Abstract: A first aspect of the present invention is carbon fiber wherein the surface of a monofilament has a center line average roughness Ra of 6.0 nm or more and 13 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. A second aspect of the present invention is carbon fiber precursor acrylic fiber wherein the surface of a monofilament has a center line average roughness Ra of 18 nm or more and 27 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. The carbon fiber according to the first aspect is obtained by stabilizing and carbonizing under specific conditions the carbon fiber precursor acrylic fiber according to the second aspect.

Abstract: Disclosed is an observable centrifugal apparatus capable of checking in real time a state of a sample during reaction of separation or synthesization in the form of a stable and high-quality image at a high frame rate. An observable centrifugal apparatus A has a rotary disc 4 rotating about a rotary shaft 2, a reactor 6 disposed on the rotary disc and rotating together with the rotary disc while accommodating a sample, and a microscope 8 for observing a state of the sample within the reactor, in which predetermined substances of the sample are separated or synthesized by applying a centrifugal force to the sample within the reactor.

Abstract: Disclosed is an observable centrifugal apparatus capable of checking in real time a state of a sample during reaction of separation or synthesization in the form of a stable and high-quality image at a high frame rate. An observable centrifugal apparatus A has a rotary disc 4 rotating about a rotary shaft 2, a reactor 6 disposed on the rotary disc and rotating together with the rotary disc while accommodating a sample, and a microscope 8 for observing a state of the sample within the reactor, in which predetermined substances of the sample are separated or synthesized by applying a centrifugal force to the sample within the reactor.

Abstract: A guide rail 13 is formed of a ceramic material having a specific strength of 2×107 mm or more and has a planar part with a surface roughness of 0.5 ?mRa or less. Further, the guide rail 13 has a recess 18 for avoiding interference with a part to be attached in which the corner 18a of the recess 18 is formed with a radius of curvature of 0.1 mm or more.

Abstract: The present invention provides a rolling element capable of ensuring excellent corrosion resistance, and capable of maintaining a stable performance for a long time even in a case where a slight amount of a solution intrudes into the inside, with no occurrence of dry friction and the like between a rolling element and a raceway groove.

Abstract: A rolling bearing 1 comprises a inner ring 2 (as a movable member), an outer ring 3 (as supporter) for supporting the inner ring 2, and a plurality of rolling elements 4 disposed between the inner ring 2 and the outer ring 3. The rolling element are rotated in accordance with the rotation of the inner ring 2. The rolling bearing is to be located in the vicinity of a heat source. The outer ring 3 located nearer to the heat source than the inner ring 2 is composed with a material of a heat conductivity being 40 W/m·K or less.

Abstract: A guide rail 13 is formed of a ceramic material having a specific strength of 2×107 mm or more and has a planar part with a surface roughness of 0.5 &mgr;mRa or less. Further, the guide rail 13 has a recess 18 for avoiding interference with a part to be attached in which the corner 18a of the recess 18 is formed with a radius of curvature of 0.1 mm or more.

Abstract: A spacer type solid lubricating bearing disposing a spacer comprising a solid lubricating material, for example, graphite between each of rolling elements is proposed. A solid lubricating rolling bearing is provided with an inner ring, an outer ring, rolling elements, spacers of a material containing a solid lubricant comprising a selected material, and a cage with a pocket for accommodating at least one spacer and one rolling element as a unit.

Abstract: A rolling bearing 1 comprises a inner ring 2 (as a movable member), an outer ring 3 (as supporter) for supporting the inner ring 2, and a plurality of rolling elements 4 disposed between the inner ring 2 and the outer ring 3. The rolling element are rotated in accordance with the rotation of the inner ring 2. The rolling bearing is to be located in the vicinity of a heat source. The outer ring 3 located nearer to the heat source than the inner ring 2 is composed with a material of a heat conductivity being 40 W/m·K or less.

Abstract: A rolling part steel with which the strength of a rolling part of a cold-worked bearing is improved compared with that of a conventional turned part by controlling the length and number of sulfide inclusions in the steel to an optimal range, when a rolling part steel is prepared so that the maximum length of sulfide inclusions in the steel is 100 .mu.m or less and that a number of sulfide inclusions whose lengths exceed 40 .mu.m is 50 or less per unit area (160 mm.sup.2) , the roughness of its bore surface is improved to have a greater strength. As a result, for example, a thus formed raceway ring has a longer life against fatigue-induced cracks than a turned raceway ring.