232results about How to "Increased Design Freedom" patented technology

The invention discloses preparation of a titanium-based composite material continuous core net structure wire material for fuse wire additive manufacturing. Comprising the following steps: taking a titanium belt as an external titanium shell, and taking fine net-shaped titanium-based composite material composite powder as filling powder; and the titanium shell and the filling powder are rolled in a sealed mode, drawing and diameter reducing are conducted, a continuous core net structure wire is formed, and then the in-situ synthesis reinforced titanium-based composite material is prepared through a fuse wire additive manufacturing method. According to the method, the in-situ synthesis reaction of a reinforcement body of the continuous core net structure wire in the melting process is fully played, matrix grains are refined, the organization structure and the size and distribution of the reinforcement body are accurately regulated and controlled, the comprehensive mechanical property of the additive manufacturing titanium-based composite material can be improved, and the method has the advantages of being high in design freedom degree, high in material utilization rate and the like; and a new method is provided for integrated preparation of the difficult-to-deform titanium-based composite material complex component.

The invention discloses a steer-by-wire system self-adaptive steering angle tracking strategy based on a high-order all-drive theory, which comprises the following steps of: 1, establishing a kinetic model of a steer-by-wire system according to the steer-by-wire system of a passenger vehicle, and determining a state variable and a control variable; 2, designing an extended disturbance observer according to the kinetic model established in the step 1, and observing the internal and external uncertainty and disturbance of the system, and compensating the uncertainty and disturbance to a controller; 3, converting the steering-by-wire system dynamics model in the step 1 into an all-wheel-drive system model, and designing a self-adaptive high-order all-wheel-drive controller; and 4, verifying the stability of the high-order all-wheel-drive controller designed in the step 3 according to a Lyapunov stability method. According to the method, uncertainty interferences inside and outside the system are considered in the built steer-by-wire system model, the interferences are lumped, the extended disturbance observer is used for observation and compensation to the controller, and the accuracy and robustness of the control system are improved.

The invention relates to the technical field of optical communication packaging, in particular to an optical interconnection packaging method. A two-dimensional stacking mode is adopted for the optical fiber waveguide and the single-core optical fiber array to be packaged, the end faces of the optical fiber waveguide and the single-core optical fiber array face the same direction, the section of a port uniformly faces the vertical upper portion, and the position of the port can be directly positioned in an image through a common objective lens imaging system. A complicated high-precision side fiber core identification system is avoided; according to the identified positions of the two ports, designing and using a two-photon 3D printing technology to process an optical polymer connection waveguide between the ports; the whole packaging process is relatively simple to operate, and the cost is saved; moreover, the optical interconnection packaging method provided by the invention is wider in application range.

The invention provides an encryption method based on a metasurface, and belongs to the technical field of optical encryption. A to-be-encrypted pattern is manufactured into a mask after being electronically encrypted, under the action of a light field, the encrypted pattern is coded to a super-structure surface through the mask, the super-structure surface with the linear operation mapping capacity is designed through a reverse design method, and the encrypted pattern is modulated by the super-structure surface and then restored into an original pattern. The metasurface is used for executing the function of decrypting the matrix, the advantages of high integration level, high modulation capability and high design freedom degree of the metasurface are fully utilized, arrangement can be carried out at different spatial positions, encryption combination forms are increased through coupling of the wavelength of a light field and spatial information of the metasurface, the security of the system is improved, and the method is suitable for being applied to the field of encryption. And the information capacity in the encryption process can be improved, and complicated keys do not need to be stored and transmitted.

The embodiment of the invention provides an optical module and near-to-eye display equipment. The optical module is used for XR optical equipment and comprises a cemented prism and a lens which are adjacent and arranged at an interval. The cemented prism comprises a first prism, a polarization reflection element and a second prism which are arranged in sequence, the lens is located on the side, away from the first prism, of the second prism, and a phase retarder is arranged between the lens and the second prism; the lens comprises a fifth surface and a sixth surface, the sixth surface deviates from the cemented prism, and the sixth surface is a partial reflection surface; the cemented prism and the lens comprise at least two curved surfaces; the optical module meets the condition that EFL24 / EFL56 is more than or equal to 7.4 and less than or equal to 9.2; eFL24 is the effective focal length of the cemented prism, and EFL56 is the effective focal length of light which enters from the fifth surface, is reflected by the sixth surface and then exits from the fifth surface.

