30results about How to "Stable temperature coefficient" patented technology

The invention relates to the field of material science and engineering, and aims to provide a PTFE substrate material for a high-frequency copper-clad plate and a preparation method of the PTFE substrate material. The substrate material comprises polytetrafluoroethylene with a volume ratio of (100-x)% and modified ceramic powder with a volume ratio of x%, wherein x is greater than or equal to 20 and less than or equal to 60. The chemical formula of the modified ceramic powder is aBa (Co1 / 3Nb2 / 3) O3-(1-a) Ba (Zn1 / 3Nb2 / 3) O3, wherein 0.2 < = a < = 0.7. The substrate material provided by the invention has the advantages of high dielectric constant, low dielectric loss, proper dielectric constant temperature coefficient and resonant frequency temperature coefficient; meanwhile, the thermal expansion coefficient is low, the water absorption rate is low, and the heat conductivity is proper. The preparation method disclosed by the invention is simple to operate, does not need special equipment and complicated experimental processes, is high in universality, and has a very good industrial basis and a very good application prospect.

The invention discloses a high-voltage electric proportional valve. The high-voltage electric proportional valve comprises a housing assembly, an electromagnetic valve, a first piston rod, an air pressure sensor, a second piston rod, a button, a circuit board assembly, a display screen and a fiber-rubber diaphragm, wherein an input opening is formed in the rear end of the housing assembly, and anoutput opening is formed in the front end of the housing assembly; the button is connected with the circuit board assembly; the circuit board assembly is controlled by a single-chip microcomputer; theair pressure sensor is connected with the circuit board assembly; the electromagnetic valve is connected with the circuit board assembly; the first piston rod is arranged on the housing assembly; thefiber-rubber diaphragm is arranged in the housing assembly; the second piston rod is connected with the fiber-rubber diaphragm; and the display screen is arranged on the housing assembly. The high-voltage electric proportional valve disclosed by the invention is simple in structure, the control accuracy of the high-voltage electric proportional valve can achieve 10kPa level, the control precisionand the number displaying precision are high, and the high-voltage electric proportional valve is low in power consumption, long in service life, compact in volume and stable in temperature coefficient; and besides, a user can accurately master and control the magnitude of output air pressure, and can know the corresponding number displaying value.

The invention discloses a strontium bismuth and titanium base energy storage medium material for medium temperature sintering and a preparation method. The medium material is prepared from a base material, a modifying agent and sintering auxiliaries; the base material is SrO-xBi2O3-(1+3x)TiO2, wherein 0.04<=x<=0.11; the modifying agent includes one or more of MnCO3, Mg(OH)2, Co2O3, SiZrO3, CeO2 and Y2O3; the sintering auxiliaries include two or more of H3BO3, ZnO, CaCO3 and SiO2. The SrO-xBi2O3-(1+3x)TiO2 base material is prepared by adopting a solid phase method, and the adjustable energy storage dielectric material with the high dielectric constant, disruptive strength and insulation resistivity, low consumption and sintering temperature and stable temperature coefficient is obtained byadding the modifying agent and the sintering auxiliaries.

The invention relates to a high resistivity nickel wire. The nickel wire comprises 99.5-99.94% of Ni, 0.035-0.26% of Mn, 0.026-0.24% of Si, less than 0.03% of Ti and less than 0.03% of rare earth in mass percentages. The invention also discloses a preparation method for the nickel wire. The nickel wire provided by the invention has the advantages that the resistivity is greater than 0.092 omega.mm<2> / m and is obviously higher than the 0.07 omega.mm<2> / m resistivity of the existing national standard nickel wire, and the temperature coefficient is stable and is 0.0045+0.0002, thereby solving the problem that as the temperature coefficient of the national standard nickel wire is unstable, the service life of an electrical appliance is short when the national standard nickel wire is used in heating industries; and compared with the prior art, the high resistivity nickel wire has very remarkable effect.

