141results about How to "High signal to noise" patented technology

Present invention discloses photons crystal optical fiber probe transducer based on nano particle surface enhancing Raman spectra belonging to laser Raman spectra detection technique. Combining photons crystal optical fiber PCF and SERS spectral technique to obtain PCF-SERS probe transducer having SERS activity, PCF-SERS probe covered with cycle arranged airport, the inner wall of central light guiding air core on PCF-SERS probe end having SERS activity nano metal granule. Said invention can be used in gas and liquid molecule detection with low background noise and high sensitivity, and making exciting light and SERS signal light existing steady mode field in PCF to realize very transmission loss, thereby suitable for on line analysis, real-time analysis, living body analysis, and in situ detecting etc.

The invention provides a merging processing method of 2D seismic data of complex surfaces, belonging to the field of data processing in geophysical exploration. The method is characterized by firstly establishing a spatial model of a 2D seismic data volume, secondly carrying out field one-step static computation on the spatial model of the 2D seismic data volume, thirdly carrying out field one-step static application, pre-stack noise elimination and fidelity and consistency processing on each 2D seismic line in the spatial model and finally improving the signal to noise ratio and resolution of a target layer. The method has the following beneficial effects: by utilizing the method to carry out merging processing on the 2D seismic data acquired in different years, when the profile is processed, the depth error is smaller than the normative index, the structural features are clear, reliable and closed, and the seismic profile which has high resolution, high fidelity and high signal to noise ratio and can more clearly reflect the structure and lithological change characteristics is processed, thus providing reliable processing result for seismic interpretation.

The invention discloses a D2D user resource distribution method based on multicarrier communication, comprising steps of calculating signal to noise ratio on different subcarriers of each D2D user, distributing a subcarrier to each user according to the calculated signal to noise ratio value to enable the signal to noise ratio of each user to be greatest on the distributed subcarrier, performing distribution on the rest of subcarriers according to the signal to noise ratio of a weighing cellular user and the signal to noise ratio of the D2D user until all the subcarriers are distributed to the users, utilizing a subgradient method to perform iteration on lagrange factors and distributing emission power of the D2D user on each subcarrier in order to ensure the cellular user to meet the requirement of the lowest signal to noise ratio and maximization of D2D user system capacity. The D2D user resource distribution method performs subcarrier distribution on the D2D user on the premise that the cellular user lowest signal to noise ratio is guaranteed and establishes an optimized function which targets maximization of system capacity of the D2D user system and uses the cellular user signal to noise ratio and the D2D user emission power as the constraint condition so as to realize the subcarrier distribution and power distribution of the D2D user.

A spectrometer generates Vibrational Circular Dichroism (VCD) measurements having an exceedingly high signal-to-noise ratio, as well as a greater wavelength range over which measurements may be accurately provided. This is achieved by utilizing reflective optics (preferably solely reflective optics, i.e., no refractive elements) to supply a concentrated and collimated input light beam to a sample within a sample cell, and similarly collecting the light output from the sample cell via reflective optics for supply to a detector.

The invention relates to a detection optical fiber based on a surface plasma resonance principle and a sensor. The surface plasma resonance detection optical fiber comprises a fiber core and air holes arranged on the axial direction of the fiber core and is characterized in that the first air hole of a solution channel for detecting is positioned in the center of the cross section of the optical fiber; the inner wall of the first air hole is plated with a metal film; a sensing material is plated on the inner surface of the metal film; N second air holes are distributed in the fiber core and at the periphery of the first air hole uniformly and respectively; N is an integer of more than 1; and the connecting line of the central points of the N air holes is shaped like a regular N-side polygon. According to the detection, mutual influence among the conventional channels of various samples is avoided, the resonance spectrum is narrow, and the signal to noise ratio is high. The sensor breaks through the limit that the refractive index detection upper limit of the conventional similar sensor is less than 1.42 and can effectively detect the chemical organic solution with high refractive index.