The invention discloses a multi-agent system quantization consistency privacy protection method based on general state decomposition, which comprises the following steps of: designing a privacy protection mechanism based on general state decomposition, and performing state decomposition and weight setting on each node according to own demand and capability, reconstructing a false initial state for transmission communication; establishing a quantization consistency control model of the multi-agent system: considering a system formed by N nodes, representing a relationship among dynamic behaviors of each node by using a difference equation based on graph theory knowledge, introducing an encoding and decoding quantization mechanism under the assumption of quantization transmission, and giving specific settings of an encoder and a decoder; an eavesdropping attack model is introduced, wherein eavesdropping of internal curious nodes and external eavesdroppers on states in the network is considered; performing correctness analysis on a system consistency convergence result: based on knowledge of a graph theory, a matrix theory and a stability theory, analyzing a dynamic behavior of an intelligent agent to obtain a final convergence consistency result; according to the method, the privacy of a multi-agent system is analyzed, and privacy analysis under different eavesdropping attacks is given by designing a quantitative index of privacy protection based on the non-distinguishability of initial state change. According to the invention, the designed control protocol is simple and easy to implement, communication resources can be saved, correct consistent convergence is ensured, and more comprehensive privacy protection is provided.

The invention discloses an electronic device heat dissipation structure level set topological optimization method and system based on a physical information neural network, and the method comprises the steps: describing a heat exchange behavior between a radiator and a heat source through a heat conduction model, and determining a corresponding boundary condition through a specific heat conduction physical phenomenon; a topological optimization numerical model suitable for a heat dissipation structure is provided according to a level set method, a heat transfer control equation based on an interpolation material is obtained through methods such as interpolation of thermophysical properties of the material through a characteristic function of a level set, and target functions such as the minimum average temperature or the minimum average temperature variance are set, so that the heat transfer control equation of the heat dissipation structure is obtained. And deriving an adjoint equation and sensitivity of the heat transfer equation by adopting a continuous adjoint method, solving the heat transfer equation, the adjoint equation and the reaction diffusion level set equation through a physical information neural network, and further updating a level set function. By adopting the heat dissipation structure optimization method provided by the invention, the design freedom degree is higher, and the temperature of the heat dissipation area can be effectively reduced.

The invention belongs to the field of solid-state lithium metal batteries, and particularly relates to a component gradient solid-state electrolyte and a preparation method thereof, and the component gradient solid-state electrolyte comprises a poly (ethylene oxide) (PEO)-based electrolyte for stabilizing a lithium metal negative electrode and a poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)-based solid-state electrolyte for stabilizing a high-voltage positive electrode. The preparation method is a multi-material 3D printing technology based on a mixed printing nozzle, and the solid electrolyte film with component proportion gradient change is realized by dynamically changing the mixing proportion of two electrolytes. The obtained polymer-based component gradient electrolyte can be compatible with a lithium metal negative electrode and a high-voltage positive electrode material at the same time, and is suitable for a high-energy-density solid-state lithium metal battery. The preparation method is simple, low in cost and easy for large-scale production.

The invention provides an ultra-wideband amplifier based on multi-inductor coupling. The ultra-wideband amplifier comprises a multi-inductor high-order coupling network and a multi-stage cascade network, the multi-inductor high-order coupling network comprises a multi-inductor high-order input matching network and a multi-inductor high-order inter-stage matching network; the multi-stage cascade network comprises a cascode amplification module, a common-source amplification module and a voltage bias module; the design freedom degree of the multi-order matching network is improved, meanwhile, gain planarization, a low noise coefficient and good matching are achieved, and the chip area is reduced; according to the invention, conjugate matching to 50 ohms can be realized in a very wide bandwidth, and broadband matching is realized; the quality factor of the grid inductor is improved, the loss caused by series resonant cavities is improved, and the noise coefficient is reduced; according to the invention, the bandwidth can be further improved, and a plurality of networks act together to present the final ultra-wideband; according to the invention, the input signal source admittance is changed, so that the source admittance is close to the optimal noise impedance, and the impedance required by conjugate matching and the optimal noise impedance are realized.

