173 results about "Zero field" patented technology

A high-stability magnetic rheopectic liquid is prepared from the magnetic suspended phase including reduced and phosphonated carbonyl iron powder, liquir carrier, nano-class inorganic bentonite or silica oxide-type thixotropic agent and surfactant through cleaning the surface of suspended particles, activating and synthesizing the magnetic rheopectic liquid. Its advantages are high stability without deposition, better antiwear nature, zero field viscosity and ideal rheopectic characteristics.

The invention discloses a rotation sensor suitable for gear wheels. MR (magneto-resistive) sensors are placed inside a zero field region generated by at least two permanent magnets. Said sensors are divided into two groups that are immersed in different locally generated magnetic environments. A differential signal taken between the two groups then senses the movement of the wheel's teeth. A single wafer method for manufacturing the device is also briefly described.

The invention relates to a magnetic rheological polishing fluid and a preparing method for the fluid. The magnetic rheological polishing fluid comprises by volume magnetic particles 30-40%, pure water 45-55%, additive 5-10%, surface active agent 3-5% and polishing powder 5-8%. The preparing method comprises: the magnetic particles are surface cleaned and activated, the surfaces of the magnetic particles are treated by a hi-speed ball pulverizer. The magnetic rheological polishing fluid prepared by the invention is of hydrolyzation function. The preparing method is simple. The fluid is of a good resistance to settlement and conglobation, low zero-field viscosity, high polishing efficiency, good effect, long service life, and is applicable for optic polishing. The invention solves such problems of prior magnetic rheological polishing fluid as high viscosity, weak magnetizing strength, liable to caking, not stable in settling and conglobation, liable to rust, short service life and low efficiency. The magnetic rheological polishing fluid prepared by the invention is of high efficiency, and can facilitate the surface finish of a k9 glass to increase from 400nm to 0.6 nm in 30 minutes. The invention can be widely used in the super surface polishing of optic glass.

A well-posed magnetic imaging method is disclosed that exploits the non-linear behavior of the characteristic time scale of the Neel relaxation for obtaining accurate high-spatial resolution images of magnetic tracers. The method includes placing an object in a selection field (static field) generated by three pairs of orthogonally arranged coil (drive coils), supplying prudently choice currents to the drive coils, a zero field voxel (ZFV) is formed that can be positioned anywhere in the local region of interest (ROI), switching the magnetizing field off, and collecting an image.

The invention relates to the field of intelligent magnetic materials and in particular relates to a graphene @Fe3O4 compound water base magnetorheological fluid and a preparation method thereof, solving the problems that existing magnetorheological fluids are easy to settle and the stability and magnetorheological effects of the magnetorheological fluids are difficult to optimize at the same time. The preparation method comprises the following steps: preparing a Fe3O4 water base magnetic fluid with FeCl2.4H2O and FeCl3.6H2O; sequentially adding concentrated sulfuric acid, potassium permanganate and hydrogen peroxide to natural flake graphite and sodium nitrate to prepare graphite oxide; and then carrying out ultrasonic dispersion on home-made graphite oxide to prepare graphene oxide, finally adding a surfactant, the Fe3O4 water base magnetic fluid and a reducing agent to graphene oxide, washing the solution with deionized water until the solution is neutral, and then dispersing graphene @Fe3O4 compound magnetic particles in the deionized water to undergo ultrasonic dispersion, removing the precipitates and taking the supernatant, namely the stable graphene @Fe3O4 compound water base magnetorheological fluid, wherein the magnetic particles are graphene @Fe3O4 and account for 5-35wt% of the whole. The method has the advantages of good stability, low zero field viscosity, high shear strain and wide operating temperature range.

