1595 results about "Crystal structure" patented technology

The invention discloses a catalyst used for preparing acrylic acid and butyl ester by the dehydration of butyl lactate and a preparation method thereof. The catalyst is a composite catalyst, comprising a main catalyst A and auxiliary catalysts B, C, D and E, wherein, A is calcium sulphate, B is sulphuric acid, C is phosphate, D is alkaline matter and E is promoter. The preparation method comprises the steps as follows: five compositions A, B, C, D and E are sufficiently mixed, baked for 2-10 hours at the temperature of 200-800DEG C and formed for standby. The catalyst has high catalytic activation; under the catalysis of the catalyst, the molar yield reaches 75.1 percent and the molar selectivity of the acrylic acid and butyl ester reaches 71.5 percent. The preparation method has the advantages that the crystal structure of the main catalyst can be improved so as to be beneficial for carrying out the reaction; and the introduction of different auxiliary catalysts and quantities is helpful to improve the conversion ratio of the raw material and the product selectivity and is beneficial for improving the strength of the catalyst.

The invention discloses an application of a molybdenum disulfide-based piezoelectric catalytic material in a seawater uranium extraction material, and relates to the technical field of seawater uranium extraction, thiourea and sodium molybdate are used as precursors, and a MoS2 nanoflower with a specific 1T / 2H composite crystal structure is constructed through a hydrothermal synthesis technology. The method is placed in a uranyl nitrate solution, ultrasonic treatment is combined, efficient extraction of uranium can be achieved, and the method has potential application to extraction of uranium from seawater. The method is simple in process and environment-friendly, almost does not generate harmful waste in the synthesis process, does not need complex operation, and has good amplification preparation potential.

Provided are a polariton device, a polariton system, a method of manufacturing the polariton device, and a method of controlling the polariton device. The polariton device includes a cavity including a gain layer including a ferroic material that undergoes a phase transition into an asymmetrical crystal structure in response to an external stimulus, an upper reflective layer formed on top of the cavity, a lower reflective layer formed below the cavity, and a Rabi frequency controller configured to control a Rabi frequency of the polariton device by providing a stimulus to the gain layer.

The invention relates to a design method of a novel crystal structure based on a large language model, and belongs to the crossing field of artificial intelligence and material science. According to the design method, design requirements are recognized through a large language model, a first crystal design constraint is extracted, then an example crystal structure is retrieved from a crystal structure database, a second crystal design constraint is output, and the large language model learns the example structure and generates a first target crystal structure according to the second crystal design constraint. The structure is determined as a second target crystal structure after being checked, then the second target crystal structure is subjected to structural relaxation to obtain a candidate structure set, and the novel crystal structure is obtained through stability screening. According to the design method, dependence on large-scale training can be effectively eliminated, novel crystal structure discovery without additional training is realized, adaptive conversion oriented to diversified novel crystal discovery scenes is realized, a design target is automatically analyzed according to different user intentions and crystal generation task types, and a generation strategy is flexibly adjusted.

The invention relates to the technical field of machine learning potential molecular simulation, and provides a montmorillonite thermal conductivity prediction method based on NEP machine learning potential, and the method comprises the following steps: constructing a montmorillonite crystal structure model, carrying out first principle molecular dynamics calculation on the montmorillonite crystal structure model, introducing lattice distortion and atomic disturbance, and generating an initial structure set; performing static single-point DFT calculation on the initial structure set, and constructing a training data set; based on an NEP machine learning framework, utilizing the training data set to train and generate a potential function; optimizing the generation process of the potential function by adopting an active learning strategy; and performing thermal conductivity prediction verification on the potential function, and obtaining a thermal conductivity prediction result of the montmorillonite based on the potential function passing the verification. The defect that a traditional classical potential function depends on an empirical or semi-empirical model and is limited in precision and applicability is overcome, the problem that the dynamic behavior and the heat conduction mechanism of a complex material are difficult to accurately capture is solved, the calculation cost is reduced, and meanwhile the precision is kept.

