Abstract: This invention relates to a self-excited oscillation suppression device and method for the power amplifying circuit, belonging to the field of electronic technology. Said power amplifying circuit includes a FET and a feedback loop. Said device includes: a first compensation circuit which is connected between a drain and a gate of the FET and a second compensation circuit which is connected in parallel with a feedback resistor of said feedback loop. It can solve self-excited oscillation caused by deep negative feedback in the existing power amplifying circuit. The first compensation circuit can shift the open-loop gain curve forward as a whole, and the second compensation circuit can speed up the closure of the feedback gain curve and the open-loop gain curve so that the two curves will close up before the self-excited oscillation; the self-excited oscillation will be suppressed, and the stability of the power amplifying circuit will be improved.

Abstract: The present invention provides a fluorine-containing liquid crystal polymer of Formula (1). The present invention also discloses a fluorine-containing liquid crystal elastomer, which comprises a copolymer of a fluorine-containing liquid crystal polymer of Formula (1) with a near-infrared dye of Formula (2). The fluorine-containing liquid crystal elastomer of the present invention shrinks due to the photothermal conversion effect of the material under the irradiation of near-infrared light, and thus is widely applicable to the field of actuators. The fluorine-containing liquid crystal polymer of the present invention introduces fluorine-containing segments into the cross-linked network of the liquid crystal polymer, to improve the mechanical performance of the material, and greatly extend the service time of light-controlled actuators.

Abstract: The present invention relates to an oligomer-based organic battery materials, cathode active material, cathode and secondary battery comprising such material, and a process for preparing such materials.

Abstract: An embodiment of the present invention discloses a repair system for a planetary exploration parachute. The repair system includes a folding piece and a fuse, the fuse is provided in the folding piece, a sensing signal for reflecting an impact force of dust is received by the fuse, fusing is generated in the fuse when the sensing signal is greater than a preset threshold, and the folding piece is changed from a folded state to an unfolded state after the fusing is generated in the fuse, so as to automatically repair a damaged part of the parachute.

Abstract: The present invention discloses a method for the design of complex-valued channel equalizer of digital communication systems, including: constructing a channel equalizer by using a complex-valued neural network; collecting the output signal y(n)=[y(n), y(n?1), . . . , y(n?m+1)]T of the nonlinear channel of the underlying digital communication system as the input of complex-valued neural network and s(n??) as the desired output, and taking the mean squared error as the loss function for the training of complex-valued neural network, which is optimized by the proposed adaptive complex-valued L-BFGS algorithm, and finally using it to implement the design of channel equalizer for digital communication systems. The present invention proposes the use of a multi-layer feedforward complex-valued neural network to construct complex-valued channel equalizer.

Abstract: The invention provides a wide-aperture spherical primary mirror off-axis afocal optical system, including a primary mirror, a secondary mirror and an aberration compensation mirror group. The primary mirror is a spherical reflector, the secondary mirror are higher-order aspherical reflectors. The primary mirror and the secondary mirror form an off-axis two-mirror system to compress the beam aperture. The aberration compensation mirror group is a coaxial reflective system that is used off-axis. The aberration compensation mirror group has focal power to produce compensation aberrations. The incident beam passes through and is reflected by the primary mirror and secondary mirror sequentially and enters the aberration compensation mirror group thereafter.

Abstract: A high-grafting density cyclic comb shaped polymer and its preparation method therefor. The method comprises the following steps: 1) synthesizing linear poly(pentafluorophenyl 4-vinylbenzoate) (l-PPF4VB4.0k); 2) performing photo-induced cyclization on the linear polymer to prepare the cyclic polymer (c-PPF4VB4.0k); 3) performing post modification on the cyclic polymer c-PPF4VB4.0k by using small molecules to prepare a functionalized cyclic polymer (c-P1); 4) then performing polymer post modification on the cyclic polymer (c-P1) by using an efficient click reaction to construct the high-grafting density cyclic comb shaped polymer (c-P1-g-PS); and 5) directly performing polymer post modification on the cyclic polymer c-PPF4VB4.0k by using macromolecules to construct a high-grafting density cyclic comb shaped polymer (c-PPF4VB4.0k-g-PEG), the obtained cyclic comb shaped polymer still remaining the characteristic of a narrow molecular weight distribution.

