Abstract: The ultraviolet-curable organopolysiloxane composition comprises (A) a first organopolysiloxane having, in a molecule, at least one isopropenyloxysilyl-substituted ethyl or propyl group, (B) a second organopolysiloxane having, in a molecule, at least 2 silicon-bonded mercaptoalkyl groups, (C) an organosilicon compound having at leaast one vinyl group in a molecule and (D) a photosensitizer. The composition can be rapidly cured by exposure to ultraviolet light into a cured silicone rubber body without the problems and disadvantages in the conventional ultraviolet-curable silicone rubber compositions.

Abstract: A semiconductor memory device comprises four memory cells (4a, 6) arranged in point symmetry on a semiconductor substrate (1), and an insulating layer (10) covering the memory cells and having one contact hole (2) placed in the center of the point symmetry, with the contact hole enabling electrical connection to each of the memory cells.

Abstract: A hydraulic circuit for a construction machine which operates an actuator for working machine simultaneously with an actuator for working element without degrading the operation of the actuator for working machine. The hydraulic circuit comprises a first hydraulic pump, a first directional control valve connected to the first hydraulic pump and controlling an operation of the working machine actuator, a third directional control valve controlling an operation of the working element actuator, a second directional control valve connected to a second hydraulic pump, a first pilot operating device for controlling an operation of the first directional control valve and a second pilot operating device for controlling an operation of the third directional control valve.

Abstract: An organosilicon compound represented by the general formula (I): ##STR1## wherein R.sup.1 may be the same or different and represents an alkyl group having 1 to 8 carbon atoms; R.sup.2 and R.sup.3 may be the same or different and represents an alkylene group having 1 to 8 carbon atoms; and R.sup.4 represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms,and a process for preparing the same. This compound is useful for improving adhesive properties of UV curable silicone compositions and the like.

Abstract: A valve apparatus (1; 50; 60, 61; 90; 100) in which at least one flow control valve (21, 22; 63, 76; 101) is incorporated in a body block (20; 62, 82), and the flow control valve is connected in pilot lines (6-9) which connect a pilot valve (2) supplied with a pilot hydraulic fluid of a predetermined pressure set by a relief valve (19) and a pilot operated directional control valve (3) actuated in response to operation of the pilot valve, to permit free flow of the hydraulic fluid from the pilot valve to the directional control valve, but to restrict flow of the hydraulic fluid from the directional control valve to the pilot valve. The body block (20; 62, 82) is formed therein with a first passage (31; 52; 68, 81) connected to a return line (14; 71, 72, 86) for the relief valve (19).

Abstract: A hydraulic pilot operated directional control valve (30; 60; 70) in which at least one pilot hydraulic pressure chamber (40, 41; 76) is formed within a block (39; 64; 75) of a hydraulic pilot operating section (32, 33; 61; 72), and pilot hydraulic fluid is led into the pilot hydraulic pressure chamber to drive a spool (37, 38; 74). A drain passageway (54; 82) is provided in the vicinity of the pilot hydraulic pressure chamber (40, 41; 76) within the block (39; 64; 75), and the pilot hydraulic pressure chamber and the drain passageway communicate with each other through minute passageway means (52, 53; 83) for bleeding air.

Abstract: An organosilicon compound represented by General Formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 may be the same or different, and each represent a substituted or unsubstituted monovalent hydrocarbon group, x and y each represent an integer of 1 to 3, and n is an integer of 0 or more.This compound is useful as a starting material for ultraviolet curable silicone compositions and room temperature curable silicone compositions.

Abstract: A pilot hydraulic system comprises a directional control valve having at least one pilot chamber for controlling the operation of a hydraulic actuator; and a pilot valve connected through a pilot line to the pilot chamber of the directional control valve for operation thereof. The pilot line includes a flow control valve which allows a free flow of hydraulic fluid from the pilot valve to the directional control valve while limiting a flow of hydraulic fluid from the directional control valve to the pilot valve.

Abstract: The fluoran compounds of the formula (I) are new red color forming chromogenic dyes. ##STR1## wherein R represents an isobutyl or isopentyl group, R.sub.1 represents a hydrogen or halogen atom or an alkyl group, R.sub.2 represents a hydrogen or halogen atom or an alkyl group, R.sub.3 represents a hydrogen atom, and R.sub.4 represents a hydrogen atom, or R.sub.4 and R.sub.1 as well as R.sub.2 and R.sub.3 taken together with the carbon atoms to which they are attached may form a benzene ring which may be substituted with a halogen atom. They are used, together with an acidic developer, in chromogenic recording materials for use in pressure sensitive copying paper, heat-sensitive recording paper and thermo-sensitive, reversible color changing composition.

Abstract: The fluoran compounds of the formula (I) are new red color forming chromogenic dyes. ##STR1## wherein R represents an isobutyl or isopentyl group, R.sub.1 represents a hydrogen or halogen atom or an alkyl group, R.sub.2 represents a hydrogen or halogen atom or an alkyl group, R.sub.3 represents a hydrogen atom, and R.sub.4 represents a hydrogen atom, or R.sub.4 and R.sub.1 as well as R.sub.2 and R.sub.3 taken together with the carbon atoms to which they are attached may form a benzene ring which may be substituted with a halogen atom. They are used, together with an acidic developer, in chromogenic recording materials for use in pressure sensitive copying paper, heat-sensitive recording paper and thermo-sensitive, reversible color changing composition.

Abstract: A method of winding a predetermined length of magnetic recording tape from a large reel (on which the tape is initially wound), onto a small reel, in which the running speed of the tape is gradually increased at the beginning stage of each winding cycle to a predetermined high speed, is subsequently kept at the high speed, and is gradually slowed down near the end of the cycle, and then the tape is finally stopped to end the cycle. Simultaneously with the beginning of each winding cycle, an encoder begins to generate a pulse train, the number of pulses of which is in proportion to the number of rotations of the small reel. The number of pulses in the pulse train is counted and the tape running speed is gradually slowed down when the number of pulses counted reaches a predetermined value according to the time at which the tape running speed is to be gradually slowed down.