1341 results about "Bilayer" patented technology

The invention relates to the technical field of laser spectrum detection, in particular to an LIBS (Laser-induced Breakdown Spectroscopy) spectrum noise reduction method, system and equipment based on adaptive threshold wavelet transform and a storage medium. Acquiring an original spectral signal of the laser-induced breakdown spectroscopy; performing five-layer multi-layer wavelet decomposition on the original spectral signal by adopting a db4 wavelet basis function to obtain a high-frequency coefficient and a low-frequency coefficient of each layer; calculating a noise intensity standard deviation based on the detail coefficient of the highest decomposition layer; dynamically determining the optimal value of the regulation factor through a double-layer optimization strategy combining a grid search method and a golden section iterative optimization method; constructing an adaptive threshold value based on the noise intensity standard deviation and the adjustment factor; carrying out threshold value processing on the high-frequency coefficient by adopting a self-adaptive threshold value; and performing wavelet reconstruction on the processed high-frequency coefficient and low-frequency coefficient, and outputting a denoised spectral signal. While the LIBS spectral signal-to-noise ratio is remarkably improved, the spectral feature form is completely reserved, and reliable technical support is provided for laser-induced breakdown spectroscopy detection in a complex industrial environment.

The invention relates to the technical field of integrated circuit manufacturing, in particular to a precise electroplating control system and method for an electroplated layer of a double-layer circuit board, and the method comprises the steps: building a multi-physical field coupling simulation model, and simulating the internal current density and ion concentration distribution of a via hole; constructing a mapping relation between the current density and the side wall electroplating thickness based on a simulation result, and predicting the electroplating thickness; through thickness prediction feedback, a time sequence adjustable pulse current control strategy is designed, the pulse amplitude, the duty ratio and the on-off period are dynamically adjusted, and current distribution optimization is guided; the state of the electroplating process is sensed in combination with real-time monitoring and analysis of multi-source parameters of electrode potential, conductivity and fluid velocity; and based on the prediction model and the real-time parameters, adjusting the pulse waveform and the time sequence through closed-loop compensation. According to the method, the uniformity and controllability of the thickness of the electroplated layer on the side wall of the via hole can be remarkably improved.

The invention discloses a penetration discrimination method and system suitable for a double-layer dam foundation, and the method comprises the steps: S1, obtaining the geological parameters of a double-layer dam, and forming a geological parameter set; s2, constructing a seepage numerical model of the double-layer dam foundation, simulating the seepage field distribution condition of the double-layer dam foundation at each grid node, and obtaining seepage field data; s3, grid node seepage force is calculated, and a potential seepage failure area is determined; s4, monitoring pore water pressure and seepage flow changes of the preset monitoring points in the potential seepage failure area; s5, constructing a seepage failure judgment model, and outputting a seepage judgment result; and S6, performing grading processing according to the judgment result of seepage failure, and outputting grade seepage early warning information through a seepage grading model. According to the method, judgment, real-time monitoring and graded early warning of seepage damage of the double-layer dam foundation are achieved, and the safety of the heterogeneous double-layer dam is guaranteed.

The invention discloses a poly-Si film preparation method based on a vertical double-layer hot wire array thermal field design, which changes the surface temperature of a hot wire and the range of a cracking high-temperature region by adjusting the interlayer spacing of a double-layer hot wire array and the current of the double-layer hot wire, expands the cracking time and the cracking space of silane, promotes secondary cracking of the silane, and improves the yield of the poly-Si film. Components and concentration distribution of a silane cracking intermediate product reaching the surface of the substrate can be effectively controlled, and the ratio of SiH / SiH2 active groups is increased; and depositing the poly-Si thin film under the vacuum of 0.5 Pa-5. 0Pa, the substrate temperature of 200-560 DEG C and the deposition time of 10-60 minutes, after deposition is finished, raising the substrate temperature to 200-650 DEG C, and carrying out vacuum annealing on the grown poly-Si thin film to obtain the high-crystallization-rate poly-Si thin film. According to the method, the poly-Si thin film is grown by using a vertical double-layer hot wire array thermal field design, a high-temperature hot wire silane cracking technology and a vacuum annealing technology, and the crystallization quality of the poly-Si thin film can be obviously improved.