A method comprising introducing an injected gas (e.g., Argon, Xenon) into a beam line region comprising a magnetic scanner is provided herein. The injected gas improves beam current by enhancing (e.g., increasing, decreasing) charge neutralization of the magnetic ion beam (e.g., the ion beam at regions where the scanning magnetic field is non-zero) thereby reducing the current loss due to the zero field effect (ZFE). By reducing the current loss in regions having a magnetic field, the magnetic beam current is increased (e.g., the beam current is increased in regions where the magnetic field is non-zero) raising the overall beam current in a uniform manner over an entire scan path and thereby reducing the effect of the ZFE. In other words, the ZFE is removed by effectively minimizing it through an increase in the magnetized beam current.

The invention discloses an impeller magneto rheological fluid brake for a vehicle. The fluid brake consists of a shell, a braking impeller, an electromagnetic device, a bearing shaft, a conical roller bearing, a sealing ring, an end cover and an auxiliary electromagnetic clutch, wherein the electromagnetic device comprises a magnet exciting coil and a magnet insulating copper sleeve; a half shaft on a driving wheel or a steering joint on a non-driving wheel can be taken as the bearing shaft; blades with rectangular sections are distributed on the peripheries of both sides of a disk of the braking impeller; the auxiliary electromagnetic clutch consists of a driving disk, a driven disk and a middle disk which consists of two branch disks transversely crossing the brake shell; the two branch disks are connected through a guide shaft, and form a conjugate friction pair together with the driving and driven disks of the clutch; and the closing and opening states of the conjugate friction pair are controlled by using the resultant force of the pre-tightening force of pre-tightening spring groups on both sides of the shell and the electromagnetic force of the clutch, so that zero-field loss of a magneto rheological fluid can be effectively avoided by using the brake during normal running of the vehicle, the real-time, active and continuous ABS (Antilock Brake System) braking process of the vehicle can be realized during braking, and a braking control process with higher performance than that of a hydraulic mechanical braking system is realized on a low-adhesion road surface.

The invention discloses a magnetorheological damper having parallel normally-open holes and methods for calculating zero-field damping coefficient, on-field damping coefficient and damping force of the magnetorheological damper. The magnetorheological damper comprises a cylinder, a piston is slidably disposed inside the cylinder, a piston rod is disposed at one end of the piston, the piston rod extends out of one end opening of the cylinder, the piston comprises a core, the sidewall of the core is provided with at least one circular groove in a recessed manner, an excitation coil is wound in each circular groove, a magnetic-shielding protective ring covers the outside of each excitation coil, and magnetic permeability protective rings cover the sidewall of the core, a gap between the magnetic-shielding protective rings and magnetic permeability protective rings and the inner wall of the cylinder forms a circular damping passage in the axial direction, and the core is provided with at least one normally open hole. Under semi-active control of structural vibration, damping force can be controlled for the magnetorheological damper just by switching zero current and maximum current according to a switch control strategy, establishment and solution of a complex reverse mechanical model are avoided, and the control process is simple and practical.

The invention relates to a bistable composite film of polymer dispersed liquid crystals and a manufacturing method thereof. The composite film is composed of two pieces of flexible transparent conducting film and a layer of polymer dispersed liquid crystals, wherein, the two pieces of flexible transparent conducting film are etched with a coplanar conversion electrode; the layer of polymer dispersed liquid crystals is highly active polyurethane acrylic ester; the liquid crystals are nematic phase liquid crystal molecules with large birefringence. When imposing a coplanar horizontal electric field, the bistable composite film of the polymer dispersed liquid crystals is in closed and scattering state and still keeps the scattering state after the electric field is eliminated; when imposing a coplanar comb-shaped electrode short-circuit on an opposite electric field, the bistable composite film of the polymer dispersed liquid crystals is in open and transparent state and still keeps the transparent state after the electric field is eliminated. The bistable composite film of the polymer dispersed liquid crystals has the manufacturing method that: after being mixed, the highly active polymer and the nematic phase liquid crystals with the large birefringence are separated to form the structure that the polymer wraps crystal liquid droplets. The invention uses the simple design proposal and depends on changing the direction of the electric field to realize zero field stability of the polymer dispersed liquid crystals so as to further acquire an electronic-paper technology with better energy conservation; or the bistable composite film of polymer dispersed liquid crystals can be specially applied to the fields of building decoration and jewelry counters and so on as a dimming function film which is clipped in glass.

