韶钢中板厂厚控系统存在的问题及改进措施

本文分析了韶钢中板厂液压AGC厚度自动控制系统在调试运行过程存在的问题,制定并实施了改进措施后,该系统运行情况得到改善,取得了明显的效果,极大地提高了系统的稳定性。     

铝冷轧机液压IGC厚控系统

本文介绍从德国KRUPP公司引进的铝冷轧机板厚辊缝控制系统 并对辊缝测量装置以及IGC(Ingap Gauge Control)厚控系统的组成进行了分析和研究。     

提高薄板厂1#冷轧机的厚控精度的探讨

通过对薄板厂1#冷轧机厚度控制系统工作原理进行详细分析后发现,整个系统存在弯辊压力不足,液压执行机构响应缓慢,工作辊高速运转时容易产生跳动以及轧机在不同速度段存在共振等现象,这些因素是影响1#轧机不能有效产出厚度≤0．3mm产品的主要原因。针对以上问题提出了相应的解决措施,并在实际生产中加以应用,取得了比较好的效果,从而在一定程度上缓解了2#冷轧机的生产压力。     

Achenbach铝箔轧机控制系统常见故障处理

介绍Achenbach铝箔轧机厚控系统、VC辊、磁尺、伺服阀、测厚仪等控制系统常见的故障现象,并结合现场工作经验,分析故障产生的原因及处理故障的措施。     

液压厚调系统快速预估控制

将基于差分方程的快速预估算法引入到多被控对象领域中,在两个被控对象特性不同而要求有相同的输出过程时,取得了良好的控制效果.该算法在液压厚调系统的实际应用中,有效地解决了由于两侧压下油缸动态特性的不一致对板材纵横向厚差产生的不良影响。     

冷轧机轧辊偏心补偿信号的给定方法分析

阐述了轧辊偏心补偿的基本原理及常用方法,分析了加入偏心信号以后厚控系统的数学模型.通过仿真,给出了液压AGC系统位置闭环时间常数与偏心补偿量超前相角之间的关系,并对轧制速度变化所引起的超前相角的调整量做出了分析.     

利用Web和COM技术实现轧机厚控系统的远程调试

介绍了如何利用Ｗｅｂ和ＣＯＭ技术实现对轧机厚控系统的远程调试，以及基于ＷｉｎｄｏｗｓＤＮＡ三层架构的软件设计，分析了实时数据和非实时数据在基于ＩＰ的网络中的传输方法。     

HCW轧机内辊缝闭环厚控系统的弯辊力补偿方法

分析了HCW轧机内辊缝闭环时弯辊力变化对带材厚度的影响 ;针对西南精密带钢厂HCW 6 5 0mm轧机的实际影响情况 ,回归了在线补偿数学模型。运行结果表明 ,提出的处理方法很好地解决了工作辊轴移和弯辊力变化对带材厚度的影响。     

引进冷连轧机厚控系统分析及改进方案

武钢、宝钢两套冷连轧机代表了冷连轧技术发展水平 ,用连轧张力理论对这两套冷连轧机的厚控系统作了深入的分析、讨论 ,给出了其中最主要厚控环节 -连轧AGC和张力AGC的数学模型。对宝钢厚控系统提出了改进方案 ,利用DAGC可以简便地实现穿带、正常轧制、抛尾 ,而不用分别采用APC、恒压力、压力AGC三种控制方式 ,并且DAGC实现恒压力控制有更高的稳定性。     

液压驱动厚铝箔纵剪机组控制系统浅析

本文对国骨首创液压驱动双轴卷取的厚铝箔纵剪机组用并联液压系统本身特性实现两根卷取轴上的带卷在整个剪切过程中带材的线速和张力始终保持一致的张力匹配,速度协调、机－液、电－体化控制系统作了定性的分析。     

Longitudinal analysis of the role of perceived self-efficacy for self-regulated learning in academic continuance and achievement.

The present study examined the developmental course of perceived efficacy for self-regulated learning and its contribution to academic achievement and likelihood of remaining in school in a sample of 412 Italian students (48% males and 52% females ranging in age from 12 to 22 years). Latent growth curve analysis revealed a progressive decline in self-regulatory efficacy from junior to senior high school, with males experiencing the greater reduction. The lower the decline in self-regulatory efficacy, the higher the high school grades and the greater the likelihood of remaining in high school controlling for socioeconomic status. Reciprocal cross-lagged models revealed that high perceived efficacy for self-regulated learning in junior high school contributed to junior high school grades and self-regulatory efficacy in high school, which partially mediated the relation of junior high grades on high school grades and the likelihood of remaining in school. Socioeconomic status contributed to high school grades only mediationally through junior high grades and to school drop out both directly and mediationally through junior high grades. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perceptual categorizations of love and anger cues in schizophrenics.

