Abstract: The disclosure discloses a polycrystalline diamond composite sheet having a continuous gradient transition layer and a 3D printing preparation method thereof. The polycrystalline diamond composite sheet consists of a polycrystalline diamond layer, a continuous gradient transition layer, and a cemented carbide substrate from top to bottom, in which the continuous gradient transition layer consists of diamond and cemented carbide. Along a direction from the cemented carbide substrate to the polycrystalline diamond layer, a content of the cemented carbide in the continuous gradient transition layer decreases from 100% to 0, and a content of the diamond increases from 0 to 100%. By designing and combining the continuous gradient transition layer with 3D printing technology, the disclosure realizes a continuous change in the two materials of diamond and cemented carbide, thereby eliminating the sudden change interface of the materials inside the diamond composite sheet.

Abstract: Embodiments of the present disclosure are directed to a system for monitoring moving and stepping silicon wafers and a method adopts the system. The system includes a first sensing element to monitor whether a gap between adjacent silicon wafers exists, and a second sensing element to monitor whether two silicon wafers are laminated. The first sensing element and the second sensing element are both disposed in a slot where the silicon wafers are turned over, and suspended on a front side of a sorting wheel in the slot and obliquely arranged towards one side of the sorting wheel. The system installed in the narrow space between the cleaning tank and the sorting tank has simple structure and is capable of quickly and accurately monitoring the silicon wafer turnover, and accurately determining whether there is a continuous or laminated silicon wafer during the silicon wafer turnover process.

Abstract: The disclosure discloses a polycrystalline cubic boron nitride composite sheet having a continuous gradient structure and a preparation method thereof. The polycrystalline cubic boron nitride composite sheet consists of a cemented carbide substrate, a continuous gradient layer, and a CBN layer from bottom to top. The continuous gradient layer contains cemented carbide and CBN, a content of CBN increases in continuous gradient from bottom to top, while a content of the cemented carbide decreases in continuous gradient from bottom to top. A volume fraction D of CBN and a volume fraction M of cemented carbide in the continuous gradient layer both satisfy exponential gradient functions. At the same time, the disclosure uses direct ink writing 3D printing technology with slurry to realize the preparation of the polycrystalline cubic boron nitride composite sheet having the continuous gradient structure.

Abstract: A method for discovering an unexploded ordnance in a target area includes: acquiring first feedback signals respectively corresponding to detection regions, the first feedback signals being first induced electromotive force signals; judging whether there is any abnormal signal in the first feedback signals, if there is the abnormal signal, determining the detection region corresponding to the abnormal signal is an abnormal region; acquiring second feedback signals respectively corresponding to detection sites in the abnormal region, the second feedback signals being magnetic field gradient signals; acquiring third feedback signals respectively corresponding to the detection sites, the third feedback signals being second induced electromotive force signals; acquiring location information of the detection sites; obtaining a feature spatial distribution map of the abnormal region; and judging whether there is any unexploded ordnance in the abnormal region according to the feature spatial distribution map.

Abstract: A detection method for discovering an unexploded ordnance includes: surrounding a detection region with a transmitting coil and surrounding a detection site with a second receiving coil; conducting the transmitting coil with a second electric current; respectively acquiring a plurality of second feedback signals at a plurality of second feedback time points; partitioning the transmitting coil into a plurality of dipoles, and acquiring a plurality of distance values r respectively between the plurality of dipoles and the detection site; respectively calculating feedback depths according to feedback time periods; respectively calculating apparent resistivity values corresponding to the feedback depths; obtaining an apparent resistivity distribution in depth at the detection site according to the apparent resistivity values and the feedback depths; and judging whether there is any unexploded ordnance at the detection site according to the apparent resistivity distribution in depth.

Abstract: A magnetism detection apparatus includes a detection device, at least one first locating device, and a central control device. The detection device includes an array of detection assemblies arranged in a same plane. The array of detection assemblies is configured to detect magnetic fields and output magnetic field signals corresponding to locations of the detection assemblies. The at least one first locating device is disposed on one of the detection assemblies to locate this detection assembly and output a first coordinate signal corresponding to this detection assembly. The central control device is communicatively and respectively connected to each of the detection assemblies and the at least one first locating device, and configured to process the magnetic field signals and the first coordinate signal.

