正、负和中性TiP_(10)团簇结构与电子性质的密度泛函研究

采用密度泛函理论的B3LYP方法研究了正、负和中性TiP10团簇的几何构型和电子结构.计算结果表明,中性TiP10团簇的基态构型为金属夹心结构,正、负离子团簇同样具有该基态稳定结构.通过对基态稳定结构的分子轨道分析表明,δ键对形成夹心结构起到重要作用.理论计算得到的中性TiP10团簇的垂直和绝热电离能分别为7.84和7.68eV,垂直和绝热电子亲和势分别为3.18和3.35eV

正、负和中性TiP_(10)团簇结构与电子性质的密度泛函研究

采用密度泛函理论的B3LYP方法研究了正、负和中性TiP10团簇的几何构型和电子结构.计算结果表明,中性TiP10团簇的基态构型为金属夹心结构,正、负离子团簇同样具有该基态稳定结构.通过对基态稳定结构的分子轨道分析表明,δ键对形成夹心结构起到重要作用.理论计算得到的中性TiP10团簇的垂直和绝热电离能分别为7.84和7.68eV,垂直和绝热电子亲和势分别为3.18和3.35eV

Structure and stability of binary transition-metal clusters (NbCo)(n) (n <= 5): A relativistic density-functional study

Equilibrium geometries and electronic properties of binary transition-metal clusters, (NbCo)(n) (n Nb-Co>Co-Co. As the binary cluster size increases, the Nb-Co bond may become stronger than the Nb-Nb bond in the inner niobium core, which results in a remarkable increment of the Nb-Nb bond length. Amongst these binary transition-metal clusters, the singlet (NbCo)(4) in T-d symmetry has a striking high stability due to the presence of the spherical aromaticity and electronic shell closure. The size dependence of the bond length and stability of the cluster has been explored. (C) 2005 American Institute of Physics

要勇敢面对一流本科教育这个世界性难题(笔谈)

本科教育是培养高层次人才的根本,也是培养科学创新型人才的起点。"双一流"建设背景下,建设一流本科教育日益成为社会共识,因为一流本科教育是一流大学之基。一流本科教育离不开高质量教学,高质量教学相信学生具有理性探究能力,只有坚持平等性、建构性和个性化原则,把能力培养作为教学的中心任务,才能进行有效的教学创新。合作学习是教学生态重建的抓手,也是提高教学质量、促进教学创新的一个重要向度。高质量教学需要可靠的保障机制,学生课程评估已成为高校教学质量保障体系的重要一环。但课程评估的主要目标是通过反馈以帮助教师改进教学,而不是对教师教学质量实施"监控"。一流本科教育最根本的标志是能够培养出一流人才,对"拔尖学生"的培养自然而然就成了人们关注的一个重点,学习投入、学习方法、学习情绪等"过程性指标"应成为关注的核心。一流人才的培养需要教学和科研发挥各自优势,协同育人。同时,一流本科教育依赖于一流的专业教育,一流的专业教育必须实现对传统专业教育模式的超越。教育部人文社会科学重点基地重大项目“中国特色的大学治理结构与质量保障机制建设研究”(项目编号:18JJD880005);教育部人文社会科学重点研究基地重大项目“经济新常态下的教育财政研究”(项目编号:16JJD880002)国家社科基金教育学一般项目“‘创新战略’背景下中国一流大学‘拔尖计划’本科生的深层学习研究”(BIA180169);国家社科基金“十三五”规划(教育类)一般课题“‘双一流’建设大学教学和科研协同育人机制研究”(项目编号:BIA180163)山东省高等教育改革与发展研究院重大委托项目“中国特色高等教育质量治理体系建构研究

第十八届美国理论与应用力学大会总结

1会议概况2018年6月5—9日,第18届美国理论与应用力学大会(18th U.S. National Congress of Theoretical and Applied Mechanics, USNCTAM2018)在美国芝加哥召开.本次大会由美国力学国家委员会和中国力学学会联合主办,旨在探讨和交流近四年世界范围内在理论和应用力学领域的基础研究、创新技术的最新进展,吸引了来自世界各地的近千名专家学