The invention relates to a polymer dispersed liquid crystal electronic paper and a manufacturing method thereof. A composite film is constituted by two transparent flexible conductive films and a polymer dispersed liquid crystal layer, wherein, electrodes are etched on the two flexible transparent conductive films. A polymer is modified polyurethane acrylate which is added by a surfactant and lecithin, and liquid crystal is dielectric switching liquid crystal material which is the mixture of 20 percent biphenyl ester and 80 percent difluoro diphenylacetylene or the product with the same series. When a low-frequency electric field is imposed on the polymer dispersed liquid crystal electronic paper, the polymer dispersed liquid crystal electronic paper is in the transparent open state, and the transparent open station is still maintained after removing the electric field; when a high-frequency electric field is imposed, the polymer dispersed liquid crystal electronic paper is in the scattering closed state, and the scattering closed state is still maintained after removing the electric field. The manufacturing method of the polymer dispersed liquid crystal electronic paper is to form the weak anchoring polymer which is packaged by a dielectric switching liquid crystal droplet structure by separating after mixing the weak anchoring polymer with the dielectric switching liquid crystal. The manufacturing method combines the natures of the weak anchoring polymer and the dielectric switching liquid crystal with the dual-frequency drive of low-frequency writing and high-frequency erasing so as to realize the stable zero-field of the polymer dispersed liquid crystal, thereby obtaining the new electronic paper technology or being applied as a new product of dimming glass.

The invention discloses a hexagonal ferrite material with high anisotropy and low ferromagnetic resonance line width and a preparation method and belongs to the technical field of preparation of ferrite materials. The material is prepared from a main component and a dopant and is characterized in that the main component comprises 67.0mol%-75.0mol% of Fe2O3, 0.5mol%-7.5mol% of SrCO3, 0.5mol%-7.5mol% of BaCO3, 3.5mol%-6.5mol% of Co2O3, 3.5mol%-11.5mol% of La2O3 and 8.5mol%-13.5mol% of CuO; the dopant comprises, in percentage by weight of the main component in terms of oxide, 0.5wt%-2.0wt% of Bi2O3, 0.15wt%-1.0wt% of B2O3, 0.02wt%-0.32wt% of CaCO3, 0.02wt%-0.32wt% of SiO2 and 0.05wt%-0.50wt% of ISOBAM. The ferrite material has the characteristics of high density d larger than 5.20 g/cm<3>, high remanence 4 phi Mr larger than 4.3 kGs, high anisotropic field Ha larger than 15.0 kOe and low ferromagnetic resonance line width delta H smaller than 3,700 e (@44 GHz and Zero field).

The invention discloses a pre-bunching high-power gyro traveling wave tube amplifier and relates to a microwave source device technology, comprising three sections: a linear amplifying section which adopts loss loading metal waveguide; an inertial drifting section which adopts heavy loss loading over-mode waveguide to provide an inertial bunching space approximating zero field for a bunching electron beam; and a nonlinear amplifying section which adopts smooth metal waveguide, wherein the gyro electron beam is fully modulated by driving power in the linear section; the modulated electron beam obtains good bunching characteristic according to inertia in the inertial drifting section; and the electron beam with good bunching vehemently reacts with an operating mode in the nonlinear amplifying section and transforms transverse kinetic energy to microwave energy to obtain high-energy microwave output. Both the linear amplifying section and the inertial drifting section are loss loops to guarantee the stability of the device; and the nonlinear amplifying section adopts the pre-bunching electron beam to work, and has the advantages of high power, high stability, and high efficiency.

In the invention, a route lookup method is to extract keyword from the received message, compresses the keyword by compressing zero-field into at least one mark bit, and accordingly looks up the route table. This invention improves lookup speed greatly.

