流加式聚合反应生产过程的动态模型及其参数估计

流加式聚合反应生产过程相当复杂,其模型化同时涉及聚合反应动力学、传热、相变原理以及热量、质量动态平衡定律等。本文为一类流加式聚合反应生产过程建立了动态数学模型,并基于某化工厂聚醚釜的实际运行数据估计了其中的各种参数。从而为开发此类过程的控制和优化方案提供了基础。     

PARAMETER ESTIMATION IN CAKE WASHING

The uniform-film model for cake washing considers the cake to be composed of channels in which a stagnant film of solute-rich filtrate adheres to the surface of the channel.

Two independent methods are presented for an unbiased evaluation of the uniform-film model parameters. The first is an iterative procedure which requires adjustment of only one model parameter, and the second is a direct analytical procedure based on the method of moments. Both require experimental data to identify the model parameters.

Application of the two methods give wet-base porosities greater than unity which suggests that the experimental data used to determine the model parameters is beyond the domain of applicability of the uniform-film model.     

强制浓度振荡下的反应动力学参数特征函数估计法

研究了特征函数法(Karhunen-Lo(?)ve方法)在降低常微分方程组维数方面的可能性,并以CO氧化反应系统为例,说明该法的应用步骤.模拟结果证实了此方法的有效性.     

PARAMETER ESTIMATION FOR PERIODIC ARMA MODELS

Abstract. In time series analysis of data sequences, the estimation of the parameters of an identified autoregressive moving-average (ARMA) model is a well-known and straightforward exercise. However, if the parameters of the model are periodic (i.e. a periodic ARMA (PARMA) model) then the estimation process becomes more difficult. This paper describes an on-line parameter estimation technique, based on methods from automatic control, which is demonstrated to provide consistent estimates of PARMA model parameters.     

A JOINT EXPERIMENTAL DESIGN PROCEDURE FOR PARAMETER ESTIMATION

A joint experimental design procedure which aims at obtaining precise parameter estimates of a given mathematical model is proposed and illustrated by means of computer simulated experiments

This criterion is found both to modify the shape of the joint confidence hyperellipsoid and to reduce its volume significantly

Therefore, it behaves as a combination of two of the most representative techniques in use today, known as the minimum volume or the shape criteria. Numerical results are given which serve to display its salient features and to compare it with the above mentioned techniques.     

试差矩阵熬及其在复杂反应动力学研究中的应用

本文提出了一种研究高维拟一级复杂反应动力学的新方法——试差矩阵法.该方法充分运用有效的数学方法和计算技术,以减少实验工作量,并能大大减少待定参数个数,提高估值精度.研究表明,该方法具有良好的方法统计特性,能耐受较大的实验误差。本文还提出了新的八碳芳烃临氢异构化和六碳组份重整体系的反应网络,应用试差矩阵法成功地研究了这两个体系的双曲型动力学模型,求取了各模型参数,模型拟合值与实验值能很好地吻合.     

OPTIMAL DESIGN OF A CLOSED LOOP CONTROLLER FOR ESTIMATION OF PARAMETER COUPLES OF MICROBIAL GROWTH KINETICS

This paper deals with the design of a feedback controller for the decorrelated estimation of a parameter couple appearing in an unstructured model for growth of one biomass on one limiting substrate in a fed-batch bioreactor. By optimal experimental design, feed rate strategies for decorrelated parameter estimation have been constructed (as reported elsewhere). These profiles have in common a feeding phase in which the substrate concentration is kept constant at a setpoint value by a feedforward controller. On simulation level this controller can be applied as an open loop controller. However, in practice these feed rate strategies are to be implemented in closed loop. Since during experimental design on simulation level a nominal parameter set is required, an iterative approach is needed to end up with a truly optimal experiment for estimation of the unknown parameters. Such an iterative scheme is proposed and its convergence properties are discussed     

MgO-SiC复合材料烧结初期动力学研究

研究了MgO -SiC复合材料烧结初期的动力学关系 ,结果表明材料的烧结机理服从体积扩散过程。探讨了SiC的加入对MgO材料烧结的影响 ,求出了复合材料的烧结活化能。     

低温液相甲醇合成反应动力学模型与参数估计

由低温液相甲醇合成的反应机理出发 ,考虑了均相和多相催化剂的不同作用及不同的吸附方式 ,导出了两步法低温液相甲醇合成的动力学模型 .结合搅拌釜中测得的动力学数据 ,对动力学模型进行了筛选和参数回归 .结果表明氢气为分子吸附 ,反应为双位吸附反应 ,甲醇脱附为反应控制步骤的反应动力学模型能较好地拟合实验数据 .由此得到了低温液相甲醇合成反应动力学模型方程 ,模型满足F检验 ,且参数符合各自的物理意义 .该动力学模型由于是对两步反应综合起来进行动力学分析 ,因而结果可在反应器数学模型中应用     

非线性分布参数系统状态估计的最佳测量位置

研究了分布参数系统状态估计中特有的最佳测量位置问题．建立了基于后集中方法的分布参数系统的非线性状态估计器,包括状态估计偏微分方程和微分灵敏度矩阵偏微分方程,并用适当的数值计算方法实现状态估计器的求解;以一个最小化的空间域上积分函数表达最佳测量位置的目标函数,并相应地用非线性约束优化方法求解系统具有一个或多个测量时的最佳测量位置．还以壁冷式单管固定床反应器为例,讨论了各种因素对最佳测量位置的影响及其灵敏度,并得出了一些有普遍意义的结论．     

