36results about How to "Consistent coefficient of thermal expansion" patented technology

The invention discloses a method for plugging a cast-in-situ concrete slab or base-plate crack with microbe-sedimented calcium carbonate. The method includes preparation of plugging materials, plugging of the cast-in-situ concrete slab crack and plugging of the cast-in-situ base-plate crack. A method for preparation of the plugging materials includes preparation of calcium source solutions, preparation of nutrient salt solutions and preparation of microbial solutions; a method for plugging of the cast-in-situ concrete slab crack includes that the pressure grouting mode is adopted on base of the crack, the top surface and bottom surface of the plugged crack are sealed with rubber tapes, and water solutions are ensured to flow out with bacteria filtered within the crack; a rubber hose is inserted in the bottom of the other end of the crack, and an injector is connected with the rubber tube; the injector is utilized to inject the microbial solutions, the nutrient salt solutions and the calcium source solutions with the volume ratio of 1:1:1, and fluid is ensured to seep from the position of a gauze; grouting work is repeated once every 24 hours for 5 days; the gauge, the rubber tube, the injector and the sealing rubber tapes are removed. By the method, problems of durability of rusting and the like caused by exposure of steel bars inside plates can be effectively solved.

The invention discloses a power thick-film resistor which comprises a resistor substrate provided with a printed internal electrode and a resistor both on one surface as well as a printed back electrode on the other surface, wherein a heat-conducting plate is arranged on the surface of the back electrode of the resistor substrate in a matching manner, and is a porcelain substrate of which the inner surface and the outer surface are fixedly coated with an inner heat-conducting fin and an outer heat-conducting fin respectively; the surface of the inner heat-conducting fin is plated with a nickel layer; the nickel layer is oppositely welded and fixed with the back electrode on the resistor substrate in a matching manner. The porcelain substrate of which the inner surface and the outer surface are coated with the inner heat-conducting fin and the outer heat-conducting fin in a welding manner is welded on the surface of the back electrode of the resistor substrate to serve as the heat-conducting plate, and the heat-conducting fins on the two surfaces cancel out each other due to temperature distortion so as to enable the thermal expansion coefficient of the heat-conducting plate to be basically the same as that of the resistor substrate, so that the problem that the resistor substrate cracks due to the inconsistent thermal expansion coefficient during the use of the resistor substrate in a large size resistor is solved; the power thick-film resistor has the advantages that under the condition of the same size, the resistor is larger in power compared with a conventional resistor, the stable performance is realized, and the temperature distortion cannot be caused.

The invention belongs to the technical field of ceramic connection and discloses a method for connecting SiC ceramics by nano impregnating transient eutectic phase. The method is to combine SiC powder and Al 2 o 3 -M x o y The mixed powder A is used as the connecting material, the M x o y = Ho 2 o 3 or CeO 2 , the mixed powder A is added to the solvent and the ball milling medium, mixed and dried, and the obtained mixed powder B is granulated, and the powder is spread in the middle of two polished SiC to form a sandwich structure; Under the protection of the atmosphere, pressurize 0.01-0.1MPa, first raise the temperature to 600-1000°C for heat preservation Ⅰ, then raise the temperature to 1450-1600°C for heat preservation Ⅱ, the heat preservation pressure is 200-500MPa, and connect to obtain nano-impregnated transient eutectic phase connection SiC ceramics. The invention realizes the low-temperature and low-pressure connection of SiC ceramics, and the leakage rate of the connection reaches 0-1×10 ‑ 8 Pa·L / s.

The invention provides an electronic chip packaging method in order to eliminate the cost disadvantage of the prior art. With the electronic chip packaging method adopted, the production cost of a whole process is effectively reduced. The electronic chip packaging method is characterized by comprising the following steps of: a, obtaining a finished product carrier, and forming a groove in the finished product carrier; b, mounting a chip on a substrate; and c, mounting the substrate with the chip into the groove.