The invention belongs to the field of computational chemistry, and particularly relates to a multi-parameter collaborative dynamic screening method for adsorbed species on the surface of a catalyst. Comprising the following steps that an initial crystal structure is constructed and optimized through VESTA software, and a stable crystal structure model is obtained through density functional theory optimization; integrating working condition parameters such as a solvent, pH and potential, and drawing a Bayer diagram to label adsorption species and a mapping relation; and calculating a zero charge point and capacitance to obtain electrochemical parameters, and determining stable adsorption species under actual reaction through constant potential molecular dynamics simulation. According to the scheme, a deep structure-activity relationship between an active site structure and catalytic activity under a working condition is established through integration of all working condition parameters, labeling of adsorption species by a Boubye diagram, constant potential molecular dynamics simulation and the like; the problems that a systematic method combined with actual working condition parameters is lacked in prediction of the adsorbed substances on the surface of the catalyst, and real adsorbed species are difficult to accurately screen are solved, and accurate capture and efficient screening are achieved.

The invention belongs to the technical field of energy materials, and provides a multi-functional-layer lithium manganate positive electrode material and a preparation method thereof and a lithium battery, the multi-functional-layer lithium manganate positive electrode material comprises a core body and a coating layer, the core body sequentially comprises a bulk-phase-doped lithium manganate matrix, an induction doping layer and a modification doping layer from inside to outside, the chemical general formula of the core body is Li < 1 + a > Mn < 2-b-c-d > M R < c > X < d > O < 4-e > Z < e >, bulk phase doping elements of the matrix are M and Z, a crystal face induction element is X, and a modification doping element is R; the coating layer is a compound comprising a coating element M '; a supported crystal face inducer is also adopted for further inhibiting the growth of the crystal face (111) and reducing the area of the crystal face (111) so as to form the positive electrode material of a polyhedral spinel crystal structure comprising at least 26 crystal faces, and the crystal face inducer comprises a phosphorus-containing compound, a boron-containing compound or at least + 5 valence metal salt; the Mn dissolution reaction is reduced, and the electrochemical performance of the lithium manganate is improved.

The invention belongs to the technical field of lithium ion battery materials, and discloses a preparation method of a high-first-effect small-particle single-crystal ultrahigh-nickel ternary positive electrode material. The method comprises the following steps: firstly, uniformly mixing an ultrahigh nickel ternary precursor with a lithium source and a tungsten source, performing mechanical densification and pressing to obtain a blocky solid, and then performing four-section program temperature control calcination to obtain a target material. The interface fusion resistance of single crystal growth can be reduced through mechanical densification; a part of the tungsten element forms a Li2WO4 coating layer, and a part of the dopant phase replaces Ni < 2 + >, so that grain growth can be inhibited, a crystal structure can be stabilized, and the first effect is improved; and the microstructure of the material can be accurately regulated and controlled through four-section temperature-controlled calcination. Through a coating-doping-single crystallization synergistic strategy, the electrochemical performance of the material in liquid and sulfide-based all-solid-state batteries is remarkably improved, the process is controllable, and the application prospect is wide.

The invention belongs to the technical field of flame-retardant materials, and particularly relates to a prismatic aluminum hypophosphite compound as well as a preparation method and application thereof. The prismatic aluminum hypophosphite compound is prepared from aluminum hypophosphite, layered montmorillonite and nano silicon dioxide, and the weight percentage of the layered montmorillonite is 0.043 to 0.087 weight percent and the weight percentage of the nano silicon dioxide is 0.0036 to 0.0181 weight percent based on 100 weight percent of the aluminum hypophosphite; the particle size D10 of the prismatic aluminum hypophosphite compound is 1-3 microns, the particle size D50 of the prismatic aluminum hypophosphite compound is 5-8 microns, the particle size D90 of the prismatic aluminum hypophosphite compound is 10-15 microns, the particle size D97 of the prismatic aluminum hypophosphite compound is smaller than 20 microns, and the prismatic aluminum hypophosphite compound is of a single prismatic crystal structure or a regular structure in which a plurality of prismatic crystals are mutually embedded. The prismatic aluminum hypophosphite compound provided by the invention has a specific morphology and is especially suitable for a polyurethane flame-retardant system.

