Enabling Mg metal anodes rechargeable in conventional electrolytes by fast ionic transport interphase     

Ruijing Lv  Xuze Guan  Jiahua Zhang  Yongyao Xia  Jiayan Luo 《国家科学评论(英文版)》2020,7(2):333

Rechargeable magnesium batteries have received extensive attention as the Mg anodes possess twice the volumetric capacity of their lithium counterparts and are dendrite-free. However, Mg anodes suffer from surface passivation film in most glyme-based conventional electrolytes, leading to irreversible plating/stripping behavior of Mg. Here we report a facile and safe method to obtain a modified Mg metal anode with a Sn-based artificial layer via ion-exchange and alloying reactions. In the artificial coating layer, Mg₂Sn alloy composites offer a channel for fast ion transport and insulating MgCl₂/SnCl₂ bestows the necessary potential gradient to prevent deposition on the surface. Significant improved ion conductivity of the solid electrolyte interfaces and decreased overpotential of Mg symmetric cells in Mg(TFSI)₂/DME electrolyte are obtained. The coated Mg anodes can sustain a stable plating/stripping process over 4000 cycles at a high current density of 6 mA cm⁻². This finding provides an avenue to facilitate fast ion diffusion kinetics of Mg metal anodes in conventional electrolytes.  相似文献   

Surface superconductivity in the type II Weyl semimetal TaIrTe4     

Ying Xing  Zhibin Shao  Jun Ge  Jiawei Luo  Jinhua Wang  Zengwei Zhu  Jun Liu  Yong Wang  Zhiying Zhao  Jiaqiang Yan  David Mandrus  Binghai Yan  Xiong-Jun Liu  Minghu Pan  Jian Wang 《国家科学评论(英文版)》2020,7(3):579

The search for unconventional superconductivity in Weyl semimetal materials is currently an exciting pursuit, since such superconducting phases could potentially be topologically non-trivial and host exotic Majorana modes. The layered material TaIrTe₄ is a newly predicted time-reversal invariant type II Weyl semimetal with the minimum number of Weyl points. Here, we report the discovery of surface superconductivity in Weyl semimetal TaIrTe₄. Our scanning tunneling microscopy/spectroscopy (STM/STS) visualizes Fermi arc surface states of TaIrTe₄ that are consistent with the previous angle-resolved photoemission spectroscopy results. By a systematic study based on STS at ultralow temperature, we observe uniform superconducting gaps on the sample surface. The superconductivity is further confirmed by electrical transport measurements at ultralow temperature, with an onset transition temperature (T_c) up to 1.54 K being observed. The normalized upper critical field h*(T/T_c) behavior and the stability of the superconductivity against the ferromagnet indicate that the discovered superconductivity is unconventional with the p-wave pairing. The systematic STS, and thickness- and angular-dependent transport measurements reveal that the detected superconductivity is quasi-1D and occurs in the surface states. The discovery of the surface superconductivity in TaIrTe₄ provides a new novel platform to explore topological superconductivity and Majorana modes.  相似文献   

用HornetQ实现异步消息传输     

关辉  李四海 《人天科学研究》2010,(12):33-34

在电子商务/电子政务的应用中,很多处理都需要以异步方式进行,JMS规范可以支持应用程序间消息的异步传递。详细论述了利用实现JMS规范的组件HornetQ来完成异步消息传输的过程。  相似文献   

对中国档案学理论原创性研究的思考   总被引：1，自引：2，他引：1  

管先海 《档案管理》2005,(1):17-18

本文就中国档案学理论原创性研究的内涵和意义、中国档案学理论原创性研究判断的理论标准和实践标准、中国档案学理论原创性研究不足的原因以及如何增强中国档案学理论研究的原创性问题谈了个人认识。  相似文献   

电子政务环境下档案资源整合与共享之瓶颈分析   总被引：1，自引：0，他引：1  

蒋冠  何振 《北京档案》2005,(3):33-34,36

一、档案信息资源管理瓶颈 1、档案资源的质量难以控制.从档案信息资源管理与档案信息服务的目标来说,要实现档案资源的整合与共享,档案部门面临着一个如何对所拥有的大量档案信息资源进行有机整合,建构高质量的档案信息资源库,以充分满足各种用户对档案资源质和量上的需求的问题.然而,这并非易事.一方面,就目前的情况来看,我国大部分公共档案馆馆藏结构十分单一,政府部门的文书档案占了很大的比例,而其他类型的档案少之又少,特别是某些特色档案更是缺乏.另一方面,档案资源与其他社会信息资源相比,有着机密性的特点,有一大部分档案因为涉及到国家集体的秘密而不能轻易地在网上公布,必须履行一定的手续,超过一定的期限才可以公之于众,而事实上,等到这些档案过了保密期之后,其所载信息往往已经过时滞后,无法满足公众的现时需要.因此,如何处理这一问题,尽量消除档案信息的供求矛盾,也是当前档案资源整合与共享中的一个难题.  相似文献   

可持续发展与民营院校图书馆     

覃冠 《图书馆论坛》2005,25(5):91-93

阐述了可持续发展的内涵，强调了科教兴国战略对可持续发展的重要作用。并在肯定民营院校及其图书馆的主流作用的基础上，针贬了其与可持续发展战略严重背离的种种现象，最后提出了相应的对策。  相似文献   

Children's motivation in elementary physical education: an expectancy-value model of achievement choice     

Xiang P  McBride R  Guan J  Solmon M 《Research quarterly for exercise and sport》2003,74(1):25-35

This study examined children's motivation in elementary physical education within an expectancy-value model developed by Eccles and her colleagues. Four hundred fourteen students in second and fourth grades completed questionnaires assessing their expectancy-related beliefs, subjective task values, and intention for future participation in physical education. Results indicated that expectancy-related beliefs and subjective task values were clearly distinguishable from one another across physical education and throwing. The two constructs were related to each other positively. Children's intention for future participation in physical education was positively associated with their subjective task values and/or expectancy-related beliefs. Younger children had higher motivation for learning in physical education than older children. Gender differences emerged and the findings provided empirical evidence supporting the validity of the expectancy-value model in elementary physical education.  相似文献   

档案职业伦理刍议     

蒋冠  洪海 《山西档案》2007,(2):14-17

职业伦理是一种特殊的社会意识形态,对于职业的生存与发展有着特殊的意义。档案职业的基本伦理原则包括求实保真原则、主动服务原则与尊重权益原则三个方面的内容。档案职业伦理建设是档案职业的一项重要的生存之策,文章就有关方面作了论述。  相似文献   

中国数据库产业的现状与发展   总被引：7，自引：0，他引：7  

关飞霞 《中国图书馆学报》1998,24(6)

ＣＬＡＳＳＮＵＭＢＥＲＧ２５８．９４当前,信息高速公路建设热潮席卷全球。信息高速公路即“国家信息基础设施”（ＮＩ）,包括信息设备、信息资源、通信网络和人才资源四个方面。通俗地讲,就是人、机、网、库四个要素。其中,信息资源（数据库是最主要的组成部分）是...  相似文献   

女子自行车运动训练原则与方法的研究     

关北光 《中国体育科技》1998,(4)

本文就河南女子自行车队的成功经验,对女子自行车运动的训练原则与方法进行了探讨。  相似文献