固体超强酸的进展及其改性

固体超强酸催化剂是 1970s年代才开始发展起来的一类新型催化剂 ,本文总结了固体超强酸的发展概况 ,介绍了改性固体超强酸的一些方法。     

Distributed model predictive control of switched nonlinear systems with scheduled mode transitions

A method for the design of distributed model predictive control (DMPC) systems for a class of switched nonlinear systems for which the mode transitions take place according to a prescribed switching schedule is presented. Under appropriate stabilizability assumptions on the existence of a set of feedback controllers that can stabilize the closed‐loop switched, nonlinear system, a cooperative DMPC architecture using Lyapunov‐based model predictive control (MPC) in which the distributed controllers carry out their calculations in parallel and communicate in an iterative fashion to compute their control actions is designed. The proposed DMPC design is applied to a nonlinear chemical process network with scheduled mode transitions and its performance and computational efficiency properties in comparison to a centralized MPC architecture are evaluated through simulations. © 2013 American Institute of Chemical Engineers AIChE J, 59:860‐871, 2013     

Modeling and control of protein crystal shape and size in batch crystallization

In this work, the modeling and control of a batch crystallization process used to produce tetragonal hen egg white lysozyme crystals are studied. Two processes are considered, crystal nucleation and growth. Crystal nucleation rates are obtained from previous experiments. The growth of each crystal progresses via kinetic Monte Carlo simulations comprising of adsorption, desorption, and migration on the (110) and (101) faces. The expressions of the rate equations are similar to Durbin and Feher. To control the nucleation and growth of the protein crystals and produce a crystal population with desired shape and size, a model predictive control (MPC) strategy is implemented. Specifically, the steady‐state growth rates for the (110) and (101) faces are computed and their ratio is expressed in terms of the temperature and protein concentration via a nonlinear algebraic equation. The MPC method is shown to successfully regulate both the crystal size and shape distributions to different set‐point values. © 2013 American Institute of Chemical Engineers AIChE J, 59: 2317–2327, 2013     

磷酸二铵装置的节能减排技术——磷复肥装置节能减排技术之二

结合磷复肥行业节能减排技术的发展趋势和陕西华山化工集团有限公司复肥厂的生产实际,阐述了磷酸二铵(DAP)装置中节能减排技术的应用和改造,分析、评价其工艺特点和运行效果.     

恒切削力加工过程的神经网络预测控制

切削过程恒力控制对于提高生产率、保证加工精度具有重要作用。文章以车削加工过程为对象,研究恒切削力加工过程中当切削深度发生突变时,如何减少系统输出切削力超调的问题。将预测控制策略与神经网络理论相结合,在神经网络学习时,使切削进给在切削深度发生突变前提前发生相应变化,提出了恒力切削过程的神经网络预测控制算法。仿真结果表明,与传统自适应神经网络控制相比,加工过程的神经网络预测控制能够有效的解决在背吃刀量发生突变时,加工系统输出的切削力过大的问题,显示出比加工过程传统神经网络自适应控制更好的综合性能。     

Regulation of film thickness, surface roughness and porosity in thin film growth using deposition rate

This work focuses on distributed control of film thickness, surface roughness and porosity in a porous thin film deposition process using the deposition rate as the manipulated input. The deposition process includes adsorption and migration processes and it is modeled via kinetic Monte Carlo simulation on a triangular lattice with vacancies and overhangs allowed to develop inside the film. A distributed parameter (partial differential equation) dynamic model is derived to describe the evolution of the surface height profile of the thin film accounting for the effect of deposition rate. The dynamics of film porosity, evaluated as film site occupancy ratio, are described by an ordinary differential equation. The developed dynamic models are then used as the basis for the design of a model predictive control algorithm that includes penalty on the deviation of film thickness, surface roughness and film porosity from their respective set-point values. Simulation results demonstrate the applicability and effectiveness of the proposed modeling and control approach in the context of the deposition process under consideration.     

A Practical Method for Targeted Library Design Balancing Lead‐like Properties with Diversity

Choosing the right compounds to synthesise from large virtual combinatorial libraries is a current challenge for the pharmaceutical industry. Herein we describe a highly optimised method that aligns lead‐like properties with compound diversity. The methods are illustrated by considering a two‐dimensional library based on the interesting spirocyclic bis‐azetidine template.

     

污水处理过程的多目标多模型预测控制方法研究

针对污水处理过程节能降耗问题以及污水处理过程的高度非线性、强耦合、不确定性等特点.以基于活性污泥2号模型ASM2的A2/O污水处理过程为研究对象,提出了污水处理过程的多目标多模型预测控制方法.该方法首先采用聚类-PLS方法建立污水过程的多模型预测模型,然后构建了包含出水水质区间控制和经济性能指标的多目标优化结构的预测控制策略.仿真结果表明,与设定值预测控制方法相比,多目标优化预测控制策略在保证出水水质的前提下,能有效地节约能耗费用.     

过氧化氢合成二氧化硫脲研究进展

评述以水为溶剂间歇法合成二氧化硫脲的工艺,介绍了在提高收率、延长产品保质期等方面的技术状况和最新进展,讨论了影响产品收率的因素,如物料百分比,溶剂,反应温度,反应时间,添加剂种类,投料方式,pH值等。并对我国二氧化硫脲产业发展进行了展望。     

延迟焦化加热炉的自适应状态反馈预测控制和专家控制

An adaptive state feedback predictive control （SFPC） scheme and an expert control scheme are presented and applied to the temperature control of a 1200 kt·a^-1 delayed coking furnace, which is the key equipment for the delayed coking process. Adaptive SFPC is used to improve the performance of temperature control in normal operation. A simplified nonlinear model on the basis of first principles of the furnace is developed to obtain a state space model by linearization. Taking advantage of the nonlinear model, an online model adapting method is presented to accommodate the dynamic change of process characteristics because of tube coking and load changes. To compensate the large inverse response of outlet temperature resulting from the sudden increase of injected steam of a particular velocity to tubes, a monitoring method and an expert control scheme based on heat balance calculation are proposed. Industrial implementation shows the effectiveness and feasibility of the proposed control strategy.