肠造口患者的研究已经逐渐由横断面的调查研究转变到纵向的干预研究,因此有必要对如今肠造口患者自我效能感现状再次进行阶段性总结.通过对肠造口患者自我效能感的概念、现状、研究工具及影响因素进行分析,间接的为肠造口患者提供护理方向.对于目前肠造口患者自我效能感培养的措施进行适当的概括与分类,从而为护理同仁进行下一步研究提供可供参考的经验.

通过Gleeble-3500热模拟试验机测定了U75V钢（/%:0.75C,0.63Si,0.95Mn,0.025P,0.004S,0.26Cr,0.05V）的CCT相变曲线,利用DEFORM-3D有限元软件,通过建立60AT钢轨轧后空冷过程中温度场、组织转变计算模型,研究分析了60AT钢轨150~700 s轧后空冷过程中温度、组织对弯曲变形的影响。结果表明,60AT钢轨具有的大体表比轨腰对钢轨整体断面温度分布影响较大,钢轨空冷150 s时,60AT钢轨断面上还未发生相变,组织全部为奥氏体,随着温度的降低,空冷650 s时,钢轨断面基本上珠光体转变量为97.2%,同时,弯曲变形受组织转变影响较大,终冷时,钢轨在Y方向（侧弯）弯曲挠度-0.07 mm,即弯向轨底短边,在Z方向（正弯）弯曲挠度为0.228 mm,即弯向轨头,计算结果为钢轨矫直过程中的预弯提供参考。

In order to formulate and optimize the pre-bend process for heavy rails for high-speed train systems, cooling experiments and microstructure observations were conducted to determine the appropriate cooling rate. Also, the rules of bending during the cooling process were studied by the thermo-mechanical coupled finite element method (FEM). Based on the simulation results, the shape change, temperature change, and solid-state phase transformation in different areas of the rail during the entire cooling process were investigated. The obtained results can explain the occurrence of the bending process, which has great scientific and practical significance for rail production.

利用DEFORM软件定量描述了U75V钢轨轧后不同冷却过程中弯曲变形的演变规律.结果表明:钢轨冷却过程中弯曲变形不仅受热应力和相变应力作用,而且还受钢轨不同部位冷速不同、相变进行程度不同的影响.钢轨空冷过程最终弯曲变形量为0.0913 mm,换算成百米重轨为1.01 m,弯向轨头方向;而以轨头15℃/s,轨底6℃/s冷速水冷方式冷却时,钢轨最终弯曲变形量为-0.044 mm,换算成百米重轨为-0.441 m,弯向轨底方向.可见通过控制钢轨不同部位冷速,可使其弯曲变形程度较空冷的小.

In this paper, the DEFORM-3D finite element software is used to construct the models of temperature and microstructure fields of the 60AT rail during the air cooling process after rolling, with the distribution regularities of temperature and phase-transformation in air cooling analyzed. The computation results suggest that the temperature distribution along the cross section of the 60AT rail is significantly influenced by its rail web with great volume-to-surface-area ratio. At 150s during the air cooling process, there is no phase change on the cross section of the 60AT rail, with all phase that appears to be austenite. At 650s with the temperature dropped, the almost all the cross section of the rail has been turned into pearlite, with the changing rate of 97.2%. The pearlite phase change happens from the three edges of the railhead and the long and short wings of the rail flange to the railhead and the rail web, until the whole cross section of the rail is changed.

Phase transformation plasticity effect on residual stress and deformation cannot be ignored ,therefore ,the studies on the phase transformation plasticity is necessary .Based on Greenwood-Johnson theory ,using Gleeble-1500D thermal simulation ma-chine ,the transformation plasticity in the process of U 75V heavy rail steel continuous cooling transformation was studied .By measuring the expansion curve under different loading stresses ,the thermal strain ,phase transformation strain ,elastic strain and phase transformation plastic strain were separated ,and the phase transformation plasticity model of heavy rail steel was estab-lished .The results show that :in the phase change process ,the thermal strain occupies the highest proportion and accounts for more than 80% ;the proportion of the maximum phase transformation plasticity strain in the total strain increases with the in-creasing of stress ;with the loading stress -45MPa and phase transition temperature at the end point 577.1℃ ,the phase trans-formation plasticity strain accounts for the biggest proportion in the total strain reaching 12.5% .

In the paper, the ABAQUS is adopted to carry on numerical simulation on straightening process of U75V heavy rail whose chord height is 80mm under the 20.9-13.2-5.6-5.4 standard. Formation mechanisms and changing rules of the internal stress are analyzed in straightening process of different heavy rails. The results show that residual stress in rail head of 75kg/m heavy rail is larger than 60kg/m heavy rail’s and the gap is 220MPa between 75 kg/m l and 60kg/m heavy rail and the gap of residual stress is insignificant in rail waist. Residual stress in rail bottom of 75kg/m heavy rail is larger and the gap is 16MPa between 75kg/m and 60kg/m heavy rail. The residual stress can be reduced by reasonable straightening process and reasonable straightening process contributes to improving the quality and service life of rail.

In order to guarantee the requirements of H-beam microstructure and property, its must have a certain compression ratio in the rolling process from blank to finished products. This paper simulated and analyzed the law of H-beam equivalent stress change for beam blank cogging with software DEFORM. Simulation results show that the compression ratio is 10.78 in the rolling process from blank to finished products; after BD cogging, blank size meet the requirements of A hole by rolling one pass into CCS rolling, the law of H-beam equivalent stress mainly focus on the waist and haunch joint in the whole process of beam blank cogging.