基于内部非线性映射模型PLS算法的比较研究

本文从线性偏最小二乘(PlS)算法出发对基于内部非线性映射模型的PlS算法的思想本质进行深入的剖析和探讨。结合拟合非线性过程的实际问题,从拟合精度、计算复杂度两方面对基于二次函数和神经网络作为内部模型的PlS方法以及基于误差反馈调整的PlS算法进行了比较,在此基础上对不同的非线性PlS算法的应用提出了若干指导性建议

高温高压灭菌锅系统非线性参数辨识

作者简介：汤植平（1984-05），男，汉，福建省龙岩人，厦门大学硕士学位，研究方向为控制理论与控制工程。 师佳，男，汉，厦门大学副教授，博士学位，研究方向为化学化工。高温高压灭菌是食品加工业的一个重要生产过程。该过程代表的是一个多变量、非线性且多阶段操作的复杂间歇过程。精确的参数辨识是设计高温高压灭菌锅系统的基础,对灭菌锅系统的建模与仿真具有十分重要的意义。本文利用偏最小二乘算法对高温高压灭菌锅系统进行了参数辨识,同时用辨识到的参数进行了系统仿真。通过辨识结果和理论值,以及仿真结果和实际测量到系统数据的比较,表明辨识结果有较高的准确度

The Design of an Intelligent and Full Automatic Perfumery Equipment

针对香精调配过程,阐述了一种全自动调香设备的基本设计思路、系统的结构组成和工作原理。该系统包括:PC机、机械模块、电源模块、控制模块和人机界面。其主要功能是根据调香师输入的配方自动实现各种液态香料的多线程进样,并结合现有调香理论对香精性质进行仿真。它不但能够达到调香过程自动化、精确化、信息化的目的,而且有助于调香师制定配方。尽管设计的原型机只能进行3种液态香料加注,但其实验与理论的一致性证明了其潜在应用价值。This article expounds the train of thought on a full automatic equipment for perfumery, also its system structure and operational principle are explained. This system integrates personal computer, mechanism module, power supply module, control module and human-computer interface. The main function of the proposed equipment is to automatically implement the multithreading sampling of each kind of liquid flavor according to perfumers′ prescription, and simulate the property of the fragrance based on the existing perfumery theories. It could not only realize the goal of automation, informatization and precision for the perfumery process, but also help the perfumers to frame the prescription. Although the designed equipment can only process 3 kinds of liquid flavor, the conformity of the design and the experimental results indicated its potential application value.2007年国家大学生创新性实验计划项目;; 2007年福建省大学生创新性实验计划项

Online Soft-measurement for Thermal Efficiency of Circulating Fluidized Bed Boilers

提出循环流化床(Cfb)锅炉热效率的在线软测量方法,该方法将效率分为煤燃烧效率和传热效率两部分,根据Cfb锅炉动态机理模型在线计算锅炉未燃烧碳量,在此基础上计算煤燃烧效率,再通过反平衡法和正平衡法计算锅炉传热效率,最后得到锅炉热效率.应用该方法对某440T/H循环流化床锅炉热效率进行了计算,分析了影响该锅炉热效率的主要因素.结果表明:影响锅炉热效率的最主要因素是烟气中的飞灰含量;该软测量方法适用于Cfb锅炉,能有效指导锅炉调控,从而提高锅炉热效率.An online soft-measuring method for thermal efficiency of the circulating fluidized bed boiler(CFB)is being proposed.The method divides the efficiency into two parts,coal combustion efficiency and heat transfer efficiency.On-line calculation for the unburned carbon content of the boiler is carried out according to the dynamic mechanism model of the CFB boiler,after that combustion efficiency of the coal is calculated.Then heat transfer efficiency is calculated by indirect heat balance and direct heat balance,finally the boiler thermal efficiency is obtained.The thermal efficiency of certain 440 t/h CFB was calculated by the method,and the main factors which influence the thermal efficiency of the boiler were analyzed.Results show that the main factor which influences the thermal efficiency of the boiler is the content of fly ash in the flue gas.The soft-measuring method is suitable for CFB boiler,which can effectively direct the control of the boiler,thus improving the thermal efficiency of the boiler.福建省科技基金资助项目(2007J0165

Two-dimensional Model Predictive Iterative Learning Control Scheme Based on a Two-dimensional Performance Model

