66 results about "Temperature wave" patented technology

A platinum/Rhodium resistance thermal probe is used as an active device which acts both as a highly localized heat source and as a detector to perform localized differential calorimetry, by thermally inducing and detecting events such as glass transitions, meltings, recystallizations and thermal decomposition within volumes of material estimated at a few mu m3. Furthermore, the probe is used to image variations in thermal conductivity and diffusivity, to perform depth profiling and sub-surface imaging. The maximum depth of the sample that is imaged is controlled by generating and detecting evanescent temperature waves in the sample.

The invention relates to a high-temperature wave-absorbing composite material and a preparation method thereof and provides a SiC@SiO2@ferrite high-temperature wave-absorbing composite material and apreparation method thereof. The objective of the invention is to overcome the technical problems of complex preparation technologies, narrow wave-absorbing ranges and no shielding effect of conventional wave-absorbing material preparation methods. The wave-absorbing composite material uses SiC as a core; a SiO2 layer coats the core; and ferrite particles are adhered onto the SiO2 layer. The preparation method comprises the following steps: 1, pretreating the surface of silicon carbide; 2, synthesizing silica-coated silicon carbide SiC@SiO2; 3, after sensitization and activation of SiC@SiO2, reacting the SiC@SiO2 with a salt for preparing ferrite and a strong reducing agent in alkaline liquor, then carrying out calcination so as to obtain the SiC@SiO2@ferrite high-temperature wave-absorbingcomposite material. The material of the invention has a reflection loss of less than -5dB in a 8-to-12-GHz band and a Ku band and a maximum reflection loss of -14 dB, and can be used in the field ofwave-absorbing materials.

Systems and methods for performing chromatography separations or analyses are disclosed. The methods are based upon an equilibrium gradient focusing mode in contrast to conventional transient migration-based modes. By matching the migration speed of one or more analyte(s) of interest to the wave speed of a thermal gradient induced to travel along a region in which chromatographic partitioning occurs, significant improvements in detection limits are achieved. In particular, a temperature gradient focusing strategy is described in which analyte(s) of interest are circulated around a continuous chromatography system in order to focus the analyte(s). Also described are various devices and systems that can be used in the methods described herein.

The invention discloses a silicon nitride fiber reinforced silicon dioxide ceramic based composite and a preparation method and application of the silicon nitride fiber reinforced silicon dioxide ceramic based composite. The silicon nitride fiber reinforced silicon dioxide ceramic based composite comprises an Si3N4 fiber prefabricate and an SiO2 ceramic base, and the SiO2 ceramic base is evenly put in holes of the Si3N4 fiber prefabricate. The preparation method comprises the following steps: (1) removing a binder from the Si3N4 fiber prefabricate in the vacuum or inertia atmosphere; (2) preparing an Si3N4/SiO2 composite intermediate through the processes of impregnating in vacuum, drying a gel and sintering; and (3) decarbonizing thermally in the aerobic environment. The composite has the advantages of high temperature resistance, ablation resistance, scouring resistance, excellent oxidation resistance, strong carrying capacity and excellent dielectric property, and has an excellent application value in the field of high temperature wave transmitting material; and the preparation method is simple in process and relatively low in cost and is suitable for industrial production.

The invention relates to an energy-saving easily-changeable high-temperature microwave heating chamber and a manufacturing method thereof, which belong to the technical field of microwave high-temperature heating technology. The energy-saving easily-changeable high-temperature microwave heating chamber mainly comprises the following functional layers: an internal high-temperature microwave absorbing coating, a medium high-temperature wave-transmitting thermal insulating layer and an external wave-transmitting hardened layer. The manufacturing method is characterized by comprising the following steps: firstly, mixing a microwave absorbing component and water glass and/or commercial high-temperature glue (mud) to prepare slurry; secondly, uniformly coating the slurry on the high-temperature wave-transmitting thermal insulating layer to form a chamber internal surface in a certain shape; and finally, obtaining the energy-saving easily-changeable high-temperature microwave heating chamber by drying and preburning. The energy-saving easily-changeable high-temperature microwave heating chamber has the advantages of simple structure, easy change, low cost, large heating area, high thermal efficiency, convenient maintenance, high safety due to non-contact heating, supper-fast and ultra-temperature heating, and remarkable energy conservation effect and obvious economic benefits due to the selection because of the changing and using of heating chambers of various sizes according to the sizes of materials to be heated.

