Double-face sound-absorbing contacting oral cavity sound shield without cotton

A non-wool sound screen with engaged cavities and sound absorptive surfaces is composed of two aluminium fibres sheet layers as surficial layers, two empty cavity layers, two microhole plat layers, a toothed cavity, folded partion, and fixing frame. Its advantage is high effect to decrease noise.

Cleaning chamber

The invention relates to a clean room comprising a wall body surrounding the clean room, a door formed on the wall body, and a pipe. The wall body comprises at least one continuous metallic shielding casing; the door comprises at least one continuous third shielding body; the whole boundary of the third shielding body is in conductive contact with the shielding casing when the door is closed; a cut-off waveguide window which can completely cover the pipeline section of a pipe is arranged in the pipe; and the whole circle of the boundary of the cut-off waveguide window is in conductive contact with the shielding casing. The clean room has the cleaning function and can be used as an electromagnetic shielding chamber. Important components such as the door, a window, an air feeding inlet and the like are installed on the wall body of the clean room, and can be manufactured in a modularization manner, so that not only the difficulty and the cost in construction and installation are reduced, ...

Method for rebuilding circulation calm sound source by boundary element method

The invention relates to a method of reconstructing a circular stable sound source through the boundary element method in the signal reconstruction technical field. Through setting the sound source to be measured, a microphone array and a reference source microphone, the invention synchronously records the acquired reference signal and holographic measuring point sound pressure, obtains a reference phase from the reference signal, obtains the relative phase relation of the holographic measuring point source pressure acquired by the microphone array through the phase relation between the reference signal and the holographic measuring point source pressure, and finally obtains the self-spectrum correlated density vector of the sound source signal to be measured through reconstruction computing via the boundary element method. Through the reconstruction of the sound source signal on the holographic measurement surface acquired by the microphone array, the method can analyze the sound source ...

Process for identifying non-stable ascoustical source characteristic by principal component analyzing technique

Control system for controlling the direction of airflow at clean chamber doorway

The invention relates to a control system for flow direction of the air flow at the doorway of a clean room, which comprises a buffering room abutting with the clean room, a door arranged between the clean room and the buffering room, a microprocessor, a sensor which is arranged on the door and can make a judgment over the open-close state of the door and transmit the judgment to the microprocessor, a first blast pipe communicated with the buffering room, a second blast pipe communicated with the clean room, a first wind volume control valve which is arranged on the first blast pipe and can receive the control signal from the microprocessor, and a second wind volume control valve which is arranged on the second blast pipe and can receive the control signal from the microprocessor.

Method for identifying non-stable acoustic source characteristics by bias coherent technology

采用近场声全息技术辨识非平稳声源的方法

The near field acoustic holographic method of distinguishing non-stationary sound source belongs to the field of noise in physics. In the case of complicated circular smooth sound field with several sound sources, circular smooth theory is used to replace traditional Fourier transformation technology, and spectral correlation density is used as physics for reconstructing sound field, to propose near field holographic technology of circular smooth sound field. Reference microphones are first arranged to extract reference source signal; microphone array is then arranged for the scanning measurement of holographic plane and acquiring the holographic plane data; and finally through reconstruction with near field holographic technology of circular smooth sound field, 3D distribution of the sound field is obtained.

Method for rebuilding circulated steady sound source by boundary element method

The invention relates to a method of reconstructing a circular stable sound source through the boundary element method in the signal reconstruction technical field. Through setting the sound source to be measured, a microphone array and a reference source microphone, the invention synchronously records the acquired reference signal and holographic measuring point sound pressure, obtains a reference phase from the reference signal, obtains the relative phase relation of the holographic measuring point source pressure acquired by the microphone array through the phase relation between the reference signal and the holographic measuring point source pressure, and finally obtains the self-spectrum correlated density vector of the sound source signal to be measured through reconstruction computing via the boundary element method. Through the reconstruction of the sound source signal on the holographic measurement surface acquired by the microphone array, the method can analyze the sound source ...

Method for rebuilding circulation calm sound source by overlapping spherical wave

The invention relates to a method of reconstructing a circular stable sound source to be measured through spherical wave superposition in the signal reconstruction technical field. Through setting the sound source to be measured, a microphone array and a reference source microphone, the invention synchronously records the acquired reference signal and holographic measuring point sound pressure, obtains a reference phase from the reference signal, obtains the relative phase relation of the holographic measuring point source pressure acquired by the microphone array through the phase relation between the reference signal and the holographic measuring point source pressure, and finally obtains the self-spectrum correlated density matrix of the sound source signal to be measured through the spherical wave basis function reconstruction computing. Through the reconstruction of the sound source signal to be measured on the holographic measurement surface acquired by the microphone array, the method ...

