调速永磁同步电动机传动系统仿真研究

提出了调速永磁同步电动机传动系统的仿真模型，通过仿真，对传动系统中定子电流算法、速度控制器、速度控制器输出的限幅和电机的停转过程进行了研究，确定了有关控制策略和控制参数，为传动系统的设计和系统的实际调整提供了重要的依据。     

F—D直流传动系统实时仿真

建立了Ｆ－Ｄ直流传动系统的数学仿真模型，与ＡＤＤ－３２数字控制器进行联机实时调试，考查了励磁环、电枢环、转速环的闭环控制。实验表明仿真曲线与参数和实际基本吻合。证明数学模型和仿真程序是正确的。     

唐钢无头轧制多级传动系统

介绍唐钢无头连续轧制传动系统的主回路方案，基于PROFIBUS总线的全数字多级传动控制系统配置及传动控制策略。重点介绍了其中自动位置控制系统的构成及其模糊控制器的设计方法，对传统的比例积分调节器和模糊控制器分别进行了理论分析和仿真研究，给出了现场运行结果。     

带T400工艺板的交直交变频器在2250热轧厂卷取机的应用

首钢迁安钢铁有限责任公司2250热轧厂热连轧生产线2台卷取机的传动系统采用德国Siemens公司全套带单独励磁的交直交变频器。在卷筒主传动变频控制器中采用了T400工艺板,实现了转子初始定位控制、带钢卷取的张力控制和速度控制等功能。文章介绍了传动系统的组成及特点、传动矢量控制原理、卷取张力控制等。运行结果表明,交直交变频器的控制及卷取控制的性能指标和动态性能良好。     

交——交变频器供电的同步电动机(中)

二、闭环控制控制快速转矩是调节传动系统的一个重要指标。电动机轴上的传矩应该传递到上一级控制系统,如速度控制器所要求的数值,而且延迟时间要尽量短;变流器供电的直流传动就是如此。在直流传动的情况下,转矩受电枢电流的影响。一旦电流控制器和变频器调节负载     

二十辊轧机轧制打滑与扭振动力学建模及振动特性分析

轧制过程中,轧制速度的波动和传动系统的扭转振动,都将导致轧辊与带钢表面之间产生相对滑动,严重影响带钢表面质量.为更进一步研究轧辊与带钢打滑特性,建立了森吉米尔二十辊轧机传动系统打滑扭振动力学模型,对不同轧制速度和不同摩擦系数时轧辊扭矩的动力学进行了仿真分析,通过与实验数据的对比,验证了动力学模型的有效性,为分析轧制打滑时扭矩波动提供了新的、完善的分析模型.     

精轧机主传动动态速降成因研究及改进

武钢CSP分厂精轧机主传动系统从2009年投产以来在轧机咬钢的瞬间多次发生动态速降并不能及时恢复,造成精轧机内多次废钢、撞坏机械和管网等设备、连铸机10多次断浇等停机事故,严重影响CSP分厂的正常生产。通过对主传动系统的关键数据进行长期监控,研究不同钢种、负荷、速度下的主传动系统动态速降波形曲线,建立精轧机主传动系统的仿真模型,并对各种动态速降补偿方法的效果进行分析,采取改进措施,解除了因速降而停机的故障。     

湿式双离合器自动变速器换挡控制与仿真分析

建立了湿式双离合器自动变速器(dual clutch transmission,DCT)换挡过程系统动力学模型,针对湿式双离合器系统的高度非线性、难以建立精确数学模型等特点,设计了多规则因子模糊控制器.制定了湿式双离合器换挡过程控制策略,该控制策略通过综合控制发动机和离合器压力来完成换挡过程中的动力切换.基于Matlab/Simulink软件平台,建立了湿式DCT传动系统的仿真模型,对换挡过程进行了仿真.结果表明,该控制策略能够满足DCT换挡过程的要求,并且控制器的跟踪性能良好.最后,讨论了换挡控制的影响因素.     

起停式曲柄飞剪剪切力能参数计算及仿真分析

建立了带飞轮的起停式曲柄飞剪机剪切力能参数的计算模型。剪切轧件所需剪切功由传动系统释放动能提供,可根据电机起动力矩确定电机功率。曲柄转动速度变化规律和飞轮尺寸决定了传动系统释放的动能、电机能否在允许转角和允许时间内起动以及剪刃水平分速是否满足飞剪速度的要求。以马钢VMC40N棒材飞剪机为例进行了仿真。结果表明,用该模型确定起停式曲柄飞剪机剪切力能参数并用于轧件剪切力能检验及同类飞剪的设计是可行的。     

