Abstract: An insulating layer is formed on a semiconductor substrate, and a first resist layer having a first resist opening portion is formed on the insulating layer. Then, the insulating layer is etched thought the opening portion to expose the substrate. After removing the first resist layer, a second resist layer having second resist opening portions are formed. One of the second resist opening portions is provided to expose the substrate, and a recess is formed in the substrate through the opening portion. Further, the insulating layer exposed from the other of the second resist opening portions is removed. Then, an electrode member for gate, source, and drain electrodes is deposited on the substrate. As a result, variations in intervals between the gate and drain electrodes and between the gate and source electrodes can be reduced.

Abstract: An analog switching circuit comprises an insulated-gate field-effect transistor (Q20) having two n-type input-side and outpu-side semiconductor regions (201, 202) and a p-type semiconductor substrate region 203, for controlling conductiveness between an input terminal (IN) and an output terminal (OUT) based on a gate potential. A surge pulse detecting circuit (1020), responsive to an electric potential (Vi) of the input terminal (IN), produces a detection signal of a surge pulse equivalent to a forward bias of a PN junction formed between the semiconductor substrate region (203) and the input-side semiconductor region (201). A substrate potential setting circuit (1010) varies an electric potential of the semiconductor substrate region (203) in response to the electric potential (Vi) of the input terminal (IN) when aby detection signal is produced.

Abstract: A dynamic-pressure gas bearing structure includes a sleeve, a column-like shaft fitted to the sleeve, and a plurality of shallow grooves formed on the outer peripheral surface of the shaft and extending in the axial direction of the shaft. The shallow grooves are formed by grinding in which grains are aligned to the aforementioned axial direction. An optical deflection scanning apparatus is provided with such dynamic-pressure gas bearing structure.

Abstract: A slide member has a sliding surface made of ceramic and a has surface roughness of not more than 1.0 .mu.m in center line average roughness Ra. The ceramics includes a silicon nitride sintered body which contains crystal grains having a linear density of at least 35 per 30 .mu.m in length with a boundary phase volume ratio of not more than 15 volume %, and which contains pores of not more than 20 .mu.m in maximum diameter in a content of not more than 3%. In a method of manufacturing the slide member, it is possible to ensure smoothness of the sliding surface by grinding the sliding surface and thereafter heating the ceramic in an either an inert gas or atmospheric air. A slide member that can be used under severe sliding conditions of high-speed sliding or the like and that has excellent wear resistance is obtained.

Abstract: A dynamic-pressure gas bearing structure includes a columnar shaft made of a silicon-nitride-based ceramic sintered body, a hollow cylindrical sleeve opposed to the shaft as keeping a clearance in a radial direction, the sleeve being made of a silicon-nitride-based ceramic sintered body, and at least three flat face portions located on a peripheral surface of the shaft and at equal intervals to the circumference along the peripheral surface. The flat face portion includes a plurality of unit planes continuously formed at predetermined angles to a direction of the circumference on the peripheral surface of the shaft. The unit planes are formed so as to extend substantially in parallel with an axial direction of the shaft.

Abstract: A composite bearing structure that has a high rotational accuracy and that can withstand high-speed rotation comprises first bearing means, second bearing means, third bearing means and fourth bearing means. The first bearing means supports a radial impact force which is applied to a rotator during rotation, and is formed by an inner ring (1) and an outer ring (2) consisting of silicon nitride ceramics sintered bodies. The second bearing means supports an axial load which is applied to the rotator while maintaining a prescribed clearance with the rotator, and is formed by a magnetic bearing body of two permanent magnets (12) and (13) which are thrust-directionally opposed to each other. The third bearing means maintains the radial rotational accuracy of the rotator, and is formed by a radial dynamic pressure producing groove (5) which is formed in a cylindrical surface of the inner ring (1).

Abstract: A slide member has a sliding surface made of ceramic and has a surface roughness of not more than 1.0 .mu.m in center line average roughness Ra. ceramic includes a silicon nitride sintered body, which contains crystal grains having a linear density of at least 35 per 30 .mu.m in length with a boundary phase volume ratio of not more than 15 volume %, and which contains pores of not more than 20 .mu.m in maximum diameter in a content of not more than 3%. In a method of manufacturing the slide member, it is possible to ensure smoothness of the sliding surface by grinding the sliding surface and thereafter heating the ceramic in either inert gas or an atmospheric air. A slide member that can be used under severe sliding conditions of high-speed sliding or the like and that has excellent wear resistance is obtained.

