带材翼缘长度及成型道次对简单断面型钢成型的影响

以弹塑性大变形有限元理论为基础,对槽钢成型过程作出合理简化,建立分析模型,利用MARC软件对槽钢辊弯成型进行了三维有限元数值模拟,分析得出带材翼缘长度及成型道次对槽钢成型的影响.     

型钢的冷却模拟及步进式冷床的长度计算

通过对钢材的冷却机理进行分析,并使用有限元软件对槽钢的冷却过程进行数值模拟,得出槽钢的冷却时间,从而计算出步进式冷床所需的长度尺寸。     

40a槽钢孔型设计

介绍了河钢唐钢型钢厂为满足市场需求,在经典孔型理论的基础上,辅以有限元模拟工具,开发大规格槽钢孔型系统的过程。该系统在大型钢生产线应用后,实现了400 mm高大规格40a槽钢的稳定批量生产。其成品孔、控制孔及切分孔孔型设计方法及侧壁斜度的选择,为高度300 mm以上大规格槽钢孔型设计提供了参考。     

冷弯槽钢变形过渡区长度的计算

采用能量法对冷弯槽钢的变形过程进行分析与计算 ,提出了冷弯变形过渡区的概念 ,并且推导出了冷弯变形过渡区长度的理论计算公式。为今后对冷弯成型力的研究提供了必要的保证     

40号槽钢的新孔型系统

在950/800大型轧机上轧制40号槽钢的常规孔型系统采用9孔成型,其中两个孔在950开坯机,1～3孔在第一架三辊800轧机上,第4～6孔在第二架三辊800轧机上,而第7孔在850精轧机架上。3～6号孔是半闭式的(可控制的)。在用此孔型系统轧制40号槽钢时,不能保证形成具有稳定槽缘高度的槽钢。在通过开口孔2和4时,轧件处于三辊800轧机上水平辊中,     

热轧槽钢轧后冷却过程模拟

利用有限元软件对热轧20#槽钢轧后冷却过程进行模拟,获得了轧后冷却过程温度场变化规律及典型部位的温度变化.通过实际测量值进行验证,模拟结果与实际冷却过程吻合较好.为研究槽钢轧后冷却规律提供了一种方法,对设置终轧温度及改善冷却条件提供了理论依据,进而有利于保证产品性能和减小冷却变形.对生产过程中轧制工艺制定、残余应力研究具有指导意义.     

热轧20~#槽钢冷却过程研究

利用有限元软件对热轧20#槽钢轧后冷却过程进行模拟,获得了轧后冷却过程温度场变化规律及典型部位的温度变化。通过实际测量值对模拟结果进行验证,与实际冷却过程吻合较好。为研究槽钢轧后冷却规律提供了一种方法,对设置终轧温度及改善冷却条件提供了理论依据,进而有利于保证产品性能和减小冷却变形。对生产过程中轧制工艺制定、提高产品性能及外形尺寸稳定性,具有重要意义。     

提高槽钢综合成材率的探索与实践

为进一步提高槽钢的综合成材率,济钢中型轧钢厂对生产过程进行全程跟踪,对原始数据进行统计分析处理,采取了优化坯料长度、完善孔型设计、改进导卫和提高热送比率等工艺优化措施,使得每个规格槽钢生产工艺状态达到最佳,综合成材率由99．24％提高到100．38％。     

冷弯成型数值模拟与孔型CAD集成系统

建立了冷弯成型有限条数值模拟与孔型CAD集成系统,以轧辊孔型CAD设计的结果作为数值模拟系统的初始参数,由数值模拟系统分析成型过程,将位移、应变和应力等分析结果反馈到孔型CAD系统,修改初始孔型设计,绘制轧辊图。以槽钢为例,进行了孔型设计、成型过程数值模拟以及轧辊设计,分析结果与实际生产相结合,轧辊图被工厂所采用。     

烧结台车滑板槽制作工艺改进及应用

采用槽钢为原材料制作滑板槽不仅成本高、效率低,而且存在材料浪费现象。在不改变密封结构形式以及保证密封效果的前提下,通过改进滑板槽的生产工艺,利用钢板冲压成型制作滑板槽实现了生产快速化、简单化,节约了生产成本。     

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。     

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.     

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。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.