Humiture automatic control type purifying combined air conditioning unit for

The invention discloses a humiture automatic control type purifying combined air conditioning unit, which relates to the technical field of the purification engineering of pharmacy, electron, an animal house and the like, in particular to the technical field of purifying air conditioning units for purifying air. The humiture automatic control type purification combined air conditioning unit comprises a hybrid filter section, a surface cooling, heating and humidifying section, an air outlet section of a blower fan and a control section, wherein one side of the control section is provided with the hybrid filter section, the surface cooling, heating and humidifying section and the air outlet section of the blower fan which are interconnected with each other; and the control section is connected with the hybrid filter section, the surface cooling, heating and humidifying section respectively. The purifying humiture automatic control type combined air conditioning unit realizes the aims ofconvenient ...

BLUTSCHONENDER SCHLAUCH MIT VARIABLEM DURCHMESSER FÜR EXTRAKORPORALKREISLAUF

Die vorliegende Erfindung betrifft einen blutschonenden Schlauch mit variablem Durchmesser für einen Extrakorporalkreislauf, mit einem Schlauchkörper, dadurch gekennzeichnet, dass der Schlauchkörper eine Schlauchstruktur mit verschiedenen Durchmessern aufweist, der Durchmesser des Mittelabschnitts des Schlauchkörpers kleiner ist als derjenige eines Endes A und eines Endes B des Schlauchkörpers, der Durchmesser des Endes B des Schlauchkörpers größer ist als derjenige des Endes A, ein glatter Übergangsabschnitt mit variablem Durchmesser zwischen dem Mittelabschnitt des Schlauchkörpers und dem Ende A des Schlauchkörpers und zwischen dem Mittelabschnitt und dem Ende B angeordnet ist, und das Ende A und das Ende B des Schlauchkörpers jeweils Anschlussstellen aufweisen, die einem arteriellen Perfusionsschlauch, einem Venendrainageschlauch, einem Mikroemboliefilteranschluss, einem linksventrikulären Saugschlauch, einem rechtsventrikulären Saugschlauch und einem Anschlussstutzen eines Oxygenators ...

Diagnostic system of non-contact type rotary mechanical failure

The invention relates to a diagnostic system of a non-contact type rotary mechanical failure in the technical field of detection, comprising a sound pressure measurement device, a computer, a sound field reconstructing module, an acoustic holography training sample storage module, an acoustic holography test sample storage module, an off-line training module and an online diagnostic module, wherein the sound pressure measurement device is connected with the computer, the computer is connected with the sound field reconstructing module, the sound field reconstructing module is connected with the acoustic holography training sample storage module and the acoustic holography test sample storage module, the acoustic holography training sample storage module is connected with the off-line training module, the acoustic holography test sample storage module is connected with the online diagnostic module, the off-line training module is connected with the online diagnostic module, the acoustic ...

Method for rebuilding circulation calm sound source by wave overlapping method

The invention relates to a method of reconstructing a circular stable sound source through the wave superposition method in the signal reconstruction technical field. Through setting the sound source to be measured, a microphone array and a reference source microphone, the invention synchronously records the acquired reference signal and holographic measuring point sound pressure, obtains a reference phase from the reference signal, obtains the relative phase relation of the holographic measuring point source pressure acquired by the microphone array through the phase relation between the reference signal and the holographic measuring point source pressure, and finally obtains the self-spectrum correlated density vector of the sound source signal to be measured through the reconstruction computing via the wave superposition method. Through the reconstruction of the sound source signal on the holographic measurement surface acquired by the microphone array, the method can analyze the sound ...

Non-linear rigidity vibration isolator for natural frequency of floating floorboard in high-speed vehicle

The invention relates to a nonlinear rigidity vibration isolator of natural frequency for high speed vehicle floating floor board. It is made from vibration reduction glue and frame board. It has the nonlinear hardening rigidity feature and low system natural frequency and low influence of load to natural frequency. It has good vibration reduction effect and keeps low noise in the vehicle.

