294results about How to "Short manufacturing cycle" patented technology

The invention discloses an ultra-high-temperature ceramic modified C / C composite material for aerospace power and a preparation method thereof. The oxidation ablation resistance of the C / C composite material is improved by introducing a ZrC and SiBCN multiphase ultra-high-temperature ceramic matrix into a C / C green body. The C / C-ZrC-SiBCN ultrahigh-temperature ceramic-based composite material is prepared by the following steps: carrying out high-temperature heat treatment on a carbon fiber preform, carrying out chemical vapor-phase oriented deposition on a carbon matrix process, carrying out densification by a high-pressure complex-phase precursor uniform mixing, dipping and co-cracking process, and carrying out post-high-temperature heat treatment until the material density reaches 2.3-2.5 g / cm < 3 >. The specific preparation method comprises the following steps: firstly, carrying out high-temperature heat treatment on a carbon fiber preform, then carrying out PyC interface deposition and matrix carbon preparation by adopting a chemical vapor deposition process, then preparing a ZrC ceramic matrix and a SiBCN matrix, and then carrying out post-high-temperature heat treatment on the formed composite material to obtain the ZrC / SiBCN composite material. Finally, SiC surface coating is conducted through chemical vapor deposition, and the C / C-ZrC-SiBCN ultrahigh-temperature ceramic-based composite material for aerospace power is obtained. The C / C-ZrC-SiBCN ultrahigh-temperature ceramic-based composite material has the advantages of being resistant to ultrahigh temperature, low in expansion coefficient, excellent in oxidation resistance and ablation performance and the like.

The medium-temperature radial forging method comprises the steps that pretreatment is conducted, specifically, a niobium-tungsten alloy extrusion bar blank is heated for 60-180 minutes at the temperature of 750-950 DEG C, rapid forging and straightening are conducted, and a medium-temperature radial forging bar blank is obtained and annealed for 60-120 minutes at the temperature of 1250-1450 DEG C; medium-temperature radial forging is conducted, specifically, a two-step method is adopted, in the first step, a bar blank is preheated to 80-100 DEG C and coated with Ta1350 high-temperature glass powder, heat preservation is conducted for 90-180 minutes at the temperature of 1050-1150 DEG C, and the bar blank is forged into a bar with the diameter of 70 + / -1 mm in the mode that the diameter is reduced by 7-10 mm every time; and in the second step, the heating and coating processes are repeated, the diameter is reduced by 5-7 mm every time, and the bar with the required specification is manufactured. By optimizing the medium-temperature forging and annealing process, the fine grain structure is controlled, the high-temperature mechanical property, creep resistance and oxidation resistance of the material are improved, and the material is suitable for aerospace engines and other high-temperature and high-pressure scenes. Compared with a traditional method, the technology improves the yield, shortens the production period, reduces the labor intensity, is suitable for large-scale production, reduces surface air suction, oxidation and burning loss, and improves the production efficiency and the finished product quality.

The invention discloses a preparation method of a TPMS structural ceramic membrane with high air permeability. The TPMS structural ceramic membrane is prepared by taking the ceramic slurry as a raw material and adopting photocuring 3D printing forming and high-temperature sintering. A digital model of a TPMS structural ceramic membrane is constructed on the basis of a three-period TPMS structure, the ceramic membrane is composed of a TPMS porous structure supporting body and a thickness-controllable separation layer, and the TPMS structural supporting body prepared through 3D printing remarkably reduces the permeation resistance of the ceramic membrane through high porosity and low pore channel tortuosity of the TPMS structural supporting body. The TPMS structural ceramic membrane is formed at a time through photocuring 3D printing and formed through one-time sintering, the preparation period is effectively shortened, and sintering energy consumption is reduced. The prepared TPMS structural ceramic membrane is high in air permeability, uniform and controllable in pore structure and good in stability in a high-temperature environment, and an efficient material is provided for high-temperature gas dust removal.

