连铸动态轻压下关键技术与自主开发应用进展

连铸机动态轻压下技术是解决铸坯中心偏析和中心疏松的有效手段。在总结国内外研究工作的基础上阐述了动态轻压下的关键技术,介绍了该技术的国内自主开发进展及应用效果。随着轻压下技术的广泛应用和推广,动态轻压下技术的自主研究、设计和应用已成为发展中国高端钢铁产品的必然趋势。     

动态轻压下改善板坯内部质量的应用研究

介绍了安钢动态轻压下技术及采用动态轻压下技术改善板坯内部质量的效果,分析了轻压下对中心偏析和内部裂纹的影响。     

3#宽厚板坯连铸机凝固末端轻压下技术

介绍了宝钢分公司炼钢厂3#宽厚板坯连铸机采用的凝固末端轻压下技术,简述了凝固末端轻压下技术的原理,并对其主要工艺参数轻压下凝固末端的位置及其确定方法、压下率、总压下量和压下速率进行了讨论和分析,介绍了从控制角度这种技术的几种分类方式:静态轻压下、动态轻压下和半动态轻压下.得出结论,凝固末端轻压下技术对减少中心偏析很有效.     

动态轻压下改善板坯内部质量的应用研究

介绍了安钢采用动态轻压下技术改善板坯内部质量的效果，并分析了动态轻压下对中心偏析和内部裂纹的影响。     

动态轻压下技术在大方坯连铸机上的应用

动态轻压下技术可降低铸坯中心偏析,改善铸坯中心疏松状况.本文主要介绍了动态轻压下技术的冶金原理,并根据应用效果,分析工艺参数对铸坯内部质量的影响.     

连铸动态轻压下工艺对重轨坯内部质量的改善

文章对包钢连铸动态轻压下技术的基本情况进行了介绍,并重点介绍了包钢重轨钢采用动态轻压下技术后,铸坯中心碳偏析、铸坯中心疏松以及钢轨轨腰条纹的改善情况。     

连铸大方坯动态轻压下冶金效果分析

动态轻压下技术是减轻铸坯的中心偏析与疏松缺陷、提升铸坯内部质量的有效途径.包钢新建的5号大方坯铸机的动态轻压下控制系统由北京科技大学与包钢合作设计和开发,能够在非稳态的浇注条件下进行有效的动态轻压下和动态二冷配水实时控制.针对重轨钢U71Mn、U75V等代表性钢种,在5号连铸机上进行了动态轻压下冶金效果热负荷试验.经过合理地制定试验方案、取样设计以及冶金效果分析,结果表明,采用动态轻压下工艺后,铸坯中心疏松明显减轻,中心区域等轴晶率增加,连铸坯横断面上C成分分布更加均匀,中心C偏析指数波动范围明显变窄,有效减轻了铸坯的中心偏析缺陷,铸坯内质得到明显提升.     

管线钢连铸轻压下工艺的研究

为了充分发挥铸机动态轻压下技术在提高铸坯内部质量方面的作用,进行了管线钢连铸轻压下技术的试验研究。通过分析中心偏析的形成机理,研究连铸轻压下工艺的设计原则。利用枝晶检验和化学成分分析等手段,研究不同轻压下位置对连铸坯中碳、锰、磷元素偏析的影响,从而对现行的动态轻压下位置进行了优化调整,进一步提高了管线钢连铸坯的内部质量。     

超低头板坯铸机动态轻压下技术的实现

介绍超低头铸板坯上进行机械和液压系统的改造,安装轻压下系统,实现轻压下技术的过程。经过多次调试成功实现动态轻压下功能,在板坯内部裂纹、中心疏松及中心偏析等方面取得了一定的效果,已达到提高铸坯内部质量的目的。     

《板坯连铸机动态轻压下技术的研究开发及应用》项目荣获2007年度冶金科学技术贰等奖

连铸过程中连铸坯动态轻压下技术是解决连铸坯中心偏析和疏松的理想手段，在高端产品（如高级管线钢、汽车板钢、海洋钻探平台用钢等）生产中必不可少，已成为现代连铸水平的一个显著标志，被公认为正在大力发展中的第三代连铸技术。近年来我国新引进的动态轻压下技术先后在各钢厂投入生产，但其核心工艺、控制技术均为保密，不能进行二次开发。鉴于此，2004年上海宝钢集团梅山钢铁股份有限公司联合东北大学与北京科技大学，根据国家技术创新项目《梅山板坯连铸机动态轻压下技术的研究开发与应用》，针对板坯动态轻压下机理与应用展开研究，自主开发了板坯动态轻压下核心工艺、控制模型，架构了动态轻压下过程控制系统，并于2006年7月正式投产应用。     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Concept of freedom of infection of animal flocks

Totally negative results of epidemiological investigation of random samples do not prove the absence of the infection as the pathogen may be restricted to only a few animals in the herd for a long time. The statement "absence of infection" is critical for such situations. The question is raised, whether the statement "absence of infection" should be generally avoided. Classification of herds and flocks according to the prevalence of the pathogen would be more valid for the implementation of control measures.     

显微维氏硬度测量不确定度评定

对显微维氏硬度测量不确定度进行评定，建立了不确定度计算的数学模型，确定了影响实验结果的各项因素，计算出了各因素的标准不确定度，得出结果的扩展不确定度，并给出最终测量结果的表达式。     

Comparison of the results of surgical and conservative treatment of fractures of the diaphysis of the tibia

In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.