Direct observation of nodeless superconductivity and phonon modes in electron-doped copper oxide Sr1−xNdxCuO2

The microscopic understanding of high-temperature superconductivity in cuprates has been hindered by the apparent complexity of crystal structures in these materials. We used scanning tunneling microscopy and spectroscopy to study the electron-doped copper oxide compound Sr_1−xNd_xCuO₂, which has only bare cations separating the CuO₂ planes and thus the simplest infinite-layer structure of all cuprate superconductors. Tunneling conductance spectra of the major CuO₂ planes in the superconducting state revealed direct evidence for a nodeless pairing gap, regardless of variation of its magnitude with the local doping of trivalent neodymium. Furthermore, three distinct bosonic modes are observed as multiple peak-dip-hump features outside the superconducting gaps and their respective energies depend little on the spatially varying gaps. As well as the bosonic modes, with energies identical to those of the external, bending and stretching phonons of copper oxides, our findings reveal the origin of the bosonic modes in lattice vibrations rather than spin excitations.     

兴奋剂处罚取消比赛成绩“除非公平另有要求”探讨

通过对2022年北京冬奥会运动员瓦利耶娃案件的思考,对《世界反兴奋剂条例》（WADC）第10.10条规定的兴奋剂处罚取消比赛成绩例外之“除非公平另有要求”条款进行分析,指出该条款即公平原则例外情况在实际应用中存在的争议,即为保证体育运动的纯洁健康发展,对运动员实施取消所有比赛成绩时,必须注重对该例外情况的使用。但该条款的广泛性、模糊性以及赋予仲裁员无限制的自由裁量权,可能直接影响案件审理结果以及运动员的整个运动生涯。基于此,分析了公平原则例外情况在具体案件中的适用因素、存在不足以及相关完善建议。     

Students’ Ideas about How and Why Chemical Reactions Happen: Mapping the conceptual landscape

Research in science education has revealed that many students struggle to understand chemical reactions. Improving teaching and learning about chemical processes demands that we develop a clearer understanding of student reasoning in this area and of how this reasoning evolves with training in the domain. Thus, we have carried out a qualitative study to explore students reasoning about chemical causality and mechanism. Study participants included individuals at different educational levels, from college to graduate school. We identified diverse conceptual modes expressed by students when engaged in the analysis of different types of reactions. Main findings indicate that student reasoning about chemical reactions is influenced by the nature of the process. More advanced students tended to express conceptual modes that were more normative and had more explanatory power, but major conceptual difficulties persisted in their reasoning. The results of our study are relevant to educators interested in conceptual development, learning progressions, and assessment.     

色光引诱飞虫捕灭器

1 研究目的 本飞虫捕灭器是利用灯具的色光为光源,将各种飞虫引诱到光源周围并将飞虫一网打尽. 2 研究背景 目前家庭使用的各种蚊香,灭蚊剂,电蚊拍等或造成大气污染或造成噪声污染,长期使用会引起人的呼吸道感染,危害人体生理或心理健康;田间使用的各种农药在庄稼上有一定的残留,污染环境,对人体的健康也有一定的影响.为了寻找一种实效,节能,环保的飞虫捕捉方法,研制了色光引诱飞虫捕灭器.     

编后记:科技期刊不应忽视的编辑手段

编后记在期刊编辑工作中有着重要的作用,表现为:通过编后记介绍报道重点,起到导读作用;抒写编辑意愿,加强编读交流;阐明选题趋向,吸引作者投稿;增强可读性,营造轻松氛围;折射编辑风格,记录办刊历程.编后记是科技期刊不能忽视的编辑手段,但我国科技期刊很少有编后记,应该考虑有选择地利用编后记.     

论图书馆人的权利意识

图书馆精神有3个层次,演生出两种图书馆权利:社会立场和馆员立场的图书馆权利。两种图书馆权利是统一的,即以保障公民信息权利为目标维护图书馆人的职业权利。本文侧重讨论了图书馆人的职业权利问题,通过两个案例说明维护图书馆职业权利的必要性,讨论了图书馆员、图书馆学理论界和图书馆管理部门各方在维护图书馆职业权利方面面临的问题。     

数字参考咨询服务的质量控制研究

以全面质量管理理论为认识基础,系统分析了影响数字参考咨询服务质量的关键要素与关键过程,并提出相应的质量控制措施。指出对这些关键要素的控制,是缩小服务质量差距、提高服务质量的核心;对服务的关键过程进行控制,是提高服务质量的关键。     

新型图书馆用条码识别设备研究

条码技术在图书馆已得到广泛的应用，传统的条码识别设备成本高，功能单一。本文提出一种新的图书馆用条码识别设备，通过普通的视频摄像头结合图像处理和识别算法实现条码自动识别，具有成本低、可扩展性高的优点。实验结果和应用分析表明该设备是一个非常有前景的图书馆自动化设备。     

开源软件在国内图书馆的应用研究

从开源软件在国外图书馆的应用研究概述入手,论述开源软件对国内图书馆建设产生的积极影响,指出开源软件在国内图书馆使用中存在的风险,最后对国内图书馆使用开源软件提出建议。     

数字化手持:未来主流的媒体终端接受模式

本文回顾了大众媒体接受终端发展历史,在此基础上提出了数字化手持是未来主流的媒体接受终端模式.