Abstract: A high-gain and low-RCS (radar cross section) broadband circularly polarized metasurface antenna based on a novel sequential-rotation feeding network includes three layers of dielectric substrates and five metal layers as well as three resistors, which are from top to bottom: a first metal layer, a first dielectric substrate, a second metal layer, a second dielectric substrate, a third metal layer, a fourth metal layer, a third dielectric substrate and a fifth metal layer. The first three metal layers are all metasurface arrays composed of 10*10 metal patches; the fourth metal layer and the third metal layer define a resonant cavity by means of a distance therebetween; the fourth metal layer is provided with four slits having rotational symmetry; and the fifth metal layer is a hybrid feeding network composed of microstrip lines and including three equal power dividers and three resistors.

Abstract: A low-temperature airflow follow-up auxiliary sand discharge apparatus for cutting a frozen sand mold includes a frozen sand mold to be machined, a hollow cutter, a spindle mounted on the hollow cutter, an air pipe, and a refrigeration apparatus connected to one end of the air pipe. The refrigeration apparatus is fixed to an air pump by a valve. An inner cavity of the hollow cutter is provided with a cutter through hole along an axis. An inner cavity of the spindle is provided with a spindle through hole along the axis. An upper end of the spindle is provided with a bearing seat hole for placing a bearing. An outer circle of the bearing matches the bearing seat hole, and an inner circle of the bearing is mounted with an air pipe connector. The air pipe is connected and fixed to the air pipe connector.

Abstract: The present disclosure provides an electrochemical machining device and a method for a blisk using an electrode array, which relate to the technical field of electrochemical machining. The electrochemical machining device comprises an outer ring-shaped rotating ring, an inner ring-shaped base and a plurality of cathode rods. An inner diameter of the outer ring-shaped rotating ring is larger than an outer diameter of the inner ring-shaped base, and an inner diameter of the inner ring-shaped base is larger than an outer diameter of the blisk. The outer ring-shaped rotating ring and the inner ring-shaped base are coaxially arranged. Middle parts of the cathode rods are connected with the inner ring-shaped base, outer ends of the cathode rods are rotatably connected with the outer ring-shaped rotating ring, and inner ends of the cathode rods are provided with trepanning cathode pieces or radial feeding electrodes.

Abstract: A flat-plate water-heating photovoltaic/thermal module and a production process thereof are disclosed. The flat-plate water-heating photovoltaic/thermal module includes a frame. The lower surface of the frame is provided with a heat preservation back plate. The upper surface of the frame is sequentially laminated with a glass cover plate, a first photovoltaic cell laminating adhesive, a photovoltaic cell slice, a second photovoltaic cell laminating adhesive, a transparent back plate, a third photovoltaic cell laminating adhesive and a heat absorbing component from top to bottom. A heat preservation cavity is formed between the heat preservation back plate and the heat absorption part.

Abstract: A method for small object detection in drone scene based on deep learning is provided, which includes: inputting images captured by a drone into a pre-trained generator based on an Unet network structure to output normal-light images; inputting the normal-light images into a object detection backbone network to output a plurality of multidimensional matrix feature maps, wherein the object detection backbone network integrates a channel attention mechanism and a spatial attention mechanism based on convolutional block Self-Block, and a 7*7 large convolutional kernel is used; inputting the plurality of multidimensional matrix feature maps into a BiFPN-S module of a feature pyramid for feature fusion, so as to output a plurality of corresponding feature maps for predicting objects of different sizes.

Abstract: The invention discloses a three-dimensional (3D) measurement method based on end-to-end deep learning for speckle projection. First, the speckle pattern was projected by the projector and collected simultaneously by the stereo camera. The speckle images after stereo rectification are fed into the stereo matching network. A feature extraction sub-network based on shared weights processes the speckle images to obtain a series of low-resolution 3D feature tensors, The feature tensor is fed into the saliency object detection sub-network to detect foreground information in the speckle images, producing a full-resolution valid mask map. A 4D matching cost volume is generated using the feature tensor of both views based on the candidate disparity range, filtered by a series of 3D convolutional layers to achieve cost aggregation, so that the initial disparity map is obtained by disparity regression.

