Abstract: Provided by the present invention is a cathode material for a sodium-ion battery with a coating structure and a preparation method therefor. In the present invention, an Na3V2(PO4)3/C cathode material is prepared by means of a sol-gel method. Synthesized zwitterionic polymers may be used as chelating agents and as a carbon source; the process is simple, can quickly form a gel, and the reaction time is shortened contains a zwitterionic structure which may be well dissolved with the precursor of sodium vanadium phosphate to form a stable carbon coating layer. Compared to the prior art, the cathode material for a sodium-ion battery of the present invention enhances the electrical conductivity and cycle performance of the cathode material by means of the doping of nitrogen and sulfur on carbon. At the same time, the prepared cathode material for a sodium-ion battery has sodium vacancies and maintains a stable structure during the process of sodium-ion intercalation/deintercalation.

Abstract: A method and system for cross-technology communication from a WiFi device to a ZigBee device includes: generating, by a WiFi transmitter, to-be-transmitted symbol-level energy modulation bits information simultaneously carrying WiFi data bits and cross-technology data bits transmitted to the ZigBee device, wherein the cross-technology data bits are obtained based on symbol-level energy modulation; and a ZigBee receiver processing received signal strength indication sample information and initiating a cross-technology communication receiving process to obtain the cross-technology data bits needing to be received, and meanwhile a WiFi receiver obtaining the to-be-transmitted symbol-level energy modulation bits information through a standard WiFi receiving process, and then initiating a WiFi data recovery process to obtain original WiFi data bits.

Abstract: A system for detecting metal stamping part tapping defects, which comprises a product placing device, a detecting mechanism, a defective product sorting mechanism, a good product discharging mechanism, an analyzing mechanism and a Programmable Logic Control (PLC) system; the product placing device, the defective product sorting mechanism, and the good product discharging mechanism are connected to the PLC system respectively, the PLC system is configured to control the product placing device to place the metal stamping part in a detection position; the detecting mechanism is configured to acquire the tapping hole information of the metal stamping part tapping hole in the detection position.

Abstract: A metal-insulator-metal (MIM) high-sensitivity plasmon polariton (SPP) terahertz wave detector includes a rectangular cavity, an absorption cavity, a silver block, two waveguides, three metal films, a terahertz probe light, a signal light, and an opto-electric detector; the terahertz probe light is located at an upper end of the rectangular cavity; the rectangular cavity is located at an input end of the terahertz probe wave; and the absorption cavity is connected with a first waveguide; the silver block is disposed within the first waveguide, and is movable; and the first waveguide is connected with a second waveguide.

Abstract: The present disclosure provides a preparation method of a shape memory polyurethane, which comprising: reacting 1,3,5,7-tetrahydroxyadamantane, ?-caprolactone, a catalyst and a solvent for 20-50 hours under the conditions of inert gas and 70° C. to 130° C. to obtain adamantyl star poly(?-caprolactone), wherein the mole ratio of the 1,3,5,7-tetrahydroxyadamantane to the ?-caprolactone is 1:(40-240); mixing the adamantyl star poly(?-caprolactone) with long-chain diol and diisocyanate, adding the catalyst and the solvent, and reacting for 3-9 hours at 50-100° C. to obtain an isocyanate-terminated polyurethane prepolymer, wherein the mass ratio of the adamantyl star poly(?-caprolactone) to the long-chain diol is 9:1-1:9; and adding a linking agent in the polyurethane prepolymer so that the linking agent reacts with isocyanate in the polyurethane prepolymer to obtain an adamantyl cross-linked shape memory polyurethane.

Abstract: A whispering gallery mode resonator and a manufacturing method includes a hollow core fiber, a waveguide, a waveguide resonant cavity, a first single-mode fiber and a second single-mode fiber. The waveguide and the waveguide resonant cavity are located in the hollow core fiber. End surface of the first and second single-mode fibers are fused to end surfaces of the hollow core fiber. The waveguide includes an input optical waveguide, an inner surface waveguide having an evanescent field and an output optical waveguide. The two end surfaces of the input optical waveguide are connected with an end surface of the core of the first single-mode fiber and an end surface of the inner surface waveguide respectively. The two end surfaces of the output optical waveguide are connected with an end surface of the core of the second single-mode fiber and the other end surface of the inner surface waveguide respectively.

Abstract: A posture prediction method includes: acquiring an action area in the scene image by acquiring a scene image obtained by scanning a three-dimensional scene, acquiring an action label corresponding to the action area, the action label is configured to represent the action performed by the human body in the action area, acquiring posture data according to the action area and the action label, acquiring a human body posture model according to the posture data, and mapping the human body posture model into the three-dimensional scene according to the action area and the posture data.

