略谈19世纪美国黑人女子高等教育

立足于美国黑人的女子教育观,从政治、经济、历史学的角度,选取具有代表性的黑人女性作为研究范例,纵观了19世纪美国黑人女子高等教育的发展历程,揭示出美国黑人女性接受高等教育之路的艰辛,反映出19世纪美国男女和人种之间的不平等。     

A new look in representations for mathematics and science learning

Representations such as formal notations and diagrams routinely figure in students' learning of mathematics and science. However, in light of the extensive research on students' misunderstanding in these subject matters, it is reasonable to ask whether other kinds of representations might help students to reach better understandings. Indeed, a number of educators have developed innovative representations, typically on computers, that supposedly foster understanding through suggestive visual analogies and microworlds to manipulate. Evaluative research on these new look representations as we call them suggests that they indeed can help students to understand.In this review, we focus on exactlyhow these representations aid understanding. We propose that they do so by facilitating the learner's construction of explanations, justifications, predictions, and the like. These constructions require search in problem spaces, in the sense of Newell and Simon (1972). The representations in question reduce the cognitive load of such searches, clarify the structure of the problem spaces that need to be searched, and make certain moves in the problem spaces more immediate. We invoke Gentner's (1983) theory of structure mapping to explain how these advantages are attained. We also examine several characteristic pitfalls of representations in this style.     

基于虚拟现实的天体系统模型设计与应用

提出用3Ds max软件设计天体系统三维模型、用Cult 3D软件为模型添加旋转和移动等交互功能、在Flash软件中完成二维动态光影效果、在网页中通过JavaScript语言实现其交互的三维虚拟系统设计思想;以演示日食、月食的成因及天体运行的相关知识为例,设计创作太阳系三维虚拟场景,其中三维虚拟模型可与Flash对象交互,相关动态光影效果可同步显示;同时,介绍该实例可实现的各项教学功能与特点,探究虚拟现实技术引入教学的应用前景。     

机器翻译中设计的两个算法

在机器翻译的研究中,混合式方法是一种好方法。本文的工作主要有两部分：第一部分讨论直接散列检索算法;第二部分讨论近似机器翻译算法。