Abstract: The present disclosure provides a method and system for determining an optimal flight height of an unmanned aerial vehicle (UAV), an electronic device, and a medium. The method includes: obtaining a multi-band crop spectral image of an experimental area in a preset scenario; performing data processing on the multi-band crop spectral image, to obtain multi-spectral orthographies of a plurality of sample plots; calculating a ground resolution of the multi-spectral orthography of each sample plot, simulating and determining a multi-band crop spectral image of each sample plot at a different flight height by a nearest neighbor interpolation method based on the ground resolution of the multi-spectral orthography of each sample plot; and for the multi-band crop spectral image of each sample plot at the different flight height, determining an optimal flight height corresponding to each sample plot by a hypothetical test method.

Abstract: A variable region sequence of a specific antibody against clothianidin is provided. A gene encoding a heavy chain variable region of the antibody has an amino acid sequence shown in SEQ ID NO: 2. An intact recombinant antibody against clothianidin is provided. The intact recombinant antibody includes a heavy chain constant region, a heavy chain variable region, a light chain constant region and a light chain variable region, wherein a gene encoding the heavy chain variable region has an amino acid sequence shown in SEQ ID NO: 2. An immunostrip containing the antibody for rapid detection of clothianidin residue is also provided. The sequence genes obtained are linked to an expression vector containing a heavy chain constant region gene and a light chain constant region gene, respectively, and an intact recombinant antibody is expressed and obtained by using mammalian cells with a double-plasmid system.

Abstract: The present disclosure discloses a sub-module hybrid MMC with low full-bridge ratio and a DC fault processing method thereof. The hybrid MMC prevents the energy at the AC side from entering a DC system by artificially creating three-phase interphase short circuit at the AC side of a converter in the DC fault processing process, which greatly reduces the ratio of full-bridge sub-modules required for DC fault processing. Moreover, the hybrid MMC has the same DC fault processing speed as the sub-module hybrid MMC with high full-bridge. The duration of the artificially created three-phase interphase short circuit fault in the fault processing process does not exceed 30 ms, which will not have a great impact on the AC system.

Abstract: Provided is a method and system for determining plant leaf surface roughness. The method includes: acquiring a plurality of continuously captured zoomed-in leaf images by using a zoom microscope image capture system; determining a feature match set according to the zoomed-in leaf images; removing de-noised images of which the number of feature matches in feature match set is less than a second set threshold, to obtain n screened images; combining the n screened images to obtain a combined grayscale image; and determining plant leaf surface roughness according to the combined grayscale image. In the present disclosure, first, a plurality of zoomed-in leaf images are directly acquired by the zoom microscope image capture system quickly and accurately; the zoomed-in leaf images are then screened and combined to form a combined grayscale image; finally, three-dimensional roughness of a plant leaf surface is determined quickly and accurately according to the combined grayscale image.

Abstract: The present disclosure discloses a three-dimensional co-prime cubic array direction-of-arrival estimation method based on a cross-correlation tensor, mainly solving the problems of multi-dimensional signal structured information loss and Nyquist mismatch in existing methods and comprising the following implementing steps: constructing a three-dimensional co-prime cubic array; carrying out tensor modeling on a receiving signal of the three-dimensional co-prime cubic array; calculating six-dimensional second-order cross-correlation tensor statistics; deducing a three-dimensional virtual uniform cubic array equivalent signal tensor based on cross-correlation tensor dimension merging transformation; constructing a four-dimensional virtual domain signal tensor based on mirror image augmentation of the three-dimensional virtual uniform cubic array; constructing a signal and noise subspace in a Kronecker product form through virtual domain signal tensor decomposition; and acquiring a direction-of-arrival estimation

Abstract: A propulsion control device of a 3D printing-based tunnel boring machine, includes two propulsion control modules, and each of which includes tunnel support assemblies, a propulsion control assembly and a barrel body, where a propulsion sliding sleeve is arranged on an outer surface, and several tunnel support assemblies are arranged on an outer side of each propulsion sliding sleeve. Support plates on the two propulsion control modules alternately rise to support a 3D printed tunnel pipe. In the propulsion control module with the support plates in a closed state, a propulsion hydraulic cylinder controls a propulsion hydraulic cylinder extending end to contract, so as to pull the propulsion sliding sleeve to a front section of the barrel body; and in the propulsion control module with the support plates in a support state, the barrel body continuously advances relative to the propulsion sliding sleeve.

Abstract: A method for preparing a fully soft self-powered vibration sensor mainly uses a laser carbonization technology to prepare a two-dimensional porous carbon electrode with an origami structure, and then transfers the two-dimensional porous carbon electrode to a three-dimensional polydimethylsiloxane (PDMS) cavity through mold transfer; finally, a laser engraving technology is used to create microstructures on surfaces of the porous carbon electrode and a PDMS film. The sensor includes the PDMS film, a liquid metal droplet oscillator, a porous out-of-plane carbon electrode, and a 3D PDMS cavity assembled tightly from top to bottom.

