The impact of two types of peer assessment on students' performance and satisfaction within a Wiki environment

The purpose of this study was to compare the effects of two peer assessment methods on university students' academic writing performance and their satisfaction with peer assessment. This study also examined the validity and reliability of student generated assessment scores. Two hundred and thirty-two predominantly undergraduate students were selected by convenience sampling during the fall semester of 2007. The results indicate that students in the experimental group demonstrated greater improvement in their writing than those in the comparison group, and the findings reveal that students in the experimental group exhibited higher levels of satisfaction with the peer assessment method both in peer assessment structure and peer feedback than those in the comparison group. Additionally, the findings indicate that the validity and reliability of student generated rating scores were extremely high. Using Wiki interactive software and providing an online collaborative learning environment to facilitate peer assessment added value to peer assessment.     

P2P流媒体系统概述

P2P技术的出现,使低成本的分布式服务成为可能。参与的用户既是服务的消费者,又是服务的提供者,这种特性尤其适合流媒体系统。P2P技术将集中的流媒体服务分散化,从而消除了传统系统的瓶颈,拓展了网络视频业务的应用范围。     

A peer mentoring social learning perspective of cross-cultural adjustment: The rapid-acculturation mateship program

One of the persisting challenges facing societies and organizations is to socially integrate sojourners, expatriates, including migrants into the host culture whilst leveraging reciprocal cross-cultural learning experiences. In a quasi-experimental field study, using an embedded unequal design, incoming international students’ (i-Students’) adjustment processes were investigated via a comprehensive 18/19-week peer mentoring social learning cross-cultural adjustment program. Forty-three local mentors were paired with 126 i-Student mentees, and 238 i-Students served as a control group. Quantitative and complementary qualitative data were collected from mentees, mentors, and controls at three time-points. Results showed effects in intercultural communication, cultural adjustment, life skills, and well-being domains. Mentors’ 360-degree synchronous evaluation of mentees showed increases in all skills measured. Post-program responses from participants confirmed the increase in communication and life skills, supporting the social learning hypothesis. Theoretical and practical implications are presented to assist individuals studying and/or working with their acculturation in foreign nations.     

同伴关系与幼儿的自我效能感发展

同伴关系为幼儿的自我效能感发展提供了丰富的信息来源,是影响学前期幼儿自我效能感发展的重要因素;与此同时,幼儿的自我效能感发展又会影响到幼儿同伴关系的确立和同伴之间的活动。     

蟋蟀基因组DNA提取方法

对直翅目蟋蟀总科部分种类酒精浸泡标本的基因组DNA进行了提取，样品经检测，谱带基本呈线形，无拖尾；OD(260／280nm)值86．11％在1．6—1．8之间。     

安全操作系统中的功能隔离机制

在分析现有操作系统安全机制的基础上,针对空间隔离技术的不足之处,提出了功能隔离的新思想。功能隔离可以提供更细致的隔离粒度,并可使不同类别的功能请求在相互隔离的执行域中执行,从而提高系统的可靠性与安全性。文中详细描述了功能隔离的定义,讨论了功能划分的方法和PFI、ASFI两种功能隔离机制及其关键实现技术。实验数据说明,采用功能隔离不会明显影响系统的效率。     

公共卫生危机治理中的博弈平衡——以重大传染病疫情防控的隔离措施为例

公共卫生危机治理过程中的一个重要问题是个人自由与公共利益的平衡,例如面对重大传染病引发的危及公共卫生安全事件而采取的强制隔离措施,体现了在特殊情况下,个人自由与公共利益、个人权利与政府权力的博弈平衡;而在这个过程中,个人负有积极配合隔离的义务,政府则负有传递真实信息以使个人充分享有知情权的责任。     

圈养大熊猫肠道致病菌的分离与初步鉴定

通过形态观察、选择培养、革兰氏染色和生理生化鉴定,对三只圈养亚成体大熊猫肠道致病菌进行了分离和初步鉴定.结果表明,分离到的19株菌分别属于大肠埃希氏菌(Escherichia coli)、沙门氏菌(Salmonella)、志贺杆菌(Shigella)、变形杆菌(Proteus)、克雷伯氏杆菌(Klebsiella)、葡萄球菌(Staphylococcus aureus)、耶尔森氏菌(Yersinia enterocolitica)等7个属,其中大肠埃希氏菌为优势菌.致病性试验结果显示,沙门氏菌、志贺杆菌、克雷伯氏杆菌、葡萄球菌和耶尔森氏菌对小白鼠有致病性.药敏试验结果表明,分离菌株对环丙沙星最敏感,高敏菌株占94.74%;其次是氧氟沙星和阿米沙星,高敏菌株分别占89.47%和42.11%;而对克林霉素、磺胺六甲氧嘧啶、罗红霉素、强力霉素等敏感性较差.该研究结果将为圈养大熊猫临床用药提供了科学参考依据.     

Prediction of vibrations induced by trains on line 8 of Beijing metro

This paper mainly discusses the problem of ground-borne vibrations due to the planned line 8 of Beijing metro which passes under the National Measurement Laboratory. A lot of vibration sensitive equipments are placed in the laboratory. It is therefore necessary to study the impact of vibrations induced by metro trains on sensitive equipments and important to propound a feasible vibration mitigation measure. Based or1 the coupled periodic finite element-boundary element （FE-BE） method, a 3D dynamic track-tunnel-soil interaction model for metro line 8 has been used to predict vibrations in the free field induced by trains running at variable speeds between 30 km/h and 80 km/h. Four types of track structures commonly used on the Beijing metro network have been considered： （1） high resilience direct fixation fasteners, （2） Vanguard fasteners, （3） a floating slab track and （4） a floating ladder track. For each of these track types, the vibration isolation efficiency has been compared. The results of the numerical study can be used to predict vibrations in nearby buildings and to decide upon effective vibration countermeasures.     

媒介技术变迁对儿童同伴关系的影响

媒介技术变迁为儿童的同伴关系重新设定框架。在印刷术大量应用前,儿童间同质性较高。印刷术的发明使得大规模公共教育成为可能,在学校里儿童获得了在各种规则下与同伴相处的能力,形成了新的互动惯习。电视的出现既导致儿童同伴关系的相对疏离,又促进了儿童同伴亚文化的形成。网络为儿童提供了获取同伴关系的新型方式,扩充了儿童与同伴的交流模式。手机的技术特征使得儿童在同伴关系中"永远在线",扩大了儿童的私人空间。