43 results about "High critical temperature" patented technology

The present invention provides an improved, commercially available organic working fluid, which is operable under a broad range of temperatures, is thermally stable, has a high auto-ignition temperature, low freezing point and high critical temperature and is benign to the environment, and safe for human use. Such an organic working fluid is useful in organic Rankine cycle (ORC) power plants or units and other systems of the like; as an intermediate fluid for heat-recovery wherein heat from various heat sources is transferred using the intermediate fluid to a further working fluid and converted into work, and the intermediate fluid is also exploited to produce electricity. Such organic working fluids are also operable as heat transfer fluids either in ORC power plants or units or in other heat transfer systems. For this purpose the present invention presents a working fluid comprising at least one highly branched, heavy iso-paraffin hydrocarbons, or a mixture of two or more of such hydrocarbons. Preferably, at least one highly branched iso-paraffin hydrocarbon is present as the major component (i.e. at least 50% by volume) in the working fluid. A preferred sub-class of the class of the branched iso-paraffins which are suitable to be incorporated in organic working fluids of the present invention includes 8 to 20 carbon atom-containing hydrocarbons having at least one methyl radical (CH3) arranged to achieve a highly stable compound.

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 αcore<17*10−6K−1, preferably αcore≦8*10−6 K−1, said metallic material having at RT a yield strength Rp0.2>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 Tc and a high critical magnetic filed strength Bc2, 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-Tc) 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.

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 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-Tc) 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-Tc) 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-Tc superconductor and a ceramic high-Tc 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.

A process for producing a (Bi,Pb)2Sr2Ca2Cu3Oz superconducting oxide material which comprises a step in which raw materials are mixed and two or more heat treatment steps in which the mixed materials are heat-treated. The heat treatment steps comprise a first heat treatment step in which (Bi,Pb)-2223 crystals are formed and a second heat treatment step in which after the formation of the (Bi,Pb)-2223 crystals, the strontium content in the (Bi,Pb)-2223 crystals is heightened. The second heat treatment step is conducted at a lower temperature than the first heat treatment step. Thus, a (Bi,Pb)-2223 type superconducting oxide material having a high critical temperature is obtained.

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 DEG 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.

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.

A method for increasing the critical temperature, T.sub.c, of a high critical temperature superconducting (HTS) film (104) grown on a substrate (102) and a superconducting structure (100) made using the method. The HTS film has an a-b plane parallel to the surface of the substrate and a c-direction normal to the surface of the substrate. Generally, the method includes providing the substrate, growing the HTS film on the substrate and, after the HTS film has been grown, inducing into the HTS film a residual compressive strain the a-b plane and a residual tensile strain into the c-direction.

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.

The invention provides a high resolution proton nuclear magnetic reonance and imaging (NMR / MRI) in microtesla magnetic fields by using high critical temperature (high-Tc) 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.

Disclosed is a measuring structure for a magneto encephalographic equipment superconducting magnetic-shield comprising a vacuum-tight body comprising an outer enclosure wall, a first inner enclosure wall inserted in the outer enclosure wall to define an upper closed space, and a second inner enclosure wall to define a lower open space. The first and second inner enclosure walls are arranged with the bottom of the first inner enclosure wall facing the ceiling of the second inner enclosure wall. A first enclosure of high critical temperature superconductor and a second enclosure of high permeability material are concentrically arranged in the annular vacuum space defined between the first and second inner enclosure walls and the outer enclosure wall. A head-accommodating area is delimited by the hollow partition between the bottom of the first inner enclosure wall and the ceiling of the second inner enclosure wall both facing each other, and a plurality of SQUID sensors are arranged in the upper closed space, encircling the head-accommodating area. The SQUID sensors are cooled by the liquid helium contained in the upper closed space whereas the first enclosure is cooled by the circulating helium gas from a closed-cycle helium refrigerator. An adiabatic expansion compartment may be placed in the upper closed space. The adiabatic expansion compartment is supplied with cooled helium gas, which is converted into liquid helium by adiabatic expansion, and the so converted liquid helium is led into the liquid helium bath in the form of drops to make up for the consumption of liquid helium during operation. Otherwise, the adiabatic expansion compartment is connected to the SQUID magnetic sensors to indirectly cool the sensors by the thermal conduction body.

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.

The invention provides a temperature anomaly protecting method which is applied to a server. The method includes the steps that operation is responded, and a corresponding input signal is generated; the input signal is responded, the temperature value of each part in the server is determined according to the input signal, the temperature value is compared with the dangerous critical temperature threshold value and the highest critical temperature threshold value of one corresponding part stored in a storage cell, when it is determined that the temperature value of each part in the server meets a preset temperature anomaly condition, a preset countdown time period is read from the storage cell, and a countdown unit is controlled to start counting down; after counting down is over, shutdown operation is executed. The invention further provides the server using the temperature anomaly protecting method. According to the server and the temperature anomaly protecting method thereof, when temperature anomaly is determined, counting down is started, after counting down is completed, automatic shutdown is achieved, and thus the server can be prevented from being damaged due to temperature anomaly.

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 invention discloses a superconducting material and a preparation method thereof and relates to the technical field of materials. The superconducting material consists of oxides of yttrium, aluminum, nickel, lithium and zinc, wherein the mass ratio of the yttrium to aluminum to nickel to lithium to zinc is 1:(5-9):(1-3):(2-6):(3-7). The method for preparing the superconducting material comprises the following preparation steps: (1) preparing a nitrate mixed solution; (2) adding citric acid, and regulating pH; (3) combusting sol gel; (4) grinding the powder; and (5) putting the ground powder into a high temperature furnace for calcining, cooling, and taking out the material, thereby obtaining the superconducting material. According to the superconducting material and the preparation method thereof provided by the invention, the superconducting material is a superconductor consisting of metal oxides and consists of five oxides of yttrium, aluminum, nickel, lithium and zinc, and the yttrium-aluminum-nickel-lithium-zinc material has a superconducting phenomenon at high temperature and has relatively high critical temperature.

An electronics system includes an electronic device, a power source and a temperature control switch. An actuator having a shape memory alloy is attached to the temperature control switch and moves the temperature control switch between an open position preventing a current flow between the power source and the electronic device, and a closed position permitting current flow between the power source and the electronic device. The shape memory alloy transforms shapes upon the ambient temperature falling below a low critical temperature or rising above a high critical temperature to move the temperature control switch into one of the closed position to permit current flow to the electronic device or the open position to prevent current flow to the electronics device respectively.

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.

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.