The invention provides a silicon-carbon negative electrode material as well as a preparation method and application thereof, and relates to the technical field of lithium ion batteries. The silicon-carbon negative electrode material comprises an inner core and double coating layers, nanometer silicon and graphite sheets are tightly combined through electrostatic interaction to form the inner core, and the outer surface of the inner core is sequentially coated with a graphene carbon coating layer and a titanium dioxide coating layer from inside to outside. The nanometer silicon and the graphite flake in the inner core of the silicon-carbon negative electrode material are tightly combined through electrostatic interaction, so that the stability of the inner core is enhanced, and the conductivity of the negative electrode material is also enhanced; the graphene carbon coating layer and the titanium dioxide coating layer are used as protective shells to inhibit volume expansion of silicon and ensure good contact between nano silicon and graphite flakes, so that side reactions are reduced; through the synergistic effect of the inner core and the double coating layers, the silicon-carbon negative electrode material has high specific capacity, good cycle performance and high capacity retention rate. The preparation method is simple, raw materials are easy to obtain, cost is low, and the method is suitable for industrial production.

The invention discloses an S-shaped micro-channel heat dissipation device with a double-layer turbulent flow structure and a use method, belongs to the field of liquid cooling heat dissipation, and is suitable for heat dissipation of a high-heat-flux device or a heat conduction device. The device comprises a base, a cover plate, a micro-channel body, turbulent flow columns, a flow guide structure, O-shaped sealing rings and quick-screwing connectors, the micro-channel body is provided with S-shaped channels which are vertically symmetrical, the turbulent flow columns are evenly arranged in the centers of the channels, and the top ends of the turbulent flow columns are flush with the end face of the micro-channel body. The turbulent flow columns can be rectangular columns or water-drop-shaped columns which are arranged in a single row or multiple rows at equal intervals and are matched with the flow guide structure to achieve efficient flow division of cold and hot fluid and interlayer heat interaction. Fluid mixing is strengthened through the centrifugal force of the S-shaped channel, a heat boundary layer is destroyed by the turbulent flow columns, and the problems that a traditional straight channel is low in heat exchange efficiency and uneven in temperature distribution are solved. Deionized water or nanofluid is selected as cooling liquid, closed circulation is formed by entering and exiting of the cooling liquid through the quick-screwing connector, and the adaptive scene and the comprehensive performance of the device are further expanded through the multiple rows of turbulent flow columns or the water-drop-shaped turbulent flow columns.

The invention relates to the technical field of X-ray detection, and discloses an X-ray detection method and detector for detecting various densities and materials, and the method comprises the steps: carrying out the penetration imaging of an X-ray beam through a double-layer TFT detector structure; forming a first common energy X-ray image on the first TFT imaging layer for X-rays penetrating through the detected object, and forming a first high-energy X-ray image filtered by the copper filter layer on the second TFT imaging layer; performing preprocessing to obtain a second ordinary energy X-ray image and a second high-energy X-ray image; performing dual-energy-domain feature extraction, and constructing an effective atomic number map and a material density map; and executing feature space clustering analysis and decision tree classification, and outputting a final detection result. According to the invention, the image information of different energy domains is effectively integrated, the recognition capability of a mixed material and a complex structure is enhanced, the service life of a TFT detector is prolonged, and the system operation cost is reduced.

