Flat-top and low-dispersion optical interleavers based on nested prism pair structure     

张娟 《上海大学学报(英文版)》2011,15(1):31-34

A novel flat-top and low-dispersion optical interleaver using ring cavities (RCs) in a Mach-Zehnder interferometer (MZI) is proposed. It is composed of eight mirrors and two nested prism pairs. Each prism and the two mirrors behave as a RC. Phase shift of RC is a periodic function of the frequency of the input light which acts as a phase dispersive mirror. The two phase shifts needed to achieve a flat-top spectral passband are provided by Fresnel reffectivities at the prism-air interface of the two RCs. The...  相似文献   

从社会成本与私人成本视角审视非公有制经济     

于喜繁  丛娟 《韩山师范学院学报》2011,32(4):42-47

非公有制经济的基本特征是私人成本较低,而社会成本较高。其私人成本较低,既是非公有制经济的生机活力的典型反映,也是它们基于自身的利益驱动将部分私人成本转嫁为社会成本的结果。社会成本较高,这是非公有制经济难以克服的根本缺陷。客观认识非公有制经济的成本高低和竞争优劣问题,应当从私人成本与社会成本相结合的视角,来审视非公有制经...  相似文献   

内蒙古西部方言对英语语音学习的影响     

刘娟  安利萍 《集宁师专学报》2011,33(2):68-70,74

该文依据语言迁移理论和方言发音特点,探讨了内蒙古西部方言对方言区学生英语语音学习的消极影响,并针对一些问题给出相应的解决策略,以期在教学中有的放矢,有目的地提高本地学生语音水平。  相似文献   

玩具数量对3～6岁幼儿分享行为的影响     

唐慧琳  严娟 《南京晓庄学院学报》2011,(5):90-93,124

为了用实验的方法探讨玩具数量对3～6岁幼儿分享行为的影响,选取了某幼儿园小、中、大班各30名幼儿,将各年龄班的幼儿随机分成人数相等的三组,三组进行游戏时玩具的数量不等,即分别为玩具数量多于、等于和少于小组人数。结果表明：小班、大班的幼儿都表现出当玩具数量少于人数时,幼儿做出分享行为的人数明显多于玩具数量等于和多于幼儿人数的情况。但中班幼儿面对不同数量玩具时的分享行为差异不显著。另外,当玩具数量等于人数时,表现出了明显的年级差异,大班幼儿做出分享行为的人数显著多于小班和中班幼儿。当玩具数量多于人数或少于人数时,不同年级幼儿的分享行为差异不显著。本研究的结论是：玩具数量是影响分享行为的因素之一,随着玩具数量的减少,幼儿的分享行为在增加。  相似文献   

基于IM的网络学习共同体构建及应用研究   总被引：2，自引：2，他引：0  

孙娟  熊才平  谢耀辉 《现代教育技术》2011,21(4):130-135

网络学习共同体能够促进学习者之间的沟通和交流,提高学习者的积极性和学习效果。文章在分析IM的教学功能、网络学习共同体现状及构成要素的基础上,提出了基于IM的网络学习共同体构建过程模式和基本模型,并通过QQ群进行网络教学实验,探讨了基于IM的网络学习共同体在实际教学中的应用。  相似文献   

学习共同体研究热点知识图谱分析     

李涵  王娟 《教育技术导刊》2020,19(7):271-274

为科学清晰地展现国内外学习共同体研究成果,以中国知网（CNKI）与科学引文数据库（WOS）为文献来源,运用 CiteSpace V 软件的关键词共现聚类分析、研究机构共现分析和关键词时区共现分析等方法绘制知识图谱。研究发现,国内外学习共同体研究前沿包括教师专业学习共同体、网络学习共同体以及实践共同体 3大主流方向。研究热点聚焦教师专业发展、项目教学、合作学习、情景学习、教学策略开发等理论。未来学习共同体将与深度学习、泛在学习、自组织等理论结合产生新的生长点,对教师专业发展和网络学习具有重要推动作用。  相似文献   

走近蓝牙技术     

白娟 《天津电大学报》2003,7(2):31-32,35

在无线通讯领域，蓝牙技术引起了越来越多的人的关注。本文介绍了蓝牙技术的起源及工作原理。阐述了它在实际生活中的应用。并对蓝牙技术的进一步发展提出展望。  相似文献   

Concept learning by pigeons: Matching-to-sample with trial-unique video picture stimuli     

Anthony A. Wright  Robert G. Cook  Jacquelyne J. Rivera  Stephen F. Sands  Juan D. Delius 《Learning & behavior》1988,16(4):436-444

Pigeons were trained to match-to-sample with several new methodologies: a large number of stimuli, computer-drawn color picture stimuli, responses monitored by a computer touch screen, stimuli presented horizontally from the floor, and grain reinforcement delivered onto the picture stimuli. Following acquisition, matching-to-sample concept learning was assessed by transfer to novel stimuli on the first exposure to pairs of novel stimuli. One group (trial-unique), trained with 152 different pictures presented once daily, showed excellent transfer (80% correct). Transfer and baseline performances were equivalent, indicating that the matching-to-sample concept had been learned. A second group (2-stimulus), trained with only two different pictures, showed no evidence of transfer. These results are discussed in terms of the effect of numbers of exemplars on previous failures to find concept learning in pigeons, and the implications of the positive finding from this experiment on abstract concept learning and evolutionary cognitive development.  相似文献   

Comprehension evaluation and regulation in learning from science texts     

Jose C. Otero  Juan M. Campanario 《科学教学研究杂志》1990,27(5):447-460

Metacognitive variables influence students' learning from science texts. This article deals with the comprehension monitoring abilities of secondary school science students, one of the areas of metacognition which has drawn considerable attention from researchers. The aims of the study are, in particular: (a) to know the extent to which comprehension is monitored by secondary science students as revealed by inconsistency detection in manipulated science texts, and (b) to identify the strategies used to regulate comprehension by the students who detect the inconsistencies. The results indicate that knowing that one understands or fails to understand science texts could be as important a problem as understanding proper. Besides, some incorrect regulatory strategies used by students who notice the inconsistencies in the texts are identified. These could also have an annoying influence in the regulatory behavior of students when studying regular science texts.  相似文献   

成长的失落--关注大学新生入学心理适应   总被引：2，自引：0，他引：2  

刘娟 《连云港师范高等专科学校学报》2005,(4):10-14

大学新生入学后，生活环境、生活条件、人际关系、学习方式与方法都不同了，这一系列的变化，逐渐使他们原有的习惯、心理结构与心理定势被打破，这时他们在心理上还残留有依赖性、理想化、盲目自信等心理特征。如此种种心理反应，都必须有一个适应期，期间他们感觉很突出的是成长过程的失落。  相似文献