Abstract: Provided are a fully homomorphic encryption method and device and a computer readable storage medium capable of enhancing efficiency of a homomorphic multiplication operation in a fully homomorphic encryption method. The method comprises: Step S1: generating a prime modulus qj=qj(?, L), according to an input security parameter ? and a number of encryption layers L, wherein qj mod n?1, n is an integer power of 2, j=0, 1, . . . , L?1, and q0<q1< . . . <qL-1; Step S2: generating a private key sk and a public key pk according to the prime modulus qj; Step S3: encrypting plaintext m according to the public key pk; and Step S4: performing a homomorphic operation on two ciphertexts associated with the same private key, the homomorphic operation includes a homomorphic addition operation FHE.Add(c?, c?) and a homomorphic multiplication operation FHE.Mul(c?, c?).

Abstract: A vibration signal-based smartwatch authentication method includes generating incremental vibration signals using a vibration motor in a smartwatch; performing frequency band-based hierarchical endpoint segmentation to obtain vibration signals at a plurality of frequency bands; extracting frequency-domain features for the vibration signals at the plurality of frequency bands; training a dynamic time warping model by taking the vibration signals at the plurality of frequency bands as a training data set, training a nearest neighbor model by taking the extracted frequency-domain features as training data; collecting to-be-authenticated vibration signals which are processed to serve as test data signals; discriminating similarities between the test data signals and corresponding training data signals through the dynamic time warping model, giving a classification result through the nearest neighbor model, performing weighted calculation on a discrimination result of the dynamic time warping model and a discrimin

Abstract: The present disclosure relates to a method and related system for spectrum optimization of an illumination light source. Spectrum optimization according to the present disclosure can be based on various optimization parameters, including but not limited to luminous efficacy, color rendering effect, luminous efficacy of radiation, mesopic efficacy of radiation, cirtopic efficacy of radiation, etc. The present method and system are capable of optimizing illumination performance of a light source in various aspects in an individual or integrated manner. Further, the present method and system are capable of accommodating different illumination purposes and conditions by combining and prioritizing different optimization parameters.

Abstract: For wireless communication method, a to-be-transmitting signal is divided into (n+1) packets using a key pre-agreed to by a transmitter and a receiver, where n is a positive integer. The to-be-transmitted signal comprising a regular signal and a tag signal, said tag signal forming an authentication signal. When the difference between received amplitude values of the regular signal and tag signal fail to meet a first pre-determined requirement, a first power parameter adjustment factor is determined for the n packets preceding an (n+1)th packet and a second power parameter adjustment factor is determined for the (n+1)th packet, as well as an energy-limited condition of the to-be-transmitted signal power. The transmitted power of the respective (n+1) packets is then adjusted according to the corresponding power parameter adjustment factor before the to-be-transmitted signal is transmitted.

Abstract: A wireless communication method and device include: a transmitting device dividing a to-be-transmitted signal into a plurality of packets by using a pre-agreed key; acquiring a preset equivocation threshold; according to the equivocation threshold, determining a power parameter adjustment factor for each of the packets; for each of the packets, performing power adjustment on a signal of the packet according to a power parameter adjustment factor of the packet; and transmitting the to-be-transmitted signal after power adjustment. After receiving the signal, the receiving device groups the signals according to the pre-agreed key, and calculates the power of each packet; determines a test statistic according to the power of each packet, and determines the test statistic whether the quantity is greater than or equal to a preset statistic threshold. If so, it determines that the signal is a tag signal, and if not, that it is a regular signal.

Abstract: Provided are a polymer having ultraviolet absorption functionality and preparation method thereof; specifically, three monomers having different ultraviolet absorption bands are used for copolymerization, achieving a significant expansion of the ultraviolet absorption range and achieving the effect of full-band ultraviolet shielding. The obtained polymer film has strong visible light transmittance, fluorescence, easy processing, excellent stability, and remarkable ultraviolet shielding performance, and can be broadly applied in such areas as aviation, construction, agriculture, and optical devices.

Abstract: A smart device input method based on facial vibration includes: collecting a facial vibration signal generated when a user performs voice input; extracting a Mel-frequency cepstral coefficient from the facial vibration signal; and taking the Mel-frequency cepstral coefficient as an observation sequence to obtain text input corresponding to the facial vibration signal by using a trained hidden Markov model. The facial vibration signal is collected by a vibration sensor arranged on glasses. The vibration signal is processed by: amplifying the collected facial vibration signal; transmitting the amplified facial vibration signal to the smart device via a wireless module; and intercepting a section from the received facial vibration signal as an effective portion and extracting the Mel-frequency cepstral coefficient from the effective portion by the smart device.

