有趣的"飞机怕鸟"

你相信吗?飞鸟与高速航行的飞机相撞,就象子弹一样击中机身,可使飞机坠毁。国际上已经为这类事故起了一个形象的名字叫“鸟撞”。据报载:1962年11月,赫赫有名的“子爵号”飞机正在美国马里兰州伊利奥特市上空平衡地飞行,突     

美国高校学术科研信息公开的原则、标准及路径

科学研究是高校自治中的重要内容,也是自治程度最高的领域。同政府信息公开相比,学术科研信息适用推定公开原则的范围较窄,其是否公开涉及的因素更多,公开范围的确定和划分更加复杂。从学术科研信息公开范围来看,美国大学信息公开制度主要从信息公开时间节点、信息种类、所涉利益的轻重缓急等多个维度出发,制定了一套易于实施操作的分类划分标准,很好的处理了学术自治与信息公开之间的矛盾,在保证信息公开的同时维护了相关利益者的权益。通过案例分析,对美国学术科研信息公开制度进行了深入探讨,对信息分类方法、标准和原则等进行了讨论,为我国学术科研信息公开提供有益经验。     

双机容错在医院信息系统安全中的应用

双机容错是计算机应用系统稳定、可靠、有效、持续运行的重要保证;为确保医院信息系统的正常运转,防止数据丢失,服务器采用双机容错是必要的。     

Use of place information for improved event tracking

The main purpose of topic detection and tracking (TDT) is to detect, group, and organize newspaper articles reporting on the same event. Since an event is a reported occurrence at a specific time and place and the unavoidable consequences, TDT can benefit from an explicit use of time and place information. In this work, we focused on place information, using time information as in the previous research. News articles were analyzed for their characteristics of place information, and a new topic tracking method was proposed to incorporate the analysis results on place information. Experiments show that appropriate use of place information extracted automatically from news articles indeed helps event tracking that identify news articles reporting on the same events.     

虚拟R＆D网络组织边界分析

虚拟R＆D网络组织边界问题是理解当代科学技术活动演化的重要问题.结合组织网络化发展的趋势,分析了组织边界的内涵,并在此基础上讨论了如何界定虚拟R＆D网络组织的边界,还对决定虚拟R＆D组织边界的重要因素做了进一步的研究,以期深化对这一问题的理解。     

企业盈余管理存在原因的理论分析

运用契约理论和信息不对称理论探讨了盈余管理产生的本质原因,分析了“契约摩擦”与“沟通阻滞”造成盈余管理现象的内在机理。契约摩擦”与“沟通阻滞”对盈余管理的影响并不是截然分开的,现实中的盈余管理现象往往是两种因素共同作用的结果。     

量化数字人文综述

数字人文对多样化研究内容、语言和学者的包容性,使其在近20年得到突飞猛进的壮大,并逐渐涉及人文学、社会学、计算机科学等多个领域。然而,包容的“大帐篷”不仅在一定程度上限制了对数字人文具体学科内容、科研范畴、学者群体和学科历史的理解,也使得学科成长和拓展缺少客观数据和理论的支持,从而无法健康且可持续地发展。文章回顾前人对数字人文所做的学科研究,重点集中在使用计量和统计等方法来揭示数字人文的知识结构、内容演变、合作模式和学者背景等工作上,以期帮助学界从量化的角度认识数字人文的形成、发展和前景。     

基于用户利用数据的高校图书馆资源共享服务趋势与优化策略探究

在多元便捷的信息环境下,图书馆资源共享服务当前面临着激烈的竞争,需转变服务思路。通过采集样本图书馆在CALIS平台上5年的用户数据,从业务趋势、用户结构分布、平台使用习惯、对比分析、定位分析多个维度,解析了用户群体特征。并提出了多项服务质量优化举措以及分层式宣传策略,进而为资源共享服务的发展提供参考。     

中国图书馆市场分析及拓展策略

国内的图书馆主要分为四种类型:高校图书馆、公共图书馆、中小学图书馆、科研单位及企事业单位资料室.据资料显示,目前全国共有公共图书馆2736个(引自《"十五"时期我国社会事业发展的基本情况和特点》一文),普通高校图书馆1792个(根据《中国教育事业发展状况》分析得出),这两个数据是比较准确的,同时这也是国内图书馆市场的主要组成部分.     

Genetic analysis of fruit shape traits at different maturation stages in sponge gourd

The fruit shape is important quantitative trait closely related to the fruit quality. However, the genetic model of fruit shapes has not been proposed. Therefore, in the present study, analysis of genetic effects for fruit shape traits （fruit length and fruit perimeter） in sponge gourd was conducted by employing a developmental genetic model including fruit direct effects and maternal effects. Analysis approaches of unconditional and conditional variances were applied to evaluate the genetic behavior of fruit shape traits at economical and physiological maturation times. The results of variance analysis indicated that fruit length and fruit perimeter were simultaneously affected by fruit direct genetic effects and maternal effects. Fruit direct genetic effects were relatively more important for fruit shape traits at whole developmental period. The gene expression was most active at the economical maturation stage （1-12 d after flowering） for two shape traits, and the activation of gene was mostly due to direct dominance effects at physiological maturation stage （13-60 datter flowering）. The coefficients due to different genetic effects, as well as the phenotypic correlation coefficients, varied significantly between fruit shape traits themselves at various maturation stages. The results showed that it was relatively easy to improve fruit shape traits for industrial purpose by carefully selecting the parents at economical maturation stage instead of that at physiological maturation stage.