The invention provides a scoliosis orthopedic brace digital design method, medium and system, and belongs to the technical field of scoliosis orthopedic brace design, and the scoliosis orthopedic brace digital design method comprises the following steps: firstly, extracting a contour image of each shooting angle, and compressing the contour image into a two-dimensional matrix; inputting the contour matrixes into a pre-training model to obtain a corresponding three-dimensional contour matrix; the three-dimensional matrixes are traversed, a three-dimensional theoretical matrix of each angle is obtained after rotation according to the shooting angle, and similarity calculation is carried out on the three-dimensional theoretical matrix and the corresponding three-dimensional generation matrix; and selecting the three-dimensional generation matrix with the highest similarity as a candidate, and performing correction by using a difference regression function to obtain a final three-dimensional contour image. And finally, the algorithm inputs the three-dimensional contour image into a pre-trained scoliosis orthopedic brace parameter model, and outputs a three-dimensional model marked with information such as supporting points and pressure points as a scoliosis orthopedic design scheme. The problem that existing counting depends on experience of doctors, and misoperation is prone to occurring is solved.

The invention discloses a preparation method of silicon-based composite aerogel containing metal oxide, which comprises the following steps: by taking a silicon source such as silica sol or silicate ester and inorganic metal salt as reaction raw materials and an alcohol-water solution as a solvent, controlling hydrolysis and polycondensation of reactants by adjusting the pH value of a reaction solution, and obtaining double-phase / multi-phase sol only through one-step hydrolysis; the preparation process of the sol is simplified, the rapid preparation of the gel is realized by combining a microwave curing process, and the obtained gel is subjected to solvent replacement and drying to obtain the silicon-based composite aerogel containing the amorphous metal oxide. The silicon-based composite aerogel prepared by the invention has excellent high-temperature resistance, and still maintains an amorphous phase structure after being subjected to heat treatment for 30 minutes at 1000 DEG C, so that structural collapse caused by crystallization is avoided.

The invention provides a SiZrOC thermal insulation ceramic material and a preparation method thereof, and relates to the technical field of thermal insulation materials. The preparation method comprises the following steps: mixing a zirconium source solution and a silicon source solution to obtain a photosensitive solution; wherein the zirconium source solution contains carbon-carbon double bonds, and the silicon source solution contains sulfydryl and carbon-carbon double bonds; performing ultraviolet radiation on the photosensitive solution to enable carbon-carbon double bonds in the photosensitive solution to react with sulfydryl, and performing molding treatment to obtain a precursor blank; and carrying out heat treatment on the precursor blank to obtain the SiZrOC thermal insulation ceramic material. Under the action of ultraviolet light, a mercapto-alcohol click reaction can be induced to enable the photosensitive solution to be crosslinked and cured, and then C and groups and the like which cannot be maintained at high temperature are removed through heat treatment, so that the SiZrOC heat insulation ceramic material is obtained, long-time and complex aging and low-temperature heat treatment are not needed, the preparation period is greatly shortened, and the preparation cost is reduced. The preparation efficiency of the SiZrOC heat insulation ceramic material is improved.

The invention discloses a movie and television play intelligent shrinking method based on a large model, and the method comprises the steps: S1, carrying out the division processing of a movie and television play video and a plot introduction document, completing the segment division of the movie and television play video, and the plot paragraph division of the plot introduction document; s2, completing matching between the video clip and the plot paragraph by using a large language model; s3, generating a reduced script according to the plot introduction document by using a large language model; s4, the big language model completes the selection of the video clip in the step S1 based on the reduced script obtained in the step S3 and the matching relationship between the plot paragraph and the video clip obtained in the step S2; and S5, performing cross-modal retrieval in the range of the video clip selected in the step S4 by using the reduced story plot content to obtain a video picture. By intelligently generating the reduced script, the automatic editing process is realized, the manual operation is reduced, and the editing efficiency is improved.

