Abstract: A Light-emitting diode having improved moisture resistance characteristics comprises a p-type gallium arsenide substrate and four epitaxial layers of Al.sub.x Ga.sub.1-x As (22, 23, 24 and 25). These epitaxial layers comprises an intervening layer (22) of p-type Al.sub.x1 Ga.sub.1-x1 As, a cladding layer (23) of p-type Al.sub.x2 Ga.sub.1-x2 As, an active layer (24) of Al.sub.x3 Ga.sub.1-x3 As, and a window layer (25) of Al.sub.x4 Ga.sub.1-x4 As so as to form a double-hetero structure, where x1, x2, x3 and x4 represent mixed crystal ratios of aluminum to arsenic of the layers, respectively, and meet the condition that:x2.gtoreq.x4>x1.gtoreq.x3 (0.ltoreq.x1, x2, x3, x4.ltoreq.1).

Abstract: A light-emitting diode having improved moisture resistance characteristics comprises a p-type gallium arsenide substrate and four epitaxial layers of Al.sub.x Ga.sub.1-x As (22, 23, 24 and 25). These epitaxial layers comprises an intervening layer (22) of p-type Al.sub.x Ga.sub.1-x As, a cladding layer (23) of p-type Al.sub.x2 Ga.sub.1-x2 As, an active layer (24) of Al.sub.x3 Ga.sub.1-x3 As, and a window layer (25) of Al.sub.x4 Ga.sub.1-x4 As so as to form a double-hetero structure, where x1, x2, x3 and x4 represent mixed crystal ratios of aluminum to arsenic of the layers, respectively, and meet the condition that:x2.gtoreq.x4>x1.gtoreq.x3 (0.ltoreq.x1, x2, x3, x4.ltoreq.1).

Abstract: A retainer for a needle bearing has an improved durability owing to the improved strength of its stay portions at the roots thereof, and an improved lubricating property. The retainer 10 is made by forming a plurality of longitudinally spaced apart pockets 11 for needle rollers in a strip of material, bending it into a cylindrical shape and joining its butt ends together. Every two adjoining pockets 11 define therebetween a stay portion 13 having a pair of axially extending sides S which are substantially parallel to each other. Every two adjoining stay portions 13 have between their radially inner ends a distance L1 which is smaller than the diameter of each needle roller 9f. Each stay portion 13 has a pair of protrusions 14 extending from its axially middle and radially outer part to the centers of two adjoining pockets 11, and the protrusions 14 in each pocket 11 have therebetween a distance L2 which is smaller than the diameter of the needle roller 9.

Abstract: An emission spectrum controlling apparatus and method for an LED are disclosed. A temperature measurement device is provided for measuring the temperature of a light emitting diode or the temperature in the surrounding environment of the light emitting diode. A driving power control device is also provided for controlling the driving power of the LED, and a computing unit is disclosed which controls the driving power control device based on the temperature information from the temperature measuring device and the driving power information from the driving power control device.

Abstract: On the surface of n-type layer of Ga.sub.1-x Al.sub.x As (0.ltoreq..times..ltoreq.1) having n-type layer, Au layer is formed as a first layer, and alloying treatment is performed after Ge layer, Ni layer and Au layer are sequentially formed. The first Au layer, the second Ge layer, the third Ni layer and the fourth Au layer have the following thickness:______________________________________ 1st layer Au 10-100 .ANG. 2nd layer Ge 50-200 .ANG. 3rd layer Ni 50-200 .ANG. 4th layer Au 200-1000 .ANG. ______________________________________Thus, it is possible to form an ohmic electrode, which has low contact resistance and does not develop ball-up phenomenon.

Abstract: On the surface of n-type layer of Ga.sub.1-x Al.sub.x As (0.ltoreq.x.ltoreq.1) having n-type layer, Au layer is formed as a first layer, and alloying treatment is performed after Ge layer, Ni layer and Au layer are sequentially formed. The first Au layer, the second Ge layer, the third Ni layer and the fourth Au layer have the following thickness:______________________________________ 1st layer Au 10-100 .ANG. 2nd layer Ge 50-200 .ANG. 3rd layer Ni 50-200 .ANG. 4th layer Au 200-1000 .ANG. ______________________________________Thus, it is possible to form an ohmic electrode, which has low contact resistance and does not develop ball-up phenomenon.

Abstract: The present invention provides:(1) a solvent composition comprising chloropentafluoropropane and 1,1-dichloro-1-fluoroethane; and(2) a solvent composition comprising chloropentafluoropropane and dichlorotrifluoroethane.

Abstract: An ultrasonic motor driving circuit has a drive duty generating circuit that intermittently outputs a drive request signal according to the battery voltage, and a drive signal output means that receives the drive request signal to output a drive signal. The drive signal is in the form of bursts with pause intervals, the pause intervals being variable with a change in the battery voltage thereby improving utilization of the battery capacity.