凝胶点之前区域自由基交联共聚动力学参数估计

应用拟动力学速率常数的概念和矩量法导得的动力学模型研究了甲基丙烯酸甲酯(MMA)和交联剂二甲基丙烯酸乙二酯(EGDMA)共聚物系在以偶氮二异丁腈(AIBN)引发的自由基共聚合中凝胶点之前区域的动力学,同时考察链转移剂(CTA)CBr_4的影响。提出了由实验数据估计模型参数的方法,并对凝胶点之前区域的共聚过程进行分析。凝胶点的模型预示值与实验值的符合程度表明该动力学的模型较好地描述自由基交联共聚中凝胶形成的动力学。     

TRANSFER FUNCTION MODEL ORDER AND PARAMETER ESTIMATION

Abstract. A distributed lag model with a rational transfer function is considered. We have demonstrated that the C -table can be used to determine the orders of the rational transfer function and the Padé table can be used to estimate the parameters of an identifiable transfer function. In case the model is not uniquely identified, the C -table reduces possible competing models to only a few for further examination. Padé approximant gives consistent initial values for possibly more efficient iterative procedures to estimate the coefficients of the identified model. Some asymptotic results on the estimation of the C -table and the Padé table are given. A few examples are presented to demonstrate the effectiveness of the method.     

ITERATIVE AND RECURSIVE ESTIMATION OF TRANSFER FUNCTIONS

Abstract. A unified treatment of non-linear estimation, pseudolinear regression and stochastic approximation for open-loop transfer function models is provided. Pseudolinear regression techniques are used to derive the recursive non-linear least-squares estimator, avoiding the methodological problems implicit in traditional derivations. Stochastic approximation analysis is used to investigate in a direct manner the conditions of convergence and consistency of both iterative and recursive algorithms. The various methods are compared using data for an industrial process.     

双环戊二烯聚合初始动力学的研究

对双环戊二烯聚合生成聚双环戊二烯的前期动力学进行了研究。采用的催化体系由五氯化钼和二乙基氯化铝组成,溶剂为正己烷。根据金属-碳烯活性中心引发的链式开环聚合机理确定了双环戊二烯开环聚合的动力学方程,采用多元非线性回归（Pow-ell法）拟合,得到有关参数。     

SPECTRAL DENSITY ESTIMATION FROM NONLINEARLY OBSERVED DATA

Abstract. The estimation of the spectral density function of a stationary Gaussian process at the input of an instantaneous nonlinearity is considered when the nonlinearity is known and a finite set of observations of the output process is given. A class of spectral estimates is considered and their quadratic-mean consistency is established; precise asymptotic expressions for their bias and covariance are derived and their asymptotic normality is obtained.     

ESTIMATION OF THE MULTIVARIATE AUTOREGRESSIVE MOVING AVERAGE HAVING PARAMETER RESTRICTIONS AND AN APPLICATION TO ROTATIONAL SAMPLING

Abstract. The vector autoregressive moving average model with nonlinear parametric restrictions is considered. A simple and easy-to-compute Newton-Raphson estimator is proposed that approximates the restricted maximum likelihood estimator which takes full advantage of the information contained in the restrictions. In the case when there are no parametric restrictions, our Newton-Raphson estimator is equivalent to the estimator proposed by Reinsel et al. (Maximum likelihood estimators in the multivariate autoregressive moving-average model from a generalized least squares view point. J. Time Ser. Anal. 13 (1992), 133–45). The Newton-Raphson estimation procedure also extends to the vector ARMAX model. Application of our Newton-Raphson estimation method in rotational sampling problems is discussed. Simulation results are presented for two different restricted models to illustrate the estimation procedure and compare its performance with that of two alternative procedures that ignore the parametric restrictions.     

氨性硫代硫酸盐与多硫化物混合溶液氧化动力学研究

本文研究了硫代硫酸盐及多硫化物混合溶液在通空气条件下氧化的动力学，其中多硫化物氧化速率的表达式为：dCt／dt＝，反应表观活化能为61．5kJ／mol；混合溶液氧化部分转化为，其生成速率的宏观表达式为：；同时，对混合溶液在通空气条件下氧化的机理进行了讨论。     

神木煤显微组分热解特性和热解动力学

在高压热天平上考察了神木煤显微组分在不同热解温度、压力和升温速率下的热解行为 .并利用分布活化能模型 (DAEM)研究了显微组分的热解动力学 .结果表明 :在相同的热解条件下 ,镜质组比丝质组有较高的挥发分收率 .随热解温度升高 ,镜质组和丝质组的挥发分收率增加 .热解升温速率和压力对镜质组和丝质组的挥发分收率略有影响 .DAEM的动力学处理表明 :镜质组的归一化热解速率高于丝质组 ,热解活化能较低.     

QUANTIFYING THE POSITION OF THE STATIONARY STATE TRAJECTORY BETWEEN THE MICHAELIS-MENTEN AND BRIGGS-HALDANE EQUATIONS AS A FUNCTION OF THE INITIAL ENZYME CONCENTRATION

For single intermediate enzyme kinetic systems, a relationship between a defined dimensionless parameter alpha (α) and the rate constants and initial enzyme concentration of the system was derived to describe the stationary-state trajectory of d(P)/dt versus (S) between the upper and lower bounds of the Michaelis-Menten and Briggs-Haldane systems. It was found that α is a function of E _o /k _m and the parameter Ω, which is a function of k ₂ and k ₃. The development of the α parameter provides a new method for directly estimating all the rate constants in the enzyme kinetic model, given (S) and (P) data as a function of time. This method for estimating the three rate constants and initial enzyme concentration is tested on four sets of simulated discrete (isothermal) data covering a range of different trajectories and on experimental data for the horseradish-peroxidase enzyme system.