225results about How to "Good dielectric" patented technology

Microstrip patch antenna (46), feed structure (48), and matching circuit (50) designs for an RFID tag (10). A balanced feed design using balanced feeds coupled by a shorting stub (56) to create a virtual short between the two feeds so as to eliminate the need for physically connecting substrate to the ground plane. A dual feed structure design using a four-terminal IC can be connected to two antennas (46a,46b) resonating at different frequencies so as to provide directional and polarization diversity. A combined near/field-far/field design using a microstrip antenna providing electromagnetic coupling for far-field operation, and a looping matching circuit providing inductive coupling for near-field operation. A dual-antenna design using first and second microstrip antennas providing directional diversity when affixed to a cylindrical or conical object, and a protective superstrate (66). An annual antenna (46c) design for application to the top of a metal cylinder around a stem.

A dielectric ceramic includes a compound represented by the general formula: (Ba_1-tCa_t)_m(Ti_1-u-xZr_uCu_x)O₃ (where 0.96≦m≦1.02, 0.001≦x≦0.03, 0≦t≦0.1, and 0≦u≦0.06) as a primary component, a rare earth element Re such as Dy, a metal element M such as Mn, Mg, and Si. In the dielectric ceramic, the Cu is uniformly and dispersedly present in the primary phase grain forming the primary component, and the contents of the accessory components with respect to 100 molar parts of the primary component are 0.1 to 1.5 molar parts of Re, 0.1 to 0.6 molar parts of M, 0.1 to 1.5 molar parts of Mg and 0.1 to 2.0 molar parts of Si. Accordingly, a multilayer ceramic capacitor can be realized which has a high dielectric constant, superior temperature properties, and a high reliability, and also has a small change in electrostatic capacitance with time.

The invention discloses a positive and negative mixed liquid crystal composition. The positive and negative mixed liquid crystal composition is characterized by comprising an additive component A which consists of one or more compounds shown in a general formula S-1, a general formula S-2, a structural formula S-3 and a structural formula S-4, a component B which consists of one or more negative compounds shown in a general formula I and a component C which consists of one or more positive compounds shown in a general formula II. According to the positive and negative mixed liquid crystal composition, the problems of low transmittance, low response speed and especially poor anti-ultraviolet capability of the conventional liquid crystal mixture are solved.

Microstrip patch antenna (46), feed structure (48), and matching circuit (50) designs for an RFID tag (10). A balanced feed design using balanced feeds coupled by a shorting stub (56) to create a virtual short between the two feeds so as to eliminate the need for physically connecting the substrate to the ground plane. A dual feed structure design using a four-terminal IC can be connected to two antennas (46a,46b) resonating at different frequencies so as to provide directional and polarization diversity. A combined near-field/far-field design using a microstrip antenna providing electromagnetic coupling for far-field operation, and a looping matching circuit providing inductive coupling for near-field operation. A dual-antenna design using first and second microstrip antennas providing directional diversity when affixed to a cylindrical or conical object, and a protective superstrate (66). An annular antenna (46c) design for application to the top of a metal cylinder around a stem.

The invention discloses a positive-negative-mixed liquid crystal composition. The positive-negative-mixed liquid crystal composition comprises an additive component A, a component B and a component C, wherein the additive component A comprises one or more compounds shown in formula S-1, formula S-2, formula S-3 and structural formula S-4, the component B comprises one or more negative compounds shown in formula I, and the component C comprises one or more positive compounds shown in formula II. By the positive-negative-mixed liquid crystal composition, the problems that existing liquid crystal compositions are low in transmittance, slow in response and poor in UV resistance are solved.

The invention discloses a rare earth doped bismuth titanate up-conversion luminescence ferroelectric film and a preparation method thereof. The rare earth doped bismuth titanate up-conversion luminescence ferroelectric film has the molecular formula of (Bi4-x-yErxYby)Ti3O12, wherein 0<x<=0.85, 0<y<=0.85, and 0<x+y<=0.85. The invention adopts a chemical solution-deposition method to prepare (Bi4-x-yErxYby)Ti3O12 films, the film components are easily controlled, the operation is convenient, and the invention is convenient for scale production. Besides good ferroelectric, dielectric and optical transmittance properties, the (Bi4-x-yErxYby)Ti3O12 film further has efficiently enhanced up-conversion luminescence property, is a novel important multifunctional film material, and has wide application prospect in the field of photoelectric material.

