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.     

困境与选择:社会转型期的我国民办教育

近年来,民办教育中出现的一些事件风波,反映出一方面需要加强对民办学校的规范管理,以促使民办学校办学水平的提高;另一方面又需要进一步规范政府及教育行政部门的管理行为,探求有利于民办教育健康发展的体制、机制创新,为民办教育的持续发展创造一个公平、公正的生存空间.     

农民工子女免费义务教育的问题与对策

农民工子女理应享受免费义务教育,但在现实中却难以实现.流入地政府理应承担起农民工子女接受免费义务教育的重任,但受现实条件的制约,难以到位.为此,本文基于影响农民工子女享受免费义务教育的因素分析,提出相应的对策和建议.     

校园网常用网络安全技术

通过一些常用的网络安全技术来使得校园网更快,更健壮,更方便管理。本文列出了一些常用协议的作用及配置方法,如拓扑图、验证命令。     

三维散乱点的八叉树建模及程序实现

本文根据三维采样点的离散数据,用八叉树方法和与距离成反比加权法的数据插值方法重构地质体的三维模型,详细地论述了八叉树构模的程序算法,同时开发出基于VC 八叉树构模类,并嵌入电磁资料处理系统软件,为电磁资料处理的三维可视化提供了便利。     

大学生创业的软环境刍议

大学生创业已成为当今大学生的一种职业选择。针对大学生创业的环境影响因素进行分析,主要就软环境对大学生创业的影响加以探索,通过分析各种软环境因素的利与弊,探索出引导大学生顺利创业的正确方向和途径,从而提高创业的成功程度和比例。     

一体化地籍空间数据库建设的关键问题研究

由于城乡土地建设的发展需要,建立一个能够统一分类、统一调查、统一统计的城乡一体化信息系统便成为了当务之急。本文从建立城乡一体化地籍空间数据库的几个关键问题展开论述,分析了城乡一体化地籍的管理模式,提出了采用SDE来实现空间信息和非空间信息的统一管理,研究了新旧地类的转换和转换方法。     

商务智能在我国的发展现状、问题及其对策

商务智能(BI)的特点是使人们能从庞大而又繁杂的业务数据中提炼出有规律的商业信息,为商业决策提供依据。本文以BI技术为研究视角,分析其适合发展的行业、BI在国内的市场规模、国内外BI厂商,以及BI在我国的发展机遇与存在的问题,并针对现状、问题提出对策。     

节约型社会下的企业营销策略研究

目前,我国已经进入建设资源节约型、环境友好型社会时期。节约型社会的建设标志着企业的发展环境有了新的改变,对企业的营销策略提出了新的要求。因此,企业的营销策略应在观念、产品、渠道等方面有所改变以适应新的环境,形成企业新的竞争力。     

The global significance of biodiversity science in China: an overview

Biodiversity science in China has seen rapid growth over recent decades, ranging from baseline biodiversity studies to understanding the processes behind evolution across dynamic regions such as the Qinghai-Tibetan Plateau. We review research, including species catalogues; biodiversity monitoring; the origins, distributions, maintenance and threats to biodiversity; biodiversity-related ecosystem function and services; and species and ecosystems’ responses to global change. Next, we identify priority topics and offer suggestions and priorities for future biodiversity research in China. These priorities include (i) the ecology and biogeography of the Qinghai-Tibetan Plateau and surrounding mountains, and that of subtropical and tropical forests across China; (ii) marine and inland aquatic biodiversity; and (iii) effective conservation and management to identify and maintain synergies between biodiversity and socio-economic development to fulfil China''s vision for becoming an ecological civilization. In addition, we propose three future strategies: (i) translate advanced biodiversity science into practice for biodiversity conservation; (ii) strengthen capacity building and application of advanced technologies, including high-throughput sequencing, genomics and remote sensing; and (iii) strengthen and expand international collaborations. Based on the recent rapid progress of biodiversity research, China is well positioned to become a global leader in biodiversity research in the near future.