The invention discloses microwave dielectric ceramic powder and a preparation method and application thereof. The microwave dielectric ceramic powder comprises ceramic powder prepared from the following raw materials in parts by weight: 35 to 45 parts of strontium carbonate, 15 to 25 parts of titanium oxide, 25 to 35 parts of lanthanum oxide, 5 to 15 parts of aluminum oxide, 0.1 to 0.2 part of cerium oxide and 0.008 to 0.02 part of manganese oxide. The microwave dielectric ceramic powder prepared by the method is a microwave dielectric material with a dielectric constant of 40, a high QxFo [ceramic quality factor] value and low loss, the electrical performance of microwave components such as a cavity filter can be significantly improved, especially the insertion loss of the filter is reduced, and a more stable temperature coefficient is obtained so that the influence on the filter due to use environment factors in actual use is reduced.

The invention relates to a low temperature co-firing ceramic (LTCC) composition for microwave frequency represented by the following formula 1:Ca[(Li1 / 3Nb2 / 3)1-xTix]O3-δ+y(B2O3.ZnO.SiO2.PbO)  (1)wherein x is molar ratio and 0≦x≦0.3; and y is wt % ratio and 0≦y≦15. The present invention relates to dielectric LTCC composition for microwave frequency that has high dielectric constants, high Q values, and stable temperature coefficients of the resonant frequency, and has sintering temperature as low as ≦900° C. so as to be co-fired without reaction with an electrode such as silver (Ag). The compositions have excellent characteristics required to cellular phones and PCS in the range of 800 MHz˜1.9 GHz, which is commonly used, and laminated chip filters and antennas in the range of IMT 2000 of 2 GHz, which will be used.

The invention discloses a twin-wire separation resistance type molten metal liquid level sensor and belongs to the technical field of sensors. The sensor is used in the detection of a molten metal liquid level in a closed, high-temperature and high-pressure environment. According to the twin-wire separation resistance type molten metal liquid level sensor, an Ni18Cr20 resistance wire is adopted, the resistance wire is divided into the outer resistance wire and the inner resistance wire, the outer resistance wire is a working resistance wire, and the inner resistance wire is a temperature compensation resistance wire. The outer resistance wire is wrapped with ceramic fiber paper and loaded in a corundum ring to configure an adhesion removing device, the corundum ring floats in a high-temperature molten metal solution, and the corundum ring is soaked in the high-temperature molten metal solution when in working; the temperature compensation resistance wire serves as a contrast, the influence of temperature change on sensor measurement results can be effectively reduced, the temperature compensation resistance wire is packaged in the corundum ring, the resistance wire can be effectively protected and the service life of the resistance wire is improved. The molten metal liquid level sensor has the advantages of being in high in measurement accuracy, large in measurement range, low in cost and long in service life.

The invention provides a surge protection circuit and a chip, comprising: a power tube, which is arranged between the input terminal and the ground voltage; a multi-level control branch, which is arranged between the input terminal and the ground voltage, and the latter-level control branch is connected to The control terminal of the upper-level control branch provides control voltage to the upper-level control branch when the latter-level control branch is turned on, and determines whether the upper-level control branch is turned on; the first-level control branch is connected to the power tube The control terminal of the power tube provides the first control voltage to the power tube when the first-stage control branch is turned on to determine whether the power tube is turned on; the voltage dividing branch is set between the input terminal and the control terminal of the power tube, and is connected to the last The first-stage control branch generates a divided voltage based on the input voltage of the input terminal and the first control voltage of the control terminal of the power tube, and provides it to the last-stage control branch to determine whether the last-stage control branch is turned on. The temperature coefficient of the VIN clamping voltage of the circuit is stable, the clamping voltage can be adjusted continuously, and the surge tolerance is strong.