The utility model discloses a magneto-stretch sensor used for detection of ultrasound ultrasonic waveform, which belongs to the technical field of acoustic sensors. Bias magnetic circuit which is provided with a plurality of steel stranded wires (1), a jaw (2), a saddle (3), a permanent magnet (4) and a yoke iron (5) makes the magnetic field generated in the steel stranded wires (1) to rotate with the field biased along the direction of the magnetic field. The excitation signal issued by signal generator enter the first enameled wire (7) after being enlarged in a power amplifier. An alternating current magnetic field is produced by the stranded wires in an incentive-in solenoid sensor (6), the coordination of the bias magnetic field and the alternating magnetic field caused by the magnetic domain in the stranded wires are swung back and forth along the axial direction of the magnetic domain, and the change of the magnetic domain is received to the receiving end of the solenoid sensor. The signal is received to the oscilloscopes by a second enameled wire (8), and the waveforms of the signal are displayed by the oscilloscope. The utility model has the advantages that the utility model has low price, ultrasound guided wave can be detected without grinding end face of the stranded wires, and repeatability and operability of detection are improved effectively.

The invention discloses a method for acquiring photoplethysmography signals. The method comprises the following steps: acquiring video of a skin region; carrying out primary treatment on the video of the skin region and outputting primary photoplethysmography signals; and carrying out secondary treatment on the primary photoplethysmography signals, and outputting the photoplethysmography signals, wherein the video of the skin region is a colorful video, and the skin region is a human face region or a finger region. By the method for acquiring photoplethysmography signals, special measuring equipment is not required, measurement is facilitated, and the quality of the acquired photoplethysmography signals is relatively high.

The invention discloses a distributed strain and temperature optical fiber sensor based on brillouin scattering. The sensor comprises a light source, an electro-optical modulator, a pulse signal source, a first erbium-doped optical fiber amplifier, a second erbium-doped optical fiber amplifier, a circulator, a first optical coupler, a second optical coupler, double balance detectors, a signal processing system and a sensing optical fiber. The sensing optical fiber comprises a long period optical fiber grating and is an all-solid photonic crystal band gap optical fiber. Output light of the light source is divided into two paths, wherein one path of the output light is modulated to be detection pulse light by means of the electro-optical modulator, is amplified through the erbium-doped optical fiber amplifiers and is input into the sensing optical fiber through the circulator. The sensor can simultaneously obtain temperature and strain with high resolution through a single measurement, and can well solve the problem of cross sensitivity existing in measurement of a brillouin sensor.

The invention discloses brace porcelain insulator ultrasonic flaw detection method. It includes the following steps: emitting SH wave to detected surface; using transversal wave couplant for the probe and the detected surface; using the probe to check the detected surface; using porcelain insulator test piece to adjust probe reference sensitivity and checking sensitivity; detecting the reflection wave of the detected surface, recording the one which reaches defect setting value as defect signal; measuring the defect length; judging the work piece recorded with defect signal as waste. The invention also discloses the defect detecting probe of which emitted ultrasonic is SH type transverse wave. The method has high sensitivity, reliability, and large detecting range. Meanwhile the special probe has little size which can ensure detecting sensitivity and increase porcelain vase retrievable rate at the same time.

The invention relates to a prism-coupled SPR biosensor, which comprises an optical plastic prism, an inner metal film layer, an outer metal film layer and a biological component layer; The outer metal film layer is deposited on the film layer, the inner metal film layer and the outer metal film layer can be two kinds of the same or different metal film layers, and the sum of the thickness of the inner metal film layer and the outer metal film layer is between 20-80nm The space meets the optical requirements for exciting surface plasmon resonance, and a biological component layer is fixed on the surface of the outer metal film layer. The present invention also relates to the use of the prism-coupled SPR biosensor in preparing biochips and its use in detecting interactions between biological samples.

The invention discloses a silicon substrate integrated coherent light transmitter chip and a transmitter. The silicon substrate integrated coherent light transmitter chip comprises an optical coupler, a light beam splitter, a light beam combining device, a silicon substrate modulator, a fixed phase drift device and a coupling polarization beam combining device. The optical coupler is used for achieving coupling of input end light. The light beam splitter and the light beam combining device are used for achieving the beam splitting and beam combining functions of optical signals. The silicon substrate modulator is a core modulator part, and is used for achieving the function of loading electrical signals to the optical signals, and generation of modulation signal light is finished. The fixed phase drift device is used for achieving fixed rotating of the phase position of the optical signals. The coupling polarization beam combining device is used for combining two paths of signal light with the transverse electric (TE) polarization state into one path of transverse electric and magnetic field (TEM) signal light. The silicon substrate integrated coherent light transmitter chip and the transmitter are suitable for an optical communication system with multi-phase-position modulating and polarization multiplexing, and have the advantages that cost is low, the CMOS technology is compatible, achieving is easy, integrity is high, and packaging is easy.

