Construction of Metal Atomic-size Wires and Molecular Junctions and their Quantum Transport Investigation by STM-BJ Techniques

金属原子线和金属-分子-金属结（分子结）表现出特殊的量子输运性质，是纳电子学和分子电子学的重要研究内容。单分子结电导受到自身结构、金属与分子之间的接触构型和能级耦合及周围环境等因素的影响，其机理仍需进一步探讨，其中金属原子线和分子结的构建和电导测量是关键问题。STM裂结法（STM-BJ）是构建分子结的成功方法之一。然而，迄今为止的所有STM-BJ实验，无论是真空中、大气下，还是电化学中，都从相同金属材料的针尖和基底开始，导致缺乏普适性，如对一些软质金属或难以依靠机械撞击形成原子线的过渡金属的研究较为困难，由此也限制了以这些金属作为电极的分子结构建及其电导的系统研究，迫切需要寻找新的技术来获得突...Metal atomic-size wires and metal-molecule-metal junctions exhibit novel quantum transport properties, which are one of the focuses in nano-electronics and molecular electronics. The conductance of the single molecular junction depends not only on the intrinsic properties of the molecule, but also on the surrounding environment, contact geometries and energy-level alignment of the molecule-electro...学位：理学博士院系专业：化学化工学院化学系_物理化学(含化学物理)学号：1912005140308

Electrochemical Gating Single-Molecule Circuits with Parallel Paths

# These authors contributed equally to this work.电化学门控已成为一种可行且高效调节单分子电导的方法。在本研究中,我们证实了具有两个平行苯环的单分子电路中电子传输可以通过电化学门控控制。首先,我们利用STM-BJ技术以金为电极构筑了具有两条平行路径的单分子结。与单条路径的单分子结相比,两条路径的分子结由于具有增强性量子干涉效应,具有2.82倍的电导值。进一步地,我们利用电化学门控对具有两个平行苯环的单分结的电导进行调控,获得了333%·V-1调节比。结合DFT计算,发现在E=EF附近的V形透射系数谱图导致了实验观测的电导门控行为。本研究揭示了具有平行路径的单分子电路的电化学门控行为,并为设计高性能分子器件的分子材料提供了新的途径。通讯作者:周小顺E-mail:[email protected]:Xiao-ShunZhouE-mail:[email protected].浙江师范大学物理化学研究所,先进催化材料教育部重点实验室,浙江 金华 3210042.上海大学物理系,上海 2004441. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang, China2. Department of Physics, Shanghai University, Shanghai 200444, Chin

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

Does the Export Product Quality Affect the Export Volume?

已有文献在解释中国对外贸易增长原因时,对出口质量因素重视不够。本文应用指数理论和价格分解模型构建了可比较的中国行业出口质量指标,从出口产品质量的角度来解释各贸易伙伴国从中国进口贸易增长的原因,对中国典型行业的出口质量对出口量的影响进行了实证研究。结果显示:中国行业出口质量在被考察国家中整体偏低,位于下游水平;中国不同行业出口质量的发展趋势不同,其中食品与活畜行业、化学品行业和以材料分类的制品业等的出口质量呈现上升趋势;中国行业出口质量的提升是各国从中国进口贸易占比增长的重要原因,这在中低收入水平的进口国家中体现得尤为明显。因此,中国提出的外贸发展从规模扩张向质量效益提高转变的战略具有一定的可行性和必要性。Academic literature hasn't attached enough attention to the export quality when they explain trade growth in China.Based on index theory and discomposition model of price,this paper builds a comparable index of export quality in Chinese industries.Meanwhile,it researches empirically the effect of export quality on export volumn in industries.The conclusions include:in the horizontal,Chinese lower export quality among sample countries in industries;in the vertical,different trends of export quality in Chinese different industries,the tendency of food and live animals,chemicals and related products,manufactured goods classified chiefly by material in these industries on the rise;the promotion of export quality in Chinese industris resulting counterpart countries' growth of import trade percentage from China,especially to lowmiddle income countries.Hence,the strategic target of central government,which is the translating development pattern of foreign trade from the expand of scale to the improvement of quality,is feasible and necessary.2014年国家社科基金项目(14BJL058); 2012年教育部人文社科项目(12YC790104); 2014年中南财经政法大学博士生国际化联合培养项目资

Structure and Properties of Electrodeposited Sn-Co Alloy Electrodes asAnodeMaterial for Lithium-Ion Secondary Batteries

