122 results about "Cavity resonance" patented technology

An example apparatus, method, and system for determining a characteristic of a target gas in a fluid sample is provided. In some embodiments, the example apparatus includes a frequency comb illumination source configured to emit pulsed light having a plurality of frequency comb wavelengths. The apparatus also includes an optical cavity containing a fluid sample and exhibiting a plurality of cavity resonance modes. A frequency comb wavelength of the plurality of frequency comb wavelengths associated with the frequency comb illumination source is configured to align with a cavity resonance mode of the plurality of cavity resonance modes. A characteristic of the fluid sample is determined based on one or more optical characteristics of a transmitted light passing through the fluid sample within the optical cavity.

The invention discloses a noise reduction frequency band adjustable acoustic liner device based on a folding structure, which comprises a perforated panel, a honeycomb sandwich and a back plate, the honeycomb sandwich is composed of a plurality of honeycomb single cavities arranged in an array, the lower end of the honeycomb sandwich is fixed on the back plate, the perforated panel covers the upper end of the honeycomb sandwich, the perforated panel is provided with a plurality of panel through holes, and the panel through holes are communicated with the honeycomb sandwich. The panel penetrating holes are communicated with the honeycomb single cavities, folding structures are placed at the bottoms of the honeycomb single cavities, the folding structures can adjust the size and height of the folding structures through folding or stretching, then the cavity size of the honeycomb single cavities is changed, and the resonant frequency of the honeycomb single cavities is adjusted. Resonant frequency deviation of the resonant cavity is achieved through the folding structure, and the effect that the sound absorption frequency of the acoustic liner is adjustable is achieved. Meanwhile, a telescopic motor is combined with an adjusting plate and a pull rod, synchronous adjustment of all folding structures is achieved, the number of adopted assemblies is small, the structure is simple, and the good engineering application value is achieved.

The technology described herein is directed towards a metasurface arranged with unit cells for narrowband sound absorption, in which the unit cells are based on Helmholtz resonators that can have their resonant frequencies adjusted via MEMS actuators. A sound absorbing unit-cell is designed and constructed based on a general resonance frequency, and includes a neck portion and air chamber dimensioned to resonate close to the desired resonance frequency and thereby inverse phase cancel corresponding narrowband frequencies of incoming sound waves. A moveable partition in the resonators, controlled by MEMS actuators, facilitates changing of the resonators' air cavity dimensions, to adjust the resonant frequencies to cancel acoustic waves of different frequencies corresponding to noise, which can change over time. The unit cells can be distributed as part of a metasurface, which can be positioned proximate to a noise source to phase cancel the noise.

The invention relates to a semi-active pressure-resistant low-frequency sound absorption covering layer containing a piezoelectric composite material. The semi-active pressure-resistant low-frequency sound-absorbing covering layer containing the piezoelectric composite material structurally comprises a surface protecting layer which is arranged on the outermost side of the covering layer and converts sound energy into heat energy through a damping effect; the piezoelectric composite material layer is arranged on the inner side of the surface protection layer, converts sound energy into electric energy through a direct piezoelectric effect, and dissipates the electric energy through a shunt branch; the cavity layer is arranged on the inner side of the piezoelectric composite material layer and absorbs sound through a cavity resonance effect, waveform conversion and a damping effect; the substrate layer is arranged on the inner side of the cavity layer to seal the cavity layer so as to absorb sound with a damping effect; wherein the composite material layer is electrically connected with an external shunt branch, and the shunt branch is formed by connecting a negative capacitance element, a resistance element and an inductance element in series.