The invention provides a multifunctional near infrared fluorescent probe. The chemical formula of the multifunctional near infrared fluorescent probe is as shown in formula (I), wherein X<1> is -S- or -Se-, R' is C1-12 alkylene, X<2> is -C(CH3)2-, -O- or -Se-, each of R1 and R2 is independently selected from H atoms, C1-18 alkyl or groups as shown in SO3R9, R9 is C1-18 alkyl or benzyl, each R3 and R4 is independently selected from C1-18 alkyl or benzyl, each of R5, R6, R7 and R8 is independently selected from C1-18 alkyl or C1-18 alkyl containing at least one of F, Cl, Br, I, O and S, and each of Y1 and Y2 is independently selected from F, Cl, Br or I. The multifunctional near infrared fluorescent probe can simultaneously detect pH and mercaptan, is a double-response ratio type near infrared fluorescent probe and can be used for the photodynamic therapy of tumors. The invention further provides a preparation method and application of the probe.

The invention discloses a magnetic multilayer film as well as a magnetic logic element and a magnetic random access memory thereof. The magnetic multilayer film disclosed by the invention comprises a first antiferromagnetic layer, a first hard magnetic layer, a first non-magnetic metal layer, a second soft magnetic layer, a tunnel barrier layer, a third soft magnetic layer, a second non-magnetic metal layer, a fourth hard magnetic layer and a second antiferromagnetic layer from bottom to top, wherein the third magnetic layer is set to be have a first critical current capable of turning over the magnetization direction of the third magnetic layer and the second magnetic layer is set to be have a second critical current capable of turning over the magnetization direction of the second magnetic layer, and the first critical current is not equal to the second critical current. The magnetic logic element and the magnetic random access memory based on the magnetic multilayer film disclosed by the invention have the advantages of higher read-write speed, relatively small current density required by read-write operation and low consumed power, and energy saving.

The invention discloses a coding beam-splitting phase measurement device and method, and the device just needs one light spot detector, one weak scattering sample in the known distribution, two-dimensional gratings with the equal diffraction-order light intensity distribution, and a corresponding fixing device. The cost of the device is far less than the cost of a conventional interferometer, and the device exerts low requirements for the stability of an environment. A to-be-measured light beam is split by the gratings, and then forms a plurality of separated diffraction spots on an imaging target surface through the weak scattering sample in the known distribution. An iteration algorithm is used for processing each diffraction spot, and the wavefront amplitude and phase of the to-be-measured light beam are restored. According to the invention, the plurality of different diffraction spots are obtained through the splitting effect of the gratings. Compared with a method employing one diffraction spot for iteration restoration, the method is higher in resolution in an iteration restoration process. Because only one diffraction spot needs to be recorded, the measurement process is simple and quick. The device and method can be used for the wavefront detection of pulse laser, and provide a solution for the wavefront measurement.

The invention discloses a rubbing acoustic emission denoise method based on empirical wavelet transform. The method comprises the following steps that (1) an acoustic emission signal is acquired through a rubbing acoustic emission experimental device; (2) adaptive partition is performed on the acoustic emission signal according to the Fourier spectrum features; (3) a wavelet window is added after partition, and an empirical scale function and an empirical wavelet function are defined; (4) empirical wavelet transform is defined; and (5) wavelet denoising is performed on each empirical mode component fi and then reconstruction is performed based on EWT. The beneficial effects of the rubbing acoustic emission denoise method based on empirical wavelet transform are that adaptive partition is performed according to the Fourier spectrum of the acoustic emission signal, and a wavelet filter bank is constructed to extract different intrinsic mode components included in the acoustic emission signal so that less modes are decomposed and the phenomena of mode aliasing and endpoint effect can be effectively filtered; and wavelet denoising is performed on each empirical mode component, reconstruction is performed based on EWT and denoising is performed on the signal so that the denoised signal has high signal-to-noise ratio and the denoise effect is obvious.

The invention discloses a transmission method for multimedia broadcast and multicast service (MBMS), which includes the following steps: according to the principle that a channel has the strongest independence, spatial channels for transmitting the MBMS service in various periods of time are determined; on a spatial channel corresponding to each period of time, the MBMS service data is sent to a receiving terminal. The invention also discloses a network device which is used for transmitting the MBMS service. By adopting the technical proposal of the invention, the transmission property of the MBMS service can be effectively improved, and the coverage area of MBMS districts can be further enlarged.

