43 results about "High critical temperature" patented technology

A coil comprises a set of windings with a generally annular shape and formed by a plurality of series-connected partial windings made of a superconductor with a high critical temperature, in which these partial windings are arranged next to each other in stratified form, and at least one cooling sheet which is made of thermally conductive material and arranged in contact with this set of windings and which is designed to be connected in a thermally conductive manner to a cryogenic cooling system.

A superconductive element containing Nb₃Sn, in particular a multifilament wire, comprising at least one superconductive filament (8) which is obtained by a solid state diffusion reaction from a preliminary filament structure (1), said preliminary filament structure (1) containing an elongated hollow pipe (2) having an inner surface (3) and an outer surface (4), wherein said hollow pipe (2) consists of Nb or an Nb alloy, in particular NbTa, wherein the outer surface (4) is in close contact with a surrounding bronze matrix (5) containing Cu and Sn, and wherein the inner surface (3) is in close contact with an inner bronze matrix (5) also containing Cu and Sn, is characterized in that the inner bronze matrix (5) of the preliminary filament structure (1) encloses in its central region an elongated core (6) consisting of a metallic material, said metallic material having at room temperature (=RT) a thermal expansion coefficient α_core<17*10⁻⁶K⁻¹, preferably α_core≦8*10⁻⁶ K⁻¹, said metallic material having at RT a yield strength R_p0.2>300 MPa, said metallic material having at RT an elongation at rupture A>20%, and wherein the metallic material of the core (6) is chemically inert with respect to the material of the inner bronze matrix (5) up to a reaction temperature T of the solid state diffusion reaction. This element has improved superconductive properties in a large volume fraction of its superconductive filaments, in particular a high critical temperature T_c and a high critical magnetic filed strength B_c2, and is mechanically stable enough for commercial applications such as magnet coils.

The invention provides a high resolution proton nuclear magnetic reonance and imaging (NMR/MRI) in microtesla magnetic fields by using high critical temperature (high-T_c) superconducting quantum interference device (SQUID) magnetometer via a flux transformer. Both the SQUID and the input coupling coil are installed inside a superconducting vessel which shields environmental noise and set the SQUID in a stable operation condition. The present invention also offers the advantages of preserving the NMR signal even if the sample is far away from the SQUID detector.

A method for reducing corrosion of a superheater of a steam boiler. The superheater includes a superheater piping. The superheating piping includes a steam pipe where the steam to be superheated is directed. The steam pipe is separated by a protective shell having a surface settling in the flue gas space has a temperature that rises above an upper critical temperature, above which temperature in the flue gas space the compounds from the fuel are substantially in a gaseous form. A superheater of a steam boiler and a circulating fluidized bed boiler.

The present invention provides a low-noise MEG apparatus of high sensitivity. A MEG apparatus using a magnetic shield of high critical temperature superconductor is set on the floor of a building via mechanical vibration suppressor supports to prevent appearance of noise signals. Also, the apparatus is equipped with means for preventing any relative displacement between the SQUID magnetic sensors and the magnetic shield of high critical temperature superconductor, thereby not letting an inevitable mechanical vibration of least strength produce any variable components of the trapped static magnetic field, which the SQUID magnetic sensors could be sensitive to.

A superconductive contact or contact structure composed mainly of superconductors and a hydroxide-catalyzed bond that establishes electrical contacts, retains superconductivity, and provides the full mechanical fastening strength between the superconductors. According to the present invention, the superconductive contact structure exhibits a single-film superconductive behavior. In some embodiments, the structure has a configuration of two metallic low critical-temperature (low-T_c) superconductors, such as niobium (Nb), connectorized by an essentially transparent and extremely thin hydroxide-catalyzed bond. In some embodiments, two ceramic high critical-temperature (high-T_c) superconductors, such as perovskite ceramics (e.g., YBa₂Cu₃O₇ or YBCO in general) are joined via a hydroxide-catalyzed bond. In some embodiments, a metallic low-T_c superconductor and a ceramic high-T_c superconductor is connectorized via a hydroxide-catalyzed bond.