The invention discloses a low-noise amplifier structure adopting multi-inductor coupling and current multiplexing, which comprises a multi-inductor coupling network and a full-nmos current multiplexing technology network, the multi-inductor coupling network is connected with the full-nmos current multiplexing technology network, the full-nmos current multiplexing technology network is used for enabling the same current to flow through a multi-stage amplifier, and the multi-stage amplifier is connected with the full-nmos current multiplexing technology network. The multi-stage amplifiers share the same power supply voltage; and the multi-inductance coupling network is used for realizing broadband maximum power transmission matching and noise coefficient matching at an input node so as to realize high power transmission and low noise coefficient. According to the invention, broadband input matching and noise matching can be realized at the same time. The invention can be widely applied to the field of radio frequency receiver front ends.

A three-period minimal curved surface primary surface heat exchanger based on proportion hybridization belongs to the technical field of heat exchangers, aims to solve the problem of improving the heat exchange effect of a primary heat exchanger, and is technically characterized by comprising a hybridized three-period minimal curved surface core body which is formed by a SchwartzDiamond type three-period minimal curved surface and a Gyandroid type three-period minimal curved surface based on proportion hybridization, a cold fluid channel opening and a hot fluid channel opening are formed in the surface of the core body, a cold fluid channel and a hot fluid channel are formed in the core body, the heat exchanger has the advantages that the power-to-weight ratio and the heat exchange efficiency of heat transfer performance characterization of the heat exchanger are remarkably improved, and the heat exchanger can be used for light-weight efficient heat transfer in a heat management system of an aviation aircraft.

The invention belongs to the field of material and electronic device manufacturing, and discloses a capacitive micromachined ultrasonic transducer based on 3D printing and a preparation method thereof.The CMUTs comprise an upper electrode, an upper insulating layer, a vibrating membrane, a supporting column layer, a silicon substrate and a lower electrode which are sequentially connected from top to bottom, and a cavity is formed among the vibrating membrane, the lower insulating layer and a supporting column of the supporting column layer; the method comprises the following steps: printing a pillar layer array on the front surface of a silicon substrate with a functionalized surface by utilizing a nano silicon dioxide composite material and adopting a photocuring 3D printing method; then curing and heat treatment are carried out to obtain a second device; bonding a vibrating diaphragm; printing an insulating layer on the front surface of the vibrating diaphragm; carrying out curing and heat treatment; printing an upper electrode; removing the silicon dioxide on the back surface of the silicon substrate through a wet etching process; printing a lower electrode on the back of the silicon substrate; and removing the photoresist. According to the invention, the consumption of required equipment and materials is reduced, and the production cost is reduced.

The invention discloses a periodically broken grating surface emitting terahertz quantum cascade laser and an optimization method. The periodic broken structure is introduced into the electrode layer, the potential periodicity of the periodic broken structure ensures the formation of distributed feedback, resonance and frequency selection in the laser can be realized, and meanwhile, due to the non-periodic characteristic of the periodic broken structure locally, the resonance mode of the periodic broken structure is between a symmetric mode and an anti-symmetric mode, so that the frequency selection efficiency of the laser is improved. Therefore, the radiation efficiency and the power of the laser can be effectively improved. Meanwhile, grating parameters are optimized through the genetic algorithm, the difficulty and time cost of forward design of the grating structure by analyzing the mode field are reduced, and the method has high design freedom degree and flexibility. The terahertz quantum cascade laser grating structure designed by the invention has high radiation efficiency and can realize high-power output.

