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Low-temperature heat capacities of crystalline Ho(Gly)_(3)Cl_(3)·3H_(2)O from 78 to 348 K
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作者 张景楠 王辉 +3 位作者 谭志诚 刘北平 史全 童波 《Journal of Rare Earths》 SCIE EI CAS CSCD 2009年第6期919-922,共4页
Heat capacities of the rare-earth complex with glycine [Ho(Gly)3Cl3·3H2O] were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 348 K.In the experimental temper... Heat capacities of the rare-earth complex with glycine [Ho(Gly)3Cl3·3H2O] were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 78 to 348 K.In the experimental temperature range,the heat capacities increased in a smooth and continuous manner and no phase transition or thermal anomaly occurred.Therefore,the sample was stable in the above temperature range.The values of experimental heat capacities were fitted to a polynomial equation with least square method and the thermodynamic functions,(HT-H298.15) and(ST-S298.15),were calculated. 展开更多
关键词 rare-earth complex Ho(Gly)3Cl3·3H2O low-temperature heat capacities thermodynamic functions
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Density estimated physicochemical properties of alanine-based ionic liquid [C_7mim][Ala] and its application in selective transesterification of soybean oil 被引量:2
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作者 FANG DaWei LI Meng +3 位作者 GE RiLe ZANG ShuLiang YANG JiaZhen GAO YanAn 《Science China Chemistry》 SCIE EI CAS 2012年第8期1677-1682,共6页
Amino acid ionic liquid (AAIL) based on alanine, 1-n-heptyl-3-methylimidazolium alanine ([C7mim][Ala]), has been prepared and characterized. Since the IL can form strong hydrogen bonds with water, trace amount of wate... Amino acid ionic liquid (AAIL) based on alanine, 1-n-heptyl-3-methylimidazolium alanine ([C7mim][Ala]), has been prepared and characterized. Since the IL can form strong hydrogen bonds with water, trace amount of water is a problematic impurity in the IL. Using the standard addition method (SAM), the densities were measured in the temperature range from 293.15 to 343.15±0.05 K. On the basis of the experimental data of density, the surface tension , molar volume, and the molecular volume Vm, molar enthalpy of vaporization lgHm0, and the thermal expansion coefficients , for [C7mim][Ala] were estimated using semi-empirical methods. Also the interstice model has been verified with good accordance. Then the [C7mim][Ala] was taken as catalyst in the transesterification reaction with fatty acid, where soybean oil was used as raw material and methanol as reactant. The amount of catalyst, alcohol consumption, reaction time, temperature and other factors of the reaction were investigated. Using GC determination, the conversions were calculated by the internal standard method. The main ingredients of the products were identified by GC-MS as palm methyl ester and linoleic acid methyl ester only, which showed high selectivity in palmitic acid and linoleic acid. 展开更多
关键词 酯交换反应 密度估计 离子液体 丙氨酸 物理化学性质 大豆油 亚油酸甲酯 棕榈酸甲酯
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