Abstract: A shear vibration-based piezoelectric composite material and a preparation method thereof are disclosed. The piezoelectric composite material includes a piezoelectric material and the passive material. The piezoelectric material includes a piezoelectric material polarized along the x-axis positive and a piezoelectric material negatively polarized along the x-axis. The piezoelectric materials in the two polarization directions are alternately arranged along the x-axis direction. The passive material includes a filling layer, a transition layer, and a planar layer. The filling layer is disposed between every two adjacent piezoelectric materials. The planar layer is located outer two surfaces perpendicular to the z-axis of the piezoelectric material. The planar layer on one side is fixedly connected to the filling layer in the odd-numbered position via the transition layer. The planar layer on the other side is fixedly connected to the filling layer in the even-numbered position via the transition layer.

Abstract: The present invention relates to a method for establishing a digitalized interpretation base of Dongba classic ancient books, comprising the following steps: collecting existing Dongba classic ancient book information and establishing a Dongba classic ancient book interpretation information base, wherein the interpretation information base comprises a picture template base, an audio template base and a video template base; establishing a Dongba classic ancient book interpretation database according to the Dongba classic ancient book interpretation information base, wherein the interpretation database comprises a word meaning database, a sentence meaning database and an event database; establishing a Dongba classic ancient book interpretation knowledge base to perform management for the interpretation database: the interpretation knowledge base combining interpretation contents of the three types of interpretation databases according to interpretation rules, and utilizing an inference engine to promote fusion

Abstract: The present invention relates to a method for establishing a digitalized interpretation base of Dongba classic ancient books, comprising the following steps: collecting existing Dongba classic ancient book information and establishing a Dongba classic ancient book interpretation information base, wherein the interpretation information base comprises a picture template base, an audio template base and a video template base; establishing a Dongba classic ancient book interpretation database according to the Dongba classic ancient book interpretation information base, wherein the interpretation database comprises a word meaning database, a sentence meaning database and an event database; establishing a Dongba classic ancient book interpretation knowledge base to perform management for the interpretation database: the interpretation knowledge base combining interpretation contents of the three types of interpretation databases according to interpretation rules, and utilizing an inference engine to promote fusion

Abstract: A fiber grating demodulation system for enhancing spectral resolution by finely adjusting a slit, includes a laser pump source, a wavelength division multiplexer, a fiber Bragg grating, a diaphragm, a slit, a collimating mirror, a light splitting grating, an imaging focus mirror, and a linear array detector. The laser pump source, the wavelength division multiplexer, the fiber Bragg grating are connected in sequence, and the wavelength division multiplexer is connected to the diaphragm. Light emitted from the laser pump source is multiplexed by the wavelength division multiplexer and then enters the fiber Bragg grating, a reflection spectrum of the fiber Bragg grating enters the slit of the fiber grating demodulation system as injected light. After passing through the slit, the injected light is reflected by the collimating mirror, the light splitting grating, and the imaging focus mirror in sequence, and is finally converged to the linear array detector.

Abstract: The present invention provides a method for implementing high-precision orientation and evaluating orientation precision of a large-scale dynamic photogrammetry system, including steps: a) selecting a scale bar, arranging code points at two ends of the scale bar, and performing length measurement on the scale bar; b) evenly dividing a measurement space into multiple regions, sequentially placing the scale bar in each region, and photographing the scale bar by using left and right cameras; d) limiting self-calibration bundle adjustment by using multiple length constraints, adjustment parameters including principal point, principal distance, radial distortion, eccentric distortion, in-plane distortion, exterior orientation parameter and spatial point coordinate; and e) performing traceable evaluation of orientation precision of the photogrammetry system. The present invention can effectively reduce the relative error in length measurement.

Abstract: A fiber grating demodulation system for enhancing spectral resolution by finely adjusting a light splitting grating, includes a laser pump source, a wavelength division multiplexer, a fiber Bragg grating, a diaphragm, a slit, a collimating mirror, a light splitting grating, an imaging focus mirror, and a linear array detector. The laser pump source, the wavelength division multiplexer, the fiber Bragg grating are connected in sequence, the wavelength division multiplexer is connected to the diaphragm. Light emitted from the laser pump source is multiplexed by the wavelength division multiplexer and then enters the fiber Bragg grating, a reflection spectrum of the fiber Bragg grating enters the slit of the fiber grating demodulation system as injected light. After passing through the slit, the injected light is reflected by the collimating mirror, the light splitting grating, and the imaging focus mirror in sequence, and is finally converged to the linear array detector.