The 1st study identified 4 filmed scenes indicative of high love, high anger, medium love, and medium anger. The 2nd study compared 30 good premorbid schizophrenics and 30 normals on the high love and high anger scenes. They were not differentiated on the high love scene. On the high anger scene, the normals reported significantly more anger than the good premorbids. The 3rd study evaluated 48 poor premorbid schizophrenics, 48 good premorbid schizophrenics, and 48 normals on 4 scenes of high love, high anger, medium love, and medium anger. The good premorbids and the normals were not different on the high love scene, but significantly different from the poor premorbids. On the high anger scene, good and poor premorbids were significantly different from normals. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

高碳高速钢轧辊制造工艺研究现状及展望

轧钢工业的发展对轧辊性能提出了更高的要求 ,为适应这一要求 ,开发了高碳高速钢轧辊。普通铸造方法制造高碳高速钢轧辊 ,组织粗大 ,共晶碳化物呈网状分布 ,韧性低 ,抗疲劳性能差 ,使用寿命短。变质处理和电磁搅拌是改善钢铁材料组织和性能的重要手段 ,对高碳高速钢进行变质处理和电磁搅拌研究 ,有望明显改善其组织和性能 ,为普通铸造方法制造高性能高碳高速钢轧辊奠定基础。     

Control, motivation, affect, and strategic self-regulation in the college classroom: A multidimensional phenomenon.

This study of 397 undergraduate students examined relations between self-reported control, goal orientation, future time perspective, affect, and strategic self-regulation. Five patterns were found in three canonical dimensions. The high end of bipolar Dimension 1 linked high self-regulated strategy use and study effort to high self-efficacy, outcome expectancy, and effort causal attribution; high mastery and performance approach and low work avoidance goal orientations; and positive affect. The low end of Dimension 1 linked low strategy use and effort to low self-efficacy, outcome expectancy, and effort causal attribution; high work avoidance goal orientation; and low affect. The high end of bipolar Dimension 2 linked knowledge-building strategies, but not active self-regulation or study effort, to high self-efficacy, outcome expectancy for learning but not grades, and affect causal attribution; high mastery goal orientation; and positive affect. The low end of Dimension 2 linked surface learning, consisting of active self-regulation and study effort but not personal knowledge building, to high effort causal attribution but low self-efficacy and outcome expectancy. Unipolar Dimension 3 linked learned helplessness to high outcome expectancy and external causal attribution but low self-efficacy; high work avoidance goal orientation; and high negative affect and anxiety. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

碳纤维镀镍

碳纤维是一种新型的高强度、高模量材料,具有良好的导电能力.以镀镍碳纤维增强的复合材料具有高的比强度、比模量、比刚度和良好的高温性能及尺寸稳定性.本文介绍了碳纤维表面化学镀镍及电镀镍的原理和工艺流程,其中镀前预处理对整个施镀过程至关重要.化学镀镍除Ni-P体系外还有Ni-B体系.     

超高强钛合金研究进展

随着新一代航空航天飞行器向着高速化、大型化、结构复杂化以及提高燃油效率等方向的跨越式发展,要求钛合金结构材料具有高比强度、高比模量、高韧性、高损伤容限、低成本以及可焊接等优良的综合性能匹配。此外,航天、兵器、船舶等武器装备各框梁类承力构件、承力螺栓等紧固件、高强度弹簧等弹性元件、航母弹射器与装甲等均对高强度钛合金、超高强度钛合金提出了明确需求。因此,超高强度钛合金成为了新一代武器装备发展的关键支撑材料之一,是钛合金开发和应用研究的重点方向,更是各国政府关注和重点发展的新型军用先进材料。介绍了国内外主要超高强度钛合金(TB8,TB-13,Ti-B19,Ti-B20,GUM,β21S和Timetal-LCB等)的发展和应用情况,指出了超高强度钛合金存在强度不断提高的同时,塑性、韧性、模量、疲劳性能以及损伤容限性能不同程度地降低,同时缺乏对合金化机制、强韧化理论和方法等基础问题的深入系统研究。最后提出了超高强度钛合金的发展方向。     

GaN基材料的特性及光电器件应用

GaN具有禁带宽度大、热导率高、电子饱和漂移速度大,以及介电常数小等特点,因此,它们在 高亮度发光二极管、短波长激光二极管、高性能紫外探测器,以及在高温、高频、大功率半导体器件等领域有 着广泛的应用前景。     

21世纪图书馆员的特征

论述了信息人员的六大特征：高素质性、高创造性、高强度性、高收入注、高流动性和高责任性,认为信息人员的这些特征就是图书馆员的发展方向,图书馆员最终发展归缩是信息人。     

高氮不锈钢的开发进展

加压冶炼高氮不锈钢是材料研究的一个新领域。介绍了高氮不锈钢的生产工艺及高压冶炼高氮不锈钢的主要设备。综述了欧美、日本等研发的高氮不锈钢的成分、力学性能及应用现状。由于受试验装备的限制,国内高氮不锈钢的研究与国外相比还有差距。针对高氮不锈钢具有多种优良性能,以及氮应用于对人体无害的生物、医疗材料方面前景广阔,提出医疗用高氮不锈钢将成为理想的生态材料。     

汽车排气歧管用球墨铸铁的显微组织和抗生长性

通过LOM、XRD、SEM和EDS等手段分析了汽车排气歧管材料的组织构成。高温工作后两种材料尺寸的变化随工作温度的升高逐渐增大,但高硅钼球墨铸铁的尺寸增幅明显大于高镍球墨铸铁的增幅。由于镍和锰能有效提高球墨铸铁的抗氧化性和相变温度,所以高镍球墨铸铁的抗生长性优于高硅钼球墨铸铁的抗生长性。