The invention belongs to the technical field of new energy and energy saving, and particularly relates to a wind-light-load combined extreme scene extraction method and device, electronic equipment and a storage medium. Comprising the following steps: S1, based on a principal component analysis method, carrying out feature dimension reduction on each moon wind-solar charge sequence vector, and avoiding direct clustering on high-dimensional vectors; s2, establishing an extreme scene extraction model based on a scene difference degree maximum principle, extracting the most representative extreme scene from the wind-light load scene of each month, and providing correct classification of the conventional scene and the extreme scene for a subsequent double-layer MCMC model; according to the wind-light-load combined extreme scene extraction method, direct clustering of high-dimensional vectors is avoided by means of feature dimension reduction, extreme scenes in historical scenes are effectively extracted, and correct classification of conventional scenes and extreme scenes is provided for subsequent scene generation by adopting a double-layer MCMC model.

The invention provides a distributed feedback laser with a double-layer grating structure, and relates to the technical field of lasers, the laser forms an InGaAlAs multi-quantum well active region, an upper sampling grating layer and a lower phase shift grating layer on an n-type InP substrate in sequence, the upper grating layer is designed based on a reconstruction equivalent chirp technology, and the lower phase shift grating layer is designed based on a reconstruction equivalent chirp technology. Two sections of asymmetric modulation areas with sampling periods linearly gradually changing in opposite directions are arranged in the axial direction of the resonant cavity, and the lower grating layer is a quarter-wave phase shift grating matched with the period of the upper seed grating. Through the synergistic effect of equivalent phase modulation and phase shift generated by the double-layer grating, the photon density distribution in the cavity can be improved, the longitudinal space hole burning effect can be weakened, the sensitivity to end face phase fluctuation can be reduced, high single-mode power and large modulation bandwidth can be realized in a wide temperature range, and the double-layer grating is suitable for a high-speed optical communication and coarse wavelength division multiplexing transmission system.

The invention relates to the technical field of fluorescence sensing, in particular to a preparation method and application of an Nd (III)-based hydrogen bond organic framework crystalline material. According to the Nd (III)-based hydrogen bond organic framework crystalline state material, Nd (III) serves as a central metal ion and is coordinated with 9 oxygen atoms, and adjacent Nd (III) are connected through H2 (4-CPCA) ligands to form a one-dimensional chain structure. One-dimensional chains are bridged through H2 (4-CPCA) ligands to form a two-dimensional double-layer planar structure, and two-dimensional surfaces are further stacked through the interaction of a large number of intermolecular hydrogen bonds to form a three-dimensional supramolecular structure. The Nd (III)-based hydrogen bond organic framework crystalline material has good fluorescent property and stability, and can be applied to the field of fluorescence sensing.

A solid-state electronic miniature clock featuring a multi-layered silicon chip. A first circuit layer includes an electron paramagnetic resonance sensor, while the second layer comprises a silicon substrate with an etched trench housing single atom-doped fullerene molecules. Magnets are strategically placed on the silicon substrate and a third circuit layer to establish a baseline magnetic field. The chip incorporates through silicon vias (TSVs) filled with copper, forming a copper coil for enhanced antenna performance. Thermal management is achieved through vacuum cavities for isolation, strategically placed metals for heat generation, and thermo-electric materials, such as a bilayer of Bi$_2$Te$_3$ and Bi$_2$Se$_3$, for temperature regulation. A feedback loop monitors and adjusts the temperature, ensuring stability. Fabrication techniques include Deep Reactive Ion Etching (DRIE), electrochemical deposition, and photolithographic patterning, providing precise control over the chip's structure and functionality.

The invention relates to a fault arc-caused fire early warning method based on multi-sensor fusion, and belongs to the field of fault arc fire. The method comprises the following steps: establishing an arc electrical fire cause fault simulation test platform, selecting a typical single load and a combined load to perform a test before normal operation of a line and the occurrence of an arc cause fire, and establishing a fault arc waveform database and an arc fire database; the power-on detection method for the fault arc detection device is based on dictionary learning, current characteristics are represented through a sparse matrix, and fault classification is carried out in combination with an SVM. The fluctuation range of a plurality of characteristic quantities of the line in a normal state and when a fault arc occurs is analyzed, a threshold value is determined according to the periodic increase ratio of the characteristic quantities in different states, a final combined load detection threshold value is formed by complementation of a plurality of threshold values, and fault arc detection is realized; and based on the arc fire database, training a double-layer LSTM model under Bayesian optimization, and identifying multi-sensor signals in a time window to realize fire early warning.

