119 results about "Magnetic stability" patented technology

The invention relates to the technical field of preparation of environment functional materials, in particular to a magnetic composite material surface imprinting thermosensitive adsorbent, and a preparation method and the application thereof. The method comprises the following steps that: firstly, a ferroferric oxide/nerchinskite nanotube magnetic composite material is prepared by a solvent thermal synthesis method; secondly, the magnetic composite material is modified on ethenyl by using 3-(methacrylo) propyltrimethoxyl silane; and finally, the nerchinskite nanotube magnetic composite material is prepared by using the ethenyl-modified magnetic composite material as a substrate material, 2, 4, 5-trichlorophenol as a template molecule, methacrylate as a functional monomer, N-isopropylacrylamide as a thermosensitive functional monomer, ethylene glycol dimethacrylate as a cross-linking agent, and 2,2'-azodiisobutyronitrile as an initiator. The prepared thermosensitive imprinting adsorbent is obvious in thermal stability and magnetic stability, sensitive in magnetic effect and thermosensitive effect, relatively high in adsorption capacity, obvious in reversible absorption/release function along with temperature and obvious in tertiary calcium phosphate (TCP) molecule recognition performance.

The invention discloses a cold-heat circulation aging treatment method for increasing magnetic stability of permanent magnets. The method comprises the following steps of: putting one or more permanent magnets magnetized in a saturated manner on a non-magnetic bottom plate; then putting in a high-low temperature chamber, and freezing at minus 70 DEG C to minus 20 DEG C for 30-120 min; then, heating the high-low temperature chamber to 60-250 DEG C at the temperature increasing rate of 1-10 DEG C/min, and keeping the temperature for 30-240 min; and finally, naturally cooling to room temperature, and completing cold-heat circulation aging treatment. By adopting the method disclosed by the invention, total loss, irreversible loss, reversible loss and reversible temperature coefficients when temperature of the permanent magnets is changed can be effectively eliminated or reduced; and heat stability, time stability, magnetic stability and radiation-resistant magnetic stability of the permanent magnets under a vibration condition can be increased.

Current-perpendicular-to-the-plane (CPP), current-in-to-the-plane (CIP), and tunnel valve type sensors are provided having an antiparallel (AP) coupled free layer structure, an in-stack biasing structure which stabilizes the AP coupled free layer structure and a nonmagnetic spacer layer formed between the in-stack biasing layer and the AP coupled free layer structure. The AP coupled free layer structure has a first AP coupled free layer adjacent to the nonmagnetic spacer layer, a second AP coupled free layer, and an antiparallel coupling (APC) layer formed between the first and the second AP coupled free layers. The net moment of the AP coupled free layer structure has an antiparallel edge magnetostatic coupling with the in-stack biasing structure. At the same time, the first AP coupled free layer has an antiparallel exchange coupling with the second AP coupled free layer. By forming the second AP coupled free layer with a thickness greater than a thickness of the first AP coupled free layer, the AP coupled free layer structure has a net magnetic moment in the direction of the second AP coupled free layer moment. The non-magnetic spacer layer is chosen so that first AP coupled free layer has a parallel interlayer (Neel or Orange-peel or positive exchange) coupling with the in-stack biasing structure, so that the interlayer coupling adds to the edge magnetostatic coupling to increase a stability of the AP coupled free layer structure.

Magnetoresistance effect devices for attaining magnetically stability and for reducing a switching magnetic field. One of the ferromagnetic layers of the magnetoresistance effect device has a plane shape in which a width of an end portions is wider than a center portion sandwiched by two end portions. The end portions are not symmetrical with respect to an easy magnetization axis or longer axis of the plane shape of ferromagnetic material layer, but are substantially rotationally symmetrical with a center of the plane shape as a pivot. The plane shape may have an S-shape where its magnetic domain is stabilized and the switching magnetic field is reduced. The manufacturing method uses two linear mask patterns intersecting with each other to form sharp corners of a ferromagnetic tunnel junction. An electron beam (EB) drawing may be used to form the S-shape plane. The magnetoresistance effect devices may be used in a magnetic memory apparatus, such as a random access memory, a personal digital assistance, a magnetic reproducing head, and a magnetic information reproducing apparatus.

