32results about How to "Excellent superconductivity" patented technology

The invention relates to a method for improving a critical current for continuously preparing a YBCO (Yttrium Barium Copper Oxide) strip, which comprises the following steps of: (1) in a vacuum chamber of equipment for continuously preparing a YBCO superconducting layer, fixing a metal substrate on a guide belt; (2) using YBCO as a target material, wherein the target-substrate distance is in the range of 40 to 60mm; (3) regulating a laser optical path before vacuumizing; (4) when the vacuum degree in the vacuum chamber is superior to 3*10<-4>Pa, heating the metal substrate to the temperature of 750 to 770 DEG C and controlling the pure oxygen atmosphere into 20 to 30Pa; (5) depositing a first layer of YBCO thin film under the laser frequency of 10 to 20Hz and at the traveling speed of 0.1 to 0.4mm / s, then depositing a plurality of layers of YBCO thin films, and when depositing the next layer of YBCO thin film every time, respectively rising the temperature of the metal substrate in the process of depositing the previous layer of YBCO thin film by 10 to 20 DEG C and depositing the next layer of YBCO thin film under the laser frequency of 10 to 40 Hz and at the traveling speed of 0.1 to 0.2mm / s; and (6) carrying out in-situ annealing to prepare the YBCO superconducting layer. According to the invention, the layered deposition is adopted, the temperature is properly risen between the layers, the problem of variation of a cube texture of the YBCO layer along with the increase of the thickness is solved, and the superconducting performance is effectively improved.

The invention discloses a method of preparing a Tl-1223 superconductive thin film. In the invention, a thallium-containing amorphous precursor film and a thallium-containing sintering accompanying target are sealed and coated with a silver foil or a gold foil, and then sintering is carried out in a sealed argon gas or a flowing oxygen environment. In the method, phase forming temperature zone of low-temperature phases, such as Tl-1212 and Tl-2212, can be crossed quickly and Tl-1223 superconductive phase temperature zone is directly reached, thus producing a pure-phase thin film. The method isshort in temperature increase / decrease time and constant temperature time and is low in production cost.

Provided is a superconducting cable with aluminum cryostat configured to improve superconductivity by increasing reflectivity of cryostats and enhancing cooling performance. The superconducting cable includes: a core provided with a conductor; and a cryostat surrounding a periphery of the core. A material of the cryostat is aluminum or an aluminum alloy and a surface roughness of the cryostat is 30 microns or less in terms of RMS value.

A method for producing a YBCO superconducting layer thick film on a metal baseband substrate comprises the following steps: 1, adopting a metal baseband with an isolating layer as a sample substrate; 2, adopting YBCO as a target material, and controlling the target-substrate distance to be 40-60mm; 3, carrying out vacuum pumping until the vacuum degree in a vacuum cavity is better than 3*10<-4>Pa, heating the metal baseband substrate to 750-770DEG C, and keeping the temperature unchanged; 3, introducing oxygen to the vacuum cavity, controlling the pressure of pure oxygen atmosphere to be 20-30Pa, and keeping the pressure; 4, producing the YBCO film on the metal baseband substrate with the isolating layer through using a pulsed laser deposition (PLD) technology, depositing the YBCO film at a laser frequency of 10-20Hz, heating the metal baseband substrate to make the temperature be 5-10DEG C higher than an original temperature, keeping the temperature, continuously depositing the YBCO film under same conditions after the temperature is stable, and changing a traditional continuous deposition mode to an intermittent deposition mode; and 5, carrying out in situ annealing on the deposited YBCO films in order to produce the YBCO superconducting layer thick film on the metal baseband substrate with an isolating layer. The YBCO film produced by using the above laser method has the advantages of good texture, good surface morphology and high electric performance.

The invention discloses a graphene catalyst applied to improve ionic conductivity of a lithium polymer battery. The graphene catalyst is prepared by the following steps of: (1) material selection, (2) preparation of diamine POSS (polyhedral oligomeric silsesquioxane), (3) preparation of octaphenyl POSS, (4) preparation of graphite oxide and (5) preparation of the graphene catalyst. The catalyst effectively improves the capacity of the battery and a working platform, can effectively avoid passivation of Li ions on an electrode to form an oxide, and prolongs a service life of the battery; the internal resistance is reduced greatly, so that an internal heating phenomenon of the battery is reduced; when a problem appears in the battery, the problem can be embodied timely and appears as ballooning without explosion; the safety and stability of the battery are improved; and at the same time, the graphene catalyst has excellent performances such as superconductivity, mechanical properties and heat resistance.