将迭代学习控制(ITErATIVE lEArnIng COnTrOl,IlC)系统看作一类具有2维动态特性的控制系统,根据模型预测控制(MOdEl PrEdICTIVE COnTrOl,MPC)和性能参考模型控制思想,提出了一种基于2维性能参考模型的2维模型预测迭代学习控制系统设计方案.在该控制系统设计方案中,可以通过选择适当的2维性能参考模型来构造2维动态变化的设定值信号和预测控制信号,从而引导迭代学习控制系统收敛到合理的控制性能,并有效避免系统性能收敛过程中控制输入可能发生的剧烈波动.通过对控制系统的结构分析可知,所得的迭代学习控制器本质上是由沿时间指标的参考模型预测控制器和沿周期指标的迭代学习控制器组成,闭环系统的收敛性等价于一个2维滤波系统的稳定性.数值仿真结果证明了该设计方案的有效性和鲁棒性.By representing an iterative learning control(ILC) system as a two-dimensional system and using the philosophy of model predictive control(MPC) and performance model reference control,a two-dimensional performance model based model predictive iterative learning control scheme is proposed in this paper.Through the design of two-dimensional dynamics of the performance model to generate more proper reference trajectories and predictive control signals for each cycle,the convergence pattern of the iterative learning control system can be guided to avoid the issue of possibly violent oscillation of input signal.The structure analysis indicates that the resulted control is composed of the time-wise performance model based model predictive control and cycle-wise iterative learning control,and that the convergence of the closed loop control system is equivalent to the stability of a two-dimensional filter.Numerical simulations illustrate the effectiveness and robustness of the proposed control scheme.国家自然科学基金(61174093)资助~

Steady-state simulation of fixed bed for coal gasification using ASPEN PLUS

用ASPEn PluS软件对固定床煤气化过程进行模拟,采用带fOrTrAn气化动力学子程序的串联全混流反应器来代替gIbbS反应器,能够更好地反映气化炉的真实反应情况,结果表明该模型与实际固定床煤气化的反应结果吻合较好。利用该模型研究了串联釜数对碳转化率及出口温度的影响,研究表明:随着釜数的增加,碳转化率和出口温度更加接近于实际数据;在保证模拟精度的前提下,较少的釜数有利于减少计算量。ASPEN PLUS is used to simulate the fixed bed for coal gasification process.The gasification reaction kinetics is expressed by FORTRAN subroutine in RCSTRs,and then the RSCTRS in series are used to substitute the Gibbs reactor.So the reaction condition of the gasifier can be described more accurate in the simulation and the results of the simulation are in agreement with the actual fixed bed of the coal gasification process.The proposed model was applied to study the effect of the number of RCSTRs on carbon conversion and outlet temperature.The results show that carbon conversion and outlet temperature are closer to the actual data with the number increase of RCSTRs.However,less number of RCSTRs helps to reduce the computation time.With consideration of the accuracy and computation time of the simulation for coal gasification,it is suitable to use 6 RCSTRs in series to describe the fixed bed according to the results of the simulation.中央高校基本科研业务费专项资金资助项目(2010121047

Modeling and Simulation for Sterilization Process of Canned Food

食品加工业中的罐头食品蒸汽灭菌过程是一种典型的多阶段间歇式生产过程。针对该过程,从物质守恒和能量守恒两方面,建立起通过热传递而相互关联的灭菌锅系统模型和罐头系统模型,而两者又构成了灭菌系统完整的数学模型。在此模型基础上进行了整个过程的仿真计算。通过对仿真结果与实验数据的对比,验证了所建模型的有效性。该模型为研究该类生产过程的优化控制策略提供了一个有效的模拟和测试平台。In the food industry,the sterilization of canned food is a typical multi-stage batch process.The mathematical models of the retort system and the can system were proposed on the basis of mass and energy conservation.The dynamical model of sterilization process was composed of these two subsystems which were connected by heat transfer.With the simulation of whole model,not only the accuracy of the mathematical model was demonstrated,but also an effective platform for testing was provided for the optimization and controller design for such production processes.国家自然科学基金(61174093); 中央高校基本科研业务费专项资金(2010121047

基于裂结技术的单分子尺度化学反应研究进展

分子电子学是研究单分子器件的构筑、性质以及功能调控的一门新兴学科。其中,金属/分子/金属结的构筑和表征是现阶段分子电子学的主要研究内容。裂结技术是当前分子电子学研究的主要实验方法,主要包括机械可控裂结技术和扫描隧道显微镜裂结技术。本文对裂结技术进行了介绍,并对近年来利用这些技术,在单分子尺度化学反应的检测和动力学研究,以及将这些技术与溶液环境、静电场、电化学门控等方法相结合,调控单分子器件的电输运性质等方面所取得的进展进行了概述。国家重点研发计划(2017YFA0204902);;\n福建省自然科学基金(2016J05162)资助项目~

Identifying the Conformational Isomers of Single-Molecule Cyclohexane at Room Temperature

