连续退火炉内钢带稳定运行张力分析

在连续退火机组,为了保证钢带的稳定运行,必须给钢带施加一定的张力并进行稳定控制,防止钢带发生瓢曲和跑偏。分析了连续退火机组钢带工艺张力设定的基本原则,在高温工艺段,为防止钢带发生瓢曲,钢带张力要小于钢带瓢曲的临界张力;在连续退火炉外或退火炉的低温段,为防止钢带发生跑偏,钢带张力要保证钢带和辊子表面的包角,充分发挥辊子对钢带的拘束和纠偏作用。另外,调整钢带的张力还要考虑设备能力,比如钢带在辊面的包角、辊子的传动马达功率、辊面粗糙度等。     

二次冷轧机组张力辊设计计算

介绍了张力辊的工作原理及设计计算方法,并结合某钢厂二次冷轧机组设备的使用要求,对张力辊进行了设计计算.     

连续退火机组入口张力辊装置方案设计

以连续退火机组入口张力辊为研究对象,介绍了入口张力辊组的设计原理、结构和设计方法,对提供初张力时的张力辊压辊电机功率进行了计算,并就入口张力辊在两种不同工况下张力辊电机功率进行了详细的论述计算。     

双张紧辊组配置下连退机组清洗段的张力控制模式探讨

某新建连退机组清洗段采用的是双张紧辊组配置方式,其中1号张紧辊位于清洗段入口,作为速度主控制辊;2号张紧辊位于清洗段出口,用于清洗段张力控制（张力计在清洗段入口）;其他辅助辊子（沉没辊、转向辊）也采用速度控制。在此控制方式下,出现过张力控制不稳定,2号张紧辊过载及带钢跑偏的问题。针对某连退机组的清洗段出现的这些问题,提出对张力控制的建议,主要是：在设计上尽量减少张力计与2号张紧辊之间的距离,同时辅助辊参与张力调节,提高控制快速性;平衡清洗段各辊子电机负荷,以降低辊子磨损和跑偏,防止2号张紧辊电机过负载。     

带钢机组张力辊计算和设计研究

对常见的二辊式、三辊式、四辊式等张力辊进行了详细的理论分析,讨论并推导出张力辊的基本参数（象辊直径、传动功率等）的计算公式;结合几种典型实际机组进行计算、分析和比较,得出选择张力辊形式以及摩擦系数、张力放大倍数等一般规律,并结合实际工程数据,证明理论和实际基本一致,为类似机组的张力辊设计、调试及操作提供理论和实践依据。     

压延铜箔在线退火机组关键辊组设计分析

文章结合压延铜箔在线退火机组的研发和调试过程,对随动辊选型、辊径理论计算、张力辊选型及辊组布置方案进行了详细讨论,并在本机组设计条件的基础上,给出了张力辊组辊数、各张力辊所需电机功率及功率分配的定量计算过程,对铜箔在线后处理装备的设计、改造、生产都具有借鉴价值。     

宝钢冷轧某机组张力辊断裂的失效分析

宝钢冷轧某机组经过一次大的工艺及装备改造,重新投入运行后7个月时间,其中一张力辊发生断裂失效故障。简要介绍事故处理经过以及辊子的结构及工况,对该辊子的断裂原因进行详细分析,通过对辊子传动侧和操作侧以及辊身的受力分析,得出在交变应力下工作的构件,并且其辊面所承受的交变应力即为对称循环交变应力的情况下,在对其进行强度校核时,必须考虑构件的持久极限。这正是改造前对该辊子进行强度校核时没有考虑的关键因素,得出这个辊子可以继续使用的错误决定,最终导致该故障的发生。给出针对机组改造后负荷的变化对该张力辊的结构进行设计变更的建议。     

冷轧连退机组清洗段带钢跑偏原因分析及解决措施

冷轧连退机组清洗段带钢往传动侧跑偏,严重时带钢边部甚至超出辊子边缘,与钢结构刮蹭,造成机组降速生产。分析认为带钢板型不好、电解槽碱液扰动和沉没辊安装精度差产生带钢两侧张力不相等是造成清洗段带钢跑偏的原因。通过对沉没辊静态时"辊子左右微旋转自适应"调整,和动态时"以偏治偏"的调整,并结合其它措施,有效解决了带钢跑偏问题。     

酸洗连轧机组张力辊设计

介绍了中冶恒通冷轧技术有限公司2号酸洗连轧生产线轧机入口张力辊的功率计算、辊子结构设计和受力分析。     

冷轧后处理机组张力辊设计计算

从张力辊几何参数和材质确定、张力计算、传动功率计算、力矩校核等方面阐述后处理线张力辊设计计算,对后处理机组中获得精确的张力值以及张力变化规律,合理匹配张力值,提高产品质量和节能降耗有着重要意义。     

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.