The invention relates to a high-temperature-resistant high-strength tough silicon nitride based wave-transparent composite material and a preparation method thereof. The preparation method comprises the following steps: preparing a porous Si3N4 whisker biscuit through gel casting, and performing drying and rubber discharging to obtain a porous Si3N4 preform; and preparing a boron nitride (BN) interface in the whisker preform through a chemical vapor infiltration (CVI) process, and preparing a multilayer alternate BN/Si3N4 matrix through the CVI process. In accordance with the design requirements for the structure and performance of a high-temperature wave-transparent antenna housing, the microstructure of each layer, the number of layers and the layer thickness of the multilayer alternateBN/Si3N4 matrix are regulated and controlled through CVI regulation and control to realize the regulation, control and optimization of the structure and performance of the composite material, therebyobtaining the high-temperature-resistant high-strength high-toughness Si3N4 based wave-transparent composite material which realizes broadband wave transmission and has excellent thermophysical properties.

The invention discloses a method for comparison test of thermal performance of two walls and a test device. The test device comprises a test frame, two walls with different properties, temperature sensors, heat flow sensors and a data collecting and recording terminal. The method comprises the steps of collecting parameters of internal temperature distribution and surface heat flow transfer and the like under same heat transfer boundary conditions, of the two walls with different properties in the test frame, by utilizing the temperature sensors and the heat flow sensors; and carrying out comparative analysis on difference between the two walls on the aspects of the attenuation and the delay of temperature waves, heat transfer coefficient thermal performance parameters according to test data, wherein by applying the alternating temperature waves, specific values of the attenuation coefficients and the delay time of the two test walls can also be obtained respectively under periodic boundary conditions. The method disclosed by the invention has the advantages that not only can the advantages and the disadvantages of the thermal performance of the two walls be directly compared, butalso the test error can be reduced and the accuracy of the comparative analysis is improved. The device has the advantages of being simple in structure, low in manufacturing cost and convenient to install.

The invention discloses silicon carbide composite wave absorbing ceramic based on a metamaterial. The silicon carbide composite wave absorbing ceramic is composed of a silicon carbide composite layer, an antioxidant bonding layer and a metamaterial layer from inside to outside in sequence. The silicon carbide composite layer is composed of a three-dimensional knitted part reinforced silicon carbide composite sewn through continuous silicon carbide fiber plain cloth in the Z direction, and the fiber electrical resistivity of the composite ranges from 10<5> omega.cm to 10<6> omega.cm; the antioxidant bonding layer is composed of a cordierite coating, and the metamaterial layer is formed by periodically arranging resistance coatings of capacitive or inductive periodic patterns. The advantages of achieving wide frequency and low frequency wave absorption, being resistant to high temperature, high in wave absorbing performance regulation and control performance, achieving bearing and the like are integrated, the technical problem of poor low frequency wave absorbing performance troubling a high-temperature wave absorbing material all the time is solved, the structure is simple, implementation is easy, and high designability is achieved. The invention further discloses a preparation method of the silicon carbide composite wave absorbing ceramic based on the metamaterial. The raw materials are easy to obtain, and engineering application is convenient.

The invention provides a preparation method of a high-temperature wave-transparent composite material toughened by hybrid-woven fibers. The preparation method comprises the following steps: (1), weaving boron nitride fibers, high silica fibers and quartz fibers into prefab forms in a hybrid manner by virtue of a weaving method or a knitting method, wherein the prefab types are 2.5-dimensional or 3-dimensional forms; (2), mixing phosphoric acid in a certain mass fraction with aluminum hydroxide, adding deionized water and sufficiently stirring until mixing uniformly, and standing for 2 hours-4 hours to prepare aluminum phosphate sol; (3), placing fiber prefabs in the prepared aluminum phosphate sol, and sufficiently impregnating; (4), placing the fiber prefabs impregnated by the aluminum phosphate sol into an oven for carrying out a thermal-treatment drying process; (5), placing a dried composite material at 700 DEG C-900 DEG C for sintering and treating for 1 hour-2 hours; and (6), repeating the processes in step (3) to step (5) for 5-7 times to prepare the compact composite material. According to the invention, the technical process is relatively simple, easy to operate and low in cost; and the prepared composite material has very good high temperature resistance and wave-transparent performance.

