Abstract: A magnetic disk apparatus includes a disk and a controller. The disk includes a plurality of tracks including a first track and a second track that is different from the first track. A plurality of data sectors are located on the tracks. The data sectors include short data sectors and long data sectors, each including a plurality of short data sectors. If the controller accesses a long data sector located at an end of the first track, the controller first accesses a short data sector of the long data sector at the end of the first track, and then accesses a short data sector of the long data sector at the beginning of the second track.

Abstract: A layered body having a single crystal layer including a group III nitride having a composition AlxGayInzN (wherein, X, Y and Z are rational numbers respectively satisfying 0.9?X?1.0, 0.0?Y?0.1, 0.0?Z?0.1, and X+Y+Z=1.0) on a sapphire substrate. The layered body includes an initial single crystal layer that includes the group III nitride composition, an oxygen concentration of 1×1020 cm?3 or more and 5×1021 cm?3 or less and a thickness of 15 nm or more and 40 nm or less on the sapphire substrate and a second group III nitride single crystal layer including the group III nitride composition and having a reduced oxygen concentration than the initial single crystal layer.

Abstract: According to one embodiment, a magnetic disk apparatus includes an RW channel with an internal memory for processing data to be read/written from/to a magnetic disk, a transfer controller for controlling data transfer between a host apparatus and the RW channel, and a processor for controlling the RW channel and transfer controller. The processor reads, from the magnetic disk, predetermined area data including to-be-rewritten data, subjects the read predetermined area data to error correction processing in the RW channel, and stores resultant data in the internal memory. The processor rewrites, with rewrite data from the host apparatus, the to-be-rewritten data of the predetermined area data stored in the internal memory to update the predetermined area data, adds an error correction code to the updated data in the RW channel module, and writes resultant data to the magnetic disk.

Abstract: According to one embodiment, a magnetic disk apparatus includes an RW channel with an internal memory for processing data to be read/written from/to a magnetic disk, a transfer controller for controlling data transfer between a host apparatus and the RW channel, and a processor for controlling the RW channel and transfer controller. The processor reads, from the magnetic disk, predetermined area data including to-be-rewritten data, subjects the read predetermined area data to error correction processing in the RW channel, and stores resultant data in the internal memory. The processor rewrites, with rewrite data from the host apparatus, the to-be-rewritten data of the predetermined area data stored in the internal memory to update the predetermined area data, adds an error correction code to the updated data in the RW channel module, and writes resultant data to the magnetic disk.

Abstract: There is provided a method capable of obtaining an aluminum-based group III nitride crystal layer having a smooth surface and high crystallinity by employing only HVPE in which inexpensive raw materials can be used to reduce production costs and high-speed film formation is possible without employing MOVPE. To produce a group III nitride crystal by HVPE comprising the step of growing a group III nitride crystal layer by vapor-phase growth on a single crystal substrate by contacting the heated single crystal substrate with a raw material gas containing a group III halide and a compound having a nitrogen atom, the group III nitride crystal is grown by vapor-phase growth on the single crystal substrate heated at a temperature of 1,000° C. or more and less than 1,200° C. to form an intermediate layer and then, a group III nitride crystal is further grown by vapor-phase growth on the intermediate layer on the substrate heated at a temperature of 1,200° C. or higher.

Abstract: According to one embodiment, a storage control apparatus includes a first buffer controller and a second buffer controller. The first buffer controller is configured to store data of a first unit in each of data buffer regions, and the data of the first unit is transmitted from a host and written in a nonvolatile memory, or read from the nonvolatile memory and transmitted to the host. The second buffer controller is configured to independently transmit data of a second unit from the data buffer region corresponding to a bank prepared for transmission when data is written in the nonvolatile memory, and to independently transmit data of the second unit from a bank to be read to the data buffer region corresponding to the bank to be read when data is transmitted to the host.

Abstract: Disclosed is a novel method for group III polarity growth on a sapphire substrate. Specifically disclosed is a method for producing a laminate wherein a group III nitride single crystal layer is laminated on a sapphire substrate by an MOCVD method.

Abstract: A magnetic recording apparatus includes: a magnetic disk; a drive device; a magnetic disk control device; a buffer; and a flag management table. The buffer reads data of a specific block unit from a designated read range on the magnetic disk. The flag management table stores a pointer indicating the read location of the buffer for data of each of the block units and a management flag for the pointer. The magnetic disk control device sets the management flag of the pointer corresponding to a given block unit when the data of the given block unit is read to the buffer.

Abstract: According to one embodiment, a disk storage apparatus includes a write module, an operation module, and a controller. The write module is configured to write data, in units of blocks, in a designated write area of a disk. The operation module is configured to perform an exclusive OR operation on the blocks of data. The controller is configured to control the write module, causing the write module to write, in a designated block, recovery data that is a result of the exclusive OR operation on all data blocks written in the designated write area.

Abstract: A method for manufacturing an optical element includes a step wherein an aluminum nitride single crystal layer is formed on an aluminum nitride seed substrate having an aluminum nitride single crystal surface as the topmost surface. A laminated body for an optical element is manufactured by forming an optical element layer on the aluminum nitride single crystal layer, and the aluminum nitride seed substrate is removed from the laminated body. An optical element having, as a substrate, an aluminum nitride single crystal layer having a high ultraviolet transmittance and a low dislocation density is provided.