The invention provides an artificial intelligence grading classification-regression combination prediction method for multi-class materials, and belongs to the technical field of material informatics and artificial intelligence. According to the method, a historical sample data set of material chemical composition and crystal structure information is obtained, a band gap value is divided into a plurality of intervals based on an equal width principle, and interval labels are generated. Key features are extracted, an SVM classification model is trained to predict a band gap interval, and then a multi-layer neural network regression model is utilized to predict a band gap value. If the highest confidence coefficient is higher than the threshold value, directly calling the multi-layer neural network regression model of the corresponding interval; and if the value is lower than the threshold value, multi-interval parallel regression and weighted fusion prediction are carried out. According to the artificial intelligence grading classification-regression combination prediction method for the multi-class materials, the precision and robustness of band gap prediction can be effectively improved, particularly, the performance is prominent when high and low band gap samples are distributed imbalanced, and a precise and reliable solution is provided for material band gap prediction.

The invention relates to the technical field of acoustic functional devices, and discloses an acoustic black hole lens based on a three-dimensional radial gradient refractive index phonon crystal structure and a design method, a three-dimensional radial gradient refractive index distribution function n (r) with a center convergence characteristic is constructed, and incident sound waves are continuously guided and efficiently focused to the center of the lens in the propagation process; combining the feasibility constraint of an additive manufacturing process, designing a few-negative micro-lattice structure unit for realizing the gradient refractive index distribution, and determining key geometric parameters of the few-negative micro-lattice structure unit; according to the refractive index distribution function n (r), radially arranging the micro-lattice units in a three-dimensional space, and constructing an initial lens model; the sound field distribution, focusing performance and energy convergence efficiency of the model are verified and iteratively optimized in a mode of combining analytical modeling and finite element method simulation, and a three-dimensional radial gradient refractive index photonic crystal acoustic black hole lens design model with wide-angle incidence compatibility and broadband response capability is obtained.

The invention discloses a sodium ion sulfide solid electrolyte with enhanced stability, the chemical composition formula of the solid electrolyte is Na3Sb1-xAsxS4-ySey, x and y are respectively molar ratios of As and Se, x is more than or equal to 0.1 and less than or equal to 0.5, y is more than or equal to 0.1 and less than or equal to 0.4, the solid electrolyte has a cubic phase crystal structure similar to Na3SbS4 and belongs to a space group, the side length of a cell is a = b = c = 7.19309, and the volume of the cell is V = 374.9457336; in the crystal structure, Sb and As are mixed to occupy the peak and center equivalent position 2a of a cubic unit cell; s and Se are mixed to occupy a 24g position, Na ions are filled in gaps of unit cells, Na1 occupies a 6b position, Na2 occupies a 2b position, and a covalent bond network is formed by the position occupied by the mixture of S and Se and the position occupied by the mixture of Sb and As. The solid electrolyte is low in cost, the ionic conductivity of the solid electrolyte is 10 <-3 > S / cm magnitude, and the solid electrolyte has excellent cycle performance and air stability.

The invention belongs to the field of photocatalytic preparation of hydrogen peroxide, and relates to a novel secondary amine linked covalent organic framework material (AR-COF) as well as a preparation method and application thereof. According to the material, tetraaldehyde phenyl porphyrin and 2, 5-diamino-1, 4-benzenediol dihydrochloride are subjected to a Schiff base reaction to synthesize an imine bond connected porphyrinyl covalent organic framework (IM-COF), and then synthesis post-modification (PSM) is performed on the imine bond connected porphyrinyl covalent organic framework (IM-COF) so that the imine bond connected porphyrinyl covalent organic framework (IM-COF) and sodium borohydride can be subjected to a reduction reaction to generate AR-COF. The photocatalytic stability of the material is maintained through modification after synthesis, the catalytic activity is improved, and the original crystal structure is not damaged. A photocatalytic hydrogen peroxide production experiment shows that the catalytic activity of AR-COF under 420 nm monochromatic light is superior to that of IM-COF, the yield under an oxygen condition reaches 7.79 mmol.g <-1 >. H <-1 >, and hydrogen peroxide can be stably produced. The method utilizes solar energy for green synthesis under mild conditions, and provides a safe and efficient method for hydrogen peroxide production.