Abstract: A method for collecting and processing terahertz spectral imaging data includes: scanning an object to generate terahertz spectral data having a hyper- or low-spectral resolution respectively at a plurality of pixel points; collecting the terahertz spectral data and recording coordinate data of each pixel point, thereby obtaining a mixed data including a hyper-spectral data and a low-spectral data corresponding to different pixel points; constructing a hyper-spatial and low-spectral imaging data-cube from the mixed data; extracting a hyper-spectral data-set from the mixed data; and reconstructing a hyper-spatial and hyper-spectral imaging data-cube from the hyper-spatial and low-spectral imaging data-cube based on the hyper-spectral data-set. A terahertz spectral imaging apparatus is further provided.

Abstract: An amphibious portable magnetism detector includes a first housing, a first wiring tube, a first magnetic field sensor, and a central control device. The first housing defines a first inner space and a first through hole in communication with the first inner space. The first wiring tube is connected to the first housing with a first leak-tight seal formed between them, and in communication with the first inner space via the first through hole. The first magnetic field sensor is disposed in the first inner space and configured to detect a magnetic field at a target area and generate a first detection signal. The central control device is electrically connected to the first magnetic field sensor and configured to receive the first detection signal and output a first magnetic field value according to the first detection signal.

Abstract: A hybrid cascaded APF topology and control method therefor for improving the ability of a system to compensate for higher harmonics, raise the quality of electric energy of output currents, and reduce costs. The topology includes: a three-phase cascaded H-bridge including bridge arms of three phases, each bridge arm including a plurality of H-bridge cells connected in series, and the bridge arms of the three phases connected to a power system needing active filtering via inductors; and a three-phase H-bridge circuit connected at star connection points of the three-phase cascaded H-bridge, the three-phase H-bridge circuit including branches of the three phases and two capacitors connected in parallel across the branches of the three phases, and the branch of each phase including two switching transistors connected in series, where switching transistors of the H-bridge cells use Si devices, and the switching transistors of the three-phase H-bridge circuit use SiC devices.

Abstract: The present application provides a terahertz spectral imaging data reconstruction method, an apparatus, a device, and a storage medium. The method includes: scanning a target object according to the first spatial interval and the first time domain sampling period to acquire the first terahertz spectral data; scanning the target object according to the second spatial interval and the second time domain sampling period to acquire the second terahertz spectral data, the first spatial interval is larger than the second spatial interval, and the first time domain sampling period is larger than the second time domain sampling period; and reconstructing the second terahertz spectral data on basis of the first terahertz spectral data by using the preset reconstruction method to obtain the third terahertz spectral data.

Abstract: A gas detecting apparatus and a gas detecting method based on terahertz spectroscopy are provided. The apparatus includes a sample chamber allowing a terahertz wave to pass therethrough; a gas feeding unit connected to the sample chamber to feed gas into the sample chamber; a gas outputting unit connected to the sample chamber to output gas from the sample chamber; and a vacuum pump connected to the sample chamber to evacuate the sample chamber. The apparatus further comprises one or more of a pressure gauge disposed on the sample chamber, an anemometer disposed on the sample chamber, a humidity regulation device connected to the sample chamber, and a temperature regulation device connected to the sample chamber.

Abstract: A hybrid cascaded APF topology and control method therefor for improving the ability of a system to compensate for higher harmonics, raise the quality of electric energy of output currents, and reduce costs. The topology includes: a three-phase cascaded H-bridge including bridge arms of three phases, each bridge arm including a plurality of H-bridge cells connected in series, and the bridge arms of the three phases connected to a power system needing active filtering via inductors; and a three-phase H-bridge circuit connected at star connection points of the three-phase cascaded H-bridge, the three-phase H-bridge circuit including branches of the three phases and two capacitors connected in parallel across the branches of the three phases, and the branch of each phase including two switching transistors connected in series, where switching transistors of the H-bridge cells use Si devices, and the switching transistors of the three-phase H-bridge circuit use SiC devices.

Abstract: The present disclosure provides a waveguide-excited terahertz microstrip antenna. The antenna includes a dielectric substrate, a ground plate, a rectangular waveguide, a metal pin, and a radiation patch. The dielectric substrate has a first surface and a second surface opposite to the first surface. The ground plate is located on the first surface of the dielectric substrate and defines a coupling slit. The rectangular waveguide is located on a surface of the ground plate away from the dielectric substrate and extended substantially along a first direction parallel to the first surface. The metal pin is located inside the rectangular waveguide, and is in contact with the ground plate and substantially perpendicular to the ground plate. The radiation patch is located on the second surface of the dielectric substrate.