The invention discloses a high dielectric constant NPO dielectric ceramic; a high dielectric constant NPO dielectric ceramic comprises magnesium metatitanate (MgTiO 3 )5‑250 parts, calcium titanate (CaTiO 3 )5‑150 parts, titanium dioxide (TiO 2 )5‑100 parts, neodymium trioxide (Nd 2 o 3 ) 5-350 parts, modified additives 5-200 parts and sintering aids 50-120 parts; the present invention has the advantages of very stable temperature coefficient, low sintering temperature, high dielectric constant and small dielectric loss.

The invention relates to a high resistivity nickel wire. The nickel wire comprises 99.5-99.94% of Ni, 0.035-0.26% of Mn, 0.026-0.24% of Si, less than 0.03% of Ti and less than 0.03% of rare earth in mass percentages. The invention also discloses a preparation method for the nickel wire. The nickel wire provided by the invention has the advantages that the resistivity is greater than 0.092 omega.mm<2> / m and is obviously higher than the 0.07 omega.mm<2> / m resistivity of the existing national standard nickel wire, and the temperature coefficient is stable and is 0.0045+0.0002, thereby solving the problem that as the temperature coefficient of the national standard nickel wire is unstable, the service life of an electrical appliance is short when the national standard nickel wire is used in heating industries; and compared with the prior art, the high resistivity nickel wire has very remarkable effect.

The invention discloses a strontium-bismuth-titanium-based energy storage medium material for medium temperature sintering and a preparation method, comprising a base material, a modifier and a sintering aid; the base material is SrO-xBi 2 O 3 ‑(1+3x)TiO 2 , 0.04≤x≤0.11; the modifier includes MnCO 3 , Mg(OH) 2 , Co 2 O 3 , and SrZrO 3 , CeO 2 and Y 2 O 3 One or more of them; sintering aids include H 3 BO 3 , ZnO, CaCO 3 and SiO 2 two or more of them. The invention adopts the solid phase method to prepare SrO-xBi 2 O 3 ‑(1+3x)TiO 2 Base material, by adding modifiers and sintering aids, an energy storage medium with high dielectric constant, breakdown strength and insulation resistivity, low loss and sintering temperature, and a stable and adjustable temperature coefficient can be obtained Material.

The invention provides microwave dielectric ceramic powder and a preparation method thereof and relates to the field of electronic information materials and elements. The microwave dielectric ceramic powder specifically comprises the following components in percentage by weight: 85-96% of strontium and cobalt doped ZnO-MgO-TiO2 ternary system microwave dielectric material and 4-15% of zinc-barium-boron-silicon fluxing agent. The technical problem to be solved by the invention is to provide the microwave dielectric ceramic powder and the preparation method thereof; and by using the microwave dielectric ceramic powder and the preparation method thereof, the loss is effectively reduced and ceramic can keep excellent dielectric property and have a stable temperature coefficient.

The invention discloses an R-T-B permanent magnet material, a preparation method and an application thereof. The R-T-B is a permanent magnet material, which includes the following components: R': 29.5-33.0wt.%, said R' includes R and Pr, Nd; wherein: said R is except for Pr, Nd Rare earth elements, the content of the Pr ≥ 8.85wt.%, the mass ratio of the Nd and the R' <0.5; N: > 0.05wt.%, and ≤ 4.1wt.%, the N is Ti, Zr or Nb; B: 0.90‑1.2 wt.%; Fe: 62.0‑68.0 wt.%. The present invention uses a formula with high Pr content to prepare a sintered permanent magnet product with high coercive force and stable temperature coefficient. The formula of this application can maximize the advantages of Pr and effectively reduce production costs.

This invention disclose an unpulp basic material loudspeaker cone and its manufacturing technology. The basic material of the cone is an unwoven cloth, proportion of its weight percentage is: specific ceramic fiber 0-30, carbon fiber: 0-30, anti-bomb fiber 0-30, nylon fiber 0-20, cotton fiber 50-95. Its basic material can be woven cloth with the proportion of : specific ceramic fiber 0-30, glass fiber 0-100, carbon fiber 0-100, anti-bomb fiber 0-100. The manufacturing technology is :to be processed to cloth->dying->gluing->cutting the material to be formed by hot pressure->(compound)->(gluing)->cutting edge->lapping edge.

