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 .     

电场对量子阱中激子的影响

利用变分方法计算了GaAs/Al_2Ga_(1-x)As量子阱中激子的束缚能,分析了电场、势阱宽度对激子束缚能的影响。采用明显不可分离的试探波函数,并考虑了电场对势阱中载流子几率分布的影响,计算了重空穴激子和轻空穴激子吸收峰位置随电场变化,结果与实验值符合得较好。     

单层β12-硼烯双光子性质的理论研究

利用五带紧束缚理论计算了均匀模型、反演对称模型、反演非对称模型三种不同模型的单层β₁₂-硼烯的电子能带结构，利用光子-电子相互作用的二阶微扰理论计算了单层β₁₂-硼烯在可见光到近红外波段的双光子吸收谱，揭示了外加电场对X、K、M、Λ四个能带接触点附近电子能带和双光子吸收峰的调制作用.结果表明外加电场会带来简并能带的分裂，增强外加电场会使得双光子吸收峰发生蓝移且峰值被抑制；仅在反演非对称模型中M点附近施加正向电场且电场的能量在1.5～2.0 eV范围内时，因为双光子共振跃迁而出现吸收峰增强.     

反式聚乙炔的高激发态极化子

在Su-Schrieffer-Heeger（SSH）模型基础上,计入长程电子关联的影响,研究反式聚乙炔分子链中的高激发态极化子的稳态性质.与一般的低激发态极化子比较,高激发态极化子的晶格畸变更宽更深,能隙中的两个局域几乎重合,除了在1.35 eV附近的peirls吸收峰,高激发态极化子仅有一个约0.65 eV的低能吸收峰,而普通极化子有2个低能吸收峰,一个在0.175 eV附近,一个在0.85 eV附近.这些区别为区分两类极化子提供判据.     

光诱致聚乙炔激子的产生和演化

在Su—Schrieffer—Heeger（SSH）哈密顿基础上引进弱电子关联,对反式聚乙炔链中单激子的产生和演化过程实施了分子动力学模拟．结果表明,弱关联的引入显著加快了激子的产生和演化,激子形成的时间由零关联的104fs缩短为48fs;弱关联未能使呼吸子的振荡周期发生显著改变,但呼吸子振荡成为等振幅恒频率模式．聚乙炔光诱致吸收试验中的瞬时高频吸收峰解释为呼吸子吸收．     

CuCl团簇组装薄膜的荧光红移现象

利用气相蒸发技术成功的制备了两个ＣｕＣｌ团簇薄膜样品．ＣｕＣｌ团簇被沉积到单晶Ｓｉ和石英衬底上,然后覆盖一层ＮａＣｌ以防氧化．通过透射电镜和选区衍射观察得知,两个样品主要由ＣｕＣｌ纳米晶和少量的Ｃｕ聚集体构成,其中ＣｕＣｌ纳米晶的直径分别约为３ｎｍ和６ｎｍ;通过室温下测得的光吸收和荧光光谱,发现ＣｕＣｌ激子吸收峰并未出现,而荧光峰向低能方向移动,这可能是激子声子强相互作用引起的结果．在７７Ｋ温度观察到由激子声子耦合而展宽的荧光峰,其峰值近似与量子限制模型的计算结果一致,同时观察到来自陷阱态的宽峰．通过比较３００Ｋ温度下激子荧光峰的展宽和红移量,发现团簇尺寸小的薄膜样品（３ｎｍ）中激子声子相互作用更强,这与理论预测定性一致     

半导体量子点电调制吸收谱一次微分性质的理论分析

分析在电场作用下半导体量子点的介电响应函数,在弱场近似下得到半导体量子点的电调制吸收谱的一次微分性质。由于量子点的量子约束效应,半导体中的电子能带不复存在,成为一系列离散的能级;通常体材料中的电场调制机制不存在了,在电场作用下,量子点中的量子能级会随电场而改变;激子吸收峰红移,因此电场直接影响到介电函数中的激子能级,使激子能级产生与电场强度有关而与时间无关的移动。这样半导体量子点电调制吸收谱成为一     

导电聚合物中极化子动力学的外加电场效应

基于紧束缚近似的Su-Schrieffer-Heeger(SSH)模型,考虑了外电场和Brazovskii-Kirova对称破缺对Hamiltonian的修正,采用非绝热动力学方法研究了一维导电聚合物中正负极化子对的碰撞过程.研究发现外加电场对正负极化子对碰撞的影响至关重要.当外电场很小(约E0<0.02mV/),碰撞的产物是束缚的正负极化子对;在稍强些的电场下,正负极化子可以复合成中性激子,其产率可以达到85%以上;在强电场(约E0>0.2mV/)下则散射成极化子激发态.其中激子形成的细节研究对于如何提高有机电致发光器件的发光效率具有一定的指导意义.     

光子和声子对夫伦克耳激子能谱的影响

本文讨论光子和声子对夫伦克耳激子能谱的影响。声子的作用使激子能带变窄,光子的影响使能带分裂成两支,光子和夫伦克耳激子复合成一种准粒子.     

抛物阱中极化子效应对激子的影响

研究了抛物阱中极化子效应对激子的影响．利用变分法计算了重空穴激子和轻空穴激子的基态能量及其能量移动，所采用的是含有三个变分参数的无分离的试探波函数，结果发现考虑LO声子效应的重空穴激子的基态能量高于裸激子的基态能量，而考虑LO声子效应的轻空穴激子的基态能量低于裸激子的基态能量．     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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     

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