The invention discloses a method for preparing a YBCO (yttrium barium copper oxide) film by taking ethanol as a solvent through a low-fluorine MOD (metal organic deposition) method, and belongs to the technical field of materials. The method comprises the following steps: (1) dissolving yttrium acetate and barium trifluoroacetate in water to prepare a yttrium barium solution, boiling and concentrating; (2) adding ethanol, boiling and concentrating; (3) repeating the step (2) for 4-6 times to prepare a yttrium barium ethanol solution; (4) dissolving copper isocaprylate in ethanol to prepare a copper ethanol solution; (5) mixing the copper ethanol solution with the yttrium barium ethanol solution, filtering, reheating and concentrating to prepare a precursor solution; (6) applying the precursor solution to a substrate by spin coating, pyrolyzing and crystallizing. The method has the advantages of low environmental pollution, high production efficiency and the like, and has a good application prospect.

Disclosed is a magnesium diffusion preparation method for a magnesium diboride superconducting wire rod based on MgB<4> precursor powder. The preparation method is based on a center magnesium diffusion technology; and MgB<4> is used as the precursor powder to replace the conventional boron precursor powder. The preparation method mainly comprises the steps of 1, performing ball milling and uniform mixing on original powder, then pressing the mixed powder into circular sheets by a powder compressing machine, and finally performing vacuum sintering and crushing on the circular sheets to obtain MgB<4> powder; and 2, fixing a magnesium rod in the center of a metal tube, filling the space between the magnesium rod and the metal tube with the MgB<4> powder, sealing the two ends of the tube, and then carrying out rotary calcining, pulling and drawing and vacuum thermal processing to obtain a MgB<2> wire rod. The MgB<2> wire rod superconducting core prepared by the preparation method is high in density; and meanwhile, the MgB<2> wire rod has high critical current density, superconducting phase filling rate and engineering critical current density, and excellent superconducting performance in medium and high magnetic fields.

The invention relates to a method for manufacturing a large-scale MgB2 single-core superconducting wire. According to the method, Mg powder and B powder are used as raw materials, a low-carbon steel pipe with a certain specification is cleaned, the Mg powder and the B powder are placed in a ball-milling tank in a glove box filled with argon according to a molar ratio of 1.1:2, a certain number of mill balls are added for ball milling, the cleaned low-carbon steel pipe is then filled with the evenly mixed raw powder, vibration is conducted with a vibration device and the raw powder is compacted with a tamper, the opening is sealed, and then a wire with Mg and B mix powder wrapped in low-carbon steel with a certain diameter and length is obtained through rotary swaging, drawing and intermediate annealing; the MgB2 single-core superconducting wire can be obtained after the wire is sintered under 800 DEG C - 900 DEG C for 10 min - 20 min. Large-scale MgB2 single-core superconducting wires with diameters ranging from 0.95 mm to 1.05 mm and lengths of 1000 m can be manufactured with the method, and the wires have a good electrical property and mechanical property.

The invention discloses a preparation method of a FeSe-based superconducting wire. The method comprises the following steps: 1, assembling an iron tube, an iron rod and an iron plug to obtain a tubingcomplex; 2, sealing the two ends of the tubing complex, and then obtaining a single-core FeSe-based wire through rotary swaging and drawing in sequence; 3, sintering the single-core FeSe-based wire to obtain a FeSe-based wire; and 4, annealing the FeSe-based wire to obtain a FeSe-based superconducting wire. According to the invention, the single-core FeSe-based wire is formed through powder charging by adopting a vibration tubing method and cold processing, and the iron rod diffuses into the molten Se powder in the subsequent sintering process to generate a compact FeSe layer and form a central hole, so that the intergranular connectivity is improved; and the oxidizing atmosphere is introduced through the central hole to be in full contact with the FeSe-based superconducting phase for annealing, so that the precipitation of interstitial iron is promoted, the superconductivity of the FeSe-based superconducting wire is improved, and the current-carrying performance of the FeSe-based superconducting wire is further improved.

The invention relates to a glycine-doped MgB2 superconductor with high critical current density and a preparation method thereof. The preparation method of the glycine-doped MgB2 superconductor includes fully mixing Mg powder, B powder and glycine particles, and obtaining mixed powder of MgB2+Gly of 2-8%; pressing the mixed powder into cylindrical slices under the pressure of 2-10MPa, and placingthe slices in a high-temperature differential scanning calorimeter or a pipe-shaped sintering furnace to carry out sintering; continuously heating at a heating rate of 5-20 DEG C / min to 750-850 DEG C, sintering and keeping warm for 0.5-1h, and cooling to the room temperature at a cooling speed of 30-40 DEG C / min. On the premise that the superconducting transition temperature Tc is not reduced to the greatest extent, novel carbon-containing compound glycine doping is adopted to achieve C replacement effect, and the high-performance MgB2 superconductor is obtained. The shortcoming that traditional C doping reduces the critical current density under a low field is overcome, the critical current density is improved under the whole magnetic field, and a superconductor with superior superconductivity is obtained.