Abstract: A refrigerant comprising (1) dichlorotrifluoroethane and (2) at least one compound selected from the group consisting of chlorotetrafluoroethane, pentafluoroethane, tetrafluoroethane, 1-chloro-1,1-difluoroethane, 1,1,1-trifluoroethane and 1,1-difluoroethane.

Abstract: The invention provides a dehydrating agent comprising at least one of fluorine-containing alcohols; a dehydrating agent comprising at least one of fluorine-containing alcohols and water; and a method of dehydrating and drying an article having a surface moistened with residual water, the method comprising immersing the article in a dehydrating agent comprising at least one of fluorine-containing alcohols or comprising at least one of fluorine-containing alcohols and water, and drying the article after the immersion.

Abstract: The present invention provides an oil for a refrigerating machine using a hydrogen-containing halogenated hydrocarbon as a refrigerant, the oil comprising a fluorine-containing polyether having repeated units represented by the formula(--CF.sub.2 CF.sub.2 CF.sub.2 O).sub.l (CHFCF.sub.2 CF.sub.2)).sub.m (CH.sub.2 CF.sub.2 CF.sub.2 O).sub.

Abstract: According to the present invention, roughness are formed on the surface of III-V group compound semiconductor to prevent total reflection, and SiNx film is formed on rough surface. This makes it possible to increase external quantum efficiency by surface roughness. Further, bond strength is increased because SiNx film is furnished on the roughness. As the result, the detachment of SiNx film is prevented, moisture resistant property is improved, and service life of LED is extended by preventing oxidation.

Abstract: The present invention provides a refrigerant comprising 1,1,1-trifluoroethane and either chlorotetrafluoroethane or tetrafluoroethane.

Abstract: The present invention provides a refrigerant comprising tetrafluoroethane and either chlorodifluoromethane or chlorodifluoroethane.

Abstract: A refrigerant comprising (1) dichlorotrifluoroethane and (2) at least one compound selected from the group consisting of chlorotetrafluoroethane, pentafluoroethane, tetrafluoroethane, 1-chloro-1,1-difluoroethane, 1,1,1-trifluoroethane and 1,1-difluoroethane.

Abstract: A refrigerant comprising chloro-difluoromethane and 1,1,1-trifluoroethane.

Abstract: A substrate for a high-intensity LED and the method of epitaxially growing the substrate according to the invention are based on the fact that, in using an AuZn alloy or the like as the ohmic electrode of the p-type Al.sub.x Ga.sub.1-x As layer (2), the higher the carrier concentration of this layer, the smaller the contact resistance and the lower the applied voltage (V.sub.F) necessary for passing a forward current of 10 mA. Joint use is made of gas-phase epitaxy and liquid-phase epitaxy. A layer having a carrier concentration three to five times that of an epitaxial layer formed by liquid-phase epitaxy (LPE) can be realized with excellent reproducibility by gas-phase epitaxy (MOCVD process, MBE process, etc.). By utilizing this p-type Al.sub.x Ga.sub.1-x As layer (2) as an electrode contact layer, contact resistance can be reduced and variance diminished.

Abstract: An epitaxial layer having a double-hetero structure is forming using an MOCVD process or an MBE process, and an epitaxial substrate is formed using an LPE process, thereby forming a substrate which exploits the distinguishing features of both processes. Since the MOCVD process or MBE process exhibits mixed-crystal ratio and film thickness controllability, excellent reproducibility and uniformity are obtained when forming the double-hetero structure on a compound semiconductor substrate. Since the growth process takes place under thermal non-equilibrium, the amount of impurity doping is raised to more than 10.sup.19 cm.sup.3. This is advantageous in terms of forming an electrode contact layer. With the LPE process, the material dissolved in the melt is grown epitaxially on the substrate by slow cooling, and the rate of growth is high. This process is suitable for forming the substrate after removal of the compound semiconductor substrate.

Abstract: The invention provides a working fluid for Rankine cycle comprising 1,2-dichloro-1,1,2,-trifluoro-ethane; and a process for converting thermal energy into mechanical energy in the Rankine cycle in which a cycle is repeated comprising the steps of vaporizing a working fluid comprising 1,2-dichloro-1,1,2-trifluoroethane with a hot heat source, expanding the resultant vapor in an expansion device, cooling it with a cold heat source to condense and compressing it by a pump.

Abstract: The present invention polishes the surface of a substrate or epitaxial layer of Al.sub.x Ga.sub.1-x As wherein 0<x<1.0 with a polishing liquid comprising an aqueous alkali hypochlorite solution or a mixture of said aqueous solution with an alkali carbonate, said liquid being regulated to a pH value ranging from 8.0 to 11.0, and further containing a powder such as SiO.sub.2 or a colloidal material such as colloidal silica having a fine particle size to afford a planar mirror-surface to said surface, thereby preventing wafer cracking or pattern flowing during patterning by photomasks and improving yields.