Abstract: A random phase modulation method depending on a communication distance is provided. In the method, time synchronization is carried out by means of a transmitter and a receiver, a local random signal is generated, and an original signal to be sent is pre-coded according to a transmission delay and the generated local random signal, such that random phase modulation depending on a communication distance is realized, potential security brought about by positions of the transmitter and the receiver is fully utilized, a receiver at an expected distance position can receive a signal with a correct phase, and a receiver at another distance position receives a signal with a scrambled phase, thereby improving the secure communication capability of a wireless communication system in terms of the dimension of space.

Abstract: A power semiconductor device includes a P-type substrate, an N-type well region, a P-type body region, a gate oxide layer, a polysilicon gate, a first oxide layer, a first N+ contact region, a first P+ contact region, drain metal, a first-type doped region, and a gate oxide layer. An end of the P-type body region is flush with or exceeds an end of the polysilicon gate, wherein Cgd of the power semiconductor device is reduced and a switching frequency of the power semiconductor device is increased. A polysilicon field plate connected with a source is introduced over a drift region that is not only shield an influence of the polysilicon gate on the drift region, thereby eliminating Cgd caused by overlapping of traditional polysilicon gate and drift region, but also enable the power semiconductor device to have strong robustness against an hot carrier effect.

Abstract: A modified Ni—Ti—Ta dielectric material for multi-layer ceramic capacitor (MLCC) and a low-temperature preparation method thereof are provided. By using characteristics that radii of the Cu2+ ion and (Al1/2Nb1/2)4+ ion are close to those of Ni and Ti elements, respectively, Cu2+, Al3+ and Nb5+ ions are introduced into a Ni0.5Ti0.5TaO4 matrix for partial substitution, a negative temperature coefficient of dielectric constant of ?220±30 ppm/° C. is provided while a sintering temperature is significantly reduced, and deterioration factors of loss caused by sintering aids is reduced, so that the dielectric material applied to radio frequency MLCC with low loss, low cost and good process stability is prepared.

Abstract: A high-dimensional non-orthogonal transmission method is provided. In the method, signals of various users are mapped to form high-dimensional signals, and the high-dimensional signals are pre-coded, such that non-orthogonal transmission is realized in a higher dimension. Moreover, different users perform matched receiving on respective signals, and non-orthogonal transmission signals can be recovered merely by means of a receiver with a linear complexity. By means of the method, multi-user data non-orthogonal transmission can be realized without depending on conditions such as user pairing and collaboration, and various users do not need to perform iterative feedback, such that the detection complexity of non-orthogonal multi-user signals is significantly reduced.

Abstract: A phase domain modulation method dependent on a spatial position is provided. The method mainly includes the following steps: a transmitter and a receiver perform time synchronization to obtain a synchronization time; the transmitter performs a phase domain precoding operation on an original signal to obtain a phase domain pre-coded signal; the receiver receives the phase domain pre-coded signal, obtains a phase domain initial reception signal, and performs a phase domain matching operation on the phase domain initial reception signal to obtain an estimation of the original signal.

Abstract: A random transient power test signal generator based on three-dimensional memristive discrete map, which utilizes a three-dimensional parallel bi-memristor Logistic map module to generate two pseudo-random sequences, and based on the two pseudo-random sequences, uses two waveform output modules to generate a transient voltage signal and a transient current signal respectively, thus the random transient power testing signal is obtained.

Abstract: A method and system of two-point correction based on temperature substitution, includes: a black body related to the lens temperature is arranged outside a lens, a first black body arranged in front of the lens of an infrared thermal camera, so as to collect a gray value of the first black body; a temperature of the first black body being equal to the lens temperature; a second black body arranged in front of the lens of the infrared thermal camera, so as to collect a gray value of the second black body; a temperature of the second black body being higher than the lens temperature. Two correction parameters obtained by black body calculation related to temperature are strongly applicable, which eliminates the problem of image quality deterioration caused by temperature changes and greatly eliminates the pot lid phenomenon due to non-uniformity, thereby accurately calculating the corrected gray value.