数控自动停车系统的研制

用ＭＣＳ－５１单片机对可逆轧机停车控制系统进行技术改造，提高了轧制效率、停车精度及产品合格率。该系统的主要设备包括光电转速传感器，单片机控制系统，可编程序控制器（ＰＬＣ）和直流传动系统等。重点介绍准确停车控制系统的工作原理，单片机控制系统的开发以及对可编程序控制器的改进。     

Evidence for a regulatory protein involved in the increased activity of system A for neutral amino acid transport in osmotically stressed mammalian cells

System A for neutral amino acid transport is increased by hypertonic shock in NBL-1 cells previously induced to express system A activity by amino acid starvation. The hypertonicity-mediated effect can be blocked by cycloheximide but is insensitive to tunicamycin. The activity induced may be inactivated irreversibly by the addition of system A substrates, by a rapid mechanism insensitive to cycloheximide. In CHO-K1 cells, hypertonicity increases system A activity, as has been shown in NBL-1 cells. This effect is additive to the activity produced by derepression of system A by amino acid starvation and is insensitive to tunicamycin. Furthermore, the alanine-resistant mutant CHO-K1 alar4, which bears a mutation affecting the regulatory gene R1, involved in the derepression of system A activity after amino acid starvation, is still able to respond to the hypertonic shock by increasing system A activity to a level similar to that described in hypertonicity-induced derepressed CHO-K1 (wild type) cells. These results suggest (i) that the hypertonicity-mediated increase of system A activity occurs through a mechanism other than that involved in system A derepression and (ii) that a regulatory protein coded by an osmotically sensitive gene is responsible for further activation of preexisting A carriers.     

Dependence of adaptative regulation for IL-1 beta action on system A activity in human synovial cells

Human synovial cells are a suitable model for estimating the physiopathological effects of IL-1 beta (IL-1) in joint. Given the importance of this cytokine in the modulation of cell metabolic activities, we set out to study the action of IL-1 on the neutral amino acid transport A system, using the methyl (aminoisobutyric) acid (MeAIB), the most highly specific and nonmetabolizable substrate for the A system. Stimulation of system A activity by adaptative regulation is a prerequisite to obtain an increase of MeAIB uptake in IL-1-treated cells, since cells which had been grown in a normal medium did not express stimulation of system A activity when IL-1 was added. The IL-1-mediated MeAIB uptake is independent of protein synthesis, since cycloheximide (CHX) did not inhibit MeAIB uptake, and characterized by a decrease in the Michaelis constant K(m) (0.147 vs. 0.270 mmol/l, IL-1 vs. control) and a slight increase in maximal velocity (Vmax) (4.59 vs. 3.89 nmol/mg prot/10 min, IL-1 vs. control). These observations indicate that IL-1 induces modifications in both system A transporter affinity and number. Moreover, we indicate that system A should be responsive in vivo to IL-1 in the same way since derepression and IL-1 action occurred in the presence of human synovial fluid.     

CAI在《金属学》教学中的应用

本文介绍了《金属学》教学情况，分析了在《金属学》教学中引入CAI手段的必要性．重点论述了相图CAI系统的构成、研制技术及使用方法；对于软件中动画效果的实现，提出了画面质量的改进算法；最后分析了该系统的使用情况．     

改进的KF模型在SiO2-CaO-MnO熔渣体系中的应用

基于KF模型和Gaye模型,得到改进的KF模型,并推导出三元体系的表达式。把该模型应用到三元SiO2-CaO-MnO熔渣体系,通过对二元系研究得到模型参数,从而可计算三元系中组元的活度。结果表明计算结果与实验结果的相对偏差分别为：SM＊nO1 823K=19.3%,SM＊nO1 773K=28.1%。表明该理论在SiO2-CaO-MnO熔渣体系的应用是可行的。     

全连续冷连轧机自动控制系统的料流跟踪

在全连续冷连轧机自动控制系统中,料流跟踪是一个协调控制系统工作的基本功能,负责完成整条生产线上的带钢运行状态在计算机系统中的映像。料流跟踪功能贯穿L2级、L1级和L0级,实现过程和方式比较复杂。本文介绍了河北中钢1 250 mm八辊五机架全连续冷连轧机自动控制系统的料流跟踪。     

Pex17p of Saccharomyces cerevisiae is a novel peroxin and component of the peroxisomal protein translocation machinery