通讯作者, Te:l ( 86-592) 2181436, E-ma il: huang@l xm u. edu. cn[中文文摘]应用电沉积方法制备Sn-Co合金镀层. X-射线衍射和扫描电子显微镜分析表明, 该Sn-Co合金镀层为六方固溶体结构, 含Co量为20%的Sn-Co合金, 其沉积层呈现( 110) 择优取向. 表面微孔随沉积层Co 含量的增加而增多. 以Sn-Co 合金镀层作锂离子电极材料, 电化学性能测试表明, 其首次充电曲线表现出锡钴合金、锡及锡氧化物与锂合金化的多个反应综合特征, 随后的充电曲线趋于稳定, 呈现L-i Sn-Co 合金化反应特征; 具有择优取向和多孔结构的Sn-Co 合金电极材料的充放电性能较好, 首次库仑效率为63. 9%, 经过20 次充放电循环后, 其充电容量为461mAg /h, 库仑效率为99%.[英文文摘]The Sn-Co a lloy deposits were prepared by electroplating. The structure and electrochemical performance of the electroplated Sn-Co alloys have been investigated in detai.l Exper imenta l results show that the porous Sn-Co alloy film exhibits hexagonal solid solution, with Sn as the so lven,t Co as the so lute. The texture of the Sn-Co alloy coating exhib its (110) preferred orientation. Electrochemica l tests show that the porous Sn-Co alloy coat ing electrodes can deliver a discharge capacity of 643mAh /g in the first cycle. At the 20h cyc le the charge w as 461mAh /g. A t in itia l charge curve the irreversib le capac ity is probably associated to a comb ination of processes, w hich may include the reduct ion of small amount of tin dioxide and coba lt oxide on electrode surface,solvent decomposition and the formation of a passivating film on the e lectrode surface. The porous Sn-Co alloy electrodes can partly accommodate the volume expansion and phase transition during cycling, and would improve the cycle life of the electrode. They are also beneficial to diffusion of Li into /out of macroporousmaterials, and improve dischargeab ility /chargeability at charge discharge cycle.国家“973”项目(2002CB211804)资

Adsorption of Metal-Organic Complex Molecule on Au(111) Surface

[中文文摘]用STM对含氧桥的金属-有机配合物[Cu-2(μ-O)(dptap)_4 (NO3_)_2]分子在Au(111)表面的吸附行为进行了研究.STM结果表明,该分子同时存在非解离吸附和解离吸附,大部分分子在Au(111)面形成有规则的排列,少量分子发生解离吸附,并形成(3～(1/2)×"3～(1/2))R30°Cu原子吸附结构.探讨了两种吸附现象共存的起因。[英文文摘]The adsorption of metal-organic complex molecule ([Cu2(μ-O)(dptap)4(NO3)2], where dptap represents 2-(2-pyridylimino)-2H-1, 2, 4-thia-diazolo[2, 3-a] pyridine) on Au(111) surface is studied by STM. STM resluts show coexistence of undissociative and dissociative adsorption of the molecule. The former shows regular arrangements of the molecule, while the latter gives a (" 3 ×" 3 )R30°Cu adlayer structure. The possible origin of the coexistence of undissociative and dissociative adsorption is discussed.国家自然科学基金(20021002,20433040); 教育部博士点基金资助项目

Structure and Properties of Electrodeposited Sn-Co Alloy Electrodes as Anode Material for Lithium-Ion Secondary Batteries

应用电沉积方法制备Sn-Co合金镀层.X-射线衍射和扫描电子显微镜分析表明,该Sn-Co合金镀层为六方固溶体结构,含Co量为20%的Sn-Co合金,其沉积层呈现(110)择优取向.表面微孔随沉积层Co含量的增加而增多.以Sn-Co合金镀层作锂离子电极材料,电化学性能测试表明,其首次充电曲线表现出锡钴合金、锡及锡氧化物与锂合金化的多个反应综合特征,随后的充电曲线趋于稳定,呈现L i-Sn-Co合金化反应特征;具有择优取向和多孔结构的Sn-Co合金电极材料的充放电性能较好,首次库仑效率为63.9%,经过20次充放电循环后,其充电容量为461mAg/h,库仑效率为99%.The Sn-Co alloy deposits were prepared by electroplating.The structure and electrochemical performance of the electroplated Sn-Co alloys have been investigated in detail.Experimental results show that the porous Sn-Co alloy film exhibits hexagonal solid solution,with Sn as the solvent, Co as the solute.The texture of the Sn-Co alloy coating exhibits(110) preferred orientation.Electrochemical tests show that the porous Sn-Co alloy coating electrodes can deliver a discharge capacity of 643mAh/g in the first cycle.At the 20~(h) cycle the charge was 461mAh/g.At initial charge curve the irreversible capacity is probably associated to a combination of processes,which may include the reduction of small amount of tin dioxide and cobalt oxide on electrode surface,solvent decomposition and the formation of a passivating film on the electrode surface.The porous Sn-Co alloy electrodes can partly accommodate the volume expansion and phase transition during cycling,and would improve the cycle life of the electrode.They are also beneficial to diffusion of Li into /out of macroporous materials,and improve dischargeability/chargeability at charge discharge cycle.作者联系地址：厦门大学化学化工学院化学系,厦门大学化学化工学院化学系,厦门大学化学化工学院化学系,厦门大学化学化工学院化学系,厦门大学化学化工学院化学系,厦门大学化学化工学院化学系,厦门大学化学化工学院化学系 福建厦门361005,福建厦门361005,福建厦门361005,福建厦门361005,福建厦门361005,福建厦门361005,福建厦门361005Author's Address: *,ZHOU Shun-wei,KE Fu-sheng, YANG Fang-zu,FAN Xiao-yong,SUN Shi-gangDepartment of Chemistry,College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,Fujian,Chin