The invention discloses a positive-negative-mixed liquid crystal composition. The positive-negative-mixed liquid crystal composition is characterized by comprising a component A composed of at least one kind of negative compounds shown in the first general formula (please see the specification for the first general formula) and a component B composed of one or more kinds of positive compounds shown in the second general formula (please see the specification for the second general formula). The liquid crystal composition has the advantages of being positively dielectric, high in charge retention rate, low in rotary viscosity, short in response time and particularly high in transmittance; the positive-negative-mixed liquid crystal composition is suitable for manufacturing a high-transmittance and rapid-responding TFT-LCD.

The invention provides a method for preparing an Nd/Co-codoped BiFeO3 film on an FTO (fluorine-doped tin oxide)/glass substrate surface, which comprises the following steps: after cleaning an FTO substrate, carrying out ultraviolet irradiation, and dissolving bismuth nitrate (8% excessive), ferric nitrate, neodymium nitrate and cobalt nitrate which serve as raw materials in mixed ethylene glycol monomethyl ether and acetic anhydride in a mol ratio of 0.98:(1-x):0.1:x (x=0.01-0.05), thereby obtaining a stable BiFeO3 precursor solution of which the metallic ion concentration is 0.1-0.5mol/L; and after spin coating, drying to obtain a dry film, preannealing, naturally cooling, repeating the process above to obtain the film with expected thickness, and finally, annealing to obtain the crystalline BiFeO3 film. In the invention, the facility requests are simple, the experiment conditions can be easily achieved, the prepared film has good uniformity, the doping amount is easy to control, andthe dielectric properties of the film can be greatly enhanced by doping.

The invention discloses a doped and modified lead zirconate-titanate piezoelectric ceramic and a preparation method thereof. The doped and modified lead zirconate-titanate piezoelectric ceramic is shown in a following chemical formula I, namely xPb(Mg1/3Nb2/3)O3-yPb(Ni1/3Nb2/3)O3-(1-x-y)Pb(Ti1/2Zr1/2)O3+lSrCO3+mZnO+nQ, wherein Q is at least selected from Li2CO3 (lithium carbonate), CuO (copper oxide), SiO2 (silicon dioxide), MnO2 (manganese dioxide), Bi2O3 (bismuth oxide) and La2O3 (lanthanum oxide); l, m and n are respectively the mass percentages of SrCO3 (strontium carbonate), ZnO (zinc oxide) and Q in the compound Pb(Mg1/3Nb2/3)O3-Pb(Ni1/3Nb2/3)O3-Pb(Ti1/2Zr1/2)O3; x is greater than or equal to 0.10 and is smaller than or equal to 0.70, y is greater than or equal to 0.08 and is smallerthan or equal to 0.38, l is greater than 0 and is smaller than or equal to 0.5, m is greater than 0 and is smaller than or equal to 0.50, and n is greater than or equal to 0 and is smaller than or equal to 0.5. The doped and modified lead zirconate-titanate piezoelectric ceramic has the excellent properties of low sintering temperature, high electromechanical coupling coefficient, high piezoelectric strain coefficient, small dielectric loss and the like.

The invention discloses a polymer matrix composite material containing a filler particle three-dimensional network and a preparation method thereof. The polymer matrix composite material comprises thefiller particle three-dimensional network composed of filler particles and a polymer filled in the gaps of the filler particle three-dimensional network, the unique structure can well guarantee thatthe specific reinforcement effect of the filler particles with specific properties on the polymer matrix composite material can be brought into play, and the performance is far superior to discrete composite materials prepared by traditional methods. The method provided by the invention includes: firstly utilizing a support material to construct filler particles into a three-dimensional structure,then sintering the filler particles into a three-dimensional network continuous structure of filler at high temperature, removing the support material at high temperature, or further conducting acidtreatment after high temperature to remove the support material, and finally filling the filler forming the three-dimensional structure with the polymer material to form the polymer matrix composite material. The preparation method provided by the invention is simple, and is suitable for industrial production.

An NMR probe includes a coil former on which the resonant capacitance and/or tune and match capacitances are integrally implemented. Adjustable capacitances are realized in combination with a composite former including a slip glass for support of a capacitor plate. Particular advantages are realized in the context of cryostatic NMR probes.

