134results about How to "Good electromagnetic properties" patented technology

A magnetic recording medium includes, in the following order: a backcoat layer; a nonmagnetic support; a nonmagnetic layer containing a nonmagnetic powder and a binder; and a magnetic layer containing a ferromagnetic powder and a binder, wherein the backcoat layer contains particles having an average primary particle size D50 of from 0.05 to 1.0 μm and forming substantially no aggregates nor agglomerates in the backcoat layer.

The magnetic tape has a magnetic layer and a backcoat layer, wherein, each of the magnetic layer and backcoat layer contains a fatty acid ester, the Ra measured on the magnetic layer side surface is less than or equal to 2.8 nm, the difference between the spacing measured by optical interferometry on the magnetic layer side surface after and before vacuum heating is greater than 0 nm but less than or equal to 8.0 nm, the FWHM_before on the backcoat layer side surface is greater than 0 nm but less than or equal to 10.0 nm, the FWHM_after on the backcoat layer side surface is greater than 0 nm but less than or equal to 10.0 nm; and the difference between the spacing measured on the backcoat layer side surface after and before vacuum heating is greater than 0 nm but less than or equal to 8.0 nm.

The magnetic tape has a magnetic layer containing ferromagnetic powder and binder on a nonmagnetic support, wherein the centerline average surface roughness Ra as measured on the surface on the magnetic layer side of the magnetic tape is less than or equal to 1.8 nm, and the logarithmic decrement as determined by a pendulum viscoelasticity test on the surface on the magnetic layer side of the magnetic tape is less than or equal to 0.050.

The present invention relates to a magnetic recording medium comprising a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. The magnetic layer has a thickness ranging from 30 to 130 nm, and a glossiness of the magnetic layer surface ranges from 155 to 270 percent.

A magnetic recording medium is disclosed, which comprises a support having thereon a magnetic layer comprising a binder and a ferromagnetic powder dispersed therein, wherein said binder comprises a polyurethane resin having at least one cyclic hydrocarbon group and at least one ether linkage, and said ferromagnetic powder is a ferromagnetic metallic powder which comprises Fe and has a mean major-axis length of from 0.05 to 0.19 .mu.m and a crystallite size of from 100 to 230 .ANG.; and further a magnetic recording medium is disclosed, comprising a support having thereon in succession an undercoat layer comprising a binder U and an inorganic powder dispersed therein and a magnetic layer comprising a binder M and a ferromagnetic powder dispersed therein, wherein at least either of the binder U or M comprises a polyurethane resin having at least one cyclic hydrocarbon group and at least one ether linkage and said ferromagnetic powder is a ferromagnetic metallic powder which comprises Fe and has a mean major-axis length of from 0.05 to 0.19 .mu.m and a crystallite size of from 100 to 230 .ANG..

The invention relates to a nested type Koch fractal Beidou dual-frequency micro-strip antenna which comprises a high dielectric constant dielectric substrate, a good conductor grounding reflection plate and an N type or sma national standard joint, a structural mode of copper axis feed is adopted, metal good conductors are coated on two faces of the high dielectric constant dielectric substrate, a nested type ring outer Koch fractal paster and a nested type ring inner Koch fractal paster are arranged on the upper surface of the high dielectric constant dielectric substrate, and a gap groove structure is arranged between the ring outer Koch fractal paster and the ring inner Koch fractal paster. A low-frequency stage feed hole is formed in the ring outer Koch fractal paster, a high-frequency stage feed hole is formed in the ring inner Koch fractal paster, and four gap grooves are formed in the good conductor grounding reflection plate. The nested type Koch fractal Beidou dual-frequency micro-strip antenna has the advantages of being novel in structure, small in size, good in radiation characteristic, small in effect of environment factor, low in cost, easy to integrate and the like, and can meet the requirement of a Beidou satellite communication system for an antenna.

The magnetic tape has a magnetic layer containing ferromagnetic powder and binder on a nonmagnetic support, wherein a timing based servo pattern is present on the magnetic layer, the centerline average surface roughness Ra that is measured on the surface of the magnetic layer is less than or equal to 1.8 nm, and the coefficient of friction that is measured on the base portion of the surface of the magnetic layer is less than or equal to 0.35.

Provided is a magnetic recording medium having excellent surface smoothness and coating durability. The magnetic recording medium comprises an undercoating layer comprising a radiation-curing resin as a main component and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. The undercoating layer comprises no particulate matter, and the magnetic layer comprises a diamond powder.