The invention discloses a mesophase pitch carbon matrix modified high-thermal-conductivity C / SiC composite material and a preparation method thereof, the material is subjected to high-thermal-conductivity matrix modification through mesophase pitch melt impregnation, in-situ mesophase inversion and in-situ carbonization, and mesophase pitch carbon fibers are combined as a reinforcement, so that the high-thermal-conductivity C / SiC composite material is obtained. The mesophase pitch carbon matrix modified high-thermal-conductivity C / SiC composite material is obtained by densifying a silicon carbide matrix by adopting a polycarbosilane melt impregnation and in-situ cracking process, has excellent mechanical and high-thermal-conductivity properties, can be widely applied to the front edge, the end head and other parts of a hypersonic aircraft, and can effectively improve the use temperature and the service environment of the material. Meanwhile, the preparation process is simple, the equipment use requirement is low, and the material preparation process period and cost can be correspondingly reduced.

The invention discloses shell-imitated mechanically-enhanced photonic crystal paper, a preparation method thereof and application of the shell-imitated mechanically-enhanced photonic crystal paper in repeatable printing. The photonic crystal paper is prepared from a zirconium phosphate layered material and soft gel through blade coating shear force induced self-assembly alternate arrangement. The photonic crystal paper disclosed by the invention has a shell-imitated brick mud structure, and meanwhile, zirconium phosphate and soft gel have a strong hydrogen-bond interaction, so that the photonic crystal paper has high tensile strength, high flexibility, high modulus and self-supporting property, and can support repeated printing. When an aqueous solution containing a hygroscopic solute is used as ink to carry out ink-jet printing on the photonic crystal paper, the gel matrix is swelled, the lattice spacing is increased, and a lasting multi-color printing effect is achieved. The selected zirconium phosphate layered material has good thermal stability, and meanwhile, the brick mud structure can reduce the oxygen transmittance, so that the photonic crystal paper has flame retardant property, and the storage safety is improved. The blade coating method is simple and rapid, so that continuous production of the photonic crystal paper can be realized.

The invention discloses a polyimide hot-melt prepreg, a composite material and a preparation method of the polyimide hot-melt prepreg and the composite material, and belongs to the technical field of composite materials. The preparation method comprises the following steps: preparing a polyimide resin solution for impregnating fibers and self-adhering a surface layer from polyimide, a single solvent and a mixed solvent; preparing semi-solid polyimide prepreg for fiber impregnation and surface layer self-adhesion based on the two polyimide resin solutions, and then preparing an adhesive film and sequentially compounding with fiber cloth to obtain a fiber prepreg; and preparing the polyimide hot-melt prepreg based on the fiber prepreg. According to the preparation method disclosed by the invention, the reinforced fibers are fully infiltrated, and then the toughened and tackified resin layer is compounded on the surfaces of the impregnated reinforced fibers, so that the polyimide hot-melt prepreg with controllable resin content and good paving adhesiveness is obtained, and therefore, the low-porosity high-quality fiber reinforced composite material is prepared, the control difficulty of a forming process is greatly reduced, and the production efficiency is improved. The production efficiency is improved.

The invention belongs to the technical field of building materials, and particularly relates to a bentonite-starch composite thixotropic agent as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) grafting a carbon-carbon double bond on starch to obtain grafted modified starch; (2) grafting ether groups on carbon-carbon double bonds of starch to obtain modified etherified starch; (3) adsorbing a polycarboxylate superplasticizer and polyethylene glycol on the surface and between layers of bentonite to obtain modified bentonite; and (4) adding the modified etherified starch, the modified bentonite, a cross-linking agent, an initiator and a pH regulator into water, and carrying out graft copolymerization reaction to obtain the bentonite-starch composite thixotropic agent. The composite thixotropic agent has excellent thixotropic performance, stability, plasticity and cohesiveness, and overcomes the defects that bentonite has water absorption expansibility and is difficult to store, and an organic thixotropic agent is high in price and poor in stability.