The invention discloses a centralized cooking oil fume treating and recycling system which comprises an early-stage pretreatment unit, an electrostatic purification oil removal unit with a pump oil removal function, a later-stage air purification unit and an exhaust fan, wherein the early-stage pretreatment unit, the electrostatic purification oil removal unit, the later-stage air purification unit and the exhaust fan are sequentially connected through pipelines along the oil fume running direction; the electrostatic purification oil removal unit comprises a high voltage electric field generating area, a high voltage cathode electrode, a high voltage anode electrode, an oil pump, a hydraulic pressure gauge and a detachable collection container; the high voltage electric field generating area is formed in an oil fume inlet of the electrostatic purification oil removal unit; the high voltage cathode electrode and the high voltage anode electrode are vertically opposite to each other; the high voltage anode electrode is connected with the hydraulic pressure gauge, and oil on the high voltage anode electrode can be discharged into the collection container through the oil pump along the pipeline. Energy in the waste oil fume is utilized to the greatest degree when an electrostatic treatment device is not required to be detached, so that the device is simplified, and the aims of energy conservation and environment friendliness are achieved.

The invention discloses a preparation method of a high-dielectric and low-loss composite material with a laminated structure, and relates to the technical field of composite material preparation. A positive dielectric material and a negative dielectric material are adopted as raw materials and are subjected to hot-pressing lamination to obtain the composite material. The positive dielectric material and the negative dielectric material are subjected to lamination, and the thicknesses and values of the positive and negative dielectric materials are matched, so that the dielectric constant is improved. The obtained composite material can obtain the remarkably-improved dielectric constant while the 10<-2> order of magnitudes and low losses are kept.

The invention provides a liquid crystal compound containing a dibenzofuran ring. The liquid crystal compound has a structure as shown in the formula I in the description. The liquid crystal compound containing the dibenzofuran ring has larger dielectric anisotropy, lower rotational viscosity and higher clearing point, and the intersolubility among monomers is good, thereby being favorable for preparing a composition. A liquid crystal composition containing the liquid crystal compound has greater dielectric anisotropy, can more effectively reduce the driving voltage of a device, simultaneouslyhas lower rotational viscosity and shorter response time, has good chemical stability and thermal stability, has good application in a display device, and especially has good application in a displaydevice in a TFT mode.

The objective of the invention is to provide lead zirconate titanate/ruthenium acid strontium ferroelectric superlattice material and a preparation method thereof. The material is formed by periodically grown ferroelectric material lead zirconate titanate and metallically conductive oxide material ruthenium acid strontium. The advantages of the lead zirconate titanate/ruthenium acid strontium ferroelectric superlattice material are that the dielectric constant is increased for 2-10 times than that of a pure PZT film; and the material has great ferroelectric polarization performance, and its saturated polarization value is higher than that of the pure PZT film and can be 80muC/cm2. The preparation method of the material is that ruthenium acid strontium and lead zirconate titanate are alternately grown on a monocrystal substrate by using a pulse laser deposition method, and the periodic thickness of the superlattice is accurately regulated and controlled by controlling bombardment time of laser for different target material. The ferroelectric superlattice material has wide application prospect in sensors, storage devices and other integrated ferroelectric devices.

The invention relates to polyamine containing a triazole ring and a preparation method and application thereof. The preparation method of the polyamine comprises the following steps of: preparing an azide by a nucleophilic substitution reaction; synthesizing the polyamine containing the triazole ring by the Huisgen cycloaddition reaction of the azide and a compound with alkynyl amine; and applying the polyamine containing the triazole ring to the preparation of polyimide. The invention has the following advantages that: polytriazole imide has superior processable property and can be dissolved in polar solvents, such as DMAc, DMF, DMSO, NMP and the like; the prepared polytriazole imide has the properties of the polyimide, such as superior heat resistance, low-temperature resistance, chemical resistance, mechanical properties, dielectric and insulation properties, fire retardance, bonding properties and the like; the polytriazole imide can be used as a functional polyimide material and is especially suitable for serving as a metal coating material and a corrosion-resistant material; and the novel polytriazole imide material has extensive application prospect in the fields of aviation, spaceflight, ships, micro-electronics and the like.

The invention discloses a method for preparing polyvinylidene fluoride (PVDF)-constructed composite particles with a nuclear shell interpenetrating network structure. The method comprises the following steps of: adding deionized water into PVDF seed emulsion, performing ultrasonic dispersion, adding monomers, after the temperature of a system is raised to reaction temperature, adding initiator, and polymerizing; and decompressing the emulsion, drying at low temperature until the weight of the emulsion is constant to prepare the composite particles with the nuclear shell interpenetrating network structure. The composite particles with the nuclear shell interpenetrating network structure are formed based on PVDF seeds, effectively combine the respective characteristics of two polymers, and have complementary advantages of the two polymers; the crystallization temperature of PVDF can be reduced from 142.5 DEG C to 71.4 DEG C in differential scanning calorimetry (DSC); and melting processability of the PVDF, and the compatibility between the PVDF and other polymers which are not compatible with the PVDF are improved, the dielectric performance, piezoelectric performance, ferroelectric performance and other performance of the PVDF can be improved, and the composite particles can be widely applied to the fields of optical fiber coating, outdoor painting and coating, dental repairing and the like.