Fault detection device based on beam forming acoustic-image mode recognition and detection method thereof

The invention relates to a fault detection device based on a beam forming acoustic-image mode recognition and a detection method thereof, belonging to the industrial detection field. When the noise of a noise source is positioned through acoustic image, a sensitive characteristic is extracted by using the characteristic extraction technology of image processing, so as to represent the acoustic images in normal and failed conditions, and then the characteristic vectors are subjected to training classification by using a support vector machine in mode recognition, and finally fault diagnosis and online monitoring are performed. The invention gives consideration to the characteristics of sound source recognition and frequency domain analysis, develops a fault detection device based on beam forming acoustic-image mode recognition and a method thereof by referring the application of the image diagnosis technology in other fields, perfects the traditional acoustic fault diagnosis technology and ...

Near field acoustic holographic method of distinguishing non-stationary sound source

Fault detecting device of near field acoustic holography sound image mode identification and detecting method thereof

The invention discloses a fault detecting device of near field acoustic holography sound image mode identification and a detecting method thereof in the field of industrial detection. The device comprises a microphone array, a scanner frame, a reference source, a clamped rib plate, an excitation source and a data acquiring system. The invention adopts sound pressure amplitude and distribution changes under mechanical normal and fault states, borrows ideas from applications of an image diagnosis technology in other fields and utilizes image processing, feature extracting and mode identifying technologies to process a near field acoustic holography image. Experiments show that the method is effective, vibration source positioning and identifying functions coordinated with the holographic imaging technology is proven, the image feather extracting and mode identifying technologies are combined with the acoustic imaging technology, thus broadening the application range of the acoustic imaging ...

Method for rebuilding circulation calm sound source by overlapping spherical wave

The invention relates to a method of reconstructing a circular stable sound source to be measured through spherical wave superposition in the signal reconstruction technical field. Through setting the sound source to be measured, a microphone array and a reference source microphone, the invention synchronously records the acquired reference signal and holographic measuring point sound pressure, obtains a reference phase from the reference signal, obtains the relative phase relation of the holographic measuring point source pressure acquired by the microphone array through the phase relation between the reference signal and the holographic measuring point source pressure, and finally obtains the self-spectrum correlated density matrix of the sound source signal to be measured through the spherical wave basis function reconstruction computing. Through the reconstruction of the sound source signal to be measured on the holographic measurement surface acquired by the microphone array, themethod ...

Dual-purpose planing milling machine tool for plate edge and groove

The utility model relates to a planing and milling machine tool for plate edges and grooves. The utility model is composed of a seat body, a material supporting frame part, a pressing loading oil cylinder part, a walking slide table part and a milling and planing part. The utility model can simultaneously implement planing and milling processing to various plates, can overcome the disadvantages of individual work of two machine tools before, can have the advantages of compact equipment and simple and reliable operation, and can be a new generation of the planing and milling machine tool.

Magnetic force switching three-way air valve

The invention relates to a three-way air valve for an air supply system of a clean room, comprising a valve body provided with an air inlet and two air outlets. A valve sheet is rotationally connected with the valve body through a rotating shaft pivot; the two air outlets are respectively positioned at both sides of the valve sheet in a rotation direction; the air inlet is positioned in the middle of the first air outlet and the second air outlet; the valve body is respectively provided with electromagnets on the two air outlets; the valve sheet is provided with a permanent magnet and two working positions; when the valve sheet is positioned on the first working position, the valve sheet plugs the first air outlet, and the second air outlet is opened; when the valve sheet is positioned on the second working position, the valve sheet plugs the second air outlet, and the first air outlet is opened; and when the magnetism of the electromagnet positioned on the first air outlet or the second ...

全透光通风消声窗

All translucent ventilation and sound-deadening window comprising two-layer glass, microperforated panel, sound-deadening air duct, an air renewal draught fan, air admission port, air vent, wherein the two-layer glass is arranged inside and outside the window, two microperforated panels of transparent material are arranged inside the two-layer glass to form microperforated panel cavity sound-deadening arrangement, between the two microperforated panels is a sound-deadening air channel, the sound-deadening window includes an air renewal draught fan and an air admission port on the upper portion, the air vent is arranged beneath the sound-deadening window.

采用偏相干技术辨识非平稳声源特性的方法

The method is as the follows. First, quantity and position of reference source are confirmed, mike array of the reference source is arranged and signal of the reference source is picked up. Then, scan measurement for mike array to holographic face is designed and the holographic face data is collected. At least, sound field of each sound source is separated by utilizing analysis technique of circular sationary partial coherence.

