摘要:
A centrifugal compressor has a plurality of seals arranged at the back of an impeller for sealing the impeller outlet and form an annular space defined at the back of the impeller. The annular space is fed with a cold gas under a higher pressure than that of the air discharged at the impeller outlet. Thus, the back of the impeller is cooled down.
摘要:
The present invention is intended to provide a method of growing a silicon monocrystalline rod by an FZ process, wherein the dopant distribution of the silicon monocrystalline rod in the diametrical direction is made microscopically uniform, characterized in that a magnetic field forming means is arranged above and/or below a melting zone of said silicon monocrystalline rod to surround said silicon monocrystalline rod and a magnetic field is applied to the melting zone of the silicon monocrystalline rod through said magnetic forming means, and preferably the magnetic field forming means is constituted by supplying a direct electric current through a solenoid coil surrounding said silicon monocrystalline rod.
摘要:
On an apparatus for developing latent images of diazotype prints with a developer liquid containing an organic amine or amines as the developing agent, the tendency of the diazotype paper to curl and wind round the applicator roller is effectively precluded by the addition of a very small amount of a fluorocarbon non-ionic surface active agent. The amount of the agent is preferably in the range from 0.01 to 1% of the total weight of the developer composition.
摘要:
A coating composition contains (A) a water-based emulsion containing (a) amino group-containing polyorganosiloxane having a self crosslinking property, (b) chlorinated polyolefin, and (c) a water dispersible polyurethane resin, and (B) spherical particles made up of a rubbery elastic body mixed and dispersed in the water-based emulsion (A). The water-based emulsion (A) can be obtained by mixing a first emulsion containing the amino group-containing polyorganosiloxane (a), a second emulsion containing the chlorinated polyolefin (b), and the water dispersion of the polyurethane resin (c). The coating composition can form a coating film excellent in preservation stability, coating uniformity, working life, having good non-tackness, water repellancy, lubricity, and excellent in adhesiveness and abrasion resistance.
摘要:
To provide a balloon catheter having a flexible and highly expandable balloon so as to prevent the inner wall of the blood vessel from being damaged by the passage of the balloon In a balloon catheter aimed to be stayed in a blood vessel and to be used mainly for the occlusion of a blood vessel, the balloon comprises a material selected from materials which have sufficient flexibility for preventing a blood vessel blocking operation from giving a damage to a vascular wall, have sufficient elasticity with its shrink characteristics when removing the catheter, and prevent a thrombus due to a direct contact to blood; and a maximum stretching of the material of said balloon in the state stayed in the blood vessel is defined so as to exceed a maximum stretching of said balloon itself.
摘要:
By utilizing a crystal pulling apparatus for producing a single crystal according to the Czochralski method comprising at least a crucible to be charged with a raw material, a heater surrounding the crucible, and subsidiary heating means provided below the crucible, a single crystal is pulled or the raw material is additionally introduced with heating by the heater surrounding the crucible and the subsidiary heating means when the amount of the raw material melt in the crucible becomes a limited amount. Thus, there is provided a method for growing a single crystal at a high yield while preventing solidification of melt raw material decreased to a limited amount without affecting crystal quality, durability of crucible or the like even when a crucible having a large diameter is used.
摘要:
According to the present invention, there are provided a silicon wafer, wherein an epi-layer is not formed on a surface, and number of LSTDs having a size of 50 nm or more existing in a surface layer portion is 0.24 number/cm2 or less; a method for determining production conditions of a silicon single crystal, which comprises pulling nitrogen-doped silicon single crystals by the CZ method while varying V/G and/or PT, producing silicon wafers from the silicon single crystals, subjecting the silicon wafers to a heat treatment, determining acceptability of the wafers based on a predetermined characteristic value, obtaining correlation between the acceptability and V/G and PT, and determining production conditions based on the correlation; and a method for producing a silicon wafer comprising pulling a silicon single crystal so that V/G and PT should be lower than V/G and shorter than PT that are uniquely defined by predetermined nitrogen concentration and oxygen concentration in the silicon single crystal, conditions of heat treatment to which the silicon wafer is subjected, and grown-in defect density of the silicon wafer. According to the present invention, a nitrogen-doped annealed wafer showing a low defect density even under severe examination conditions and little fluctuation thereof depending on the production condition is produced.
摘要:
A flexible tube having a laminated multi-layer structure including an outer layer composed of a main tube body layer formed of thermoplastic synthetic resin in a predetermined thickness and a reinforcing layer provided on the inner side of the main tube body layer, and an inner layer formed of a thin film sheet of air tight and low friction material. The inner layer is formed by rolling an elongated strip of a thin film sheet into a tubular form such that opposite lateral sides of the thin film sheet are overlapped one on the other to provide a thick wall portion extending longitudinally of and at one angular position of the inner layer.
摘要:
A method for producing a silicon single crystal in accordance with CZ method, characterized in that before producing the crystal having a predetermined kind and concentration of impurity, another silicon single crystal having the same kind and concentration of impurity as the crystal to be produced is grown to thereby determine an agglomeration temperature zone of grown-in defects thereof, and then based on the temperature, growth condition of the crystal to be produced or temperature distribution within a furnace of a pulling apparatus is set such that a cooling rate of the crystal for passing through the agglomeration temperature zone is a desired rate to thereby produce the silicon single crystal. A silicon single crystal produced in accordance with the above method, characterized in that a density of LSTD before subjecting to heat treatment is 500 number/cm2 or more and the average defect size is 70 nm or less. The present invention provides by CZ method a silicon single crystal and a silicon wafer wherein the dispersion in size and density of grown-in defects is suppressed effectively and the quality is stabilized regardless of the variety of crystals, and a producing method therefor.
摘要翻译:根据CZ方法制造单晶硅的方法,其特征在于,在制造具有预定种类和浓度的杂质的晶体之前,生长具有与待生产的晶体相同种类和杂质浓度的另一硅单晶 从而确定其生长缺陷的附聚温度区,然后基于温度,将要生产的晶体的生长条件或拉制装置的炉内的温度分布设定为使得用于 通过附聚温度区域是所需的速率,从而产生硅单晶。 根据上述方法制备的硅单晶,其特征在于,在热处理之前的LSTD的密度为500个数/ cm 2以上,平均缺陷尺寸为70nm以下。 本发明通过CZ法提供了硅单晶和硅晶片,其中无论晶体的种类如何,有效地抑制了生长缺陷的尺寸和密度的分散,并且质量稳定,并且其制造方法。
摘要:
In method for manufacturing a silicon single crystal in accordance with a Czochralski method, during the growth of the silicon single crystal, pulling is performed such that a solid-liquid interface in the crystal, excluding a peripheral 5 mm-width portion, exists within a range of an average vertical position of the solid-liquid interface ±5 mm. There is also disclosed a method for manufacturing a silicon single crystal in accordance with the Czochralski method, wherein during the growth of a silicon single crystal, a furnace temperature is controlled such that a temperature gradient difference &Dgr;G (=Ge−Gc) is not greater than 5° C./cm, where Ge is a temperature gradient (° C./cm) at a peripheral portion of the crystal, and Gc is a temperature gradient (° C./cm) at a central portion of the crystal, both in an in-crystal descending temperature zone between 1420° C. and 1350° C. or between a melting point of silicon and 1400° C. in the vicinity of the solid-liquid interface of the crystal. The method maintains high productivity and enables a silicon single crystal and silicon wafers to be manufactured such that a defect density is very low over the entire crystal cross section, and the oxygen concentration distribution over the surface of each silicon wafer is improved.