Abstract: A method of free-field broadband calibration of hydrophone sensitivity based on pink noise, relating to the field of free-field underwater acoustic measurement, and is mainly used for broadband measurements of hydrophone sensitivity in free-field. The method of the present disclosure is to transmit a broadband pink noise signal by controlling the signal source, and to perform the synchronous processing and FFT to the transmitted current signal and the received voltage signal, such as interception and zero padding, and finally obtain the transfer function in the frequency domain; by analyzing the direct wave and the reflected wave in the water tank, the transfer function is averaged by a rectangular window to eliminate the influence of the reverberation of the reflected wave in the water tank, so as to obtain the broadband transfer function of the free-field between the transmitting transducer and the hydrophone.

Abstract: A photonic radio-frequency receiver with mirror frequency suppression function, in which a single modulator is utilized to form a photoelectric oscillator so as to generate high-quality and low-phase-noise optically generated local oscillators, without the need for an external local oscillator source, and at the same time, another radio-frequency port is used as a radio-frequency signal input port, thereby allowing a compact structure. By properly setting a bias point for the two-electrode modulator and orthogonally synthesizing two branches of intermediate frequency signals respectively generated by the upper and lower sideband beat frequencies of the modulated optical signal, the photonic radio-frequency receiver realizes the functions of receiving radio-frequency signals and suppressing mirror frequency signals. The present disclosure can realize a photonic mirror-frequency suppression receiver.

Abstract: A frequency chirp correction method for the photonic time-stretch system comprises acquiring the stretching signal, i.e. acquiring the time-domain data after the time-domain stretching. First, the time-domain data of the stretching signal is Fourier transformed to obtain the spectral distribution. The spectral distribution is then convoluted with the first frequency-domain correction factor, and then multiplied with the second frequency-domain correction factor to obtain the modified frequency spectrum. Finally, the modified frequency spectrum is performed by the inverse Fourier transform to obtain the time-domain signal after the frequency chirp correction.

Abstract: A photonic radio-frequency receiver with mirror frequency suppression function, in which a single modulator is utilized to form a photoelectric oscillator so as to generate high-quality and low-phase-noise optically generated local oscillators, without the need for an external local oscillator source, and at the same time, another radio-frequency port is used as a radio-frequency signal input port, thereby allowing a compact structure. By properly setting a bias point for the two-electrode modulator and orthogonally synthesizing two branches of intermediate frequency signals respectively generated by the upper and lower sideband beat frequencies of the modulated optical signal, the photonic radio-frequency receiver realizes the functions of receiving radio-frequency signals and suppressing mirror frequency signals. The present disclosure can realize a photonic mirror-frequency suppression receiver.

Abstract: The present invention provides a method and an apparatus for detecting anti-skimming magnetic interference, wherein the method comprises the steps of: S1: generating an original magnetic strip signal; acquiring an interfered magnetic strip signal by combining the original magnetic strip signal and an interference signal of an electromagnetic interference source to be tested; S2: decoding the interfered magnetic strip signal to obtain a decoded parameter; and S3: determining whether an original magnetic strip parameter is consistent with the decoded parameter; if so, obtaining a first test result that the electromagnetic interference source is unqualified to satisfy a magnetic card reading device's requirement for electromagnetic interference; otherwise, obtaining a second test result that the electromagnetic interference source is qualified to satisfy the magnetic card reading device's requirement for electromagnetic interference whereby security of the magnetic card reading device can be enhanced and the mag

Abstract: An optical sensing device applicable to two dimensional electric field, includes sequentially connected input polarization maintaining fibers, a sensing unit, an output single mode fiber, a photodetector and a signal processing unit, the sensing unit includes a lithium niobate substrate; a first Y optical waveguide and two Mach Zehnder structure optical waveguides are arranged on the lithium niobate substrate; the input of the first Y optical waveguide is connected with the output of the laser source, the output is respectively connected to the inputs of the two Mach Zehnder structure optical waveguides; the outputs of the two Mach Zehnder structure optical waveguides are connected to the photodetector; dipole antenna is arranged at any single waveguide arm of each Mach Zehnder structure optical waveguide, the polarization directions of the two dipole antennas are in orthogonality with each other.