The invention provides a method for preparing sludge-based formed magnetic active carbon. The method comprises the steps as follows: sludge is used as a raw material, an activating agent is added for carbonizing and activating the sludge; nano-sized Fe3O4 is used as a magnetic source for magnetizing the sludge active carbon; and sodium carboxymethylcellulose and aluminum salt are composited to an organic-inorganic binding agent, the binding agent and a p-toluenesulfonhydrazide foaming agent are used for uniformly binding powdery magnetic active carbon into a formed magnetic active carbon precursor with abundant pore structures, and finally, the formed magnetic active carbon precursor is heated to obtain the sludge-based formed magnetic active carbon. According to the method, the sludge is used as a main raw material, the resource utilization of the sludge is achieved, the recycling is convenient, and reutilization can be achieved; and further, the sludge-based formed magnetic active carbon has a stable structure and good magnetic stability, and can be widely used in the fields such as sewage treatment, soil pollution treatment and the like.

The invention relates to wastewater treatment method and device, in particular to a magnetic-stability fluidized bed photocatalytic reactor and a method for treating organic wastewater with difficult degradation thereby. The method solves the problems of low photocatalytic quantum, low activity and easy loss of active components existing in the traditional photocatalytic method and comprises the following steps of: feeding the organic wastewater to a reactor through a pump and a liquid inlet, adding a magnetism-loaded photocatalyst to the reactor through a catalyst feeding port, starting a fan to make air pass through a flow buffer and then enter an air distributor and make the magnetism-loaded photocatalyst be in a suspension state; starting Helmholtz coils to generate a magnetic field, opening an ultraviolet lamp when the magnetism-loaded photocatalyst is in the suspension state to degrade the organic wastewater, and then discharging the treated organic wastewater to a second liquid storage tank. The utilization rate of light energy can be improved, and because the magnetism-loaded photocatalyst is in the stable suspension state, the active component loss caused by mutual friction can be reduced; and the device has the advantages of compact structure, mild condition and high utilization rate of the light energy and can operate intermittently and run continuously.

A magnetic head having an in-stack bias structure and a free layer structure. The in-stack bias structure includes an antiferromagnetic layer, and first through fourth antiparallel (AP) pinned bias layers separated by three AP coupling layers. A first spacer layer is positioned above the fourth bias layer of the bias structure. A free layer is positioned above the first spacer layer. The fourth bias layer magnetostatically stabilizes the free layer.

The invention relates to a method for preparing magnetic porous polystyrene microspheres on the basis of suspension polymerization, belonging to the technical field of preparation of environmental functional materials. The method comprises the following steps: synthesizing Fe3O4 magnetic particles by a solvothermal process; and preparing magnetic porous polystyrene microspheres by suspension polymerization by using styrene and divinylbenzene as functional monomers, azodiisobutyronitrile as an initiator and toluene and cyclohexanol as pore-forming agents. The obtained microspheres have abundant pores on the surface, thereby being beneficial to enhancing adsorbability; and the Fe3O4 magnetic particles inside the microspheres have magnetic stability, and can be quickly separated under the action of an external magnetic field. The adsorbent is used in a water environment for selectively adsorbing 2,4-dichlorophenol and 2,6-dichlorophenol. The static adsorption experiment result indicates that the magnetic porous microspheres prepared by the method have the advantages of favorable adsorption capacity, quick adsorption kinetic property and favorable regenerability.

