Abstract: A method for press-forming a glass preform includes the steps of applying positioning pressure to an upper mold as the temperature of the upper mold and a lower mold increase to set values, maintaining a first temperature difference between the upper and lower molds of at least 10.degree. C. and increasing the temperature of the glass preform to a value above its glass transition temperature. Additional steps include cooling the upper and lower molds at a rate of 30.degree. to 100.degree. C. per minute while maintaining a temperature difference between the upper and lower molds at at least the first temperature difference, applying pressure to the lower mold, and opening the upper and lower molds to release the formed optical element after the temperatures of the upper and lower molds decrease to below a set value and a temperature difference between the upper and lower molds becomes greater than the first temperature difference.

Abstract: A method for forming a superconducting circuit is disclosed, comprising the steps of forming a mask pattern on a superconducting layer, forming a covering layer, containing a modifying element for superconductor, on the resultant structure, diffusing the modifying element for a superconductor, which is contained in the covering layer, into the superconducting layer to modify a corresponding location to a nonsuperconducting layer. A method for forming a multi-layer superconducting circuit is also disclosed, comprising sequentially repeating the same steps as set forth above over a substrate.

Abstract: A method of manufacturing an optical element from glass material is accommodated between an upper member and a lower member of mold. The glass material is press-molded in a state and heated to a desired temperature, thereafter being cooled and released from the mold to form a product having a predetermined optical functional surface. When the product is released from the mold, the upper mold member is first lifted by a predetermined amount, where the product may adhere to the upper mold member. Upon or after releasing and falling of the molded product from the upper mold member due to its own weight or heat stress, the upper mold member is further caused to ascend and the mold is opened so that the molded product can be taken out.

Abstract: This specification discloses a mold for use for press-molding an optical element, characterized in that at least the molding surface of a mold base material is coated with an a-C:H film containing 5-40 atom % of hydrogen therein and having a film density of 1.5 g/cm.sup.3 or more, and with hard carbon film containing 0-5 atom % of hydrogen therein and having a spin density of 1.times.10.sup.18 spin/cm.sup.3 or less and a film density of 1.5 g/cm.sup.3 or more.

Abstract: A method for manufacturing a superconductive multilayer circuit has a first thin film forming step for forming a thin film, which is composed of superconductive material or a similar material thereto, on a substrate, a first circuit layer forming step for forming a superconductive circuit by discharging a specific component from a predetermined part of the thin film or implanting the component in the thin film, a second thin film forming step for forming a thin film, which is composed of a superconducting material or the simulant thereto, on the first circuit layer, and a second circuit layer forming step for forming a superconductive circuit by removing a specific component from a predetermined part of the thin film or implanting the component in the thin film.

Abstract: In a process for manufacturing an optical element, in which a molding material is put in molds and is heated and press-molded to manufacture an optical element, a preheating treatment of the molding material is performed before it is put in the molds at a reduced pressure and a temperature lower than a temperature during the press molding.

Abstract: In a method of molding an optical device by press-molding a glass preform by using molding dies, the press-molding process is executed under a mixed gas atmosphere of a nonoxidizer gas and a hydrocarbon gas.

Abstract: This specification discloses a mold for use for press-molding an optical element, characterized in that at least the molding surface of a mold base material is coated with an a-C:H film containing 5-40 atom % of hydrogen therein and having a film density of 1.5 g/cm.sup.3 or more. Other mold coating films also disclosed are a hydrogenated amorphous carbon film with an intermediate carbide layer between the film and the molding surface, and a hard carbon film containing 0-5 atom % of hydrogen therein and having a spin density of 1.times.10.sup.18 spin/cm.sup.3 or less and a film densisy of 1.5 g/cm.sup.3 or more.

Abstract: Applicants' invention relates to a method for dissolving a solute material in a container by contacting the solute with a solvent in another container. Applicants' method relies upon the difference in the specific gravities of the solvent and the solute to create a convection current between their respective containers. The material, either the solute or the solvent, having the larger specific gravity is placed above the material having the smaller specific gravity, and the two materials are brought into contact. The solute dissolves in the solvent, and the resulting solution, which has a lower or higher specific gravity than the solvent, causes a convection current which draws the heavier material down and the lighter material up. As the convection current proceeds, the undissolved solute continues to come into contact with fresh solvent accelerating the dissolution process.

Abstract: There is disclosed an apparatus for producing optical elements, provided with a conveyor for transporting carriers for materials of optical elements into an evacuatable process chamber, and with a heating system for the material supported by the carrier, a forming system for the material supported by the carrier while the material is heated by the heating system, and a system for depositing a thin film to the material formed by the forming system and supported by the carrier.

Abstract: A sintered alloy for a valve seat comprising, in weight percent, 0.5 to 1.7% C, 0.5 to 2.5% Ni, 3.0 to 8.0% Cr, 0.1 to 0.9% Mo, 1.0 to 3.8% W and 4.5 to 8.5% Co, the balance being substantially Fe provided by a base atomized powder; said alloy containing 8 to 14% by volume of 250 mesh or less C-Cr-W-Co-Fe and Fe-Mo hard grains and 6 to 13% by volume of cells, with the continuous cells being infiltrated by a copper alloy.

Abstract: A cylinder liner is provided with a white cast iron layer formed in its inner peripheral surface in an area surrounding the top dead center position of the piston, and a thermally created layer is formed underlying the white cast iron layer. The layers may be simultaneously formed by reheating portions of the substantially finished liner with a high density heat radiation source.

Abstract: A cylinder liner for an internal combustion engine has a white case iron layer formed by remelting and cooling a part or whole of areas of an outer peripheral surface of the cylinder liner. A thermally affected layer is also formed between the white cast iron layer and the parent material. This cylinder liner has improved anti-cavitation properties.

Abstract: A process for preparing benzenecarboxylic acids which comprises oxidizing at least one aromatic hydrocarbon selected from the group consisting of p-xylene, p-toluic acid and methyl p-toluate with a molecular oxygen-containing gas in the liquid phase in the substantial absence of a lower aliphatic carboxylic acid as a solvent, said oxidation reaction being carried out in the presence of, as a catalyst,(A) a cobalt compound soluble in the reaction system,(B) a manganese compound soluble in the reaction system, and(C) a bromine compound soluble in the reaction system.

Abstract: In a method of obtaining purified 2,6-naphthalenedicarboxylic acid dimethyl ester by vacuum distilling crude 2,6-naphthalenedicarboxylic acid dimethyl ester under conditions of application of heat, the improvement which comprises vacuum distilling a crude 2,6-naphthalenedicarboxylic acid dimethyl ester having an acid value (A.sub.f), as expressed in milligrams of KOH required for neutralizing the carboxyl groups contained in one gram of said crude 2,6-naphthalenedicarboxylic acid dimethyl ester, of from 1.0 to 50.

Abstract: A process for preparing dimethyl 2,6-naphthalenedicarboxylate, which comprises continuously esterifying 2,6-naphthalenedicarboxylic acid with methanol at a temperature of about 140.degree. to about 350.degree. C. in the presence or absence of an esterifying catalyst, said 2,6-naphthalenedicarboxylic acid being fed into an esterification reaction zone in the form of solid particles having a specific surface area of about 4,000 cm.sup.2 /g.

Abstract: A novel 1,3,5,7-naphthalenetetracarboxylic acid, an alkali salt thereof, or an ester thereof, and a novel process for preparation thereof, and method of effective purification thereof.