The invention relates to an air tightness detection device and method based on resonance frequency shift of a resonant cavity, belongs to the technical field of air tightness detection, and aims to solve the problems of high equipment cost, complex operation, low efficiency and difficulty in realizing multi-parameter quantitative detection in the traditional air tightness detection technology. High-purity helium with rated pressure is filled into a to-be-detected piece through a gas compressor, the to-be-detected piece is placed in a volume-adjustable detection container after pressure maintaining, and leaked helium is pumped by a vacuum pump to flow into a resonant cavity; resonance frequency deviation caused by helium concentration changes is monitored, temperature and humidity calibration data are combined, three air tightness parameters including the leakage rate (Pa.m / s), the leakage speed (mL / min) and the leakage pressure (Pa) are calculated in real time through a microcontroller, and the air tightness grade of a to-be-detected piece is output according to the air tightness detection standard. According to the device, the volume of the detection container is adaptively adjusted through the sliding rail, and the detection efficiency and adaptability can be remarkably improved by combining frequency mixing excitation and a rapid frequency calibration technology; according to the method, resonance frequency shift-helium concentration-airtightness parameters are converted, and high-precision, multi-parameter and integrated airtightness detection is realized. The invention has the advantages of fast response speed, strong anti-interference performance, low cost and the like, is suitable for fast automatic leak detection of industrial products such as sealing devices, pressure containers and the like, and provides a new scheme for trace gas detection and gas tightness grading.

The invention provides a gas-liquid hole cavity characteristic frequency checking method, device and equipment, and the method comprises the steps: predicting a shear oscillation frequency interval of a gas-liquid hole cavity according to the prediction range of the environment flow velocity outside the gas-liquid hole cavity; predicting a structural inherent frequency interval, a liquid cavity modal frequency interval, a gas cavity modal frequency interval and a sloshing frequency interval of the gas-liquid hole cavity by referring to a prediction range of a gas volume ratio in the gas-liquid hole cavity; the piston frequency interval of the gas-liquid hole cavity is predicted by referring to the prediction range of the gas volume ratio in the gas-liquid hole cavity and the prediction range of the environment pressure outside the gas-liquid hole cavity; and checking whether each of the structure inherent frequency interval, the liquid cavity modal frequency interval, the air cavity modal frequency interval, the sloshing frequency interval and the piston frequency interval meets the safety margin requirement relative to the shear oscillation frequency interval or not. According to the invention, the characteristic frequency of the gas-liquid pore cavity is checked, so that the problem of pore cavity resonance of a ship under common working conditions is avoided.

A VCSEL laser has one or more active regions with quantum wells and barriers. The active regions are surrounded by one or more p-n junctions. The one or more active regions can include a selected shape structure, as well as one or more tunnel junctions (TJ). One or more apertures are provided with the selected shape structure. One or more buried tunnel junctions (BTJ) or oxide confine apertures, additional TJ's, planar structures and or additional BTJ's created during a regrowth process that is independent of a first growth process are provided. A VCSEL output is determined in response to a monitoring application of the VCSEL. The VCSEL has an HCG grating and a bottom DBR. A mesa is located within either at a lower mirror layers or an upper mirror layers. The mesa has a lateral dimension that is less than a lateral dimension of the one or more lower mirror layers or the one or more upper mirror layers, respectively. The mesa is configured such that a first vertical cavity, which includes the mesa, has a cavity resonance that is different from a cavity resonance for a second vertical cavity that does not include the mesa and which is adjacent the first vertical cavity. The HCG tunable VCSEL has optical confinement created with step index and regrowth.

The invention discloses a bridge type structure micro-bolometer based on a Mn-Co-Ni-O thin film and a preparation method of the bridge type structure micro-bolometer. According to the method, a Mn-Co-Ni-O post-high-temperature annealing process is considered, annealing is carried out on the suspension structure where the sacrificial layer is released, an organic sacrificial layer material release process is compatible, and the problem that cracks are generated in Mn-Co-Ni-O manufacturing due to tension and compression stress of materials of all layers of a substrate at a high temperature is minimized through annealing of the suspension structure; a bridge type structure based on Mn-Co-Ni-O is provided, and the limitation that traditional Mn-Co-Ni-O can only adopt an organic sacrificial layer and back digging to carry out thermal isolation design is eliminated; the F-P resonant cavity resonance absorption structure based on Mn-Co-Ni-O is successfully manufactured, traditional self-absorption based on a Mn-Co-Ni-O thick film is replaced, and the heat capacity of a device is reduced while absorption is enhanced by adopting a thin film optical structure; the applicable scene of the invention can be expanded to all cantilever or film-suspending micro-nano devices, such as inertial sensors, pressure sensors, chemical / biological sensors and optical detectors of other principles.

