A rare earth doped optical fiber consisting of a first core doped with a rare earth element and having a relative index difference ranging from about 0.76% to about 1.5%, a second core surrounding the first core and having a relative index difference of about 1.8% or more, and a clad surrounding the second core. The refractive index of the first core is set smaller than the refractive index of the second core, and only the first core is doped with a rare earth element, thereby suppressing the in...

A rare earth bonded magnet comprising a rare earth magnet powder bonded with a binder resin is manufactured by extrusion or injection molding. A rare earth bonded magnet manufactured by extrusion molding has a rare earth magnet powder content of 78.1 to 83.0 percent by volume. A rare earth bonded magnet manufactured by injection molding has a rare earth magnet powder content of 68.0 to 76.0 percent by volume. Preferably, the rare earth metal powder is at least one of Sm--Co alloys, R--Fe--B allo...

The method for producing a rare-earth sintered magnet of the present invention includes the steps of: compacting alloy powder for the rare-earth sintered magnet to form a green compact; loading the green compact into a case having a structure restricting a path through which gas flows between the outside and inside of the case, and placing a gas absorbent at least near the path; and sintering the green compact by heating the case including the green compact inside in a decompressed atmosphere.

Rare earth elements, added to the raw materials mixture fed to a cement kiln, produce cement compositions having increased early compressive strengths. Preparation of such cements requires less grinding of clinkers to achieve equivalent early strengths than similar compositions without the rare earth elements.

A rare earth borate in the form of substantially spherical, uniform diameter particles having an average particle diameter of 0.5-2 .mu.m is prepared by mixing substantially spherical rare earth oxide co-precipitates having an average particle diameter of 0.5-2 .mu.m with boric acid or boron oxide, and heating the mixture at 600-1100.degree. C. for reaction. It is a useful raw material for phosphor manufacture.

A rare earth element doped composition having a dopant concentration of up to about 60 mole percent of one or more rare earth elements selected from Tb, Dy, Ho, Er, Tm, Yb and Lu, wherein the composition is optically transparent to wavelengths at which excitation, fluorescence or luminescence of the rare earth elements occur. Method for making the compositions, composite materials having dispersed therein the compositions and luminescent devices containing optical or acoustical elements formed f...

Rare earth oxides can be reduced to rare earth metals by a novel, high yield, metallothermic process. The oxides are dispersed in a suitable, molten, calcium chloride bath along with sodium metal. The sodium reacts with the calcium chloride to produce calcium metal which reduces the rare earth oxides to rare earth metals. The metals are collected in a discrete layer in the reaction vessel.

The present invention presents novel leptospiral membrane lipoproteins, LipL1 and LipL2, associated with pathogenic strains of Leptospira. LipL1 is of about 35 kDa, and LipL2 is of about 41 kDa. Also disclosed are the method for purifying these proteins from Leptospira, their nucleotide and amino acid sequences, the cloning of the genes encoding the proteins and their recombinant proteins, methods for producing antibodies to these proteins, the resulting antibodies. These proteins, their immunog...

Rare-earth metal salts of organic carboxylic acids of this invention constitute themselves phosphors which exhibit unusually high luminescence efficiency, excel in chemical and physical stability and weatherability, show high affinity for other chemical substances and promise extensive usefulness in the field of high-performance luminescent products.

A crucible comprising Al.sub.2O.sub.3 and at least one selected from rare earth oxides inclusive of Y.sub.2O.sub.3 as main components and characterized by firing at 500 1,800.degree. C., the distribution of the rare earth oxide at a higher proportion in a fine particle portion having a particle size of up to 0.5 mm than in a coarse particle portion having a particle size in excess of 0.5 mm, and the substantial absence of the reaction product of the rare earth oxide with Al.sub.2O.sub.3 is suita...