热轧带钢的冷却参数与翘曲关系

针对卷取温度为500℃的12 mm厚X70管线钢热轧带钢,利用MARC有限元软件建立层流冷却过程中的热-力-相变耦合的数学模型,计算两种下上冷却水比时层流冷却过程中温度场、应力、应变、相变体积分数和翘曲度随时间的变化.结果表明:1.25水比的冷却过程中,厚度方向上各面的冷却速度不一致,导致水冷前期带钢上下表面应变不同,带钢会产生向上的翘曲,冷却过程中边部最大的翘曲量达到21.84 mm;水冷后期带钢板形会逐渐恢复平直,但由于水冷过程中发生塑性变形,终冷时厚度方向上贝氏体含量的差异,卷取时带钢边部依然有-9 mm的翘曲量.上下表面的不均匀冷却是引起翘曲的根本原因.在保证X70管线钢性能条件下,采用1.58的下上水比工艺,卷取时边部翘曲量仅为-0.58 mm,合适的下上水比能大幅度减小层流冷却过程中带钢的横向翘曲.      

基于Ansys有限元的带钢层流冷却工艺的确定

采用Ansys对不同厚度带钢的层流冷却过程进行瞬态有限元模拟。得到了不同时刻带钢的温度变化和带钢宽度方向的位移变化;分析了在不同冷却工艺下带钢的温度场和应力分布;以某钢厂的层流冷却设备参数为例,来探讨不同厚度带钢的层流冷却工艺,为现场生产提供参考依据。     

济钢1700层流冷却关键参数优化

为提高济钢1700层流冷却过程中带钢冷却的均匀性,减小带钢冷却不均带来的附加残余应力,建立了层流上下水量关系和侧喷的数学优化模型,对层流上下水量配比和侧喷角度两个关键参数进行了优化,根据优化结果制定了相应的层流标定标准并在现场进行了应用。结果表明,优化后的层流上下水量和侧喷参数能够改善带钢延厚度和宽度方向冷却的均匀性,减小了层流带水和各类板形不良现象。     

南钢超快冷工艺技术生产X70管线钢的组织性能研究

通过扫描电子显微镜(SEM)、电子背散射衍射系统(EBSD)和透射电子显微镜(TEM)等方法,针对基于超快速冷却技术(UFC)、减量化成分及工艺设计生产的X70管线钢进行组织和性能分析研究,结果表明:试制X70管线钢的组织为典型针状铁素体,组织尺寸细小均匀,交错排列,达到了细晶强化和韧化的效果;强度、塑性、冲击韧性和厚度方向组织均匀性均好于应用传统层流冷却工艺获得的各项性能;屈服强度、抗拉强度、延伸率和冲击值等各项性能都符合质量标准,且性能稳定。以超快速冷却技术为核心的新一代TMCP工艺具有良好的应用前景。     

边部遮蔽在中厚板冷却中的研究与应用

中厚板控冷过程中存在集管冷却时钢板横向温度不均匀造成钢板变形的现象,采用边部遮蔽的方法能减小边部冷却不均匀性.分析了采用边部遮蔽后的钢板横向流量;并用有限元分析方法,模拟分析了不同厚度、宽度、集管流量下的温度场,确定最佳遮蔽量,开发了边部遮蔽数学模型,可以用于层流冷却系统边部遮蔽的计算机控制.     

焊瓶钢热连轧层流水喷射工艺优化实践

介绍了热轧带钢层流冷却系统水冷喷射的工艺优化过程。通过优化层流冷却过程的前段冷却水量,调整上下集管流量配比和侧喷角度,粗化了带钢的晶粒尺寸,优化前后屈强比由0.78降为0.75,伸长率平均由33%增加为36%,同时带钢的冷却均匀性改善提高了产品冲压性能的稳定性,满足了客户的后续加工要求。     

热轧带钢层流冷却过程温度场研究

 建立了热轧带钢层流冷却过程中温度场的三维有限元模型,对3 mm厚带钢轧后冷却过程带钢温度场进行模拟计算,得出卷取温度比现场测量值低9.5 ℃,相对误差为1.42%,验证了模型和假设的合理性。研究了上喷嘴直径对带钢温度的影响,带钢上表面宽度方向上存在2种不同的冷却区域：位于喷嘴正下方层流冷却过程中交替经过冲击区和平流区的区域和位于两喷嘴之间层流冷却过程中只经过平流区的区域,这造成带钢宽度方向上温度分布不均匀。计算结果表明,喷水量保持不变的情况下,存在一个最佳喷嘴直径,使带钢宽度方向上温度分布更均匀。喷水速度保持不变,增加喷嘴的直径有利于带钢宽度上方温度均匀,但增加了喷水量,降低了带钢的卷取温度。     

氧化性杀菌剂对X70管线钢电化学腐蚀的影响

采用动电位极化和电化学阻抗方法，研究了X70管线钢在加入不同浓度氧化性杀菌剂(二氯异氰尿酸钠)的层流冷却水中的电化学腐蚀行为。极化曲线表明，随着层流冷却水中加入氧化性杀菌剂浓度的增大，X70管线钢的腐蚀电流密度(Icorr)呈逐渐上升的趋势。EIS结果表明，随着氧化性杀菌剂浓度的增大，电荷转移电阻逐渐减小，电化学反应的...     

MULPIC对X70管线钢板型和性能的影响

通过调节MULPIC模型的流量值和上、下集管的水比,并对头尾遮挡的长度和流量进行调整,保证了X70管线钢的良好板型;通过调整冷却速度和终冷温度,保证了钢板的性能。     

轧制工艺对X70耐酸管线钢抗HIC和力学性能的影响

研究了终轧温度和在线冷却方式对X70级耐酸管线钢力学性能和抗HIC性能的影响。结果显示:层流冷却相对于在线空冷,钢板的强韧性有明显提高,两种工艺下钢板的硬度指标相当;在相同冷却工艺下,提高终轧温度有利于屈服强度和抗拉强度的提高;抗HIC性能只与铸坯质量有关,与轧制工艺、组织状态、晶粒度大小无关。根据研究的结果进行了X70级别耐酸管线钢的工业试制,所得X70管线钢在强韧性满足标准要求的前提下,保持了良好的抗HIC性能。     

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。     

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。     

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.     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

参与式农业基地建设行动方案设计

为了编制实用性强的基地建设行动方案,首先,确定参与式发展的主体,搭建一个"决策框架";其次,针对行动目标,提出不同参与主体,如管理者、农民、消费者等团队与个人的目标及行动内容;最后,工作应向重塑伙伴式合作关系,挖掘农民自我发展潜力,完成三大角色的转换,打造农业基地文化等方向推进.