混晶GaAs1—xPx：N中N等电子杂质诱发的共振喇曼散射

研究了混晶材料ＧａＡｓ１－ｘＰｘ：Ｎ（ｘ＝０．７６，０．６５）中的共振喇曼散射，在背散射配置的（１００）晶向观察到“禁戒”的ＴＯ声子散射模，这一实验现象解释为在共振激发Ｎｘ杂质带的条件下，由于晶体对称性的喇曼选择定则失效，ＴＯ模成为喇曼活性，根据热猝灭规律，还给出区分共振喇曼散射和热荧光的一个实用判据。     

混晶GaAs_（1－x）P_x：N中N等电子杂质诱发的共振喇曼散射

研究了混晶材料ＧａＡｓ＿（１－ｘ）Ｐ＿ｘ：Ｎ（ｘ＝０．７６，０．６５）中的共振喇曼散射，在背散射配置的（１００）晶向观察到“禁戒”的ＴＯ声子散射模．这一实验现象解释为在共振激发Ｎ＿ｘ杂质带的条件下，由于晶体对称性的喇曼选择定则失效，ＴＯ模成为喇曼活性．根据热猝灭规律，还给出区分共振喇曼散射和热荧光的一个实用判据．     

Nd^3＋：YAG球的声子模谱结构与腔效应

利用黄昆方程从理论上分析了在球形激光Nd^3 ,YAG晶体腔中构成的声子场模谱结构相对体材料在性质和数量上的变化,并利用RENISHAW2000型共焦显微喇曼光谱仪实测了Nd^3 ,YAG晶体球的喇曼光谱,发现喇曼位移在50－150cm^-1的范围内,明显存在声子场腔效应现象,根据理论计算结果和实验结果论证了腔量子声学效应存在的可能性。     

n—Ga1—xAlxAs的电子喇曼散射,束缚声子和DX中心

观测到ｎ－Ｇａ１－ｘＡｌｘＡｓ的束缚声子和电子喇曼散射．对ｎ－Ｇａ１－ｘＡｌｘＡｓ进行喇曼散射实验，揭示了在低温光照条件和组分超过某临界值的合金半导体存在着有效质量型的浅施主能级，引起束缚声子和电子喇曼散射．在较高温度，此能级电子减少到由ＤＸ中心表征的施主深能级．实验结果证实了Ｇａ１－ｘＡｌｘＡｓ的ｎ型杂质具有深－浅双稳特性．根据晶格动力论，浅释了Ｇａ１－ｘＡｌｘＡｓ中施主的电荷态．     

GaAs_(1-x)N_x混晶的喇曼散射研究

室温下采用背散射几何配置,在近共振条件下测量GaAs1-xNx混晶的喇曼散射谱.由于N原子的引入,导致类GaAs的LO1、TO1声子和类GaN的LO2声子线宽变大,禁戒的TO1声子变为喇曼活性;随着N组分的增加,TO1声子强度增大、LO1声子有红移的趋势、LO2声子有蓝移的趋势,根据它们随N组分x移动的速度推断出样品不存在应变效应.另外还讨论了布里渊区边界声子LA(L)与LO(L)、二级喇曼散射谱声子LO2、LO1 LA1(L)以及2LO1随N组分x增大的变化趋势.     

Hg系高Tc超导体(Hg0.8M0.2)Sr2(Y1-xCax)Cu2O6+δ的喇曼和红外光声光谱研究

对Hg系高Tc超导体(Mg0.8Mo0.2)Sr2(Yl-xCaxCu2O6+δ的晶格振动进行了群论分析,给出了该晶体在г点晶格振动的对称性分类.利用红外光声光谱结合喇曼散射研究了该系列样品的声子振动性质.实验结果表明,在喇曼光谱中主要出现145,320,440,578,592Cm-1几个特征振动峰.在中红外吸收光谱(光声光谱)中出现645cm-1特征振动峰.而145,320,440,578,645特征峰强度随掺杂量增加而减弱,其中645峰还向高波数发生位移.本文着重对这些振动模进行了指认,并对其随不同掺杂量的变化特征进行了讨论.     

Nd~(3 ):YAG球的声子模谱结构与腔效应

利用黄昆方程从理论上分析了在球形激光 Nd3 :YAG晶体腔中构成的声子场模谱结构相对体材料在性质和数量上的变化 ,并利用 RENISHAW 2 0 0 0型共焦显微喇曼光谱仪实测了 Nd3 :YAG晶体球的喇曼光谱 ,发现喇曼位移在 5 0～ 15 0 cm- 1 的范围内 ,明显存在声子场腔效应现象 .根据理论计算结果和实验结果论证了腔量子声学效应存在的可能性 .     

GaAs1-xNx混晶的喇曼散射研究

室温下采用背散射几何配置，在近共振条件下测量GaAs1-xNx混晶的喇曼散射谱．由于N原子的引入，导致类GaAs的LO1、TO1声子和类GaN的LO2声子线宽变大．禁戒的TO1声子变为喇曼活性；随着N组分的增加,TO1声子强度增大、LO1声子有红移的趋势、LO2声子有蓝移的趋势．根据它们随N组分x移动的速度推断出样品不存在应变效应．另外还讨论了布里渊区边界声子LA(L)与LO(L)、二级喇曼散射谱声子LO2、LO1 LA1(L)以及2LO1随N组分x增大的变化趋势．     

受激喇曼——斯托克斯散射的增强因子

本文在略述有关受激喇曼散射的发展历史和基本理论以后,从喇曼散射量子理论的跃迁速率方程出发,引进了二个函数形式比例系数的参量。结果,可以对喇曼——斯托克斯散射的情况进行更一般的分析和讨论,并使其在受激散射效应中得到增强的补充处理。     

Ga_(1-x)Al_xAs晶体的2LO和LO_1+LO_2双声子共振喇曼散射

本文研究了Ga_1～xAlxAs晶体的LO、2LO和LO_1+LO_2声子的共振喇曼散射。为了选择带隙对固定激光线调谐的可能性,借助于禁带宽度随Ga_(1-x)AlxAs的组分x而变化以及半导体能带的温度效应来完成本测试工作。用Frohlich耦合机理解释了选择定则禁止的LO声子散射。2LO(Г)和LO_1+LO_2双声子共振喇曼散射都解释为Frohlich相互作用引起的重迭电子一单声子散射过程。测量结果得出室温时Gao.3Alo,7As的直接带隙E_0为2.43eV。     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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