The invention discloses a double-working-medium organic Rankine cycle power generation system, and belongs to the technical field of medium-low temperature heat source power generation. On the basis of a conventional organic Rankine cycle, a flash evaporation cycle which is provided with an ejector and uses a working medium with a low critical temperature is additionally arranged; the organic Rankine cycle uses a working medium with a high critical temperature, and the flash evaporation cycle uses the working medium with a low critical temperature; a circulation loop of the organic Rankine cycle is composed of a preheater, a first evaporator, a first expansion machine, a first condenser and a first working medium pump; a circulation loop of the flash evaporation cycle is composed of a second evaporator, a flash evaporation tank, a second expansion machine, an ejector, a second condenser and a second working medium pump. According to the double-working-medium organic Rankine cycle powergeneration system, the heat source at an outlet of the first evaporator is shunted and enters the preheater and the second evaporator respectively, two cycles are heated simultaneously, and the massflow of the working medium heated by the low-temperature part of the heat source is increased, so that the matching degree of the heat source is improved, the heat absorption amount of the system is increased, and the output work of the system is increased.

Disclosed are a superconducting article and a process for manufacturing such an article. The superconducting article comprises at least one core material including a superconductive material or one or more materials that are convertible into a superconductive material; at least one first matrix of a first material surrounding said at least one core material; at least one reinforcement matrix of a second material partially surrounding said first material; wherein said reinforcement matrix comprises at least one opening in a circumference of said reinforcement matrix, said opening allowing oxygen to reach the first matrix during at least one step of a manufacturing process of the superconducting article; and at least one third matrix of a third material surrounding said second material.

The invention provides a graphene / doped two-dimensional layered material Van der Waals heterojunction superconducting composite structure, a superconducting device and a manufacturing method thereofand relates to the superconducting material technology field. A graphene layer and a layered structure of 2n + 1 layers formed by alternative doped two-dimensional layered materials are included. Anouter layer of the layered structure is the graphene layer, and the n is an integer of 1 to 50. A region where graphene and the doped two-dimensional layered material are completely overlapped vertically forms a superconducting region. The graphene layer and the doped two-dimensional layered material are self-assembled into one body by a Van der Waals force. A defect that an existing Van der Waalsheterojunction superconducting material can only work at an extremely low temperature is solved. The graphene / doped two-dimensional layered material heterojunction superconducting material has a simple structure, excellent performance, a high critical temperature and a high critical magnetic field, low material cost, and good mechanical and machining performance.

The invention discloses a novel magneto-electric coupling multi-ferroic material and a preparation method thereof. A chemical formula of the novel magneto-electric coupling multi-ferroic material is BiMn3Cr4O12. The method for preparing the novel magneto-electric coupling multi-ferroic material BiMn3Cr4O12 comprises the following steps: mixing Bi2O3, Mn2O3 and Cr2O3 of which the purities are more than 99.9% according to a molar ratio of 1:3:4, and then fully grinding and screening; filling screened raw materials into gold capsules or platinum capsules and compacting; and performing solid-phase reaction at high temperature and high pressure. The novel magneto-electric coupling multi-ferroic material BiMn3Cr4O12 disclosed by the invention has weak ferromagnetic spin orders, relatively large dielectric constants and electric dipolar polarization strength as well as relatively high critical temperature, and has good application prospects in the fields of spin electronic devices and multi-state memory devices.

A preparation method for MgB₂ super-conductors characterizing in sintering a mixed powder of Mg and B in the atomic ratio of 1:4 then adding suitable volume of Mg powder in it to be sintered for the second time to get the MgB₂ super-conductor.

Rare earth metal containing compounds of the formula Sr₂LuSbO₆ have been prepared with high critical temperature thin film superconductor structures, and can be fabricated into an antenna, as well as being used in other ferroelectrics, pyroelectrics, piezoelectrics, and hybrid device structures.

A compressor variable frequency control system applied to a refrigerator is used for being arranged in the refrigerator provided with a refrigerator door and a compressor, and comprises a mechanical change-over switch, a sensing unit, a comparing unit and a processing unit, wherein the mechanism change-over switch is provided with a position change stroke which is provided with a low-critical temperature setting point and a high-critical temperature setting point; the sensing unit is used for sensing first operation stop time when the compressor stops operating; the comparing unit is provided with second operation stop time, and is used for comparing the first operation stop time with the second operation stop time when the mechanical change-over switch is switched to the high-critical temperature setting point; and the processing unit is provided with an operation frequency compensation meter comprising a corresponding relationship of first and second operation stop time difference and a first compensation frequency, and is used for deciding to increase or decrease the frequency of the compressor according to the magnitudes of the first and second operation stop time.