The invention relates to a method for rapidly measuring the resonant frequency of a resonant cavity based on frequency spectrum polynomial fitting, and belongs to the technical field of acoustic / optical measurement. The objective of the invention is to solve the problems of tedious steps, low efficiency, long time, poor stability and the like of a resonant cavity or resonant photoacoustic cavity resonant frequency measurement method. According to the method, the frequency spectrum of the resonant cavity is obtained through frequency mixing excitation, the frequency is obtained after curve fitting is conducted on frequency spectrum data points through a frequency spectrum polynomial fitting algorithm, and then resonant frequency measurement of the resonant cavity is achieved. According to the method, the measurement time of the resonant frequency of the resonant cavity is remarkably shortened, the measurement steps are simplified, and the measurement precision is improved; meanwhile, the resonance frequency is solved through frequency spectrum polynomial fitting, data noise interference can be effectively reduced, and the method has higher robustness. All frequency signals within the resonant frequency drift range are transmitted at a time through frequency mixing excitation, one-by-one scanning is not needed, and therefore the method has the advantages of being good in real-time performance, high in response speed, high in precision and the like, and is suitable for rapid frequency calibration and real-time monitoring in the fields of acoustic resonators, resonant photoacoustic spectra and the like. And a novel method for measuring the resonant frequency is provided for the fields of high-sensitivity resonance photoacoustic spectroscopy, acoustic trace gas detection and the like.

The invention relates to the technical field of microwave communication, in particular to a stepped transmission band line shielding cavity resonance suppression structure, which comprises a shielding shell provided with an open accommodating cavity; the transmission band line is arranged in the accommodating cavity of the shielding shell; and the shielding cover plate is used for covering the shielding shell, and a convex block is integrally formed on the lower surface of the shielding cover plate. The bump structure is integrally formed on the shielding cover plate, so that resonance suppression of the shielding cavity is realized, and the influence of cavity resonance on the performance of the transmission band line can be reduced or even eliminated through introduction of the bump structure.

The invention discloses a visible-infrared transparent broadband microwave absorption light window based on multi-resonance, and belongs to the field of optical transparent electromagnetic shielding and microwave absorption. The light window is composed of a metal microstructure resonance layer, a transparent dielectric layer and a metal mesh layer which are sequentially stacked from top to bottom. The metal microstructure resonance layer can generate electric resonance with double resonant frequencies due to the existence of pores and patches, and the metal microstructure resonance layer, the transparent dielectric layer and the metal mesh layer are utilized to form a Fabry-Perot cavity to generate Fabry-Perot cavity resonance. Broadband microwave absorption is formed under the combined action of electric resonance with double resonant frequencies and Fabry-Perot cavity resonance. In addition, the metal microstructure resonance layer and the metal mesh layer have extremely low metal duty ratios, and visible-infrared broadband high light transmission can be achieved. The application range of the optical transparent broadband microwave absorption technology is expanded, and the optical transparent broadband microwave absorption device has the advantages of corrosion resistance, wide absorption bandwidth, visible-infrared broadband light transmission and the like.

The present invention discloses an ultra-narrowband absorber tunable from visible to mid-infrared, and its structure includes a substrate, a bottom Bragg reflector, a resonant cavity layer, a lower electrode, a dielectric spacer layer, an upper electrode, a bilayer graphene structure capable of mutual electrostatic gating, and a top Bragg reflector. The absorber is based on Fabry-Perot cavity resonance to form a resonance mode within the resonant cavity layer between the bottom and top Bragg reflectors. The radiation loss rate of this resonance mode is mainly determined by the constituent components, the number of periods of the Bragg reflector, and the Fermi level of graphene together, while the absorption loss rate is determined by the Fermi level of graphene. The bandwidth of the resonance mode is jointly determined by the magnitudes of the radiation loss rate and the absorption loss rate. By constructing a Bragg reflector with appropriate components and number of periods and regulating the Fermi level of graphene to make the system reach critical coupling, an ultra-narrowband perfect absorption tunable from visible to mid-infrared can be achieved.

