自控系统在加氢反应工艺中的应用

通过对化工生产中加氢反应的危险性简要介绍,并以某药厂对加氢反应工艺自控系统改造时从自控方案选择到自控参量、主要自控设施确定及安装、校验和系统调试等主要过程实施为例,说明此种危险可行性,为药厂类加氢工艺自控系统的技术改造提供相应的参考。     

城际铁路GSM-R技术向LTE-R技术演进

LTE-R是国际铁路联盟（UIC）确定的铁路下一代宽带移动通信系统。本文从系统应用、系统架构、系统性能等方面对GSM-R和LTE-R进行对比分析,以珠三角某城际铁路为例,结合城际铁路特点,阐述了城际铁路GSM-R向LTE-R演进策略。     

模糊控制器在窑炉温度控制系统中的应用及计算机仿真

对陶瓷工业窑炉中的温度模糊控制问题进行了探讨,提出了模糊控制器在窑炉温控上的具体应用方法,并进行了计算机仿真,仿真结果表明模糊控制效果良好,具有较好的应用前景。     

Mechanical and dynamic mechanical properties of jute fibers–Novolac–epoxy composite laminates

A study was done of jute composite using a polymer matrix of epoxidized Novolac resin (ENR), diglycidyl ether of bisphenol A (DGEBA)–based epoxy, and their blends with different weight percentages of the resins. It was found that on blending ENR with DGEBA, the storage modulii at room temperature are enhanced by about 100% or more in the case of 30 and 40% ENR‐containing matrices, whereas the enhancement in the case of 20 and 12% ENR‐containing matrices is only 50% that of the pure matrix. It was also observed that the tan δ peak heights of the composites containing 30 and 40% ENR are closer to that of 20% ENR‐containing composite. The probable explanation drawn on the basis of experimental findings of DMA and mechanical analysis is that by blending ENR with DGEBA epoxy it is possible to manufacture jute composites with increased stiffness without sacrificing their ductility. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2800–2807, 2002     

Damping of vinyl acetate–n‐butyl acrylate copolymers

A photopolymerization process at room temperature was devised to copolymerize vinyl acetate (VAc) and n‐butyl acrylate (BA) mainly to prepare rubber‐like damping sheet bearing pressure‐sensitive adhesive property in this study. The investigations using both the differential scanning calorimeter and rheometric dynamic analysis show the existence of two glass transition temperatures for each copolymer. The scanning electron microscopic pictures reveal that the degree of microphase separation increases with increasing annealing time at 70°C. It was suggested that the rubbery domain (formed by the PBA blocks) disperses in the glassy domain (constituted by the PVAc blocks), making an effective damping entity. Excellent damping was observed for the copolymer samples, with the tanδ peak values as high as 1.76–1.80 at a certain temperature range and with tanδ> 0.3 at quite wide temperature ranges. In addition, the copolymers containing more VAc tend to have the higher damping. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1396–1403, 2004     

多CPU控制器在大功率整流控制系统中的应用

介绍了利用多CPU来设计整流控制器，解决大功率整流装置产生的磁场对整流计算机控制系统产生的干扰。     

基于普通Petri网的梯形图中接通延时定时器的建模方法

针对可编程逻辑控制器(PLC)的接通延时定时器(TON),提出了其普通Petri网建模方法。将状态变量描述为库所对,将TON中的指令运算描述为变迁,从而将TON模块描述为一个普通Petri网结构。结果表明该Petri网能够准确地描述TON的动态行为,从而为PLC梯形图程序的形式化设计或验证提供了建模方法。     

基于STM32与MCX314的双核四轴运动控制器

自主设计了一种双核四轴运动控制器.该运动控制器以MCX314As与STM32为核心硬件.该控制器不仅能够完成四轴的位置、速度和S曲线的加减速控制等功能,还能够完成直线插补,任意两轴圆弧插补与任意三轴位元插补.该控制器还基于STM32配备了USB接口、SD卡接口、USART口以及CAN总线等.该设备有很强的移植性,不仅能接人大型总线网络中,还具有很强的独立工作能力.     

一种基于TL494芯片的电动车电机控制器

他励直流电动机驱动系统结构简单、性能可靠、成本低,适合在小型电动车上运行,有效的降低了电动汽车的价格,有利于电动汽车的普及。本文在分析电动车用他励直流电机工作原理的基础上,论述电机驱动系统的整体方案,并设计3KW/36V他励有刷直流电机控制器。该控制器主要通过TL494控制,包括36V铅酸蓄电池欠压保护,控制器的过热保护等功能。经实验证实该控制器达到设计指标,工作稳定可靠,满足电动车的各种运行情况,保护功能完善并具有能量回馈等功能。     

Off-line optimization and control for real time integration of a three-phase hydrogenation catalytic reactor

In order to develop and test the integration procedure, in this paper a real time process integration involving the optimization and control of the process is presented, in this case, with the two-layer approach. The used optimization algorithms were Levenberg–Marquardt and SQP that solve a non-linear least square problem subject to bounds on the variables. The two-layer approach is a hierarchical control structure where an optimization layer calculates the set points and manipulated variables to the advanced controller, which is based on the dynamic matrix control with constraints (QDMC). The non-isothermal dynamic model of the three-phase slurry catalytic reactor with appropriate solution procedure was utilized in this work (Vasco de Toledo, E. C., Santana, P. L., Maciel, M. R. W., & Maciel Filho, R. (2001). Dynamic modeling of a three-phase catalytic slurry reactor. Chemical Engineering Science, 56, 6055–6061). The model consists on mass and heat balance equations for the catalyst particles as well as for the bulk phases of gas and liquid. The model was used to describe the dynamic behavior of hydrogenation reaction of o-cresol to obtain 2-methil-cyclohexanol, in the presence of a catalyst Ni/SiO₂.