Abstract: A coating agent comprising a particulate PVA having an average particle diameter of 0.01 to 1 .mu.m has excellent applicability through blade coaters or roll coaters.

Abstract: A heat-sensitive recording material with a heat-sensitive recording layer comprising a modified polyvinyl alcohol containing 2.5 to 8 mole % of a carboxyl group-containing monomer units and having a degree of saponification of 40 to 65 mole % and a viscosity average degree of polymerization. of 50 to 500; a dispersing agent comprising the above modified polyvinyl alcohol for heat-sensitive dyes or color developing agents that can make the heat-sensitive dyes form color upon heating; and a process for producing aqueous dispersions which comprises dispersing a heat-sensitive dye or a color developing agent that can make the heat-sensitive dye form color upon heating, in an aqueous medium with a dispersing agent of the above modified polyvinyl alcohol.

Abstract: A size for yarn which minimizes thread break is described. The size comprises an aqueous solution of (I) a polyvinyl alcohol resin, (II) a modified starch, and a water-soluble cellulose compound (III), wherein the components are related by the following equations:(I)/(II)+(III))=85/15 to 95/5, and(II)/(III)=20/80 to 80/20,while simultaneously satisfying the expressions0.27X-0.7.ltoreq.log.sub.10 Y.ltoreq.0.27X+0.6; and (1)20.ltoreq.Y.ltoreq.300; (2)(A)/(B).ltoreq.0.5 (3)where X is the solid concentration in % by weight, Y is viscosity in centipoise at 90.degree. C. and a shear rate of 10 sec.sup.-1, (A) is viscosity at 60.degree. C. and a shear rate of 10,000 sec.sup.-1 of an adjusted aqueous solution resulting from the adjustment of the viscosity to 100 centipoise at 60.degree. C. and a shear rate of 10 sec.sup.-1 with said compound ratio of each of the components kept constant, and (B) is viscosity of 100 centipoise at 60.degree. C. and a shear rate of 10 sec.sup.-1 of said adjusted aqueous solution.

Abstract: Provided are compositions comprising a saponified product of an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 80 mol % and a saponification degree of vinyl acetate component of at least 95 mol %, said composition containing 20 to 200 ppm as converted to alkali metal of an alkali metal acetate, 30 to 250 ppm of acetic acid, and 5 to 500 ppm as converted to phosphate ion of phosphoric acid or an alkali metal hydrogenphosphate, and having a content ratio of acetic acid/alkali metal acetate of 0.1 to 1 and the flow characteristic that the extrusion rate does not substantially increase for at least 10 hours in the relationship between the heating time and the extrusion rate with a capillary rheometer (Koka Flow Tester) at at least one temperature 10.degree. to 80.degree. C. above the melting point.

Abstract: A composite bearing structure can withstand high speed rotation has first, second and third bearing components. The first bearing component supports a radial impact force applied to a rotator during rotation, and is made of an inner ring (1) and an outer ring (2) of silicon nitride ceramic sintered bodies. The second bearing component supports an axial load applied to the rotator while maintaining a required clearance between itself and the rotator and is made of two permanent magnets (12, 13) positioned thrustdirectionally opposite to each other. The third bearing component maintains a radial rotational accuracy of the rotator, and is made of a radial dynamic pressure producing groove (5) provided on a cylindrical surface of the inner ring (1).

Abstract: Provided are compositions comprising a saponified product of an ethylene-vinyl acetate copolymer having an ethylene content of 20 to 80 mol % and a saponification degree of vinyl acetate component of at least 95 mol %, said composition containing 20 to 200 ppm as converted to alkali metal of an alkali metal acetate, 30 to 250 ppm of acetic acid, and 5 to 500 ppm as converted to phosphate ion of phosphoric acid or an alkali metal hydrogenphosphate, and having a content ratio of acetic acid/alkali metal acetate of 0.1 to 1 and the flow characteristic that the extrusion rate does not substantially increase for at least 10 hours in the relationship between the heating time and the extrusion rate with a capillary rheometer (Koka Flow Tester) at at least one temperature 10.degree. to 80.degree. C. above the melting point.