分离式高桩基础承台抗震性能分析

通过分析现有高桩承台体系的缺点入手,引入摇摆抗震技术,提出了分离式承台系统,介绍了该体系的基本特性,并从该体系的主要力学特点出发,采用SAP2000有限元分析软件建立了开放式与限位式两种分离式承台数值模型,在分析该模型的可行性之后,在此基础上建立了简支桥梁模型,分析了几项主要的动力响应,包括墩底弯矩、边桩拔出力、墩顶位移以及承台抬起高度,最后分析了该体系的优势以及未来需要进一步研究的方向。     

旋转管式膜分离器内流体的剪切力分布

推导了稳流下旋转管式膜器环隙间流体的轴向和径向速度,得出切向和轴向剪切力解析式以及剪切力分布曲线。在非稳流下,采用函数拟合法,得出流体切向速度随半径变化的表达式及流体所受切向剪切力和分布曲线。运用端流理论,分别讨论了水力光滑膜器内和水力粗糙膜器内轴向湍流的速度分布,得出了轴向剪切力的表达式及分布曲线。     

Fatigue behaviors of Z2CND18.12N stainless steel under thermal-mechanical cycling

Tests under mechanical strain control were performed to investigate the TMF behavior of Z2CND18.12N within the temperature range between 150–550 ? C. Different strain amplitudes and phase-angles were applied. Total strain controlled low cycle fatigue test was also performed at the peak temperature of TMF cycling. The results show that the cyclic stress response of the material displayed an initial hardening regime followed by a saturation period and then cyclic softening till failure. The TMF cycling leads to the development of significant amounts of mean stress. Some life prediction models were employed to predict the TMF life of Z2CND18.12N, and the results indicate that the energy-based models provide good prediction on the thermal-mechanical fatigue behaviors of this material. An optical microscopic observation shows that the surface crack initiations and crack propagations are typically transgranular mode.     

凸显科学思维训练的计算机网络原理课程教学改革

科学思维是人类获得和发现知识的基本思维方法。在教学活动中,将知识传授与科学思维训练有机结合起来,对于增强学生的学习积极性和主动性、提升人才培养质量都是有益的。本文从教学方法改革、教学内容优化、教学实施环节、教学条件建设等方面介绍了在计算机网络原理课程中开展科学思维训练的基本做法和经验,分析了科学思维训练与专业知识学习之间的关系,指出了在课程教学中开展科学思维训练有待解决的问题。