感应加热在铁路工务部门的应用

本文介绍了用涡流加热的方法更换铁路隧道螺旋道钉的技术 .该方法较好地解决了目前我国铁路部门螺旋道钉难以更换的问题 .     

一水甲酸锂晶体生长动力学和生长机理的研究

本文实时测定了312.16K时一水甲酸锂晶体(LFM)(010)和(021)面的生长速率。根据Bennema修正的用于水溶液晶体生长的BCF表面扩散模型,计算了晶体生长过程的激活能以及动力学系数。结果表明LFM晶体生长主要是表面扩散控制的螺位错生长机制。     

低温材料及低温钻杆的研发现状

随着目前深井和超深井的发展,以及北方、西北地区高寒地带油气井的开发,越来越多的钻杆要求具有抵抗低温或者超低温度的性能需要.低温钻杆成为目前极有发展前景的石油工业技术之一.文中在综述低温材料研究现状的基础上,阐述了低温材料钻杆的工艺现状及其发展趋势.     

读数显微镜基准调试装置的原理与制作

介绍了读数显微镜基准调试装置的原理、结构、实施方式与特征,以及使用方法。     

STUDY OF CREEP PARAMETERS OF GRANITE IN STEADY STATE UNDER CONDITIONS OF HIGH TEMPERATURE AND HYDROSTATIC PRESSURE

高温高压花岗岩钻孔实验表明,温度低于500℃,静水应力低于150MPa 状态下,岩体的钻孔变形均属于稳态蠕变变形阶段. 该文选取了广义开尔文模型来反映其特征,通过拉普拉斯变换及逆变换,详细推演出了钻孔径向位移解析解,并且考虑温度-应力的耦合效应,给出了模型参数随温度及应力变化的关系式. 利用该关系进行拟合计算,说明广义开尔文模型来表达高温高压环境中的花岗岩稳态蠕变变形特性,寻求蠕变参数是合理可靠的. 该文对于高温岩体地热资源开发中的钻孔施工与维护、钻孔变形量预测等方面,具有实际的指导意义.     

自组装非接触测距仪

介绍一种非接触测距仪的制作和设计理念,并对仪器的使用特点和测量精度进行了分析。     

A model of crack based on dislocations in smectic A liquid crystals

A plastic crack model for smectic A liquid crystals under longitudinal shear is suggested. The solution of the screw dislocation in smectic A is the key to the correct result that we obtained by overcoming a longstanding puzzle. We further use the dislocation pile-up principle and the singular integral equation method to construct the solution of the crack in the phase. From the solution, we can determine the size of the plastic zone at the crack tip and the crack tip opening （tearing） displacement, which are the parameters relevant to the local stability/instability of materials. Our results may be useful for developing soft-matter mechanics.     

Modeling of reactive systems in twin-screw extrusion: challenges and applications

Reactive extrusion processes involve the difficulties of mastering classical polymer processes, such as twin-screw extrusion for example, and the problems of controlling a chemical reaction in very specific conditions (high-viscosity medium, high temperatures, short residence times). Therefore, it is often very difficult to intuitively understand all the aspects of the process and to clarify the complex interactions between the numerous variables, and then to properly design and optimize the industrial process. Numerical modeling can be a very efficient tool to overcome these difficulties. However, it remains a real challenge, as it necessitates to couple flow simulation in complex geometry, reaction kinetics and evolutionary rheological behavior. Moreover, the information needed is sometimes difficult to obtain with the required accuracy. After a general presentation of the principles of the different reactive extrusion modeling methodologies, we will focus on the models we developed, based on continuum mechanics. Different examples of applications are presented for illustrating the interest of this method. To cite this article: B. Vergnes et al., C. R. Chimie 9 (2006).     

经皮中空螺钉内固定与张力带内固定内踝骨折的临床疗效观察

研究探讨经皮置入中空螺钉内固定治疗闭合性内踝骨折(Ashurst和Bromer分类的内翻内收型骨折Ⅰ度)的临床实用性,收集60例闭合性内踝骨折的患者,随机分为两组各30例。A组予传统切开复位张力带内固定术治疗,B组予闭合复位经皮置入中空螺钉内固定治疗。术后采用Takakura踝关节评分系统来评价疗效,并对结果进行分析。