交流电解阻抗的数字模拟——Ⅰ.可逆、准可逆体系和薄层电解池的电解阻抗

本文用数字模拟方法研究了可逆、准可逆和不可逆电极反应的交流阻抗,得到了与理论推导相符合的结果。文中亦研究了薄层电解池的交流阻抗的数字模拟。通过数字模拟,人们不需用等效电路模型便能解释交流阻抗数据的化学意义,这对认识复杂电极过程尤为重要。文中给出了交流阻抗的离散数字模型,并讨论了动力学参数对阻抗数据的影响。     

耦联一级随后化学反应的准可逆表面体系循环伏安法数字模拟研究

用数字模拟方法研究了耦联一级不可逆随后化学反应的可逆、准可逆及不可逆表面吸附体系的循环伏安响应.建立了有关数字模型.模拟计算得到不同无量纲动力学参数时电流函数-电位极化曲线.给出了测定电荷传递速率常数k和随后反应速率常数中k₁的方法.并研究了对甲氧基偶氮苯在酸性介质中的伏安响应,结果尚好.     

脉冲极谱法研究(Ⅰ)——受吸附影响的常规脉冲极谱可逆波方程

本文提出了同时受反应物和产物吸附影响的常规脉冲极谱可逆波方程式,并对电流和电位的性质进行了讨论。所得结果与数字模拟法计算得到的曲线完全相符。     

可逆型化学振荡器

该文给出了可逆型化学振荡器的定义、意义和可能存在的类型。这些类型包括：（1）自发乳化，通电破乳；（2）乳液中自发产生的甘油三酯水解振荡反应及通电逆向酯化反应；（3）用表面活性剂有机溶液代替盐桥，形成新型的电化学振荡，通电逆向电解。文章对这3种类型可逆型化学振荡器的来源、组成、实验方法、理论分析方法和应用前景进行了深入的讨论和分析。它们还可以进一步组合，形成更多的类型。其主要的研究方法为用正交实验确定最佳配方，由相关分析确定影响因素。这些可逆型化学振荡器的关键组分都是表面活性剂，是表面活性剂在非线性化学动力学研究中的又一应用。对可逆型化学振荡器的研究必将大大促进远离平衡态的复杂反应动力学研究及新型交流蓄电池的开发设计。     

Daniell电池的电池反应可逆吗?

现行大多数物化教材,都将Daniell电池 (一) Zn|ZnSO_4(aq)(?)CuSO_4(aq)|Cu(+)作为典型的可逆电池描述,认为其放、充电反应是可逆的。而笔者认为该电池应是不可逆的,因其除有液接面“(?)”外,更主要的是微量电流通过时放、充电反应是不可逆的。按可逆电池的条件,通过整个回路的电流必须是无限小量或微量的,以保证各种电化学过     

可逆加成-断裂链转移聚合研究进展

对可逆加成．断裂链转移(RAFT)聚合的反应机理、可逆加成．断裂链转移荆的合成方法及其反应动力学的研究进展分别进行了综述。     

超微盘、微半球电极上准稳态电流公式及其实验验证

经过严格的数学推导及合理的数学近似, 提出了超微盘及微半球电极上准稳态可逆波、准可逆波及不可逆波电流方程式。根据导出的准稳态电流方程, 提出了一个测定动力学参数的新方法。对理论公式也进行了实验验证。     

可逆体系中园盘微电极循环伏安法理论研究

用新的处理方法提出可逆体系微盘电极准稳态及快速循环伏安理论电流公式,新方程表示了微盘电极电流可分解成平面扩散与球面扩散传质两项之和,微盘电极上的电流特征取决于各种参数的改变。例如τ（）和ｖ。本文对微电极循环伏安法出现稳态、准稳态曲线及形成“滞后环”等原因及条件均从理论上作出解释,并进行了定量计算;文中对微电极快速循环伏安理论也有详细讨论。     

耦联酶催化反应电化学体系的表面循环伏安行为的数字模拟

采用数字模拟法对耦联酶催化反应体系的表面循环伏安行为进行了研究,讨论了介体氧化还原动力学、酶催化动力学及介体催化酶动力学等参数对循环伏安图的影响,并用实验进行了验证。     