The invention provides a large floating body connecting system and a using method thereof. The large floating body connecting system is used for connecting a first large floating body and a second large floating body which are adjacent on the sea and comprises a plurality of prestress tensioning devices and a plurality of strands of limiting mooring ropes, the prestress tensioning devices are connected with upper structures of the large floating bodies, and the limiting mooring ropes are connected with lower floating boxes of the large floating bodies. Each pre-stress tensioning device comprises a pre-stress cable and a pre-tensioning cable which are arranged side by side; the plurality of prestress tensioning devices are configured to keep fit connection between the two large floating bodies under normal sea conditions; and when the two large floating bodies cannot maintain attached connection under the severe sea condition, the tensioning state of the prestressed cable and the pre-tensioning cable is relieved, and non-attached connection between the first large floating body and the second large floating body is achieved. The method is suitable for mutual connection of a plurality of deep and far sea large floating bodies, and a reliable solution is provided for floating body development and design of ship and ocean engineering and ocean energy development.

The invention relates to an additive manufacturing method of a continuous fiber reinforced composite material, belongs to the technical field of additive manufacturing, and solves the problems that an existing additive manufacturing technology is not suitable for continuous fiber reinforced metal matrix and ceramic matrix composite materials, and the process quality of additive manufacturing of a continuous fiber reinforced resin matrix composite material is poor. An additive manufacturing method of a continuous fiber reinforced composite material comprises the steps that S1, a three-dimensional model of a laminated composite material product is established, slicing treatment is carried out, and each layer of two-dimensional fiber fabric is contained in a corresponding slice; s2, prefabricating a two-dimensional fiber fabric in a layered manner; and S3, additive manufacturing of the laminated composite material product is conducted through a 3D printing forming method. According to the method, rapid additive manufacturing of continuous fiber reinforced ceramic-based, metal-based and resin-based composite materials is achieved, fiber and matrix infiltration in the obtained product is good, the interface bonding strength is high, and compared with a continuous fiber reinforced composite material obtained through an existing method, the continuous fiber reinforced composite material has better process quality and performance.

The invention discloses an explicit-implicit hybrid topological optimization method for multi-material structure design. The method comprises the steps that firstly, design variables including component variables and material selection density variables are confirmed; secondly, building a unit density function based on the material agent model and the material selection model; then, on the basis of the unit density function, an objective function is constructed, constraint conditions are set, an overall stiffness matrix under the multi-material structure is established, and finite element analysis is carried out; respectively carrying out sensitivity analysis on the MMC variable and the SIMP variable, and updating the design variable; and finally determining convergence. According to the method, an explicit movable deformable assembly method and an implicit solid isotropic material punishment method are effectively combined, a group of geometric parameters are used for describing the structure topology, design variables are reduced, and a larger design freedom degree is provided for material layout in the structure.

The present invention discloses a construction method of a heat exchanger based on a radially heterogeneous graded three-period minimal surface structure, comprising: dividing the space in the heat exchanger into cold fluid channels and hot fluid channels that intersect but do not interpenetrate each other through selected three-period minimal surface cells, obtaining the rectangular coordinate system equations of the three-period minimal surface cells at the same time, and hybridizing and connecting the selected different three-period minimal surface cells to obtain a newly formed hybrid function; adjusting the overall structure of the cells according to the newly formed hybrid function, and performing coordinate transformation on the rectangular coordinate system equation to obtain a target function; adjusting the number of periods of the cells in each direction in the heat exchange core based on the target function, and adding a shell outside the core to obtain a newly constructed heat exchanger. The present invention realizes a multi-stage TPMS structural design with lower stress concentration, and effectively solves the problem of reduced compactness caused by the increase in the size of the minimal surface structure, thereby improving heat exchange performance.

The invention relates to a continuous fiber reinforced metal-based composite material and an additive manufacturing method thereof, belongs to the technical field of additive manufacturing, and solves the problems that in the prior art, the continuous fiber reinforced metal-based composite material is difficult to realize 3D printing, and the integrity and consistency of fibers and / or poor infiltration of the fibers and a matrix are / is solved. An additive manufacturing method of a continuous fiber reinforced metal matrix composite comprises the steps that S1, a three-dimensional model of a laminated composite product is established, slicing treatment is conducted, and each layer of two-dimensional fiber fabric is contained in the corresponding slice; s2, prefabricating a two-dimensional fiber fabric in a layered manner; and S3, additive manufacturing of the laminated composite material product is conducted through a selective laser melting forming method. Rapid additive manufacturing of the continuous fiber reinforced metal-based composite material is achieved, fibers in the obtained continuous fiber reinforced metal-based composite material and a product of the continuous fiber reinforced metal-based composite material have good integrity, consistency and stability, infiltration of the fibers and a matrix is good, and the interface bonding strength is high.