Abstract: A wideband terahertz modulator based on gradual openings, which belongs to the technical field of electromagnetic functional devices, includes: a semiconductor substrate; an epitaxial layer provided on the semiconductor substrate; a modulation units array, a positive voltage loading electrode and a negative voltage loading electrode which are provided on the epitaxial layer; wherein each modulation unit in the modulation units array comprises a disconnected H-shaped structure, a metal electrode located below an end of the opening of the disconnected H-shaped structure, and a semiconductor doped heterostructure located below the opening of the disconnected H-shaped structure; wherein in the disconnected H-shaped structures, adjacent modulation units have different opening positions; in a same row, the opening positions are linearly distributed and have a certain slope, and inclination slopes of the opening positions of two adjacent rows are opposite.

Abstract: A room-temperature semiconductor maser, including a first matching network, a second matching network, a heterojunction-containing transistor, and a resonant network. The output end of the first matching network is connected to the drain of the heterojunction-containing transistor. The input end of the second matching network is connected to the source of the heterojunction-containing transistor. The gate of the heterojunction-containing transistor is connected to the resonant network. The pumped microwaves are fed into the input end of the first matching network.

Abstract: A four-shaft panoramic scanning temperature measuring device with a circulating water-cooling device is provided, which not only improves the working reliability of the probe, but also increases the overall flexibility and scanning measurement efficiency. The circulating water-cooling device is self-cooled. Compared with the conventional single-circulation water-cooling way, the design of five cooling cavities can achieve higher circulating water-cooling efficiency. The four-shaft structure includes a shaft structure for translation, a shaft structure for rotation, a shaft structure for swinging, and a shaft structure with coaxial sight pipe and light pipe. The design of the four-shaft structure is able to panoramically scan the high-temperature components inside the turbine. The temperature measuring device integrates functions of cooling, swinging, translating and rotating together, which solves problems of large size and complex control of the conventional temperature measuring device.

Abstract: A termination structure of a super-junction power device has a novel polysilicon resistive field plate at the top of a termination region between a transition region and an edge of the device. By utilizing the regular distribution of potential in the field plate, an additional electric field is introduced at the top of the termination structure to limit the expansion of a non-depletion region and optimize the distribution of charges. The termination structure includes a first doping type epitaxial layer, a second doping type compensation region, a second doping type body region, a second doping type lateral connection layer, a second doping type body contact region, a first doping type source contact region, a gate oxide layer, a passivation layer, a field oxide layer, a gate electrode, a second doping type edge contact region, a polysilicon resistive field plate, a metal layer and the like.

Abstract: The present disclosure relates to a method for recognizing facial expressions based on adversarial elimination. First, a facial expression recognition network is built based on a deep convolutional neural network. On a natural facial expression data set, the facial expression recognition network is trained through a loss function to make facial expression features easier to distinguish. Then some key features of input images are actively eliminated by using an improved confrontation elimination method to generate a new data set to train new networks with different weight distributions and feature extraction capabilities, forcing the network to perform expression classification discrimination based on more features, which reduces the influence of interference factors such as occlusion on the network recognition accuracy rate, and improving the robustness of the facial expression recognition network.

Abstract: The disclosure relates to a wireless self-powered gas sensor based on electromagnetic oscillations triggered by external forces and its fabrication method. The sensor includes a gas test chamber, a first friction layer, a second friction layer, an interdigital electrode, a gas-sensitive material, an air inlet, an air outlet and leads. The gas sensor of the disclosure is an integrated detection system of “environmental energy collection—wireless energy transmission—active spontaneous detection” that can be driven simultaneously only by external mechanical movement, and can work independently without external power supply. The first friction layer and the second friction layer are arranged outside the gas test chamber. The frictional motion will not interfere with the flow field of the test chamber and the gas molecule absorption and desorption, which ensures the stability of gas detection to the greatest extent.