The invention discloses a pressure differential defrosting device of an evaporator in an air cooler of a refrigerated storage. The technical scheme provided by the invention is that left and right static pressure boxes are arranged on both sides of the air cooler, the two static pressure boxes are respectively provided with pressure differential fans, and the pressure differential fans are respectively connected to the lower left and upper right air outlets through the circulating air flues. Electric heaters are respectively arranged at the lower left and upper right ends of the evaporator. Electric air valves are respectively arranged on the air outlet between the two static pressure boxes and the air cooler, the upper and lower ends of the air cooler and the air inlet and return openings of a blowing fan. According to the device, a pressure differential fan, the static pressure boxes and the electric heaters are optimized and combined, and the device is directly contacted with the surface frost layer of the evaporator to defrost through hot air, so that the defrosting time is effectively shortened. Heated air flows circularly around the evaporator in the air cooler and in the static pressure boxes to defrost, so that the defrosting energy utilization ratio is improved, and meanwhile, the defrosting warehouse temperature wave in the refrigerated storage is avoided. The plurality of diffusers and electric air valves arranged effectively solve the problem of the defrosting dead angle.

The invention discloses a preparing method of homogeneity fused quartz ceramic. The preparing method comprises the step A, mixing high purity fused quartz powder; adding quartz powder material into deionized water as well as polyvinyl alcohol, lactic acid and sodium sesquicarbonate to make slurry; B, conducting mixing of 40wt% acrylamide aqueous solution with N,N'-Methylenebisacrylamide N,N'-Methylenebis (2-propenamide) to obtain premixed liquid; C, conducting mixing of the slurry in the step A, sintering aid and the premixed liquid in the step B, and adding initiator to obtain formed slurry after dispersion; D, pouring the formed slurry in the step C into a mold of a dynamic gel casting device, conducting solidification after vibration, and opening the mold after cooling, so that the green ceramic required is obtained; E, firing the green ware body in the step D in a high temperature wave until being molded, so that the fused quartz ceramic required is prepared.

The invention belongs to the technical field of chip aluminum electrolytic capacitors and particularly relates to a chip high-voltage miniature long-life aluminum electrolytic capacitor and a manufacturing method thereof. The chip high-voltage miniature long-life aluminum electrolytic capacitor comprises outer electrolytic paper, a positive guide pin, anode foil, a negative guide pin, cathode foil and inner electrolytic paper. The positive guide pin is riveted on the anode foil and the negative guide pin is riveted on the cathode foil. The outer electrolytic paper, the anode foil, the inner electrolytic paper and the cathode foil are wound together into a core package. The riveted portions between the positive guide pin and the anode foil as well as between the negative guide pin and the cathode foil are respectively provided with a hydrophilic high temperature electrically conductive adhesive tape. The anode foil is an anode foil of high voltage withstanding and high specific volume and the cathode foil is a forming cathode foil. The inner electrolytic paper and the outer electrolytic paper are electrolytic paper of low tightness and low thickness. The chip high-voltage miniature long-life aluminum electrolytic capacitor has the advantages of being provided with one hydrophilic high temperature electrically conductive adhesive tape at the riveted portions between the positive guide pin and the anode foil as well as between the negative guide pin and the cathode foil respectively for significantly reducing the size of the core package and increasing the contact area for further achieving the characteristics of miniaturization and high temperature wave resistance of the product.

