Abstract: In a steel sheet pile according to the present invention, a carbon equivalent CEN is 0.260 to 0.500, a structure includes a ferrite, a pearlite, a Widmanstätten ferrite, and a precipitate, the precipitate is one or both of Nb carbonitride and V carbonitride, a total number density of the precipitate is 0.10 to 0.30 pieces/?m2, a total area ratio of the ferrite and the pearlite is 70% or more, an area ratio of the Widmanstätten ferrite is 1% or more, an average grain size of the ferrite and the pearlite is 10 to 80 ?m, and a yield strength is 460 MPa or more.

Abstract: This H-beam steel contains, in mass %, C, Si, Mn, Al, Ti, N, O, Nb, and B. The H-beam steel has composition in which the amount of Nb and the amount of B satisfy, in mass %, 0.070?Nb+125B?0.155, and has a metal structure in which, in a microstructure, an area fraction of bainite is not less than 70%, a total of an area fraction of pearlite and an area fraction of cementite is not more than 15%, and the remainder is at least one of ferrite and island martensite. The effective crystalline-grain size of the bainite is not more than 40 ?m, and the thickness of a flange falls in a range of 12 to 40 mm.

Abstract: An H-section steel has a predetermined chemical composition, an Nb content and a B content satisfy Nb+125×B?0.075%, a thickness of a flange is 12 mm to 40 mm, and in a thickness center portion and ¼ flange width portion of the flange, a metallographic structure of a cross-section perpendicular to a rolling direction contains pearlite having a distribution density of 3.2×10?3 units/?m2 or lower and the remainder is formed of ferrite and bainite.

Abstract: In a steel sheet pile according to the present invention, a carbon equivalent CEN is 0.260 to 0.500, a structure includes a ferrite, a pearlite, a Widmanstätten ferrite, and a precipitate, the precipitate is one or both of Nb carbonitride and V carbonitride, a total number density of the precipitate is 0.10 to 0.30 pieces/?m2, a total area ratio of the ferrite and the pearlite is 70% or more, an area ratio of the Widmanstätten ferrite is 1% or more, an average grain size of the ferrite and the pearlite is 10 to 80 ?m, and a yield strength is 460 MPa or more.

Abstract: This H-beam steel contains, in mass %, C, Si, Mn, Al, Ti, N, O, Nb, and B. The H-beam steel has composition in which the amount of Nb and the amount of B satisfy, in mass %, 0.070?Nb+125B?0.155, and has a metal structure in which, in a microstructure, an area fraction of bainite is not less than 70%, a total of an area fraction of pearlite and an area fraction of cementite is not more than 15%, and the remainder is at least one of ferrite and island martensite. The effective crystalline-grain size of the bainite is not more than 40 ?m, and the thickness of a flange falls in a range of 12 to 40 mm.

Abstract: A rail manufacturing method is provided, in which a billet is hot-rolled into a rail form and the rail is cooled to ambient temperature. The foot part of the rail can be mechanically restrained to improve the straightness of the rail during at least the period of cooling where the surface temperature is between 800° C. and 400° C. In the subsequent cooling process, at least while the surface temperature of the foot of the rail is between 400° C. and 250° C., the rail is kept in an upright state, and cooled naturally without using insulation or accelerated cooling.

Abstract: A rail manufacturing method is provided, in which a billet is hot-rolled into a rail form and the rail is cooled to ambient temperature. The foot part of the rail can be mechanically restrained to improve the straightness of the rail during at least the period of cooling where the surface temperature is between 800° C. and 400° C. In the subsequent cooling process, at least while the surface temperature of the foot of the rail is between 400° C. and 250° C., the rail is kept in an upright state, and cooled naturally without using insulation or accelerated cooling.

Abstract: A stabilized optical pulse generator using RHML-FRL is provided. The stabilized optical pulse generator comprises an optical fiber ring composed of optical fibers, an optical amplifier and a modulator for optical modulation, an electric signal generator generating high frequency signals and an optical pulse stabilizer. The device generates an optical pulse train of repeating frequency of fm, when applying electric signals of frequency of fm to the modulator. Wherein, for a resonance frequency of the optical fibers of fc, the modulating frequency applying to the modulator is detuned from the electric signal of the frequency of fm by frequency of the resonance frequency fc divided by integer of p. Optical pulse trains of repeating frequency of p times of fm+fc/p or fm?fc/p are generated.