Abstract: The present disclosure discloses a trans-media unmanned aerial vehicle device and a control method thereof. The trans-media unmanned aerial vehicle device includes a housing, and a piston which is arranged in the housing and is capable of moving in a reciprocating manner in the housing; one end of the housing is provided with an opening; several flying wings are uniformly arranged in a circumferential direction of the piston; the flying wings are rotatably connected to a side of the piston facing the opening and are spread or retracted like an umbrella; and under the pushing of the piston, the flying wings can be spread to the outside of the housing and retracted back into the housing.

Abstract: The present invention discloses an experimental apparatus and experimental method for physical modeling of lithospheric structural deformation. The experimental apparatus comprises a drum centrifuge capsule, a drum centrifuge driving power compartment, a structural deformation device control system and a motion control system; a basket is hung at each end of a cantilever of the centrifuge, a structural deformation experiment box is placed in the basket, and the structural deformation control system accurately controls the deformation of experimental materials in the experiment box and can model structural deformation processes at various lithospheric scales. The experimental apparatus further comprises real-time monitoring cameras and a high-speed image acquisition device.

Abstract: It discloses an experimental apparatus and experimental method for physical modeling of a fluid migration and accumulation process with contemporaneous structural deformation. The experimental apparatus comprises a structural deformation experiment box, a structural deformation control device, a fluid control device and an experimental control device; the structural deformation experiment box is installed in a basket experiment module on a cantilever of a drum centrifuge, the structural deformation control device can extend and compress an experimental model in horizontal and vertical directions; and fluid cylinders of the fluid control device can be filled with fluids or plastic materials.

Abstract: A high-temperature disaster forecast method based on a directed graph neural network is provided, and the method includes the following steps: S1, performing standardization processing on meteorological elements respectively to scale the meteorological elements into a same value range; S2, taking the meteorological elements as nodes in the graph, and describing relationships among the nodes by an adjacency matrix of graph; then learning node information by a stepwise learning strategy and continuously updating a state of the adjacency matrix; S3, training the directed graph neural network model after determining a loss function, obtaining a model satisfying requirements by adjusting a learning rate, an optimizer and regularization parameters as a forecast model, and saving the forecast model; and S4, inputting historical multivariable time series into the forecast model, changing an output stride according to demands, and thereby obtaining high-temperature disaster forecast for a future period of time.

Abstract: An identification method of urban functional areas based on mixing degree of functions and integrated learning includes the following steps: 1) performing data acquisition and preprocessing; 2) constructing 10 indicator features of an urban functional area identification system; 3) structuring the indicator features: acquiring, by a spatial statistical tool, the 10 indicator features corresponding to each parcel; 4) constructing an independent variable dataset; 5) labeling response variables; 6) dividing a training dataset into a plurality of training subsets according to the mixing degree of functions; 7) training a Stacking-based integrated learning model; and 8) joining an attribute in one table to another table, so as to complete the identification of the urban functional areas on each parcel. The identification method divides the training dataset by grading the mixing degree of functions, and makes predictions based on the prediction dataset with corresponding mixing degree of functions.

Abstract: The present disclosure discloses a method for removing chlorinated hydrocarbons in groundwater through step-by-step electrocatalytic dechlorination degradation. A double-chamber electrolyzer reactor is used to carry out step-by-step electrocatalytic dechlorination degradation to remove chlorinated hydrocarbons in groundwater. The double-chamber electrolyzer reactor comprises a cathode chamber, a proton exchange membrane, an anode chamber and an intermediate processing unit, wherein the cathode chamber is separated from the anode chamber through the proton exchange membrane, and the intermediate processing unit is connected between the cathode chamber and the anode chamber through a cathode chamber water outlet, an anode chamber water inlet and pipelines.

Abstract: A system for cleaning wastewater, includes: an absorption-biodegradation-denitrification (ABN) reactor, a sequential adsorption reactor, a disinfection reactor, and a sludge anaerobic fermentation reactor. The ABN reactor is an integrated reactor including: a biosorption tank, an intermediate sedimentation tank, a biologically-enhanced degradation tank, a denitrification biofilter, and a secondary sedimentation tank. The pretreated wastewater is introduced into the ABN reactor for removal of chemical oxygen demand, nitrogen and phosphorus; the ABN reactor effluent is introduced into the sequential adsorption reactor for the removal of high-risk pollutants; the sequential adsorption reactor effluent is introduced into the disinfection reactor for the elimination of viruses and other pathogenic microorganisms; the sludge produced by the ABN reactor is introduced into the anaerobic sludge fermentation reactor for alkaline fermentation.