Abstract: Provided are a device and method for identifying a paper currency fold. The device includes: a transparent protective body, configured to maintain components in the device to be clean; a laser source, configured to emit laser light a rectangular grating, configured to modulate the laser light into stripes which changes to be bright or dark according to a certain rule on a surface of a paper currency; an area array photoelectric sensor, configured to capture an image; an imaging lens group, configured to converge an image of the surface of the paper currency onto the area array photoelectric sensor; and an information processing module electrically connected with the area array photoelectric sensor, configured to process an image signal captured by the area array photoelectric sensor.

Abstract: The present invention discloses a phenylate derivative, a preparation method therefor, and a pharmaceutical composition and uses thereof. Specifically, the invention relates to phenylate derivatives represented by formula (I), a pharmaceutically-acceptable salt thereof, a stereoisomer thereof, a preparation method therefor, a pharmaceutical composition containing the one or more compounds, and uses of the compounds in treating diseases related to PD-1/PD-L1 signal channels, such as cancers, infectious diseases and autoimmune diseases.

Abstract: The present invention provides a method and an apparatus for detecting anti-skimming magnetic interference, wherein the method comprises the steps of: S1: generating an original magnetic strip signal; acquiring an interfered magnetic strip signal by combining the original magnetic strip signal and an interference signal of an electromagnetic interference source to be tested; S2: decoding the interfered magnetic strip signal to obtain a decoded parameter; and S3: determining whether an original magnetic strip parameter is consistent with the decoded parameter; if so, obtaining a first test result that the electromagnetic interference source is unqualified to satisfy a magnetic card reading device's requirement for electromagnetic interference; otherwise, obtaining a second test result that the electromagnetic interference source is qualified to satisfy the magnetic card reading device's requirement for electromagnetic interference whereby security of the magnetic card reading device can be enhanced and the mag

Abstract: A note image acquiring system includes: a fiber laser, a fiber beam splitter, a fiber collimator, a laser beam expander, a lithium niobate intensity modulator array, a waveform generator, a signal amplifier, a polarization beam splitter, a quarter-wave plate, an imaging lens group, a line-array photosensitive chip, an image information processing module and an image combining module. The note image acquiring system can improve resolution of details of a note image without needing to increase the number of photosensitive chip units per unit length of a linear array image sensor.

Abstract: A method and device for non-contact detection of a thin medium (5) is disclosed. The device comprises a light source (1), an optical splitter (2), a reference plane (3), a linearly arrayed photoelectric detector (6), a signal processing module (4) and the thin medium (5).

Abstract: An optical sensing device applicable to two dimensional electric field, includes sequentially connected input polarization maintaining fibers, a sensing unit, an output single mode fiber, a photodetector and a signal processing unit, the sensing unit includes a lithium niobate substrate; a first Y optical waveguide and two Mach Zehnder structure optical waveguides are arranged on the lithium niobate substrate; the input of the first Y optical waveguide is connected with the output of the laser source, the output is respectively connected to the inputs of the two Mach Zehnder structure optical waveguides; the outputs of the two Mach Zehnder structure optical waveguides are connected to the photodetector; dipole antenna is arranged at any single waveguide arm of each Mach Zehnder structure optical waveguide, the polarization directions of the two dipole antennas are in orthogonality with each other.

Abstract: A note image acquiring system includes: a fiber laser, a fiber beam splitter, a fiber collimator, a laser beam expander, a lithium niobate intensity modulator array, a waveform generator, a signal amplifier, a polarization beam splitter, a quarter-wave plate, an imaging lens group, a line-array photosensitive chip, an image information processing module and an image combining module. The note image acquiring system can improve resolution of details of a note image without needing to increase the number of photosensitive chip units per unit length of a linear array image sensor.