The resistive current limiting device comprises a strip-shaped superconductor (2) whose conductor structure (7) contains: at least one metallic substrate strip (3), a layer (5) made of oxidic high Tc superconducting material of the AB2Cu3Ox type; an oxidic buffer layer (4), which is arranged therebetween and which has adapted crystalline dimensions, and; a normal-conductive top layer (6) that is applied to the superconductive layer (5). The buffer layer (4) should be formed so that a transition resistance of no greater than 10<-3> Omega.cm<2> is formed at least in partial areas between the superconductive layer (5) and the substrate strip (3). For example, suitable materials are of the La-Mn-O or Sr-Ru-O or La-Ni-O or In-Sn-O type.

Superconducting ceramics having relatively high critical temperatures are composed of rare earth metals, alkaline earth metals and copper. They have few defects and a limited polycrystalline interfacial area.

The invention discloses high temperature superconducting material and a method for preparing the high temperature superconducting material. The high temperature superconducting material is composed of yttrium, aluminum, nickel, lithium, zinc, barium and boron of which the molar ratio is 1:6-9:1-3:2-6:3-6:1.5:1-2. The preparation method comprises the steps that 1) a nitrate mixed solution is prepared; 2) citric acid is added in the nitrate mixed solution; 3) heating concentration is performed on the mixed solution obtained in the step 2) until gel is completely combusted so that powder material is formed; 4) powder is evenly ground; and 5) the ground powder is put in a high temperature furnace for calcining and then taken out after cooling to room temperature so that superconducting material is obtained. A sol-gel method and a high temperature calcining method are adopted for preparation so that the homogeneous superconducting material is formed, the defect of low critical temperature of the existing superconducting material can be solved, the superconducting material having higher critical temperature is prepared, and the superconducting material has the superconductivity under the condition of high temperature.

The present invention relates to an MgB₂-based superconductor that is easy to manufacture and well suited to mass production, and that exhibits excellent superconducting characteristics (such as a high critical current density) while still retaining the high critical temperature characteristics of MgB₂. A powder mixture of magnesium, boron, and titanium is pressed into a pellet, and this product is sintered under an atmospheric pressure and other conditions (preferably at 600° C. or higher) to manufacture an MgB₂-based superconductor in which titanium and/or a titanium compound are dispersed in polycrystalline MgB₂. The composition of the MgB₂-based superconductor is preferably adjusted to have an atomic ratio of Mg:B:Ti=x:2:y, 0.7<x<1.2 and 0.05<y<0.3, and more preferably 0.07<y<0.2, by adjusting the amounts in which the raw materials are added.

In the production of an internal-tin-processed Nb₃Sn superconducting wire, the present invention provides a Nb₃Sn superconducting wire that is abundant in functionality, such as, the promotion of formation of a Nb₃Sn layer, the mechanical strength of the superconducting filament (and an increase in interface resistance), the higher critical temperature (magnetic field), and the grain size reduction, and a method for producing it. A method for producing a Nb₃Sn superconducting wire according to an embodiment of the present invention includes a step of providing a bar 10 that has a Sn insertion hole 12 provided in a central portion of the bar 10 and a plurality of Nb insertion holes 14 provided discretely along an outer peripheral surface of the Sn insertion hole 12, and that has an alloy composition being Cu-xZn-yM (x: 0.1 to 40 mass %, M=Ge, Ga, Mg, or Al, provided that, for Mg, x: 0 to 40 mass %), a step of mounting an alloy bar with an alloy composition of Sn-zQ (Q=Ti, Zr, or Hf) into the Sn insertion hole 12 and inserting Nb cores into the Nb insertion holes 14, a step of subjecting the bar 10 to diameter reduction processing to fabricate a Cu-xZn-yM/Nb/Sn-zQ composite multicore wire with a prescribed outer diameter, and a step of subjecting the composite multicore wire to Nb₃Sn phase generation heat treatment.