The invention discloses a measurement method and measurement system of zero-field paramagnetic resonance. According to the measurement method, a paramagnetic resonance spectrum of target electrons ismeasured by utilizing an NV color center in a diamond base material as a probe; a zero-field condition is utilized, adverse effects caused by molecule random orientation can be resisted and the Zeemaneffect generated by an external electric field can be eliminated, so that a needed energy grade structure is directly detected. For example, a space structure of a molecule can be obtained through analyzing an electron-electron fine interaction effect; a local polar environment of the molecule can be obtained through analyzing an electron-nuclear spin superfine interaction effect; a precision displacement device, an optical co-focusing device and an NV color center probe are combined, and the precision displacement device and a co-focusing microscopic device can realize accurate finding and detection of the NV color center; the NV color center is a single-electron probe and has a nano-scale resolution capability, so that a nano-scale detection capability is realized.

The present invention relates to a liquid crystal display, more specifically, to a single layer reflective full color cholesteric display employing full spectrum circularly polarization. The display has not only zero-field long time memory but also paper-like super high brightness and contrast.

Method, apparatus, and program means for shuffling data. The method of one embodiment comprises receiving a first operand having a set of L data elements and a second operand having a set of L control elements. For each control element, data from a first operand data element designated by the individual control element is shuffled to an associated resultant data element position if its flush to zero field is not set and a zero is placed into the associated resultant data element position if its flush to zero field is not set.

The invention relates to the field of intelligent magnetic materials and in particular relates to a graphene @Fe3O4 compound organic magnetorheological fluid and a preparation method thereof, solving the problems that existing magnetorheological fluids are easy to settle and the stability and magnetorheological effects of the magnetorheological fluids are difficult to optimize at the same time. The preparation method comprises the following steps: adding an organic solvent to FeCl2.4H2O and FeCl3.6H2O to prepare a Fe3O4 organic magnetic fluid; adding cellulose or imidazole to the organic solvent to prepare a homogeneous solution, then adding expanded graphite and carrying out ultrasonic dispersion to prepare a graphene organic solution; finally adding a surfactant, the Fe3O4 organic magnetic fluid and an organic radical carrier fluid to the graphene organic solution and carrying out ultrasonic dispersion, thus obtaining the stable graphene @Fe3O4 compound organic magnetorheological fluid, wherein magnetic particles are graphene @Fe3O4 and account for 10-30wt% of the graphene @Fe3O4 compound organic magnetorheological fluid. The method has the advantages of good stability, low zero field viscosity, high shear strain and wide operating temperature range.

A modulator is formed of a semiconductor material which utilises the electro-optic effect to achieve a change in the refractive index Δn of the material under the influence of an applied electrical field F (251), in accordance with the equation: Δn=−½ n₀³ [rF+sF²]≡Δn_L+Δn_Q where n₀ is the refractive index of the material at zero field, and Δn_L and Δn_L and Δn_Q are the linear and quadratic contributions to the change in refractive index respectively, r is the linear electro-optic coefficient of the material and s is the quadratic electro-optic coefficient of the material incorporating a plurality of quantum dots and operating in a wavelength region where the value of rF is sufficiently greater than the value of sF² so as to operate with the dominant effect on the refractive index Δn being contributed by the linear effect. In this way, a device with a wide bandwidth is achieved by appropriately separating the band-gap wavelength (λ_g) and the operating wavelengths (λ).

The invention discloses a core-shell metal oxide/titanium oxide compound electrorheological fluid and a preparation method thereof. A non-spherical metal oxide is taken as a core, a titanium oxide polar molecular layer is coated, and the metal oxide and titanium oxide coact with each other, so that the electrorheological performance of a compound material is enhanced; the obtained compound material has an anisotropic nanostructure; and the obtained electrorheological fluid has the advantages of low zero field strength, high high-field strength and high suspension stability.