Abstract: A multi-bypass pulse tube refrigerator comprising a pressure wave generator, a regenerator, a heat exchanger of cold ends (cold finger), a pulse tube, an orifice means and a reservoir volume, connecting in serial. Matrix material made of material of high heat capacity is packed in the regenerator. Rectifying means are arranged at the ends of the pulse tube. The outlet of the pressure wave generator is connected with the hot end of the regenerator. The connection between the cold ends of the regenerator and the pulse tube forms the heat exchanger of cold ends. The reservoir volume is connected with the hot end of the pulse tube through the orifice means. Resistance means are properly arranged in the pulse tube, so as to for gas to pass through the pulse tube uniformly and smoothly. At least one bypass with a throttling means is provided to connect the regenerator and the pulse tube.

Abstract: A siliconized graphite for use in mechanical seals is provided. This material is prepared by reacting graphite at an elevated temperature ranging from 1800.degree. to 2100.degree. C. with silicon monoxide. Silicon monoxide is generated in rate-controlled fashion by reacting either silicon carbide and silica or silicon nitride and silica at an elevated temperature ranging from 1500.degree. to 1800.degree. C.Although the optimum temperature range for the SiO generation and the siliconization of graphite is different by 300.degree. C., size-controlled raw materials (silicon carbide, silicon nitride, and silica) and a unique sample loading method make the whole process occurred in situ and make the production of mechanical seals efficient. Size-controlling of the raw materials is essential for a constant supply of silicon monoxide in controlled fashion, and a unique sample loading method is essential to put the SiO generation and the siliconization of graphite within their optimum temperature ranges.

Abstract: A process for molding a transparent plastic substrate for a high-density information recording-reading system by injecting molten resin into a molding cavity defined by a pair of mold halves, characterized in that an axial dimension of the molding cavity is increased at least two times between the start of a shot of the molten resin and the end of the pressure-holding stage in an injection molding cycle.

Abstract: A solid catalyst composition for the vapor phase conversion of methanol and ethanol to higher linear primary alcohols (e.g., n-propanol) is made up of particles of an inert, high surface area support (e.g., gamma-aluminum oxide) impregnated with an inorganic base promoter (e.g., a basic salt of an alkali metal) and a platinum group metal (e.g., rhodium). The production of the higher linear primary alcohols is carried out by contacting a mixture of methanol, ethanol, and a carrier gas (e.g., synthesis gas) with the catalyst at a temperature of between 200.degree. and 400.degree.C. and pressure of between 1000 and 5000 p.s.i.g. at a space velocity of between 2000 and 10,000 hr.sup.-.sup.1.