The invention relates to an acoustic insulation panel (1) based on Helmholtz single-cavity resonators, designed to effectively attenuate low-frequency noise generated by industrial equipment. The panel (1) is formed by a front wall (2) and a rear wall (3), both U-shaped, enclosing a hollow space (4) that acts as a resonator cavity. The shorter sides (2', 3') of these walls are folded inwards, forming channels that function as inlets (5) to the resonator. Furthermore, an acoustic insulation system composed of several of these panels (1) is described, in which the panels are arranged so as to allow both ventilation and noise attenuation. The associated acoustic insulation method consists of facing the resonators to maximize noise absorption at specific frequencies, ensuring a laminar air flow that improves the efficiency of the system without the need for large volumes or additional silencers.

The invention provides a three-cavity resonance horse head string instrument and belongs to the horse head string technical field, the three-cavity resonance horse head string instrument comprises an instrument box, a rod body assembly and strings, the instrument box is provided with a box body cavity, an instrument head, an instrument neck and an instrument rod are integrally arranged from top to bottom, the bottom of the instrument rod is fixed in the instrument box, the instrument head is internally provided with a head cavity, the instrument head is provided with ear holes, eye holes and nostrils, and the head cavity is provided with a cavity. The ear holes, the eye holes and the nostril are simultaneously communicated with the head cavity and the outside, a chest cavity is arranged at the lower position in the neck, the head cavity, the chest cavity and the box cavity are sequentially communicated, and the strings are arranged between the box and the rod. Through the communication arrangement of the head cavity, the chest cavity and the box body cavity, after the three cavities resonate, the audio amplitude is balanced, the sound is bright, and meanwhile, the high-frequency volume can be multiplied, so that no matter high-pitch strings or low-pitch strings, the audio frequency in a high-pitch area is rich, the playing is easy, the soft high-pitch melody can be made, and the expressive force of the piano sound is enhanced.

This application provides a long-wave infrared light absorber based on phase change materials and MIM structures, belonging to the field of integrated photonic devices. The absorber includes a reflective layer, a double dielectric layer, and a metasurface layer. The metasurface layer allows light waves to enter the double dielectric layer through diffraction. The reflective layer and the metasurface layer form two reflective surfaces, allowing the light waves to undergo multiple reflections and achieve FP-cavity resonance. When the metasurface layer is crystalline and the polarization state of the light wave is not parallel to that of the metasurface layer, both the reflective layer and the metasurface layer possess metallic properties, enabling plasmon resonance when the frequency of the incident light wave matches the collective oscillation frequency of free electrons in the metal. Both FP-cavity resonance and plasmon resonance lead to the localization and enhancement of the electromagnetic field within the double dielectric layer, thereby enhancing the absorption of light waves. This application achieves reversible switching between two light wave absorption states by changing the phase state of the phase change material.

The present invention provides an on-chip photonic circuit for generation of a polarization-entangled photon-pair state by utilizing the optical nonlinearities in a novel configuration comprising dual micro-resonators, with nearly degenerate transverse-electric- and transverse-magnetic-polarized cavity resonances for the two resonators coupled in series to a common bus waveguide, wherein, the pump laser and the generated signal and idle photons can be coupled in and out the photonic circuit.

