受体分子侧基对非富勒烯受体和聚合物给体界面处激子解离速率的影响

以非富勒烯为受体的有机太阳能电池中,给体和受体分子可同时吸收可见光并各自产生光诱导的激子,这些激子的解离是决定太阳能电池效率的关键因素之一.因此,选取HXSC12分子为电子给体,6种具有不同侧基的1,8-萘酰亚胺小分子作为电子受体,利用Marcus公式和电子结构计算研究了给体和受体分子上激子在其构成界面上的解离过程,着重分析了受体分子侧基对两种激子的解离速率的影响.结果发现,给体和受体分子的吸收光频率互补,且对于效率较高的体系组合中两种分子上的激子解离速率基本具有相同量级,表明给体和受体在收集太阳能方面具有同等重要的作用.在受体中引入吸电子侧基后,可使得受体吸光强度增加,同时增加了给体-受体界面上激子解离的耦合强度和驱动力从而明显提高激子解离速率;而引入给电子侧基后,受体吸光强度明显降低,也降低了激子解离的耦合强度,导致激子解离速率降低.该计算结果与实验观测一致,可为制备高效的有机太阳能电池提供新思路.     

链间耦合对聚合物分子中激子形成的影响

从紧束缚模型出发,研究了聚合物分子中链间耦合对激子形成的影响.结果表明:光激发后耦合分子体系中形成的激子态有两种可能的分布:一种是激子在强耦合下仍主要局域在一条链中（称为链间定域激子）;另一种是激子在链间平均扩展（称为链间扩展激子）.通过计算链间耦合强度对这2种激子态的产生能和束缚能的影响,发现耦合体系中激发的电子－空穴更容易复合形成链间定域激子.另外,通过分析链间耦合强度对激子束缚能的影响,表明聚合物分子之间的耦合不利于激子形成,因此固态薄膜的光致发光效率要低于其溶液状态.     

准一维PtCl络合物的长程激子及其对静电场的响应

基于Baeriswyl Bishop模型 ,对PtCl络合物开链中的激子及其在静电场中的行为进行了数值研究 ,结果发现激子的光吸收峰在 1.5 5eV附近 ,这与Y .Wada等 (SynthMet,2 0 0 1,1～ 3:397.)最近的实验数据吻合得很好 .弱电场对激子没有明显影响 :当静电场超过临界值 15 0kV cm ,激子解离为电子型极化子和空穴型极化子 ,与共轭聚合物不同 ,极化和解离同时发生 ;电场增大至 35 0kV cm ,链体系发生结构相变并出现发光猝灭 .     

准一维有机半导体中极化子与激子碰撞产物分析

采用修正的SSH模型,描述基态非简并的有机共轭聚合物分子链中不同强度的电场下,一个负电极化子和一个三重态激子的碰撞过程。由于单重态激子和激发态极化子都可以通过辐射跃迁回到基态,显然,极化子和三重态激子的碰撞将有助于聚合物的发光。     

硫化铅量子点薄膜中基于量子隧穿的载流子输运机制

近年来，铅系量子点(如PbX,X=S,Se, Te)薄膜光物理性质的研究表明该材料在下一代柔性光电器件中存在潜在应用价值.理解量子点薄膜中载流子输运机制对于发展此类器件至关重要.利用超快瞬态吸收光谱技术，对PbS量子点薄膜中由于载流子输运导致的激子漂白峰位移做了系统性研究.结果发现在高带隙激发条件下，激子漂白峰随延时往低能方向移动，即发生红移.进一步通过分析光谱位移速率和幅值与温度的依赖关系，基于热激活隧穿输运模型揭示了PbS量子点薄膜中的载流子输运机制为电荷隧穿.     

纳米NiTiO3光声光谱研究

纳米钛酸镍粉末从可见光到近红外范围的光声光谱出现了三个强的吸收峰。４４５ｎｍ和５０５ｎｍ附近的吸收峰产生于自由激子和束缚激子的光跃迁，其变化趋势强烈地依赖于颗粒度大小，８４０ｎｍ处的吸收峰源于杂质的贡献     

碘代甲烷多光子激发色散荧光谱

采用色散荧光光谱方法,对308 nm强激光作用下CH3I分子的激发解离过程进行了实验研究.首先对所得色散荧光谱进行了归属,由此确定了主要的荧光产物粒子;依据荧光信号强度随入射激光能量的变化关系,研究了各碎片粒子的产生、激发及荧光跃迁过程,确定了对应的反应通道.所得结果对其他多原子分子的激发解离研究具有参考价值.     

光电功能型超分子聚合物的研究进展

超分子聚合物是重复单元经超分子弱键作用链接而形成的聚集体,是功能软物质中一种新的组织方式。文中基于众多超分子聚合物的分类,重点论述主链式光电功能型超分子聚合物(optoelectronic supramolecular poly-mer,OSP)在太阳能电池、有机电致光、电致变色等得到深入研究领域的应用进展;通过调控能量转移、电荷转移、载流子迁移率等可以实现OSP的白光、光电转换、电致变色等性质和相关器件,并使OSP日渐成为超分子化学与有机电子等学科交叉领域研究的新热点;最后展望了OSP的研究趋势。     

有序体系与无序体系中单重态激子的裂变过程及其磁场效应

利用单重态激子的裂变机制,被认为是提高有机光伏器件量子效率的一种可行途径.然而,在非晶态薄膜中有机分子的取向是杂乱的,能否在排列杂乱的分子之间发生有效的激子裂变过程,是制约这一方法的重要问题.本实验中,在室温下测量了红荧烯掺杂有机薄膜光致发光的磁场效应与光致发光的瞬态衰减,由此计算出了薄膜中红荧烯分子间激子裂变速率的磁场效应.基于Merrifield的唯象理论,研究了薄膜中分子排列有序与排列无序两种情况下激子裂变速率磁场效应的差异.将实验数据与理论曲线相对比,显示出掺杂薄膜中的激子裂变过程主要发生在排列无序的红荧烯分子间.这从实验上证明了在非晶态有机固体中可以发生有效的激子裂变过程.而激子裂变过程的速率主要与材料中的载流子迁移率有关.     

利用回音壁微腔系统克服量子点能级自然分裂

用一种全量子理论方法研究了一回音壁微腔-V型三能级量子点系统之间的耦合.量子点分别由基态、左圆极化激子态和右圆极化激子态构成,两简并回音壁腔模分别与左激子跃迁模和右激子跃迁模相耦合,其耦合率分别为gL和gR.在实空间里,我们推导了透射模与反射模的精确解,并得出其数值结果.结果显示了复合系统的耦合动力学特性;更重要的是,我们可以通过设计微腔得到合适的微腔反向散射率?,利用双模与量子点强耦合,就可以克服双激子能级精细结构的分裂(FSS).     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with