The invention belongs to the technical field of biological medicine, and particularly relates to sterile cefepime hydrochloride and a direct preparation method thereof. The method comprises the following steps: firstly, carrying out condensation reaction on a 7-MPCA solution and an AE active ester solution through a solid base catalyst column at the same time; then, carrying out extraction phase separation, two times of pH regulation crystallization, activated carbon decoloration and sodium sulfite reduction on the condensation liquid to obtain a cefepime hydrochloride liquid to be crystallized; and then taking a part of the cefepime hydrochloride to-be-crystallized liquid to prepare a seed crystal mixed liquid, and adding the rest of the cefepime hydrochloride to-be-crystallized liquid and the crystallization solvent into the seed crystal mixed liquid at a specific speed to obtain the sterile cefepime hydrochloride. According to the method disclosed by the invention, the continuous production of the sterile cefepime hydrochloride is realized, the preparation period of the sterile cefepime hydrochloride is greatly shortened, side reactions and product degradation are reduced, the quality and yield of the obtained cefepime hydrochloride product are relatively high and stable, and industrial production is facilitated.

The invention relates to the technical field of molecular optoelectronic devices, and particularly discloses a tunable polarization photon source based on perovskite quantum dots and a preparation method thereof, and the method comprises the following steps: transferring a graphene-PMMA structure to the surface of a silicon wafer, and marking a pattern; manufacturing an outer lead electrode on the graphene according to the pattern; manufacturing a graphene electrode pair; and preparing chiral molecules with adjustable chirality: condensing the chiral molecules and graphene electrode amide, then adding a perovskite quantum dot precursor solution for reaction, and assembling quantum dots between the graphene electrode pairs in situ to obtain the tunable polarized photon source. According to the graphene electrode single-molecule device based on the dotted line etching method, a circularly polarized photon source is constructed, and quantum dots with high quality and controllable morphology are constructed by connecting chiral molecules to the edge of a graphene electrode and introducing chiral sites to assemble the quantum dots in situ; the molecular connection success rate is greatly improved; meanwhile, the molecular connection period is shortened.

The invention provides an engineering investigation report automatic generation system and method based on a BERT model. The system comprises a data preprocessing module, a BERT model optimization customization module, an information extraction and structuring module and a report generation engine. According to the method, the limitation that time and labor are consumed and errors are prone to occurring in the traditional report compiling process can be overcome, the engineering investigation data can be automatically analyzed and processed by integrating an advanced BERT model for optimization and customization, then a high-quality report meeting the industry standard and the customer requirement is generated, and intelligent processing of the engineering investigation data and automatic report compiling are achieved.

The invention relates to a titanium-aluminum composite material and a preparation method and application thereof, and the preparation method comprises the following steps: ball-milling and mixing titanium powder and aluminum powder, sequentially carrying out die filling, sheath welding and hot isostatic pressing treatment, and then sequentially carrying out sheath removal and machining to obtain the titanium-aluminum composite material, the diameter of the titanium-aluminum composite material ranges from 250 mm to 350 mm, and the thickness of the titanium-aluminum composite material ranges from 450 mm to 550 mm. The titanium powder and the aluminum powder are uniformly mixed through ball-milling mixing, the material is subjected to hot isostatic pressing forming through the sheath, the cost is low, the density improvement effect is remarkable, the large-size titanium-aluminum composite material can be prepared through hot isostatic pressing, batch production of the material is facilitated, the preparation period is greatly shortened, and the production cost is reduced. The problems that titanium-aluminum composite material particles are prone to agglomeration, difficult to form, low in density and uneven in structure are solved.

The invention provides a method and a system for converting a patent text into a video based on an AI technology. The method comprises the following steps: acquiring patent technology information and information used for generating copywriting keywords; generating picture information according to the patent technology information, generating copywriting information and audio information according to the information used for generating copywriting keywords, and synthesizing the picture information, the copywriting information and the audio information to obtain video information; and according to the generated picture information, copywriting information, audio information and video information, adjusting patent technology information and / or information used for generating copywriting keywords, and repeating the previous step until video conversion of the patent technology is completed. According to the patent technology information provided by the user, the keywords in the patent technology information can be extracted to automatically generate professional and accurate video content, the video production period is greatly shortened, meanwhile, the user can visually know the technology content, conversion of scientific and technological achievements is facilitated, and the patent technology is better promoted and popularized.

