熔窑内玻璃液流动与传热模型实验的新准则

熔窑内玻璃液流动与传热模型实验由于无法同时满足３个相似准则Ｒｅ，Ｇｒ和Ｐｒ相等，通常采用只保证两个相似准则 Ｒｅ，Ｇｒ相等而忽略 Ｐｒ准则的方法。分析表明，Ｐｒ对液流速度场和温度场却有强烈影响。基于熔窖内玻璃液的流动特点，由流动与传热控制方程导出了熔窑玻璃液流模型实验的两个新准则Ｇｒ／Ｒｅ和Ｐｅ。这两个新准则综合了 Ｒｅ，Ｇｒ和Ｐｒ ３个相似准则的作用，因此模型实验的相似性可得到实质性的改进，实验设计和操作也可更加方便。这种新的熔窑玻璃液流模型实验方法的有效性通过数值计算得到了验证。     

河工动床模型研究述评

以河工动床模型相似准数分析、模拟试验条件和典型情况下关键相似准则的选用为基础，比较河工动床模型校验方法的优缺点，总结了动术模型的研究水平和发展趋势，指出：河工动术模型尚处在主要进行定性相似模拟研究的水平，若理论没有突破而仅靠加大模型尺度则不能明显提高研究成果的可信度，微尺度河工动床模型值得认真关注和积极探索。     

Similarity Solution for Convection Heat Transfer Due to Marangoni Flow over a Flat Surface

IntroductionMarangoni convection occurs around vaporbubblesduring nucleation and growth of the vapor bubblesdue to the surface tension variation caused bytemperature and/or concentration variations alongthe bubble surface.Experimental tests andnumerical analyses of nucleate boiling have shownthat the heat transfer due to Marangoni flow canbe significant under microgravity and may also beimportant in earth gravity[1,2 ] .Marangoni inducedflow is also of importance in crystal growth meltswhere t…     

分形论与非晶态硅薄膜中的分形凝聚

阐述了分形概念及其在非晶硅薄膜微结构分析中的应用.利用透射电子显微镜(TEM)观测,在不同退火温度下,采用不同于常规的原位动态观测技术,获得a-Si:H薄膜中微结构形貌像.通过两种方法计算了分形结构的分维.结果表明,分形结构与a-Si:H薄膜的性质密切相关.对a-Si:H薄膜中的分形结构与晶化之间的关系进行了讨论。     

关于周期元素的相似性

本文笔者根据物质世界存在着普遍联系的观点、从相似现象的角度、对元素周期系中元素间存在着广泛的相似性、并着重对周期元素的水平相似性问题进行了初步讨论。从不同角度认识周期元素的相似性对于元素周期系的深入研讨和教学都是有益的。     

Pollen indication to source plants in the eastern desert of China

Pollen analysis is one of the important resources for the reconstruction of palaeoclimate and palaeovegetation. The relationship between modern pollen and vegetation is the foundation of pollen analysis. Owing to its complexity and importance, many polynologists and plant-ecologists have been studying on it[1―17]. In 1963, M. B. Davis gave the definition of R-values[2] that have carried forward the quantitative relationship between pollen and vegetation. However, R-value is changeable for d…     

MC-Tree: Dynamic Index Structure for Partially Clustered Multi-Dimensional Database

Index structure that enables efficient similarity queries in high-dimensional space is crucial for many applications. This paper discusses the indexing problem in dataset composed of partially clustered data, which exists in many applications. Current index methods are inefficient with partially clustered datasets. The dynamic and adaptive index structure presented here, called a multi-cluster tree (MC-tree), consists of a set of height-balanced trees for indexing. This index structure improves the querying efficiency in three ways: 1) Most bounding regions achieve uniform distributions, which results in fewer splits and less overlap compared with a single indexing tree. 2) The clusters in the dataset are dynamically detected when the index is updated. 3) The query process does not involve a sequential scan. The MC-tree was shown to be better than hierarchical and cluster-based indexes for the partially clustered datasets.     

基于相似度的复杂数据对象比较

针对包含多种类型属性的复杂数据对象在比较时的难题，给出了它们之间的一种比较方法．该方法引入了相似度的概念，给出了相应的复杂对象相似度的计算方法．该方法使复杂对象不同属性的类型和取值范围差异对比较结果的影响减小，使得比较简单化，便于常规排序算法的应用。