钨酸铅晶体中F型色心电子结构的研究

运用相对论性的密度泛函离散变分（DV-Xα）方法模拟计算了PbWO4（PWO）晶体中F型色心的电子结构,得到了PWO晶体的态密度分布,讨论了色心的可能光学跃迁模式,并用过渡态方法计算了跃迁能量。计算结果表明,F、F^＋心在PWO晶体的禁带中引入了施主能级,F、F^＋心可向W 5d轨道发生跃迁,其跃迁能分别是1.83eV、2.28eV,因此,可推断F、F^＋心能引起PWO晶体中680nm、550nm的吸收。     

NaCl晶体中电子型色心的电子结构研究

运用密度泛函离散变分（DV-Xα）方法研究了NaCl晶体中可能存在的色心,模拟计算得到含色心的NaCl晶体的电子结构．计算结果表明,F、F2心在禁带中引入了新的能级;分析了可能存在的光学跃迁,并用过渡态方法计算得到相应的跃迁能量为2．74eV和1．74eV．该计算结果与实验测得的吸收光谱的峰值位置吻合较好．而F^＋心不存在光学跃迁吸收,但使晶体的禁带宽度变窄．计算结果还解释了NaCl晶体吸收光谱的结构起因．     

SrWO4晶体中F型色心电子结构的研究

运用相对论的密度泛函离散变分法(DV-Xa)研究了SrWO4晶体中F型色心的电子结构.计算结果表明,F和F+心在禁带中引入了新的施主能级;从施主能级到导带底的电子跃迁能分别是1.858,2.14 eV,这分别与669,581 nm的吸收带相对应.由此说明SrWO4晶体中669,581 nm吸收带起源于晶体中的F和F+心.     

第一性原理研究BaMoO_4晶体中F和F~+色心的电子结构

运用相对论密度泛函离散变分法(DV-Xa)计算了BaM004晶体中F和F+色心的电子结构.结果表明:F和F+心在禁带中引入了新的施主能级,采用过渡态的方法计算得到了F和F+心到导带底部的跃迁能量分别为1.86 eV和2.11 eV,对应668 nm和590 nm的吸收.由此说明BaMoO4晶体中668 am和590 nm吸收带起源于晶体中的F和F+心.     

PbWO4晶体F心及F+心吸收带的能级计算

采用离散变分法计算了PbWO4晶体的能带结构，并用F心及F^ 心的类氢离子1S波函数结合离散变分法计算了F心及F^ 心的电子基态能级，计算结果表明，F心及F^ 心电子基态能级分布在禁带中，分别位于距导带底1.97eV(630nm)及2.36eV(525nm)处，它们的吸收跃迁对应于基态到导带底的跃迁，使晶体呈现F心及F^ 心吸收带，化学计量PbWO4晶体的辐照诱导吸收谱位于500-700nm，呈现一个宽吸收带，高斯分解的结果表明；该吸收带是由两个峰值分别位于550nm和680nm的吸收带叠加而成的，这两个吸收带分别对应于F^ 心及F心吸收带，计算结果与实验数据吻合较好。     

对不同掺杂浓度La~(3 )∶PbWO_4晶体电子结构的研究

采用缺陷化学方法讨论了PbWO4晶体中不同浓度掺La3 时可能存在的缺陷团簇模型.通过GULP计算软件模拟计算了缺陷团簇中La3 离子最可能的替位位置,并通过基于密度泛函理论的离散变分DV Xα方法计算得到相应的La3 ∶PWO4晶体的电子态密度.计算得到低浓度掺杂时晶体的禁带宽度变宽,高浓度掺杂时晶体的禁带宽度变窄.实验测得低浓度掺La3 时晶体的吸收边紫移,高浓度掺La3 时晶体的吸收边红移,计算结果与实验结果相符.计算表明,La3 ∶PWO4晶体中掺La3 可以有效地抑制420 nm吸收.     

光学厚度对一维光子晶体禁带宽度的调制

采用参数调节法研究了光学厚度对一维光子晶体禁带宽度的调制作用,通过计算得到禁带宽度的解析表达式及禁带宽度随两层光子晶体光学厚度的变化规律。当两层光子晶体的光学厚度都等于λ0/4时,禁带宽度达到最大,说明用调节一维光子晶体的光学厚度来实现对禁带宽度的调制是有效的。     

对不同掺杂浓度La3+:PbWO4晶体电子结构的研究

采用缺陷化学方法讨论了PbWO4晶体中不同浓度掺La^3＋时可能存在的缺陷团簇模型，通过GULP计算软件模拟计算了缺陷团簇中La^3＋离子最可能的替位位置，并通过基于密度泛函理论的离散变分DV-Xa方法计算得到相应的La3^＋：PWO4晶体的电子态密度．计算得到低浓度掺杂时晶体的禁带宽度变宽，高浓度掺杂时晶体的禁带宽度变窄．实验测得低浓度掺La^3＋时晶体的吸收边紫移，高浓度掺La^3＋时晶体的吸收边红移，计算结果与实验结果相符、计算表明，La^3＋：PWO4晶体中掺La^3＋可以有效地抑制420nm吸收.     

Er3+:Y0.5Gd0.5VO4晶体中Er3+离子的光谱特性

用提拉法(CZ法)生长出大尺寸、光学质量好的Er3 :Y0.5Gd0.5VO4单晶.在室温下,测量Er3 :Y0.5Gd0.5VO4晶体的吸收光谱、荧光光谱以及上转换荧光;利用Judd-Ofelt理论计算了Er3 离子在Y0.5Gd0.5VO4晶体中的振子强度P JJ′、自发辐射跃迁几率AJJ′和激发态荧光寿命τJ等光谱参数,在此基础上得出了Er3 :Y0.5Gd0.5VO4晶体的光学特性.     

量子点CuInS_2晶体的近红外光学性质研究

利用密度泛函理论,对CuInS_2量子点晶体进行光学性质预测,得到CuInS_2晶体的理想禁带宽度为1. 08 eV,属于直接带隙半导体.同时计算了材料介电常数,折射系数,吸收系数及光损耗系数谱图.结合图谱分析,明确了CuInS_2量子点晶体位于波长范围750～1 500 nm表现出很好的透光性能.量子点CuInS_2晶体可能成为一种潜在的近红外成像示踪材料.本文拟使用CuInS_2量子点晶体标记纳米粒子,实现示踪的效果.     

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