The invention provides a projection device which comprises a light source module, a display panel, a free-form surface reflector and a projection lens. The light source module comprises a light source, a first Fresnel lens and a second Fresnel lens. The first Fresnel lens and the second Fresnel lens are parallel to each other and are located between the light source and the display panel. The display panel is arranged between the light source module and the free-form surface reflector. The projection lens is used for transmitting the image light beam out of the projection device, and the direction of the optical axis of the projection lens is different from the normal direction of the first Fresnel lens. The projection device provided by the invention can improve the problem of projection picture distortion or picture edge resolution reduction.

The invention discloses a reflection type polarization conversion antenna with an adjustable stop band, which works in an X wave band and is composed of a dielectric substrate, a metal resonance structure layer arranged on one side of the dielectric substrate and a metal reflection layer arranged on the other side of the dielectric substrate, and the metal resonance structure layer comprises two groups of mutually nested symmetrical split circular ring resonance units. Through the technical means of translation, parameter adjustment and the like, the two groups of resonance units generate symmetry difference, so that different resonance units generate mutually counteracted surface current responses at a specific frequency, and a stop band for polarization conversion suppression is formed in a continuous working frequency band; the position and suppression intensity of the stop band can be controlled by adjusting the structural parameters of each resonance unit. While broadband high-efficiency polarization conversion is realized, a tunable narrowband polarization conversion zero point is introduced, and the tunable narrowband polarization conversion zero point has the advantages of simple structure, high regulation degree of freedom and good incident angle stability, and is suitable for communication, radar and signal monitoring systems of millimeter wave and microwave frequency bands.

The invention relates to the technical field of aircraft system fault detection, in particular to an aircraft system fault detection method based on an unknown input observer. According to the method, joint estimation of the state variable and the fault signal of the nonlinear aircraft system can be realized, and the influence of external disturbance on the estimation performance is effectively reduced. According to the method, the defects of an existing fault detection method based on residual signals can be overcome, the fault occurrence time can be provided, the estimated value of the fault amplitude can also be provided, the fault can be further processed in the later period, and the method has wider and profound theoretical significance and practical application value; estimated values of state variables and fault signals of the system can be provided at the same time, faults can be detected in time, and a certain foundation can be laid for monitoring dynamic behaviors of the system in real time and completing specific control tasks.

The invention provides a method for photocuring 3D printing of a high-temperature-resistant mold, and the method comprises the following steps: synthesizing high-temperature-resistant photocuring 3D printing resin which comprises the following components in percentage by weight: 50-80% of ethoxylated bisphenol A diacrylate, 15-35% of ethoxylated trimethylolpropane triacrylate, 5-10% of 2, 4, 6-trimethyl-1, 3-pentanediol monoisobutyrate, 5-10% of 2, 4, 6-trimethyl-1, 3-pentanediol monoisobutyrate, 5-10% of 2, 4, 6-trimethyl-1, 3-pentanediol monoisobutyrate, 5 the component A comprises the following components in percentage by weight: 3-10% of 2, 3, 6-trimethylbenzoyl-diphenyl phosphine oxide, 1-5% of filler and 0-2% of auxiliaries; a mold model is constructed through three-dimensional modeling software, and the mold model structurally comprises a conformal cooling water pipeline; slicing processing is conducted on the mold modeling model through slicing software, printing parameters are set, and a slicing file is generated; and the generated slice file is guided into photocuring 3D printing equipment, the high-temperature-resistant photocuring 3D printing resin serves as a 3D printing material, and a high-temperature-resistant mold is formed through the photocuring 3D printing technology. According to the method for photocuring 3D printing of the high-temperature-resistant mold, the high-temperature resistance and the compression resistance of the photocuring 3D printing molding high-temperature-resistant mold can be effectively improved.

