计算喷雾干燥塔直径和高度的数值积分法

提出了计算喷雾干燥塔直径和高度的一种新方法———数值积分法。该法在0.5≤Re≤3000的跨区间(包括部分层流区、全部过渡区和部分湍流区)内,阻力系数与雷诺数之间的关系用误差极小的多项式拟合计算式,取代图解积分法中绘制列线图时使用的误差较大的A llen公式,得出计算雾滴水平飞翔距离和雾滴减速运动下降距离的积分式,用精度很高的四阶复化高斯-勒让德数值积分法直接求出它们的值,然后算出塔径和塔高。算例表明,新方法计算简便、结果精确、易于编程用计算机计算、收敛速度快。     

数值积分法在停留时间分布统计特征值教学中的应用

计算停留时间分布统计特征值常采用数值积分的方法。教学过程中发现大部分学生对数值积分的数学过程存在一些困惑。为了帮助学生理解和掌握数值积分方法在停留时间分布统计特征值计算中的应用,本文详细地介绍了矩形法、梯形法和抛物线法（Simpson公式）三种常用的数值积分方法,并对其准确性进行了对比。     

MATLAB在化工计算中的应用

MATLAB是Mathworks公司推出的适用于科学和工程计算的数学软件系统,具有数值稳定性好,使用方便等特点,可高效地解决数值逼近、数值积分、微分方程数值解、最优化、数值线性代数等科学和工程问题.文中以化工中的3个典型计算为例,讨论了MATLAB在化工计算中的应用,结果表明:在MATLAB的环境下,编程容易、计算方便、效率高.     

基于MATLAB优化的数据校正方法

MATLAB是适用于科学和工程计算的数学软件系统,具有数值稳定件好,使用方便等特点,可高效地解决数值逼近、数值积分、微分方程数值解、最优化、数值线性代数等科学和工程问题.以化工中的2个典型例子,讨论MATLAB在化工数据校正中的应用,结果表明:利用MATLAB编程,使数据校正计算方便、效率高.     

用MATLAB计算分离工程的典型问题

MATLAB是MathWorks公司推出的一套高性能的数值计算和可视化数学软件，可以方便、快捷地解决微分方程数值解、数理统计、数值积分、线性代数、自动控制、系统仿真等方面的科学和工程问题。本文以分离工程中的4个典型问题为例，介绍了MATLAB在数值计算、绘图等方面的一些主要功能。     

气固二相流二维不等速运动的解析解(一) 总论及略去重力影响的水平不等速运动

本文用解析解及近似解析解求解了略去重力影响的水平不等速运动基本方程,从而获得了不等速运动所需时间及距离的解析计算式,其应用范围跨越三个阻力区,应用该计算式可免除目前国内外习用解法中的图解积分法或数值积分法。所得解析式可应用于工程设计计算.     

间歇精馏的计算

该文研究用正、反分段函数插值法及离散点下数值积分等数值方法进行间歇精馏的设计型计算和操作型计算;编写了通用的计算机程序;列举了应用实例.     

分数导数型粘弹性阻尼器的动力学有限元方程及数值解

采用分数导数Kelvin固体模型建立粘弹性阻尼器在外力作用下的分数阶动力学有限元方程,并利用Newmark数值积分法得到数值解.结果表明,Zhang and Shimizu分数导数数值积分法能够很好地满足精度、收敛性和稳定性等要求,通过减小时间步长能够有效减小因引入Newmark而导致的周期误差,从而提高计算精度.     

吸收塔填料层高度的解析计算

对相平衡线为曲线的低浓度吸收操作系统，提出分段计算和曲线拟合—数值积分两种解析算法。这两种方法可得到满意的计算精度，同时可用计算机进行计算，方便易行     

间歇精馏的操作方式及算法

通过对间歇蒸馏的不同的操作方式的分析，利用逐板计算方法，研究用正、反分段函数插值法和离散点下的数值积分相结合，进行间歇蒸馏的操作型计算，并编写了通用的计算机程序。     

Incorporation of Mass and Energy Integration in the Optimal Bioethanol Separation Process

A techno‐economic analysis for the separation process in bioethanol production is presented. Optimized azeotropic separation processes in conjunction with process integration (mass and energy) are considered to simultaneously enhance the results from economic and environmental points of view. Process integration improves significantly the separation process because it helps to reduce the overall energy required in the reboilers based on energy integration and additionally to diminish the amount of required solvent based on mass integration. The SYNHEAT optimization model was applied for energy integration whereas a direct recycle strategy was implemented for the mass integration process. The best separation processes obtained correspond to an integrated conventional separation sequence with energy integration to ethanol‐water mixture III and integrated optional separation sequences with energy integration to ethanol‐water mixture III, with significant savings in utility costs and possible recycling of nearly all solvent.     

