摘要:
A levodione reductase having the following physical properties is provided: molecular weight: from about 142,000 to about 155,000±10,000 (consisting of four homologous subunits having a molecular weight of 36,000±5,000); co-factor: nicotinamide adenine dinucleotide (AND/NADH); substrate specificity: active on levodione; optimum temperature: about 15° C. to about 20° C. at pH 7.0; optimum pH: 7.5; and activator: K+, Cs+, Rb+, Na+ and NH4+. The levodione reductase according to the present invention produces actinol, an important intermediate for the production of zeaxanthin, from levodione. This enzyme may be produced from a microorganism belonging to the genus Corynebacterium, preferably the microorganism Corynebacterium aquaticum AKU 611 (FERM BP-6448) or a functional equivalent, subculture, mutant or variant thereof. Also provided is a process for producing the levodione reductase that includes cultivating a microorganism of the genus Corynebacterium in an aqueous medium under aerobic conditions, disrupting the cells of the microorganism and isolating and purifying the levodione reductase from the cell-free extract. A process for producing actinol from levodione is also provided that includes contacting levodione with levodione reductase in the presence of the reduced form of nicotinamide adenine dinucleotide or a cell-free extract of the microorganism, and then isolating the resulting actinol from the reaction mixture.
摘要:
A process is disclosed for producing with good productivity a cross-linked polyaspartic acid resin having biodegradability and high water absorbency. The process features inclusion of one of the following steps: (a) a polysuccinimide, which has been brought into a dispersed state by a dispersant, and a cross-linking agent are reacted to produce the cross-linked polyaspartic acid resin; (b) imide rings of a cross-linked polysuccinimide are subjected to a hydrolysis reaction while controlling a swelling degree of a resulting gel, whereby the cross-linked polyaspartic acid resin is produced; and (c) a gel of a cross-linked polysuccinimide, which has been obtained by reacting a cross-linking agent to a solution of a polysuccinimide in an organic solvent, is disintegrated to subject imide rings of the cross-linked polysuccinimide to a hydrolysis reaction, so that the cross-linked polyaspartic acid resin is produced. The process may also include one or both of the following steps as needed: (d) a gel of the cross-linked polyaspartic acid resin is washed with water and/or a water-miscible organic solvent; and (e) the polysuccinimide is produced using a basic amino acid as a cross-linking agent.
摘要:
An ohmic electrode for III-V compound semiconductors such as GaAs semiconductors which has practically satisfactory characteristics is disclosed. A non-single crystal InAs layer, Ni film, WSi film and W film are sequentially deposited on an n.sup.+ -type GaAs substrate by sputtering, etc. and subsequently patterned by lift-off, etc. to make a multi-layered structure for fabricating ohmic electrodes. The structure is then annealed first at, e.g. 300.degree. C. for 30 minutes and next at, e.g. 650.degree. C. for one second to fabricate an ohmic electrode.
摘要:
Disclosed is a permanent magnet which is suitable for use for a field system of an electric motor or the like and which is constituted by a single piece of magnetic material in which S and N poles are alternately continuously formed through non-magnetic flux regions or weak magnetic flux regions interposed therebetween, and further disclosed is a magnetization apparatus for magnetizing such a permanent magnet. The magnetization apparatus comprises a first magnetic flux generation unit provided on one surface of a single piece of magnetic material for generating N-pole magnetic flux, a second magnetic flux generation unit provided adjacently to the first magnetic flux generation unit on the one surface for generating S-pole magnetic flux, and a third magnetic flux generation unit provided between the first and second magnetic flux generation unit on the one surface for passing therethrough part of magnetic flux generated by the first and second magnetic flux generation unit and for generating magnetic flux for canceling the magnetic flux passing through the third magnetic flux generation unit, whereby N and S poles are formed in domains of an object to be magnetized opposite to the first and second magnetic flux generation units and non-magnetic flux regions or weak magnetic flux regions are formed in domains of the object to be magnetized opposite to the third magnetic flux generation unit.
摘要:
Disclosed herein are novel linear copolymers having weight average molecular weight of 500-30,000 and comprising structural units represented by the following formulae (I), (II), (III) and (IV): ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 mean individually an alkyl group having 4 or fewer carbon atoms and R.sub.4 denotes an alkyl, cycloalkyl, aralkyl or phenyl group, and multivalent metal salts thereof in each of which the multivalent metal forms the multivalent metal salt between carboxyl groups within the same molecule of the copolymer or between different molecules of the copolymer; color-developing agents comprising multivalent metal-modified resins of the copolymers; and color-developing sheets obtained by coating the color-developing agents on their surfaces.
摘要:
A mounting of semiconductor laser chip on a heat sink or metal mount is improved so as to enable high accuracy of position and direction. A heat sink or metal mount, on which a semiconductor laser chip is mounted, comprises two parts, namely a main mount or larger portion and a sub-mount or smaller portion. The semiconductor laser chip is soldered by a solder layer on the sub-mount utilizing a microscope so as to assure an accurate position and an accurate direction with respect to the sub-mount. Then, the sub-mount is soldered on the main mount by a solder layer with an accurate relation both in position and direction by engaging a linear ridge as a first engaging means provided on the upper face of the main mount with a straight groove and a rear end face as a second engaging means, or by engaging a square recess as a first engaging means and the square bottom of the sub-mount as a second engaging means with each other. As a result of the above-mentioned structure, accurate position and direction of the semiconductor laser chip with respect to the mount is easily obtainable with a high yield.
摘要:
A hollow dish with a discrete, meltable core such as a wax core includes top and bottom members welded to one another at their periphery, and a meltable, preferably wax core confined within an oxygen-free, water-free cavity between the top and bottom members. A method for making a hollow dish with such a core includes liquifying a meltable substance such as wax in an oxygen-free, water-free, inert atmosphere; cooling and solidifying the meltable substance to form a meltable core; placing the meltable wax core in the cavity inside a hollow dish; removing all oxygen and water from the core-containing cavity inside the hollow dish; and sealing the hollow dish to preclude escape of the wax core from the cavity and to preclude oxygen and water from entering the cavity.
摘要:
In a semiconductor laser which has epitaxial layers including an active layer on a semiconductor substrate, a buffer layer is formed neighboring the active layer, in order to prevent undesirable diffusion of a highly diffusing dopant (Zn) into the active layer from an adjacent layer such as the second clad layer. The buffer layer has the same conductivity as that of the adjacent layer, has a broader energy gap than the active layer, and the dopant of the buffer layer is less diffusing than that of the adjacent layer.
摘要:
A semiconductor apparatus in which a conducting path formed from organic semiconductor molecules as a material has a novel structure and exhibits high mobility, and a manufacturing method for fabricating the same are provided. Fine particles that include a conductor or a semiconductor and organic semiconductor molecules, are alternately bonded through a functional group at both terminals of the organic semiconductor molecules to form a conducting path in a network form such that the conducting path in the fine particles and the conducting path in the organic semiconductor molecules are two-dimensionally or three-dimensionally linked together. This conducting path includes no intermolecular electron transfer, and the mobility is not restricted by the intermolecular electron transfer, and therefore the mobility of the conducting path along the main chain in the organic semiconductor molecules (in the direction of the axis of the molecule), for example, displays a high intramolecular mobility due to delocalized π electrons can be fully utilized.