The invention relates to the technical field of hydrogen storage alloys, in particular to a Ti-based hydrogen storage alloy and a preparation method and application thereof. The chemical formula of the Ti-based hydrogen storage alloy is TibZr (1.02b) CrcMn (1.6 c) Fe 0.4, b is larger than or equal to 0.92 and smaller than or equal to 0.95, and c is larger than or equal to 1.0 and smaller than or equal to 1.2. According to the invention, Ti or Cr is doped into a Ti0. 92Zr0. 1Cr1. 0Mn0. 6Fe0. 4 alloy matrix, and regulation and control of unit cell parameters and electronegativity are realized by means of alloying, so that the hydrogen compression material has a higher compression ratio, and the alloy crystal structure is stable, and has more excellent activation performance, longer cycle life and higher cycle stability.

The invention belongs to the related technical field of additive manufacturing, and discloses an electron beam melting wire liquid nitrogen copious cooling additive manufacturing method and system.The method comprises the steps that in the electron beam melting printing forming process, liquid nitrogen is sprayed to a molten printing wire under electron beam irradiation, and the liquid nitrogen is sprayed to the molten printing wire; the molten printing wires are subjected to nitridation reaction under the action of electron beams while being subjected to liquid nitrogen cryogenic cooling, so that the crystal structure of a formed part is regulated and controlled, and the mechanical performance is enhanced; and / or liquid nitrogen is sprayed to the printing wire material which begins to be solidified, so that the printing wire material is subjected to liquid nitrogen deep cooling, and the crystal structure of the formed part is regulated and controlled to achieve mechanical property enhancement. Liquid nitrogen is introduced into the electron beam additive manufacturing device for deep cooling, the extruded printing wire is solidified at an extremely high cooling speed after being melted, a large number of homogeneous nucleation sites are formed in a melting area due to the high supercooling degree, the solidification speed is high, a microstructure is customized into uniform and fine equiaxed crystals, the strength and toughness of the material are improved, and the production cost is reduced. The mechanical property is improved.

The invention relates to the technical field of photovoltaic solar cells, and discloses a perovskite thin film, a preparation method and application, the perovskite thin film is prepared from a perovskite precursor solution by adopting a one-step spin-coating method or a two-step deposition method, and the perovskite precursor solution comprises 2, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5-trimethyl-1, 3, 5- The perovskite material is prepared from 2, 4-oxazolidinedione, a raw material for synthesizing the perovskite material with the ABX3 crystal structure, and a solvent. According to the invention, 2, 4-oxazolidinedione (OD) molecules are simply introduced into a perovskite precursor solution, especially into an inorganic precursor solution (such as a lead iodide precursor solution), and the porous PbI2 can be obtained by utilizing the interaction between electron-donating groups in the OD molecules and lead iodide, so that when the organic ammonium salt is spin-coated in the second step, the porous PbI2 can be obtained. The organic ammonium salt solution can rapidly diffuse and fully react, so that the perovskite thin film with larger and more uniform crystal grains is obtained, and the residual amount of harmful PbI2 is remarkably reduced.

The invention relates to the technical field of suspension roasting, in particular to a flowing suspension roasting system and method for desiliconizing and purifying coal gangue. The system comprises a multi-stage preheating unit, a multi-stage cooling unit, a flowing suspension roasting furnace and a crystal form control device which are connected in sequence, and the method comprises the steps that coal gangue materials are subjected to multi-stage preheating, so that the materials are heated in stages; performing high-temperature roasting in a flowing suspension roasting furnace, and controlling the retention time of the material and the environment temperature in a crystal form control device so as to regulate and control the crystal form structure of the material. By accurately controlling the roasting process and optimizing material crystal form transformation, efficient removal of silicon in the coal gangue and efficient extraction of aluminum oxide are achieved, and the method has the advantages of being low in energy consumption, high in efficiency and good in environment friendliness and is suitable for large-scale industrial production.

