带钢连续退火机组双偏心五辊矫直机压下量计算

 分析了现场正在使用的进口五辊矫直机的压下量调整和使用方法,结合该矫直机双偏心调整压下量的特点,经过公式推导并计算了在矫直不同材质和规格的条件下,利用双偏心轴的不同转动角度,得到上辊压下量的设定方法。计算方法对实际的生产使用和优化设计该类型的矫直机有一定的帮助。     

酸洗机组九辊矫直机压下量及电机功率分析

针对酸洗机组中带钢矫直问题,分析了九辊矫直机压下量和带钢来料厚度的关系,并介绍了对同一带材不同压下量和电机功率的关系,为计算酸洗机组中的九辊矫直机电机功率提供了理论参考。     

连续退火生产线带材翘曲治理方案的研究

在充分利用连续退火生产线现有条件的基础上,将金属矫直理论与机械布局有机结合,提出了1套实用的连续退火生产线翘曲治理方案,以1根简单的防翘辊与已有的张紧辊相组合,借助张紧辊产生的张力,通过调节该防翘辊的压下量来改变带钢与辊面的包角,运用拉弯矫直的原理有效改变了带材内部残余应力的分布,达到了完全治理带钢翘曲的目的,创造了显著的经济效益,有进一步推广应用价值。     

连续退火生产线带材翘曲治理方案的研究

在充分利用连续退火生产线现有条件的基础上,将金属矫直理论与机械布局有机结合,提出了1套实用的连续退火生产线翘曲治理方案,以1根简单的防翘辊与已有的张紧辊相组合,借助张紧辊产生的张力,通过调节该防翘辊的压下量来改变带钢与辊面的包角,运用拉弯矫直的原理有效改变了带材内部残余应力的分布,达到了完全治理带钢翘曲的目的,创造了显著的经济效益,有进一步推广应用价值。     

中厚板辊式矫直过程弯辊作用分析

 为了进一步提高中厚板产品矫直质量,采用弹塑性差分的曲率积分方法,分析了弯辊对矫直效果的影响,研究了弯辊量与压下量的关系,为建立中厚板辊式矫直过程的弯辊设定模型奠定了基础。计算结果表明,为了使板材矫直后的残余曲率和残余应力最小化,施加弯辊时要考虑入口压下量的影响。单从降低残余曲率的角度考虑,小压下量和大压下量下都可以施加负弯辊,但正弯辊只适用于小压下量。从控制宽度方向残余应力的角度考虑,正弯辊施加于小入口压下量时弯辊作用明显,为了消除正弯辊对厚度方向残余应力的不利作用,采用正弯辊时入口压下量不宜过大。施加弯辊会增加矫直力,因此设定弯辊量时要考虑矫直机能力的限制。研究发现了弯辊对塑性变形率的影响规律：负弯辊出现了使塑性变形率随着入口压下量的增加而减少的阶段,正弯辊可消除塑性变形率为零的阶段。     

拉伸弯曲矫直过程中带钢对弯曲辊包角的理论计算

在带钢的拉伸弯曲矫直变形过程中,包角的精确计算对拉伸矫直机延伸率的精确控制至关重要.在不考虑带钢抗弯力矩的影响时,带钢在各个辊上的理论包角比较容易计算,研究了对称模型包角、非对称模型包角、带钢厚度对包角的影响.在确定的设备和带钢厚度时,带钢对弯曲辊的包角取决于其压下量.     

带材边浪拉弯矫直有限元模拟研究

带材在轧制过程中由于延伸不均匀就会造成浪形或瓢区等三维板形缺陷。本文采用显式动力学有限元软件ANSYS/LS-DYNA模拟了边浪带材拉伸弯曲矫直过程,分析了边浪带材的变形,得到：1)可使带钢得到有效矫直的与张应力相匹配的弯曲辊压下量;2)边浪处的延伸与平直处的延伸趋于一致,但一个弯曲单元的矫直能力不足;3)随弯曲辊的压下量增加,张应力对带材弯曲曲率的作用增大。这些结果对具有三维缺陷的带材拉弯矫直提供了有益的参考作用。     

连杆式七辊矫直机分析及计算

以连杆式七辊矫直机为对象,通过分析力能参数计算、辊系压下量的设定及压下量精度模型的建立,为合理设定该类矫直机工作辊的压下规程、提高板带矫直质量提供了一种简便可行的方法。     

不锈钢带钢拉矫过程的变形行为分析

基于通用有限元软件(Abaqus/Standard)建立了不锈钢带钢拉伸弯曲矫直过程的有限元模型。考虑到实际不锈钢带钢拉矫过程的辊系及运动特点,该有限元模型将带钢在拉矫工艺段按照其所处的位置分为7段,针对带钢厚度方向的变形特点,沿带钢厚度方向将带钢分为7层。通过对带钢拉矫过程特征位置点经过各辊组的应力应变分析表明:带钢延伸率主要由1号弯曲辊组提供,而2号、3号矫直辊组对延伸率的贡献不明显。该研究得到的不锈钢带拉矫过程变形行为、延伸率产生机理可为拉矫工艺参数确定和优化提供理论基础。     

基于有限元法的拉伸弯曲矫直过程板形控制分析

 板形是带钢质量的重要判定指标,常见的板形缺陷有边浪、中浪、1/4浪等,其实质是残余应力在带宽上的分布不均。拉伸弯曲矫直机通过张力辊组、弯曲辊组和较真辊组的共同作用,使带钢在低于屈服强度的张力作用下发生塑性延伸,从而有效消除浪形缺陷,改善板形,提高带钢质量。然而在拉伸弯曲矫直机的设计和使用过程中,对拉伸弯曲矫直机参数的调整多基于经验,缺少理论指导。为了定量分析拉伸弯曲矫直机参数对浪形缺陷的改善效果,使拉伸弯曲矫直机在实际生产中发挥更好的作用,以某1 450 mm带钢酸洗冷轧生产线上的拉伸弯曲矫直机为研究对象,使用有限元软件ANSYS/LS-DYNA基于三维弹塑性有限元法建立了拉伸弯曲矫直机模型,对拉伸弯曲矫直机矫直过程进行了模拟,分析了张力和插入深度对初始浪形分别为边浪和中浪的带钢矫直后板形的影响规律。结果表明,经过拉伸弯曲矫直的带钢浪形缺陷得到显著改善;插入深度和张力对初始浪形缺陷分别为边浪和中浪的带钢板形的影响规律一致;3个辊组中矫直辊组的插入深度是影响带钢板形的主要因素,随着矫直辊组插入深度增大,带钢矫直后板形由边浪转变为平直,且随着矫直辊插入深度进一步增大,板形又由平直转变为边浪;随着入口张力增大,带钢矫直后板形由边浪转变为中浪。     

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。     

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。     

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.     

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.