The invention discloses a high-power micro-cavity optical frequency comb generation device and method, and solves the problems that an existing optical frequency comb system needs to adopt a high-speed tunable laser to carry out precise scanning locking on micro-cavity resonance, or depends on distributed feedback type semiconductor laser with extremely narrow linewidth to carry out optical injection feedback on an ultra-high-quality micro-cavity; in order to solve the problems of complex system structure and operation due to the fact that the existing optical frequency comb has the advantages of high repetition frequency, high comb power and wide spectral range, pumping is carried out by a pumping unit, optical frequency comb generation and synchronous power amplification are carried out through an active gain microcavity, and the channel interval (100GHz) of the optical frequency comb meets the international communication standard. The power of a single comb tooth reaches a hundred mu W level and is improved by 2-3 orders of magnitude compared with a common Kerr microcavity optical frequency comb scheme (a typical value is a hundred nW level), so that weak signal power amplification is not needed, and the Kerr microcavity optical frequency comb has important application value in the field of optical communication.

The present invention discloses a sound generating device and an electronic device having the same. The sound generating device includes: a housing, the housing includes a front cover, a middle case and a lower case, the middle case is provided on one side of the lower case, and the front cover is provided on the side of the middle case away from the lower case; a diaphragm assembly, the diaphragm assembly is provided on the side of the lower case close to the middle case, the outer periphery of the diaphragm assembly is fixed to the middle case, and the front cover, the middle case and the diaphragm assembly jointly define a front sound cavity of the sound generating device, and the front cover is provided with a sound outlet hole communicating with the front sound cavity; wherein, at least part of the front cover and / or the middle case is a waterproof and breathable part containing an organic aerogel material, the waterproof and breathable part has a breathable channel therein, the outer surface of the waterproof and breathable part has pores communicating with the breathable channel, the pore diameter of the pores is 0.05μm to 20μm, and the porosity of the waterproof and breathable part is 10% to 70%. According to the sound generating device of the present invention, the provided waterproof and breathable part can play a role in waterproofing and breathing, balancing the pressure difference between the front and rear sound cavities, reducing cavity resonance and distortion on the premise of meeting the waterproof effect.

This invention discloses a centrifugal fan structure, a motor, and an air conditioner using the same. The centrifugal fan structure, used in an air conditioner, includes a first mounting plate, a second mounting plate, fan blades, and a hub. One end of the fan blades is mounted on the first mounting plate, and the other end is mounted on the second mounting plate. The hub is located on the second mounting plate and forms a cavity between it and the bottom plate of the air conditioner housing. A silencing hole is provided on the hub, and the silencing hole communicates with the cavity. First, this invention uses the silencing hole to disrupt the nearly sealed cavity formed by the hub and the second mounting plate, reducing cavity resonance noise. Second, the silencing hole on the hub can improve the cavity mode of the enclosed space, avoiding resonance excitation in low-speed spaces, thereby solving the vibration and noise problem of the centrifugal fan structure.

The invention provides a low-cavity noise tire, which relates to the field of tire noise reduction, and comprises a tire body and a plurality of cavity resonance energy absorption systems, the plurality of cavity resonance energy absorption systems are used for absorbing vibration kinetic energy generated in the cavities due to tire rotation; the cavity resonance energy absorption system comprises a cavity resonance energy absorption device and a connecting piece, and the two sides of the connecting piece are glued to the cavity resonance energy absorption device and the tire body respectively. The cavity resonance energy absorption system with a certain size is reasonably arranged to eliminate cavity resonance generated in the tire, kinetic energy generated by the cavity resonance is converted into heat energy, then the heat energy is dissipated in a heat radiation mode, finally, the cavity resonance noise generated in the high-speed rotation process of the tire is reduced, and the service life of the tire is prolonged. And the driving experience is optimized.

