数字图书馆原型体系结构初探

本文主要介绍数字图书馆的概念、特征和体系结构及其由来和优点。同时 ,介绍建设数字图书馆所使用的相关标准、规范、工具和它的现实服务模式。     

大学图书馆规程的制订与思考——以《重庆大学图书馆规程》为例

“十四五”即将到来,图书馆需要在教育部颁布的《普通高等学校图书馆规程》的基础上,制订单馆的管理和服务流程规范,作为整个管理体制的纲,以《规程》为统领,梳理本馆的管理和服务模式,以利于图书馆治理能力的深化,在真正意义上提升图书馆效能,实现内涵式发展。文章以《重庆大学图书馆规程》为例,论述了整个编制过程和主要思想。     

图书馆Homepage的设计和制作

本文主要介绍建立图书馆Homepage 的目的和意义, 研讨设计中的关键技术, 阐述设计、制作 Homepage 的一般步骤, 并提供上海交通大学Homepage 的设计实例和经验。     

科技资源共享支撑体系的系统论探析

作为战略性资源的科技资源日益成为提高自主创新能力的基础条件和有力支撑,而优化科技资源配置的重要途径之一是实现科技资源共享,构建科技资源共享的支撑体系更是科技资源共享这一复杂系统工程的重要内容。本文从系统论的角度对科技资源进行了界定,构建了科技资源共享的政府、网络、资金和人才支撑体系框架,并以国家科技基础条件平台建设为例对科技资源共享支撑体系所具有的整体性、层次性、目的性和开放性系统特征进行分析。     

贵州大学在计算机科学系开设情报检索英语课

贵州大学在计算机科学系开设情报检索英语课为培养学生运用英语获取所需信息的能力，并通过阅读检索工具书的英文使用说明，而学会对检索工具的使用，贵州大学图书情报学系经学校领导和有关部门支持和批准，由图情系杨明华副教授和计算机科学系蒋学锋副教授合作，邀请新西...     

近五年我国高校图书馆科研知识图谱分析

以2007-2011年高校图书馆馆员在CSSCI来源期刊中发表的8,942篇文献和其包含的60 985条参考文献为研究对象,利用CiteSpaceⅡ对相关数据进行处理,分析了高校图书馆的科研产出、多产作者及合作团体、对高校图书馆科研具有重要影响的文献、研究热点,以知识图谱的方式,全面把握和梳理五年间我国高校图书馆的科研状况。     

Two decades of suspect evidence for adaptive molecular evolution—negative selection confounding positive-selection signals

There has been a large literature in the last two decades affirming adaptive DNA sequence evolution between species. The main lines of evidence are from (i) the McDonald-Kreitman (MK) test, which compares divergence and polymorphism data, and (ii) the phylogenetic analysis by maximum likelihood (PAML) test, which analyzes multispecies divergence data. Here, we apply these two tests concurrently to genomic data of Drosophila and Arabidopsis. To our surprise, the >100 genes identified by the two tests do not overlap beyond random expectation. Because the non-concordance could be due to low powers leading to high false negatives, we merge every 20–30 genes into a ‘supergene’. At the supergene level, the power of detection is large but the calls still do not overlap. We rule out methodological reasons for the non-concordance. In particular, extensive simulations fail to find scenarios whereby positive selection can only be detected by either MK or PAML, but not both. Since molecular evolution is governed by positive and negative selection concurrently, a fundamental assumption for estimating one of these (say, positive selection) is that the other is constant. However, in a broad survey of primates, birds, Drosophila and Arabidopsis, we found that negative selection rarely stays constant for long in evolution. As a consequence, the variation in negative selection is often misconstrued as a signal of positive selection. In conclusion, MK, PAML and any method that examines genomic sequence evolution has to explicitly address the variation in negative selection before estimating positive selection. In a companion study, we propose a possible path forward in two stages—first, by mapping out the changes in negative selection and then using this map to estimate positive selection. For now, the large literature on positive selection between species has to await reassessment.     

Recent progress in reactivity study and synthetic application of N-heterocyclic phosphorus hydrides

N-heterocyclic phosphines (NHPs) have recently emerged as a new group of promising catalysts for metal-free reductions, owing to their unique hydridic reactivity. The excellent hydricity of NHPs, which rivals or even exceeds those of many metal-based hydrides, is the result of hyperconjugative interactions between the lone-pair electrons on N atoms and the adjacent σ^*(P–H) orbital. Compared with the conventional protic reactivity of phosphines, this umpolung P–H reactivity leads to hydridic selectivity in NHP-mediated reductions. This reactivity has therefore found many applications in the catalytic reduction of polar unsaturated bonds and in the hydroboration of pyridines. This review summarizes recent progress in studies of the reactivity and synthetic applications of these phosphorus-based hydrides, with the aim of providing practical information to enable exploitation of their synthetically useful chemistry.     

网络环境下馆际互借的发展动向与问题

网络环境下的馆际互借服务是一种全新概念的服务,是实现资源共享的最佳方式。20世纪90年代以来,我国图书馆的馆际互借工作不断发展与完善。与此同时,也存在条块分割严重、经费投入短缺、标准化水平滞后等问题。这些问题的解决,既需要借鉴发达国家和地区的经验,也要研究我国馆际互借的发展状况与运行机制,促进馆际互借服务向更高层次发展。     

XrML在数字图书馆版权保护与利益平衡中的运用探析

本文对运用XrML于数字图书馆实现版权保护和利益平衡之目的进行了探讨。在分析XrML应用于版权管理的基本原理和概念的基础上,讨论了XrML的4个基本概念及其在数字图书馆中的运用以及运用XrML实现数字图书馆版权保护与利益平衡的设计指导思想。