The invention provides a microwave dielectric ceramic material with medium and high dielectric constants and a preparation method thereof. The general chemical formula of the microwave dielectric ceramic material is Ca(Fe,Nb)1-x / 2TixO3. The preparation method comprises the following steps: mixing CaCO3 and TiO2 and carrying out wet ball milling so as to obtain a sample A; mixing CaCO3, Nb2O5 and Fe3O4 and carrying out wet ball milling so as to obtain a sample B; and mixing the sample A and the sample B, carrying out wet ball milling and drying so as to obtain a sample C, adding an aqueous polyvinyl alcohol solution into the sample C, carrying out granulation, sieving, dry pressing and sintering in an air atmosphere. The preparation method provided by the invention is simple, needs a short period and is suitable for mass production; the prepared ceramic material can be used as a microwave dielectric material and has density of more than 97%, the material has a high material quality factor and a stable temperature coefficient while maintaining medium and high dielectric constants, and the microwave dielectric ceramic material has medium and high dielectric constants and a near-zero temperature coefficient of resonant frequency.

The invention discloses improved microwave dielectric ceramic powder and a preparation method and application thereof. The microwave dielectric ceramic powder comprises ceramic powder prepared from the following raw materials in parts by weight: 30-40 parts of calcium carbonate, 25-30 parts of titanium dioxide, 25-35 parts of samarium oxide, 5-15 parts of aluminum oxide, 0.5-2 parts of cerium oxide and 0.01-0.5 part of niobium oxide. The improved microwave dielectric ceramic powder prepared by the method is a microwave dielectric material with high QxFo [ceramic quality factor] value and low loss of dielectric constant 43, the electrical performance of microwave components such as a cavity filter can be significantly improved, especially the insertion loss of the filter is reduced, and a more stable temperature coefficient is obtained so that the influence on the filter due to use environment factors in actual use is reduced.

The invention provides a rubidium atomic clock of an atomic gas chamber with a compound-eye type stacked dense multi-bubble structure. The atomic gas chamber is an atomic gas chamber with the compound-eye type stacked dense multi-bubble structure and comprises a glass shell and a medium, the glass shell is filled with the medium and internally provided with a plurality of micro-atomic bubbles formed by glass walls and stacked in a dense and compound-eye mode, and the micro-atomic bubbles are filled with rubidium atoms and buffer gas. The whole atomic gas chamber formed by the multi-bubble structure replaces single-bubble atomic gas chambers to achieve the function of balancing the temperature drift and pressure frequency shift of an alkali metal atomic gas chamber, and therefore the constraints caused by the temperature and pressure changes of rubidium absorbing bubbles on the long-term frequency stability index of a rubidium atom frequency standard are effectively solved. The rubidiumatomic clock can solve the problem troubling technicians in the field for a long time in the world that the long-term frequency stability of bubble-type rubidium atoms is influenced by the temperature drift and pressure frequency shift of the single-bubble atomic gas chambers.

The invention provides an atomic gas chamber of a compound eye-type stacked dense multi-bubble structure. The atomic gas chamber comprises a glass shell and a filled medium, a plurality of micro-atomic air bubbles configured by glass walls are also arranged in the glass shell, and the micro-atomic air bubbles are filled with alkali metal atoms and a buffer gas. The atomic gas chamber of the compound eye-type stacked dense multi-bubble structure provided by the invention can stabilize the temperature coefficient and suppress the frequency shift, and solve the constrain of the bubble-type germanium atomic frequency standard and the rubidium atomic magnetometer on the long-term frequency stability index due to the changes of the temperature and pressure of the atomic chamber, thereby solvingthe problem of long-term frequency drift. The technical scheme of the invention provides atomic gas chambers with lower temperature coefficients, temperature fluctuation and less pressure shift for applications requiring higher demands such as atomic clocks, atomic magnetometers, atomic filters, and Faraday active light clocks, etc.