转炉留渣双渣操作生产实践

介绍了福建三安炼钢厂的转炉留渣双渣操作,以及留渣操作中安全问题的解决措施,分析了应用留渣双渣操作工艺的石灰消耗、钢铁料耗、转炉炉龄、氧耗、冶炼周期、脱磷等效果。通过优化顶底复吹转炉留渣双渣工艺制度,提高转炉前期脱磷效果,在无铁水预处理的设备条件下可以冶炼高铬铁水,满足了对钢的洁净度要求。     

转炉留渣双渣操作生产实践

介绍了福建三安炼钢厂的转炉留渣双渣操作,以及留渣操作中安全问题的解决措施,分析了应用留渣双渣操作工艺的石灰消耗、钢铁料耗、转炉炉龄、氧耗、冶炼周期、脱磷等效果。通过优化顶底复吹转炉留渣双渣工艺制度,提高转炉前期脱磷效果,在无铁水预处理的设备条件下可以冶炼高铬铁水,满足了对钢的洁净度要求。     

氧气顶吹转炉留渣操作研究

介绍了川威集团炼钢厂80t顶底复吹转炉的留渣操作工艺,对留渣操作的条件进行了研究,结合半钢操作的工艺条件,分析了应用转炉项底复吹和溅渣护炉工艺解决留渣操作安全问题的机理。实践证明实施留渣操作对转炉冶炼时的初期化渣和脱磷十分有利,留渣操作可以降低石灰消耗、降低钢铁料消耗、提高炉龄,显著提高经济效益。     

转炉炼钢脱磷影响因素的分析

磷在钢中作为一种有害元素,必须在冶炼过程中将其去除。脱磷是转炉冶炼最重要的任务之一。低磷钢的冶炼对转炉冶炼工艺提出了更为严格的要求。在理论分析的基础之上,通过对实际生产中数据的汇总,分析了温度、炉渣碱度、碳含量炉渣氧化性、留渣操作及双渣操作等因素对转炉脱磷效果的影响,为提高天钢转炉的脱磷效果提供了参考。结果表明,保持相对较低的熔池温度、造高碱度的炉渣、保持一定的炉渣氧化性以及留渣和双渣操作等,都有利于脱磷反应的进行。     

高氧化性炉渣条件下转炉长寿炉龄工艺研究

针对转炉冶炼超低碳品种钢终点炉渣氧化性高、黏度低,严重影响转炉炉况维护效果的情况,南钢技术人员采用了淘汰萤石助熔剂、全面使用复合化渣剂、配镁方法多元化、分阶段配镁、优化副枪操作和降低倒炉次数等手段改进操作工艺。通过使用改质剂、合理留渣溅渣,合理的补炉制度,实现了高氧化性炉渣条件下转炉长寿炉龄冶炼品种钢的目的,经济效益显著。     

30t转炉留渣操作工艺的研究与实践

本文介绍了吉林建龙炼钢厂30 t顶吹转炉的留渣操作工艺.对留渣操作工艺进行了研究,解决了留渣操作安全问题的机理.实践证明,实施留渣操作对转炉冶炼时的初期化渣和脱磷十分有利,还可以降低石灰消耗、降低钢铁料消耗、提高炉龄,取得了显著的经济效益.     

济钢120t转炉留渣操作工艺的实践

介绍了济钢集团第三炼钢厂120 t顶底复吹转炉的留渣操作工艺,对留渣操作的条件进行了研究,分析了应用转炉顶底复吹和溅渣护炉工艺解决留渣操作安全问题的机理;实施留渣操作对转炉冶炼时的初期化渣和脱磷十分有利,吨钢可以降低石灰消耗12 kg、降低钢铁料消耗5 kg,取得了显著的经济效益。     

济钢210t转炉低硅铁水冶炼攻关实践

针对低硅铁水冶炼具有的前期成渣困难,脱磷效率降低、渣层薄等技术难题,进行转炉低硅冶炼技术攻关。采用优化吹炼制度,合理的留渣操作、补加SiC提高热量、优化底吹供气制度等技术措施,有效地解决了冶炼过程中化渣困难、脱磷效率低及粘枪严重等技术难题。取得较好的效果。     

转炉冶炼高铬合金钢的工艺优化

高铬合金钢的冶炼一直是转炉冶炼的难点,包钢炼钢厂在冶炼高Cr合金钢时,通过采取调整转炉装入制度以及留渣双渣法等方式,并同时对转炉底吹进行优化。研究结果表明,底吹制度的优化保证了出钢过程大量合金的熔化,降低碳氧浓度积,为冶炼顺行提供了基础,解决了高合金冶炼的难题。     

260t转炉留渣操作实践

分析了影响留渣操作安全的因素及留渣操作对转炉冶炼相关指标的影响,提出了留渣操作安全性的工艺参数:留渣温度不高于1 489℃,兑铁速度小于1 711.57 kg/s,兑铁时间大于3 min,终点钢水氧活度小于9×10-4。实际操作过程中,应做到留渣量合适,提高热平衡计算的准确性和终点控制水平。留渣操作结果表明,在减少渣量的同时有利于转炉冶炼脱磷脱硫,降低钢铁料消耗,避免了剩钢焊渣罐现象。     

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.