, the pressure and the feeding amount of a grinding head are output, dynamic correction and advanced pre-judgment are conducted on the output through a vibration working condition correction unit and a frequency drift advanced pre-judgment unit, and a grinding parameter instruction is generated; the execution driving module drives the grinding head to adjust working parameters according to the instruction; and the closed-loop self-calibration module corrects the compensation coefficient and the model weight according to the actual frequency convergence effect. The full-link closed-loop precise control of the grinding process is realized, the vibration interference is effectively inhibited, and the frequency test precision and the processing consistency are improved.

The invention provides a surface acoustic wave device, which is characterized in that the surface acoustic wave device is used for opening a blood brain barrier, and comprises a piezoelectric crystal; the two interdigital transducers are arranged on the surface of the piezoelectric crystal; the transfer chamber is arranged on the surface of the piezoelectric crystal and is positioned between the two interdigital transducers; wherein the transfer chamber is used for placing a blood-brain barrier model or a blood-brain barrier part, the two interdigital transducers are used for driving the piezoelectric crystal to vibrate so as to transmit surface acoustic waves in the blood-brain barrier model or the blood-brain barrier part, and the surface acoustic waves act on a blood-brain barrier so as to open the blood-brain barrier. The device provided by the invention can realize reversible opening of the blood-brain barrier and promote the application prospect of drug delivery of the central nervous system.

The present application relates to the technical field of piezoelectric crystal, and particularly relates to a roughening processing method for the back surface of an ultrathin lithium tantalate wafer, which comprises the following steps: a) protecting the front surface of the lithium tantalate wafer by pasting a film; b) heating and sandblasting abrasive, and baking the sandblasting abrasive; c) starting the rotation of a sandblasting platform, adjusting the distance between the sandblasting gun and the lithium tantalate wafer, adjusting the sandblasting pressure to 0.2-0.3 Mpa, and performing first roughening processing on the back surface of the wafer; d) after the first roughening processing is completed, removing the sandblasting particle residues attached to the surface of the wafer, readjusting the sandblasting pressure to 0.1-0.15 Mpa, and performing second roughening processing on the back surface of the wafer; e) after the second roughening processing is completed, immersing the wafer in a mixed solution tank of hydrofluoric acid and nitric acid, then immersing the wafer in a warm water tank for ultrasonic cleaning, then immersing the wafer in a normal temperature tank for ultrasonic cleaning, and finally immersing the wafer in an overflow tank to complete wafer cleaning.

The invention discloses a large-span truss and a safety monitoring system thereof, and relates to the technical field of bridge engineering, the large-span truss comprises a plurality of truss single bodies which are arranged and combined mutually, the bottoms of the truss single bodies are connected with bases, each truss single body comprises an upper chord member and a lower chord member which are correspondingly arranged, and side vertical rods are correspondingly fixed to the two ends of each chord member through bolts; a middle vertical rod is fixed to the middle of the chord member through a bolt, an outer side gusset plate is fixedly installed on one side of each side vertical rod, side inclined rods are correspondingly installed at the upper end and the lower end of each outer side gusset plate, one ends of the side inclined rods are fixed to the chord member, middle gusset plates are correspondingly installed on the two sides of the middle vertical rod, and the middle gusset plates are fixedly installed on the two sides of the middle vertical rod. Middle inclined rods are fixedly installed on the periphery of the middle gusset plate, one end of each middle inclined rod is fixed to the chord member, and the safety monitoring system comprises four piezoelectric crystals installed on the side wall of the middle gusset plate.

The invention discloses a detection device with small strain monitoring and a piezoelectric crystal and a testing method of the detection device, and aims to solve the problem that multi-scale real-time observation and accurate monitoring are difficult to carry out in a multi-gas hydrate replacement process in the prior art. The device is used for detecting the replacement efficiency and the micromechanical rigidity of the hydrate in different sediment mineral environments in a reaction kettle, during use, a hydrate replacement experiment is carried out between soil particles or ore sheets, and the change of the resistivity and the rigidity of the hydrate in the replacement process under the micro-micro scale is recorded in detail; the bending element performs real-time monitoring and effective analysis recording on soil body small strain in the replacement process so as to reflect soil body void ratio change, pore pressure change and structural damage of fine-grained soil and characterize important parameters of soil body deformation and dynamic characteristics. Powerful technical support and experimental means are provided for the research on the macro-fine-micro phenomenon of hydrate replacement in different simulated sediment geological environments under laboratory conditions.

The invention relates to a surface acoustic wave device, a radio frequency front-end module and electronic equipment. The surface acoustic wave device comprises a piezoelectric layer and an interdigital electrode arranged on the first surface of the piezoelectric layer, wherein the interdigital electrode comprises a plurality of electrode fingers; when the surface acoustic wave device works, acoustic waves comprise surface acoustic waves and bulk waves, and the propagation direction of the surface acoustic waves is the X direction; the first characteristic thickness of the surface acoustic wave device is the thickness of the piezoelectric layer, and the thickness of the piezoelectric layer and the first characteristic thickness meet the condition; wherein the piezoelectric layer comprises a piezoelectric crystal, and the size of the first characteristic thickness is determined according to the midline distance between two adjacent electrode fingers, the bulk wave sound velocity of the piezoelectric crystal in the X direction and the working frequency of the piezoelectric crystal. The thickness of the piezoelectric layer is limited through the first characteristic thickness, so that the influence on the acoustic function of other structures due to the too thick piezoelectric layer is avoided, and the working performance of the surface acoustic wave device is improved.

The present application is directed to systems and processes for generating electrical power from piezoelectric elements. One exemplary implementation is a system that includes a rotor, a piston, multiple holders, and a plurality of piezoelectric elements. The holders are disposed in a consecutive arrangement that extends radially away from an outer circumferential surface of the rotor, and each holder has one or more openings defined therethrough. The piezoelectric elements housed in each holder are disposed in respective openings of the corresponding holder. The piezoelectric elements corresponding to an innermost one of the holders is mechanically coupled to the outer circumferential surface of the rotor via the piston. And, an electrical contact is disposed between each pair of adjacent holders such that the piezoelectric crystals corresponding to each holder are connected in a parallel circuit.

The application discloses a kind of based on sealing self-checking stop valve, it is related to stop valve technical field.The application utilizes the displacement when lower valve flap closes, automatically opens sealing test groove, and the leakage liquid is guided and collected, is driven detection ring by leakage liquid and moves upwards, to drive detection block extrusion transmission block, finally triggers piezoelectric crystal, converts leakage physical quantity into quantifiable electric signal, realizes the purpose of sealing self-checking.Utilize the design that valve flap assembly opens, lower valve flap automatically rebounds, drives drainage ring and sealing test groove inlay, extrudes the leakage liquid in sealing test groove, reaches the effect of drainage.Utilize the pressure when valve flap assembly closes, make lower valve flap and upper valve flap close, extrude airbag ring, airbag ring generates one-way expansion and carries out secondary sealing to intercepting port, in combination with the primary seal between upper valve flap and lower valve flap and intercepting port, realize the effect of multiple sealing to intercepting port.