The invention belongs to the field of magnetic resonance imaging, discloses an improved reconstruction method for parallel magnetic resonance images and particularly relates to a reconstruction method suitable for K spatial data in the parallel magnetic resonance imaging process. According to the method, when a weight coefficient is fitted, estimation is carried out with a K spatial data area and a self-calibration data area near undersampled data instead of adjacent points and a self-calibration line, and thus the nonlinear relation of K spatial data can be better fitted; noise in the sampled signals can be suppressed in the singular value decomposition and truncation processing process, and it is ensured that the signal-to-noise ratio of images is high. The method is a GRAPPA improving method based on matrix generalized inverse and singular value decomposition, the noise of the K spatial data can be suppressed, the fitting precision can be improved, and meanwhile the imaging quality can still be ensured when an acceleration factor is large.

The invention relates to a system for identifying ID (identity) information of a lamp by white light of an LED (light-emitting diode). The system comprises a transmitting part and a receiving part, wherein the transmitting part comprises an information unit module which is used for transmitting the ID information of the lamp to an information encoding and modulation circuit module; an LED driving power supply module is used for transmitting constant current to a current control circuit module; the information encoding and modulation circuit is used for performing numbering and modulation on the information transmitted by the information unit module, then outputting a control signal and transmitting to the current control circuit module for further control of the output current of the current control circuit module; the LED power supply is used for receiving a current signal output by the current control circuit module and converting the current signal to an optical signal; and a photoelectric detection circuit module is used for receiving the optical signal of the LED lamp and converting the optical signal to an electric signal, and the electric signal is output after signal analysis processing and decoding by a decoding circuit module. The structure can be applied in a dark environment or an environment with single background light, and can be used for monitoring the state of a light source or positioning a mobile lamp and the like.

The invention discloses a playback circuit of a micro-array biologic sensor, which includes a buffered output unit, and a current integration unit which is connected with the output terminal of the micro-array biologic sensor and provides a constant bias voltage between the working electrode and the counter electrode of the micro-array biologic sensor, and transforms the current signal from the micro-array biologic sensor into the voltage signal; and a correlated double sampling unit which is connected between the potentiostat current integration unit and the buffered output unit, the voltage signal outputted from the correlated double sampling unit sampling potentiostat current integration unit is denoised and outputted to the buffered output unit. The invention can eliminate the noise signal in the biological microelectrode sensor output signal, and improves the signal-noise ratio of the biological microelectrode sensor output signal.

The invention discloses a line light source excitation-based rapid high-throughput hyperspectral detection device and a detection method. The detection device comprises a light source, an objective lens or lens, a displacement stage, a filter plate, a focusing lens and an imaging spectrometer. A sample to be measured is placed on the displacement stage; light emitted from the light source successively passes through the objective lens or lens, the displacement stage and the sample to be measured; and light that the sample to be measured radiates passes through the filter plate and the focusing lens and then enters the imaging spectrometer. By illuminating the sample through the light source, scanning the sample through the displacement stage and acquiring spectral signals that the sample radiates through the imaging spectrometer, spectrum and spatial position information of the sample can be obtained rapidly. By the active lighting mode, signal to noise ratio of the system is high, and quantitative detection of an object can be realized.

The invention discloses a detection method, a device and an electronic device for coffee ripe fruit, wherein, the method comprises the following steps of: obtaining an image to be detected; A superpixel segmentation is carried out on that image to be detected, and a plurality of superpixel subimage are obtained; A superpixel sub-image is detected based on a coffee fruit ripening detection model todetermine that coffee ripen fruit in the superpixel sub-image; Among them, coffee fruit ripening detection model is obtained by training the supervised learning algorithm with sample images. By usingthe superpixel as the minimum unit to detect coffee ripe fruit, the superpixel segmentation can keep the shape of fruit and the signal-to-noise ratio is high, which provides a basis for the detectionof coffee ripe fruit by using the detection model of coffee ripe period. In addition, because the coffee fruit ripening detection model is obtained by training the supervised learning algorithm withsample images, it can ensure that the detection model after training has high detection accuracy, and then can achieve high accuracy of coffee ripening detection.

