Study of electron temperature gradient instability in toroidal plasmas with negative magnetic shear

Electron temperature gradient driven instability in toroidal plasmas with negative magnetic shear is studied. Full electron kinetics is considered, and the behaviours of the modes and corresponding turbulent transport in the parameter regimes close to the instability threshold are emphasized. Growing and damped modes are both investigated. The singular points of the integrand are disposed of, and the fitting formulae for the critical gradient are given. The theoretical results are shown to be close to the experimental observations.     

高效多孔层毛细管柱吸附气相色谱的研究进展

PLOT柱是用于永久性气体,低碳烃和挥发性化合物色谱分析的最有效的工具,经常用于替代经典填充柱,对多孔层开管毛细管柱（PLOT）吸附色谱的分离机理、PLOT柱制备方法和各类吸附剂的色谱特性及其特定应用进行了综述。     

谈谈理论力学教材的改革

 讨论了以复矢量法讲解刚体动力学的优点.     

热弹流润滑椭圆接触区内表面凹陷现象的研究

通过理论分析和光干涉实验 ,考察了纯滑动热弹流润滑椭圆接触区内当卷吸速度与接触椭圆短轴成 0°和 45°角时出现的油膜局部增厚现象 ,即固体表面在接触区出现凹陷的现象 .解释了玻璃盘 -钢滚子接触副表面凹陷的形成原因 ,揭示了凹陷的深度、位置和形状随卷吸速度及接触椭圆短轴夹角的变化规律 .     

湿磨工况下冲击功对高锰钢腐蚀磨损交互作用的影响

采用自制的冲击腐蚀磨损试验机模拟湿磨工况,通过电化学等方法研究了冲击工况条件下高锰钢在锡矿浆料中的腐蚀磨损行为,定量分析了腐蚀磨损中交互作用各个分量的相对比例.结果表明,虽然弱酸性的矿浆对高锰钢的腐蚀性较小,但腐蚀增量是静态腐蚀率的15.76～26.54倍,腐蚀磨损交互作用的比例为12.08%～26.70%,表明磨损与腐蚀有一定的协同促进作用.在低冲击功1 J时,交互作用是以磨损促进腐蚀为主;在冲击功为2、3、4 J时,交互作用是以腐蚀促进磨损为主.最后探讨了冲击载荷下磨损与腐蚀的交互作用机理,以及冲击功对交互作用机理的影响.     

平行间隙的热楔承载机理分析

本文研究了在4类表面温度边界条件下的热密度楔和热黏度楔对承载能力的影响,指出平行间隙内的油膜也具有承载能力,并与传统的几何楔进行了比较,分析了热密度楔和热黏度楔的关系及其重要性.除了用传统的表面温度差原理来解释平行间隙的承载机理外,还通过数值分析提出了1种补充理论,指出即使2个平行表面之间没有温度差但因油膜内部温度分布不均匀油膜也会产生承载力.     

ITER磁体重力支撑系统的应力强度分析

用ANSYS有限元软件,分析了ITER重力支撑系统的静力情况。采用实体单元建立有限元模型,分析了磁体重量、热载荷、地震和电磁力多种工况下的应力分布及位移变形,获得的最大应力强度和最大位移均在许用应力及允许位移范围内。为进一步优化ITER重力支撑系统提供了重要的参考数据。     

Topographic effects on polar low and tropical cyclone development in simple theoretical model

The polar low and tropical cyclone type vortices over topography are assumed to be the axisymmetrical and thermal-wind balanced systems, which are solved as an initial value problem of a linearized vortex equation set in cylindrical coordinates. The roles of the sensible and latent heating, friction, and topography in the structure and intensification of the polar low and tropical cyclone type vortices are analyzed. The radial velocity, vertical velocity, azimuthal velocity, and the unstable growth rate including the topography effects are obtained. It is shown that the interaction between the flow and the topography plays a significant role in the structure and intensification of the polar low and tropical cyclone system. The analysis of the topography term indicates that, in the up-slope side of the mountain, the radial inflow and the vertical ascent forced by the mountain can intensify the polar low and tropical cyclone type vortex and increase the unstable growth rate. However, in the lee side of the mountain, the radial inflow and the vertical descent forced by the mountain can weaken the polar low and tropical cyclone type vortex and decrease the unstable growth rate of the polar low and tropical cyclone system. In addition, the evolutionary process and the spatial structure of the polar low observed over the Japan Sea on 19 December 2003 are investigated with the observational data to verify this theoretical result.