An experimental investigation of the cross-flow of power law liquids past a bundle of cylinders and in a bed of stacked screens
作者:D. V. N. Prasad、R. P. Chhabra
DOI:10.1002/cjce.5450790106
日期:2001.2
pour une serie de solution aqueuses de carboxymethyle cellulose et d'alginate desodium inelastiques. Les valeurs de facteurs de friction obtenues montrent une bonne correlation avec une definition modifiee du nombre de Reynolds reposant sur la representation en faisceaux capillaires du lit. Lesnouvelles donnees etendent considerablement la gamme des valeurs de vide de ∼0, 6 a ∼0, 87. Des comparaisons
已通过实验研究了垂直于圆柱阵列和筛床中的幂律聚合物溶液的稳定流动。对一系列非弹性羧甲基纤维素和海藻酸钠水溶液的不同空隙率的三个不同测试池(两个管束和一个由筛网制成的床)进行了广泛的压降测量。摩擦系数的结果值与基于床的毛细管束表示的雷诺数的修改定义很好地相关。新数据大大扩展了空隙率值的范围,从~0.6 到~0.87。在目前的实验数据和我们之前基于使用简单细胞模型的计算之间也进行了广泛的比较。两者之间的密切对应证明了这种理想化分析的实用性。总而言之,目前的结果包含以下物理和运动学条件范围:雷诺数:0.01 至 ∼1200;幂律流动行为指数:0.38比1;和三个空隙率值,即0.74、0.78和0.87。在 a etudie de facon experimentale l'ecoulement en 制度永久 perpendiculairement 一个 des 安排 de cylindres et
Direct Access to Acylated Azobenzenes and Amide Compounds by Reaction of Azoarenes with Benzylic Ethers as Acyl Equivalents
pathway for the Pd-catalyzed regiospecific ortho-acylation of azoarenes using benzylic ethers as acyl equivalents has been achieved. In the absence of palladium catalyst, amide compounds were formed by the reaction of azoarenes with benzylic ethers under certain conditions. Various mono-acylazobenzene and amide compounds were obtained in good yields (35 examples). The mono-acylated products and amide
Preparation of a platinum nanoparticle catalyst located near photocatalyst titanium oxide and its catalytic activity to convert benzyl alcohols to the corresponding ethers
nanoparticle catalyst closely located near the surface of titanium oxide, PtNP/TiO2, has been prepared. This catalyst has both the properties of a photocatalyst and a metal nanoparticle catalyst, and acquired environmentally friendly catalytic activity, which cannot be achieved by just one of these catalysts, to afford ethers from benzyl alcohols under the wavelength of 420 nm.
Dehydration of Benzyl Alcohols in Phosphonium Ionic Liquids: Synthesis of Ethers and Alkenes
作者:Hassan A. Kalviri、Francesca M. Kerton
DOI:10.1002/adsc.201100445
日期:2011.11
The dehydration of benzylic alcohols has been studied in several phosphonium ionic liquids in the absence of any metal catalysts. Benzyl ethers and alkenes were obtained from primary and secondary benzylic alcohols in good to excellent yields for these reactions. Commercially available hydrophobic phosphonium ionic liquids containing the trihexyl(tetradecyl)phosphonium cation paired with six different
Synthesis of Ethers from Carbonyl Compounds by Reductive Etherification Catalyzed by Iron(III) and Silyl Chloride
作者:Reko Leino、Risto Savela
DOI:10.1055/s-0034-1380155
日期:——
with ethyl acetate as the solvent. A simple iron- and silylchloridecatalyzed method for the preparation of symmetrical and nonsymmetrical ethers is presented. Various aldehydes and ketones were reductively etherified by using triethylsilane as a reducing agent in the presence of 2 mol% of iron(III) oxo acetate and 8 mol% of chloro(trimethyl)silane. The reactions can be carried out at ambient temperatures