The invention provides a preparation method of high-dielectric para-aramid fiber paper. The preparation method of the high-dielectric para-aramid fiber paper comprises the following steps: mixing para-aramid chopped fibers, para-aramid pulp and para-aramid nano fibers to obtain mixed pulp; and sequentially performing online forming, pressing, drying and calendaring forming on the mixed pulp to obtain the high-dielectric para-aramid fiber paper. According to the invention, the para-aramid nanofibers or the suspension slurry thereof are added, so that the para-aramid nanofibers, the para-aramidchopped fibers and the para-aramid pulp can be better used as a filling material to be combined with macroscopic fibers in a papermaking process, paper page gaps are filled, the combination of the fibers is enhanced, the paper page gaps are reduced, the combination of the fibers is compact after hot pressing, and various performance indexes of paper pages are improved while the paper forming uniformity is increased. The invention also provides the high-dielectric para-aramid fiber paper.

Disclosed is high elasticity wave-absorbing anticorrosion nanometer coating with the weight ratio composition of 1-5% nanometer titanium alloy, 1-10% carbon fiber, 1-10% copper powder, 13-25% T-ZnO, 15-30% magneto plumbite type ferrite and 25-68% epoxy modified acrylic acid elastic resin; the radius of nanometer titanium alloy is 20- 50nm; the radius of carbon fiber is 20-30nm and the length of carbon fiber is 100-500nm; the radius of the particle of copper powder is 20-30nm; the radius of the particle of T-ZnO is 40-70nm; the radius of magneto plumbite type ferrite is 20-100nm and the length is 100-300nm; the Rho of epoxy modified acrylic acid elastic resin is equal to 1.1-1.2. The high elasticity wave-absorbing anticorrosion nanometer coating has super strong anticorrosion property and avoids the device from corrosion when the device operates under badly corrosive environment for long time; the anticorrosion nanometer coating is bonded firmly with the substrate and has the advantages of high elasticity and good wave-absorbing performance.

The invention relates to a novel nano composite phase-change material and a preparation method thereof. The nano composite phase-change material is characterized in that a phase-change material and a ferroelectric material are compounded, and the ferroelectric material separates the phase-change material into even nano-scale areas with controllable shapes and sizes so as to limit the phase change of the phase-change material within a small area; and simultaneously, because the ferroelectric material has good dielectric and insulating properties, the ferroelectric material enhances the dielectric property and breakdown resisting capability of the composite material, inhibits the growth of phase-change material crystals, promotes the specific resistance of the material, and increases the heat capacity of the material. The novel nano composite phase-change material applied to a memory is favorable for achieving high-density storage, improves heating efficiency during programming of a phase-change memory, reduces the power consumption of the memory, improves the storage speed, and promotes data retention capability, fatigue property, radiation resistance and the like.

The invention relates to high performance leadless piezoelectric ceramics and its preparation technology, the preparation technology comprises the following steps: burdening titanium dioxide, barium carbonate and stannic oxide according to stoichiometric ratio of 0.89: 1: 0.11, ball milling, pre-burning, performing secondary ball milling, granulation granulating and molding, covering by a crucible finally, putting in a sintering furnace, heating to the temperature of 500 DEG C by a speed of 2 DEG C/min, insulating for 2 hours and dumping, then heating to the temperature of 1400 DEG C at the speed of 4 DEG C/min and insulating for 4 hours, and then cooling in furnace to the room temperature to obtain the required leadless piezoelectric ceramics. The leadless piezoceramic material has high dielectric and piezoelectric performance at quasi four-phase point, the relative dielectric constant of the material can reach 75000 which is 6-7 times of the dielectric constant of pure barium titanate at the Curie temperature, the piezoelectric coefficient d33 can reach 697pC/N which is 5 times of the room temperature piezoelectric coefficient of the pure barium titanate, and the data can be the highest data in that of the leadless piezoceramic material.

The invention relates to a preparation method of barium titanate hollow nanospheres. The method adopts an improved direct precipitation method and comprises the following steps: preparing a mixture of titanium salts and n-butyl alcohol/ethanol of a certain proportion and a barium ion solution as reaction materials, adding alkali liquor of a appropriate concentration to promote crystallization, and carrying out low-temperature heating reaction, thus obtaining the barium titanate hollow nanosphere powder with good dispersity. The prepared product is pure cubic crystal phase and has the appearance of the hollow nanospheres, and the granular size and the appearance are uniform.