常规二脉冲叠加四阶跃微分伏安法研究：—可逆电极过程的理论和验证

推导并验证了提出的新型阶跃伏安技术－常规二脉冲叠加四阶跃微分伏安法可逆电极过程听理论电流方程，同时研究了各项参数如扫描增量（Es)、脉冲高度（△E）、脉冲周期（T）等对实验的影响，理论与实验结果一致。     

Non-equilibrium thermodynamics and kinetic theory of gas mixtures in the presence of interfaces

A broad range of the boundary value problems of the kinetic theory of gases and gas mixtures is considered based on kinetic theory and non-equilibrium thermodynamics. The interrelation of the kinetic theory and non-equilibrium thermodynamics is discussed. The balance equations at the interface are obtained for the case of the boundary layers with peculiar properties. Procedures for deriving the boundary conditions for slightly rarefied gas mixtures are outlined. The problems of calculating slip coefficients are discussed. The specificity of the kinetic effects in the boundary conditions is shown. A set of general relations related to gas mixture flows in capillaries is deduced. The possibility of non-equilibrium kinetic effects in the form of a paradoxical distribution of non-equilibrium temperature is shown. Methods of non-equilibrium thermodynamics are used to obtain the phenomenological equations describing the thermophoresis and diffusiophoresis of particles and cross phenomena. The growth and evaporation of droplets is considered based on kinetic theory and non-equilibrium thermodynamics.     

Comparison of thermokinetic data obtained by isothermal, isoperibolic, adiabatic and temperature programmed measurements

In this paper isothermal, isoperibolic and adiabatic calorimeters and a Power-Compensating DSC are compared by determining kinetic data of a simple test reaction. First, the kinetic parameters were analyzed using a conventional isothermal method, based on the analytic determination of the course of reaction. Subsequently, the kinetic data of the performed reaction were determined for the different types of calorimeters by simultaneously evaluating several measurements with identical initial conditions but different temperature courses. The kinetic parameters obtained by the different calorimeters agree reasonable well, indicating the reliability of kinetic data derived from thermokinetic methods.The authors are thankful for the financial support by the Department of Education and Research of the Federal Republic of Germany (BMBF).     

Kinetic Methods of Analysis: How Do They Rate?

During the past few years there has been a resurgence of interest in kinetic aspects of analytical chemistry and in kinetic methods of analysis. The increased activity is a result of advances that have been made in instrumentation and in data processing techniques. Still, the kinetic approach is not widely applied by practicing analytical chemists. Why is this true? Why are kinetic methods not among the most common methods in use by analytical chemistry? This paper discusses the advantages and limitations of kinetic methods and addresses the probable reasons that they are not widely used. Several new principles have cmerged that are guiding the development of new kinetic-based determinations. These developments have made it possible to compensate for errors that result from changes in reaction conditions and to determine accurately multiple components in mixtures. With these advances kinetic methods are approaching the reliability of traditional equilibrium-based determinations and should be re-evaluated by analytical chemists.     

Ozawa’s kinetic method for analyzing thermoanalytical curves

By reviewing the history of thermal analysis and its application to the kinetic analysis of the solid-state processes, we investigate the theoretical basis and historical perspective of Ozawa’s kinetic method for analyzing thermoanalytical curves. Ozawa’s nonisothermal kinetic method is demonstrated using thermoanalytical data for the thermal decomposition of sodium hydrogencarbonate and the crystallization of anhydrous magnesium acetate glass as examples. Through investigating recent theoretical advancements in nonisothermal kinetic analysis in view of the theoretical fundamentals of Ozawa’s kinetic method, it is indicated that they are in line with Ozawa’s kinetic theory. On the basis of the above investigations, we discuss the role of Ozawa’s kinetic theory in advancing the analysis of complex reaction kinetics.     