The invention discloses a rapid sintering preparation method of Tl-2212 superconducting thin film. Silver foil or gold foil is used to seal and wrap the amorphous precursor film containing thallium and the burning target containing thallium, and the Sintering in the environment. The invention includes four processes including the preparation of a precursor film, the preparation of a thallium source accompanying firing target, the rapid temperature-raising sintering of the precursor film in an argon / oxygen environment, and the oxygen-supplementing heat treatment of a primary sample. Compared with the traditional sintering method, the sintering conditions for growing Tl‑2212 thin films using this technology are not affected by the deposition method of the precursor film, the powder particle size of the starting material of the thallium source accompanying firing target and its preparation method, avoiding the Due to the replacement of the manufacturer's raw materials and the pioneering film deposition method, it is necessary to re-explore the sintering process for a long time. At the same time, the method also greatly reduces the amount of the thallium source accompanying the burning target, shortens the heating and cooling time and constant temperature time, reduces the production cost, and improves the repeatability of the experiment.

The invention relates to a foam base material for an anti-millimeter wave radar camouflage net and a processing technology of the foam base material, and belongs to the technical field of camouflage nets. The foam material is prepared by the steps: mixing the following components: 60-80 parts by mass of polyethylene or polypropylene or polyolefin, 1-10 parts by mass of modified carbon nanotubes, 1-5 parts by mass of modified graphene, 1-5 parts by mass of rare earth, 1-10 parts by mass of a flame retardant, 1-10 parts by mass of a foaming agent, 2-20 parts by mass of a sensitizing agent and 2-5 parts by mass of an antioxidant, and then sequentially performing extrusion, irradiation and high-temperature foaming; and finally, pressing small rice grains on the single surface or double surfaces of a sheet. According to the invention, the prepared foam base material is provided with the small rice grains, so that the absorption and shielding effects on the millimeter-wave radar at a high frequency band can be realized.

The invention discloses a method for preparing a YBCO (yttrium barium copper oxide) film by taking ethanol as a solvent through a low-fluorine MOD (metal organic deposition) method, and belongs to the technical field of materials. The method comprises the following steps: (1) dissolving yttrium acetate and barium trifluoroacetate in water to prepare a yttrium barium solution, boiling and concentrating; (2) adding ethanol, boiling and concentrating; (3) repeating the step (2) for 4-6 times to prepare a yttrium barium ethanol solution; (4) dissolving copper isocaprylate in ethanol to prepare a copper ethanol solution; (5) mixing the copper ethanol solution with the yttrium barium ethanol solution, filtering, reheating and concentrating to prepare a precursor solution; (6) applying the precursor solution to a substrate by spin coating, pyrolyzing and crystallizing. The method has the advantages of low environmental pollution, high production efficiency and the like, and has a good application prospect.

The invention discloses a superconductor cold pressing connecting method, relates to a superconductor connecting method, and belongs to the technical field of superconductor connecting. The superconductor cold pressing connecting method solves the problems that a high-temperature superconducting material obtained according to an existing welding method is low in strength and the superconducting performance is reduced. The superconductor cold pressing connecting method comprises the first step of rubbing down and polishing the end faces of two circular-bar-shaped superconductors, the second step of processing superconductor powder into a cake shape, and the third step of carrying out welding in an ice pressure welding mode. The superconductor cold pressing connecting method is used for connecting the superconductors.

The invention provides a semiconductive rubber, a preparation method and application thereof. The semiconductive rubber of the present invention has a volume resistivity of ≤500Ω·cm and a Shore A hardness of ≤75, and the raw material for the semiconductive rubber contains superconductive carbon black. In order to obtain low hardness technical indicators, in formula design, the amount of reinforcing agent is usually reduced, such as reducing the amount of carbon black. However, the reduction of the amount of carbon black will not only reduce the mechanical properties and aging properties of the rubber, but also increase the volume resistivity of the rubber, thus failing to meet the performance requirements of semi-conductivity. To solve this problem, the present invention uses superconducting carbon black with large specific surface area and superconducting properties. Due to its large specific surface area, superconducting carbon black has good reinforcing effect and excellent electrical conductivity. Even if it is added in a small amount, it can make the mechanical and electrical properties of rubber meet the requirements.