The utility model relates to the technical field of elevator call-out, and discloses an elevator call-out device which comprises a panel and an assembly hole, a circuit board is fixedly installed inside the panel, a first LED lamp bead is fixedly installed at the top end of the front end of the panel, and a second LED lamp bead is arranged at the bottom end of the first LED lamp bead. The elevator call-out device is provided with the panel and other parts; a traditional LED segment code display module is replaced with an LED and lampshade surface paste, and the LED segment code display module has the advantages of being low in material cost, free in shape and size, diversified in display content, light and thin in design, simplified in assembly, low in maintenance cost, optimized in uniformity, high in contrast ratio, diversified in color, reliable and expansible. The LED segment code display module can exceed a traditional segment code module in the aspects of cost, design freedom degree and function expansibility, is particularly suitable for product schemes pursuing differentiation and high cost performance, and solves the problem of improvement of the traditional LED segment code display module in the aspects of cost, design freedom degree and function expansibility.

The present invention discloses a parking integrated brake caliper. It comprises a caliper body, a piston arranged in a cylinder hole of the caliper body, and a parking mechanism, wherein the parking mechanism comprises a fixed disk with a through hole in the center and a movable disk with an axis; the fixed disk is fixed at the bottom of the cylinder hole of the caliper body, a boss is arranged on the end face, the axis of the movable disk passes through the center hole of the fixed disk, the end face of the movable disk is provided with a periodically changing continuous curved surface meshing with the fixed disk boss, and the continuous curved surface is pressed against the fixed disk end face boss; during parking braking, the movable disk is driven to rotate relative to the fixed disk, and the rotational motion of the movable disk is converted into the linear motion of the movable disk, thereby pushing the brake block to clamp the brake disk to realize parking braking. The present invention has excellent durability and anti-overload design, the parking stroke and force are precisely controllable and adjustable, the safety factor is high, and the structure is simple and compact.

The invention discloses a silicon-based terahertz quintuple frequency multiplier based on a semi-closed coupling structure, comprising an input balun, a fourth harmonic frequency multiplication unit, an interstage transformer, a single-balanced mixer unit and an output balun. A single-ended fundamental wave signal is converted into a differential signal by the input balun and injected into the frequency multiplication unit. At the same time, a differential signal is split from the differential port of the input balun as the local oscillator of the mixer unit. The frequency multiplication unit generates a fourth harmonic and injects it into the source end of the mixer unit in a single-ended mode as an intermediate frequency signal. The mixer unit mixes the fundamental wave and the fourth harmonic to generate a five-fold frequency differential signal, and the output balun converts the differential signal into a single-ended output. Both the input balun and the output balun adopt a semi-closed coupling structure to reduce the coupling loss of passive devices. The structure has the characteristics of strong coupling and high design freedom, solves the problem of large loss of the passive coupling structure of the silicon-based millimeter-wave terahertz circuit, and improves the output power of the terahertz frequency multiplier.

The invention discloses a manufacturing method of a light-weight uniform-light-emitting vehicle logo. The manufacturing method comprises the following steps that 1, product surface patterns, colors, circuits and touch points are printed on a polycarbonate flexible membrane; step 2, pasting an electronic element and an LED lamp bead on a touch point on the front surface or the side surface of the polycarbonate flexible diaphragm through a microwave single-mode resonant cavity; 3, the printed polycarbonate flexible membrane is put into a high-pressure forming mold, and the 3D flexible lamp panel in the needed shape is manufactured; 4, an upper shell is subjected to injection molding firstly, and if the light-emitting vehicle logo emits light positively, a light uniformizing layer is arranged in the PC or PMMA upper shell; if the light-emitting vehicle logo emits light laterally, a light uniformizing layer, a light guide plate and a reflector plate are sequentially arranged in the PC or PMMA upper shell; then the lamp panel is subjected to reinforcement treatment, the upper shell is subjected to injection molding, and finally the vehicle logo upper shell and the vehicle logo lower shell are subjected to integrated injection molding. The light-emitting vehicle logo prepared by the method is uniform in light emitting, the thickness of parts can be as low as 5mm, and the weight can be reduced by 60-87.5%.