The invention relates to an ultrasonic measuring probe suitable for on-line detection at high temperature. The ultrasonic measuring probe at least comprises a support seat (1), an energy converter cavity (3) and an ultrasonic energy converter (4), wherein the ultrasonic energy converter (4) is connected in the energy converter cavity (3); a wave guide rod (2) is arranged between the ultrasonic energy converter (4) and the support seat (1); the front end of the wave guide rod (2) is fixed with the support seat (1); the back end of the wave guide rod (2) is connected with the ultrasonic energy converter (4). When an object to be tested at high temperature is detected, partial heat of the object to be tested is radiated and dissipated into the space through fin-shaped heat radiation pins; theheat conducted though high-temperature wave guide oil is limited; the change of high sound velocity generated by the high-temperature wave guide oil in sound waves cannot be influenced. The structureis simple; the realization is convenient; the cost is low.

A cartridge containing an environmentally friendly percussion primer employing a primer explosive mixture, packed under the paper disc and anvil; the mixture being a metastable interstitial composite (MIC) and a high explosive; and a second mass of high explosive, packed within the primer cup above the anvil—which mass of high explosive is ignited by the detonation of the MIC and high explosive mixture—thereby adding to the detonation to create a combined, enhanced pressure and temperature wave to more quickly initiate the booster pellet and propellant, to fire the bullet within the subject action time limit—even under extreme cold ambient conditions.

The invention relates to an internal thermally coupled rectifying tower control device based on temperature wave characteristics. The device comprises an internal thermally coupled rectifying tower, an intelligent instrument, a control station, a data storage device and an upper computer, wherein the intelligent instrument is connected with the internal thermally coupled rectifying tower; the control station is connected with the internal thermally coupled rectifying tower; the data storage device is connected with the intelligent instrument and the control station; and the upper computer is connected with the data storage device and the control station and comprises a concentration gradient description module, a temperature gradient description module, a static temperature wave description module, a dynamic temperature wave description module, a set value conversion module and a control parameter solution module. According to the device disclosed by the invention, a nonlinear control scheme is established on the basis of a high-precision nonlinear model, and the interference effect can be timely inhibited; the coupling problem is well solved, and the set value change can be rapidly and accurately tracked; and moreover, the temperature with high measurement precision and small measurement time delay is taken as a main control means, and the control speed and control performance are greatly improved.

The invention relates to ceramic precursor carbon-free polyborosilazane and a synthesis method thereof. The carbon-free polyborosilazane is a polymer simultaneously containing a Si-N bond and a B-N bond, and pure silicon nitride boron ceramic is obtained after carrying out pyrolysis on the polymer simultaneously containing a Si-N bond and a B-N bond. The carbon-free polyborosilazane obtained by the synthesis method is low in viscosity, good in flowability, and suitable for a precursor dipping-cracking process; and the yield of ceramic is up to 83%, the pyrolysis product is the pure silicon nitride boron ceramic which is suitable for high temperature wave-penetrating materials. The synthesis method of the carbon-free polyborosilazane has the advantages that the operation is simple, the reaction is mitigated and stable, and the controllability is strong.

The invention discloses a SiBCN metal-free ceramic wave-absorbing material obtained from cracking conversion of benzene ring-containing polymer and a preparation method thereof, wherein the preparation method includes synthesis of benzene ring-containing hyperbranched polyborosilazane and preparation of the SiBCN ceramic wave-absorbing material. The hyperbranched polyborosilazane is synthesized bymethyl dichlorodiphenylsilazane, dichlorosilazane, boron trichloride and hexamethyldisiliazide, then the hyperbranched polyborosilazane is crosslinked and tabletted into a blank body, and the blank body is cracked into the ceramic wave-absorbing material. Starting from the design of the structure of a ceramic polymer precursor, synthesis of a high ceramic yield polyborosilazane precursor and construction of a crosslinking topology system are performed, and the benzene ring is directly introduced into the structure of the polyborosilazane precursor, so that sp2 hybrid carbon atoms in the benzene ring directly form graphite carbon, carbon nanotubes and other structures in situ in cracking conversion process, the high temperature wave absorbent is uniformly dispersed in the structure of an amorphous low-loss carrier, and the metal-free ceramic based composite material with good wave absorbing properties is obtained.