The application discloses an underwater sound absorption superstructure with double-cavity resonance, which comprises a cavity, two embedded necks and a sandwich layer. The cavity is a rectangular cavity, the sandwich layer is vertically arranged in the cavity and divides the cavity into a first chamber and a second chamber which are arranged in left and right sides, and a through hole is formed in the upper surface of the first chamber and the second chamber; the two embedded necks are hollow straight pipes, respectively penetrating the through holes in the upper surfaces of the first chamber and the second chamber to enter the cavity, so that the first chamber and the second chamber are communicated with the outside. The application utilizes Helmholtz resonance sound absorption, the first chamber and the second chamber of the cavity are connected in parallel through the two embedded necks and connected in series through the holes or gaps of the sandwich layer, so that the sound absorption of the application is different from the classical Helmholtz sound absorption, and the sound absorption is characterized by the coupling of the resonance frequencies of the two single chambers, the sound absorption with a wide frequency is formed, and the wide-frequency sound absorption is realized. The deformation loss of the sandwich layer is derived from the sound absorption mechanism of the pressure difference between the two chambers, so that the superstructure is still effective at high hydrostatic pressure, and the loss effect is increased.

The application discloses a kind of hollow degree and grain fullness of pepper multi-dimensional acoustic online monitoring method and system, it is related to agricultural product quality detection technical field, method includes: by reticular conveyor belt makes the uniform speed of the pepper monomer to be measured in sound insulation shielding channel movement;Utilize air coupling ultrasonic emission probe to the pepper monomer to be measured directional emission ultrasonic wave, utilize transmission wave receiving probe to capture transmission wave after penetrating the pepper, simultaneously utilize micro sound emission sensor to capture the micro sound emission signal of the pepper;Extract the cavity resonance frequency offset of transmission wave and sound energy attenuation coefficient, carry out band energy extraction to the micro sound emission signal to calculate sound energy entropy;After multi-dimensional acoustic characteristics are standardized respectively, as multi-dimensional feature vector, input into the support vector regression model that is trained in advance, output the hollow and fullness comprehensive evaluation index of the pepper monomer to be measured.This scheme can reduce detection cost, no radiation and can accurately penetrate epidermis to obtain internal grain real state.

The present application relates to the technical field of resonant frequency control, and particularly relates to a whispering gallery mode microcavity resonant frequency regulation method and system. The present application analyzes resonant frequencies, temperature data and resonant wavelength movement amounts at different monitoring moments, and obtains coupling influence degrees at each monitoring moment; according to resonant frequency distributions in a time neighborhood range of each monitoring moment, it is judged whether the time neighborhood range needs to be extended; if so, a target function of resonant frequency change rate is constructed in combination with a corresponding preset time extension amount; according to change trends of the preset time extension amounts in the time neighborhood ranges before and after the moment, and the coupling influence degree distributions of different monitoring moments in the preset time extension amounts, a restriction condition of the target function is constructed, and the preset time extension amount is obtained; and the regulation of the microcavity resonant frequency is realized. The present application obtains a suitable heating duration in the heat reflux regulation process, and improves the accuracy of the resonant frequency regulation.

An electronic device provided by the present invention comprises a shell with an accommodating cavity and a sound production monomer arranged in the accommodating cavity, the sound production monomer has a first side and a second side which are opposite to each other along the vibration direction of a vibration system, and a front cavity is formed between the first side of a first vibrating diaphragm and the shell. A rear cavity is formed between the second side of the second vibrating diaphragm and the shell, and the front cavity and the rear cavity are isolated from each other; a Helmholtz resonance cavity structure is arranged in the front cavity, the Helmholtz resonance cavity structure comprises a Helmholtz resonance cavity body and a Helmholtz resonance cavity airflow channel communicated with the Helmholtz resonance cavity body, and sound waves of the front cavity enter the Helmholtz resonance cavity body through the Helmholtz resonance cavity airflow channel. By using the electronic equipment, the problems that the front cavity in the existing electronic equipment resonates, the sensitivity generates a formant, and the sound is easy to be sharp and harsh can be solved.

Systems and methods for performing fault-tolerant quantum operations for a four-legged cat code are provided. A quantum system includes an auxiliary qubit dispersively coupled to a first logical qubit, and the quantum system can be operated at least in part by generating and applying a first drive waveform to the auxiliary qubit, the first drive waveform including a first comb of pi pulses having selective frequencies corresponding to a first selection of even and odd cavity resonance frequencies of the first logical qubit; and reading out a state of the auxiliary qubit.

