大型H型钢轧制热力耦合模拟及腹板波浪分析

针对在大型H型钢的轧制过程进行了全轧程热力耦合模拟仿真,并对现场生产中出现的腹板波浪及开裂问题进行了研究。本文选取HN800×300规格的典型H型钢产品进行全轧程热力耦合仿真分析,获得了轧制过程的应力应变场云图,截面金属流动规律及温度场变化规律;并在调整腿腰延伸比的情况下,对腹板轧制波浪进行了研究。分析了腹板轧制波浪的形成机理并通过模拟予以验证。通过大量的仿真工况,最后确定了在相应的孔型中,H型钢万能轧制过程中出现腹板波浪的腿腰延伸比的临界值。     

H型钢矫裂探析

通过对H型钢矫直过程中的金相组织、矫直压力大小对轧件产生的残余变形与残余应力的分析,以及轧制过程与冷却过程对矫直的影响,从而找出H型钢矫裂的原因.     

大型H型钢的矫直过程应力分布规律数值模拟分析

建立了大型H型钢九辊定棍距矫直的实体模型和有限元模型,对大型H型钢九辊连续矫直过程的弹塑性变形问题进行模拟研究,分析矫直过程中大型H型钢出现的应力变化,对具有矫前缺陷的大型H型钢矫直过程中的应力进行分析,为进一步分析H型钢矫后的残余应力控制奠定理论基础。     

H型钢轧制腹板波浪的研究

对H型钢轧制过程中腹板波浪的产生机理及形成条件进行了研究.首先利用解析的方法给出了腹板产生屈曲的临界应力和应变.使用有限元软件MSC.Marc,建立了H型钢轧制的弹塑性有限元模型,并成功地仿真出了腹板屈曲现象,给出了此过程中轧件的应力和变形规律.得到了出现腹板波浪时腹板和翼缘相对压下量的临界比值和半波长等特征值参数.     

H型钢矫裂的探析

通过对H型钢矫直过程中的金相组织、矫直压力大小对轧件产生的残余变形与残余应力的分析，以及轧制过程与冷却过程对矫直的影响，从而找出H型钢矫裂的原因。     

H型钢轧制腹板波浪的研究

 对H型钢轧制过程中腹板波浪的产生机理及形成条件进行了研究。利用解析的方法,给出了腹板产生屈曲的临界应力和应变。使用有限元软件MSC.Marc, 建立了H型钢轧制的弹塑性有限元模型,并成功地仿真出了腹板屈曲现象,给出了此过程中轧件的应力和变形规律。得到了出现腹板波浪时腹板和翼缘相对压下量的临界比值和半波长等特征值参数。     

矫直过程对H型钢残余应力影响规律的仿真计算

根据实测温度场的数据,模拟了H700×300热轧H型钢在冷却过程中的温度场和残余热应力场分布,对带有初始残余应力的H型钢九辊连续矫直过程进行了有限元仿真,得出了矫直过程对H型钢残余应力的影响规律。     

典型中型窄翼缘H型钢工艺优化研究与应用

分析了典型中型窄翼缘H型钢生产工艺中的难题及限制经济技术指标提升的原因。通过采取粗轧孔型系统的优化、激光合金熔覆技术的应用、优化精轧机组压下量分配、离线工装精度的提高、矫直精整工序设备精度的恢复及适应性改造等措施,解决了窄翼缘H型钢腹板波浪与翼缘尺寸难以控制的问题。提升了该类H型钢成材率。     

H型钢辊式矫直过程残余应力理论研究

H型钢辊式矫直过程及矫直后的残余应力对其承载能力有很大影响,传统上以残余几何形态评价矫直效果存在一定不足.基于弹塑性理论,对辊式矫直过程中H型钢断面上弹性核高度和残余应力进行了理论研究,推导出了相关解析公式,结合实例计算及仿真,验证了解析公式的正确性,对现场工艺参数的制定提供了理论依据.     

首钢低残余应力开平船板的生产工艺及变形分析

开平船板中存在很大的残余应力,导致切割下料和焊接后发生变形,这是制约开平船板广泛使用的瓶颈。 对首钢开平矫直船板下料和焊接变形进行试验分析,试验表明通过采用合理的低残余应力开平船板的工艺控制技 术来优化钢卷内的残余应力分布,使得首钢公司生产的开平矫直船板中的残余应力分布均匀,因此下料变形和焊 接变形小,能满足生产的需要。     

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.