板坯连铸中间包快换工艺实践

介绍了天铁集团炼钢厂舻板坯连铸机中间包快换工艺实践,对快换中包的准备、中间包和浸入式水口的烘烤、钢水温度条件和操作过程等重要环节做了详细阐述,并对快换中包技术实施前后的技术指标进行了对比。采用快换工艺后,连浇炉数由快换前的20炉,次提高到80炉／次以上,换包成功率达到97．12％,减少了铸机停机次数,提高了铸机产能。     

实现中间包快换的生产实践

济钢第三炼钢厂通过确保快换前后的钢水温度、提高中间包及浸入式水口的烘烤质量以及采用连接件连接接头等措施,实现了中间包快换。快换时间为2～3min。中间包快换技术大大提高了铸机作业率,连浇炉数由快换前的16炉提高到48炉以上。钢水收得率由97．67％提高到97．93％,月均提高产量4094．92t。     

湘钢连铸中间包快换工艺实践

介绍了连铸的快换工艺实践;通过快换节约了生产准备时间,降低了生产成本,减轻了操作工人体力劳动强度,提高了连铸机生产效率。     

转炉炼钢用氧枪快换装置和大锥度氧枪的应用

为了实现快速炼钢,降低工人的劳动强度,氧枪快换和大锥度氧枪的应用是炼钢厂发展的必然选择。文章详细介绍了氧枪快换和大锥度氧枪的结构、性能及特点,以及在鞍钢260t转炉实际使用的情况。     

中轧机组快装快卸换辊系统的应用

莱钢锻压厂轧钢车间改变传统的换辊方式，采用快装快卸系统，使两部车的换辊时间由2h缩至5min，且减轻了工人劳动强度，降低了生产成本，轧机运行平稳，半年内即获得19．3万元的经济效益。     

三安连铸中间包快换的工艺实践

介绍了福建三安钢铁有限公司炼钢厂通过对中间包快换的认识、准备以及对快换的条件、时间和操作要点进行了阐述。实践表明，合理利用中间包快换技术，可提高连铸机作业率、钢水收得率，减少工艺、设备、人为原因造成的连铸机停机事故。减少开机、停机次数，降低开浇、停浇操作对铸坯质量的不利影响。同时更能提高设备周期管理和状态管理的水平，降低设备维修成本和提高检修人员的工时利用率，使设备计划检修率由快换前的75.9%提高到99.24%的好水平。     

水口快换机构板间吸气原因分析

为改善结晶器浸入式水口快换机构使用过程中板间吸气问题,降低浸入式水口扩孔等异常侵蚀现象,进一步减少钢水二次氧化、卷渣等对板坯质量带来的影响,保证连铸中间包长寿命浇铸,从水口快换机构安装与维护、上水口与浸入式水口端部尺寸和平整度等方面分析。结果表明:保证快换机构系统良好工况是避免板间吸气的设备基础;耐材供应商良好的机构安装及维护是避免板间吸气的操作保证;浸入式水口板面的材质、尺寸、端面平整度是避免板间吸气的材质保障。     

圆坯连铸快换中包工艺实践

介绍了太钢炼钢一厂圆坯连铸机快换中包工艺的生产准备、作业要点和注意事项。     

快速换辊操作车的设计

快速换辊就是以尽可能快的速度更换轧机的工作辊和支承辊,在带钢轧制中为了保证最终轧制质量,尤其是在冷轧时对带钢厚度和表面质量要求高,需要经常更换轧机的工作辊。花费在换辊上的时间影响了轧机的产量。在高速热连轧和冷连轧中,这个问题更为突出。采用快速换辊装置后,缩短了换辊时间、增加了轧机的生产时间,从而提高了生产率,一般可以提高产量10％左右。快速换辊     

浸入式水口快速更换装置的研究与应用

介绍了浸入式水口快换装置的结构，主要性能参数及经济效益。     

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".     

45号钢钢水洁净度的控制研究

南钢45号钢的主要问题是铸坯和轧材裂纹率高,轧材易在热墩或热墩后的机加工过程中出现不同程度的开裂。究其原因是由于钢中大量的氧化物和硫化物夹杂使得其塑性、韧性及疲劳强度降低、加工性能变坏所致。因此,通过控制转炉终点碳质量分数和出钢过程温度、增加软吹氩时间、在LF炉中提前造白渣以及加强保护浇注等措施,降低了45号钢钢中夹杂物的数量,有效的避免了加工开裂。     

The accuracy of parental recall of aspects of child development and of child rearing practices.

Retrospective accounts of child rearing obtained from parents of 3-year-olds were compared with reports they previously gave in the course of a longitudinal study begun with the birth of the child. The parents were quite inaccurate in their memory of details about child rearing practices and early development progress, in spite of the frequent rehearsal of these data due to their participation in the longitudinal study, and in spite of the relatively young age of the children. In-accuracies were greatest for items dealing with the age of weaning and toilet training, the occurrence of thumbsucking, and demand feeding. Inaccuracies tended to be in the direction of the recommendations of experts in child rearing, especially on the part of the mothers. In general, mothers recalled more correctly than fathers. (20 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessment of Performance of Seismic Isolation System of Bolu Viaduct

The Bolu viaduct is a 2.3-km-long seismically isolated structure that was nearly complete when it was struck by the 1999 Duzce earthquake in Turkey. It suffered complete failure of the seismic isolation system and narrowly avoided total collapse due to excessive superstructure movement. This paper presents an evaluation of the design of the viaduct’s seismic isolation system and an assessment of its performance in the Duzce earthquake. Evaluation of the seismic isolation system’s design has revealed that it did not meet the requirements of the AASHTO Guide Specifications for Seismic Isolation Design. Analysis of the viaduct with motions scaled in accordance with the AASHTO Guide Specifications resulted in a displacement demand of 820 mm, which is far more than the 210 mm displacement capacity of the existing isolation system. Analysis of the viaduct for a simulated near-fault motion with characteristics consistent with the site conditions resulted in an isolation system displacement demand of 1,400 mm. This indicates that, even if the isolation system had been designed in compliance with the AASHTO, it would have still suffered damage in the earthquake.     