Abstract: A digital detection method and system for predicting drug resistance of transgenic maize are disclosed. The method includes acquiring an RGB image, three-dimensional point cloud data and chlorophyll relative content of a maize plant after medicament spraying at a current moment; calculating a pixel ratio and morphological feature according to the RGB image and three-dimensional point cloud data; inputting a detection parameter of the maize plant at the current moment into a series model to predict the detection parameter of the maize plant at a next moment to obtain a graph of change in the detection parameter in a next period; estimating a drug resistance characteristic according to the graph of the change in the detection parameter of the maize plant; and inputting the detection parameter of the maize plant at the current moment into a parallel model to predict the variety of the maize plant.

Abstract: Disclosed are 7,7?-dihalo-3,3,3?,3?-tetramethyl-1,1?-spirobiindane and a preparation method thereof. The 7,7?-dihalo-3,3,3?,3?-tetramethyl-1,1?-spirobiindane is a compound represented by formula I, or an enantiomer, a raceme or a diastereomer thereof. The compound of formula I could be prepared by using a racemic or optically active 3,3,3?,3?-tetramethyl-1,1?-spirobiindane-6,6?-diol as a raw material through a series of reactions. The 7,7?-dihalo-3,3,3?,3?-tetramethyl-1,1?-spirobiindane is a key intermediate for preparing 3,3,3?,3?-tetramethyl-1,1?-spirobiindane-based phosphine ligand compounds represented by formula II or III.

Abstract: The present disclosure relates to the field of new materials, and aims at providing an A-site high-entropy nanometer metal oxide with high conductivity, and a preparation method thereof. The metal oxide has molecular formula of Gd0.4Er0.3La0.4Nd0.5Y0.4)(Zr0.7, Sn0.8, V0.5)O7 and is a powder, and has microstructure of the metal oxide as a square namometer sheet with a side length of 4-12 nm and a thickness of 1-3 nm. Compared with an existing high-entropy oxide, the product in the present disclosure has high conductivity, and can be well applied to a conductive alloy, an electrical contact composite material, a conductive composite material, a multifunctional bio-based composite material, a conductive/antistatic composite coating and the like.

Abstract: A single-channel wireless synchronous transmission system of energy and signal based on an integrated magnetic circuit coupling structure is provided. The system includes a direct current power supply, a high-frequency inverter circuit, a primary energy transmitter circuit, a secondary receiver circuit, a rectifier circuit, a load, a signal modulation circuit and a signal demodulation circuit. The secondary receiver circuit includes a secondary energy receiver circuit and a secondary signal receiver circuit, where an energy receiver coil and a signal receiver coil are superposed on top of each other, and the energy receiver coil and the signal receiver coil are decoupled from each other and form an integrated magnetic circuit coupling structure with a transmitter coil of the primary energy transmitter circuit.

Abstract: The present disclosure provides an apparatus and method for wavefront reconstruction based on rotationally symmetric extended structured light illumination. The apparatus includes a laser device, a neutral density filter, a microscope objective, a pinhole, a collimating lens, a beam splitter prism, a spatial light modulator, a lens to be measured, and an image acquisition device that are sequentially arranged. The method permits modulation of incident parallel light into phase grating-like structured light by using a spatial light modulator. Based on the characteristic of non-infinitely small pixel unit of the spatial light modulator, changing the modulation pattern of the spatial light modulator may result in different forms of structured light. Not only the object to be measured but also the real structured light wavefront can be recovered by acquiring diffraction spots at the focal plane and simultaneously updating the object plane and the structured light plane using an algorithm.

Abstract: Provided is a system and a method for low-temperature treatment of heavy metals and dioxins in fly ash. In the present disclosure, the fly ash is subjected to tertiary water washing and then separation by pressure filtration with a plate and frame filter press to obtain fly ash after the tertiary water washing. A low-temperature heat treatment is conducted on the fly ash after the tertiary water washing in a stirring reactor by adding an additive combination. Chlorine salts in the fly ash can be effectively removed by the tertiary water washing, which avoids the chlorination of a precursor in the fly ash to form dioxins during the low-temperature pyrolysis, thereby improving a heat reduction efficiency of the dioxins in the fly ash. Moreover, the reduction of a chlorine content in the fly ash can also avoid deactivation of the additives and improve a solidification effect of the heavy metals.