Abstract: The present invention provides a method and equipment for producing a rail, the method and equipment being capable of lowering a bend at an end of a rail effectively and the truncation amount thereof. The present invention is a method for producing a rail, characterized by: cooling a hot-rolled mother rail to an ordinary temperature substantially while the length thereof after the hot rolling is maintained; and thereafter cutting the mother rail simultaneously in a predetermined length with at least three cold-sawing machines. Further, the present invention is equipment for producing a rail, characterized by equipped with: a transfer bed capable of moving a mother rail cooled to an ordinary temperature substantially while the length thereof after hot rolling is maintained in the rolling direction and/or in the direction perpendicular to the rolling direction; and at least three cold-sawing machines disposed in parallel with each other on said transfer bed.

Abstract: The present invention provides a method and equipment for producing a rail, the method and equipment being capable of lowering a bend at an end of a rail effectively and the truncation amount thereof. The present invention is a method for producing a rail, characterized by: cooling a hot-rolled mother rail to an ordinary temperature substantially while the length thereof after the hot rolling is maintained; and thereafter cutting the mother rail simultaneously in a predetermined length with at least three cold-sawing machines. Further, the present invention is equipment for producing a rail, characterized by equipped with: a transfer bed capable of moving a mother rail cooled to an ordinary temperature substantially while the length thereof after hot rolling is maintained in the rolling direction and/or in the direction perpendicular to the rolling direction; and at least three cold-sawing machines disposed in parallel with each other on said transfer bed.

Abstract: A stabilized optical pulse generator using RHML-FRL is provided. The stabilized optical pulse generator comprises an optical fiber ring composed of optical fibers, an optical amplifier and a modulator for optical modulation, an electric signal generator generating high frequency signals and an optical pulse stabilizer. The device generates an optical pulse train of repeating frequency of fm, when applying electric signals of frequency of fm to the modulator. Wherein, for a resonance frequency of the optical fibers of fc, the modulating frequency applying to the modulator is detuned from the electric signal of the frequency of fm by frequency of the resonance frequency fc divided by integer of p. Optical pulse trains of repeating frequency of p times of fm+fc/p or fm−fc/p are generated.

Abstract: A self-tuning mode locked semi-conductor laser automatically adjusts itself to produce short (less than 200 ps and preferably less than 50 ps) stable optical pulses. Tuning is achieved by means of a feedback loop which includes a spectrum analyzer (18) which receives a small amount of the optical output of the laser and monitors the spectral wavelength, spectral width or spectral shape of the output. A controller (19) is connected to said analyzer and produces a control signal based on said spectral information. The control signal causes adjustment of one or more parameters influencing operation of said laser, such as frequency or power of an RF drive signal, level of dc bias, cavity length, for example, in order to produce said short stable pulses.

Abstract: A photo-functional device has a semiconductor substrate, a light emitting section laminated on one surface of the semiconductor substrate and formed into a semiconductor laminate, a light receiving section laminated on the one surface of the semiconductor substrate, formed into a semiconductor laminate and electrically connected in series to the light emitting section, and a coupling rate conversion section disposed between the light emitting section and the light receiving section for converting a coupling rate of light coupled from the light emitting section to the light receiving section.

Abstract: A semiconductor light-emitting device includes a pair of clad layers and an active layer sandwiched thereby which together are disposed between a substrate and a cap layer so as to form a monolithic array of double-heterojunction regions each including therein a plurality of light-emitting portions of the active layer for emitting light from the end face thereof so that the light-emitting portions are arrayed in a row and electrically separated from each other. The substrate is formed at one side thereof with a concave and convex configuration following a stripe pattern so that the clad layers, active layers and the cap layers are each arranged in the form of a corrugated configuration following the concave and convex configuration of the substrate.

Abstract: A semiconductor light emitting device comprises a semiconductor substrate of a first conductivity type; an electric current blocking layer formed on one main face of the substrate and including a semiconductor of a second conductivity type opposite to the first conductivity type and having an opening reaching the main face; a first semiconductor layer of the first conductivity type formed on the electric current blocking layer and a portion of the main face on which the opening is disposed; a second semiconductor layer stacked on the first semiconductor layer and forming a hetero-junction together with the first semiconductor layer; a semiconductor layer for electrode of the second conductivity type formed on the second semiconductor layer and having a window reaching the second conductor layer in a position corresponding to the opening; a first electrode metallic layer formed on the electrode semiconductor layer except for the window; and a second electrode metallic layer formed on the other main face of the

Abstract: A semiconductor light emitting device, such as a light emitting diode or laser, includes a substrate which is provided with a hole and a pn junction extending adjacent to and in parallel with the side wall of the hole. Thus, the side wall of the hole extends in a direction perpendicular to a main surface of the substrate. A pair of electrodes is provided such that current flows across the pn junction so that light emitted in a vertical direction which is perpendicular to the main surface of the substrate. The hole may be either a through hole or a bore hole. With the additional provision of a pair of resonators, there is provided a semiconductor laser.