摘要:
A process for producing an optically active amino alcohol is provided that includes a step in which a nitro ketone or a cyano ketone is reacted with a hydrogen-donating organic or inorganic compound in the presence of a transition metal compound catalyst having an optically active nitrogen-containing compound as an asymmetric ligand to give an optically active nitro alcohol or an optically active cyano alcohol, and a step in which the above optically active alcohol is further reduced to efficiently produce an optically active amino alcohol.
摘要:
A zoom optical system suited for use in an electronic image pickup apparatus comprising a first negative lens unit, a second positive lens unit and a third positive lens unit, in which a magnification is changed from a wide position to a tele position by moving at least the first lens unit and the second lens unit so as to change an airspace between the first lens unit and the second lens unit and widen an airspace between the second lens unit and the third lens unit, the second lens unit comprises a biconvex lens element and a cemented meniscus lens component having a convex surface on the object side, and each lens unit has a small thickness.
摘要:
In an apparatus for growing a semiconductor single crystal from semiconductor melt, a crucible retains the semiconductor melt. An electrode contacts with the semiconductor melt and applies current to the semiconductor melt. The electrode is formed of the same material as the semiconductor crystal.
摘要:
The object of the invention is to reduce the thickness of electronic image pickup equipment as much as possible, using a zooming mode having stable, high image-formation capabilities from an object at infinity to a near-by object. The electronic image pickup equipment comprises a zoom lens system comprising a negative, first lens group G1, a positive, second lens group G2 and a positive, third lens group G3. For zooming from the wide-angle end to the telephoto end of the zoom lens system upon focused on an object at infinity, the separation between G2 and G3 becomes wise. By moving G3 toward the object side of the system, the system can be focused on a nearer-by object. In the zoom lens system, the second lens group G2 comprises one positive lens 2a, one negative lens 2b and a lens subgroup 2c comprising at least one lens, and the third lens group G3 comprises one positive lens. The zoom lens system satisfies conditions with respect to the optical axis distance from the image-side surface of the positive lens 2a to the image-side surface of the negative lens 2b and the focal length ratio in air between the positive lens 2a and the lens subgroup 2c.
摘要:
A semiconductor substrate is provided which maintains its gettering capabilities throughout the manufacturing process of a semiconductor device and which prevents previously gettered contaminating impurities from being released again into an operating region of a semiconductor device. The semiconductor substrate includes a silicon substrate, a polysilicon layer, and a high density boron layer. The silicon substrate has a first main surface and a second main surface opposed to the first main surface, and the silicon substrate is used to form a semiconductor device at least indirectly on the first main surface. The polysilicon film is formed at least indirectly on the second main surface, and the high density boron layer is disposed between the silicon substrate and the polysilicon film. Also a ratio of a highest boron density value in the high density boron layer to a lowest boron density value in the silicon substrate is greater than or equal to approximately 100. Instead of using the high density boron layer, other layers may be used such as silicon oxide layers or polysilicon layers. Also, a method for manufacturing the semiconductor substrate is also provided.
摘要:
In an apparatus for growing a semiconductor crystal from semiconductor melt, a crucible retains the semiconductor melt. An electrode contacts with the semiconductor melt and applies current to the semiconductor melt. The electrode is formed of the same material as the semiconductor crystal.
摘要:
A plurality of honeycomb pipes bundling a plurality of fine tubes are inserted and fixed at desired positions in a refrigerant piping at proper intervals to form a silencer, and noise is reduced by straightening and homogenizing the disturbance of refrigerant and attenuating transmission of pressure pulsations.
摘要:
A photosensitive polyimide precursor composed of the structural units (A) represented by the following general formula (I) and the structural units (B) represented by the following general formula (II), in which the ratio of the molar quantity of the structural units (A) to the sum of the molar quantity of the structural units (A) and that of the structural units (B) is 0.01 or greater, and having a viscosity of 100 cP or above as measured at 25.degree. C. in the state of a 10% by weight solution in N-methylpyrrolidone: ##STR1## wherein R.sub.1 represents a tetravalent aromatic hydrocarbon residue; R.sub.2 represents a divalent aromatic hydrocarbon residue; X, identical or different represents a halogen or an alkyl group; and m represents 0 or an integer from 1 to 4. The photosensitivity of the present photosensitive polyimide precursor is about 20 to 100 times that of conventional products. After heat dehydration cyclization, it shows a heat resistance of 400.degree. C. or above.
摘要:
An object is to provide a process for producing the compound of formula 1 in higher yield by the ring-opening addition reaction of epoxytriazole with amine under mild conditions without using a large excess of 4-methylenepiperidine. The process for producing (2R,3R)-2-(2,4-difluorophenyl)-3-(4-methylenepiperidin-1-yl)-1-(1H-1,2,4-triazol-1-yl)butan-2-ol or an acid addition salt thereof comprises reacting (2R,3S)-2-(2,4-difluorophenyl)-3-methyl-2-[(1H-1,2,4-triazol-1-yl)methyl]oxirane with an acid addition salt of 4-methylenepiperidine in a reaction solvent in the presence of a hydroxide of an alkali metal or an alkaline earth metal selected from the group consisting of lithium, sodium, calcium, and strontium, or a hydrate thereof.
摘要:
[Problem]The present invention aims to provide a novel organometallic compound that can be used as a general-use highly active catalyst with superior selectivity for functional groups.[Means for Solving Problem]The present invention relates to an organometallic compound having a novel specific structure of general formula (1): and to a general-use highly active catalyst used in reductive amination reaction with superior selectivity for functional groups that comprises said organometallic compound, and to a process for preparing amine compounds by reductive amination reaction using said catalyst.