基于J2EE和Flex技术图形化群组讨论

J2EE+Flex模式应用开发是当前的网络应用发展趋势,同时图形化聊天工具也是当前市场上的一块功能空白。基于J2EE+Flex模式,依靠Flex强大的GUI功能、AMF对J2EE兼容的框架的便捷通信服务,以及高效的XML编、解操作来实现B/S模式的图形化群组讨论的功能。     

“You have to know the past to (blog) the present:” Using an Educational Blog to Engage Students in U.S. History

In this study the authors investigate whether a whole-class educational blog could facilitate culturally relevant instruction and authentic intellectual work in U.S. history. Qualitative data were collected and analyzed that included student comments posted to an educational blog, classroom observations, and follow-up interviews. Based on the analysis, the authors determined four major findings: (a) Students were able to engage in historical analysis while working in the blog environment when it was focused on a single source and included a hard scaffold; (b) when students situated the activities in relevant cultural experiences, they were able to better use their prior knowledge;(c) a variety of affordances related to blogging encouraged and supported students as they completed their work; and (d) the blogging activities were constrained by the limits of students’ literacy and historical skills, and the limits of technology.     

2-甲基咪唑合成原液蒸发精馏分离

简述了2-甲基咪唑合成分离方法,指出了原工艺中存在的问题,提出2-甲基咪唑合成原液蒸发精馏新分离方法。通过实验得到最佳的工艺条件：原液剩余量约占取样量40%;填料柱高度为0.5 m;回流比为8∶1;冷凝液的温度为10°C以下。在该条件下分离2-甲基咪唑的效果最佳,收率约为80.1%,且可回收4.5%的白色固体（即乙醛合氨）。     

大学英语“1+2”教学模式研究与实践

在输入假说及建构主义理论指导下,依据学生个性化发展需求,利用现代信息技术,构建了大学英语"1+2"教学模式,即"1个体系"(大学英语分级教学课程体系),"2个平台"(自主学习网络平台和基于语料库的教学平台)。该模式在发挥传统课堂教学优势的基础上,注重发挥现代信息技术在教学中的积极作用,利用"英语在线"网络平台和语料库平台满足不同层次学习者的需要,促进学生个性化学习方法的形成和学生自主学习能力的发展,培养学生英语综合应用能力。     

Adolescent drug use and the deterrent effect of school-imposed penalties

Estimates of the effect of school-imposed penalties for drug use on a student's consumption of marijuana are biased if both are determined by unobservable school or individual attributes. Reverse causality is also a potential challenge to retrieving estimates of the causal relationship, as the severity of school sanctions may simply reflect the need for more-severe sanctions. Using the National Longitudinal Study of Adolescent Health, I offer an instrumental-variables approach to retrieving an estimate of the causal response of marijuana use to sanctions and thereby demonstrate the efficacy of school-imposed penalties as a deterrent to adolescent drug use. This suggests that school sanctions may have important long-run benefits.     

混沌学理论视角下的二语词汇习得初探

将混沌学理论应用于二语词汇习得研究,扩展了二语词汇习得的研究空间。通过分析混沌学理论与二语词汇习得的相关性,表明混沌学理论对二语词汇习得具有重要的应用价值和启示作用。二语习得过程中不仅要对二语词汇进行精细加工、反复练习,把握整体、增加维度,而且应重视母语的作用以及二语词汇的文化内涵。     

基于建筑节能专业人才培养模式的探讨

本文通过对湖南省若干建筑企业进行调查并对调查结果进行分析,调查组提出了"2+1"全日制建筑节能专业人才培养模式、企业节能施工人员短期培训模式、全日制建筑节能专业人才培养模式为当前建筑节能人才的培养献计献策,并对其分析了每种培训模式的框架和优点。     

锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2的研究概况

本文综述了近几年来锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2的研究进展,重点讨论了LiNi1/3Co1/3Mn1/3O2正极材料的结构,制备方法和改性研究状况。     

P2P技术在图书馆联盟云服务中的应用研究

P2P技术的数据流量在当代因特网传输中具有重要地位,我们提出基于云服务的P2P资源离线下载模式,由应用服务器负责P2P下载,用户通过下载中心把完成下载的资源传输到本地。在P2P下载期间,用户不必运行P2P客户端程序,也不必开启本地计算机。这一模式能减少重复下载热点资源对Intranet公共出口带宽的堵塞,减少漫长等待稀缺资源的过程困扰下载用户,避免热点资源的网络流量突增导致其他程序性能受到影响,解决了传输瓶颈,提高联盟用户下载资源的速度,节省了成本。     

二进制振幅键控频谱分析的Simulink仿真

针对数字调制系统中的二进制振幅键控的频谱公式多而且难理解和学生学习枯燥等问题,提出用Simulink仿真,无需大量书写程序,而只需要通过简单直观的鼠标操作,就可构造出复杂的系统,可以激发学生的学习兴趣和有效地节省课时,收到良好的学习效果．