Abstract: A first object of the present invention is to provide a surface-modified inorganic nitride having excellent dispersibility. Furthermore, a second object of the present invention is to provide a composition, a thermally conductive material, and a device with a thermally conductive layer which contain the surface-modified inorganic nitride. The surface-modified inorganic nitride of the present invention includes an inorganic nitride, and a compound which is represented by General Formula (I) and is adsorbed onto a surface of the inorganic nitride. In General Formula (1), n represents an integer of 3 or greater. X represents an aromatic hydrocarbon ring group or an aromatic heterocyclic group. Y represents a single bond, —O—, —CO—, —CO—O—, —O—CO—, —S—, —CS—, —NRA—, —N?N—, or a divalent unsaturated hydrocarbon group. RA represents a hydrogen atom or an alkyl group. R1 and R2 each independently represent a substituent.

Abstract: An object of the present invention is to provide a surface-modified inorganic nitride having excellent dispersibility. Furthermore, another object of the present invention is to provide a composition, a thermally conductive material, and a device with a thermally conductive layer which contain the surface-modified inorganic nitride. The surface-modified inorganic nitride of the present invention includes an inorganic nitride, and a compound which is represented by General Formula (I) and is adsorbed onto a surface of the inorganic nitride.

Abstract: A light emitting element comprises a first n-side semiconductor layer, a first active layer having a first well layer containing indium, a first p-side semiconductor layer, a second n-side semiconductor layer in contact with the first p-side semiconductor layer, a second active layer having a second well layer containing indium, and a second p-side semiconductor, each formed of a nitride semiconductor. The second active layer has a first intermediate layer positioned closer to the first active layer than is the second well layer and containing indium. An indium composition ratio of the first well layer is less than an indium composition ratio of the second well layer. An indium composition ratio of the first intermediate layer is less than an indium composition ratio of the first well layer. A thickness of the first intermediate layer is less than a thickness of the second well layer.

Abstract: A method for manufacturing a light-emitting element, includes: introducing a gas comprising gallium, an ammonia gas, and a gas comprising a p-type impurity to a reactor and forming a first p-type nitride semiconductor layer on a first light-emitting layer in a state in which the reactor has been heated to a first temperature; introducing an ammonia gas at a first flow rate and a nitrogen gas to the reactor in a state in which the reactor is held at the first temperature; and subsequently introducing a gas comprising gallium, an ammonia gas at a second flow rate, and a gas comprising an n-type impurity to the reactor, and forming a second n-type nitride semiconductor layer on the first p-type nitride semiconductor layer. The first flow rate is less than the second flow rate.

Abstract: A method includes forming a first n-type nitride semiconductor layer; forming a first light-emitting layer on the first n-type nitride semiconductor layer; forming a first nitride semiconductor layer on the first light-emitting layer by introducing a gas comprising gallium and having a first flow rate; forming a first p-type nitride semiconductor layer on the first nitride semiconductor layer; forming an n-type intermediate layer on the first p-type nitride semiconductor layer; forming a second n-type nitride semiconductor layer on the n-type intermediate layer; forming a second light-emitting layer on the second n-type nitride semiconductor layer; forming a second nitride semiconductor layer on the second light-emitting layer by introducing a gas comprising gallium and having a second flow rate; and forming a second p-type nitride semiconductor layer on the second nitride semiconductor layer. The first flow rate is less than the second flow rate.

Abstract: A method of manufacturing a light emitting element includes: forming a first n-type semiconductor layer containing an n-type impurity; forming, on the first n-type semiconductor layer, a first superlattice layer, which is grown at a first growth temperature; forming, on the first superlattice layer, a first light emitting layer; forming, on the first light emitting layer, a first p-type semiconductor layer containing a p-type impurity; forming, on the first p-type semiconductor layer, a tunnel junction part; forming, on the tunnel junction part, a second n-type semiconductor layer containing an n-type impurity; forming, on the second n-type semiconductor layer, a second superlattice layer, which is grown at a second growth temperature lower than the first growth temperature; forming, on the second superlattice layer, a second light emitting layer; and forming, on the second light emitting layer, a second p-type semiconductor layer containing a p-type impurity.

