铁路喷漆库通风探讨

介绍一种喷漆库的通风方式，着重叙述其通风系统的构成及原理     

生物高科离我们不远

在IT“知识英雄”红透全球的今天,有人预言不久的将来世界财富最大的赢家是生物科技领域。如果生物科技与IT缔结良缘,那么一个伟大的崭新的生物科技时代即将来临。当后基因组时代迅速到来之际,将给人们带来以下的改变……免疫网络综合调节研究的重大进展及“鸡尾酒疗法”的     

铁路漆库通风探讨

介绍一种喷漆库的通风方式，着重叙述其通风系统的构成及原理。     

Calculation on the incubation period of proeutectoid ferrite transformation for Si-Mn TRIP steel

The incubation period of proeutectoid ferrite transformation for Si-Mn transformation induced plasticity (TRIP) steel has been calculated by the Aaronson’s incubation period model for transformation. The influences of chemical compositions and hot deformation of austenite on the incubation period have been taken into consideration in the calculation, and some parameters have been proposed and validated with the measured time temperature transformation (TTT) curves from dilation tests. The calculation results show that it is essential to take into account of the effect of solute atoms on the interfacial energy in the austenite grain boundaries. For hypoeutectoid steel, the incubation period of ferrite transformation increases with the increase of C and Mn contents, and C has a greater impact than that of Mn, while the incubation period of ferrite transformation decreases with the increase of Si content. Hot deformation shortens the incubation time and promotes austenite to ferrite transformation.     

海上风机叶根螺栓瞬态应力分析与可靠性优化

大兆瓦海上风电机组叶根螺栓螺纹副预紧载荷分布非均匀行为是诱发螺栓在高预紧状态下预紧力早期衰退的最主要原因之一。结合海上风机叶根螺栓的预紧工艺,文章从螺纹副载荷非均匀分布行为入手,提出了一种基于螺纹副载荷分布计算的螺纹参数匹配与连接工艺优化方法。首先,构建了参数驱动的螺纹副精细化有限元瞬态动力学模型,并对螺纹牙型角、螺距等特征进行了参数化建模,计算了采用拉伸法工艺预紧叶根螺栓过程中标准螺纹副受载历程与载荷分布状态;然后,搭建了基于拉伸法工艺预紧螺栓的试验系统,以螺栓预紧力瞬时衰减值为判据验证了螺纹副载荷分布行为有限元计算模型的有效性与精度。最后,以某型10 MW级风电机组用M36高强度螺栓为工程应用对象,基于叶根螺栓拉伸法预紧工艺下螺纹副载荷分布对其螺纹特征进行了参数化适配设计。结果表明：采用本文提出的方法,有效控制了拉伸法预紧螺栓过程中的预紧力损失,降低了螺牙的最大结构应力的同时改善了螺纹副的应力分布,有利于提高风电机组的运行可靠性。