采用主成分分析技术辨识非平稳声源特性的方法

A process for identifying non-stable acoustical source characteristic applying principal component analyzing technique comprising, determining the number and location of the reference source, arranging the reference source microphone array to extract the reference source signal, then designing the microphone array to perform scanning survey to the holographic plane, gathering holographic plane data, then using principal component analysis technique of the circulating stable acoustic field for separating the part acoustic field of the acoustic source, and by rebuilding holographic near-field of the circulation stable acoustic field, a three-dimensional sound field distribution can also be obtained, thus realizing the vision of the acoustic source route of transmission.

Man-machine interactive system of agricultural variable fertilizing machine

The invention discloses a man-machine interactive system of an agricultural variable fertilizing machine, relating to the technical field of automatic control and aiming at solving the problems that an operator of the agricultural variable fertilizing machine can not acquire instantaneous data and can not control fertilizing amount in real time. The system comprises an input module, a user data receiving module, an instantaneous data receiving module, a data conversion module and a display module, wherein the input module is connected with the user data receiving module; the user data receiving module is connected with the data conversion module and a vehicle-mounted computer respectively; the instantaneous data receiving module is connected with the data conversion module and the vehicle-mounted computer respectively; the data conversion module is connected with the user data receiving module, the instantaneous data receiving module and the display module respectively; the display module ...

Fault detecting device of near field acoustic holography sound image mode identification and detecting method thereof

The invention discloses a fault detecting device of near field acoustic holography sound image mode identification and a detecting method thereof in the field of industrial detection. The device comprises a microphone array, a scanner frame, a reference source, a clamped rib plate, an excitation source and a data acquiring system. The invention adopts sound pressure amplitude and distribution changes under mechanical normal and fault states, borrows ideas from applications of an image diagnosis technology in other fields and utilizes image processing, feature extracting and mode identifying technologies to process a near field acoustic holography image. Experiments show that the method is effective, vibration source positioning and identifying functions coordinated with the holographic imaging technology is proven, the image feather extracting and mode identifying technologies are combined with the acoustic imaging technology, thus broadening the application range of the acoustic imaging ...

Cleaning chamber

The invention relates to a clean room comprising a wall body surrounding the clean room, a door formed on the wall body, and a pipe. The wall body comprises at least one continuous metallic shielding casing; the door comprises at least one continuous third shielding body; the whole boundary of the third shielding body is in conductive contact with the shielding casing when the door is closed; a cut-off waveguide window which can completely cover the pipeline section of a pipe is arranged in the pipe; and the whole circle of the boundary of the cut-off waveguide window is in conductive contactwith the shielding casing. The clean room has the cleaning function and can be used as an electromagnetic shielding chamber. Important components such as the door, a window, an air feeding inlet and the like are installed on the wall body of the clean room, and can be manufactured in a modularization manner, so that not only the difficulty and the cost in construction and installation are reduced, but ...

Non-linear rigidity vibration isolator for natural frequency of floating floorboard in high-speed vehicle

辨识声源特性的方法

... 一种辨识声源特性的方法，属于物理专业中噪声类领域。在多个声源同时产生声辐射场合，首先确定主要声源的数量，然后在这些噪声源附近布置与噪声源数量相同的传声器，这些传声器同时测量声压信号，并将这些声压信号通过商用软件或自行编程计算的方法，获得所分析频率范围的互谱矩阵，然后对每个频率的互谱矩阵进行奇异值分解，得到奇异值矩阵和右特征向量矩阵，根据这些位置最大值的位置调整奇异值矩阵中奇异值的位置，将各个频率中调整后的奇异值矩阵的相同位置对角元素的值连接成曲线，即可得到每个噪声源辐射声的频率特性。本发明分析每个声源的频率特性，还可以通过声信号来检测设备的运行状态，诊断故障。 ...

Method for identifying sound source characteristic

In case of existing several sound sources to produce sound radiation simultaneously, the number of main sound source is first determined before arranging microphones, the sound pressure signals are converted into complementary matrix for frequency range analysis, singular value matrix and right characteristic vector matrix are obtained through singular value decomposition, and regulating the position of the singular value in the singluar value matrix and connecting the diagonal element values curve in the singular value matrix can obtain the noise charcteristic of each sound source.