Abstract: A method for discovering an unexploded ordnance in a target area includes: acquiring first feedback signals respectively corresponding to detection regions, the first feedback signals being first induced electromotive force signals; judging whether there is any abnormal signal in the first feedback signals, if there is the abnormal signal, determining the detection region corresponding to the abnormal signal is an abnormal region; acquiring second feedback signals respectively corresponding to detection sites in the abnormal region, the second feedback signals being magnetic field gradient signals; acquiring third feedback signals respectively corresponding to the detection sites, the third feedback signals being second induced electromotive force signals; acquiring location information of the detection sites; obtaining a feature spatial distribution map of the abnormal region; and judging whether there is any unexploded ordnance in the abnormal region according to the feature spatial distribution map.

Abstract: A fluxgate detector for buried and abandoned chemical weapons is provided, comprising: a probe for sensing an external magnetic field, comprising a probe input and a probe output; an excitation module electrically connected to the probe input for inputting an excitation signal into the probe; a frequency selection module electrically connected to the probe output for isolating a second harmonic signal in an induced voltage generated by the probe; and a signal acquisition module electrically connected to the frequency selection module. The second harmonic signal in the induced voltage can be isolated by the frequency selection module, transmitted to the signal acquisition module, and converted to an intensity of the magnetic field by the signal acquisition module. The substance detected can be identified according to the intensity of the magnetic field, so that the buried ACWs can be found efficiently and accurately.

Abstract: The present application provides a terahertz spectral imaging data reconstruction method, an apparatus, a device, and a storage medium. The method includes: scanning a target object according to the first spatial interval and the first time domain sampling period to acquire the first terahertz spectral data; scanning the target object according to the second spatial interval and the second time domain sampling period to acquire the second terahertz spectral data, the first spatial interval is larger than the second spatial interval, and the first time domain sampling period is larger than the second time domain sampling period; and reconstructing the second terahertz spectral data on basis of the first terahertz spectral data by using the preset reconstruction method to obtain the third terahertz spectral data.

Abstract: A detection method for discovering an unexploded ordnance includes: surrounding a detection region with a transmitting coil and surrounding a detection site with a second receiving coil; conducting the transmitting coil with a second electric current; respectively acquiring a plurality of second feedback signals at a plurality of second feedback time points; partitioning the transmitting coil into a plurality of dipoles, and acquiring a plurality of distance values r respectively between the plurality of dipoles and the detection site; respectively calculating feedback depths according to feedback time periods; respectively calculating apparent resistivity values corresponding to the feedback depths; obtaining an apparent resistivity distribution in depth at the detection site according to the apparent resistivity values and the feedback depths; and judging whether there is any unexploded ordnance at the detection site according to the apparent resistivity distribution in depth.

Abstract: A fluxgate detector for buried and abandoned chemical weapons is provided, comprising: a probe for sensing an external magnetic field, comprising a probe input and a probe output; an excitation module electrically connected to the probe input for inputting an excitation signal into the probe; a frequency selection module electrically connected to the probe output for isolating a second harmonic signal in an induced voltage generated by the probe; and a signal acquisition module electrically connected to the frequency selection module. The second harmonic signal in the induced voltage can be isolated by the frequency selection module, transmitted to the signal acquisition module, and converted to an intensity of the magnetic field by the signal acquisition module. The substance detected can be identified according to the intensity of the magnetic field, so that the buried ACWs can be found efficiently and accurately.

Abstract: A gas detecting apparatus and a gas detecting method based on terahertz spectroscopy are provided. The apparatus includes a sample chamber allowing a terahertz wave to pass therethrough; a gas feeding unit connected to the sample chamber to feed gas into the sample chamber; a gas outputting unit connected to the sample chamber to output gas from the sample chamber; and a vacuum pump connected to the sample chamber to evacuate the sample chamber. The apparatus further comprises one or more of a pressure gauge disposed on the sample chamber, an anemometer disposed on the sample chamber, a humidity regulation device connected to the sample chamber, and a temperature regulation device connected to the sample chamber.

Abstract: A method for collecting and processing terahertz spectral imaging data includes: scanning an object to generate terahertz spectral data having a hyper- or low-spectral resolution respectively at a plurality of pixel points; collecting the terahertz spectral data and recording coordinate data of each pixel point, thereby obtaining a mixed data including a hyper-spectral data and a low-spectral data corresponding to different pixel points; constructing a hyper-spatial and low-spectral imaging data-cube from the mixed data; extracting a hyper-spectral data-set from the mixed data; and reconstructing a hyper-spatial and hyper-spectral imaging data-cube from the hyper-spatial and low-spectral imaging data-cube based on the hyper-spectral data-set. A terahertz spectral imaging apparatus is further provided.