Abstract: A semiconductor laser capable of emitting blue or green light is disclosed. The semiconductor laser comprises an n-type ZnMgSSe cladding layer, an active layer, a p-type ZnMgSSe cladding layer, a p-type ZnSe contact layer and a p-type ZnTe contact layer which are stacked in this sequence on an n-type GaAs substrate. A p-side electrode is provided on the p-type ZnTe contact layer. An n-side electrode is provided on the back surface of the n-type GaAs substrate. A multiquantum well layer comprising quantum wells made of p-type ZnTe and barriers made of p-type ZnSe is provided in the depletion layer produced in the p-type ZnSe contact layer along the junction interface between the p-type ZnSe contact layer and the p-type ZnTe contact layer. Holes injected from the p-side electrode pass through the junction by the resonant tunneling effect through quantum levels formed in the quantum wells of the multiquantum well layer.

Abstract: A method for purification of an amino acid which comprises contacting an amino acid solution containing impurities with an ion exchange resin to selectively adsorb the amino acid onto the resin, eluting and recovering the adsorbed amino acid whereby the resin is contacted with the amino acid solution in countercurrent continuous multiple steps during adsorption and an eluent is contacted with the adsorbed resin in countercurrent continuous multiple steps during elution.

Abstract: A method of producing a p-type CdS wherein oxygen is doped into a CdS layer at a concentration in a range between 10.sup.16 and 10.sup.19 atomic/cm.sup.3.

Abstract: A semiconductor laser formed into a double hetero junction structure comprising an n-type cladding layer and a p-type cladding layer with an active layer interposed therebetween. The p-type cladding layer has a laminated structure consisting of a first cladding layer of (Al.sub.x Ga.sub.1-x)InP disposed on one side adjacent to the active layer and a second cladding layer of Al.sub.y Ga.sub.1-y As disposed on the reverse side. A deterioration prevention layer of Al.sub.z Ga.sub.1-y As is included in the first cladding layer at a position spaced apart from the second cladding layer by a predetermined thickness. In addition, the second cladding layer is partially removed, and a current stricture layer is formed at the removed portion. Due to the above design, the semiconductor layer is capable of retaining high reliability with certainty.

Abstract: There are provided an undercoat composition with excellent adhesiveness to both a resin coating layer and a metal layer, and a metal substrate coated with a resin composition. The undercoat composition and the resin-coated metal substrate offer excellent hot-water resistance and chemical resistance.

Abstract: The Sn based multilayer coated steel strip for container-use is improved by the provision of a novel underyling coating of ternary Fe-Ni-P alloy which, mainly because of the Ni component, ensures a uniform deposition of the Sn layer, and mainly because of the P and Fe contents ensure a satisfactory remaining amount of free Sn for improving the weldability. The steel strip has a thin Sn plated layer and a chromate coating layer on the underlying coating.

Abstract: A semiconductor laser device arranged so that at least one of cladding layers is formed of a thin AlGaInP layer having a larger energy band gap as compared with an active layer adjacent to the active layer and an AlGaAs layer having a high thermal conductivity as compared with that of the AlGaInP layer and the larger energy band gap as compared with the active layer, which is located between the AlGaInP layer and a heat sink, whereby a heat generated in the active layer is effectively radiated to the heat sink, thus the semiconductor laser being made capable of continuously emitting a laser light of a short wavelength at a room temperature.

Abstract: The Sn based multilayer coated steel strip for container-use is improved by the provision of a novel underlying coating of ternary Fe-Ni-P alloy which, mainly because of the Ni component, ensures a uniform deposition of the Sn layer, and mainly because of the P and Fe contents ensure a satisfactory remaining amount of free Sn for improving the weldability. The steel strip has a thin Sn plated layer and a chromate coating layer on the underlying coating.

Abstract: Novel 4-benzazonine derivatives and their salts, and processes for the preparation thereof are disclosed. These 4-benzazonine derivatives are represented by the following general formula: ##STR1## wherein R stands for --H, --OH or a lower alkoxy group such as --OCH.sub.3, R.sub.1 designates --H or a lower alkyl group such as --CH.sub.3 and --CH.sub.2 CH.sub.3, R.sub.2 indicates --H or a lower alkyl group such as --CH.sub.3, R.sub.3 stands for --H, a linear or branched, saturated or unsaturated alkyl group having 1 to 4 carbon atoms, a mono- or di-hydroxy lower alkyl group such as --CH.sub.2 OH and ##STR2## a saturated cyclic hydrocarbon group having 3 to 6 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms, and R.sub.4 designates --H, --OH or .dbd. 0. These compounds have medicinal effects, especially therapeutic activities on the central nervous system, such as analgesic, antitussive and sedative activities.

Abstract: Novel 4-Benzazonine derivatives and their salts, and processes for the preparation thereof are disclosed. These 4-benzazonine derivatives are represented by the following general formula: ##STR1## wherein R stands for --H, --OH or a lower alkoxy group such as --OCH.sub.3, R.sub.1 designates --H or a lower alkyl group such as --CH.sub.3 and --CH.sub.2 CH.sub.3, R.sub.2 indicates --H or a lower alkyl group such as --CH.sub.3, R.sub.3 stands for --H, a linear or branched, saturated or unsaturated alkyl group having 1 to 4 carbon atoms, a mono- or di-hydroxy lower alkyl group such as --CH.sub.2 OH and ##STR2## a saturated cyclic hydrocarbon group having 3 to 6 carbon atoms or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms, and R.sub.4 designates --H, --OH or = O. These compounds have medicinal effects, especially therapeutic activities on the central nervous system, such as analgesic, antitussive and sedative activities.