The invention relates to an inner cylinder casting forming method which comprises the steps that a casting sand core is divided into at least four layers for independent 3D printing, the first layer is a bed mould core (110), the second layer is a vertical pipe outer contour core (120), the third layer is an inner cylinder outer contour core (130), and the fourth layer is a cover core (140), so that an outer contour structure of a casting is formed; for an inner cavity structure of a casting, two vertical pipe cores (210) and a tire hanging core (220) are designed and printed, the tire hanging core (220) is further split into a tire hanging core main body (221) and four cores (222), and the four cores (222) are areas with high sand burning risk on the tire hanging core (220) and are formed by printing chromium ore materials. According to the scheme, the application range of the sand core 3D printing technology in the casting field can be expanded, and particularly the effective application of the sand core 3D printing technology on large-size and complex-structure products such as inner cylinders can be achieved.

The invention relates to the field of medical instruments, in particular to a detachable soft rubber structure for a puncture outfit, which comprises a sealing cover, a self-adjusting sealing cap, a choke valve and a puncture cannula, the self-adjusting sealing cap is arranged above the choke valve, the choke valve is arranged in a top opening of the puncture cannula, the choke valve and the puncture cannula are made of soft rubber materials, and the sealing cover is detachably connected with the puncture cannula. A through hole is formed in the top of the sealing cover, a clamping groove is formed in the outer wall of the top of the puncture cannula, an opening is formed in the clamping groove, the clamping groove is gradually narrowed from the opening in the closing direction of the sealing cover, a buckle matched with the clamping groove of the puncture cannula is arranged on the inner wall of the lower end of the sealing cover, and the sealing cover and the puncture cannula are rotationally clamped and connected through mutual matching of the clamping groove and the buckle. The connecting reliability and the sealing performance are guaranteed, the assembling technology is simplified and rapid, and convenience and elasticity of taking out other specimens in an emergency in an operation are achieved.

The present invention relates to a dental implant guide plate based on 3D printing, comprising a base and a guide hole, wherein the base comprises a positioning part for opening the guide hole, and a fixing part integrally connected to the lower end of the positioning part, wherein a planting point sleeve is arranged in the guide hole, a notch is arranged on the guide hole, and an adapter block matching the notch is arranged on the planting point sleeve, and the planting point sleeve is fastened in the guide hole, and in the process of drilling a bone hole inside the gum through the guide hole using a medical drilling tool, the drill bit displacement is avoided, and the positioning accuracy of the dental implant guide plate is improved; a method for a dental implant guide plate based on 3D printing is also disclosed, comprising the steps of: making a plaster model; reconstructing a three-dimensional model of teeth and bones in the oral and maxillary region of a patient; obtaining three-dimensional model data of the dental implant guide plate; and printing the dental implant guide plate. The present invention adopts 3D printing technology to shorten the production cycle of the entire reconfigurable guide plate, and realizes the rapid production of the base plate and the on-site reconstruction of the guide plate.

The invention belongs to the technical field of catalytic materials, and particularly relates to a macro-micro-nano integrated structured titanium silicalite molecular sieve catalyst as well as a preparation method and application thereof. According to the catalyst, SiC whiskers are grown on the surface of a 3D communicating hole SiC carrier in situ, TS-1 titanium silicalite molecular sieve precursor coating is combined with a steam crystal transformation process, and a TS-1 titanium silicalite molecular sieve coating with framework nickel doping and open mesopores is grown on the surface of the SiC whiskers, so that the loading capacity and catalytic activity of the titanium silicalite molecular sieve are effectively improved; meanwhile, excellent interface bonding force and a continuous heat conduction channel are provided through the SiC whiskers, and the heat transfer performance is enhanced. Compared with a traditional coating, the coating of the catalyst is rougher, and fluid turbulence and mass transfer efficiency are enhanced. According to the structured titanium silicalite molecular sieve catalyst, the utilization efficiency, the reaction rate and the selectivity of the catalyst are remarkably improved through coupling of macroscopic channels, micron pore channels and nano mesopores, and the structured titanium silicalite molecular sieve catalyst is particularly suitable for phenol hydroxylation reaction and olefin oxidation reaction.