Abstract: The present invention relates to a xylitol preparation device integrating evaporation, crystallization and centrifugation, including a xylitol tank, a cleaning liquid tank, a recycling tank and a multiple distribution system, wherein the multiple distribution system includes J groups of evaporators for evaporation concentration, K groups of vacuum crystallization kettles for vacuum crystallization and L groups of centrifuges for centrifugation, wherein 2?J?6, 6?K?12 and 2?L?4; the evaporator, the vacuum crystallization kettle and the centrifuge in different groups are sequentially connected in series with one another through a pipeline and a valve respectively; by controlling on and off of each valve, a xylitol exchange liquid is switched and controlled between a series-connection mode and a parallel-connection mode in the multiple distribution system to enable evaporation, crystallization and separation processes to reach an optimal effect distribution so as to improve productivity.

Abstract: Disclosed is an environmentally-friendly method for enhancing mechanical properties of a high antibacterial nano dialysis paper for medical protection, includes following steps: a, preparing pulp components, and taking 40-60 parts of hardwood pulp, 10-20 parts of polyvinyl alcohol fiber, 30-50 parts of softwood pulp, 10-20 parts of cellulose fiber by mass; b, putting the hardwood pulp, the polyvinyl alcohol fiber, the softwood pulp and the cellulose fiber into a beater for beating to make a pulp, and then adding modified chitosan accounting for 1-5% of a weight of the pulp into the pulp, and defibering for 10-20 minutes at a rotating speed of 1500-2000 revolutions per minute in a defibrator; and c, carrying out papermaking with the pulp after defibering to form a dialysis paper finished product.

Abstract: The present invention provides a hydraulic turbine cavitation acoustic signal identification method based on big data machine learning. According to the method, time sequence clustering based on multiple operating conditions under the multi-output condition of the hydraulic turbine set is performed by utilizing an neural network, characteristic quantities of the hydraulic turbine set under a steady condition in a healthy state is screened; a random forest algorithm is introduced to perform feature screening of multiple measuring points under steady-state operation of the hydraulic turbine set, optimal feature measuring points and optimal feature subsets are extracted, finally a health state prediction model is constructed by using gated recurrent units; whether incipient cavitation is present in the equipment is judged.

Abstract: The present invention belongs to the field of array signal processing and relates to a composite tensor beamforming method for an electromagnetic vector coprime planar array. The method includes: building an electromagnetic vector coprime planar array; performing tensor modeling of an electromagnetic vector coprime planar array receiving signal; designing a three-dimensional weight tensor corresponding to a coprime sparse uniform sub-planar array; forming a tensor beam power pattern of the coprime sparse uniform sub-planar array; and performing electromagnetic vector coprime planar array tensor beamforming based on coprime composite processing of the sparse uniform sub-planar array. Starting from the principles of receiving signal tensor spatial filtering of two sparse uniform sub-planar arrays that compose the electromagnetic vector coprime planar array, the present invention forms a coprime composite processing method based on a sparse uniform sub-planar array output signal.

Abstract: A long-lasting hydrogel for use against drug-resistant bacteria, and a preparation method and use thereof are provided. In the present disclosure, polyvinyl alcohol (PVA) is mainly adopted as a matrix, and phytic acid and honey including glucose and fructose are added to modify the PVA to obtain the hydrogel. During preparation of the antimicrobial hydrogel, no toxic chemical crosslinking agent or initiator is added, and the antimicrobial hydrogel is mainly obtained by crosslinking PVA, phytic acid, and monosaccharides through ester bonds, hydrogen bonds, and electrostatic adsorption. In addition, the hydrogel obtained by adding phytic acid and honey to the PVA matrix exhibits a significant long-lasting antimicrobial effect for Staphylococcus aureus (S aureus), drug-resistant S. aureus, and Pseudomonas aeruginosa (P. aeruginosa), and the antimicrobial effect can last for about 3 months.

Abstract: The present invention discloses a pullout resistance measuring device and method based on an anchor plate foundation of a submarine slope site. The measuring device includes a support, a moving beam, a hoisting mechanism, a cylinder device, a pulley assembly, a soil sample, a spiral anchor, a traction rope and a force measuring device, where the moving beam is movably mounted on the support; the hoisting mechanism is movably mounted on the moving beam; the cylinder device includes a cylinder; the pulley assembly is movably mounted on the cylinder corresponding to the vertical slit; the soil sample is filled in the cylinder; the spiral anchor is buried in the soil sample; one end of the traction rope is connected to the hoisting mechanism, and the other end is directly connected to the spiral anchor; and the force measuring device is arranged on the traction rope.

Abstract: A three-dimensional reconstruction method based on half-peak probability density distribution, including: slicing three-dimensional point cloud along Z-axis direction to obtain N spatial layers; extracting the scatter information in i-th spatial layer and projecting information to Zi plane; constructing membership function of each grid and scatter in the Zi plane and drawing a three-dimensional probability density plot; making a plane parallel to XOY plane through half-peak wmax/2 of three-dimensional probability density plot, parallel intersecting a three-dimensional probability density plot to obtain a contour LXY; superimposing radioactive source reconstruction contours corresponding to N spatial layers sequentially to obtain a three-dimensional reconstruction model of a radioactive source.