Abstract: A self-heterodyne phase-sensitive optical time domain reflectometry (?-OTDR) system with a free multi-spatial resolution includes a narrow linewidth laser source, a 1×3 fiber-optic coupler, three acousto-optic modulators (AGMs), a 3×1 fiber-optic coupler, two time-delay fibers, an erbium-doped fiber amplifier (EDFA), a circulator, a photodetector, an electrical amplifier, three filters, a data acquisition card, a pulse signal generator, and a driver module. A plurality of acousto-optic modulators using the same driver are used to couple probe light with different pulse intervals and different frequency shifts and then inject the probe light into a fiber, such that a self-heterodyne detection structure with a multi-spatial resolution is implemented, which suppressed optical background noise such as coherent fading noise, phase noise introduced by a frequency drift of a light source, and pseudo-random noise (PRN).

Abstract: Disclosed are a drive-by-wire chassis cyber-physical system under an intelligent traffic environment and a control method. The system includes: an SoS-level CPS, a system-level CPS, and a unit-level CPS, data transmission is realized between a plurality of unit-level CPSs and one system-level CPS, and data transmission is realized between a plurality of system-level CPSs and one SoS-level CPS. The system integrates a hub motor with a suspension, cancels traditional structures such as an engine and a clutch, and simplifies the structure of a chassis. A motor directly drives a vehicle to run, and different driving, braking or torque is applied to different wheels through four hub motors, so as to meet independent control of the wheels and improve active safety and operational stability.

Abstract: A networked control method for primary frequency regulation of a new energy power station based on a source-grid-load-storage networked cloud decision control system platform comprises: determining, according to historical operating data of a new energy power station, primary frequency regulation predictive values of power generation units of the new energy power station; determining, according to the primary frequency regulation predictive values, optimal control sequences of inverters of the power generation units at different times based on a pre-established inverter active power model, wherein the optimal control sequences comprise multiple control quantities of active power of the inverters; marking the optimal control sequences at the different times with time scales, sending the optimal control sequences to executing devices of the power generation units, receiving the optimal control sequences, and determining whether to store or not store the optimal control sequences; and determining the control qua

Abstract: A multi-view outlier detection algorithm based on the tensor representation is provided. Specifically, the multi-view data are firstly transformed into a set of tensors, and then its low-rank representation is learned. Finally, an outlier function is designed in the case of tensor representation to realize detection.

Abstract: The present disclosure relates to a method and system for detecting a structural defect in additive manufacturing. The method includes: layering a three-dimensional model of an additive manufacturing test piece to obtain a two-dimensional contour of an interface of each layer, and generating a machining path; arranging a non-contact sensor at a fixed measuring point of the additive manufacturing test piece, and acquiring an ultrasonic signal at each machining point when a pulse laser conducts machining point by point along the machining path; forming a visual ultrasonic field based on all the ultrasonic signals, and determining ultrasonic field data; determining, based on the ultrasonic field data, a curve of a peak of an incident wave changing with the machining path; and determining whether a machining defect exists at the machining points based on the curve of the peak of the incident wave changing with the machining path.

Abstract: An interrupt-driven system verification method based on interrupt sequence diagrams includes the steps of: establishing an interrupt-driven system model based on an interrupt sequence diagram, dividing interaction fragments in the obtained interrupt sequence diagram into basic interaction fragments and composite interaction fragments and sequentially converting the basic interaction fragments and the composite interaction fragments into the corresponding automaton models, combining the automaton models into one automaton model, adding the constraints in the interrupt sequence diagram to the converted automaton model, adding the verification attribute information as a constraint to the converted automaton model, describing an automaton as an input format acceptable to the automaton verification tool, and verifying the model with the automaton verification tool.

Abstract: This invention proposes a single-vector-based finite control set model predictive control for two parallel power converters, which adopts a centralized control structure to achieve accurate control of overall performance. It establishes predictive models for line currents and three phase-circulating currents and constructs a novel cost function that uses these currents as performance indices to implement the predictive control algorithm based on the proposed predictive models. The invention proposes dynamic weighting coefficients and adjustment principles to improve system control performance. A finite set output signal matrix containing important characteristic information of all alternative vectors is constructed to avoid redundant calculations in each control horizon, reducing computation time during practical implementation.