The present disclosure relates to materials science using processing of crystallographic structure data and artificial intelligence, and more particularly to methods and apparatuses for estimating material properties from crystallographic descriptive data, wherein a computer-implemented method includes generating first data representing a crystal structure from crystallographic descriptive data; generating, in view of structural periodicity, second data representing an expanded supercell; converting the second data into input data as a four-dimensional tensor in which a first dimension corresponds to atom species and remaining dimensions correspond to coordinates of a discretized three-dimensional grid; supplying the input data to a neural network including convolutional layers and a self-attention mechanism to extract features; and estimating, from the extracted features, at least one material property of the material. Related apparatuses and non-transitory computer-readable media are also disclosed.

The invention provides a reverse generation type design method and system of a battery material based on a large language model. The method comprises the following steps: carrying out serialized representation on a crystal structure of a lithium ion battery material; constructing a material basic model, and training the material basic model based on the serialized representation result to obtain a trained material basic model; a multi-dimensional attribute virtual KV attention mechanism is introduced into the material basic model, and a property conditional generation model is obtained; accessing a property prediction head network to the material basic model, and performing supervised training on the material basic model to obtain a material property prediction model; and performing reinforcement learning training on the property conditional generation model to obtain an optimized property conditional generation model, and generating a crystal structure candidate set based on the optimized property conditional generation model. By means of the method, efficient, controllable and diversified generation of the hundred-atomic-scale complex crystal structure is achieved, and the precision and practicability of material reverse design are remarkably improved.

The application provides a mixed matrix membrane for efficient ion separation and a preparation method thereof, and belongs to the technical field of separation membranes.The application mixes an aluminum salt and sodium hydroxide in an organic solvent, then adds a heterocyclic organic ligand containing nitrogen to obtain a MOF precursor solution; adds polyimide into the MOF precursor solution to obtain a casting solution; pours the casting solution into a mold and performs vacuum heating, then performs peeling, soaks in ethanol, and then performs drying to obtain the mixed matrix membrane for efficient ion separation.The application realizes uniform dispersion of MOF-303 in the whole matrix by controlling the MOF loading, and constructs continuous ion channels by the uniformly dispersed MOF-303 crystal structure, so that the selectivity of the membrane to monovalent ions is further improved.The operation is simple, and the cost is low.

The invention discloses a niobium-doped and carbon nanotube continuously coated lithium iron nickel phosphate material and a preparation method thereof, and belongs to the technical field of lithium ion battery positive electrode materials. The niobium source and the phosphorus source are added step by step, the concentration gradient distribution of the niobium element in the material is realized, and niobium is preferentially doped in the [100] crystal orientation through three-section temperature control sintering, so that the bulk phase conductivity and the lithium ion mobility are remarkably improved, and the capacity loss caused by excessive doping is avoided while the lattice structure is stabilized. In addition, the carbon nanotubes and the nitrogen-containing carbon source have a synergistic effect, Li-N-C covalent bonds are formed on the surface of the material, the interface stability is enhanced, the interface side reaction is effectively inhibited, and the surface conductivity is improved. According to the method, through double modification of doping and coating, the problems of low conductivity and poor cycling stability of the lithium iron nickel phosphate material are successfully solved, and the final product shows excellent rate capability and long cycle life.