Abstract: The invention provides a visible light communication system with adaptive dimming and a modulation and demodulation method. The system includes: a source; an adaptive M-PAM modulator, separately modulating a signal transmitted by the signal source into a first and a second electrical signal; and a dual-path pulse generator, alternately generating a first and a second pulse control signal, where the first and the second pulse control signal are both periodic signals, where when a remaining operating duration of a high level of the first pulse control signal equals to a time of a rising edge of the second pulse control signal, the second pulse control signal starts to be generated, and when a remaining operating duration of a high level of the second pulse control signal is equal to a time of a rising edge of the first pulse control signal, the first pulse control signal starts to be generated.

Abstract: The present invention discloses a path planning method, including the following steps: establishing an empirical map and a corresponding episodic cognitive map using a RatSLAM algorithm based on an episodic memory model; extracting a road edge in a historical memory image with a Canny operator; performing conversion to a world coordinate system from a pixel coordinate system based on the road edge, and preliminarily judging connectivity according to slope of the road edge; continuously injecting energy into the potential path detection network according to continuous observation of a potential path, so as to further judge the road connectivity; fusing the detected potential path and the original episodic cognitive map, and correspondingly updating the empirical map; and planning a path based on the updated episodic cognitive map. The potential safe path in an environment may be detected, and a better path may be planned based on the updated episodic memory model.

Abstract: The present invention relates to a surface-modified aramid fiber and a method for preparing the same. The method includes the following steps: modifying an aramid fiber having amino groups and carboxyl groups on the surface with siloxane ?-glycidoxypropyltrimethoxysilane to obtain a silicon methoxylated aramid fiber; reacting same with a cerium oxide coated with polydopamine modified chaotic boron nitride to obtain a surface-modified aramid fiber. The cerium oxide coated with polydopamine modified chaotic boron nitride has high ultraviolet absorption, and has extremely low catalytic activity, avoiding the damage to a fiber structure by photocatalysis during radiation, being an effective, safe and highly-efficient ultraviolet absorber. The surface-modified aramid fiber provided in the present invention has an ultraviolet-resistant function, high surface activity, good thermal performance, and better mechanical performance, providing excellent overall performance, and having higher utilization value.

Abstract: A preparation method for a piezoelectric fiber is provided including a piezoelectric functional layer and an insulating layer coated on the piezoelectric functional layer. The piezoelectric functional layer includes a piezoelectric composite layer of a spiral winding structure, and the piezoelectric composite layer includes a first piezoelectric layer, a conductive layer and a second piezoelectric layer that are sequentially stacked. The preparation method includes taking one end of the piezoelectric composite layer as a winding axis, winding the piezoelectric composite layer in a direction perpendicular to the winding axis to form the piezoelectric functional layer, wherein turns of winding the piezoelectric composite layer are greater than 5, coating the piezoelectric functional layer with the insulating layer, and vacuum heating to consolidate, to prepare a preform rod.

Abstract: The present invention relates to the application of lithium 4-methoxyaniline in catalysis of the hydroboration reaction of an imine and a borane. A catalyst, a borane and an imine are successively stirred and mixed until uniform, reacted for 1 to 2 hours, and then exposed to air so as to stop the reaction, and the reaction liquid is subjected to decompression to remove a solvent therein, so as to obtain a borate with different substituents. The lithium 4-methoxyaniline disclosed in the present invention can catalyze the hydroboration reaction of an imine and a borane in a high activity manner at room temperature, wherein the amount of the catalyst is merely 4-5 mol % of the molar amount of the imine, and the yield of the reaction can reach 90% or more. The yield of a borate with different substituents can reach 99% with mild reaction conditions under an optimized condition.

Abstract: Disclosed is an application of an ionic iron (III) complex as a catalyst in preparation of a benzylamine compound, that is, an ionic iron (III) complex having a molecular formula of [(RNCHCHNR)CH][FeBr4] (R is tert-butyl) and containing 1,3-di-tert-butyl imidazolium cation is used as a catalyst, di-tert-butyl peroxide is used as an oxidizing agent, and a benzylamine compound is synthesized by oxidation reaction of a toluene/ethylbenzene compound with an aromatic amine. The present invention has a wide application range, and is applicable not only to a toluene compound containing a benzylic primary carbon-hydrogen bond but also to an ethylbenzene compound containing a benzyl secondary carbon-hydrogen bond. This is the first example of the preparation of a benzylamine compound by oxidation reaction of a toluene/ethylbenzene compound and an aromatic amine by an iron-based catalyst.

