点位控制加工中刀具路径的优化设计

本文阐述了在CAD／CAM集成系统中孔加工刀具路径的优化问题,利用图论中“旅行商问题”的数学模型,对加工中心上多孔加工刀具路径进行了优化设计。     

农业绿色GDP测算方法初探和实证

农业常规GDP已不能反映农业对经济、环境、社会的真实贡献.农业绿色GDP应该既反映农业作为生态系统提供的正外部性,又反映农业生产中资源消耗引致的负外部性.本文运用绿色GDP和生态服务价值的相关理论,对农业绿色GDP测算方法进行优化和构建,提出核算公式,并以中部农业大省湖北省为例,进行实证分析.     

Modeling the relative efficiency of national innovation systems

Although a large amount of past research has theorized about the character of national innovation systems (NISs), there has been limited process-oriented empirical investigation of this matter, possibly for methodological reasons. In this paper, we first propose a relational network data envelopment analysis (DEA) model for measuring the innovation efficiency of the NIS by decomposing the innovation process into a network with a two-stage innovation production framework, an upstream knowledge production process (KPP) and a downstream knowledge commercialization process (KCP). Although the concept of innovation efficiency is a simplification of the innovation process, it may be a useful tool for guiding policy decisions. We subsequently use a second-step partial least squares regression (PLSR) to examine the effects of policy-based institutional environment on innovation efficiency, considering statistical problems such as multicollinearity, small datasets and a small number of distribution assumptions. The hybrid two-step analytical procedure is used to consider 22 OECD (Organisation for Economic Co-operation and Development) countries. A significant rank difference, which indicates a non-coordinated relationship between upstream R&D (research and development) efficiency and downstream commercialization efficiency, is identified for most countries. The evidence also indicates that the overall innovation efficiency of an NIS is mainly subject to downstream commercial efficiency performance and that improving commercial efficiency should thus be a primary consideration in future innovation policy-making in most OECD countries. Finally, the results obtained using PLSR show that the various factors chosen to represent the embedded policy-based institutional environment have a significant influence on the efficiency performance of the two individual component processes, confirming the impact of public policy interventions undertaken by the government on the innovation performance of NISs. Based on these key findings, some country-specific and process-specific innovation policies have been suggested.     

国外教育资源元数据标准比较研究

介绍4种国外主要的教育资源元数据标准:IEEE LOM、DCEd、GEM、ADL/SCORM;从结构体系、元素繁简、描述能力、扩展规则、互操作性等多方面对它们进行比较、分析,指出在元数据规范创建过程中,需要注意尽量借鉴已有的高质量之数据标准;元素的设置应宜简不宜繁;元数据标准要具备良好的扩展能力和互操性等。     

大中专院校学生心理社团发展模式的探索

大中专院校招生规模的不断扩大,生源质量明显下降,学习压力与社会竞争带来的学生心理冲突,严重影响了学生的专业学习和思想发展,学校心理健康教育面临了前所未有的挑战。本文从分析大中专院校学生心理社团发展的必要性、目标与特点入手,提出构建以学生为主体的"朋辈心理辅导教师心理咨询校内外心理拓展训练"相结合的发展模式,为解决当前学校从事心育的合格专业人才奇缺的问题,找到了一条有效的途径。这种心育模式是学校传统心育的良好补充,也将成为今后大中专院校心育的主流模式。     

科技文献主题标引应特别注意的几个问题

从科技文献的特点出发，结合标引实践，强调了科技文献主题标引应注意的几个问题。     

关于建立中文图书编目工作规范档刍议

本文简述编目规范的作用、依据，着重论述名称规范、丛编规范和多级多卷书规范的做法。并述及自动实现规范控制的前景。     

农户分化、代际差异对宅基地退出意愿的影响——基于宅基地价值认知的中介效应分析

自愿性原则是当前宅基地退出制度的重要实施基础,引导农户自愿有偿退出宅基地对于实现耕地保护目标、推动城镇化进程具有重要意义。本文以武汉城市圈483个实地调查样本为例,通过考察农户分化与宅基地退出意愿的关系,以及宅基地价值认知、代际差异在两者关系中的作用,探究农户分化对宅基地退出意愿的作用机制。研究结果显示：①农户分化对宅基地退出意愿的影响路径包括直接正向影响和通过宅基地价值认知产生的间接正向影响,直接效应占总效应48.54%,间接效应占总效应的51.46%;②代际差异对宅基地价值认知在农户分化与宅基地退出意愿间所扮演的中介作用起到了调节效应,新生代农户受到的宅基地价值认知中介作用更加强烈和显著,而老一代农户的宅基地价值认知中介作用被削弱并趋于不明显。因此,提升农户宅基地退出意愿应从提升农户非农就业水平与引导农户形成合理的宅基地价值认知两个方面着手,并对不同代际农户制定针对性的政策措施以推进宅基地有偿退出。