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 straw feed microbial agent and application of the straw feed microbial agent in preparation of feed through straw fermentation, and belongs to the technical field of agricultural solid waste treatment. By optimizing the composition of phanerochaete chrysosporium, lactobacillus reuteri, lactobacillus paracasei, bacillus subtilis and bacillus cereus in the flora preparation, the obtained wheat straw microbial agent has the advantages that compared with the conventional straw yellow silage feed in the application of fermenting wheat to prepare feed, the yield of the wheat straw microbial agent is increased; according to the method, the content of crude protein is increased by 28.79%, the content of acetic acid is increased by 42.67%, the content of propionic acid is increased by 28.31%, the content of lactic acid is increased by 103.15%, the content of phosphorus element is increased by 33.19%, the content of calcium element is increased by 34.30%, the palatability and nutritional value of the straw feed are remarkably improved, and the method has the advantages of being low in cost, easy and convenient to operate, capable of shortening the preparation period of the wheat straw feed and the like.

The present invention discloses a magnetic levitation centrifugal compressor, which belongs to the field of compressor equipment, including a magnetic levitation motor assembly, wherein an interpolar cooling device is connected between a primary volute and a secondary volute at both ends of the magnetic levitation motor assembly through a first air pipe and a second air pipe; the air inlet diameter of the first air pipe is the same as the air outlet diameter of the second air pipe. The air inlet diameter of the first air pipe and the air outlet diameter of the second air pipe are the same or as close as possible to minimize noise reduction, and the interpolar cooling device of the first air pipe and the second air pipe can cool the air compressed for the first time, which can effectively reduce the temperature of the compressed air, thereby reducing the pressure of the gas flowing into the second air pipe, and can also effectively reduce the pressure difference between the intake air pressure and the exhaust air pressure, which is beneficial to noise reduction. In addition, the present invention has lower energy consumption, high air filtration accuracy, and a balanced structure of the internal rotating shaft of the compressor, which can reach a higher rotation speed, and better gas compression effect and product quality.

The invention provides a method for preparing super-hydrophobic silicon dioxide aerogel by using a combined modifier. The method comprises the following steps: S1, mixing silane, ethanol and deionized water, adding a catalyst, and uniformly stirring to obtain a precursor solution A; s2, sequentially adding a combined modifier into the precursor solution A, and uniformly stirring to obtain a mixed solution B; s3, the mixed solution B is poured into a mold for standing, and wet gel is obtained; s4, carrying out replacement aging treatment on the wet gel to obtain alcogel; and S5, carrying out drying treatment on the alcogel by adopting a supercritical carbon dioxide drying technology to obtain the super-hydrophobic silicon dioxide aerogel material. The preparation process is greatly simplified, the preparation period is shortened, and the consistency of product quality is improved. And compared with the existing production process, the preparation method is more environment-friendly and energy-saving, and is more environment-friendly. The application field of the super-hydrophobic aerogel material can be expanded, and remarkable economic and social benefits are brought.

The invention relates to the technical field of solid waste resource utilization, in particular to a geopolymer material prepared by using red mud as a raw material and a method, the red mud is calcined and then added with ardealite, coal-fired slag, coal gangue and the like to construct a geopolymer material composition system, and the geopolymer material is prepared by adding an exciting agent and grinding. According to the geopolymer material disclosed by the invention, the overall activity of the composition system is excited by adding the phosphogypsum, the coal gangue, the solid alkali red mud and the exciting agent, and the dosage control of the coal-fired slag, the phosphogypsum, the coal gangue, the solid alkali red mud and the exciting agent is combined, so that the activity index (28d) of the geopolymer material reaches 95% or above, the internal illumination index is reduced to 0.6 or below, the external illumination index is reduced to 0.8 or below, and the application safety of the geopolymer material is enhanced.

