Abstract: A copper alloy plate containing in a center part of a plate thickness direction more than 2.0% (% by mass) and 32.5% or less of Zn; 0.1% or more and 0.9% or less of Sn; 0.05% or more and less than 1.0% of Ni; 0.001% or more and less than 0.1% of Fe, and 0.005% or more and 0.1% or less of P; and the balance Cu, including a surface layer part in which a surface Zn concentration in a surface is 60% or less of a center Zn concentration in the center part, having a depth from the surface to where Zn concentration is 90% of the center Zn concentration; and in the surface layer, the Zn concentration increases from the surface toward the center part in the plate thickness direction at a concentration gradient of 10% by mass/?m or more and 1000% by mass/?m or less.

Abstract: Providing a copper alloy plate, in which center Mg concentration at a center part in a plate thickness direction 0.1 mass % or more and less than 0.3 mass %, center P concentration is 0.001 mass % or more and 0.2 mass % or less, and the balance is composed of Cu and inevitable impurities; in which surface Mg concentration at a surface is 70% or less of the center Mg concentration; in which a surface layer part defined by a prescribed thickness from the surface has a concentration gradient of Mg of 0.05 mass %/?m or more and 5 mass %/?m or less increasing from surface toward center part of the plate thickness direction; and in which restraint of color change of the surface and increase of electrical contact resistance, and adhesiveness of a plating film are excellent due to maximum Mg concentration in the surface layer part is 90% of the center Mg concentration.

Abstract: A portable drone port that is portable and disposed on a landing surface for a drone includes a covering section configured to cover the landing surface and provided with markers of different sizes. The covering section includes a restraining section configured to restrain, on the covering section, the drone that lands on the covering section. The restraining section is hook-and-loop fasteners including a hook-and-loop fastener on one side disposed on the covering section and a hook-and-loop fastener on the other side disposed on the drone and configured to join to the hook-and-loop fastener on the one side.

Abstract: To provide an unmanned aerial vehicle that eliminates or minimizes the laboriousness involved in optimal pitch adjustment of propellers while eliminating or minimizing complexity and instability in airframe structure and/or flight programs. This object is solved by an unmanned aerial vehicle that is provided with a plurality of rotors and that includes: a center frame that is a central portion of an airframe of the unmanned aerial vehicle; and a plurality of arms extending radially from the center frame in plan view. A plurality of motors that are driving sources of the respective rotors are provided in the center frame. The plurality of rotors are supported by the respective arms. Each arm of the arms has a hollow cylindrical structure. A motive power transmission member configured to transmit a driving force of each motor of the motors to the each rotor is provided in the each arm.

Abstract: To provide an unmanned aerial vehicle that eliminates or minimizes the laboriousness involved in optimal pitch adjustment of propellers while eliminating or minimizing complexity and instability in airframe structure and/or flight programs. This object is solved by an unmanned aerial vehicle that is provided with a plurality of rotors and that includes: a center frame that is a central portion of an airframe of the unmanned aerial vehicle; and a plurality of arms extending radially from the center frame in plan view. A plurality of motors that are driving sources of the respective rotors are provided in the center frame. The plurality of rotors are supported by the respective arms. Each arm of the arms has a hollow cylindrical structure. A motive power transmission member configured to transmit a driving force of each motor of the motors to the each rotor is provided in the each arm.

Abstract: A memory unit having a plurality of heads performing at least one of recording or reproducing operations on a storage medium is disclosed. The memory unit includes a first converter circuit for receiving head-selection signals as first parallel data and converting the head-selection signals to first serial data to be transmitted, and a second converter circuit for receiving the first serial data from the first converter circuit and converting the first serial data to second parallel data to be transmitted. The memory unit further includes a head control circuit for receiving the second parallel data from the second converter circuit and selectively driving the heads on the basis of the second parallel data.

Abstract: A memory unit having a plurality of heads performing at least one of recording or reproducing operations on a storage medium is disclosed. The memory unit includes a first converter circuit for receiving head-selection signals as first parallel data and converting the head-selection signals to first serial data to be transmitted, and a second converter circuit for receiving the first serial data from the first converter circuit and converting the first serial data to second parallel data to be transmitted. The memory unit further includes a head control circuit for receiving the second parallel data from the second converter circuit and selectively driving the heads on the basis of the second parallel data.

Abstract: A method and disk apparatus, for writing data disk apparatus, that reduces the adverse influence of noise caused by data head writing on a read signal of a servo head even though the data head and the servo head are collaterally paired with no disks there between. A magnetic disk apparatus comprises a plurality of magnetic disks that are stacked at predetermined intervals; a servo head for reading servo signals recorded on a servo surface of one of the magnetic disks; a plurality of data heads, one of which is provided for each data surface of the magnetic disks with a first data head being collaterally positioned with the servo head, with no intervening magnetic disk, and second data heads being positioned at other than the collateral position; and an actuator for supporting the servo head and the data heads and for positioning the servo head and the data heads by moving them radially relative to the magnetic disks.