Abstract: A method includes: introducing a gas including gallium, an ammonia gas, and a gas including a p-type impurity to a reactor and forming a first p-type nitride semiconductor layer on a first light-emitting layer in a state in which the reactor has been heated to a first temperature; lowering a temperature of the reactor from the first temperature to a second temperature; introducing an ammonia gas with a first flow rate to the reactor and increasing the temperature of the reactor from the second temperature to a third temperature; and introducing a gas including gallium, an ammonia gas with a second flow rate, and a gas including an n-type impurity to the reactor, and forming a second n-type nitride semiconductor layer on the first p-type nitride semiconductor layer in a state in which the reactor has been heated to the third temperature.

Abstract: A light-emitting element includes: a first n-type nitride semiconductor layer; a first light-emitting layer located on the first n-type nitride semiconductor layer; a p-type GaN layer located on the first light-emitting layer; an n-type GaN layer located on the p-type GaN layer and doped with an n-type impurity at an impurity concentration higher than that of the first n-type nitride semiconductor layer; a non-doped GaN layer located between the p-type GaN layer and the n-type GaN layer, a thickness of the non-doped GaN layer being not more than a width of a depletion layer formed by the n-type and p-type GaN layers; a second n-type nitride semiconductor layer located on the n-type GaN layer and doped with an n-type impurity; a second light-emitting layer located on the second n-type nitride semiconductor layer; and a p-type nitride semiconductor layer located on the second light-emitting layer and doped with a p-type impurity.

Abstract: A method includes forming a first n-type nitride semiconductor layer; forming a first light-emitting layer on the first n-type nitride semiconductor layer; forming a first nitride semiconductor layer on the first light-emitting layer by introducing a gas comprising gallium and having a first flow rate; forming a first p-type nitride semiconductor layer on the first nitride semiconductor layer; forming an n-type intermediate layer on the first p-type nitride semiconductor layer; forming a second n-type nitride semiconductor layer on the n-type intermediate layer; forming a second light-emitting layer on the second n-type nitride semiconductor layer; forming a second nitride semiconductor layer on the second light-emitting layer by introducing a gas comprising gallium and having a second flow rate; and forming a second p-type nitride semiconductor layer on the second nitride semiconductor layer. The first flow rate is less than the second flow rate.

Abstract: A method for manufacturing a light-emitting element comprises: forming a mask comprising a first film and a second film such that the mask covers a first active layer and a second nitride semiconductor layer, which comprises: forming the first film covering at least an upper surface of the second nitride semiconductor layer, and forming the second film covering the first film; while the first active layer and the second nitride semiconductor layer are covered with the mask, forming a third nitride semiconductor layer at an exposed portion of a first nitride semiconductor layer, wherein a temperature at which the third nitride semiconductor layer is formed is less than a melting point of the second film; and after the forming of the third nitride semiconductor layer, removing the mask, during which lift-off of the mask is performed by removing the first film, which also removes the second film.

Abstract: A method includes: introducing a gas including gallium, an ammonia gas, and a gas including a p-type impurity to a reactor and forming a first p-type nitride semiconductor layer on a first light-emitting layer in a state in which the reactor has been heated to a first temperature; lowering a temperature of the reactor from the first temperature to a second temperature; introducing an ammonia gas with a first flow rate to the reactor and increasing the temperature of the reactor from the second temperature to a third temperature; and introducing a gas including gallium, an ammonia gas with a second flow rate, and a gas including an n-type impurity to the reactor, and forming a second n-type nitride semiconductor layer on the first p-type nitride semiconductor layer in a state in which the reactor has been heated to the third temperature.

Abstract: A light-emitting element includes: a first n-type nitride semiconductor layer; a first light-emitting layer located on the first n-type nitride semiconductor layer; a p-type GaN layer located on the first light-emitting layer; an n-type GaN layer located on the p-type GaN layer and doped with an n-type impurity at an impurity concentration higher than that of the first n-type nitride semiconductor layer; a non-doped GaN layer located between the p-type GaN layer and the n-type GaN layer, a thickness of the non-doped GaN layer being not more than a width of a depletion layer formed by the n-type and p-type GaN layers; a second n-type nitride semiconductor layer located on the n-type GaN layer and doped with an n-type impurity; a second light-emitting layer located on the second n-type nitride semiconductor layer; and a p-type nitride semiconductor layer located on the second light-emitting layer and doped with a p-type impurity.