关于黄金地质勘探技术装备水平的思考

通过分析国内外地质勘探技术装备水平的现状,针对我国黄金行业地质勘探技术装备水平相对落后而制约了黄金工业发展的局面,提出了提高黄金地质勘探技术装备现代化水平应具备的有利条件。     

Independent integration of the 300 t BOF of Zhanjiang in heritage of steelmaking technologies of Baosteel

Through summary and extraction of current steelmaking design,process and equipment technologies and production technologies for 300 t grade converters in Baosteel,the article analyzes and elaborates the significance of independent integration of 300 t grade converters in Zhanjiang,major targets of the independent integration in converter process technologies,equipment packages and controls,the innovated critical technologies and comparison with overseas advanced technologies,major technical difficulties in the integration in Baosteel and their solutions,as well as general mindset and final objectives of the project.The total integration of technology for Shanghai No.1 Steel Making Plant of Baosteel was undertaken by Nippon Steel.And Kawasaki Steel was responsible for the total integration of technology for 4# and 5# converters of Shanghai No.2 Steelmaking Plant of Baosteel.Based on digestion,absorption and innovation of the introduced technologies,Baosteel has firstly achieved the independent integration of 6# converter,5# RH and 3# LF projects in the Shanghai No.2 Steelmaking Plant of Baosteel.Therefore, Baosteel shall take advantages of the favorable conditions and experiences and advanced steel making technologies of Baosteeel to master the imported new steelmaking technologies in the world and then form the advanced complete set steel making technologies and equipment at home and abroad.The achievement of independent integration of Zhanjiang Steel Making Project will make the breakthrough for the construction of large - sized steel making plant in Baosteel.300 t converter technology integration is undertaken by Baosteel independently in instead of by the foreign side in the past.     

铝型材氧化层局部厚度测量结果测量不确定度评定

为分析影响金属和氧化物覆盖层厚度测量不确定度的各种因素和表征测量结果的分散性, 根据测量不确定度原理和JJF1059-1999《测量不确定度评定与表示》的方法,以显微镜法测量铝型材氧化层局部厚度为例,对氧化层不均匀性和测量重复性、制样过程中横断面的斜度、测量过程中测量仪器的准确度、直读式目镜测微尺读数时数值修约5种因素引起的不确定度分量进行了评定,在此基础上计算得到合成标准不确定度和扩展不确定度,给出了铝型材氧化层局部厚度测量结果的表示方式。     

Inspection and Process of Tension of Cables of General Rafael Urdaneta Bridge

In 1997 and 1999, inspection works were carried out in the 384 cable stays of the six central piers of General Rafael Urdaneta Bridge, located in Maracaibo, Venezuela. Inspection indicated the presence of water and significant settlings in the sockets of the cables and corrosion along each cable and socket. The tension of the cables was also measured, and differences of up to 30% in the tension of the cables of some of the 24 groups corresponding to the six central piers (four groups of 16 for each pier) were found. The results suggested the need to retension the cables. This paper shows the outcome of the inspection and indicates the procedure and results of the process of retension, finished in July 2000.     

帘线钢凝固过程夹杂物生成热力学及工业实践

 非金属夹杂物是影响帘线钢拉拔性能的重要因素之一,为了研究帘线钢中夹杂物的生成及转变机理,使用ASPEX自动扫描电镜观察分析了帘线钢工业生产过程中不同碱度条件下从钢液到铸坯中非金属夹杂物的转变现象,并使用FactSage7.0热力学计算软件对非金属夹杂物的转变机理进行了讨论。在高碱度条件下,钢液中非金属夹杂物主要类型为低熔点的CaO-SiO₂-Al₂O₃-MnO,铸坯中非金属夹杂物的CaO和MnO含量有所降低,同时SiO₂含量有所增加。在低碱度炉次中,钢液中非金属夹杂物主要为较高熔点的SiO₂-MnO-CaO类型,Al₂O₃含量较低。连铸坯中非金属夹杂物的SiO₂含量与钢液相比有所增加,同时MnO含量降低。热力学计算结果表明,帘线钢凝固和冷却过程中的非金属夹杂物转变由夹杂物自身的相转变和析出、非金属夹杂物和钢液间的化学反应以及溶解氧和钢基体化学成分的反应3方面原因造成。热力学计算结果较好地解释了帘线钢工业生产中钢液和铸坯中非金属夹杂物成分和形貌的转变,为帘线钢中非金属夹杂物的控制提供参考。     

壁式采场上覆岩层力学结构分析

根据实验和现场预测结果，提出了壁式采场上覆岩层中存在抛物线形拱结构，建立了该结构力学模型，并进行了内力分析，同时提出了工作面支架受载的计算方法。