The invention discloses a near-field focusing microwave thermal therapy device and method based on a Huygens metasurface. The device comprises a feed source antenna, a Huygens metasurface array and a biological tissue model. The feed source antenna is a 5.8 GHz double-ridge horn antenna and is used for transmitting x-polarized electromagnetic waves; the Huygens metasurface array is formed by periodically arranging double-layer through-hole-free Huygens units, anti-symmetric E-shaped metal patterns are symmetrically arranged on the upper surface and the lower surface of the single-layer PCB substrate, and phase regulation and efficient transmission are achieved by adjusting unit structure parameters; the biological tissue model is of a two-layer structure attached to the Huygens metasurface array, electromagnetic waves emitted by the feed source antenna are subjected to phase compensation regulation and control through the Huygens metasurface array, and then near-field focusing is achieved on the surface layer of the biological tissue, so that the electric field intensity, the SAR value and the temperature of a target area reach design threshold values respectively, and the target area is obtained. And local precise heating of electromagnetic resonance and phase regulation is formed. According to the invention, an efficient, stable and easy-to-implement technology is provided for local precise heating in microwave hyperthermia.

The invention belongs to the field of biological functional materials, and discloses rare earth up-conversion nanoparticles as well as a preparation method and application thereof. The rare earth up-conversion nanoparticles comprise an inner core and a shell layer, and the shell layer is formed by growing on the surface of the inner core through a one-pot method; the inner core is formed by taking beta-NaYF4 as a matrix and doping 0.4%-0.6% of Tm and 25% of Yb with rare earth nanoparticles; the chemical composition of the shell layer is NaYF4; the particle size of the core-shell double-layer structure of the rare earth up-conversion nanoparticle is 246.7 + / -43.2 nm; the polymer HPMCP is used for wrapping up-conversion nanoparticles and a prodrug for drug delivery and enteric release; 800nm up-conversion light generated by irradiation of low-power 980nm laser is used for nano material tracking, and ultraviolet up-conversion luminescence is generated under irradiation of high-power 980nm near-infrared laser to decompose prodrugs for drug release.

The invention discloses a resistor-loaded double-layer electric connection rotary symmetrical oscillator ultra-wideband antenna. The antenna comprises a dielectric substrate, a double-layer rotary symmetrical oscillator, a pair of metal through holes and a chip resistor. Wherein the double-layer rotationally symmetrical oscillator comprises a front radiation arm 1, a front radiation arm 2, a back radiation arm 3 and a back radiation arm 4, and each radiation arm is composed of a planar trapezoidal gradual change structure, a planar rectangular structure and a rotationally symmetrical tail end branch knot loading structure; the double-layer rotary symmetrical dipoles are connected through a pair of metal via holes, the planar resistor is loaded at a gap between the back radiation arms 3 and 4, and the feeding point is located at a gap between the front radiation arms 1 and 2. The antenna has the performance characteristics of ultra wide band and omnidirectional radiation, has the structural characteristics of ultra narrow size and ultra low profile, and is suitable for communication application scenes with limited space.

