Generation of anisotropic mesh by ellipse packing over an unbounded domain

With the advance of the finite element method, general fluid dynamic and traffic flow problems with arbitrary boundary definition over an unbounded domain are tackled. This paper describes an algorithm for the generation of anisotropic mesh of variable element size over an unbounded 2D domain by using the advancing front ellipse packing technique. Unlike the conventional frontal method, the procedure does not start from the object boundary but starts from a convenient point within an open domain. The sequence of construction of the packing ellipses is determined by the shortest distance from the fictitious centre in such a way that the generation front is more or less a circular loop with occasional minor concave parts due to element size variation. As soon as an ellipse is added to the generation front, finite elements are directly generated by properly connecting frontal segments with the centre of the new ellipse. Ellipses are packed closely and in contact with the existing ellipses by an iterative procedure according to the specified anisotropic metric tensor. The anisotropic meshes generated by ellipse packing can also be used through a mapping process to produce parametric surface meshes of various characteristics. The size and the orientation of the ellipses in the pack are controlled by the metric tensor as derived from the principal surface curvatures. In contrast to other mesh generation schemes, the domain boundary is not considered in the process of ellipse packing, this reduces a lot of geometrical checks for intersection between frontal segments. Five examples are given to show the effectiveness and robustness of anisotropic mesh generation and the application of ellipse packing to mesh generation over various curved surfaces.     

Coupling of anionic wetting agents to dust of sulfide ores by dropping liquid method

By using the experimental approach of dropping liquid, the coupling of three anionic wetting agents with ten dust samples of sulfide ores was studied, and particularly the wetting effects of the wetting agents on the sulfide dust influenced by factors of agent concentration and sulfate additive in the wetting agent solutions were investigated. The results show that when the solution temperature is about 20℃, all the selected wetting agents are effective to most dust samples, but the effect is different. Wetting agents are more effective to the dust which is difficult to be wetted. Wetting agent solution with sodium sulfate can improve the wetting ability of sulfide dust. For sodium dodecyl benzene sulfonate, the suitable concentration of sodium sulfate is 1 - 2 mmol/L. The cost of wetting agents can be reduced because the sodium sulfate is much cheaper than many surfactants. Since the dust of sulfide ores is composed of various minerals and elements, the whole effect of depressing dust should be considered while innovating a wetting agent.     

铜金粉表面改性技术的研究

为了提高铜金粉的表面其泽度采用3种表面活性剂对铜金粉进行表面改性研究,从而证明降低粘结料对铜金粉的润湿性,可提高粉末在粘结料中的漂浮性能,有效提高铜金粉颜料的印金光泽度。探明了铜金粉颜料化处理的原理和努力的方向。同时分析了表面活性剂的种类及其浓度对铜金粉印金光泽度的影响。结果表明,铜金粉的润湿性随表面活性剂浓度变化而存在极值点;复合改性剂比硬脂酸系列的改性剂能更好的降低铜金粉的润湿性。     

关于文化研究的几个热点和前沿问题

自上世纪80年代以来，文化问题成为社会关注的热点和学术研究的前沿，对文化研究中的一些重大前沿问题，诸如现代化建设与传统文化、文化激进主义与文化保守主义、全球化中的民族文化、科技文化与人文文化、文化的世俗性与超越性等的研讨情况作出了简要评述。     

Numerical investigation of thermocapillary migration of the drop for large Marangoni numbers

An axisymmetric model is adopted to simulate the problem of unsteady drop thermocapillary motion for large Marangoni numbers. Front tracking methods are used in the investigation. It is found that the non-dimensional drop migration velocity will decrease with increasing Marangoni number. This agrees well with the experimental results obtained from the 4th Shen-Zhou space ship. In the meanwhile, this is also the first time for numerical simulations to verify the experimental phenomenon under large Marangoni numbers. Recommended by Prof. WANG ZhanGuo, Member of Editorial Committee of Science in China, Series E: Technological Sciences Supported by Chinese Academy of Sciencer Innovation Program and the National Natural Science Foundation of China (Grant Nos. G10502054, G10432060)     

引黄工程总干三级泵站侧向进水前池水工模型试验研究

介绍了通过水工模型试验提出的引黄入晋工程总干三级泵站侧向进水前池的优化体型及为调整水流结构而采取的整流板等工程措施，这些措施使泵站进水前池中水流流态平稳，流速分布均匀，避免了在各种工况下前池中产生螺旋流及水面串通漏斗漩涡，能保证水泵安全、正常、高效运行。     

关于建立高校大统战机制的若干思考

高校是知识分子密集的部门，也是统战工作的重要阵地，新世纪对统一战线工作提出了更高的要求，进一步做好高校统战工作显得更为迫切和重要。本结合我国工作实际，阐述了统战部在大统战机制中的作用，并对构建大统战机制提出了若干建议。     

波前法在大型塑性成形有限元模拟中的应用

开发了用FORTRAN语言实现的波前法求解有限元线性化方程组的完整系统，并应用在形状复杂的带阻尼台叶片的精锻过程的三维有限元分析中对其进行了考核。结果表明，波前法在求解大型线性化方程组方面有着很大的优越性；所开发的系统主要适用于塑性加工过程大型三维有限元的高效率、高精度模拟分析。     

新时期加强高校统战工作的研究与实践

加强和改进高校统战工作，已成为高校各级党组织理论研究和实践探索的重要课题。分析新形势下党外知识分子思想状况的新特点、新问题和党外知识分子工作面临的新变化，提出高校党委及各级党组织加强和改善对统战工作领导的对策措施并加以实践，具有重要的现实意义。     

GIS投切主变陡波前过电压的研究

对GIS(SF6气体绝缘全封闭组合电器)变电站中产生的高频暂态过电压，即陡波前过电压的产生原因、分类及危害性进行了介绍，以2个典型变电站为实例，采用EMTP计算和现场测试相结合的方法对GIS内部陡波前过电压及外部陡波前过电压进行研究，总结出一种新的确定GIS中陡波前过电压水平的方法，并提出合理化保护措施和建议。