Abstract: A linear asymmetric method for examining branch-outage-type steady-state security of AC power networks is provided. Two linear expressions of bus injection active and reactive powers in terms of translation voltages and voltage angles of all buses are established. Then a linear asymmetric matrix-equation model for the steady state of the network is built considering the reference bus number. Manipulating this model produces the matrix expression of branch-not-outage-type translation voltages and voltage angles of non-reference buses and the bus impedance matrix with the reference bus discarded. The branch-outage-type translation-voltage increments and voltage-angle increments of non-reference buses are then obtained by the bus impedance matrix and the outage branch using the calculation formula of ordinary inverse of a modified matrix. The examination of the steady-state security of the network is achieved using these increments.

Abstract: A symmetric method for obtaining network-power-loss components induced by sources and loads at individual buses in AC power networks is invented. Two linear expressions of bus injection active and reactive powers in terms of translation voltages and voltage angles of all buses are established at first. Then a linear symmetric matrix-equation model for the steady state of the network is built. Manipulating this model by Moore-Penrose pseudoinverse produces a linear symmetric matrix expression of translation voltages and voltage angles of all buses in terms of bus injection powers. Expressing the network power loss in terms of source's and load's powers by this matrix expression, a symmetric algebraic calculation formula for obtaining the network-power-loss components is produced after manipulating by Shapley value theorem, by which the obtaining of network-power-loss components are achieved. The set of network-power-loss components provides a new efficient tool for economic operation of AC power networks.

Abstract: A symmetric method for obtaining bus-translation-voltage components induced by sources and loads at individual buses in AC power networks is invented. Two linear expressions of bus injection active and reactive powers in terms of translation voltages and voltage angles of all buses are established according to branch admittances and bus injection powers of sources and loads. Then a linear symmetric matrix-equation model for the steady state of the network is built. Manipulating this model by Moore-Penrose pseudoinverse produces a linear symmetric matrix expression of translation voltages and voltage angles of all buses in terms of bus injection powers. Finally a linear symmetric algebraic calculation formula for obtaining the bus-translation-voltage components is extracted from this matrix expression to achieve obtaining of the bus-translation-voltage components.

Abstract: A fruit and vegetable picking method and device based on machine vision and storage medium that includes: acquiring fruit image of fruit or vegetable to be picked currently, calling pre-trained neural network model to identify fruit image, and determining type of fruit or vegetable; acquiring type of fruit or vegetable, and determining cuttable area on stalk of fruit or vegetable according to type of fruit or vegetable, locating cutting point; controlling end picking apparatus to cut off stalk of fruit or vegetable, according to cutting point being determined. By using pre-trained neural network model to detect fruit and cut stalk for picking, one device may be able to pick multiple fruits and vegetables, have high versatility and picking accuracy, avoid hurting pulp, and have improved harvest efficiency and quality of fruits and vegetables picked.

Abstract: The present application is applicable to the fiber optics field and provides a hybrid fiber coupler including a lead-in single mode fiber, a coreless fiber, a hollow glass tube and a lead-out single mode fiber fusion-spliced sequentially. Both the lead-in single mode fiber and the lead-out single mode fiber include cores and claddings. Cores of the lead-in single mode fiber and the lead-out single mode fiber are not in the same horizontal direction. A curved waveguide is inscribed inside the coreless fiber and the hollow glass tube and cores of the lead-in single mode fiber and the lead-out single mode fiber are connected with said curved waveguide. The hollow glass tube has a micro-channel at either end thereof, and the two micro-channels form a microfluidic channel with the center of the hollow glass tube for allowing the analytical liquid to access the hollow glass tube.

Abstract: A system and a method for fabrication of bulk nanocrystal alloys is provided. The method may include subjecting powders of at least one material to an ultrasonic vibration at a first amplitude. The method may also include heating the powders in response to the ultrasonic vibration at a first temperature elevating rate corresponding to the first amplitude, and treating the powders in a temperature range corresponding to the first temperature elevating rate. The method may further include obtaining a bulk material composed of a plurality of crystal grains, the plurality of crystal grains having an average linear dimension equal to or larger than 10 nm. The method may further include obtaining a bulk material with amorphous structure with sufficient temperature cooling rate.