The invention discloses a method for performing intelligent division for the stratigraphic position based on logging information. The method comprises the following steps that a, the curve peak and valley are found; b, the relative depth difference and the measured coordinate difference between two wells are calculated; c, the input curve is smoothed; d, single curve similarity detection is performed; e, multi-curve similarity detection is performed; f, a stratigraphic division model based on the single curve is established; and g, a stratigraphic division model based on the multiple curves isestablished. According to the method, the idea of performing stratigraphic division by using the mathematical algorithm according to the logging information is put forward for the first time so thattwo problems of high artificial influence factor of stratigraphic division and difficulty of transmission of the division experience can be overcome, and the speed and the accuracy of stratigraphic division can be enhanced.

The invention provides a detection apparatus of carrier envelope phase signals. The detection apparatus is characterized by comprising a pulse oscillator, a fiber amplifier, a spectrum spread device and a collinear type self-reference f-2f carrier envelope phase detection module which are successively connected through an optical path, wherein the collinear type self-reference f-2f carrier envelope phase detection module comprises multiple lenses, a PPLN crystal, a YV04 crystal and a photoelectric detector which are connected through an optical path, the lens is used for converting fiber light output by the spectrum spread device into space light, the YV04 crystal is used for introducing time-delay amounts of fundamental frequency light and frequency multiplication light, and the YV04 crystal is internally of an oblique cleft structure whose left portion and right portion can be vertically adjusted. Femtosecond pulses are injected into high-nonlinearity fibers for generating needed long-wave signals and short-wave signals, phase delays of long-wave signal pulses and short-wave signal pulses are optimized through polarization dispersion and envelope velocity dispersion of the YV04 crystal, and compared to a method of modifying a time-delay amount by use of space light path adjustment in a conventional apparatus, the accuracy is greatly improved.

The invention relates to a polarized light scattering measurement system and method based on magneto-optic modulation. Coherent light sent out by a laser is changed to linear polarized light through a polarizer, and the linear polarized light is focused into a sample matching tank through a focusing lens. Scattered light coming out from the sample matching tank passes through an expanded beam collimating lens to reduce a divergence angle of the scattered light and collimate the diameter of an outgoing beam, and then the scattered light passes through a Faraday coil, a polarization analyzer and an expanded beam lens in sequence to obtain linear polarized light with periodic changes which can be received by a photomultiplier tube after passing through an aperture diaphragm capable of limiting a photosensitive area, signals are sent into a phase-locked amplifier by the photomultiplier tube to filter and remove external noise and white noise inside equipment, and then sent into a sampling integrator and a computer for sampling integration and digital average to obtain the particle size distribution. Compared with the prior art, the polarized light scattering measurement system and method based on the magneto-optic modulation can be used for low-intensity laser measurement without interference or damage to a sample, can be used for quickly and accurately measuring the nanoparticle size, suppressing the noise to the maximum extent and improving the measurement accuracy to enable the system to be suitable to be used in various environments.

The invention, which belongs to the technical field of mineral identification, proposes a mineral identification method based on reflection spectrum. The method comprises the following steps: S1, carrying out data measurement; to be specific, measuring a plurality of sampling points in a sample by using a spectrograph to obtain a measurement value; S2, carrying out data processing; to be specific,acquiring a spectral waveform of each sampling point based on the measurement value of each sampling point in the S1, carrying out splicing correction, and then carrying out equalization to obtain aspectral waveform of the sample; S3, carrying out mineral identification; to be specific, carrying out calculation on the spectral waveform data of the sample in the S2 to obtain the position of a characteristic valley, carrying out standard matching on typical minerals in a spectrum database based on the wavelength of the characteristic valley to obtain a matched mineral, and then comparing the spectral waveform of the matched mineral with the spectral waveform of the sample to obtain minerals that may exist in the sample; and S4, carrying out data calculation; to be specific, carrying out fitting calculation on the minerals that may exist in the sample to obtain mineral compositions in the sample and relative content of all compositions. Therefore, problems of low recognition precision and long recognition time in the prior art are solved.