CCCCC pentadentate chelates with planar Möbius aromaticity and unique properties

本课题充分发挥了厦门大学多学科协同研究优势，通讯作者为夏海平教授（合成、表征）、刘刚教授（生物医学应用）和吕鑫教授（理论计算）。合成实验和结构表征由朱从青（第一作者，目前在麻省理工学院、2005年诺贝尔化学奖得主Richard Schrock教授课题组从事博士后研究）完成；生物医学应用由杨彩霞（共同第一作者）、林凎、杨宇惠、王晓勇合作完成；理论计算由朱军、王永恒、朱从青完成。美国NIH的陈小元教授参与了生物医学应用的讨论。该研究工作得到国家自然科学基金委、科技部项目的支持。The coordinating atoms in polydentate chelates are primarily heteroatoms. We present the first examples of pentadentate chelates with all binding atoms of the chelating agent being carbon atoms, denoted as CCCCC chelates. Having up to five metal-carbon bonds in the equatorial plane has not been previously observed in transition metal chemistry. Density functional theory calculations showed that the planar metallacycle has extended Craig-Möbius aromaticity arising from 12-center–12-electron dπ-pπ π-conjugation. These planar chelates have broad absorption in the ultraviolet-visible–near-infrared region and, thus, notable photothermal performance upon irradiation by an 808-nm laser, indicating that these chelates have potential applications in photothermal therapy. The combination of facile synthesis, high stability, and broad absorption of these complexes could make the polydentate carbon chain a novel building block in coordination chemistry.the National Basic Research Program of China (nos. 2012CB821600 and 2014CB744503) , the National Science Foundation of China (nos. 21332002, 81422023, 51273165, 21490573, and 21573179)

Stabilization of anti-aromatic and strained five-membered rings with a transition metal

1981年诺贝尔化学奖获得者、美国康奈尔大学RoaldHoffmann教授评价该项工作说：'The　paper is an excellent one--it's　quite a mazing that the parent Os　system,molecule 1,chooses to give the osmapentalyne'。德国化学家Uwe Rosenthal教授等在同期《自然—化学》杂志的《News and Views》栏目以《Breaking the rules》为题撰文评述了这一研究成果。全文地址：http://www.nature.com/nchem/journal/vaop/ncurrent/pdf/nchem.1702.pdfAnti-aromatic compounds, as well as small cyclic alkynes or carbynes, are particularly challenging synthetic goals. The combination of their destabilizing features hinders attempts to prepare molecules such as pentalyne, an 8π-electron anti-aromatic bicycle with extremely high ring strain. Here we describe the facile synthesis of osmapentalyne derivatives that are thermally viable, despite containing the smallest angles observed so far at a carbyne carbon. The compounds are characterized using X-ray crystallography, and their computed energies and magnetic properties reveal aromatic character. Hence, the incorporation of the osmium centre not only reduces the ring strain of the parent pentalyne, but also converts its Hückel anti-aromaticity into Craig-type Möbius aromaticity in the metallapentalynes. The concept of aromaticity is thus extended to five-membered rings containing a metal–carbon triple bond. Moreover, these metal–aromatic compounds exhibit unusual optical effects such as near-infrared photoluminescence with particularly large Stokes shifts, long lifetimes and aggregation enhancement

Correlations in Students' Learning of Quantitative Research Methods in University

研究技能已经成为当今公民素质中越来越重要的组成部分。今天的高等教育应当充分重视研究方法课程的教学,提高研究方法学习的质量与效果。诸多理论研究及实践经验都表明,学生在定量研究方法的学习上感到异常困难。基于这一现象,探讨大学生定量方法学习中的各种困难体验、经历类型及其与学生的早期数学学习情况、当下的定量方法课程的学习情况等之间的相关关系,就成为进行相应的教学设计与教学改进的重要理论基础。Research skills have become the important part of civil literacy today.Higher education today should pay more attention to the instruction of research method curriculum and try to enhance the quality and efficiency of students' learning in these courses.Many research results and practical experiences have shown that students usually experience many difficulties in their learning of quantitative methods.To improve the instruction of quantitative method courses,we should make some researches on the following topics: difficulties and experience types of students,and their relationship with students' earlier high school mathematics achievement and present university achievement of quantitative method research.This paper utilizes the quantitative research method to solve the above research problems

莱州湾海底有缆观测网自适应监控系统开发

文章为莱州湾海洋牧场海底观测网络开发了自适应可扩展的远程监控系统实现对海洋牧场环境的长期连续在线监测。针对观测网络的需求，文章建立了远程监控系统的控制模型，创新地设计出了针对海底观测网络数据海量、异构、多源和多维度等特点的通信机制以及通信协议，便于实现海底观测网络大量设备即插即用的动态管理算法，并改良了数据质量控制算法。莱州湾海洋牧场应用示范数据显示，数据丢包率低至1%，指令执行成功率达到98%，海底设备增删改时，系统可以在2 min内完成映射解析数据，同时，数据质量控制算法能有效剔除异常值，将错误率降低至0.000 81%。莱州湾海洋牧场成功应用的示范证明了该系统的性能和适用性，同时说明文章所提相关算法也可用于其他类似有自适应要求的系统中

吉林省蓝藻门两新种

描述了采自长白山永青电站的蓝藻门新植物灰白伪枝藻(Scytonema cineraceumC.L.Zhou et Xiao,sp.nov.),其原植体丛生,垫状,近半球形,灰褐色。蓝藻门新植物岩生蓝柄藻(Cy-anostylon rupestrisL.H.L櫣et Xiao,sp.nov.),采自吉林省集安市五女峰,植物团块为较柔软的胶质小皮壳状堆积体,棕黄色或棕红色