The invention relates to a portable temperature-wave energy-moxibustion generator and a production method thereof, which mainly utilizes the temperature-sensing connection between a heating unit and a temperature detecting unit, the electrical connection between an arithmetic unit and the temperature detecting unit, the electrical connection between a loop control unit and the arithmetic unit, the electrical connection between an electric power supply unit and the loop control unit as well as a line connection that electric energy is converted into heat energy between the electric power supply unit and the heating unit; by detecting the temperature of the heating unit, making decision to production trend of heat energy of the heating unit and feeding back dynamic electric power as a server for regulating heat energy, the temperature produced in the heating unit raises from low and reduces from high, and the proper dynamic temperature energy can be accurately provided according to different temperature requirement (due to time function) of any parts of the human body for a long time. The invention has the effects that the use is convenient and the generator can be hung on any aching parts of the human body directly; aches at the affected parts can be relieved rapidly, blood vessels can be regulated to be smooth, the blood circulation is improved, and the moxibustion effect is achieved.

The invention discloses a heat radiating process method for a printed-circuit board, belongs to electron technology, and applies to the technical field of avionics. The a cold plate is bonded on a printed-circuit board through a dedicated bonding device, a component is enabled to grovel on the cold plate, and heat radiating is carried out through the bonding membrane material and the cold plate, wherein the membrane material is arranged among the printed-circuit board base materials, the metal conducting materials on the inner portion and the surface of the printed-circuit board, the printed-circuit board and the cold plate. The cold plate is formed by arranging holes in an aluminium alloy plate according to the welding locating of the components of the printed-circuit board through hard anodic oxidation surface treatment. The bonding material between the printed-circuit board and the cold plate is a polyimide double-faced adhesive membrane. The bonding device is a convex thick steel mold plate and a concave thick steel mold plate with a certain curvature, and enables the printed-circuit board and the cold plate can be completed a flattening function simultaneously with bonding. The heat radiating process method for the printed-circuit board achieves the processing of the bonding and the flattening of the cold plate and the printed-circuit board at one time, solves the problem of product performance deterioration due to the fact that heat emitted by component after being powered on can not be released in time, increases the mechanical strength, the antiseptic property and the insulating property of the printed-circuit board, and restrains the layer splitting and the deformation of the printed-circuit board generated by high-temperature wave soldering.

The invention specifically relates to a method for preparing boron nitride fiber cloth by using precursor conversion, which belongs to the technical field of ceramic materials. The method comprises the following steps: (1) subjecting boric acid to fusing and wire drawing so as to obtain single-bunch boric oxide fiber yarns; (2) stranding and cabling 2 to 10 boric oxide fiber yarns into a thick single-bunch boric oxide fiber yarn and braiding the thick single-bunch boric oxide fiber yarn to obtain boric oxide fiber cloth; (3) subjecting the boric oxide fiber cloth to low-temperature nitridation heat treatment in an ammonia gas atmosphere so as to obtain boric oxide fiber cloth; and (4) carrying out high-temperature heat treatment on the boric oxide fiber cloth. The method provided by the invention is simple, can easily realize large-scale production, overcomes the problem of incapable direct weaving due to insufficient strength of boron nitride fiber, and provides a basic raw material with excellent performance for preparation of high-temperature wave-transmitting materials, heatproof materials and battery diaphragms.

The invention belongs to the technical field of electronic materials, relates to an electromagnetic wave absorbing material, and particularly relates to a high-temperature wave absorbing metamaterial and a preparation method thereof. The metamaterial comprises a plurality of conductive ceramic chips, a ceramic dielectric substrate and a reflecting back plate, wherein the plurality of conductive ceramic chips are fixed on a surface of the ceramic dielectric substrate by bonding, and are arranged as periodic units to form a conductive ceramic array; and the reflecting back plate is fixed on the other surface of the ceramic dielectric substrate. Compared with the prior art, the metamaterial has the advantages that the metamaterial can nearly completely absorb electromagnetic wave at certain frequency, is simple in structure, thin, simple in preparation and easy to adjust in performance, and can realize broadband absorption by certain design and show good wave absorbing performance at a high temperature.