The invention relates to low-density aerogel with underwater elasticity as well as a normal-pressure atmospheric drying preparation method and application thereof, and belongs to the technical field of aerogel preparation methods. The invention provides a low-density aerogel with underwater elasticity and a normal-pressure atmospheric drying preparation method thereof in order to solve the problem that when the low-density aerogel is prepared through normal-pressure drying, the structure collapses easily. The low-density aerogel has a double-nanofiber skeleton composed of oxidized cellulose nanofibers and silicon dioxide nanofibers and is prepared by adopting a normal-pressure atmospheric drying method. Before and after the aerogel is dried, the volume shrinkage rate is 8.37 + / -1.62%, and the density is only 10.86 + / -0.32 mg cm <-3 >; the porosity is gt; according to the present invention, the maximum compressive strain of the material can reach 117.65 kPa when the air impact compressive strain is 80%, and the maximum compressive strain of the material can reach 13.26 kPa when the water compressive strain is 80%, such that the excellent underwater elastic property and the excellent shape memory property can be provided.

The invention provides a method for preparing a lithium iron manganese phosphate composite positive electrode material based on a sol-gel method, and belongs to the technical field of lithium ion battery positive electrode materials. The method comprises the following steps: respectively preheating raw material solutions to a preset temperature; the method comprises the following steps: uniformly mixing a manganese salt solution with a complexing agent solution, adding a ferrite solution, a phosphorus-containing compound solution and a lithium salt solution, and dropwise adding concentrated ammonia water to obtain a reaction solution; placing the reaction solution in an ultrasonic-microwave combined reaction system, and performing ultrasonic treatment, ultrasonic-microwave cooperative treatment and microwave treatment to obtain xerogel; performing thermal decomposition treatment, adding a carbon source into a cooled product, and performing grinding and demagnetizing treatment to obtain precursor powder; and carrying out microwave gradient high-temperature sintering on the precursor powder in a microwave reaction system under a protective atmosphere condition, and cooling to obtain the lithium iron manganese phosphate composite positive electrode material. According to the invention, the preparation period is shortened, the uniformity of the material is effectively improved, and the prepared positive electrode material shows excellent dispersity, electronic conductivity and stability.

The invention relates to the field of wind power generation equipment manufacturing, and discloses a wind turbine generator blade and a preparation method thereof. According to the method, a shell blade root prefabricated part, oblique angle cloth and an outer skin are sequentially laid on a shell mold, then a rear edge beam, a carbon fiber girder and a core material are laid, polyurethane resin is poured through a vacuum pouring method to form a blade shell, a carbon fiber web is installed, and the wind turbine generator blade is formed after mold closing and glue scraping. The method has the advantages of overall rapid forming and short manufacturing period; the girders and the webs are prefabricated and formed by adopting carbon fiber prepreg, so that the overall strength and rigidity of the blade are improved, and the weight is reduced. The wind turbine generator blade prepared by the method has better strength and rigidity and lighter weight, and is beneficial to actual use.

The invention discloses a golden finger manufacturing method and a PCB, and the method comprises the steps: providing a substrate which is provided with a circuit layer, and the circuit layer at least comprises a bonding pad or a hole exposed out of the surface of the substrate; pasting a conductive film on the surface of the substrate so as to enable the conductive film to be connected with a bonding pad or a hole on the surface of the substrate; windowing the surface of the conductive film to remove the conductive film on the surface of the golden finger area; connecting an electroplating power supply to the conductive film so as to plate gold on the golden finger area; and removing the conductive film. By adopting the golden finger manufacturing method, the problem of copper leakage and nickel gold suspension caused by lead etching can be solved, the technological process can be shortened, and the problem of copper surface glue dirt can be solved.

The application discloses a method for preparing silicon carbide ceramic fibers by combining sol-gel and dry spinning. The method comprises the following steps: 1) after preparing a second silicon-based sol, a spinning aid is added to prepare a spinnable silicon-based sol; 2) the spinnable silicon-based sol is prepared into fiber filaments by using a dry spinning process; 3) the fiber filaments are cracked into silicon-carbon-oxygen fibers; and 4) the silicon-carbon-oxygen fibers are sintered into silicon carbide ceramic fibers. The method is different from a mainstream polycarbosilane precursor method for preparing silicon carbide ceramic fibers, does not need a non-melting treatment process, has the advantages of adjustable composition, low raw material cost and simple process and the like, and has important significance for low-cost preparation of silicon carbide ceramic fibers.