摘要:
An actuator of the present invention is composed of a monomorph-type piezoelectric ceramic. The monomorph-type piezoelectric ceramic is a BaTiO.sub.3 -based ceramic, a PZT based ceramic having Nb, Sb, La, Mn, Nd and Bi, BaTiO.sub.3 --SrTiO.sub.3 -based ceramic containing SrTiO.sub.3 by 20 to 35 mole %, K(Nb, Ta)O.sub.3 -based ceramic, or a ceramic represented by a general formula: [Pb, (A.sub.1/2 B.sub.1/2)](Zr.sub.1-n, Cn)O.sub.3 where A is a monovalent element such as Li, Na, K, Rb, Cs or the like, B is a trivalent element such as Bi, La, Y, Sb, Ga or the like, A and B being both replaceable solid-meltable elements for Pb, C is an element such as Ti, Sn or the like that is a replaceable solid-meltable element for Zr, and n is from 0 to 0.8.
摘要:
A high .alpha.-type silicon nitride powder is prepared by thermally decomposing a mixture of a crystalline silicon nitride powder having an oxygen content of at least 1.0% by weight and a nitrogen-containing silane compound.
摘要:
A silicon nitride powder having an enhanced sintering activity is prepared by heating a mixture of a nitrogen-containing silane compound and a sintering aid in a non-oxidizing atmosphere.
摘要:
High-purity .alpha.-type silicon nitride comprised of a granular crystal having an .alpha.-phase content of at least 95%, a nitrogen content of at least 38% by weight and an average particle size of not larger than 3 .mu.m is provided. This high-purity .alpha.-type silicon nitride is prepared by heating a nitrogen-containing silane compound at a temperature of at least about 1,300.degree. C. in a heating furnace comprised of a material containing a metal having a melting point exceeding 1,600.degree. C. and capable of being bonded with oxygen at the heating temperature.
摘要:
A method of manufacturing highly purified silicon nitride including the steps of preparing a nitrogen-containing silane selected from the group consisting of tetra-amide-monosilane and silicon imide, and heat-treating the prepared nitrogen-containing silane in the presence of ammonia in an inner atmosphere at a temperature above 400.degree. C. for a period of at least two hours to obtain silicon nitride, and cooling and collecting the silicon nitride thus formed. The step of preparing the nitrogen-containing silane comprises continuously reacting gaseous silicon tetra-chloride with gaseous ammonia in an inner atmosphere at a temperature of from -30.degree. to 70.degree. C. to produce the nitrogen-containing silane as a product and collecting the product. The resultant silicon nitride so produced has a chlorine content of less than 0.05 weight percent and a nitrogen content of over 38 weight percent.
摘要:
The organic polymer particles comprise a carboxyl group and 2,3-dihydroxypropyl group, and the magnetic particles for diagnostics comprise fine magnetic material particles and a polymer part containing a hydrophilic polymer part and a crosslinked polymer part, a dry coating film obtained from a water dispersion thereof having a contact angle with water of 5° to 60°. The process for producing the carboxyl group-containing particles comprises a step of producing an ester bond by reacting a hydroxyl group in organic polymer particles having the hydroxyl group with a carboxylic anhydride. The organic polymer particles comprise a hydroxyl group originating from a 2,3-dihydroxypropyl group and a polyoxyethylene group.
摘要:
The present invention relates to a crystalline polymorph of 2-[4-[2-[[(1S,2R)-2-hydroxy-2-(4-hydroxy-phenyl)-1-methylethyl]amino]ethyl]phenoxy]acetic acid having strong diffraction peaks (diffraction angle: 2&thgr;±0.1°) at 10.8, 19.1, 19.3, 19.8, 20.6 and 27.0° in powder X-ray diffraction pattern, which has potent &bgr;2- and &bgr;3-adrenoceptor stimulating effects and is useful as an agent for relieving pain and promoting the removal of calculi in urolithiasis, and the like. For example, the crystalline polymorph can be prepared by hydrolyzing ethyl 2-[4-[2-[[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]-amino]ethyl]phenoxy]acetate phosphate by sodium hydroxide, adding an aqueous phosphoric acid solution at 40° C. and over, adding a mixed solvent of water and methanol or methanol to the resulting compound, and stirring the suspension at 40° C. to reflux temperature for 30 minutes to several hours.
摘要:
A process for preparing large-sized polymer particles having a particle diameter in a range of 0.1 to 500 .mu.m by seeded polymerization is described, comprising:finely dispersing a polymerizable monomer in an aqueous medium to prepare a monomer dispersion in which a number average particle diameter of the resulting monomer droplets is not larger than that of seed particles, and a number average particle diameter in a semi-stable condition (Dm) of the monomer droplets satisfies, with a desired number average particle diameter of the final polymer particle as D, the following relation:0.5.times.D
摘要:
The present invention provides an industrial method for preparing aminoalcohol derivatives (I) having a biphenyl group, biphenyloxyacetaldehyde derivatives which are used therefore, preparing methods thereof, and intermediates used for the preparing method.The present invention also provides a preparing method including processes for preparing a 3-substituted biphenylcarboxylic acid derivative represented by the following general formula: by allowing a 3-fluorobiphenylcarboxylic acid derivative prepared from a 3-fluorobiphenylcarbonitrile derivative which can be prepared by allowing a 4-halophenol derivative to react with a 2-fluorobenzonitrile derivative which is substituted by a leaving group at 4-position to react with an organometallic reagent.
摘要:
The present invention provides ethyl (−)-2-[4-[2-[[(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino]ethyl]-2,5-dimethylphenoxy]acetate hydrochloride, crystalline forms thereof and pharmaceutical compositions containing them, which have excellent β3-adrenoceptor stimulating effects, therapeutic effects on pollakiuria or urinary incontinence and storage stabilities and are useful as a medicament.