To provide a soft ferrite which has a high saturation magnetic flux density of Bs at a high temperature of 100 DEG C or higher, especially at a temperature of 150 DEG C or so and deteriorates its magnetic properties less (even if sacrificing its low power loss property to some extent) at the above high temperature, especially deteriorates its core loss less, and is superior in magnetic stability. The major composition of ferrite core contains 56 to 57 mol% iron oxide in terms of Fe2O3, 5 to 10 mol% zinc oxide in terms of ZnO, 3 to 6 mol% in terms of NiO, and the residual mol% manganese oxide in terms of (MnO). When the major composition is expressed by: (Zn<2+>a, Ni<2+>b, Mn<2+>c, Mn<3+>d, Fe<2+>e, Fe<3+>f)O4+delta equation (1) (in the equation (1), a+b+c+d+e+f=3, and the relationship delta=a+b+c+(3/2)d+e+(3/2)f-4) the delta value in the equation (1) is in the range 0 <= delta <= 0.001.

The invention provides a one-step method for preparing sludge-based formed magnetic active carbon. The method comprises the steps as follows: sludge is used as a raw material, sludge screened by a 100-200 mesh sieve and self-prepared nano-sized Fe3O4 are uniformly composited in a proportion to form a powdery magnetic active carbon precursor; phenolic resin-silica sol is adopted as a binding agent, the binding agent and an azodicarbonamide foaming agent are used for uniformly binding the powdery magnetic active carbon precursor to form a formed magnetic active carbon precursor with abundant pore structures; and finally, the formed magnetic active carbon precursor is certainly carbonized and activated to obtain the sludge-based formed magnetic active carbon. According to the one-step method, the sludge is used as a main raw material, the resource utilization of the sludge is achieved, the recycling is convenient, and reutilization can be achieved; and further, the sludge-based formed magnetic active carbon has a stable structure and good magnetic stability, and can be widely used in the fields such as sewage treatment, soil pollution treatment and the like.

The invention relates to an X-shaped zeolite molecular sieve and a method for preparing thereof, relating to a field of zeolite molecular sieve material; The X-shaped zeolite molecular sieve is a magnetic iron-doped X-shaped zeolite molecular sieve; magnetic ferroferric oxide is formed in the zeolite lattice, wherein, quality percentage of Fe occupying the molecular sieve is 1.89 percent to 3.48 percent. The preparing method comprises the steps that, iron-doped X-shaped zeolite molecular sieve is firstly compounded and then the magnetized magnetic iron-doped X-shaped zeolite molecular sieve is prepared through hydrogen reduction; the method results in a structure of Fe3O4 formed in frame of the iron-doped X-shaped zeolite molecular sieve. The magnetic iron-doped X-shaped zeolite molecular sieve has strong magnetism and magnetic stability, which not only solves the problem that the existing powdery zeolite molecular sieve is difficult to be recycled in reaction solution, and further improves absorption property of the sieve, but also enlarge application range of the zeolite molecular sieve, thereby allowing the zeolite molecular sieve to be applied to catalytic reaction in which iron acts as the catalyst.

A current-perpendicular-to-the-plane magnetoresistive sensor has an antiparallel free (APF) structure and soft side shields wherein the upper free layer (FL2) of the APF structure is magnetically coupled antiparallel to the top shield and a top shield seed layer via a nonmagnetic antiparallel coupling (APC) layer. In one embodiment the antiparallel coupling is through an antiferromagnetic-coupling (AFC) layer that provides a dominant antiferromagnetic indirect exchange coupling of FL2 to the top shield. In another embodiment the antiparallel coupling is by an APC layer that decouples FL2 and the top shield and causes the edge-induced magnetostatic coupling between FL2 and the seed layer to dominate. The degree of coupling is controlled by the composition and thickness of the nonmagnetic APC layer between FL2 and the seed layer, and by the thickness of the seed layer.

This invention is about a method to make an MRAM element with small dimension, by building an MTJ as close as possible to an associated via connecting an associated circuitry in a semiconductor wafer. The invention provides a process scheme to flatten the interface of bottom electrode during film deposition, which ensures a good deposition of atomically smooth MTJ multilayer as close as possible to an associated via which otherwise might be atomically rough. The flattening scheme is first to deposit a thin amorphous conducting layer in the middle of BE deposition and immediately to bombard the amorphous layer by low energy ions to provide kinetic energy for surface atom diffusion to move from high point to low kinks. With such surface flattening scheme, not only the MRAM element can be made extremely small, but its device performance and magnetic stability can also be greatly improved.