This invention discloses a noise reduction device and a wheel, including a housing and a control body disposed within the housing. The housing contains a chamber and an opening. The control body includes a rotating body and a rotating shaft. Specifically, the rotating shaft is coaxially connected to the end of the rotating body, which is disposed within the chamber. A baffle is provided on the outer wall of the rotating body. A resonant cavity is formed between the baffle, the outer wall of the rotating body, and the inner wall of the chamber. The resonant cavity communicates with the opening, and the size of the opening is the same as the size of the resonant cavity. Thus, the resonant cavity forms a quarter-wavelength tube. Therefore, this application converts the change in the axial length of the quarter-wavelength tube into a change in the arc length in space. While maintaining the same spatial volume, it can significantly change the length of the quarter-wavelength tube, which is beneficial for changing the noise reduction frequency of the noise reduction device.

An example apparatus, method, and system for determining a characteristic of a target gas in a fluid sample is provided. In some embodiments, the example apparatus includes a frequency comb illumination source configured to emit pulsed light having a plurality of frequency comb wavelengths. The apparatus also includes an optical cavity containing a fluid sample and exhibiting a plurality of cavity resonance modes. A frequency comb wavelength of the plurality of frequency comb wavelengths associated with the frequency comb illumination source is configured to align with a cavity resonance mode of the plurality of cavity resonance modes. A characteristic of the fluid sample is determined based on one or more optical characteristics of a transmitted light passing through the fluid sample within the optical cavity.

Exemplary devices, methods, and systems are provided for determining characteristics of a target gas in a fluid sample. In some embodiments, the example apparatus includes a frequency comb illumination source configured to emit pulsed light having a plurality of frequency comb wavelengths. The device also includes an optical cavity containing the fluid sample and exhibiting a plurality of cavity resonance modes. A frequency comb wavelength of the plurality of frequency comb wavelengths associated with the frequency comb illumination source is configured to align with a cavity resonance mode of the plurality of cavity resonance modes. A characteristic of the fluid sample is determined based on one or more optical characteristics of transmitted light passing through the fluid sample within the optical cavity.

The invention relates to the technical field of electrical equipment fault diagnosis and evaluation, and discloses a method and device for measuring SF6 decomposition product gas through a multi-cavity resonance photoacoustic spectrometry. The device comprises an infrared light source and a photoacoustic spectrum resonant cavity, the laser capable of being continuously tuned is used for emitting infrared light according to a set period after regulation and control and transmitting the emitted infrared light to the processing unit, the infrared light with the set wavelength is obtained through modulation of the processing unit, and the processing unit transmits the modulated infrared light to the photoacoustic spectrum resonant cavity; the photoacoustic spectrum resonant cavity comprises a buffer cavity and a plurality of resonant cavities which are arranged around the buffer cavity in a central symmetry manner; each resonant cavity is communicated with the buffer cavity to form a plurality of completely consistent T-shaped resonant cavities; according to the method and the device for measuring the SF6 gas decomposition products by the multi-cavity resonance photoacoustic spectrometry, the sensitivity of gas concentration detection can be improved, and the method and the device are suitable for measuring the decomposition products of multi-component gases such as SF6 and the like.

The invention discloses a sound barrier device based on Bragg scattering, cavity resonance and micropore principles, the device is provided with a sound barrier top end structure, and the noise reduction effect is enhanced through the top end structure; the device comprises a screen body, the top end structure of the screen body is provided with a supporting assembly and a sound wave scattering array assembly, the sound wave scattering array assembly is arranged based on the supporting assembly, and the device scatters different frequency components in noise sound waves through the sound wave scattering array assembly on the basis of the Bragg scattering, cavity resonance and micropore principle, so that the sound wave scattering effect is improved. Therefore, the sound energy of noise sound waves is reduced. Noise sound waves can be reduced step by step in combination with Bragg scattering, cavity resonance and micro-perforation theories, so that linear propagation and top diffraction of the noise sound waves can be reduced, and the noise level is reduced.