Abstract: A gain flattening filter includes a first optical fiber that has a core, a first cladding, and a second cladding and that has a uniform composition in a length direction; and a pair of second optical fibers fused to both ends of the first optical fiber. The first optical fiber has a first section in which a slanted refractive index grating is formed and a pair of second sections connecting both ends of the first section to the pair of second optical fibers. The first cladding contains a photosensitive material whose refractive index increases upon irradiation with light having a specific wavelength. In the core, a tensile stress remains in the first section. An average MFD of the second sections is larger than an average MFD of the second optical fibers and smaller than an average MFD of the first section.

Abstract: A metal porous body includes: a metal framework; and a separation wall formed in one piece with the metal framework, the separation wall being composed of the same material as a material of the metal framework. A plurality of cells each having a polyhedral shape exist inside the metal porous body. A side of the polyhedral shape is constituted of the metal framework. A location in which an opening of a cell of the plurality of cells is closed by the separation wall exists inside the metal porous body, the opening being defined by a side of a polyhedral shape of the cell.

Abstract: A vehicle network system is provided with a plurality of star networks, a plurality of devices mounted on a vehicle are connected in a star shape through respective branch lines in each of the star networks, and a trunk line for connecting the plurality of star networks, the branch lines are communication lines for optical communications, and the trunk line is a communication line for electric communication.

Abstract: An optical fiber comprising a core region 100 doped with Cl which raises the refractive index; and a cladding region 200, provided at the outer periphery of the core region 100, having a cladding layer 201 doped with F which lowers the refractive index is formed. The cladding region 201 to become the outermost cladding layer is configured such that the doping amount of F successively decreases within an outer peripheral part 205 including the outer periphery thereof to a predetermined doping amount which is the minimum doping amount of F within the cladding layer 201. Therefore, the stress within the optical fiber is dispersed into the outer peripheral part 205 having an enhanced viscosity, whereby the stress concentration into the core is suppressed. Since the favorable tension range at the time of drawing the optical fiber becomes wider at this time, tension control is facilitated.

Abstract: An optical fiber (1) which does not readily suffer influences of side pressures and can realize superior transmission characteristics, having a glass part (2, 3) having a core (2) and at least one cladding (3) and at least one covering layer (4a, 4b) formed around the glass part (2, 3), characterized in that the Young's modulus at 23° C. of the covering layer (4) without the glass part (2, 3) is not greater than 400 MPa. The Young's modulus measurement of the covering layer (4) is obtained by removing the glass part (2, 3) from the optical fiber (1) and putting the covering layer (4) to a tensile test.

Abstract: A battery electrode substrate which is constituted of a porous metallic body structure having communicating pores at a porosity of at least 90% and an Fe/Ni multilayer structure wherein the skeletal portion of the porous metallic body is composed mainly of Fe and has an Ni covering layer on the surface thereof while pores communicating with the inside and outside of Fe skeletal portion exist in the Fe skeletal portion and the inside of the pores is covered with Ni. The electrode substrate is produced by applying an iron oxide powder of at most 20 .mu.m in an average particle size on a porous resin core body; heat treating the core to remove an organic resin component while simultaneously sintering Fe to obtain a porous Fe body; and then covering the Fe skeletal portion with Ni by electroplating. In this process, the iron oxide can be used in combination with carbon powder. Further, a nickel porous sintered body can also be produced using nickel oxide in place of iron oxide.

Abstract: A method of preparing a compound semiconductor crystal in a crucible involves first forming a boron or boron compound containing layer on an inner surface of the crucible and heat treating the same to form a B.sub.2 O.sub.3 containing layer. The resulting preheated crucible is then employed for preparing the compound semiconductor crystal. By pretreating the crucible in this manner, it is possible to previously form a homogenous B.sub.2 O.sub.3 film on the crucible interior surface while preventing incomplete and heterogeneous coating of the B.sub.2 O.sub.3 film. Consequently, it is possible to prevent a raw material melt from wetting the crucible interior surface and thus to suppress polycrystallization, thereby preparing a compound semiconductor single crystal with an excellent yield.

Abstract: A chip collector is proposed which can collect chips efficiently and which is easy to maintain and allows replacement of throwaway inserts without removing the cutting tool from a spindle of a machine tool. The cylindrical casing is divided into two casing halves, one of which is pivotable from the other around a hinge. The chip collector is provided with a sub-chamber connected to a chip suction port and a discharge duct connected to the sub-chamber. Also, a face milling cutter used in combination with the chip collector is proposed.

Abstract: A brake system wherein an auxiliary power based on a manual force is electronically controlled to control the braking force so as to obtain braking effects corresponding to a manual control input. The braking force is controlled so that a vehicle deceleration corresponding to the control input can be obtained when the control input is equal to or greater than a comparatively small predetermined control input value Lo. When the control input is smaller than Lo, the braking force is controlled so that the vehicle acceleration will not exceed a value corresponding to the control input.

Abstract: A method for preparing single-crystal ZnSe comprising the steps of:working polycrystalline ZnSe into a rod-shaped starting material;placing the starting material in a reaction vessel;filling the atmosphere of the reaction vessel with an inert gas, nitrogen, H.sub.2 Se gas, or a mixture thereof at from about 0.1 to about 100 Torr; andconverting the polycrystalline ZnSe starting material to single-crystal ZnSe, while maintaining a solid phase, by moving the reaction vessel at a rate of from about 0.05 to about 5 mm/day through a temperature profile consisting of a cool zone AB having a temperature T.sub.1 in the range of from about room temperature to about 100.degree. C., a temperature increasing zone BC having a temperature gradient of from about 50.degree. to about 200.degree. C./cm, a hot zone CD having a temperature T.sub.2 in the range of from about 700.degree. to about 900.degree. C., a temperature decreasing zone DE having a temperature gradient of from about -200.degree. to about -50.degree. C.