The present invention discloses a small-sized wavelength tunable semiconductor laser. It comprises two resonant cavities with different optical lengths, both of which comprise a first reflection surface, a polymer imaging coupler and a second reflection surface, and the two resonant cavities are arranged in a straight line along the same axis, and the second reflection surfaces of the two cavities are connected by a deep-etched waveguide to couple the two resonant cavities; the two polymer imaging couplers, the two second reflection surfaces and the deep-etched waveguide constitute a half-wave coupler, which has wavelength selective loss to achieve the best single-mode characteristics, and at the same time achieves wide-range wavelength tuning through the vernier effect. The present invention achieves small-sized tunability of a channel spacing of 400 GHz to 800 GHz through the small volume feature of the polymer imaging coupler, and does not require the production of gratings, simplifies the process, has a simple and compact structure, and is simple to control by tuning the channel through a single electrode, and has the potential to integrate modulators and photodiodes on a chip, and has the advantages of small size, low cost, and wide-range wavelength tunability.

The invention provides a multi-dimensional vibration platform with oppositely-arranged double-sandwich piezoelectric actuators and an excitation method of the multi-dimensional vibration platform, and belongs to the technical field of high-frequency vibration engineering and micro-nano machining.The vibration platform comprises a center platform, the two oppositely-arranged piezoelectric actuators, two end covers and two bolts, wherein the center platform is integrated with the tail end platform, the two flexible hinges and the two amplitude-change poles, and the center platform is slender and is in mirror symmetry about the longitudinal symmetry plane of the tail end platform. The piezoelectric actuator comprises a longitudinal vibration ceramic group, a bending vibration ceramic group around the Y axis and a bending vibration ceramic group around the Z axis, translation along the X / Y / Z axis and rotation around the Y / Z axis can be realized through in-phase or anti-phase excitation different combinations under the condition of not increasing extra driving channels, and five-degree-of-freedom high-frequency micro-vibration output can be achieved at most. The structure has high symmetry, low parasitic vibration, compact size and high integration, and is suitable for precise engineering scenes such as micro-nano processing, laser-assisted manufacturing, cell manipulation and active vibration suppression.

The invention relates to the technical field of FPGAs (Field Programmable Gate Array), in particular to an FPGA-based YOLOv5 hardware acceleration method, which comprises the following steps of: constructing an FPGA to accelerate a YOLOv5 network; performing signed integer quantization on the floating-point number of the acceleration operation; a three-input two-stage compression Compressor adder is constructed, and the addition of the acceleration operation is calculated; the multiplication of the acceleration operation is calculated; carrying out parallel partitioning on the Compressor adder, respectively calculating the calculation time delays of multiplication and addition of the input feature map, and carrying out parallel calculation of a ternary addition tree; the two IFMs are used for processing an input feature map, and the one OFW is used for processing an output feature map. The problem that when YOLOv5 is deployed on an edge device and an embedded device through an FPGA, the reasoning speed is low is solved.

The invention provides a transparent composite material with a sandwich structure and a preparation method thereof, and relates to the technical field of materials. Specifically, the transparent composite material comprises a first panel, a core layer and a second panel which are connected in sequence, the core layer comprises at least one of PC (polycarbonate), PMMA (polymethyl methacrylate), PVC (polyvinyl chloride), PET (polyethylene terephthalate) or PP (polypropylene); the first panel and the second panel comprise a fiber reinforced transparent material, and the fiber reinforced phase comprises at least one of E-alkali-free glass fibers, S-2 glass fibers, R-glass fibers, T-glass fibers, or HS-glass fibers. The transparent composite material has good mechanical strength on the premise of high light transmittance, the core layer provides overall rigidity and shear bearing capacity, the panel material bears bending and pressure loads, the strength of the composite material is improved, and the transparent composite material has good machinability and design freedom degree.