Probing nanoscale spatial distribution of plasmonically excited hot carriers

表面等离激元（SP）效应可产生远高于热平衡下费米能级能量的热电子-空穴对（热载流子），从而能够引发和促进相关的光电或者化学过程，为在纳米尺度上高效利用光能实现物质和能量转化提供了极为有效的手段，化学化工学院任斌教授课题组利用前期自主发展的电化学针尖增强拉曼光谱技术，通过调控电位开关SP热载流子催化的反应，实现了有效热载流子催化反应区域的纳米分辨成像，使反应区域在实空间的分布可视化。实验上获得了有效热载流子的输运距离，从而证明了能量越高的热载流子越需要在更短的输运距离范围内收集捕获。 该工作在任斌教授和王翔副教授的共同指导下完成。实验主要由化学化工学院已毕业博士生黄声超完成。理论计算主要由电子科学与技术学院的朱锦峰副教授和已毕业硕士生李察微完成。此外，化学化工学院已毕业硕士生赵庆庆、博后何玉韩和胡树等人也参与了部分研究与课题讨论。【Abstract】Surface plasmons (SPs) of metals enable the tight focusing and strong absorption of light to realize an efficient utilization of photons at nanoscale. In particular, the SP-generated hot carriers have emerged as a promising way to efficiently drive photochemical and photoelectric processes under moderate conditions. In situ measuring of the transport process and spatial distribution of hot carriers in real space is crucial to efficiently capture the hot carriers.Here, we use electrochemical tip-enhanced Raman spectroscopy (EC-TERS) to in situmonitor an SP-driven decarboxylation and resolve the spatial distribution of hot carriers with a nanometer spatial resolution. The transport distance of about 20 nm for the reactive hot carriers is obtained from the TERS imaging result. The hot carriers with a higher energy have a shorter transport distance. These conclusions can be guides for the design and arrangement of reactants and devices to efficiently make use of plasmonic hot carriers.The authors acknowledge the financial supports from MOST of China (2016YFA0200601), NSFC (21633005, 21790354, 21503181, 21711530704, U1830116), Natural Science Foundation of Fujian Province (2016J05046), China Postdoctoral Science Foundation (2017M622062) and the Fundamental Research Funds for the Central Universities (20720190010).本研究工作得到了国家自然科学基金委和科技部等的资助和支持

Relationship between Current Account Imbalances and Income in China:an Analysis Based on Intertemporal Consumption-smoothing Model and China’s Data

本文构造了一个开放经济下的跨期消费平滑模型,从动态的角度分析经常项目失衡、收入以及持久性收入之间的关系。同时运用格兰杰因果关系检验、Adf检验、协整关系检验对我国的经常项目差额、收入和持久性收入的关系进行实证研究。结果表明我国的经常项目差额、收入和持久性收入之间存在长期协整关系,收入的增加导致经常项目顺差增大或逆差减少,持久性收入的增加导致经常项目逆差增大或顺差减少。此外还运用收入和持久性收入对我国经常项目进行预测,效果较好。This paper establishes an intertemporal consumption-smoothing model in an open economy and studies the dynamic relationship between current account,income and permanent income in China by employing Granger-test,ADF-test and cointegration-test.This result indicates that there exists a long-run cointegration between current account,income and permanent income.The increase of income can increase current account surplus and the increase of permanent income can decrease current account surplus.Finally,this paper makes some suggestion according to our model and the empirical results.李晓峰主持的国家自然科学基金(项目号:70873098)的阶段性成

The Influence of the Reform of China's Exchange Rate System on the Adjustment Speed of Equilibrium Exchange Rate of RMB

本文首先运用行为均衡汇率模型(BEER)和协整理论,分别测算1994年~2006年和1994年~2005年第2季度的人民币均衡汇率水平,得到相关变量的协整关系式和误差修正模型。笔者通过比较发现:2005年7月21日起,我国实行的新汇率制度可以显著加快汇率回到均衡水平的速度,调整速度从过去每季度调整0.21增加到现在的每季度调整0.35,这说明我国这次汇率制度改革是十分成功的,可以显著加快人民币汇率回到均衡水平的步伐。This paper firstly applies BEER and cointegration theory to measure RMB equilibrium exchange rate of RMB in 1994—2006 and the second quarters of the years from 1994—2005 and gets the cointegration relationship of relevant variables and the error correction model.Comparing the results, the authors find that the reform of China's exchange rate system in July 21st 2005 increases adjustment rate from 0.21 to 0.35, which shows that this reform of China's exchange rate system is very successful and can accelerate the pace for the exchange rate of RMB to return to the equilibrium level

The Relationship between Gross Import and Export and Interest Rate Fluctuation in China——An Explanation Based on Transaction Cost

