摘要:
A method of producing a diol derivative efficiently and to high purity is provided. Specifically, the present invention relates to a method of producing a diol derivative having, as a fundamental step, a step of obtaining an α-hydroxycarboxylic acid ester by reacting (i) one or more 1,2-diols or (ii) a 1,2-diol and a primary alcohol as starting material(s) with oxygen in the presence of a catalyst comprising metal loaded on a carrier.
摘要:
The present invention provides a process for more efficiently producing an α-hydroxycarboxylic acid ester wherein side reactions due to the α-hydroxycarboxylic acid ester are inhibited or prevented in comparison with prior art production processes. The invention provides a process for producing an α-hydroxycarboxylic acid ester comprising Steps 1 to 3: Step 1. reacting, in the presence of oxygen, (i) a 1,2-diol with a 1,2-diol or (ii) a 1,2-diol with an alcohol to obtain a reaction product containing an α-hydroxycarboxylic acid ester; Step 2. separating the α-hydroxycarboxylic acid ester from the reaction product obtained in Step 1 by distillation under reduced pressure; and Step 3. feeding Step 1 with a mixture obtained by partially or entirely removing water from the reaction product, wherein the mixture contains an unreacted 1,2-diol and/or alcohol.
摘要:
A low temperature-fired porcelain article includes a barium component in an amount of 40 to 65 wt % when calculated as BaO, a silicon component in an amount of 25 to 46 wt % when calculated as SiO2, an aluminum component in an amount of 0.1 to 20 wt % when calculated as Al2O3, a boron component in an amount of 0.3 to 1.5 wt % when calculated as B2O3, and a zinc component in an amount of 0.5 to 20 wt % when calculated as ZnO, optionally also a chromium component in an amount of 0.5 to 3.5 wt % when calculated as Cr2O3 wherein the porcelain article has a dielectric constant ∈r of not more than 10, a quality coefficient Q of not less than 2500, and preferably has an absolute value of a temperature coefficient &tgr;f of the resonance frequency of not more than 30 ppm/° C.
摘要翻译:作为低温烧成瓷制品,按照BaO计算,其含量为40〜65重量%的钡成分,SiO 2计算为25〜46重量%的硅成分,0.1成分的铝成分 至20重量%,当以B 2 O 3计算时,硼成分为0.3〜1.5重量%,锌成分为0.5〜20重量%,以ZnO计,也可为铬成分 以Cr 2 O 3计,其中瓷制品的介电常数εr不大于10,品质系数Q不小于2500,优选具有绝对温度系数tgr的量为0.5-3.5重量%。 f的共振频率不大于30ppm /℃
摘要:
The biosensor of this invention can quantify a substrate in a sample liquid by electrochemically measuring the amount of an electron acceptor that has been reduced by electrons generated in a reaction between the substrate and an oxidoreductase. The biosensor has an electrically insulating substrate and an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction. The third electrode can be used merely for detecting a liquid junction, or can be used as both a reference electrode and a liquid junction detecting electrode.
摘要:
A RE-Ba-Cu-O type oxide superconducting material (RE represents Y, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb, Lu or a combination of two or more of them) having a phase structure including a REBa.sub.2 Cu.sub.3 O.sub.y phase and a RE.sub.2 BaCuO.sub.5 phase of 20 .mu.m or less in diameter dispersed in the REBa.sub.2 Cu.sub.3 O.sub.y phase, in which superconducting material RE consists of at least two elements selected from Y, Cl, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu. Said oxide superconducting material can be produced by melt processing.
摘要:
The present invention provides a process for more efficiently producing an α-hydroxycarboxylic acid ester wherein side reactions due to the α-hydroxycarboxylic acid ester are inhibited or prevented in comparison with prior art production processes.The invention provides a process for producing an α-hydroxycarboxylic acid ester comprising Steps 1 to 3:Step 1. reacting, in the presence of oxygen, (i) a 1,2-diol with a 1,2-diol or (ii) a 1,2-diol with an alcohol to obtain a reaction product containing an α-hydroxycarboxylic acid ester;Step 2. separating the α-hydroxycarboxylic acid ester from the reaction product obtained in Step 1 by distillation under reduced pressure; andStep 3. feeding Step 1 with a mixture obtained by partially or entirely removing water from the reaction product, wherein the mixture contains an unreacted 1,2-diol and/or alcohol.
摘要:
The present invention provides a high performance glucose sensor which can demonstrate high stability against preservation and produces only a low blank value. The glucose sensor comprises an electrically insulating base plate, an electrode system formed on the base plate, and a reaction layer which is formed in contact with or in the vicinity of the electrode system and contains at least a glucose dehydrogenase whose coenzyme is pyrrolo-quinoline quinone, the reaction layer further containing an additive such as phthalic acid.
摘要:
A method of producing a diol derivative efficiently and to high purity is provided. Specifically, the present invention relates to a method of producing a diol derivative having, as a fundamental step, a step of obtaining an α-hydroxycarboxylic acid ester by reacting (i) one or more 1,2-diols or (ii) a 1,2-diol and a primary alcohol as starting material(s) with oxygen in the presence of a catalyst comprising metal loaded on a carrier, further hydrolyzing the α-hydroxycarboxylic acid ester to obtain α-hydroxycarboxylic acid, and subjecting the α-hydroxycarboxylic acid to polycondensation.
摘要:
A method for purifying glyoxylates includes (1) a coarse distillation process in which a crude glyoxylate in which water coexists is, in a film form, continuously subjected to coarse distillation, and (2) an azeotropic dehydration process in which the crude glyoxylate purified through the coarse distillation process is subjected to azeotropic dehydration in the presence of an azeotropic agent such as propyl acetate. By this method, high-purity glyoxylates can be efficiently and easily obtained at lower costs.
摘要:
The biosensor of this invention can quantify a substrate in a sample liquid by electrochemically measuring the amount of an electron acceptor that has been reduced by electrons generated in a reaction between the substrate and an oxidoreductase. The biosensor has an electrically insulating substrate and an electrode system formed on the substrate including a working electrode, a counter electrode and a third electrode used for detecting a liquid junction. The third electrode can be used merely for detecting a liquid junction, or can be used as both a reference electrode and a liquid junction detecting electrode.