Multicomponent kinetic determinations using multivariate calibration techniques

Multivariate calibration techniques for use in multicomponent kinetic-based determinations are reviewed. Multivariate calibration is a chemometric tool that continues to grow in popularity among analytical chemists. Multicomponent kinetic methods depend on differences in rates of reactions or processes to distinguish among the components. Kinetic profiles or a combination of kinetic profiles and spectra are commonly used. Because of their ability to process large quantities of data, multivariate calibration techniques are well suited for kinetic-based determinations. The concepts and principles of multivariate calibration are discussed first. Classical least squares regression, principal component regression, partial least squares regression and artificial neural networks are the multivariate calibration techniques considered here in detail. Recent examples of the application of these techniques to multicomponent kinetic determinations are reviewed. Both single and multiwavelength kinetic data are considered.     

On the single-electron local kinetic energy

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Kinetic energy density study of some representative semilocal kinetic energy functionals

There is a number of explicit kinetic energy density functionals for noninteracting electron systems that are obtained in terms of the electron density and its derivatives. These semilocal functionals have been widely used in the literature. In this work, we present a comparative study of the kinetic energy density of these semilocal functionals, stressing the importance of the local behavior to assess the quality of the functionals. We propose a quality factor that measures the local differences between the usual orbital-based kinetic energy density distributions and the approximated ones, allowing us to ensure if the good results obtained for the total kinetic energies with these semilocal functionals are due to their correct local performance or to error cancellations. We have also included contributions coming from the Laplacian of the electron density to work with an infinite set of kinetic energy densities. For all but one of the functionals, we have found that their success in the evaluation of the total kinetic energy is due to global error cancellations, whereas the local behavior of their kinetic energy density becomes worse than that corresponding to the Thomas-Fermi functional.     

KDP晶体台阶生长动力学的激光干涉实验研究

采用迈克尔逊干涉技术,通过测量KDP晶体生长的法向速率和台阶斜率来研究其台阶生长的动力学系数、台阶自由能、溶质在边界层内的扩散特征以及激发晶体生长台阶的位错活性.实验表明, KDP中不同活性位错的台阶动力学系数差异较大,例如高活性和低活性台阶动力学系数分别为10.3×10-2和5.21×10-2 cm/s,位错源在晶体表面的形状、面积的变化,以及Burgers矢量的变化是造成晶体生长动力学测量数据重复性差的主要原因.     

Kinetic approach to partially overlapped thermal decomposition processes

Practical usefulness of the kinetic deconvolution for partially overlapped thermal decomposition processes of solids was examined by applying to the co-precipitated basic zinc carbonate and zinc carbonate. Comparing with the experimental deconvolutions by thermoanalytical techniques and mathematical deconvolutions using different statistical fitting functions, performance of the kinetic deconvolution based on an accumulative kinetic equation for the independent processes overlapped partially was evaluated in views of the peak deconvolution and kinetic evaluation. Two-independent kinetic processes of thermal decompositions of basic zinc carbonate and zinc carbonate were successfully deconvoluted by means of the thermoanalytical measurements in flowing CO₂ and by applying sample controlled thermal analysis (SCTA). The deconvolutions by the mathematical curve fittings using different fitting functions and subsequent formal kinetic analysis provide acceptable values of the mass-loss fractions and apparent activation energies of the respective reaction processes, but the estimated kinetic model function changes depending on the fitting functions employed for the peak deconvolution. The mass-loss fractions and apparent kinetic parameters of the respective reaction processes can be optimized simultaneously by the kinetic deconvolution based on the kinetic equation through nonlinear least square analysis, where all the parameters indicated acceptable correspondences to those estimated through the experimental and mathematical deconvolutions. As long as the reaction processes overlapped are independent kinetically, the simple and rapid procedure of kinetic deconvolution is useful as a tool for characterizing the partially overlapped kinetic processes of the thermal decomposition of solids.     

Synthesis of hydrated furans: Analysis of the Prins reaction mechanism

Mechanistic analysis of hydrogenated furan synthesis by the Prins reaction was carried out using mathematical modeling. The direct and inverse chemical kinetic problems are solved for the rate constants of all elementary steps. A probable mechanism is derived from the obtained quantitative kinetic parameters and the kinetic patterns of the reaction. These include kinetic curves from the concentration changes of all species in the reaction.