控制冷却工艺对DH36钢板质量影响的分析研究

研究了控制冷却工艺对DH36钢板板型、微观组织和性能的影响。结果表明:DH36钢板采用弱冷水控制冷却工艺能得到良好板型,获得较理想显微组织;增加侧喷可以提高同钢板性能均匀性。采用控制冷却工艺后钢板的屈服强度和抗拉强度明显提高,性能稳定性得到显著改善。     

高强耐磨钢板直接淬火板型控制工艺研究

通过控制轧制后在线直接淬火的工艺研究,揭示耐磨钢板淬火时组织转变、热胀冷缩产生的应力应变与板型控制的关系,通过确定钢板终轧温度、入水温度、钢板上下水比、冷速等参数,确保钢板组织转变均匀、板型良好。大量实验表明,采用在线淬火工艺流程简单、效率高、节约能源。     

通过TMCP工艺改善准贝氏体耐磨钢板性能

通过控制轧制控制冷却工艺,改变各项工艺参数,来改善钢板的组织结构,提高钢板的强韧性和硬度,从而达到提高钢板综合性能的目的。     

典型热处理工艺对高强度钢板组织及性能的影响

主要研究再加热淬火+回火(RQ-T)、再结晶区控制轧制+直接淬火+回火(HR-DQ-T)和未再结晶区控制轧制+直接淬火+回火(CR-DQ-T)3种典型热处理工艺对高强度钢板力学性能及组织的影响。试验研究表明:直接淬火工艺生产钢板比再加热淬火工艺试验钢板具有更高的强度,CR-DQ工艺试验钢板具有更为优异的综合力学性能;3种工艺淬火态组织均为马氏体和少量贝氏体的板条组织,CR-DQ工艺获得的板条组织细小、取向相对混乱且相互交叉纠缠、位错密度更大。研究结果为DQ-T工艺生产高强度钢板提供了依据。     

亚包晶钢钢板小纵裂的控制

为找到控制亚包晶钢钢板小纵裂的方法,采用金相和扫描电镜检验对钢板裂纹以及连铸坯组织进行研究,发现连铸坯表层激冷层薄且厚度不均同时存在严重的魏氏组织是造成钢板小纵裂的主要原因。采用结晶器弱冷和低过热度浇注方式,有效地控制了钢板小纵裂的发生。     

中厚板Q460C轧制工艺对钢板延伸率影响的试验分析

根据Q460C钢板试样的金相组织和断口形貌特征分析,表层组织由铁素体、珠光体和少量弥散贝氏体构成,心部组织为铁素体和珠光体。晶粒尺寸细化的钢板容易得到较高延伸率,因此轧钢环节的关键是控制温度和冷却强度。如果终轧温度过低且冷却强度过大,则钢板心部组织容易出现贝氏体以及混晶现象,从而导致延伸率明显降低,影响钢板性能合格率。     

控制冷却对16Mn钢板组织和性能的影响

前言本文叙述了16Mn钢板的控制冷却实验室研究结果,分为正火控制冷却和热轧控制冷却两部分。实验结果表明,钢板的冷却速度和强制冷却的温度区间对钢板的机械性能与显微组织有明显影响。     

中厚板组织性能控制技术的发展和应用状况

中厚板生产的控制轧制、控制冷却及其相结合的TMCP技术,以及直接淬火和离线热处理技术是控制钢板组织和力学性能的重要手段。近些年新发展的性能控制技术还有IC、RPC、HOP和NCC技术,介绍了这些新技术的基本原理、技术特点和对钢板组织和力学性能的控制效果,并对各技术在生产应用中的实际问题进行了扼要的分析。     

Q420GJD高建钢的开发与研究

采用220mm连铸坯生产Q420GJD钢板,通过连铸坯中心偏析控制、有害元素控制以及大变形渗透轧制策略,获得预期的钢板组织结构和力学性能,保证钢板低温韧性和厚度方向抗层装撕裂性能标准要求。     

Q460C钢板的混晶组织特征和成因探讨

对Q460C钢板金相组织和晶粒尺寸分布进行了分析,用定量金相等方法分析了个别钢板中混晶组织的特征。结果表明,微区成分偏析和轧制工艺不当是Q460C钢板出现混晶组织的重要原因,采用合理控制各道次的变形温度和变形量,以及避免在奥氏体部分再结晶区轧制等措施可以有效改善钢板混晶问题。     

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.