构象异构是化学中的基本问题。然而对于环己烷等柔性分子，由于其在室温下极快的互变异构过程，基于系综的表征方法（如核磁等）只能得到所有构象平均贡献的结果。为了应对这一挑战，化学化工学院洪文晶教授与夏海平教授课题组为在室温条件下对柔性分子构象的定量分析与表征这一挑战，课题组成功实现了在室温条件下对环己烷两种椅式构象的电学表征与比例识别。同时，通过纳米电极间隙对分子的限域作用，发现在宏观尺度下极不稳定的扭船式中间体得以在单分子尺度稳定存在，这为不稳定中间体的研究提供了重要表征方法。 这一研究工作是在化学化工学院洪文晶教授、夏海平教授共同指导下完成的，iChEM直博生唐淳与化工系研究生唐永翔为论文共同第一作者。师佳副教授与刘俊扬副研究员为该工作提供了指导，博士后陈志昕、博士研究生陈李珏以及研究生叶艺玲、严哲玮、张珑漪共同参与了该工作。【Abstract】Isomerism reflects the ubiquitous nature that molecules with the same molecular formula show different structures. The interconversion between conformational isomers of flexible molecules is quite fast owing to the low barriers of around 10 kcal mol−1, leading to average signal contributed by all the possible isomers characterized by ensemble methods. On this account, identifying the conformational isomers of flexible molecules at room temperature has a substantial challenge. Here, we develop a single-molecule approach to identify the conformational isomers of cyclohexane at room temperature through the single-molecule electrical characterization. By noise analysis and feature extraction of the conductance of single-molecule junctions, we quantificationally identified two chair isomers of cyclohexane at room temperature, while such identification is only feasible at low temperatures by ensemble characterization. The strategy to apply the single-molecule approach to identify conformational isomers paves the avenue to investigate the isomerization of flexible molecules beyond the ensemble methods.This work was supported by the National Natural Science Foundation of China (nos, 21722305, 21673195, 21703188, and U1705254), the National Key R&D Program of China (2017YFA0204902), China Postdoctoral Science Foundation (no. 2017M622060), and the Fundamental Research Funds for Xiamen University (20720190002).该工作获得了科技部国家重点研发计划、国家自然科学基金等项目的资助，也得到了固体表面物理化学国家重点实验室、能源材料化学协同创新中心的支持

Anti-resonance features of destructive quantum interference in single-molecule thiophene junctions achieved by electrochemical gating

基于单个有机分子来构筑电子器件为电子器件微型化提供潜在技术方案。本研究发展了可集成电化学门控的单分子电子器件测试芯片技术和科学仪器方法，在实验和理论两个层面对具有相消量子干涉效应的噻吩衍生物分子器件的电输运过程进行了电化学调控研究，从而首次在室温下实现了对单分子电子器件中量子干涉效应的反共振现象的直接观测和调控，为制备基于量子干涉效应的新型分子材料和器件提供了全新的设计思路和策略。该研究充分展示了电化学调控技术在信息材料和器件领域的重要应用潜力，也体现了我校固体表面物理化学国家重点实验室在电化学研究和科学仪器研发领域的技术积累，以及面向科学前沿开展交叉学科探索的研究特色。 该研究工作是在洪文晶教授、上海电力大学陈文博教授、英国兰卡斯特大学Colin Lambert教授指导下完成的。化学化工学院博士生白杰和李晓慧为论文的共同第一作者，刘俊扬副研究员、师佳副教授、研究生唐永翔、刘帅、黄晓娟、谭志冰和萨本栋微纳研究院的杨杨副教授等也参与了研究工作。田中群教授和毛秉伟教授为该工作提供了重要指导。【Abstract】Controlling the electrical conductance and in particular the occurrence of quantum interference in single-molecule junctions through gating effects, has potential for the realization of high-performance functional molecular devices. In this work, we used an electrochemically-gated, mechanically-controllable break junction technique to tune the electronic behaviour of thiophene-based molecular junctions that show destructive quantum interference (DQI) features. By varying the voltage applied to the electrochemical gate at room temperature, we reached a conductance minimum that provides direct evidence of charge transport controlled by an anti-resonance arising from DQI. Our molecular system enables conductance tuning close to two orders of magnitude within the non-faradaic potential region, which is significantly higher than that achieved with molecules not showing DQI. Our experimental results, interpreted using quantum transport theory, demonstrate that electrochemical gating is a promising strategy for obtaining improved in-situ control over the electrical performance of interference-based molecular devices.This research was supported by the National Key R&D Program of China (2017YFA0204902), National Natural Science Foundation of China (21722305, 21673195, 21503179, 21703188), the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, Natural Science Foundation of Shanghai (17ZR1447100), Science and Technology Commission of Shanghai Municipality (14DZ2261000), China Postdoctoral Science Foundation (2017M622060) for funding work in Xiamen. It was also supported by EU Horizon 2020 project QuIET under grant agreement no. 767187EC FP7 ITN ‘MOLESCO’ project no. 606728 and UK EPSRC grants EP/N017188/1 and EP/M014452/1 and Leverhulme Trust (Leverhulme Early Career Fellowships no. ECF-2017-186 and ECF-2018-375) for funding instrumentation used in Lancaster. It was also supported by Hungarian and Czech Academies of Sciences (P2015-107) and Hungarian Research Foundation (OTKA 112034) for funding instrumentation used in Hungary. The authors thank Z.-Q. Tian and B.-W. Mao, Xiamen University, for useful discussions. 该工作获得科技部国家重点研发计划课题（2017YFA0204902），国家自然科学基金委优秀青年科学基金等项目（21722305、21673195、21703188、21503179）以及中国博士后科学基金（2017M622060）等项目的资助，也得到了固体表面物理化学国家重点实验室、能源材料化学协同创新中心的支持