Uncovering the secrets of hidden twists

<正>Twisted layered material junctions,and in particular twisted graphene interfaces,exhibit fascinating physical properties of diverse nature including unique structural,tribological,electronic,as well as heat and electron transport characteristics [1].These properties are intimately related to the moire superstructure formed at the twisted interface,which induces atomic lattice reconstruction patterns that balance between inter-layer registry optimization and intra-layer strain minimizati...     

新版新闻记者证开始全国统一换发

<正>国家新闻出版署日前下发《关于2019年全国统一换发新闻记者证的通知》,决定从2019年12月2日至2020年3月31日,统一换发全国新闻单位的新闻记者证。据了解,2019年版新闻记者证由国家新闻出版署统一印制,不收取任何费用,换发工作全部通过中国记者网的网络系统进行。换发期间,旧版新闻记者证继续有效使用。2020年3月31日后旧版将全部作废。通知明确,报纸出版单位、新闻性期刊出版单位、通讯社、广播电台、电视台、新闻电影制片厂、纳人新闻记者证核发范围的14家中央主要新闻网站等具有新闻采编资质的新闻单位,     

Crown-of-thorns starfish on the great barrier reef

During the 1960s and 1970s the bulk of the hard coral cover of reefs in the central region of Australia's Great Barrier Reef was killed as a result of population outbreaks of the coral-eating starfish, Acanthaster planci. Millions of starfish were involved. Renewed outbreaks have recently been noted on reefs where extensive recolonization has occurred since the mid-1960s, giving rise to concern that reefs in the region will be impoverished for long periods of time. The causes of the population outbreaks are unknown, but there is evidence of human involvement in triggering the population outbreaks.     

生鲜农产品供应链关系稳定性与其绩效的影响关系研究

为了探索和验证供应链关系稳定性与其绩效的影响机理,构建了供应链关系稳定性因素与供应链绩效的理论模型,并依托生鲜农产品供应链调研数据,运用结构方程模型方法对模型的拟合度和影响路径的显著性进行了检验。结果表明,信任与承诺对供应链财务绩效和运作绩效具有显著地正向影响效应;合作预期对供应链财务绩效、运作绩效和环境绩效具有强烈地正向影响作用;收益分配对供应链财务绩效、运作绩效具有显著地正向影响效应;关系资本对供应链运作绩效尤其是对环境绩效的改善起到显著地推动作用。     

ISDN and the great conversation

Abstract

This paper proposes that integrated services digital networks (ISDNs) can be used to educate groups of people by means of dialogue featuring an interactive exchange of textual, voice, graphic, and pictorial information. Participants need not meet in the same place at the same time. Instead, they may be remote and dispersed, and they can exchange information asynchronously if necessary. Benefits secured from using this approach include an increased flexibility in the delivery of educational services, reductions in travel and other costs and, importantly, the ability to engage a large number of people with different backgrounds in a knowledge‐gaining conversation without the necessity of their coming to campus. The article depicts a model seminar to illustrate the ways in which an ISDN conversation might be conducted.     

对创新链产业链资金链人才链“四链”融合发展的问题研究

推动创新链产业链资金链人才链（以下简称“四链”）深度融合对经济高质量发展的重要意义不言而喻,其本质是降低创新要素跨组织边界流动时遇到的各类壁垒,提升配置效率,更好发挥企业的科技创新主体作用,增强国家创新体系整体效能。文章在系统分析我国“四链”融合问题基础上,提出以下对策建议：（1）推动科技创新政策体系化布局和系统性落实;（2）探索建设“大科技中介机构”,构建符合创新规律的议事决策机制和市场化定价机制;（3）加快推进科技成果转化实施细则制定,明确责权利边界;（4）围绕产业链和创新链发展需求,前瞻性部署建设人才链;（5）强化财税政策对科技创新的支撑作用;（6）加强应用场景创新,助力提高国产新技术、新产品的市场接受度。     

不可回避的非存在问题

自柏拉图以来,著名的“非存在之谜”一直吸引着哲学家们为之绞尽脑汁。那么,非存在存在吗？到底有没有非存在对象呢？如果有非存在对象,那么它们是什么类型的对象呢？它们能被描述吗？有可能提供有关非存在对象的统一理论吗？这样的理论的解释力又如何呢？在当代哲学研究、尤其在心灵哲学意向性等问题的研究中,非存在问题是不可回避的。对象属性策略体现了非存在问题的传统哲学解决方案的现代拓展,语言策略体现了非存在问题的语言学研究的当代趋向,可能世界策略则向我们提供了一种更精细的逻辑论证思路。     

浅谈数学教师在教学中应具备的素质

本文从备课、教师的知识水平及其教育观念三个方面谈了数学教师应注意和具备的一些条件，目的是不断改进教学工作，努力提高教学质量和科研水平。