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951.
介绍了日本学者对吡啶盐在造核感染显影体系中作用的研究。通过模拟肼效应快速显影体系的试验,证实了这些吡啶盐可以产生与酰肼类化合物相媲美的高反差特性,并讨论了产生高反差显影反应的可能机理。 相似文献
952.
As a series of experimental determinations of the thermal diffusivity of molten alkali halides, this paper describes measurements on five molten alkali metal chlorides (LiCl, NaCl, KCl, RbCl, and CsCl) in the temperature range up to 1440 K by the forced Rayleigh scattering method. K2Cr2O7 is employed as a dye substance to color the transparent molten salts. The accuracy is estimated to be ± 4 to ±11 % depending on the measured salts. In comparison with the present results converted into thermal conductivity, most of the previous experimental data obtained by steady-state methods show larger values, up to about five times, which may be due to the systematic error caused by the presence of convection and radiation. It is found that the thermal conductivity of these series of molten alkali metal chlorides decreases with increasing molecular weight, and their temperature coefficients are weakly negative. 相似文献
953.
Phase-transfer catalysts (PTC), which accelerate reactions between liquid(organic)-liquid(water) and liquidsolid heterogeneous states, have been investigated and developed. Several processes with PTC have succeeded in industrial processes involving fatty acids and their derivatives. For example, preparation of fatty alkyl glycidyl ethers, from which fatty alkyl glyceryl ethers and their derivatives can be obtained, has been carried out with PTC. However, some problems remain to be solved. For example, preparation of the fatty alkyl glycidyl ether by a PTC reaction was considered, but typical problems to be solved included: (i) how to reuse or recover the catalysts; (ii) how to control the heterogeneous reaction without obstacles to produce useful chemical materials; (iii) how to satisfy the environmental requirements for the catalysts; and (iv) are there more effective catalysts? We address these problems based on our own experiences with phase-transfer catalytic Williamson ether syntheses of fatty alkyl glycidyl ethers. Moreover, we describe recent developments in phase-transfer catalytic reactions related to oleochemistry, such as transition metal-catalyzed reactions of long-chain olefins in liquid(organic)-liquid(water) or liquid-solid heterogeneous states. Based on these results, we have considered the potential of PTC as a synthetic tool in oleochemistry. 相似文献
954.
含盐和甲醇体系中气体水合物的相平衡研究 Ⅰ.平衡生成条件的测定 总被引:3,自引:0,他引:3
在温度260.8~281.5K和压力0.78~11.18MPa下,采用“压力搜索法”在自行设计和组建的实验装置上测定了一个合成天然气在含盐以及含盐和甲醇水溶液体系中的水合物平衡生成条件,共11个体系72个数据点。结果表明,无论对于单盐或多盐水溶液体系,甲醇对天然气水合物的生成均有显著的抑制作用;当溶液中甲醇增加至20%(质量)时,KCl的抑制作用强于CaCl2。 相似文献
955.
Antonia P. de los Ríos Francisco J. Hernández‐Fernández Manuel Rubio Demetrio Gómez Gloria Víllora 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2007,82(2):190-195
Five different ionic liquids, based on dialkylimidazolium cations associated with perfluorinated and bis{(trifluoromethyl)sulfonyl}imide anions, were used to investigate the scope and limitations of these new solvents as media for penicillin G acylase‐catalyzed reactions. Deactivation of the native enzyme in ionic liquids (ILs) and in organic solvents (toluene, dichloromethane and 2‐propanol) at low water content and 40 °C was investigated using the hydrolysis of penicillin G as activity test. Native penicillin G acylase shows greater stability in IL media than in organic solvents. For example, a half‐life time of 23 h was obtained in 1‐ethyl‐3‐methylimidazolium bis{(trifluoromethyl)sulfonyl}imide, [emim+][Tf2N?], which was about 2000‐fold higher than that in 2‐propanol. An enhancement of the PGA stability was observed by the presence of substrate in ionic liquids based on tetrafluoroborate and hexafluorophosphate anions, achieving the highest increase of the half‐life time in 1‐butyl‐3‐methylimidazolium hexafluorophosphate ([bmim+][PF6?]), which was about 9‐fold higher than the half‐life time in the absence of substrate. Copyright © 2007 Society of Chemical Industry 相似文献
956.
The chemical reaction of trioctylamine (TOA) and sulfuric acid in organic solvent/aqueous solution was carried out. TOA salt products of various kinds were obtained based on different conditions of operation and organic solvents. An equilibrium model, based on the chemical reaction of sulfuric acid and trioctylamine, is proposed. The equilibrium constants of various reactions of trioctylamine and sulfuric acid were searched by means of the modified LETAGROP-DISTR computer program, from which the sum of the least-square error of the extraction of sulfuric acid per unit concentration of TOA salts was minimized. The corresponding concentration profiles of the various main products as a function of the activity of sulfuric acid in the aqueous solution were also obtained. The activity coefficient of the sulfuric acid in the aqueous phase and the density of the aqueous solution of sulfuric acid were considered in order to evaluate the activity of the sulfuric acid in the aqueous solution more accurately. The results obtained from the proposed model are consistent with that of Wilson's published model. 相似文献
957.
Jack Melling 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1994,59(1):1-1
The reactivity of trivalent chromium salts towards collagen, the main protein in animal skins, was investigated in organic solvents on lamb skins of controlled water content. The optimal conditions were determined by experiment modelling. Complete exhaustion of the tanning baths, and much higher chromium binding was observed with this system than with traditional processes carried out in aqueous media. 相似文献
958.
钴,镍萃取平衡数学模型及串级萃取过程最优化计算 总被引:1,自引:0,他引:1
本文把CoCl2-NiCl2-H2O-R3R’NCl萃取平衡体系的实验数据关联为数学模型,对萃取过程进行串级模拟和最优化计算,并在日处理0.9M^3料液的生产性试验中得到验证。计算得到的主要工艺参数,两相出口的主要指标,各组分浓度及分配比的逐级分布都与试验结果基本相符。 相似文献
959.
Two meat products, regular bologna and bologna-like beaker sausage, were used to test performance of low-fat bologna batters prepared with two chloride salts (NaCl or KCl) and two carrageenan types (kappa or lambda). In the beaker sausage, two carrageenan-salt combinations lowered cooking loss compared to controls, and lambda-carrageenan in the presence of potassium cations was most effective. In regular bologna, none of the carrageenan-salt combinations lowered the cooking loss usually resulting with large amounts of added water. Also, treatments with lambda-carrageenan were less firm than high-fat or low-fat controls. 相似文献
960.
Dongbin Zhao Zhaofu Fei Wee Han Ang Paul J. Dyson 《International journal of molecular sciences》2007,8(4):304-315
A series of sulfonium halides bearing allyl groups have been prepared and characterized. Anion metathesis with Li[Tf2N] and Ag[N(CN)2] resulted in sulfonium-based ionic liquids which exhibit low viscosities at room temperature. The solid state structure of one of the halide salts was determined by single crystal X-ray diffraction. 相似文献