Abstract: A method for the machining of a work blank by thermal shock, comprising the steps of locally heating and fusing the portions of the work blank desired to be machined and subsequently injecting a liquefied gas of extremely low temperature into the fused portions for thereby causing the fused portions to contract by thermal shock and enabling the removal of the fused portions and consequently the machining of the work to be accelerated by the explosive gasifying action of the liquefied gas.

Abstract: In the manufacture of iron oxide flakes by the steps of mixing an aqueous ferric salt solution with an aqueous alkali solution for thereby inducing an amorphous precipitate and subjecting the precipitate to a hydrothermal treatment, iron oxide flakes of an increased flake size are obtained by adding boric acid or a salt thereof to the mixture prior to the step of hydrothermal treatment.

Abstract: A tunable optical device is produced by forming in the surface of a substrate a fan-shaped grating of continuously varying period by means of a holographic technique using a photoresist and twisted mirrors, coating the surface of the substrate containing the formed grating with a polyurethane film and diffusing a dye in the prescribed region of the resultant polyurethane film coated on the substrate. In the device of the construction described above, irradiation of the region having the fan-shaped grating with a laser light generates laser light beams whose wavelength is variable with the position at which the laser light impinges upon the region of the grating.

Abstract: A semiconductor capable of exhibiting an electron transfer effect in a high electric field is used as a Hall element. Application of a voltage large enough to give rise to an electron transfer effect to the current input electrodes of the Hall element brings about a decrease in the concentration of electrons contributing to the Hall effect occurring within the semiconductor, an increase in the Hall coefficient and a notable enhancement in the sensitivity of the Hall element.

Abstract: An indium oxide (III) film produced by a method which comprises first forming a film of indium oxide (I) and subsequently oxidizing the film.

Abstract: Possible sedimentation of finely powdered coal in colloidal fuel can be effectively prevented by subjecting the colloidal fuel to the action of an electric field and thereby allowing the viscosity of the colloidal fuel to be enhanced owing to the electroviscous effect brought about by the electric field.

Abstract: Highly heat-resisting ceramic fibers are manufactured either by simply coating the surface of ceramic fibers with at least one phosphorus compound or by further subjecting the resultant coated ceramic fibers to a heat treatment. The ceramic fibers having the surface coated with said phosphorus compound or the ceramic fibers having the phosphorus compound contained therein at a gradually decreasing concentration in the direction of increasing depth from the surface which are manufactured by the aforesaid method are capable of high resistance to heat.

Abstract: A reversibly photosensitive glass consisting of cadmium oxide, germanium dioxide, sodium oxide and thallous oxide. A reversibly photosensitive glass consisting of silicon dioxide, sodium oxide, cadmium oxide and thallous oxide.

Abstract: Fluoroalkyl pyridines are produced in high yields by causing pyridines to react with fluoroalkyl iodides in the atmosphere of ammonia gas.

Abstract: An electrode for the measurement of ionic activity, having a sensor film made preponderantly of a substance sensitive to the ion subjected to measurement and Urushi (Japanese lacquer). The sensor film of said electrode is manufactured by a method which comprises mixing the aqueous solution of said sensitive substance with Urushi (Japanese lacquer), molding the resultant mixture and causing the molded mixture to set.

Abstract: A thin coating of silver is formed fast on the surface of a nitride type ceramic article by coating the surface of the ceramic article with a mixture consisting of copper sulfide and kaolin, subjecting the coated article to a thermal treatment in a nitrogen-containing atmosphere at a temperature in the range of from 900.degree. to 1300.degree. C., then overcoating the thermally treated ceramic article with silver carbonate and heating the overcoated article again in the nitrogen-containing atmosphere at a temperature in the range of from 700.degree. to 900.degree. C.

Abstract: A given enzyme is immobilized by a method comprising the steps of mixing the enzyme with an azido compound and a high molecular compound as a carrier, forming the resultant mixture in a desired shape, drying the formed mixture and exposing the formed and dried mixture to light for thereby causing the enzyme to be bound to the azido group of the azido compound and to be bound to the high molecular compound.

Abstract: The element "lithium" has strong absorption lines near 6707.84 A and 3232.61 A and possesses specific isotope shifts at the respective absorption lines. With the aid of a laser capable of controlling the oscillation spectral width accurately to 0.01 A, the isotopes of this element are separated from each other by irradiating lithium atomic beam with a laser beam tuned to the absorption line of either of the isotopes, .sup.6 Li and .sup.7 Li, for thereby selectively exciting the isotope, ionizing the excited isotope along by irradiation with a laser beam having one photon energy enough to pump it from the excited state to the ionized state and separating the ionized isotope from the un-ionized isotope by means of a mass-filter.