Abstract: A heat exchanger includes: a heat exchange core portion; and a tank portion connected to the heat exchange core portion. The heat exchange core portion has a connection plate that surrounds a part of the tank portion from an outer peripheral side. The connection plate has slit-shaped openings arranged along an edge of the connection plate in a first direction. A part of the connection plate between each of the openings and the edge is deformable into a concave shape toward the tank portion. A part of the openings has a widened portion at both ends in the first direction. A width dimension of the widened portion in a second direction from the opening to the edge is larger than that of the other portion of the opening.

Abstract: A heat exchanger includes a plate member, a fixation member, and a brazing material pathway. The plate member has a first side coated with a brazing material, and a second side which is an opposite side of the first side and is not coated with the brazing material. The fixation member is disposed on the second side and configured to fix a position of a pipe. The brazing material pathway extends from the first side to the second side. The brazing material coated on the plate member spreads into the brazing material pathway. The pipe is inserted into an insertion hole formed in the plate member. An entire outer circumference of the pipe is swaged and engaged with an inner side of the insertion hole. The brazing material pathway is formed on at least the outer circumference of the pipe or the inner side of the insertion hole.

Abstract: The ultraviolet light-emitting device includes a base, a nitride semiconductor ultraviolet light-emitting element flip-chip mounted on the base, and a lens for sealing a nitride semiconductor ultraviolet light-emitting element to focus or diffuse light emitted from the nitride semiconductor ultraviolet light-emitting device. The lens is composed of an amorphous fluororesin in which a structural unit of a polymer or copolymer has a fluorine-containing aliphatic cyclic structure and a terminal functional group is a perfluoroalkyl group, and a density of the amorphous fluororesin is higher than 2.11 g/cm3.

Abstract: An optical amplification system includes: three or more nodes; a multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of the connection between the nodes; an amplification light input unit configured to input amplification light to a core of the plurality of cores of the multi-core fiber; an amplification unit configured to amplify communication light transmitted through at least one core of the plurality of cores of the multi-core fiber using the amplification light, the amplification unit being provided in the nodes or between the nodes; and an amplification light coupling unit configured to couple the amplification light input by the amplification light input unit to the amplification unit.

Abstract: A template includes a sapphire substrate with a (0001) plane or a plane inclined by a predetermined angle with respect to the (0001) plane as a main surface, and an AlN layer composed of AlN crystals having an epitaxial crystal orientation relationship with the main surface directly formed on the main surface of the sapphire substrate. In the template, an average particle diameter of the AlN crystals of the AlN layer at a thickness of 20 nm from the main surface is 100 nm or less.

Abstract: An automatic bias control circuit for an optical modulator using nested MZIs includes: a parent MZI control bias voltage generator that generates a parent MZI control bias voltage; a photodetector that converts tapped output light from the optical modulator into an electrical signal; a low-frequency cut-off circuit that suppresses modulation components that are slower than a first frequency, included in the electrical signal; and a control unit that controls the parent MZI control bias voltage generator on the basis of an electrical signal in which the slower modulation components have been suppressed. The control unit controls the parent MZI control bias voltage generator so as to minimize the effective value or the peak value of the electrical signal in which the slower modulation components have been suppressed.

Abstract: A transmission device includes a frame processing unit, a redundant channel processing unit, a transmission and reception unit, and a channel selection unit. The frame processing unit generates division frames, adds error detection signals to the division frames, and outputs the division frames to which the error detection signals are added to a plurality of data channels. The redundant channel processing unit generates, from the division frames, one or more redundant frames including restoration information that enables restoration of the division frames, and outputs the generated redundant frames to a data channel. The transmission and reception unit outputs the division frames and the redundant frames to a transmission line. The channel selection unit allocates the division frames and the redundant frames to allocable transmission and reception units.

Abstract: Glass for a vehicle includes a glass plate; a test-region A demarcated in the glass plate, the test-region A being specified in JIS R3212; a shielding layer provided more outwardly than the test-region A in a plan view; an information transmission/reception region demarcated within an opening portion provided in the shielding layer, and through which a device mounted in the vehicle transmits/receives information; and an infrared reflective layer positioned peripheral to the information transmission/reception region in a plan view, the infrared reflective layer having a portion that overlaps with the shielding layer in a plan view, wherein a solar direct transmittance of the test-region A is 60% or less and a solar direct reflectance of a region in which the infrared reflective layer is provided peripheral to the information transmission/reception region is greater than a solar direct reflectance of the test-region A by at least 5%.

Abstract: To improve a wall plug efficiency in a nitride semiconductor light-emitting element for extracting ultraviolet light emitted from an active layer toward an n-type nitride semiconductor layer side to outside of the element.

Abstract: There is provided an optical transmission system in which a plurality of optical transmission and reception apparatuses perform 1-to-N transmission and reception of optical signals (N is an integer equal to or greater than 1), the optical transmission system being configured to select a communication condition that includes at least a modulation scheme or a baud rate and is a communication condition when each of the optical transmission and reception apparatuses performs transmission and reception in accordance with a transmission line condition that is between any one first optical transmission and reception apparatus and each of second optical transmission and reception apparatuses, which are N grounds, other than the first optical transmission and reception apparatus.