Abstract: A fiber grating demodulation system for enhancing spectral resolution of a detector array, includes a laser pump source, a wavelength division multiplexer, a fiber Bragg grating, a diaphragm, a slit, a collimating mirror, a light splitting grating, an imaging focus mirror, and a linear array detector. The laser pump source, the wavelength division multiplexer, and the fiber Bragg grating are connected in sequence, and the wavelength division multiplexer is connected to the diaphragm. Light emitted from the laser pump source is multiplexed by the wavelength division multiplexer and then enters the fiber Bragg grating. A reflection spectrum of the fiber Bragg grating enters the slit of the fiber grating demodulation system as injected light. After passing through the slit, the injected light is reflected by the collimating mirror. The light splitting grating, and the imaging focus mirror in sequence, and is finally converged to the linear array detector.

Abstract: A fiber grating demodulation system for enhancing spectral resolution by finely adjusting an imaging focus mirror, includes a laser pump source, a wavelength division multiplexer, a fiber Bragg grating, a diaphragm, a slit, a collimating mirror, a light splitting grating, an imaging focus mirror, a linear array detector. The laser pump source, the wavelength division multiplexer, the fiber Bragg grating are connected in sequence, the wavelength division multiplexer is connected to the diaphragm. Light emitted from the laser pump source is multiplexed by the wavelength division multiplexer and then enters the fiber Bragg grating, a reflection spectrum of the fiber Bragg grating enters the slit of the fiber grating demodulation system as injected light. After passing through the slit, the injected light is reflected by the collimating mirror, the light splitting grating, and the imaging focus mirror in sequence, and is finally converged to the linear array detector.

Abstract: A fiber grating demodulation system for enhancing spectral resolution by finely adjusting a collimating mirror, includes a laser pump source, a wavelength division multiplexer, a fiber Bragg grating, a diaphragm, a slit, a collimating mirror, a light splitting grating, an imaging focus mirror, a linear array detector. The laser pump source, the wavelength division multiplexer, and the fiber Bragg grating are connected in sequence, the wavelength division multiplexer is connected to the diaphragm Light emitted from the laser pump source is multiplexed by the wavelength division multiplexer and then enters the fiber Bragg grating, a reflection spectrum of the fiber Bragg grating enters the slit of the fiber grating demodulation system as injected light. After passing through the slit, the injected light is reflected by the collimating mirror, the light splitting grating, and the imaging focus mirror in sequence, and is finally converged to the linear array detector.

Abstract: The present invention provides an angular rate gyro in which a bell-shaped vibrator having nonuniform thickness, axially symmetric and multi curved surface combined structural features is used as a sensitive element. The angular rate gyro is composed of the bell-shaped vibrator, a vibrator fixing shaft, a vibrator base, an airtight hood, a housing and a circuit system. The bell-shaped vibrator includes a bell shoulder having a hemispheric shell structure, a bell waist having a cylindrical shell structure and a bell lip having a hyperboloidal shell structure. The bell-shaped vibrator, the base and a central shaft are mechanically and fixedly connected together to be formed into an integral core having sensitive gyratory effect. A circuit system is used to control vibration forms of the bell-shaped vibrator, perform signal processing and solve the applied angular rate.

Abstract: A gas detection system with an inner ring cavity fiber laser using saturated absorption optical fiber is provided. The system comprising a ring fiber laser consisted of a pump source, a wavelength division multiplexer, a first active optical fiber, a first coupler, a fiber Bragg grating and a second coupler connected successively; an optical isolator coupled between said first active optical fiber and said first coupler; a second active grating connected between said fiber Bragg grating and said first coupler; a detection gas chamber connected between said first coupler and said second coupler; a first photoelectric detector for detecting the laser intensity outputted from said ring fiber laser to generate a first light intensity signal; a second photoelectric detector for receiving the intensity measuring beam passing through the detection gas chamber to generate a second light intensity signal; and a feedback control unit.

Abstract: A method for measuring the strain of material using a short cavity fiber laser, includes steps of: a) arranging the short cavity fiber laser, which laser comprises sequentially coupled laser diode pumping source, a wavelength division multiplexer, a fiber bragg grating, an active fiber and a loop mirror; b) fixing the short cavity fiber laser on the material whose strain will be measured, and matching the stretching direction of the fiber of the short cavity fiber laser with the direction of the strain produced by the material to be measured; c) measuring the drift amount of longitudinal mode output by the short cavity fiber laser; and d) calculating and obtaining the strain of the material to be measured.