Abstract: A method for manufacturing a light-emitting element comprises: forming a mask comprising a first film and a second film such that the mask covers a first active layer and a second nitride semiconductor layer, which comprises: forming the first film covering at least an upper surface of the second nitride semiconductor layer, and forming the second film covering the first film; while the first active layer and the second nitride semiconductor layer are covered with the mask, forming a third nitride semiconductor layer at an exposed portion of a first nitride semiconductor layer, wherein a temperature at which the third nitride semiconductor layer is formed is less than a melting point of the second film; and after the forming of the third nitride semiconductor layer, removing the mask, during which lift-off of the mask is performed by removing the first film, which also removes the second film.

Abstract: A semiconductor light emitting device is provided which has improved light emission efficiency. The semiconductor light emitting device includes an active layer having a quantum well structure. The quantum well structure includes well and barrier layers that are alternately and repeatedly deposited on one another. The well layer is formed of a gallium nitride group semiconductor that contains In. The well layer has a profile of composition ratio of In that includes a first portion, and a second portion that is in contact with the first portion. The concentration of In in the first portion is substantially fixed or reduced along the thickness direction of the well layer from the negative side to the positive side of the piezoelectric field that is produced in the well layer. The concentration of In in the second portion is sharply reduced with respect to the first portion.

Abstract: There is provided a power control method for a fiber laser processing machine including: a fiber laser oscillator having a plurality of fiber laser modules each of which generates a laser beam; a laser processing head for emitting the laser beam generated from the fiber laser oscillator; and a condenser lens with a prescribed focal length provided between a workpiece and the laser processing head, for irradiating the workpiece with the laser beam having a spot diameter output from the laser processing head, wherein the number of the plurality of fiber laser modules oscillated is adjusted so as to achieve the spot diameter corresponding to the workpiece, and thereby, a beam quality from the laser processing head is adjusted.

Abstract: A railroad vehicle where an air conditioner can be installed in an upper part of a roof thereof includes a roof structure having an opening, and a low roof main body having a recessed part provided in the opening, and recessed in a cross section, the air conditioner being able to be placed on the recessed part, and an edge part of the low roof main body which is continuously formed from the low roof main body and joined to the roof structure. The low roof main body and the edge part of the low roof main body are made of plastic.

Abstract: A collision energy absorption column is provided on an end side of a railroad vehicle structure and extends from an end beam toward a roof structure. The collision energy absorption column includes a metal outer member having a transverse cross section of a channel shape, and an inner member made of reinforced plastic provided along an inner circumference of the outer member and extending in parallel with the outer member. The outer member is configured by joining two column halves extending along a column axis after arranging the two column halves are arranged in a direction perpendicular to the column axis of the outer member. The joined part of the column halves extends along the column axis. The outer member is coupled to the end beam and roof by a fastener. The inner member extends between the end beam and a part of the roof structure, excluding the fastening parts.

Abstract: A laser device includes an optical fiber laser unit including an amplification optical fiber, a plurality of pumping light sources outputting pumping lights for optically pumping the amplification optical fiber, and a controller controlling the pumping light sources. When an instruction value for supplying a predetermined driving electric current to each of the pumping light sources is input to the controller, the controller conducts a control of supplying a compensated electric current value as a driving electric current obtained by multiplying an initial electric current value corresponding to the instruction value by a compensation coefficient and supplying the compensated electric current value to each of the pumping light sources. The compensation coefficient is set to restrain a decrease in a power with time of a laser light output from the optical fiber laser unit.

Abstract: A railcar includes a heat-resistant floor, and the heat-resistant floor includes a floor panel, a heat absorbing layer provided under the floor panel and configured to absorb heat, and a supporting plate configured to support the heat absorbing layer from below. The supporting plate includes contacting portions each configured to contact the heat absorbing layer and separated portions each continuously formed from the contacting portion in a railcar width direction, separated downward from the heat absorbing layer, and extending in a railcar longitudinal direction.

Abstract: There is provided a power control method for a fiber laser processing machine including: a fiber laser oscillator having a plurality of fiber laser modules each of which generates a laser beam; a laser processing head for emitting the laser beam generated from the fiber laser oscillator; and a condenser lens with a prescribed focal length provided between a workpiece and the laser processing head, for irradiating the workpiece with the laser beam having a spot diameter output from the laser processing head, wherein the number of the plurality of fiber laser modules oscillated is adjusted so as to achieve the spot diameter corresponding to the workpiece, and thereby, a beam quality from the laser processing head is adjusted.