The invention relates to the field of photovoltaic equipment, and discloses a large vacuum chamber provided with a double-layer gas flow uniformizing structure, and the double-layer gas flow uniformizing structure comprises a pipeline box, and an upper flow uniformizing assembly and a lower flow uniformizing assembly which are arranged on the upper surface and the lower surface of the pipeline box. The pipeline box is located in the middle inside the cavity. The air inlet pipe comprises an upper-layer air inlet pipe and a lower-layer air inlet pipe which independently control air inlet. The upper flow uniformizing assembly sequentially comprises a first sealing ring, a diffusion flow uniformizing plate, a second sealing ring and a net-shaped flow uniformizing plate from bottom to top. Diffusion flow-uniformizing holes are formed in the diffusion flow-uniformizing plate, the diffusion flow-uniformizing holes are dispersed from the center hole to the periphery in a corrugated mode, and the farther the diffusion flow-uniformizing holes are away from the center hole, the denser the diffusion flow-uniformizing holes are. And the center of the diffusion uniform flow plate is positioned above the upper-layer air inlet. And uniformly distributed net-shaped flow uniformizing holes are formed in the net-shaped flow uniformizing plate. The vacuum breaking efficiency can be improved, the gas distribution uniformity of the cavity can be improved, the silicon wafer falling rate is reduced, and the yield is improved.

The invention relates to the technical field of remote sensing surveying and mapping, in particular to a multi-frame wide-area InSAR deformation result fusion method, which aims at the splicing problem of multi-frame InSAR deformation under a large spatial scale, performs optimization on the basis of a double-layer triangulation network and a local extraction method, and performs splicing according to dot-shaped and planar deformation storage characteristics. LOS deformation of each frame of image is converted into a vertical direction; and then on the basis of the double-layer triangulation network model, a genetic algorithm and PSO optimization are used as an improved algorithm for dotted deformation data homonymy point pairing to solve the many-for-one condition during registration. And under the condition of ensuring that the space position offset of the overlapping area is small, the offset of adjacent planar data is calculated by utilizing an optimized local extraction method, so that the deviation of adjacent deformation results in a large range is solved. And finally, generating a wide-area InSAR deformation product with consistent space reference and high availability based on two optimization algorithms.

The invention discloses superfinishing grinding equipment for soft magnetic ferrite core production, and mainly relates to the technical field of superfinishing grinding. Comprising a grinding disc and a rotating disc which are partially intersected, a plurality of station holes penetrate through the rotating disc, an annular tray is arranged below the rotating disc, each station hole comprises an inner hole site and an outer hole site which are communicated, the inner hole site is small, the outer hole site is large, the rotating disc comprises an upper disc piece and a lower disc piece which coaxially and synchronously rotate, and a locking arc-shaped positioning piece is arranged between the two disc pieces. The end face of the side, close to the axis of the rotary disc, of the positioning piece is an arc-shaped positioning curved surface coaxial with the rotary disc, the minimum distance between the inner hole position and the axis of the rotary disc is d, and the difference value of the radius of the positioning curved surface and d corresponds to the diameter of a magnetic core workpiece. The two ends of the positioning piece are provided with guide pieces bent in the direction away from the circle center of the rotary disc. The double-end-face machining device has the beneficial effects that continuous and efficient operation in double-end-face machining is achieved, automatic feeding and discharging are supported, and the machining precision is greatly improved.

The invention relates to the technical field of acoustic function material structure design, in particular to a Kresling origami-based local resonance phononic crystal, which comprises a substrate and a vibration reduction array embedded on the substrate, the vibration reduction array comprises a plurality of unit cell structures arranged in an array. Each unit cell structure comprises at least two spiral Kresling paper folding structures, and lead injection holes penetrating through the Kresling paper folding structures are formed in the Kresling paper folding structures. The substrate is one of an Archimedes spiral parallel plate, a chessboard embedded paper-cut, a double-layer Miura origami or a bistable shell based on a shape memory polymer; the material of the Kresling origami structure is lead, the density is 11600 kg / m < 3 >, the elastic modulus is 20.80 GPa, and the Poisson ratio is 0.369. According to the local resonance photonic crystal provided by the invention, through the unique geometric characteristics, a remarkable vibration band gap is generated in a low-frequency band, and vibration propagation in a specific frequency band is effectively inhibited; according to the Kresling paper folding structure, diversified vibration band gap configuration can be achieved by adjusting the folding angle and the number of layers.