The invention discloses a preparation method for magnetic lignin-based activated carbon. The method comprises the following specific steps: stirring lignin, a chemical activating agent and a magnetic additive with water into paste, and uniformly mixing; after drying, performing carbonization and activation at the temperature of 650-850 DEG C, and then quenching and cooling, wherein the activation time is 0.5-3 hours; washing by sequentially using diluted acid and water until the pH value is 6-8, drying, and finely grinding, so that the magnetic lignin-based activated carbon is obtained. According to the invention, the combination of a oriented preparation technology and a magnetic functionalization technology for the activated carbon can be realized through a simple and convenient one-step preparation process, the used activating agent is environment-friendly, and the obtained magnetic activated carbon is large in specific area and excellent in adsorptive property, and has sufficient magnetic intensity and magnetic stability.

The present invention belongs to the technical field of rotation speed, acceleration speed measurement and inertial navigation, and relates to a quantum inertial sensor capable of measuring six-parameter inertial parameters and a measuring method thereof. The quantum sensor capable of measuring the six-parameter inertial parameters comprises two-dimensional microcrystalline glass vacuum chambers, a three-dimensional microcrystalline glass vacuum chamber, differential pumping tubes and alkali metal sources, the two two-dimensional microcrystalline glass vacuum chambers are connected with three-dimensional microcrystalline glass vacuum chamber by the differential pumping tubes, and respectively with the alkali metal sources, in addition, and the differential pumping tubes are prepared from microcrystalline glass same as the material of microcrystalline glass of the two-dimensional microcrystalline glass vacuum chambers and the three-dimensional microcrystalline glass vacuum chamber. By use of a scheme of counter-throwing of cold atomic groups and combination of manipulation of the cold atomic groups by Raman beams in different directions, and measurement of six-axis-space inertial parameters can be achieved. Based on low-temperature bonding technique, microcrystalline glass is used for constructing the vacuum chambers, so that the quantum inertial sensor has better light transmitting property, is more compact in structure, higher in thermal and magnetic stability and impact resistance, and more conducive to miniaturization.

Disclosed is a method for designing a superconducting magnet for generating high magnetic fields with high uniformity for controlling a stray field to be within an allowable range and acquiring structural and magnetic stability by optimizing the arrangement of positions and shapes of coils configuring the superconducting magnet. Volumes of a main coil and a shielding coil are set to be variables, and the critical value of a wires related on the current and magnetic field, the heat transfer depth, and the quench strain are defined to be restriction conditions so that linear programming is applied to determine an initial shape of the shielding coil and division of the main coil based on the sum of total volumes, that is, an objective function. The initial shapes of the main coil and the shielding coil determined through the linear programming are revised and the shape of a shimming coil is determined by using non-linear programming based on the objective function.

The invention, which belongs to the technical field of acceleration measurement, relates to a microcrystalline-glass-cavity-based movable gravity measurement apparatus. The movable gravity measurement apparatus comprises a two-dimensional microcrystalline-glass vacuum cavity, a three-dimensional microcrystalline-glass vacuum cavity, an alkali metal source, and a differential pump tube. The two-dimensional microcrystalline-glass vacuum cavity is connected to one side of a three-dimensional cooling vacuum cavity of the three-dimensional microcrystalline-glass vacuum cavity by the differential pump tube; a suction device is connected to the other side of the three-dimensional cooling vacuum cavity; and the alkali metal source is connected to the two-dimensional microcrystalline-glass vacuum cavity. Besides, the differential pump tube is made of the same microcrystalline-glass material as those of the two cavities. According to the gravity measurement apparatus, the vacuum cavities are constructed by using the microcrystalline-glass materials based on the low-temperature bonding technology, so that the light transmission property is good, the structure is compact, the thermal and magnetic stability and the anti-impact capability are high. The engineering practicability of the high-precision and high-reliability movable gravity measurement apparatus can be realized conveniently.