The invention discloses a sendust magnetic powder core. Magnetic powder adopted for the sendust magnetic powder core comprises, by weight, 9-10% of Si, 5-6% of Al, and the balance Fe. Based on the ratio, the sendust magnetic powder core is prepared through powder pre-annealing, screening, passivation, insulation coating, compression moulding forming and heat treatment. According to the sendust magnetic powder core, the sendust magnetic powder core preparing technology is optimized, each preparation step is controlled, and excellent comprehensive performance is realized through the cooperation of all the steps.

The present invention relates to a magnetic recording medium comprising a magnetic layer comprising a hexagonal ferrite powder and a binder on one surface of a nonmagnetic support and a backcoat layer on the other surface of the nonmagnetic support. A power spectrum density at a pitch of 10 micrometers ranges from 800 to 10,000 nm³ on the magnetic layer surface, a power spectrum density at a pitch of 10 micrometers ranges from 20,000 to 80,000 nm³ on the backcoat layer surface, the magnetic layer has a center surface average surface roughness Ra, as measured by an atomic force microscope, ranging from 0.5 to 2.5 nm, and the hexagonal ferrite powder has an average plate diameter ranging from 10 to 40 nm.

Disclosed is a magnetic recording medium comprising a magnetic layer on a surface of a flexible support and a backcoat layer on the opposite surface, characterized in that the backcoat layer comprises a granulated oxide consisting of titanium oxide, alpha-iron oxide or a mixture thereof and carbon black in the weight ratio ranging from 60/40 to 90/10, and further comprises a binder in an amount ranging from 10 to 40 parts by weight with respect to 100 parts by weight of the total amount of the granulated oxide and carbon black. The magnetic recording medium of the present invention is characterized in that both the running durability and electromagnetic characteristics are excellent.

The soft magnetic structural steel plate with excellent welding performance has very low C content, Si content of 1.45-1.65 wt%, medium Mn content, alloyed Ni and Cr, Ti content of 0.008-0.016 wt%, N content controlled to be lower than 0.0055 wt%, Ca or RE treatment, and optimized rolling and post-treatment process. It has excellent mechanical performance, good electromagnetic performance, excellent welding performance, excellent low temperature impact toughness, and capacity of being used in cold area.

The present invention relates to soft magnetic structural steel, and is especially one kind of soft magnetic structural steel resisting salt fog and its making process. The present invention solves the technological problem of raising the salt fog corrosion resistance of soft magnetic structural steel. The soft magnetic structural steel consists of C 0.020-0.040 wt%, Si 1.40-1.60 wt%, Mn 0.40-0.80 wt%, P not more than 0.015 wt%, S not more than 0.005 wt%, Als 0.040-0.060 wt%, Cu 0.20-0.50 wt%, Ti 0.035-0.055 wt%, N not more than 0.0035 wt%, Ni 0.80- 1.20 wt%, and Ca or REM 10-60ppm, except Fe and inevitable impurities. Its making process includes continuous casting, re-crystallization controlling rolling, accelerated cooling or intermittent direct quenching, and subsequent slow cooling step. The present invention is especially suitable for use as side guide plate in magnetic suspension train track beam in high salt fog area.

The present invention provides a magnetic recording medium comprising an undercoating layer comprising a radiation-curable compound that has been cured by irradiation with radiation, a nonmagnetic layer comprising a nonmagnetic powder and a binder, and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support, wherein the magnetic layer and/or the nonmagnetic layer comprise a carbonic ester denoted by general formula (1), and the undercoating layer has an indentation hardness lower than that of the nonmagnetic support.

In general formula (1), each of R¹ and R² independently denotes a saturated hydrocarbon group, with a total number of carbon atoms in R¹ and R² being equal to or higher than 12 but equal to or lower than 50.

A magnetic recording medium comprising a magnetic layer, a support and a backing layer in this order, wherein the backing layer comprises a binder and an inorganic powder having a surface covered with an electrically conductive substance.

Provided is a magnetic recording medium having excellent dispersibility, smoothness and electromagnetic characteristics. The magnetic recording medium comprises at least one magnetic layer comprising a ferromagnetic powder and a binder on a nonmagnetic support. Said ferromagnetic powder is a ferromagnetic metal powder having an average major axis length of 10 to 80 nm and a crystallite size of 8 to 18 nm, or a ferromagnetic hexagonal ferrite powder having an average plate diameter of 5 to 40 nm, and said binder comprises 0.2 to 0.7 meq/g of at least one polar group selected from —SO₃M, —OSO₃M, —PO(OM)₂, —OPO(OM)₂ and —COOM (where M denotes a hydrogen atom, alkali metal or ammonium salt), and/or 0.5 to 5 meq/g of at least one polar group selected from —CONR₁R₂, —NR₁R₂ and —NR₁R₂R₃⁺ (where R₁, R₂ and R₃ independently denote hydrogen atoms or alkyl groups).

