Filtration of micro-particles within multi-fiber arrays by adhesive DEM-CFD simulation

A 3D multi-time scale discrete element method-computational fluid dynamic (DEM-CFD) coupling approach was applied to investigate the filtration of micron-sized particles by different types of fiber arrays. Both the pressure drop and the filtration efficiency were examined to indicate the filtration performance of the fiber arrays. Fibers that were uniformly arrayed in a parallel or staggered manner were compared. Results showed that the staggered array showed a better performance than the parallel array in terms of both pressure drop and filtration efficiency. Further, we compared the performance of different staggered arrays, i.e. a regular case, one densified in the front layers and another densified in the back layers. The front densified array was found to enter the clogging and cake filtration stage in the shortest time, leading to the highest filtration efficiency, but the highest pressure drop. The back densified array still achieved a much higher filtration efficiency, despite a much lower pressure drop comparable to that of the regular array. The results suggest that the two kinds of densified arrays may be suited for different purposes, e.g. baghouse filters or breathing masks.     

六世班禅朝觐与廓尔喀入侵

六世班禅到承德朝觐乾隆皇帝和廓尔喀入侵西藏都是在深刘而复杂的国际国内政治环境下发生的.班禅圆寂后留下了巨额财产,这直接引发了廓尔喀入侵西藏.清政府在取得了对廓尔喀的反击战胜利后,进一步改革了西藏的政治、宗教管理体制,并制定了影响深远的<钦定二十九条善后章程>.     

试评老子“无为”思想的教育价值

在当代教育借鉴中华民族传统文化的潮流中,儒家思想以刚健有为、注重主体精神的"有为"理念成为进德、修身、立业和积极入世的弘道,而以老子"无为而治"为代表的道家学理却往往被看作消极遁世、封闭落后的学识而予以否定.实际上,以老子为代表的道家"无为"理念涵化着深刻的辩证法思想和注重客观、实事求是的唯物主义原则,道家与儒家"有为"政治一起"相异相济、殊途同归",成为中华文化传承中的两大基本派别和中华文明的慧命哲学,对当代教育亦具积极的现实意义.     

英语请求语用发展研究──以探询型请求子策略之选择为例

通过语篇补全测试,调查中国英语学习者对探询型请求子策略的选择。结果发现：学习者在请求主体策略选择上呈现与英语母语者相同的序列;学习者在请求子策略选择上存在过多或不当使用某些情态词,某些话句类型使用单一的情况;角色指向性的选择上,以听话者为指向的比率较高。这些特点表明文化间既具有相通性也存在文化相异,需要在教学中积极开展明示语用教学,重视学生语言能力的培养。     

Atom Surprise: Using Theatre in Primary Science Education

Early exposure to science may have a lifelong effect on children’s attitudes towards science and their motivation to learn science in later life. Out-of-class environments can play a significant role in creating favourable attitudes, while contributing to conceptual learning. Educational science theatre is one form of an out-of-class environment, which has received little research attention. This study aims to describe affective and cognitive learning outcomes of watching such a play and to point to connections between theatrical elements and specific outcomes. “Atom Surprise” is a play portraying several concepts on the topic of matter. A mixed methods approach was adopted to investigate the knowledge and attitudes of children (grades 1–6) from two different school settings who watched the play. Data were gathered using questionnaires and in-depth interviews. Analysis suggested that in both schools children’s knowledge on the topic of matter increased after the play with younger children gaining more conceptual knowledge than their older peers. In the public school girls showed greater gains in conceptual knowledge than boys. No significant changes in students’ general attitudes towards science were found, however, students demonstrated positive changes towards science learning. Theatrical elements that seemed to be important in children’s recollection of the play were the narrative, props and stage effects, and characters. In the children’s memory, science was intertwined with the theatrical elements. Nonetheless, children could distinguish well between scientific facts and the fictive narrative.     

提高思想政治理论课实践教学实效性初探——以资源整合为视角

思想政治理论课作为对大学生进行思想政治教育的主渠道、主阵地,在大学生成长成才的过程中发挥着关键作用。而思想政治理论课实践教学的相对薄弱,是制约思想政治理论课充分发挥实效性的瓶颈。为此,如何提高实践教学的实效性就成了教育者普遍关注的焦点。     

河北省县域经济发展水平评价

依据近年统计资料选取了反映县域经济发展水平的8项指标，运用主成分分析法对河北省114个县的经济发展水平进行综合评价，同时结合当前河北省行政区划调整的实际，从整体上分析了河北省县域经济发展的现状和趋势．     

“遥体人情，悬想事势”－－文笔在《史记》中的运用

笔是相对史笔而言的。司马迁撰述《史记》，既用史笔也用笔。史笔旨在考信去伪，直言录实；笔旨在拟虚补罅，饰词运事。笔在《史记》中的运用相当广泛，大抵体现于五个方面，即猎奇述异、夸张渲染、拟话代言、议论抒情和细节描写。笔的运用有其必然性和必要性，它使《史记》在雄踞史坛崇高地位的同时，也迈进了多姿多彩、绚丽灿烂的学殿堂。     

Adaptive synchronization of chaotic Colpitts circuits against parameter mismatches and channel distortions

In this work, synchronization of chaotic Colpitts circuits, using adaptive controllers to combat circuit parameter mismatches and channel distortions, is studied by numerical simulations. Synchronization errors caused by different main circuit components are compared, and compensation for time-constant and time-varying circuit parameter mismatches is demonstrated. Different kinds of channel distortions, including time-constant and time-varying channel attenuation, Additive White Gaussian Noise (AWGN) are all investigated by numerical simulations and discussed. Simulation results indicated that the synchronization performance of chaotic Colpitts circuits can be greatly improved by applying adaptive controllers when parameter mismatches and channel attenuation are considered as time-constant or time-varying, but have no obvious enhancements regarding the effect on AWGN channel.     

小学生道德学习中教师的作用

小学生道德学习包括道德需要、价值分析、自我选择、道德实践、道德评价五个环节。教师必须整体把握五个环节之间的联系，从小学生道德潜能出发，为其提供道德实践机会，帮助其提高价值分析水平，引导其自主选择、自主反思和自主评价。