Abstract: Disclosed is a novel method wherein an aluminum nitride single crystal having good crystallinity is efficiently and easily manufactured. The method for produsing an aluminum nitride single crystal wherein nitrogen gas is circulated in the presence of a raw material gas generation source, which generates an aluminum gas or an aluminum oxide gas, and a carbon body, and then the aluminum nitride single crystal is grown under a heating condition; characterized in that, at least a part of the carbon body does not directly contact with the raw material gas generation source, at least a part of the raw material gas generation source does not directly contact with the carbon body, the raw material gas generation source and the carbon body are positioned to make a space in which a clearance between the raw material gas generation source, which does not contact with the carbon body, and the carbon body, which does not contact with the raw material gas generation source, is 0.

Abstract: Disclosed is a novel method for group III polarity growth on a sapphire substrate. Specifically disclosed is a method for producing a laminate wherein a group III nitride single crystal layer is laminated on a sapphire substrate by an MOCVD method.

Abstract: This invention provides a p-type group III nitride semiconductor, with good p-type properties, having a composition expressed by AlXGaYInZN in which each of X, Y and Z indicates a rational number satisfying a relationship of X+Y+Z=1.0, even if Al content is as high as 1.0>X?0.5. It is achieved that a proportion of a hole concentration at 30° C. to an acceptor impurity atom concentration is 0.001 or more in the p-type group III nitride semiconductor of the invention, by doping acceptor impurity atoms such as Mg in concentration of 5×1018 to 1×1020 cm?3 using the method, for example, MOCVD with attention not to incorporate an impurity atom other than the acceptor impurity atom or not to form dislocation in the crystal when producing the group III nitride semiconductor expressed by the above composition.

Abstract: A production method of a layered body having a single crystal layer including a group III nitride having a composition AlXGaYInZN (wherein, X, Y and Z are rational numbers respectively satisfying 0.9?X?1.0, 0.0?Y?0.1, 0.0?Z?0.1, and X+Y+Z=1.

Abstract: A magnetic recording apparatus includes: a magnetic disk; a drive device; a magnetic disk control device; a buffer; and a flag management table. The buffer reads data of a specific block unit from a designated read range on the magnetic disk. The flag management table stores a pointer indicating the read location of the buffer for data of each of the block units and a management flag for the pointer. The magnetic disk control device sets the management flag of the pointer corresponding to a given block unit when the data of the given block unit is read to the buffer.

Abstract: In a method of manufacturing an aluminum nitride single crystal film on a substrate by heating a sapphire substrate in the presence of carbon, nitrogen and carbon monoxide, an aluminum compound which differs from the raw material sapphire substrate and the formed aluminum nitride single crystal and can control the concentration of aluminum in the heating atmosphere, such as aluminum nitride or alumina, is made existent in a reaction system to promote a reduction nitriding reaction. An aluminum nitride single crystal multi-layer substrate having an aluminum nitride single crystal film on the surface of a sapphire substrate, wherein the aluminum nitride single crystal has improved crystallinity and a low density of defects, is provided.

Abstract: This invention provides a self supporting substrate which consists of a n-type conductive aluminum nitride semiconductor crystal and is useful for manufacturing the vertical conductive type AlN semiconductor device. The n-type conductive aluminum nitride semiconductor crystal, by which the self supporting substrate is made up, contains Si atom at a concentration of 1×1018 to 5×1020 cm?3 is substantially free of halogen atoms and substantially does not absorb the light having the energy of not more than 5.9 eV. The self supporting substrate can be obtained by a method comprising the steps of forming an AlN crystal layer on a single crystal substrate such as a sapphire by the HVPE method, preheating the obtained substrate having the AlN crystal layer to a temperature of 1,200° C. or more, forming a second layer consisting of the n-type conductive aluminum nitride semiconductor crystal is formed on the AlN crystal layer in high rate by the HVPE method and separating the second layer from the obtained laminate.

Abstract: According to one embodiment, a disk storage apparatus includes a write module, an operation module, and a controller. The write module is configured to write data, in units of blocks, in a designated write area of a disk. The operation module is configured to perform an exclusive OR operation on the blocks of data. The controller is configured to control the write module, causing the write module to write, in a designated block, recovery data that is a result of the exclusive OR operation on all data blocks written in the designated write area.

Abstract: According to one embodiment, a data storage device is provided, which has a cache controller that performs cache control, by using a buffer memory divided into segments, which are managed. The cache controller performs sequential hit judge on each segment, in accordance with the requested access range designated by a read or write command coming from a host system. The cache controller updates the hit upper-limit LBA set for each segment if the result of the hit judge is a mishit.

Abstract: This invention provides a p-type group III nitride semiconductor, with good p-type properties, having a composition expressed by AlxGayInzN in which each of X, Y and Z indicates a rational number satisfying a relationship of X+Y+Z=1.0, even if Al content is as high as 1.0>X?0.5. It is achieved that a proportion of a hole concentration at 30° C. to an acceptor impurity atom concentration is 0.001 or more in the p-type group III nitride semiconductor of the invention, by doping acceptor impurity atoms such as Mg in concentration of 5×1018 to 1×1020 cm?3 using the method, for example, MOCVD with attention not to incorporate an impurity atom other than the acceptor impurity atom or not to form dislocation in the crystal when producing the group III nitride semiconductor expressed by the above composition.