A method for producing a cage rotor for an asynchronous machine is provided. The method includes providing a rotor body having a conductor bar segment in which conductor bars are provided, producing conductor bar slots in the conductor bar segment, wherein one conductor bar slot is provided for each of the conductor bars and producing short circuit ring recesses for short circuit rings, wherein the conductor bar slots each open into the short circuit ring recesses, pressure die casting cage material in the conductor bar slots, in situ, so that the conductor bars are formed of the conductor bar material in the conductor bar slots and the short circuit rings are formed in the short circuit ring recesses, and generating an area in the conductor bar material and the rotor body material including a metallurgical bond between the conductor bar material and the rotor body material at interfaces between the conductor bars and the rotor body.

The invention provides a preparation method of core-shell magnetic microspheres, and belongs to the technical field of functional material preparation. The preparation method comprises the steps thatfirstly, monodispersed phenolic aldehyde microspheres or monodispersed silicon dioxide phenolic aldehyde core-shell microspheres are synthesized; then the microspheres and ferric salts are dispersed in a mixing solvent containing glycerinum and isopropanol, added into a hydrothermal reaction still for an airtight high-pressure solvothermal reaction, and a phenolic aldehyde microsphere/glycerinum ferric core-shell structure product or a silicon dioxide/phenolic aldehyde/glycerinum ferric core double-shell structure product are correspondingly obtained; and finally, the phenolic aldehyde microsphere/glycerinum ferric core-shell structure product is calcined in an inert atmosphere in a tube furnace to form carbon/ferroferric oxide core-shell magnetic microspheres, and the silicon dioxide/phenolic aldehyde/glycerinum ferric core double-shell structure product is subjected to high-temperature calcination and alkali etching by inert gas to obtain hollow carbon/ferroferric oxide double-shellmicrospheres. The preparation method is simple, magnetic nanosheets and carbon are compounded successfully, the electromagnetic property of the magnetic nanosheets is improved, the nanosheets adoptedon an outer layer can effectively inhibit a skin effect, the prepared products have the excellent electromagnetic property, and the preparation method of the core-shell magnetic microspheres can be used for electromagnetic wave absorption and shielding fields.

This invention discloses an antenna of a book electronic certificate read-write device composed of an upper antenna conductor loop, an upper antenna conductor loop, an impedance match network connected with them, a RF connector connected with the impedance match network, a lower antenna base board and an upper antenna base board, in which, a metal antenna coil starts from the RF connector to circle around one or many times to come back to the connector again, and the impedance match network part is composed of resistors and capacitors, which can read non-contacted IC chips of multiple regions in certificates at the same time and avoids interference among antennas.

The invention discloses an all-directional wideband antenna which has the same shape with an installation surface structure; the all-directional wideband antenna comprises a coaxial feed joint, a cylindrical back chamber (1), a glass fiber reinforced plastic cover (2), a metal upper cover (3), a metal lower cover (7), a sleeve (8), three groups of short circuit columns and three supporting frames; three groups of short circuit columns are arranged between the metal upper cover (3) and the metal lower cover (7); the three supporting frames are arranged on the internal wall of the sleeve (8) which is welded inside the cylindrical back chamber (1) and is positioned at the jointing of a conical bottom surface (101) and a transition section (103); the glass fiber reinforced plastic cover (2) is arranged on a flange platform (104) of the cylindrical back chamber (1); the frontal disc (35) of the metal upper cover (3) is attached to the glass fiber reinforced plastic cover (2); the frontal disc (35) of the metal upper cover (3) is attached to the glass fiber reinforced plastic cover (2), thus leading the all-directional wideband antenna to be internally embedded into the installation plane of a movable platform so as to form the structural conformality.

The invention belongs to the technical field of electromagnetic wave-absorbing and electromagnetic shielding materials, and discloses a high-efficiency wave-absorbing ultrathin carbon fiber reinforcedcomposite material and a design optimization method thereof, the high-efficiency wave-absorbing ultrathin carbon fiber reinforced composite material is composed of two layers of carbon fiber reinforced planar structures; in each layer, periodically arranged fiber arrays with fiber axes parallel to each other are embedded into a ceramic matrix, and the ceramic matrix is used for combining fibers together and providing necessary mechanical or chemical properties; two layers of a planar structure are stacked, fibers of different layers are axially oriented in different directions to form a sheetcomposite structure, and the composite structure can be further stacked in parallel to provide a whole laminated structure material. According to the material, a continuous conductive network can beprovided to effectively absorb electromagnetic waves; optimized electromagnetic characteristics are realized; the microwave absorption efficiency is improved; periodically embedding the fibers into the ceramic matrix helps to improve the mechanical properties of the laminate and increase microwave absorption.