The function of the human papillomavirus type 11 (HPV 11) E1--E4 spliced protein is not known. E1--E4 protein in HPV-infected tissue is detected in the cytoplasm of differentiated epithelial cells and as immunoreactive bands corresponding to potential monomers, dimers and trimers in immunoblots. The yeast two-hybrid system was employed to test for self association of the HPV 11 E1--E4 protein. To confirm the results of the yeast two-hybrid experiments, coimmunofluorescence studies of a green fluorescent fusion protein (GFP-E1--E4) and a T7 epitope-tagged E1--E4 protein were performed in C33a keratinocytes. E1--E4 protein was shown to self associate in the yeast two-hybrid system, and this result was confirmed by colocalization of GFP-E1--E4 and T7-E1(wedge)E4 proteins in keratinocytes. Analysis of E1--E4 mutants established that the C-terminus was required for self association and that sequences in the N-terminus influenced the intracellular localization of E1--E4 protein. The intracellular expression patterns of GFP-E1--E4 and GFP-E1--E4 mutants were correlated with E1--E4 binding in the yeast two-hybrid system. Those E1--E4 mutants that did not self associate in the yeast two-hybrid system were detected as diffuse cellular fluorescence when expressed as GFP fusions. In contrast, GFP-E1--E4 was detected as a perinuclear aggregate. All E1--E4 mutants capable of associating with E1--E4 in the yeast two-hybrid system were detected as aggregates when expressed as GFP fusion proteins in keratinocytes.     

副枪自动化控制系统

济钢第三炼钢厂副枪自动化控制系统采用SDM模型实现自动化炼钢。该系统由L1级电气控制系统和L2级SDM工艺控制模型组成,L1级电气控制系统负责采集冶炼过程中钢水的温度和成分并直接传送到L2级上,SDM工艺控制模型根据接收到的数据,计算补吹模型,实行动态炼钢。     

MedWatch program

In horses reproductive performance is usually expressed as the foaling rate. This rate ranges from 40% to 80%. Three major factors contribute to this variation namely, the stallion, the mare and management. In this study, the performance of Shetland ponies kept in three different breeding systems was investigated retrospectively. In one breeding system, the stud farmer travelled with his stallion (n = 9) to the mare (system 1) while in another system, the stallion (n = 3) stayed at the stud farm and the mares came to the stallion (system 2). The last system was pasture breeding (system 3; n = 9). Each stallion participated in only one system. The average number of cycles per mare used for breeding did not differ significantly between systems 1 and 2. However, the number of matings per cycle was higher in system 2 than in system 1. The average number of mares serviced per stallion was 91, 50, and 17 for systems 1, 2 and 3, respectively. Mares mated in pasture had a 2.8-fold higher chance (p < 0.05) of having a foal the next season than the mares mated under systems 1 and 2. The foaling rate per season was 58%, 48%, and 80% for systems 1, 2 and 3, respectively. Management aspects play an important role in the relatively low foaling percentages of systems 1 and 2.     

基于新型趋近律和扰动观测器的永磁同步电机滑模控制

为了提高永磁同步电机的转速控制性能,克服扰动对伺服控制的影响,提出了一种基于新型趋近律和扰动观测器的滑模控制方法.设计了一种新型趋近律,以解决传统趋近律滑模面趋近时间和系统抖振之间的矛盾,提高系统响应快速性.综合考虑系统存在内部参数摄动和外部负载扰动,设计了滑模扰动观测器,并将观测值前馈补偿到速度控制器输出端;将观测器切换增益设计为扰动观测误差的函数,以削弱滑模观测值抖振.仿真结果显示,与传统趋近律相比,采用新型趋近律可有效提高系统的响应速度,快速准确的跟踪速度阶跃信号;滑模观测器可准确的观测系统扰动的变化;当系统加入负载扰动时,PI控制最大转速波动值为75 r·min-1,而基于新型趋近律和扰动观测器的滑模控制最大转速波动值较小为30 r·min-1,鲁棒性更好.实验结果显示,采用基于新型趋近律和扰动观测器的滑模控制方法可以快速跟踪400 r·min-1的速度指令,调节时间为0.12 s,稳态跟踪误差为±4 r·min-1,且转速无超调;滑模观测器可准确无超调的估计系统扰动值,进一步提高系统的抗扰动性能;当电机以400 r·min-1稳速运行时,加入0.6 N·m的负载扰动,基于新型趋近律和扰动观测器的滑模控制方法最大转速波动为23 r·min-1,与PI控制相比,转速波动减小了8%.上述仿真和实验结果具有较好的一致性,表明基于新型趋近律和扰动观测器的滑模控制方法可以有效抑制滑模控制系统的抖振,提高转速控制系统的鲁棒性和动态响应性能.      

炼铁优化专家系统在济钢高炉的应用

概述炼铁优化专家系统在济钢第一炼铁厂1^#高炉上的应用情况。增加2台工业PC作为优化站,与已有计算机系统组成高炉控制室的计算机局域网。通过深入开发系统优化软件模块,实现高炉冶炼过程的在线优化、智能化操作与管理,进而实现炼铁厂的数据资源共享与管理的优化决策。