The invention discloses a grinding state on-line monitoring method based on multilayer data fusion and a mathematical combined driving model, and the method comprises the steps: carrying out the signal collection through a multi-source sensor, carrying out the fusion according to a corresponding weight, and carrying out the noise reduction through stacking self-coding. When signals are extracted, frequency domain multi-dimensional features are fed into the residual neural network and the bidirectional double-layer LSTM fusion model after being subjected to Pearson correlation screening, and single-working-condition grinding state recognition is achieved. 10 types of discrete grinding states are defined, and a physical driving type empirical formula for working condition and monitoring signals and working condition and state characterization is established based on working condition parameters such as grinding depth and main shaft rotating speed. And generating a training data set by using an empirical formula, and training a cross-working-condition monitoring model through a transfer learning mechanism to realize cross-working-condition identification. According to the method, online accurate recognition of the grinding state is achieved, the limitation of traditional single-working-condition monitoring is broken through, and the problem of repeated data collection training is solved through the physical law of an empirical formula.

The invention relates to a silicon-carbon negative electrode material and a preparation method thereof. The silicon-carbon negative electrode material comprises a carbon skeleton, silicon particles distributed in pores of the carbon skeleton and a carbon layer coating the carbon skeleton, wherein the carbon skeleton adopts porous carbon, and the carbon layer is of a double-layer gradient coating structure. According to the silicon-carbon negative electrode material and the preparation method thereof, by controlling the deposition mode, deposition temperature, deposition time and the like of the silicon source gas and the coating mode, coating flow, coating time and the like of the coating gas, uniform deposition of silicon particles in pores of a carbon skeleton and uniform coating of a gradient coating type carbon layer are realized; the growth of silicon grains and the formation of rich silicon on the surface are inhibited, the gas production of the material is reduced, the tap density of the material is improved, the tar residue in the material is eliminated, and the comprehensive electrochemical performance is considered.

The invention relates to a super-flexible supercapacitor with a multi-layer seamless interlocking interface and a preparation method of the super-flexible supercapacitor. The super-flexible supercapacitor takes a carbon nanotube or a composite film thereof as an electrode; and polyanion gel (polyacrylamide / polyacrylic acid / poly (3-sulfonic acid propyl methyl acrylic acid potassium salt) and polycation gel (polyacrylamide / polyacrylic acid / poly (methacryloyloxyethyl trimethyl ammonium chloride) are used as the double-layer heterogeneous electrolyte. A covalent connection electrode / electrolyte interface is constructed through anchoring interface polymerization, and double-layer gel electrolyte with electrostatic attraction and mutual entanglement is constructed through in-situ polymerization, so that the super-flexible supercapacitor with a multi-layer seamless interlocking interface is realized. Compared with the prior art, the super capacitor has super-strong interface toughness and interface adhesion, can resist mechanical deformation including bending, folding, twisting, winding, extruding, knotting and the like, the capacity retention ratio is greater than 95% after the super capacitor is folded for hundreds of thousands of times, and the capacity retention ratio is greater than 89% after the super capacitor is circularly charged and discharged for hundreds of thousands of times.

The invention discloses a passivation contact type back contact solar cell and a preparation method thereof, the cell comprises a crystalline silicon substrate, the front surface of the crystalline silicon substrate is a passivation anti-reflection layer, and the back surface of the crystalline silicon substrate is sequentially provided with a first tunneling layer, a first polycrystalline silicon layer, a second tunneling layer, a second polycrystalline silicon layer, a passivation layer and a metal electrode from inside to outside, the first polycrystalline silicon layer comprises a first n + polycrystalline silicon region, a first p + polycrystalline silicon region and a first isolation region, the second polycrystalline silicon layer comprises a second n + polycrystalline silicon region, a second p + polycrystalline silicon region and a second isolation region, and the doping concentration of boron in the first p + polycrystalline silicon region is lower than that of boron in the second p + polycrystalline silicon region; the doping concentration of phosphorus in the first n + polycrystalline silicon region is lower than the doping concentration of phosphorus in the second n + polycrystalline silicon region. A double-layer tunneling polycrystalline silicon structure is adopted on the back face of the cell, and low metal contact compounding, low non-metal contact area compounding and low contact resistivity can be met at the same time.

