利用吉布斯吸附等温式探索求解电解质溶液活度的新方法

以吉布斯吸附等温式积分式为基础,数学推证表面势的表达式,并应用表面势的数学表达式探求了一种测算电解质溶液活度系数的新方法.选取KIM计算电解质溶液溶质的活度系数公式为新方法的活度系数经验关系式的具体表达形式,利用实验直接测得的不同浓度下的表面张力数据,采用最优化拟合的方法,求算出活度系数经验关系式中的待定系数,从而可以求得不同浓度下的电解质溶液中的溶质的活度系数和活度.计算结果与KIM文献值对比,活度系数曲线在不同的坐标尺度下有很好的一致性,这使得通过测定电解质溶液表面张力测算其活度成为可能.     

由含二元简单共晶的相图提取活度的新方法

由相图提取组元的活度及有关的热力学数据是获取体系的热力学性质的一种有效途径，近些年来提出了一些计算方法和公式[1－3]．对于简单共晶体系，最早的计算方法是凝固点下降法，此后也曾提出了熔化墙法[4]．为使计算更简明、实用，本文提出熔化吉布斯自由能法，在该计算式中组元的活度系数表示成体系组成的函数，可望能得到较广泛的应用．1公式推导因1为二元简单共品相图，为方便，组元A、B分别用1、2表示，在共晶点E左侧液相线CE上，组元1的摩尔熔化吉布斯自由能否C．1．T与其活度11．T之间有下列关系式：式中。且为组元1的摩尔分数，…     

Nd(NO_3)_3-HNO_3-H_2O体系的过量吉布斯自由能和Nd(NO_3)_3-HNO_3-H_2O-HDEHP-AMSCO体系水相中各组分活度系数的计算

我们简化了混合电解质溶液过量吉布斯自由能的Pitzer公式。用此简化公式并结合我们以往的工作计算了Nd(NO_3)_3-HNO_3-H_2O体系的过量吉布斯自由能和Nd(NO_3)_3-HNO_3-H_2O-HDEHP-AMSCO体系水相中各组分的活度系数,计算值与实验值均很接近。此工作为镧系金属萃取分离进行热力学分析提供了方便。     

电解质-非电解质混合溶液活度系数的关联及溶解度的推算-(NH~2)~2CO-NaCl-NH~4Cl-H~2O体系的液固平衡热力学

在浓电解质和非电解质溶液的各种热力学模型基础上,提出了三元,四元溶液活度系数的关联式和溶解度计算方法.只需要少量实验数据即可求出相互作用参数,用此法可以计算在某一未饱和组分浓度下的饱和组分浓度,计算结果和实验相符.     

热力学过剩函数与相图计算

一、引言热力学过剩函数的定义可以写成Y~E=Y~R-Y~I(1)式中Y~R和Y~I分别为实际溶液和同一组成假想为理想溶液的某热力学性质,可以是Gibbs自由能G、熵S、焓H和体积V等.这个定义也适用于溶液中各组元的偏摩尔热力学性质,容易证明,溶液中组元i的偏摩尔过剩函数与活度系数γ_i之间的关系如下,     

水溶液中氯化铯与糖(D-葡萄糖、D-果糖和蔗糖)相互作用的热力学参数研究(298.15K)

用钾离子选择性电极为测量电极,氯离子选择性电极为参比电极,设计组成无液接电池,用于氯化铯-糖(葡萄糖、果糖及蔗糖)-水三元体系中组分之间弱相互作用的热力学性质研究.通过测量电池的电动势获得氯化铯在糖水溶液中的活度系数,根据Scatchard理论推测出糖在氯化铯水溶液中的活度系数.通过Mcmillan-Mayer理论将体系的过量热力学函数与溶液中溶质的相互作用参数相关联,获得氯化铯与糖在水溶液中相互作用的吉布斯自由能参数及盐效应常数.运用结构相互作用模型、糖的羟基水化效应及色散能理论,探讨体系中溶质-溶质、溶质-溶剂间的相互作用及糖的立体结构和金属离子体积对热力学参数的影响.     

用于聚合物溶液扩散系数计算的活度系数模型比较

用40个聚合物溶液体系的实验数据,对三个有代表性的活度系数模型用于计算联系自扩散系数和互扩散系数的热力学因子的精度进行了比较,结果表明三个模型的精度相近,误差一般在20％左右。,因而本工作揭示了聚合物溶注保由自扩散系数计算与扩散系数的一个潜在问题。即由于活度系数模型计算热力学因子误差较大所带来的较大不确定性。     

计算离子液体溶液汽液相平衡的分子热力学模型

用平均球近似理论、微扰理论和UNIFAC基团贡献方法分别考虑离子之间的长程静电作用、离子与溶剂之间的中程静电作用以及所有粒子之间的短程作用,本文提出了一种新的分子热力学模型,可用于离子液体溶液中溶剂活度系数的计算.通过对含烷基咪唑磷酸酯类离子液体与水、甲醇或乙醇组成的9个二元体系的饱和蒸汽压数据进行关联,获得了相关的模型参数,即溶剂的分子直径和基团之间的交互作用能参数.溶剂活度系数及饱和蒸汽压的计算结果与实验值的平均偏差为1.40%,符合良好,因此本模型可望用于含离子液体体系汽液相平衡的预测.     

TmCl3-ACl（A=Na，K，Rb，Cs）体系相图的热力学优化计算

综合实验相图信息和热力学数据运用CALPHAD技术优化和计算了TmCl3-ACl体系的相图。液相的吉布斯全摩尔自由能采用新改进的用于短程有序体系的以近似似化学模型进行描述。借助计算机辅助分析，一系列的热力学函数被优化得到。计算的相图和热力学参数是热力学自恰一致的。     

乙烯在四氯化亚铜铝甲苯溶液中溶解度测定及其热力学模型

实测了乙烯在四氯化亚铜铝甲苯溶液中的溶解度。提出了一个处理伴有化学反应的气液平衡的热力学模型, 同时考虑了体系的相平衡和络合平衡, 将Scatchard-Hildebrand模型适当简化后, 计算其液相活度系数, 编制了计算程序, 模型应用方便。用该模型关联计算了溶解度实验数据, 结果令人满意。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。