The invention relates to a metal Sn doped MgB2 superconductor and a high-temperature rapid preparation method thereof. A structural formula of the superconductor is (Mg1.02B2)1-xSnx, wherein x=0.01-0.05. The method comprises the following steps: fully mixing Mg powder, B powder and Sn powder according to atomic ratio, pressing and preparing the mixture into a cylindrical flake under the pressure of 2 to 10 MPa, and then putting the cylindrical flake into a high temperature differential scanning calorimeter or a tubular sintering furnace for sintering; and continuously heating the cylindrical flake to 850 to 900 DEG C at heating rate of 5 to 20 DEG C per minute for sintering treatment, and cooling the cylindrical flake to room temperature at cooling rate of 30 to 40 DEG C per minute. The practical application field of MgB2 is in an around 3T magnetic field, so the method improves the superconductivity of the MgB2 superconductor in a short time by doping metal Sn and using a high-temperature sintering method. The preparation method is simple, has low cost of the raw materials and short preparation time, and is a quite potential research method; and simultaneously, the obtained superconductor has obvious superconductivity.

The invention discloses a graphene composite material and a preparation method thereof. The graphene composite material is prepared from the following components in parts by weight: 50 parts by weight of graphene, 25 to 29 parts by weight of polycarbonate, 5 to 9 parts by weight of 1-ethyl-3-methylimidazoleonium tetrafluoroborate, 32 to 36 parts by weight of nickel sulfate, 2 to 6 parts by weight of acetonitrile, 38 to 42 parts by weight of polyvinyl alcohol, 7 to 9 parts by weight of cellulose grafted acrylamide polymer, 16 to 22 parts by weight of starch-polyacrylate grafted copolymer, 7 to 9 parts by weight of polyacrylic acid-acrylonitrile, 20 to 24 parts by weight of potassium permanganate, 3 to 5 parts by weight of tungsten carbide and 4 to 6 parts by weight of high-strength carbon fibers. The preparation method disclosed by the invention has the advantages of high yield, no pollution and uniform graphitization; in addition, the graphitization degree is improved; the graphene composite material has the characteristics of excellent superconducting electrical properties, heat dissipation performance, superhigh toughness, light weight, high-temperature resistance, flame-retardant property, anti-oxidation property, acid and alkali resistance, mechanical damage resistance and the like.

The invention belongs to the field of preparation of high-temperature superconducting materials and particularly relates to a preparation method and application of high-volatility complex ligand barium precursor salt. After anhydrous beta-barium diketone precursor salt (Ba(tmhd)2) is prepared by being reacted with 2,2,6,6-tetramethyl-3,5-heptadione and taking barium as a raw material, a barium salt reaction system is directly added with fluorinated difluoromethane sulfonylimide as an auxiliary ligand L to obtain the colorless and transparent complex ligand barium precursor salt Ba(tmhd)2(L). With the technology, aggregation of the Ba(tmhd)2 precursor salt in the post-treatment process to form Ba4(tmhd)8 low-ploidy which is not easy to evaporate is inhibited, preparation of the complex ligand barium precursor salt is greatly simplified, and YBCO (yttrium barium copper oxide) superconducting films with excellent superconductivity are prepared by the aid of the complex ligand barium precursor salt.

The invention discloses a method of preparing a Tl-1223 superconductive thin film. In the invention, a thallium-containing amorphous precursor film and a thallium-containing sintering accompanying target are sealed and coated with a silver foil or a gold foil, and then sintering is carried out in a sealed argon gas or a flowing oxygen environment. In the method, phase forming temperature zone of low-temperature phases, such as Tl-1212 and Tl-2212, can be crossed quickly and Tl-1223 superconductive phase temperature zone is directly reached, thus producing a pure-phase thin film. The method isshort in temperature increase / decrease time and constant temperature time and is low in production cost.

The invention discloses a preparation method of a Tl-2223 superconducting thin film. Silver foil or gold foil is used to seal and wrap an amorphous precursor film containing thallium and a burning target containing thallium, and place the film in a sealed argon or oxygen flow environment. Sintering; wherein, the metal ion molar ratio of Tl, Ba, Ca, Cu of the amorphous precursor film containing thallium is 2.4~4.5:2:2:3.2~3.8; Tl:Ba:Ca:Cu=0.8~1.2:2:1~2:2~3 Ba, Ca, Cu oxides and Tl 2 o 3 Made by sintering. The present invention can quickly cross the phase forming temperature zone of Tl-1212, Tl-2212, Tl-1223 and other low-temperature phases, and directly reach the superconducting phase temperature zone of Tl-2223, thereby preparing a pure-phase film, which has heating and cooling time and constant temperature time Advantages of short length and low production cost.