The invention provides a three-dimensional seismic data multi-block merging processing time difference correction method and apparatus. The method includes following steps: determining a main block as the initial block from to-be-merged data blocks, and determining the main block as zero time difference; determining the merging direction and route; determining a to-be-corrected block according to the merging direction and route; obtaining the time difference enabling cross correlation of seismic signals between the initial block and the to-be-corrected block to be maximum, and taking the time difference as the time difference between the initial block and the to-be-corrected block; performing time shift on the seismic signals of the to-be-corrected block according to the obtained time difference to realize time difference correction between the to-be-corrected block and the initial block; and determining a new initial block and a new to-be-corrected block according to the determined merging direction and route when the to-be-corrected block is not the last to-be-merged data block, and executing the steps of time difference obtaining and time difference correction repeatedly.

The invention discloses a head radiofrequency coil for a magnetic resonance imaging system. The radiofrequency coil comprises a coil shell (1), a vacuum shield (2), a liquid nitrogen apparatus and a coil conductor (3). The radiofrequency coil is a radiofrequency receiving coil or an operable radiofrequency coil capable of both transmitting and receiving. The coil conductor (3) consists of end rings (4), legs (5) in even number and resonant capacitors (6), wherein the legs (5) parallel one another are connected to two ends of the end rings (4), and the resonant capacitors (6) are connected with the coil conductor (3). The coil conductor (3) of different structure can be selected according to different direction of a main magnetic field. The liquid nitrogen apparatus is arranged on the coil conductor (3) and refrigerates a coil through liquid nitrogen. The coil conductor can be used as the receiving coil or the receiving / transmitting coil, has good orthogonal receiving and excitation performance and has high uniformity in imaging areas. Since the conductor is cooled by the liquid nitrogen, loss caused in the magnetic resonance receiving process and thermal noise generated due to resistance can be reduced and the signal-to-noise ratio of acquired images is increased.

The invention relates to a unidirectional stress electromagnetic ultrasonic detection method, belongs to the technical field of detection and particularly relates to a unidirectional stress electromagnetic ultrasonic detection system and a detection method. The method comprises the following steps: assembling the electromagnetic ultrasonic detection system, acquiring signal waveforms of an electromagnetic ultrasonic transverse wave probe and an electromagnetic ultrasonic longitudinal wave probe on unidirectional stress detection, and calculating the size of the unidirectional stress through atransverse and longitudinal wave combined detection theoretical formula. In the detection method, the electromagnetic ultrasonic transverse wave probe and the longitudinal wave probe are used for exciting the ultrasonic transverse wave and the ultrasonic longitudinal wave to perform combined detection on the unidirectional stress, the external electromagnetic interference can be shielded, and thesignal-to-noise ratio is high. The defect that the influence on the stress detection by bolt deformation is not considered by the traditional single waveform is overcome, combined detection on the unidirectional stress by the electromagnetic ultrasonic transverse and longitudinal probes is realized, the influence on detection by axial tensile deformation can be eliminated, and the detection precision is high.

The invention provides a near infrared fluorescence probe with extremely acid pH response. The chemical structural formula is shown by a formula (I), wherein X is -C(CH3)2-, -O-, -S- or -Se-; Z is -CH2-Ph or a group shown by -R'NH2; R' is C1-12 alkylene; R1 and R2 are separately selected from H atom, C1-18 alkyl or a group shown by -SO3R5; R5 is C1-18 alkyl or benzyl; R3 and R4 are separately selected from C1-18 alkyl or benzyl; and Y is F, Cl, Br or I. The near infrared fluorescence probe has the advantages of relatively low pKa value, relatively high sensitivity to H<+>, high selectivity, relatively large stocks displacement, little background interference and relatively low harm to cells and living body and is very suitable for detecting pH in an extremely acid environment and overcomes the defects of the fluorescence probes of the prior art. The invention also provides a preparation method and an application of the probe.

The invention discloses a voice recognition method, device and system. Through at least one microphone held by each user, a multichannel signal receiver can receive to-be-recognized voice sent by allmicrophones through different channels, and thus, a voice recognition terminal can carry out voice recognition on the to-be-recognized voice received by each channel of the multichannel signal receiver, wherein one channel of the multichannel signal receiver receives the to-be-recognized voice sent by one microphone. Thus, through the technical scheme provided by the embodiment of the invention, the voice recognition terminal can carry out voice recognition on voice acquired by each microphone respectively; as the user can hold at least one microphone, the voice acquired by each microphone hasa high signal-to-noise ratio, and thus, even if in a complex environment, the voice recognition terminal can carry out quick and accurate voice recognition.