Abstract: A state estimating device includes a pre-processing unit and an estimating unit. The pre-processing unit acquires data representing at one or more of a phase of a signal transmitted from a transmission unit of a transmission device and received at a reception unit of another transmission device via a transmission path, a reception strength, a reception quality, a voltage after conversion into an electric signal, and a signal processing parameter used in reception processing, and processes the acquired data into feature data to be used for state estimation. The estimating unit estimates a state of the transmission path, an abnormal state of the transmission unit, or an abnormal state of the reception unit, on the basis of the feature data.

Abstract: An axle structure is provided with an axle housing for internally passing an axle shaft having wheels connected to both left and right ends thereof, and a drive motor unit. The axle housing includes a large diameter housing center portion having a recessed portion which is recessed from an opening portion on a front surface side toward a rear surface side, and small diameter hollow shaft portions connected as a left and right pair to both sides of the housing center portion. The drive motor unit is fitted into the recessed portion and is bolted to the axle housing by means of tightening bolts.

Abstract: A template includes a sapphire substrate with a (0001) plane or a plane inclined by a predetermined angle with respect to the (0001) plane as a main surface, and an AlN layer composed of AlN crystals having an epitaxial crystal orientation relationship with the main surface directly formed on the main surface of the sapphire substrate. In the template, an average particle diameter of the AlN crystals of the AlN layer at a thickness of 20 nm from the main surface is 100 nm or less.

Abstract: The nitride semiconductor light-emitting element comprises a light-emitting element structure portion having a plurality of nitride semiconductor layers including at least an n-type layer, an active layer and a p-type layer. The active layer has a quantum well structure comprising at least one well layer composed of a GaN-based semiconductor. In the well layer, the shortest distance between a first surface on the n-type layer side and a second surface on the p-type layer side varies in an orthogonal plane to the layering direction of the nitride semiconductor layers, and the peak emission wavelength of light emitted from the light-emitting element structure portion is shorter than 354 nm.

Abstract: A control unit of a bias control circuit performs a loop process that fixes a second bias voltage and iterates a process of recording a pair of a first candidate bias voltage and a second candidate bias voltage that are a first bias voltage when optical power of a multi-level QAM signal output by an optical modulator is controlled so that the optical power converges to a value in the vicinity of the maximum value or the minimum value before and after a third bias voltage is increased or decreased by a half-wave voltage while changing the second bias voltage within a predetermined range. The control unit calculates the difference between the first candidate bias voltage and the second candidate bias voltage for each of a plurality of recorded pairs and determines a value between first candidate bias voltage and the second candidate bias voltage of a pair selected on the basis of the calculated difference as the value of the first bias voltage.

Abstract: Provided is an ultraviolet light emitting device having high quality and high reliability that prevents deterioration in electrical characteristics caused by a photochemical reaction of a non-bonding amorphous fluororesin, decomposition or the like of the amorphous fluororesin, and peeling off of the amorphous fluororesin. A nitride semiconductor ultraviolet light emitting device 1 includes a base 30, a nitride semiconductor ultraviolet light emitting element flip-chip mounted on the base 30, and an amorphous fluororesin 40 that is in direct contact with the nitride semiconductor ultraviolet light emitting element for covering. The nitride semiconductor ultraviolet light emitting element includes a sapphire substrate 11, a plurality of AlGaN-based semiconductor layers 12 laminated on the main surface of the sapphire substrate 11, an n-electrode 13, and a p-electrode 14.

Abstract: The ultraviolet light-emitting device includes a base, a nitride semiconductor ultraviolet light-emitting element flip-chip mounted on the base, and a lens for sealing a nitride semiconductor ultraviolet light-emitting element to focus or diffuse light emitted from the nitride semiconductor ultraviolet light-emitting device. The lens is composed of an amorphous fluororesin in which a structural unit of a polymer or copolymer has a fluorine-containing aliphatic cyclic structure and a terminal functional group is a perfluoroalkyl group, and a density of the amorphous fluororesin is higher than 2.11 g/cm3.

Abstract: An optical receiver includes: a first calculation unit that obtains a log likelihood ratio for each M-dimension (M is a natural number), based on a received signal; and a second calculation unit that obtains a log likelihood ratio of an N dimensional symbol (N is a natural number), based on the log likelihood ratio for each M-dimension.

Abstract: A transmission quality estimation system includes, three or more nodes and a transmission quality estimation device configured to estimate, transmission quality. A multi-core fiber having a plurality of cores, the multi-core fiber being used in at least a partial segment of a connection between the nodes. A node of the nodes includes a core connection unit configured to drop, add or relay light transmitted from, to or to each of to the plurality of cores of the multi-core fiber. The transmission quality estimation device includes an estimation unit configured to estimate transmission quality between the nodes on the basis of a transmission quality measurement light dropped by the core connection unit.

Abstract: A light-emitting device 1 comprises a base 30, a nitride semiconductor light-emitting element 10 flip-chip mounted on the base 30, and an amorphous fluororesin sealing the nitride semiconductor light-emitting element 10. The light-emitting device 1 comprises a deformation-prevention layer 60 for preventing a shape change of an amorphous fluororesin by heat treatment after shipment of the light-emitting device 1, and the deformation-prevention layer 60 is formed of a layer in which a thermosetting resin or an ultraviolet curing resin is cured, and the cured layer directly covers the surface of the amorphous fluororesin.