Abstract: A noise suppressing method, a noise suppressing device and a noise suppressing system are provided. The noise suppressing method includes: receiving internal noise acquired by a reference voice acquisition mechanism and a voice signal containing external noise acquired by a primary voice acquisition mechanism, when the voice signal is inputted; extracting an internal signal feature corresponding to the internal noise, where the internal signal feature is a power spectrum frame sequence; acquiring an external approximate feature corresponding to the external noise based on the internal signal feature and a pre-set mapping formula; converting the external approximate feature into a noise signal estimate by the inverse Fourier transform; and performing a pre-set noise cancellation process on the noise signal estimate and the acquired voice signal containing the internal noise, to obtain a noise-suppressed de-noised voice signal.

Abstract: Provided are a device and method for identifying a paper currency fold. The device includes: a transparent protective body, configured to maintain components in the device to be clean; a laser source, configured to emit laser light a rectangular grating, configured to modulate the laser light into stripes which changes to be bright or dark according to a certain rule on a surface of a paper currency; an area array photoelectric sensor, configured to capture an image; an imaging lens group, configured to converge an image of the surface of the paper currency onto the area array photoelectric sensor; and an information processing module electrically connected with the area array photoelectric sensor, configured to process an image signal captured by the area array photoelectric sensor.

Abstract: A method and device for non-contact detection of a thin medium (5) is disclosed. The device comprises a light source (1), an optical splitter (2), a reference plane (3), a linearly arrayed photoelectric detector (6), a signal processing module (4) and the thin medium (5).

Abstract: A traveling-wave loop antenna based on a metal ring cavity for generating a radio frequency OAM beam includes a main structure which is the metal ring cavity whose top surface has an annular slot circumferentially opened. Two openings, ¼ of a perimeter of the metal ring cavity apart, are two excitation source ports of the antenna, for connecting a metal waveguide. When the two ports are inputted with microwave sources having the same frequency and a phase difference of ±90°, an electromagnetic field in the metal ring cavity exhibits a traveling-wave distribution propagating circumferentially clockwise or counterclockwise. The annular slot constitutes the antenna. A reasonable design of a size of the metal ring cavity and a position of the annular slot realizes a conversion from a microwave guided-wave mode to an OAM mode and a generation of the radio frequency OAM beams with different orders l in free space.

Abstract: A traveling-wave loop antenna based on a metal ring cavity for generating a radio frequency OAM beam includes a main structure which is the metal ring cavity whose top surface has an annular slot circumferentially opened. Two openings ¼ of a perimeter of the metal ring cavity apart, are two excitation source ports of the antenna, for connecting a metal waveguide. When the two ports are inputted with microwave sources having the same frequency and a phase difference of ±90°, an electromagnetic field in the metal ring cavity exhibits a traveling-wave distribution propagating circumferentially clockwise or counterclockwise. The annular slot constitutes the antenna. A reasonable design of a size of the metal ring cavity and a position of the annular slot realizes a conversion from a microwave guided-wave mode to an OAM mode and a generation of the radio frequency OAM beams with different orders l in free space.

Abstract: A preparation method of rosuvastatin calcium (Formula 1), which can be used for the production of medicament lowering the levels of LDL-cholesterol and triglycerides in vivo, is provided. Such preparation method is suitable for industrial production. Furthermore, the intermediate crystallines used in the preparation method are provided.

Abstract: A method for engaging personalized customer services on an end-user device includes sending a request for agent-assisted service to the agent administration server, and receiving from the agent administration server agent information associated with a plurality of customer agents. The agent information defines agent identification information, an agent availability status, and one or more agent communication channels. The method further includes sending a request to communicate with a preferred one agent from the plurality of customer agents. The request includes at least one desired communication channel from the one or more agent communication channels. The desired communication channel is then established with the preferred one agent.