Abstract: Robot assisted multi-view 3D scanning measurement based on path planning includes firstly, establishing a virtual simulation platform to complete the setting of measurement poses and measurement paths and perform the path evaluations of measurement paths. Then, completing the preliminary hand-eye calibration based on the properties of Kronecker product, and the preliminary hand-eye calibration is optimized by establishing a reprojection error cost function as the fitness function of the particle swarm optimization algorithm. Lastly, moving the robot to the measurement poses of the planned measurement paths, obtaining a single-view point cloud of the measured object and transforming it from the camera coordinate system to the robot base coordinate system to obtain a registered single-view point cloud based on the optimized hand-eye matrix.

Abstract: Provided is a passive wireless magnetic field characteristic sensing tag and system, and a magnetic field quantity acquisition method, which integrates a passive magnetic field quantity sensor in a passive electronic tag and cooperates with a reader and a host computer to build a magnetic field sensing system, so as to realize high-precision and high-intelligence monitoring of the magnetic field quantity.

Abstract: A dynamic network resource allocation method based on network slicing is provided. A historical resource demand dataset of an accessed network slice is inputted into a first neural network for training. Based on a trained first neural network and the historical resource demand of the accessed network slice, a resource demand prediction information corresponding to the accessed network slice in a first prediction time period is determined. Resources are pre-allocated to the accessed network slice based on the resource demand prediction information, and resources are allocated to the accessed network slice when the first prediction time period arrives. In this way, the service provider can reasonably allocate network resources for network slices without violating the SLA, thus avoiding the waste of network resources.

Abstract: A network emulation system supporting a flexible and efficient dynamic experiment emulates a network based on container, veth-pair, traffic control (TC), and other technologies and sets a network state management model based on a key-value pair, thereby constructing a network emulation system supporting a flexible and efficient dynamic experiment. The system flexibly realizes the dynamic performance of a plurality of dimensions, namely, dynamic node start/stop, dynamic node attribute configuration, dynamic link start/stop, and dynamic link attribute configuration. Based on the network state management model, the network emulation system provides a concise and unified dynamic application programming interface (API) for an upper layer. Researchers can call the API in their network innovation programs at any time after an emulation network is deployed to achieve efficient, batch-processing, and programmable dynamic management.

Abstract: A multi-level gate driver applied to the SiC metal-oxide-semiconductor field-effect transistor (MOSFET) includes three parts: the SiC MOSFET information detection circuit, the signal level shifting circuit, and the segmented driving circuit. The SiC MOSFET information detection circuit includes the SiC MOSFET drain-source voltage detection circuit and the SiC MOSFET drain-source current detection circuit. The segmented driving circuit includes a turn-on segmented driving circuit and a turn-off segmented driving circuit.

Abstract: The present disclosure discloses an MXene-based terahertz wave broadband super-strong absorbing foam, and belongs to the technical field of electromagnetic functional materials. The MXene-based terahertz wave broadband super-strong absorbing foam includes a porous polymer foam and a MXene nanosheet attached onto the porous polymer foam, wherein the MXene nanosheet is attached onto the porous polymer foam in a coating form, a film forming form and a suspension form; the average pore diameter of the porous polymer foam ?500 ?m, the thickness of the porous polymer foam ?10 mm, and the filling mass of the MXene nanosheet is less than 50% of the mass of the absorbing foam.

Abstract: The disclosure provides a self-biased magneto-optical non-reciprocal metasurface device. The device includes substrate layer and a sub-wavelength structure layer. The substrate layer is a material layer with a refractive index of 1 to 5 in a microwave frequency band. The sub-wavelength structure layer includes a plurality of square columnar elements arranged in a matrix period with equal period in row and column directions. The square columnar elements include magneto-optical material. The adjustment of phase and amplitude of a circularly polarized electromagnetic wave is achieved by changing the length, width and height of the square columnar elements, and thus the device attains a desired isolation and insertion loss at a center frequency f0. The parameters of the magneto-optical material are: coercivity Hc?1000 A/m; remanence Br?1 kGs; a voigt parameter of a permittivity tensor or permeability tensor in a working frequency band?0.01.