Abstract: Disclosed are a trifluoromethyl alkenylphosphonate derivative and preparation method therefor. The preparation method comprises the following steps: dissolving an acetylene derivative, an iodine compound, and a phosphorus reagent in a solvent for reaction at the temperature from the room temperature to 100° C. to obtain the trifluoromethyl alkenylphosphonate derivative. In the present invention, the acetylene derivative is used as a starting material, and the raw materials are easily available and diversified; products obtained by using the method of the present invention have various types and can be directly used and also used for other further reactions; moreover, the method disclosed in the present invention has the advantages of short steps, mild reaction conditions, simple reaction operation and post-treatment processes, and high yield, and is suitable for large-scale production.

Abstract: The invention relates to a fault diagnosis method for a rolling bearing under variable working conditions. Based on a convolutional neural network, a transfer learning algorithm is combined to handle the problem of the reduced universality of deep learning models. Data acquired under different working conditions is segmented to obtain samples. The samples are preprocessed by using FFT. Low-level features of the samples are extracted by using improved ResNet-50, and a multi-scale feature extractor analyzes the low-level features to obtain high-level features as inputs of a classifier. In a training process, high-level features of training samples and test samples are extracted, and a conditional distribution distance between them is calculated as a part of a target function for backpropagation to implement intra-class adaptation, thereby reducing the impact of domain shift, to enable a deep learning model to better carry out fault diagnosis tasks.

Abstract: The present invention relates to an immunomodulating peptide comprising an amino acid sequence as shown in SEQ ID NO:1. The present invention also discloses use of the immunomodulating peptide in the preparation of a drug or skin care product for promoting skin wound healing. The present invention provides a new immunomodulating peptide and use thereof, and discloses the mechanism of action of the immunomodulating peptide in promoting wound healing. The immunomodulating peptide is useful as a wounding healing polypeptide template.

Abstract: A method for detecting a surface welding quality of friction stir welding includes: acquiring a continuous surface depth image of a welding seam; intercepting a surface depth image segment of the welding seam with a proper step size, and dividing the intercepted surface depth image segments of the welding seam into a front reference region, a thinned region and a rear reference region; judging whether flatness of the front reference region is less than a threshold, and if yes, taking a height of the front reference region at this point as a latest reference height; if no, judging whether the flatness of the rear reference region is less than the threshold, and if yes, taking a height of the rear reference region at this point as the latest reference height; if no, taking the reference height of previous depth image segment as the latest reference height; and calculating a difference.

Abstract: The present invention relates to a method and system for allocating a dedicated protected spectrum based on crosstalk awareness, including calculation, core selection, a modulation format, and spectrum allocation. First, working paths are first established: selecting a modulation format; determining a maximum allowable crosstalk value, classifying cores, calculating inter-core crosstalk values of all available spectrum blocks, and selecting a spectrum block with the smallest crosstalk value for allocation; and then dedicated protection paths are established: selecting a modulation format; determining a maximum allowable crosstalk value, classifying cores, calculating inter-core crosstalk values of all available spectrum blocks, and selecting a spectrum block with the smallest crosstalk value for allocation.

Abstract: Disclosed is a method for preparing a benzyl amine compound, i.e., synthesizing a benzyl amine compound by means of an oxidation reaction between a methylbenzene/ethylbenzene compound and arylamine by using an ionic iron (III) complex containing 1,3-di-tert-butylimidazolium cation and having a molecular formula of [(RNCHCHNR)CH][FeBr4] (R being tert-butyl) and di-t-butyl peroxide as an oxidant. The present invention is not only applicable to a methylbenzene compound containing a benzylic primary carbon-hydrogen bond but also applicable to an ethylbenzene compound containing a benzylic secondary carbon-hydrogen bond, and therefore is widely applicable. This is the first case where the preparation of a benzyl amine compound by means of an oxidation reaction between a methylbenzene/ethylbenzene compound and arylamine is implemented by an iron catalyst.

Abstract: The present invention discloses a fluorescent chromic material having a chemical formula of [PPy3Cu2I2]n, wherein PPy3 is tripyridylphosphine. The present invention also provides a method for preparing the fluorescent chromic material, and the use of the fluorescent chromic material in the detection of dichloromethane vapor. The fluorescent chromic material of the present invention has simple synthesis steps, high yield, and capability of large production; and can be used as a fluorescent probe for detecting dichloromethane vapor. It has the advantages of simple operation, high selectivity, high sensitivity, good cycle performance and good stability.