The invention provides a double-layer coated porous silicon carbon negative electrode material and a preparation method thereof.The preparation method comprises the steps that a carbon precursor and a doped precursor are evenly mixed, inert gas is introduced into a chemical vapor deposition furnace, the temperature is adjusted to 400-500 DEG C, meanwhile, silicon source gas is introduced, the reaction time is controlled to be 500-1000 minutes, and a porous silicon carbon framework is obtained, the doped precursor comprises a silicon source material; heating the porous silicon carbon skeleton to 450-550 DEG C, introducing oxygen-containing gas, and reacting for 200-800 minutes to obtain an oxygen-silicon layer deposited on the surface of the porous silicon carbon skeleton; dispersing the porous silicon carbon skeleton with the oxygen silicon layer in a mixed solvent, adding a modified coupling agent and a lithium salt, stirring for 1-5 hours at room temperature, adding a polymer solution after stirring, stirring for 1-5 hours at room temperature, generating a polymer layer on the oxygen silicon layer, and washing and drying to obtain the double-layer coated porous silicon carbon negative electrode material. Therefore, the cycle performance of the negative electrode material is effectively improved.

The invention relates to a large-size double-layer splicing type ferrite magnetic shielding structure, in particular to a low-noise magnetic shielding barrel structure which is particularly suitable for an ultra-high sensitive magnetic field and inertial measurement device and miniaturization integration application of the ultra-high sensitive magnetic field and inertial measurement device. The magnetic shielding barrel is manufactured by splicing single large-size ferrite blocks into a double-layer cylinder. And the seam at the splicing part of the inner layer is blocked by the ferrite on the outer layer, so that the splicing does not generate large magnetic flux leakage. The double-layer configuration improves the shielding coefficient and reduces the magnetic noise at the same time. The novel large-size double-layer splicing type ferrite magnetic shielding structure shielding barrel is simple in processing technology, the shielding effect is not affected while the material cost is saved, the magnetic noise is reduced through the double-layer barrel structure, and the defect that the magnetic noise caused by a traditional single-layer ferrite magnetic shielding barrel cannot be further reduced is overcome.

The invention relates to the technical field of antennas, and further relates to a wide-beam multi-vibrator planar antenna supporting Tiantong Beidou frequency bands, which comprises a multi-vibrator radiation array element layer, a coplanar feed-amplitude shaping network, a stepped impedance matching section, a low-loss double-layer dielectric laminated layer and a metal reflecting plate, the outermost side of the multi-oscillator radiation array element layer is a PCB lamination layer; the coplanar feed-amplitude shaping network comprises a radiation patch, and different current amplitudes are provided for all oscillators through phase shift sections with different electric lengths so as to ensure that the half-power beam width can still reach 90 degrees or above under the condition of the shortest Beidou wavelength; the stepped impedance matching section is a pi-shaped converter formed by connecting three microstrip lines with different widths in series; and the low-loss double-layer dielectric laminated layer is used for solving the minimum distance between the metal reflecting plate and the PCB laminated layer according to the theoretical minimum gain. The antenna has the advantages of compact structure, stable gain and wide beam width.

