Use of Spectroscopic Representations in Student‐Generated Atomic Models

Abstract

The goal of this paper is to illustrate college students' levels of sophistication of their spectroscopic representations (SRs). For example, a photon is drawn as a wavy line, which might be used to enhance their atomic models (AMs). Study 1 was a quantitative study in which 70 students, enrolled in first semester general chemistry, drew or described their own model of the atom. Despite the fact that they had just completed a unit on atomic structure, only 30.6% of these students were classified as having a good understanding of the Bohr AM. Most of these students, 93.8%, incorporated SRs into their models. Conversely, only 41.2% of those who had a moderate AM understanding and only 5% of those with a poor AM understanding used SR in their AMs. Study 2 was a qualitative study in which 10 volunteers, enrolled in the same course but during a different semester, interacted with a multimedia instructional package and with a tutor. Interviews with two students were selected for in‐depth analyses. Each one enhanced their own AM by adding dynamic SR to their original AMs.     

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MHEG——多媒体和超媒体编码标准

随着信息多样化的发展,信息的表现形式向组合化发展,而单一媒体不具备将信息的内容与其表现特征在时间和空间上同步统一的能力,为此多媒体和超媒体技术应运而生。ＭＨＥＧ标准定义了多媒体／超媒体信息对象编码表示的最终形式,以及以该信息对象为单元在系统内部 或系统间进行的交互,它在多媒体／超媒体应用中,特别是交互式分布多媒体环境中将失常非常重要的角色。文中介绍了多媒体和超媒体编码标准ＭＨＥＧ的发展历史、范围、     

HJD04系列交换机三方通话和会议电话的实现

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基于Author Ware的多媒体课件的研究与实现

分析现有课件的优缺点,提出应用Author ware设计一套具有：登录验证、浏览、演示、测试、实验、帮助等六大功能,整个系统结构简单、功能强大、界面友好易于操作的《电子技术》多媒体课件方案。     

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工控系统中实时数据库关键技术研究与实现

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Potentials and challenges of peer-to-peer based content distribution

Multimedia content currently accounts for over three quarters of all Internet traffic. This increase in traffic volume and content availability derives from a paradigm shift from the traditional text and picture based Web, to more resource demanding audio and video content. A controversial driver for this development is content distribution systems based on peer-to-peer overlay networks. Flooding the Internet with often illegal content, these networks now pose challenges to all actors in the value chain. However, if viewed as surmountable challenges in an evolutionary path, peer-to-peer technology has the potential of increasing efficiency in content distribution and unleashing resources to form scalable and resilient overlay networks of unprecedented dimensions.

In this paper we examine the potentials and challenges of peer-to-peer technology in content distribution, and analyse how, and under which circumstances, peer-to-peer technology can be used to increase the efficiency of multimedia services. The paper provides an up-to-date overview of the development of peer-to-peer networks as well as describing the economics laws governing their use. To conclude the study, the paper analyses Skype, a well known telecommunications service utilising the peer-to-peer technology, as well as demonstrating the benefits of peer-to-peer based content distribution using empirical data from the Danish Broadcasting Corporation.