The application provides a leaching agent for removing thallium and beryllium in lithium residue and application. The leaching agent comprises a first leaching agent and a second leaching agent. The first leaching agent is an organic acid solution, the organic acid comprises a carboxyl group, and at least one of a hydroxyl group, a sulfhydryl group, a carbonyl group and a sulfonic acid group; the organic acid is a single organic acid or a mixed organic acid; the second leaching agent comprises a cation agent and a reducing agent, the cation agent can form at least one of K + , NH4 + , Mg 2+ , Na + , Fe 3+ in an aqueous solution, and the reducing agent comprises an inorganic reducing agent and / or an organic reducing agent. The organic acid in the first leaching agent can destroy the crystal structure of the lithium residue, and the groups such as the carboxyl group and the hydroxyl group can complex thallium and beryllium ions to make them more easily leached out. On this basis, the cation and the reducing solution in the second leaching agent accelerate the release of thallium and beryllium through ion exchange and reduction. The above leaching agent can remove thallium and beryllium in the lithium residue at the same time, and has a high removal rate of thallium and beryllium.

The invention provides a lithium-rich disordered rock salt positive electrode material as well as a preparation method and application thereof. The chemical general formula of the lithium-rich disordered rock salt positive electrode material is Li (1 + x) MpNqO (2-y) Xy, 0.3 < = x < = 0.6, p + q = 1, 0.5 < = p < = 0.9, 0.1 < = q < = 0.5, 0 < = y < = 0.4, and M comprises Fe and / or Mn; n comprises any one or a combination of at least two of Zr, Ti, Nb, Mo, W or V; x comprises a polyanionic group. The N element with higher valence is introduced into the lithium-rich disordered rock salt positive electrode material, and meanwhile, the polyanion group is introduced to jointly stabilize the crystal structure, so that the oxygen loss under high voltage is effectively inhibited, and the N element with higher valence can also reduce cation mixing and participate and stabilize the anion redox reaction, so that the lithium-rich disordered rock salt positive electrode material is more stable. The polyanion groups and the transition metal ions form strong covalent bonds, so that the cycling stability of the material is remarkably improved.

The invention provides a method and a system for generating a multiphase powder X-ray diffraction crystal structure. The method comprises the following steps: acquiring a powder X-ray diffraction experiment spectrum; the powder X-ray diffraction experiment spectrum is input into a decoupling encoder, a plurality of crystal structure target potential factors output by the decoupling encoder are obtained, and the decoupling encoder is constructed based on independence loss among the crystal structure sample potential factors; and inputting the plurality of crystal structure target potential factors into a conditional diffusion model to obtain a target crystal structure corresponding to the powder X-ray diffraction experiment spectrum output by the conditional diffusion model, and the conditional diffusion model is obtained based on training of the crystal structure sample potential factors. According to the method, the crystal structure information can more purely and more accurately encode the core structure characteristics, and the success rate and the accuracy of analyzing the crystal structure from the complex atlas are remarkably improved, so that high precision and high robustness are obtained.

The invention belongs to the technical field of nuclear fuel element surface protection, and particularly relates to a multi-layer composite (Cr, Al) Nx / Cr protective coating for a nuclear reactor zirconium alloy cladding and a preparation method of the multi-layer composite (Cr, Al) Nx / Cr protective coating. The coating adopts a multi-layer structure design consisting of a buffer layer, a middle layer and an outermost layer in sequence from inside to outside, wherein the buffer layer is a Cr coating; the middle layer is a nitrogen-saturated (Cr, Al) Nx coating, x is larger than or equal to 1, the middle layer is of a columnar crystal structure, and the hardness of the middle layer is 5-10 GPa; the outermost layer is a non-stoichiometric ratio (Cr, Al) Nx coating, x is larger than or equal to 0.6 and smaller than or equal to 0.9, a nanocrystalline structure is shown, and the hardness is 12-25 GPa. Component regulation, hardness gradient and a microstructure are subjected to collaborative design, so that the coating has excellent wear resistance, high oxidation resistance and structural integrity at the same time under a harsh nuclear working condition, the safety margin of the zirconium alloy cladding under normal service and accident working conditions is greatly improved, and the service life of the zirconium alloy cladding under normal service and accident working conditions is greatly prolonged.

