Abstract: A sequence time window amplitude-phase-frequency characteristics analysis method and system for underwater vehicle power frequency electromagnetic field disturbance are provided. The method includes: establishing a power grid dipole group model, emulating and calculating to obtain background field intensity data of a test location, and constructing an emulated background field database; acquiring measured background field data, comparing the emulated data with the measured data, and providing a relative error; calculating a background field intensity and underwater vehicle target disturbance under the action of the above dipole group, and establishing a measured target signal database; and performing actual measurement according to an underwater vehicle motion and detection topology, performing a Fourier transform and Fourier sliding window decomposition after acquiring original data, and acquiring an amplitude spectrum and a spectrogram of an underwater vehicle target disturbance signal.

Abstract: The present invention discloses an electromagnetic wave spatial analysis method based on multi-level dipole group modeling.

Abstract: A power supply circuit and a field emission electron source are provided. The power supply circuit includes: field effect transistors Si coupled in series via drains and sources in sequence, 1?i?n, i and n are natural numbers, n?2, and a source of S1 is coupled to a negative electrode of a voltage source, and a drain of Sn is used as an output terminal of the power supply circuit to couple to a load; a first group of diodes D1i coupled in series; a first group of resistors R1j, 2?j?n, and i and j are natural numbers; and a voltage control module configured to adjust an output voltage of the voltage source to cause a current passing through the load to be constant; the field effect transistors Si, 1?i?n, operate in a resistive region.

Abstract: A time-division multiplexing control device applied to a distributed X-ray source includes: a first switch module with a number of first switches that receive a high-voltage signal and a first control signal, selectively turning on one of the plurality of first switches according to the first control signal and sending the high-voltage signal through the first switch turned on; and a cathode control module including a plurality of cathode control stages in one-to-one correspondence with the plurality of first switches, used for receiving the high-voltage signal from the first switch module and sending working state data through a cathode control stage corresponding to the first switch turned on in the plurality of cathode control stages, where each cathode control stage includes a cathode control unit and a cathode.

Abstract: Disclosed are an underwater ferromagnetic target detection method and system employing multiple power frequency radiation sources, pertaining to the technical field of non-acoustic underwater detection.

Abstract: Disclosed is an inverse estimation-based radius calculation method and system for ferromagnetic target detection. The calculation method includes a data acquisition step and a ferromagnetic target detection radius calculation step. Distrubance of a scale model to power frequency electromagnetic waves is used to inversely estimate a corresponding ferromagnetic target detection radius. Inverse estimation is performed separately for an air layer and a sea water layer according to test results of multiple scale model tests and in consideration of both a stationary state and a motion state of the scale model, so as to acquire a ferromagnetic target detection radius calculation formula. Weights of factors such as mass, speed, depth, and height are great in inverse estimation, so that inverse estimation precision is improved. The majority of background noise interference can be screened out of the power frequency electromagnetic waves.

Abstract: The present invention discloses an electromagnetic wave spatial analysis method based on multi-level dipole group modeling.

Abstract: A sequence time window amplitude-phase-frequency characteristics analysis method and system for underwater vehicle power frequency electromagnetic field disturbance are provided. The method includes: establishing a power grid dipole group model, emulating and calculating to obtain background field intensity data of a test location, and constructing an emulated background field database; acquiring measured background field data, comparing the emulated data with the measured data, and providing a relative error; calculating a background field intensity and underwater vehicle target disturbance under the action of the above dipole group, and establishing a measured target signal database; and performing actual measurement according to an underwater vehicle motion and detection topology, performing a Fourier transform and Fourier sliding window decomposition after acquiring original data, and acquiring an amplitude spectrum and a spectrogram of an underwater vehicle target disturbance signal.

Abstract: A time-division multiplexing control device applied to a distributed X-ray source includes: a first switch module with a number of first switches that receive a high-voltage signal and a first control signal, selectively turning on one of the plurality of first switches according to the first control signal and sending the high-voltage signal through the first switch turned on; and a cathode control module including a plurality of cathode control stages in one-to-one correspondence with the plurality of first switches, used for receiving the high-voltage signal from the first switch module and sending working state data through a cathode control stage corresponding to the first switch turned on in the plurality of cathode control stages, where each cathode control stage includes a cathode control unit and a cathode.