文章运用Adf检验、协整关系检验等对我国的出口额占进口额的比例(简称出口占进口比)和利率的关系进行实证检验,结果表明我国的出口占进口比和名义利率间存在着长期协整关系,并且是负相关关系。随后本文测算了每单位实际利率变动对出口占进口比的影响,结果表明大多数样本的影响值小于0,这个结果显然和传统理论的解释相异,为此文章建立了一个存在交易费用的两阶段开放经济模型解释我国的情况,最后提出一点启示。The paper makes an empirical test on the relationship between the ratio of export to import and interest rate in China by ADF test and co-integration test.The results show that there exists a long-run co-integration relation between the ratio of export to import and nominal interest rate and the two are negatively correlated.Then it measures the effect of real interest rate fluctuation per unit on the ration of export to import.The effects of the majority samples are less than 0 and this is significantly different from the traditional theoretical explanation.Therefore,the paper constructs a two-stage model of opening-up economy with transaction cost to demonstrate the situation in China.At the end,it provides some suggestion

tibetan basic character set supporting in openoffice.org

以开源项目OpenOffice.org为基础,针对藏文基本字符集在OpenOffice.org办公套件本地化的过程中出现的技术难点,根据藏文自身的特点结合OpenOffice.org中文本显示模块Icu的结构,解决了藏文小字符集在OpenOffice.org办公套件中显示、排序和转写等和文化与文字紧密相关的问题。该本地化软件可以跨Windows和Linux平台运行。中国中文信息学

Image local contrast enhancement method for improving perceptibility of image information

本发明是一种提高图像信息可感知度的图像局部对比度增强方法，保真图像局部信息的前提下尽量使图像中所有信息能被人眼清晰地感知到。保真图像局部信息是通过确保每一个像素与它周围一定范围内像素的灰度大小关系人眼感知不倒序来实现的。在此保真约束下，本发明从0开始一起同步拉大图像中所有灰度差不为0的相邻像素之间灰度值大小关系人眼可感知度，当部分相邻像素灰度大小关系人眼可感知度无法进一步拉大时，继续拉大其余相邻像素间灰度大小关系可感知度，直到所有相邻像素间灰度大小关系人眼可感知度都已经拉大到设定的可感知度阈值或者无法进一步拉大为止。本发明可用于增强各种原因导致的低对比度图像。</p

中国大陆主要变形系统/Major deformation systems in the Mainland of China[J]

地壳中的构造变形是已有岩石在地质应力作用下发生结构构造和空间位置变化的产物,因而是资源勘查开发和地质灾害防治不可忽视的重要地质现象.然而,地壳中的构造变形能否像岩石及岩石组合一样,也可以为一个地区的地质历史重建提供约束,在已有文献中没有系统的论述.文中针对这一问题,在系统研究了全球不同地球动力学环境构造变形特征的基础上,提出了变形系统的概念,将其定义为在一定区域范围内、同一地球动力学背景下同时形成的、具有不同几何学和运动学特征的各种构造变形的集合,并根据其产出的地球动力学环境,将其划分为11种类型.基于这一认识,在系统收集研究了中国大陆已有构造变形资料的基础上,简要介绍了中国大陆古生代以来的14个变形系统,探讨了中国大陆构造分区和构造演化的几个问题.根据与全球典型变形系统的对比,基于中国大陆古生代以来主要变形系统的时空分布,笔者提出:(1)中国东部新生代伸展变形系统的成因主要与澳大利亚板块向北运动有关;(2)中国东部海域可能隐伏有中生代晚期弧陆碰撞带;(3)中国东部白垩纪地球动力学环境可能类似于现今北美西部科迪勒拉型大陆边缘;(4)秦岭山脉南北两侧晚侏罗世至早白垩世挤压构造变形可能是蒙古鄂霍茨克造山带陆缘碰撞的远程响应;(5)敦煌-阿拉善地块在早古生代期间是中国大陆独立的第四大古陆块体;(6)西准噶尔和西天山北部属于哈萨克斯坦古板块北部增生边缘,准噶尔吐哈盆地基底及其以北的东准噶尔和阿尔泰山属于西伯利亚古板块古生代增生边缘;(7)小兴安岭和张广才岭东侧的原黑龙江群是大兴安岭地区西伯利亚古陆古生代增生边缘的向东延伸,不是侏罗纪增生杂岩或早古生代碰撞带的残片;(8)中国北方及邻区古生代至中生代期间经历了多次碰撞造山.中国大陆古生代以来变形系统的初步研究,表明变形系统的研究可以为大陆构造单元划分、构造演化和古地球动力学环境的重建提供重要的约束