A method for producing calcium phosphate crystals according to the present invention comprises a step (S11) for preparing a weakly basic phosphoric acid solution containing a complex comprising a rare earth element ion and a coordination compound having a ligand coordinated to the rare earth element ion and a step (S12) for adding a calcium-containing compound to the weakly basic phosphoric acid solution and hydrolyzing. Some of the plurality of calcium ions contained in the structure of the calcium phosphate crystals are substituted by the rare earth element ion.

The invention relates to the technical field of functional polymer composite materials, in particular to an intermediate film for laminated glass based on color generation of a photonic crystal structure and a preparation method of the intermediate film. The intermediate film comprises a thermoplastic resin matrix and a three-dimensional photonic crystal structure region dispersed in the thermoplastic resin matrix, wherein the three-dimensional photonic crystal structure region is formed by self-assembly of monodisperse microspheres, and the central wavelength of a photonic forbidden band of the region is located in a visible light range. According to the invention, a three-dimensional photonic crystal structure is constructed in the intermediate film, and structural color generation is generated by utilizing selective reflection of the photonic band gap effect on visible light with a specific wavelength. According to the laminated glass, the color is generated by interference of light instead of absorption of chemical pigments, so that the color can be continuously and regularly changed along with the change of an observation angle or an incident light angle, the dynamic and changing visual aesthetic feeling is given to the laminated glass, and the higher requirements of the fields of modern buildings, automobiles and the like on dynamic aesthetics and personalized appearance are met.

An apparatus for implementing a microacoustic filter having an acoustically decoupled electrode structure is disclosed. In an example aspect, a device includes a microacoustic filter having a piezoelectric layer (126), a substrate (316), and an electrode structure (308-1, 308-2, 308-3, 308-4). The piezoelectric layer has a crystal structure for a lateral excitation plate mode. The electrode structure is positioned between the piezoelectric layer and the substrate and has a first surface (504-1) facing the piezoelectric layer. The microacoustic filter also includes at least one spacer (136-1, 136-2) extending from the substrate through a plane (508) defined by the first surface of the electrode structure and toward the piezoelectric layer to form a cavity (318) between the electrode structure and the piezoelectric layer.

The invention provides a multi-junction cascade photonic crystal surface emitting laser and a preparation method thereof. The multi-junction cascade photonic crystal surface emitting laser comprises a substrate; the three-dimensional photonic crystal structure is arranged on the substrate, the three-dimensional photonic crystal structure comprises a longitudinal periodic structure formed by a plurality of laminated structures which are sequentially stacked in the vertical direction of the substrate, each laminated structure comprises an active layer and a photonic crystal layer, and the photonic crystal layer provides optical feedback for the active layer to form optical resonance; a transverse periodic structure is formed in each photonic crystal layer; and the plurality of tunnel junctions are arranged between the two adjacent laminated structures and are used for electrically connecting the two adjacent laminated structures.

The invention relates to the technical field of gas adsorbents, in particular to an MOF-based gas adsorbent with a core-shell-shell structure as well as a preparation method and application of the MOF-based gas adsorbent. According to the MOF-based gas adsorbent disclosed by the invention, UiO-66 regulated and controlled by defect engineering is taken as a core layer, and the defect density in a UiO-66 crystal structure is accurately controlled by introducing a specific regulator glacial acetic acid, so that a sufficient physical adsorption space is provided for toluene molecules, and abundant acidic adsorption sites are formed; the PDA middle layer has dual functions of interface bonding and performance collaboration, so that the adsorption affinity of the material to toluene is further enhanced, and the adsorption performance is synergistically improved; the super-hydrophobic ZIF-8 is used as the outermost shell layer, on one hand, the super-hydrophobic ZIF-8 can be used as a molecular barrier to efficiently block external water molecules from entering the core layer UiO-66, the inactivation of core Zr active sites due to hydration is avoided, and the stability problem in a high-humidity environment is solved; and secondly, the diffusion behavior of toluene molecules can be regulated and controlled through a molecular sieving effect, so that high-selectivity and high-stability adsorption on toluene under a high-humidity condition is realized.