Abstract: A power supply circuit and a field emission electron source are provided. The power supply circuit includes: field effect transistors Si coupled in series via drains and sources in sequence, 1?i?n, i and n are natural numbers, n?2, and a source of S1 is coupled to a negative electrode of a voltage source, and a drain of Sn is used as an output terminal of the power supply circuit to couple to a load; a first group of diodes D1i coupled in series; a first group of resistors R1j, 2?j?n, and i and j are natural numbers; and a voltage control module configured to adjust an output voltage of the voltage source to cause a current passing through the load to be constant; the field effect transistors Si, 1?i?n, operate in a resistive region.

Abstract: The present invention discloses a standing wave linear accelerator, comprising: a microwave device configured to generate microwave; an electron beam emitting device configured to emit electron beam; an accelerating device configured to receive the microwave generated by the microwave device and form a microwave electric field, to accelerate electron beams generated from the electron beam emitting device and undertake the accelerated electron beam targeting to emit X ray beam; a synchronous device generating synchronous pulse signal; and a quick beam emitting device receiving the synchronous pulse signal generated by the synchronous device, wherein the microwave device runs and generates microwave in advance before the operation of the electron beam emitting device based on the synchronous pulse signal, and the quick beam emitting device drives the electron beam emitting device to emit electron beam after power of the microwave generated by the microwave device reaches stable state, so that the accelerating d

Abstract: An irradiating device and a method for controlling it are provided. The device comprises an electron accelerator and a scanning box connected to the electron accelerator, wherein the scanning box is provided with a target, an electron beam exit window positioned at left or right side of the target and a scanning magnet. The device integrates the functions of both the existing irradiating device outputting electron beams and those outputting X-rays. When the scanning magnet is in operation, the irradiating device outputs electron beams; and when the scanning magnet is not in operation, the irradiating device outputs X-rays. Therefore, the device is capable of outputting two radiation sources so as to meet requirements for radiation-processing articles with different sizes.

Abstract: A high-voltage automatic changeover switch, includes a support and a control circuit board mounted on the support. In one embodiment, the support includes an insulating frame, four high-voltage contacts mounted on each of two opposite plates of the insulating frame, four high-voltage contacts on the same plate being pair-to-pair arranged, the high-voltage contacts at the corresponding positions on the two plates being pair-to-pair arranged. A motor is provided on the support, and when switching the high voltages, the control circuit board controls the rotation of the motor to automatically switch the connection relation between the high-voltage contact pairs. Embodiments of the switch have a voltage-resistance of above 50 KV, allowing a pulse current of not less than 500 A to pass through, and good contact performance and a high stability.

Abstract: The present invention discloses a standing wave linear accelerator, comprising: a microwave device configured to generate microwave; an electron beam emitting device configured to emit electron beam; an accelerating device configured to receive the microwave generated by the microwave device and form a microwave electric field, to accelerate electron beams generated from the electron beam emitting device and undertake the accelerated electron beam targeting to emit X ray beam; a synchronous device generating synchronous pulse signal; and a quick beam emitting device receiving the synchronous pulse signal generated by the synchronous device, wherein the microwave device runs and generates microwave in advance before the operation of the electron beam emitting device based on the synchronous pulse signal, and the quick beam emitting device drives the electron beam emitting device to emit electron beam after power of the microwave generated by the microwave device reaches stable state, so that the accelerating d

Abstract: A high-voltage automatic changeover switch, includes a support and a control circuit board mounted on the support. In one embodiment, the support includes an insulating frame, four high-voltage contacts mounted on each of two opposite plates of the insulating frame, four high-voltage contacts on the same plate being pair-to-pair arranged, the high-voltage contacts at the corresponding positions on the two plates being pair-to-pair arranged. A motor is provided on the support, and when switching the high voltages, the control circuit board controls the rotation of the motor to automatically switch the connection relation between the high-voltage contact pairs. Embodiments of the switch have a voltage-resistance of above 50 KV, allowing a pulse current of not less than 500 A to pass through, and good contact performance and a high stability.

Abstract: An irradiating device and a method for controlling it are provided. The device comprises an electron accelerator and a scanning box connected to the electron accelerator, wherein the scanning box is provided with a target, an electron beam exit window positioned at left or right side of the target and a scanning magnet. The device integrates the functions of both the existing irradiating device outputting electron beams and those outputting X-rays. When the scanning magnet is in operation, the irradiating device outputs electron beams; and when the scanning magnet is not in operation, the irradiating device outputs X-rays. Therefore, the device is capable of outputting two radiation sources so as to meet requirements for radiation-processing articles with different sizes.