The invention discloses a heat preservation and intelligent anticorrosion oil pipe for a high sulfur natural gas well. The heat preservation and intelligent anticorrosion oil pipe is composed of six layers which are an inner anticorrosion anti-drag layer (6), an inner intelligent anticorrosion layer (5), a heat preservation layer (4), a supporting layer (3), an outer intelligent anticorrosion layer (2) and an outer anticorrosion anti-drag layer (1) in sequence; the inner intelligent anticorrosion layer (5) is wrapped outside the inner anticorrosion anti-drag layer (6); the heat preservation layer (4) is wrapped outside the inner intelligent anticorrosion layer (5); the supporting layer (3) is wrapped outside the heat preservation layer (4); the outer intelligent anticorrosion layer (2) is wrapped outside the supporting layer (3); the outer anticorrosion anti-drag layer (1) is wrapped outside the outer intelligent anticorrosion layer (2). The heat preservation and intelligent anticorrosion oil pipe has the beneficial effects that the oil pipe has excellent thermal stability and non-corrosibility; each functional layer has the capacities of compression resistance, heat preservation, intelligent anticorrosion, drag reduction and attaching prevention respectively; the coefficients of thermal expansion of the functional layers are the same; the problem that heat preservation and anticorrosion materials for conventional heat preservation and anticorrosion tubular products are easy to fall off is solved.

The invention discloses a minitype dynamic infiltration water pressure sensor which comprises a shell, a cup-shaped base, a stainless steel rear cover, a water permeable stone layer and a signal modulation amplification module. A step surface is arranged on the inner wall of the cup-shaped base, and the water permeable stone layer is mounted on the step surface of the cup-shaped base. The cup-shaped base is embedded into a front cavity and is mounted on the step circular ring surface of the shell. The stainless steel rear cover is mounted at the end, placed on a rear cavity, of the shell, and a silicon nitride thin film covers the inner surface of the cup-shaped base. A pressure sensitive assembly is arranged on the surface, opposite to the water permeable stone layer, of the cup-shaped base, a first leading wire is connected between the pressure sensitive assembly and one end of the signal modulation amplification module in a bridging mode, and a signal cable is embedded into a through hole of the stainless steel rear cover and is connected to the other end of the signal modulation amplification module through a second leading wire. By means of the minitype dynamic infiltration water pressure sensor, the dynamic frequency response and the measurement accuracy of the pressure sensor are improved, the measuring range is greatly increased, sensing precision and sensitivity are also improved, and the degree of linearity of signals of the pressure sensor is improved.

The invention discloses a high radiant ceramic coating for a heating furnace tube as well as a preparation method and a using method thereof. The high radiant ceramic coating for the heating furnace tube comprises a component A and a component B, wherein the component A is a metallic oxide mixture which is 30-35% of the total amount and the component B is a temperature resistant bonder which is 65-70% of the total amount. The high radiant ceramic coating provided by the invention has the functions of anti-high temperature oxidation and anticorrosion, prolongs the service life of the furnace tube, increases the heat transfer on the surface of the furnace tube, increases the heat exchange efficiency, reduces the fuel consumption of the heating furnace and reaches the energy saving purpose; under the condition of not changing the device structure, the high radiant ceramic coating reinforces the radiative transfer, is few in investment, rapid in effect, simple in construction and good for industrial popularization.

The invention belongs to the technical field of sensors and concretely relates to a flux gate magnetic sensor with a novel magnetic core skeleton structure. An inner frame and an outer frame are adopted to cooperate with each other, a magnetic core wound by an excitation coil is arranged in a first chamber in the inner frame, an induction coil is wound around the inner frame, and a feedback coil is wound around the outer frame, so uniformity of a feedback field can be ensured. Moreover, the cooperation between the inner and outer frames enables installation to be easier, the later calibrationwork to be easier, and facilitates batch production. Meanwhile, the frames made from PEEK, which is lighter, cheaper and easier to process compared with materials of a conventional sensor, and the frames also has the advantages of electrical insulation, high temperature resistance, light weight, high tensile strength, basic consistence between thermal expansion coefficients and enameled wires, etc.