Abstract: A method for producing an electrically conductive paste, including a step of manufacturing paste A by exerting a cavitation effect in mixed liquid A containing multi-walled carbon nanotubes and a solvent, a step of manufacturing paste B from mixed liquid B containing carbon black particles, graphitized carbon nanofibers and a solvent, and a step of mixing paste A and paste B.

Abstract: A method for producing an electrically conductive paste, including a step of manufacturing paste A by exerting a cavitation effect in mixed liquid A containing multi-walled carbon nanotubes and a solvent, a step of manufacturing paste B from mixed liquid B containing carbon black particles, graphitized carbon nanofibers and a solvent, and a step of mixing paste A and paste B.

Abstract: Carbon fibers containing at least one element (I) selected from the group consisting of Fe, Co and Ni, at least one element (II) selected from the group consisting of Sc, Ti, V, Cr, Mn, Cu, Y, Zr, Nb, Tc, Ru, Rh, Pd, Ag, a lanthanide, Hf, Ta, Re, Os, Ir, Pt and Au, and at least one element (III) selected from the group of W and Mo, wherein the element (II) and the element (III) each is 1 to 100 mol % relative to the mols of element (I).

Abstract: A catalyst for producing a carbon nanofiber is obtained by dissolving or dispersing [I] a compound containing Fe element; [II] a compound containing Co element; [III] a compound containing at least one element selected from the group consisting of Ti, V, Cr, and Mn; and [IV] a compound containing at least one element selected from the group consisting of W and Mo in a solvent to obtain a solution or the fluid dispersion, and then impregnating a particulate carrier with the solution or the fluid dispersion. A carbon nanofiber is obtained by bringing a carbon element-containing compound into contact with the catalyst in a vapor phase at a temperature of 300 degrees C. to 500 degrees C.

Abstract: A method for producing a carbon fiber, comprising a step of dissolving or dispersing [I] a compound containing Co element; [II] a compound containing at least one element selected from the group consisting of Ti, V, Cr, and Mn; and [III] a compound containing at least one element selected from the group consisting of W and Mo in a solvent to obtain a solution or a fluid dispersion, a step of impregnating a particulate carrier with the solution or the fluid dispersion to prepare a catalyst, and a step of bringing a carbon source into contact with the catalyst in a vapor phase.

Abstract: A catalyst for production of a carbon fiber is obtained by dissolving or dispersing [I] a compound containing Fe element; [II] a compound containing Co element; [III] a compound containing at least one element selected from the group consisting of Ti, V, Cr, and Mn; and [IV] a compound containing at least one element selected from the group consisting of W and Mo in a solvent to obtain a solution or a fluid dispersion, and then by impregnating a particulate carrier with the solution or the fluid dispersion. By means of a step of bringing a carbon source into contact with the catalyst in a vapor phase, the carbon fiber is obtained which is tubular and in which a graphite layer is approximately parallel with the carbon fiber axis, and a shell is in a multi-walled structure.

Abstract: A catalyst for producing a carbon nanofiber is obtained by dissolving or dispersing [I] a compound containing Fe element; [II] a compound containing Co element; [III] a compound containing at least one element selected from the group consisting of Ti, V, Cr, and Mn; and [IV] a compound containing at least one element selected from the group consisting of W and Mo in a solvent to obtain a solution or the fluid dispersion, and then impregnating a particulate carrier with the solution or the fluid dispersion. A carbon nanofiber is obtained by bringing a carbon element-containing compound into contact with the catalyst in a vapor phase at a temperature of 300 degrees C. to 500 degrees C.

Abstract: A method for producing a carbon fiber, comprising a step of dissolving or dispersing [I] a compound containing Co element; [II] a compound containing at least one element selected from the group consisting of Ti, V, Cr, and Mn; and [III] a compound containing at least one element selected from the group consisting of W and Mo in a solvent to obtain a solution or a fluid dispersion, a step of impregnating a particulate carrier with the solution or the fluid dispersion to prepare a catalyst, and a step of bringing a carbon source into contact with the catalyst in a vapor phase.

Abstract: Carbon fibers containing at least one element (I) selected from the group consisting of Fe, Co and Ni, at least one element (II) selected from the group consisting of Sc, Ti, V, Cr, Mn, Cu, Y, Zr, Nb, Tc, Ru, Rh, Pd, Ag, a lanthanide, Hf, Ta, Re, Os, Ir, Pt and Au, and at least one element (III) selected from the group of W and Mo, wherein the element (II) and the element (III) each is 1 to 100 mol % relative to the mols of element (I).

Abstract: The present invention provides an epitaxial wafer which is obtained by sequentially forming, on an n-type GaAs substrate, a first n-type GaAlAs layer; a second n-type GaAlAs layer; an n-type GaAlAs cladding layer; a p-type GaAlAs active layer which has an emission wavelength of 850-900 nm; and a p-type GaAlAs cladding layer, through liquid phase epitaxy, and, subsequently, removing the n-type GaAs substrate. In the epitaxial wafer, the p-type GaAlAs cladding layer has a thickness of 5-30 &mgr;m; the p-type GaAlAs cladding layer has an oxygen concentration of 3×1016 atoms/cm3 or less; the p-type GaAlAs cladding layer has a carrier concentration of 1×1017 cm−3 to 1×1018 cm−3; the p-type GaAlAs active layer has a thickness of 0.05-0.