Abstract: The present invention provides a fiber laser gas detection system using active feedback compensation by a reference cavity, said system comprising: an optical fiber laser consists of a laser diode pump source, a wavelength division multiplexer, an active optical fiber and a fiber Bragg grating connected successively; an optical isolator coupled with said wavelength division multiplexer for blocking a reverse light transmission in said active fiber; a coupler connected with said optical isolator for dividing the laser light after being isolated by the optical isolator into a reference beam, a detecting beam and an intensity measuring beam according a certain ration power. The gas detection system according to the present invention can take advantages of the unique superiority of compact structure and narrow linewidth of the laser output of the fiber laser, and achieve a gas detection method with high sensitive and high precision by feedback controlling.

Abstract: A fiber laser gas detection system with a double wavelength combination using reference cavity compensation is provided. The system comprises an optical fiber laser respectively emitting beams having a first and second wavelengths, which consists of a laser diode pump source, a first wavelength division multiplexer, an active optical fiber, a first fiber bragg grating and a second fiber bragg grating connected successively; an optical isolator; a coupler for dividing the beams according to power ratio, the divided beams is introduced into a reference gas chamber and a detecting gas chamber respectively; a second wavelength division multiplexer connecting the reference room and a third wavelength division multiplexer connecting the detecting gas chamber; a first, a second, a third and a fourth photoelectric detector; a feedback control unit, receiving the first to fourth light intensity signals and adjusting the fiber laser using the comparison results as a feedback signal.

Abstract: A method for measuring the strain of material using a short cavity fiber laser, includes steps of: a) arranging the short cavity fiber laser, which laser comprises sequentially coupled laser diode pumping source, a wavelength division multiplexer, a fiber bragg grating, an active fiber and a loop mirror; b) fixing the short cavity fiber laser on the material whose strain will be measured, and matching the stretching direction of the fiber of the short cavity fiber laser with the direction of the strain produced by the material to be measured; c) measuring the drift amount of longitudinal mode output by the short cavity fiber laser; and d) calculating and obtaining the strain of the material to be measured.

Abstract: A gas detection system using a semiconductor laser with a reference gas cavity compensation is provided, said system comprising a first light source emitting a first beam of a first wavelength as a detection beam; a second light source emitting a second beam of a second wavelength, which is different from the first wavelength, as a reference beam; a first wavelength division multiplexer connected with said first light source and said second light source; a broadband coupler connected with said first wavelength division multiplexer; a reference gas chamber, which is introduced with reference gas of the same composition as that of the gas to be detected and of a known concentration; a detection gas chamber, which is introduced with the gas to be detected.

Abstract: The present invention provides an angular rate gyro in which a bell-shaped vibrator having nonuniform thickness, axially symmetric and multi curved surface combined structural features is used as a sensitive element. The angular rate gyro is composed of the bell-shaped vibrator, a vibrator fixing shaft, a vibrator base, an airtight hood, a housing and a circuit system. The bell-shaped vibrator includes a bell shoulder having a hemispheric shell structure, a bell waist having a cylindrical shell structure and a bell lip having a hyperboloidal shell structure. The bell-shaped vibrator, the base and a central shaft are mechanically and fixedly connected together to be formed into an integral core having sensitive gyratory effect. A circuit system is used to control vibration forms of the bell-shaped vibrator, perform signal processing and solve the applied angular rate.

Abstract: A method for measuring magnetic induction intensity of a magnetic field using a short cavity fiber laser, includes the steps of: a) arranging the short cavity fiber laser, where the short cavity laser has sequentially coupled laser diode pumping source, a wavelength division multiplexer, a fiber Bragg grating, an active optical fiber and a loop mirror; b) fixing the short cavity fiber laser on a magnetostrictive material; c) disposing the short cavity fiber laser and the magnetostrictive material in the magnetic field to be measured, and matching the stretching direction of the magnetostrictive material with the direction of the magnetic field to be measured; d) measuring the drift amount of longitudinal mode output by the short cavity fiber laser; and e) calculating the magnetic induction intensity of the magnetic field to be measured.

Abstract: A method for measuring temperature of an object using the longitudinal mode output by a short cavity fiber laser, includes steps of: a) arranging the short cavity fiber laser, which laser comprises sequentially coupled laser diode pumping source, a wavelength division multiplexer, a fiber bragg grating, an active optical fiber and a loop mirror which are; b) contacting the short cavity fiber laser with the object whose temperature will be measured; c) measuring the drift amount of longitudinal mode output by the short cavity fiber laser; and d) calculating the temperature of the object to be measured. According to the present invention, the temperature can be measured accurately utilizing the features of the short cavity fiber laser. The arranged fiber laser has a small and simple structure, high measuring accuracy, good portability, and can be used in a variety of occasions.