The invention discloses a double-layer piezoelectric sensor and an application and method of the double-layer piezoelectric sensor in representing beta-phase polyvinylidene fluoride membrane adsorptive pollution, a piezoelectric beta-phase polyvinylidene fluoride membrane is a porous membrane formed by a blending system of polyvinylidene fluoride and ionic liquid and has a beta-phase crystal structure and a piezoelectric response characteristic, and the piezoelectric beta-phase polyvinylidene fluoride membrane is prepared by spin-coating a PVDF solution on a chip. The double-layer piezoelectric sensor containing the beta-phase polyvinylidene fluoride membrane is obtained, and QCM-D detection is carried out to characterize the adsorptive pollution condition of the beta-phase polyvinylidene fluoride membrane. Adsorption and desorption behaviors of organic matters with different dissolvability and mixtures thereof on the beta-phase PVDF membrane layer are represented, the adsorption result is matched with the hole blocking resistance in the actual membrane pollution process, and the hole blocking resistance is calculated by monitoring the fifth overtone of the piezoelectric quartz sensor. And the quality of soluble organic matters adsorbed on the PVDF surface and the property of an adsorption layer can be evaluated by using a frequency change value and a dissipation value, and a scheme is provided for researching the pollution behavior of the beta-phase polyvinylidene fluoride membrane.

The invention discloses a double-shell-layer fire extinguishing microcapsule. The double-shell-layer fire extinguishing microcapsule comprises a core material, a first shell layer and a second shell layer, wherein the core material is coated with the first shell layer, and the first shell layer is coated with the second shell layer. By optimizing the components of the core material, reducing the volatility of the core material, improving the coating rate and arranging the double-layer microcapsule structure, the first shell layer can be formed under the low-temperature condition and is excellent in compactness, escape of the core material in the reaction can be effectively reduced, the coating rate and the yield of the microcapsule are further improved, and after full crosslinking, the product yield is improved. The second shell layer can further improve the mechanical performance of the microcapsule, the hydrophobicity and compactness of the second shell layer are beneficial for preventing polyurea and melamine resin from absorbing water and deliquescing and preventing formaldehyde harmful substances from being continuously released, the safety of the microcapsule is improved, and the microcapsule has a wider application scene and can quickly respond to the fire temperature.

The invention discloses a closed double-layer stirring type photobioreactor, and relates to the technical field of microalgae culture. A double-layer special-shaped paddle combination is formed through the composite design of a four-straight-blade overall open turbine type (SK) and a three-blade left-handed push type spiral stirring paddle (TXL), paddle combination optimization is formed through the cooperative flow field design of the TXL paddle (lower layer) and the SK paddle (upper layer), axial-radial flow coupling is achieved, and the material exchange rate between gas and liquid is increased; according to the combined design of the double-layer special-shaped paddles, the proportion of a high-shear area is reduced to be lower than 12% through a wide-area low-strength shear mode of the TXL paddles, the shear stress is greatly reduced, and the problem that the shear stress is too high is solved; a dynamic rotating speed strategy is convenient to implement, and the mass transfer efficiency and the cell activity are both considered by adjusting the rotating speed in stages.

According to the device for reducing the temperature rise of the dry-type hollow high-capacity current-limiting reactor and the design method thereof, a double-layer rainproof device technology and a split type staggered ventilation structure are adopted to realize rainproof and heat dissipation decoupling; according to the invention, heat dissipation is carried out through annular grating ventilation holes in the vertical direction of a top-layer rainproof cap and a middle ventilation net between the top-layer rainproof cap and a bottom-layer rainproof cap, and a coupling simulation technology of a magnetic field-flow field-temperature field of a reactor is utilized to form a correlation between structural parameters of a double-layer rainproof device and a flow rate change rate of fluid in an air passage of an encapsulation chamber; a bidirectional coupling model of a flow field and a temperature field is established, and the synergistic effect of encapsulated radiation and convective heat transfer is solved through a finite element method. Through multi-field coupling simulation and parametric modeling, the problem of collaborative optimization of rainproof device design and electric reactor thermal performance is solved, the equivalent heat dissipation area is increased to 2-3 times that of a single-layer structure, the use amount of wires is reduced by 8-15%, the coil hot-spot temperature rise is reduced to 78K from 88K of a traditional structure, and the reduction amplitude reaches 11.4%.