共查询到16条相似文献,搜索用时 749 毫秒
1.
研究连串反应的动力学有十分重要的意义,文献[1,2]建立了两种连串一级反应的热动力学研究法.我们在前文[1]的基础上,建立了模拟热谱曲线法.该法可以直接从热导式量热计的热谱曲线上解析出连串一级反应中两步反应的速率常数.应用该法测定了邻苯二甲酸二乙酯和丁二酸... 相似文献
2.
本文综述了近年基于Tian方程建立的化学反应热动力学研究法的进展。重点评述了无量纲参教法、对比进度法、模拟热谱曲线法,特征参量法和时间变量法。 相似文献
3.
4.
5.
热动力学的研究 X. 一级反应的热谱峰高法 总被引:1,自引:0,他引:1
本文根据一级反应的热谱曲线方程、建立了速度常数的一种新算法。这种新方法,只需要热谱曲线在各个特征时刻的峰高,而不需要任何峰面积,即可算得反应体系的无量纲参数和速度常数,称为一级反应的热谱峰高法。 相似文献
6.
模拟热谱曲线法(Ⅰ)——简单级数化学反应 总被引:8,自引:1,他引:8
提出模拟各种简单级数化学反应的普适热谱曲线方程△=ate^-kβt,建立了一种新的热动力学研究法--模拟热谱曲线法,导出了简单级数化学反应的动力学参数Kn和速率常数kn的计算式。实验说明该方法对研究慢反应及较快的反应均适用,还能用于求热动力学体系的冷却常数。 相似文献
7.
模拟热谱曲线法(Ⅲ)——可逆反应 总被引:2,自引:2,他引:2
可逆反应是一类重要的复合反应,建立其相应的热动力学研究法有重要意义.刘劲松等[1]建立了可逆反应热动力学的对比进度研究法,曾宪诚等[2]建立了二种可逆反应热动力学无量纲参数研究法.本文根据热动力学理论和文献[3]的基本原理,建立了热导式量热体系的几类(2-2型、2-1型、1-2型)可逆反应通用的模拟热谱曲线研究法.该法无需标定热动力学体系的冷却常数,直接从一张热谱图上同时解析出可逆反应的kf、kb、K,方法更为简便,实用性强,在化学、生化反应的热动力学研究中具有广泛的应用前景.应用该法在15℃、25℃下研究了硝基乙烷… 相似文献
8.
9.
10.
11.
根据化学反应动力学和热动力学基本理论, 建立了简单级数反应的热动力学对比参量方程, 提出了一种新的热动力学研究法--对比参量法. 利用该法可以从一张热谱图上同时解析出化学反应的速率常数、半衰期和热动力学体系的冷却常数. 实验结果验证了方法的正确性. 相似文献
12.
Chen Y. Xie J. Q. Zhang B. Zeng X. C. 《Journal of Thermal Analysis and Calorimetry》2004,75(3):847-855
A novel thermokinetic research method for determination of rate constants of simple-order reaction in batch conduction calorimeter
under isothermal condition, the characteristic parameter method, is proposed in this paper. Only needing the characteristic
time parameter tm obtained from the measured thermoanalytical curve, the kinetic parameters of reactions studied can be calculated
conveniently with this method. The saponifications of ethyl propionate and ethyl acetate in aqueous ethanol solvent, the polymerization
of acrylamide in aqueous solution, the ring opening reaction of epichlorohydrin with hydrobromic acid have been studied. The
experimental results indicate that the characteristic parameter method for simple-order reaction is correct.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
14.
《Physics and Chemistry of Liquids》2012,50(1):34-46
Kinetic study of the reactions of amoxicillin (I), ampicillin (II) and cephlaxin (III) with p-dimethylaminobenzaldehyde (DAB) in weakly acidic EtOH/H2O solution has been investigated using spectrophotometric method. Relatively slow reversible reactions of first order with respect to the antibiotic have been found. A derived equation for detecting the existence of reversibility from the linearity has been introduced. The effect of anionic surfactants (sodium dodecyl sulfate, SDS) on the kinetic of these reactions in aqueous solution has been studied. The presence of 0.005 M of SDS increases the rate constants by 4.3, 2 and 3.3 times for I, II and III, respectively. The consequence of the rate constants have a similar order in absence and presence of SDS; III > II > I. The rate constants pass through maxima with increasing SDS concentration followed by a gradual but steady decrease in the rate as the surfactant concentration increases further. Multiple linear regression method has been performed to evaluate the binding constants of each drug and DAB with SDS from the resulted kinetic data. The results suggest using multiple linear correlation method for such calculations, which is more accurate, reliable and less time consuming. The calculated binding constants between these drugs with SDS are following the consequence I > II > III which is related to the differences in their substitutions. The kinetic results were employed for spectrophotometric microdetermination of these drugs (I–III) in aqueous solution. The method was based on the reaction of β-lactam with an excess of DAB in presence of SDS and HCl (pH 2) at a wavelength 410 nm. The results indicate that the presented method is simple, precise and accurate. This method is applied to bulk antibiotics and some of their pharmaceutical preparations. 相似文献
15.
16.
Characteristic parameter method for studying kinetics of opposing reactions in calorimeter 总被引:1,自引:0,他引:1
According to the theoretical basis of thermokinetics, the integral and differential thermokinetic equations of opposing reactions have been derived, and a novel thermokinetic research method, the characteristic parameter method for opposing reactions which taking place in a batch conduction calorimeter under isothermal condition, has been proposed in this paper. Only needing the characteristic thermoanalytical data corresponding to tm and 2tm from the same curve, the rate constants of forward and backward reactions and equilibrium constant can be calculated simultaneously with this method. In order to test the validity of this method, the proton-transfer reactions of nitroethane with ammonia at 15 and 25°C, and with trihydroxymethyl aminomethane (Tris) at 15 and 30°C have been studied, respectively. The results of rate constants and equilibrium constants calculated with this method are in agreement with those in the literature. Therefore, the characteristic parameter method for opposing reaction is believed to be correct.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献