Abstract: A thin film transistor structure for use in driving liquid crystal display elements has a semiconductor active layer, a control electrode layer underlying the active layer with an insulating layer interposed therebetween and first and second main electrode layers formed on or above the active layer in a spaced relation with each other to define a channel in the active layer in cooperation with the control electrode layer between the main electrode layers. The active layer has a first peripheral edge portion generally perpendicular to the direction of the channel and a second peripheral edge portion generally not perpendicular to the direction of the channel. The first and/or second main electrode layer extends over the first and/or second peripheral edge portion of the active layer such that at least a part of the first peripheral edge portion and/or at least part of the second peripheral edge portion of the active layer has its side face directly covered with the main electrode layer.

Abstract: Disclosed are a thin film transistor comprising a first electrode pattern formed on an insulating substrate as a gate electrode, a first insulating film formed as a gate insulating film and covering at least the electrode pattern, a semiconductor thin film pattern mainly composed of silicon formed on the insulating film, the semiconductor thin film pattern overlapping the first electrode pattern and the existing region thereof being limited, second and third electrodes formed on the semiconductor thin film pattern as a drain electrode and a source electrode, the second and third electrodes covering a portion of the semiconductor thin film pattern and being spaced apart each other, and a thin film containing silicon oxide formed over the semiconductor film, the second and third electrodes being formed upon the silicon oxide film, a method of manufacturing the thin film transistor, an active matrix circuit board using the thin film transistors, and an image display device using the active matrix circuit board.

Abstract: .beta.-Chloroalanine is prepared by reacting in an aqueous medium an aziridine-2-carboxylate with hydrogen chloride in an amount of 2.0-5.0 moles per mole of the aziridine-2-carboxyalte and causing the thus-formed .beta.-chloroalanine to selectively crystallize out from the liquid reaction mixture. Since the solution recovered after the isolation of the crystallized .beta.-chloroalanine still contains .beta.-chloroalanine and by-produced .alpha.-chloro-.beta.-alanine dissolved therein, they may be converted into an aziridine-2-carboxylate by treating them with a base to recirculate it for reuse.

Abstract: DL-cystein is produced by reacting a .beta.-halogenoalanine with a trithiocarbonate to obtain the mono(aminocarboxyethyl) ester of trithiocarbonate and then subjecting the ester to acid decomposition. The above process requires mild reaction conditions, is easy to carry out its reactions and can afford DL-cystein with high yield. It is thus an excellent production process of DL-cystein from the industrial viewpoint.

Abstract: A process for producing aziridine-2-carboxylic acid or its salts is provided which comprises treating an alpha-halogeno-beta-aminopropionitrile or its mineral acid salt with an alkali or alkaline earth metal hydroxide in water or in a water-containing organic solvent. In a preferred embodiment, aziridine-2-carboxylic acid or its salt is produced by treating the reaction mixture containing an alpha-halogeno-beta-aminopropionitrile obtained by reacting an alpha, beta-dihalogenopropionitrile or an alpha-halogenoacrylonitrile with ammonia, with an alkali or alkaline earth metal hydroxide in the presence of water without isolating the alpha-halogeno-beta-aminopropionitrile from the reaction mixture beforehand.

Abstract: A process for producing a 2,3-dihalopropionitrile is provided which comprises directly halogenating acrylonitrile with a halogenating agent in the presence of a carbonate, hydrogen carbonate or hydrogen phosphate of an alkali or alkaline earth metal and in the absence of positive irradiation of light.

Abstract: Production of DL-serine by heating a strong acid type cation exchange resin having aziridine-2-carboxylic acid absorbed thereto. Specifically, an industrial process for producing DL-serine is provided which comprises treating an alpha-halogeno-beta-aminopropionitrile or its mineral acid salt in water or a water-containing organic solvent with an alkali or alkaline earth metal hydroxide to form an alkali or alkaline earth metal aziridine-2-carboxylate, treating the reaction mixture with a strong acid type cation exchange resin to cause adsorption of aziridine-2-carboxylic acid, and thereafter heating the cation-exchange resin.