REPARAMETRIZATION ASPECTS OF NUMERICAL BAYESIAN METHODOLOGY FOR AUTOREGRESSIVE MOVING-AVERAGE MODELS

Abstract. Within the context of likelihood and Bayes approaches to inference in autoregressive moving-average (ARMA) time series models, previous ideas on parameter transformation and numerical integration for implementing Bayesian procedures are reviewed. Some novel transformation ideas are introduced and their role in an efficient numerical integration approach is examined. Some comparisons of the effectivesness of different numerical integration strategies are made.     

On the optimal numerical time integration for DEM using Hertzian force models

The numerical accuracy of a selection of different time integration techniques used to solve particle motion is investigated using a normal collision employing the non-linear Hertzian contact force. The findings are compared against the linear force model where it has been found that the expected order of accuracy of higher-order integration schemes is not realised (Tuley et al., 2010). The proposed mechanism for this limitation has been cited as the errors in integration which occur across the force profile discontinuity. By investigating the characteristics of both the non-linear elastic and the non-linear damped Hertzian contact models, it has been found that higher orders of accuracy are recoverable and depends on the degree of the governing non-linear equation. The numerical errors of the linear and non-linear force models are however markedly different in character.     

基于OPC技术的生产管理信息集成方法的研究

介绍OPC技术及基于OPC技术开发的生产管理信息集成方法。该系统已在鲁南化肥厂调度预警系统中得到成功运用     

化工能量系统集成

本文叙述了讨论由换热网络及蒸汽动力系统,冷却,冷冻等公用工程系统组成的能量系统的优化集成方法作者着重阐述了广泛应用于工程节能的夹点技术及其有关的各种先进软件,通过列举多个工厂的实例,展示了能量系统集成在化工企业节能降耗工作中的重要作用。     

权重积分方法计算界面张力消除表面“寄生”流

1 INTRODUCTION In simulation of multiphase flow in fixed Eule- rian grids by the level set approach and similar meth- ods, the accurate computation of surface tension force is critical. Two popular models were developed to model surface tension force: one is referred to as the continuum surface force (CSF) model[1―3] and the other is the continuum surface stress (CSS) model[4]. Both methods are commonly used for advecting inter- faces in the level set approach[5] and VOF (vol- ume-of-…     

A Novel Cre/lox-Based Genetic Tool for Repeated,Targeted and Markerless Gene Integration in Yarrowia lipolytica

The unconventional yeast Yarrowia lipolytica is extensively applied in bioproduction fields owing to its excellent metabolite and protein production ability. Nonetheless, utilization of this promising host is still restricted by the limited availability of precise and effective gene integration tools. In this study, a novel and efficient genetic tool was developed for targeted, repeated, and markerless gene integration based on Cre/lox site-specific recombination system. The developed tool required only a single selection marker and could completely excise the unnecessary sequences. A total of three plasmids were created and seven rounds of marker-free gene integration were examined in Y. lipolytica. All the integration efficiencies remained above 90%, and analysis of the protein production and growth characteristics of the engineered strains confirmed that genome modification via the novel genetic tool was feasible. Further work also confirmed that the genetic tool was effective for the integration of other genes, loci, and strains. Thus, this study significantly promotes the application of the Cre/lox system and presents a powerful tool for genome engineering in Y. lipolytica.     

间歇化工过程热集成研究进展

间歇化工过程热集成问题的研究能够促进过程系统的可持续发展并且提高产业经济性和技术竞争力,顺应了化工发展大环境。本文介绍了以系统综合优化为目标的间歇化工过程热集成研究的发展现状,整理了早期研究的三大通用图解模型,并讨论和比较了在建模求解过程中常见算法。总结了当前研究的重点在换热网络设计优化、热储罐系统和考虑调度的热集成三个方面,并评述了与之相关的进展、瓶颈和研究意义。指出了热集成问题已成为当前间歇化工过程的研究热点,其中热集成和生产调度的协同优化十分必要,能够从系统全局的角度上给出优化方案。但由于间歇化工过程中存在较多的不确定性和约束条件,增加了热集成的研究难度,因此对间歇化工过程优化设计提出了更高的要求。