摘要:
A magnetic recording disc having a high durability and good electromagnetic conversion characteristics which comprises a non-magnetic support and a magnetic layer provided on at least one surface of the support, wherein the magnetic layer comprises magnetic powder, a resinous binder, polishing particles and a lubricating agent, characterized in that the polishing particles have a Mohs' scale of hardness of not less than 7 and an average particle size of 0.25 r to 0.75 r (r being the thickness (.mu.m) of the magnetic layer) and the lubricating agent is a fatty acid ester having a melting point of not higher than 10.degree. C.
摘要:
In a memory type insulated gate field effect semiconductor device including a semiconductor layer of one conductivity type, a source region of the opposite conductivity type formed in the surface of the semiconductor layer, a drain region of the opposite conductivity type formed in the surface of the semiconductor layer, a gate insulating layer affixed to the surface of the semiconductor layer, and a gate electrode deposited on the surface of the gate insulating layer, the gate insulating layer has a pair of thick gate guarding portions which exist on side of the source and drain regions, and a thin memory portion intermediate between the thick gate guarding portions, and a surface impurity concentration per square centimeter of the semiconductor layer under the thick gate guarding portions is different from a surface impurity concentration per square centimeter of the semiconductor layer under the tin memory portion. The voltage difference between the threshold voltages of the semiconductor device at the memorized state and at the non-memorized state can be increased, and the read-out voltage of the semiconductor device can be reduced. The circuit design is simplified.
摘要:
Disclosed is a brushless motor (1A) which is an axial gap type brushless motor (1A) wherein stators (3A, 4A) comprising a coil (41) and a rotor (2) comprising a permanent magnet (23) are arranged with a gap therebetween in the axial direction. The coil (41) is a band-like wire which is spirally wound such that the width direction of the band-like wire generally coincides with the direction of the magnetic flux that is generated by the permanent magnet (23) of the rotor (2). Consequently, the axial gap type brushless motor (1A) having the above-described structure can be further reduced in eddy current loss in comparison to conventional brushless motors.
摘要:
This heat sink has bonded on one surface a member to be bonded, and has a cooling member in contact with the other surface. The heat sink is provided with a metal plate having a thermal expansion coefficient larger than that of the member to be bonded, and the metal plate is provided with a center portion where the member to be bonded is bonded, and a plurality of linear peripheral slits formed in a whirl-like radial manner such that the linear peripheral slits surround the center portion.
摘要:
The invention is characterized in: forming a magnetic field inside a flow channel tube, the tube wall of which is formed from a material that is nonmagnetic and which, when the pressure outside the flow channel tube is lower than the pressure inside the flow channel tube, passes a portion of the air flowing inside the tube through the tube wall and discharges same to the outside thereof; supplying air to the flow channel tube so that at least a region of laminar flow is formed inside the flow channel tube; and reducing the pressure outside the flow channel tube to a prescribed pressure.
摘要:
Provided is a reactor that enables high inductance to be generated with stability in a wide current range, while minimizing noise, processing cost, and eddy-current loss. The reactor (D1) has the ratio (t/W) of the width (W) to the thickness (t) of a conductive member that composes an air-core coil configured to be 1 or less, and preferably, 1/10 or less. Furthermore, the reactor also has the absolute value of a value ((L1−L2)/L3) that has had: the difference (L1−L2) between; the space interval (L1) between an inner wall face of a first core member (3) and an inner wall face of a second core member (4), at the innermost circumference position of the air-core coil (1); and the space (L2) between the inner wall face of the first core member (3) and the inner wall face of the second core member (4), at the outermost circumference position of the air-core coil (1); divided by an average value (L3); configured to be 1/50 or less. The ratio (R/W) of the radius (R), from the axis-center (O) of the air-core coil (1) to the outer circumference of the air-core coil (1), to the width (W) of the air-core coil (1) (conductive member), is 2=R/W=4.
摘要:
This DC brushless motor (1) is provided with a stator (2) that has exciting coils (31, 32) and a rotor (4) that is positioned coaxially to the stator (2). The stator (2) has a quasi-E-shaped cross-section in the axial direction at the radius part; a plurality of protrusions (212, 222, 232) serving as magnetic poles are formed on the respective 3 parallel sections (211, 221, 231) of the E in the same number in the circumferential direction; and of the magnetic poles (212, 222, 232) formed at the 3 parallel sections (211, 221, 231) of the E, the top and the bottom magnetic poles (212, 232) are respectively positioned so as to be shifted in the opposite directions in the circumferential direction with respect to the center line of the middle magnetic pole (222). Changes in the magnetic resistance between the stator (2) and the rotor (4), which are caused by the flow of a magnetic flux generated around the exciting coils (31, 32), are utilized as a driving force. The DC brushless motor (1) configured in said manner exhibits excellent space efficiency at low cost and is less affected by temperature changes.
摘要:
Disclosed is a brushless motor (1A) which is an axial gap type brushless motor (1A) wherein stators (3A, 4A) comprising a coil (41) and a rotor (2) comprising a permanent magnet (23) are arranged with a gap therebetween in the axial direction. The coil (41) is a band-like wire which is spirally wound such that the width direction of the band-like wire generally coincides with the direction of the magnetic flux that is generated by the permanent magnet (23) of the rotor (2). Consequently, the axial gap type brushless motor (1A) having the above-described structure can be further reduced in eddy current loss in comparison to conventional brushless motors.
摘要:
Provided is a radar apparatus that detects an object, and includes: an oscillating unit for generating carrier waves; first and second transmission units for spreading the carrier waves, respectively using a first pseudo-random code and a second pseudo-random code different from the first pseudo-random code; a first transmission antenna for transmitting the carrier waves spread by the first transmission unit; a second transmission antenna for transmitting the carrier waves spread by the second transmission unit and have a directional characteristic different from that of the carrier waves transmitted by the first transmission antenna; a reception antenna for receiving reflected waves that are the carrier waves that have been transmitted by the first and second transmission antennas and have been reflected from the object; and a reception unit for despreading the reflected waves, using the first pseudo-random code and despreading the reflected waves, using the second pseudo-random code.
摘要:
A method for polishing a wafer effectively preventing a sag in an outer peripheral portion of a wafer and a polishing pad for polishing a wafer preferably used in the method for polishing a wafer are provided. The method for polishing a wafer comprises the step of: mirror-polishing a wafer with a main surface of the wafer being in contact with a polishing pad of non-woven fabric impregnated with resin, wherein a ratio of surface roughness of the polishing pad to compressibility thereof {surface roughness Ra (μm)/compressibility (%)} is 3.8 or more.