纳米小孔光学近场分布的研究

扫描近场光学显微镜突破了传统远场光学的衍射极限 ,能够获得超高光学分辨率。亚波长尺寸的小孔作为扫描近场光学显微镜中常用的金属膜光纤探针的简化模型。研究光透过小孔后的近场分布特性 ,对理解和分析探针在近场成像中的作用十分重要。采用时域有限差分 (FDTD)方法研究了无限大理想导体屏上纳米小孔的近场分布 ,计算结果表明 ,入射偏振光从小孔出射后发生了退极化 ,即出射光含有与入射光偏振方向垂直的电场分量。文中详细分析了小孔的近场分布特征与退极化之间的关系 ,研究了小孔的形状以及入射光偏振态对近场分布的影响     

光纤光栅中双折射致偏振相关特性

为了研究光纤光栅在横向压力作用下的双折射效应,讨论了光纤光栅中双折射所致的透射特性以及偏振相关特性的变化。通过仿真分析了起偏角对传输特性的影响,研究了双折射效应引起的光纤光栅偏振相关特性。利用传输矩阵法,仿真分析了光栅的参数、结构类型、光纤本征双折射和光栅中光致双折射对偏振相关损耗的影响,并利用邦加球分析了经光栅双折射作用的透射光偏振态的变化。结果表明,双折射的大小和偏振相关损耗以及第一斯托克斯参量之间存在单调递增关系。此结论为利用光纤光栅的偏振特性进行弱压力传感测量提供了基础。     

基于波片的邦加球上任意偏振态的转换方法

为了实现邦加球上任意偏振态之间的转换,在研究波片对偏振态影响规律的基础上,提出了一种基于波片的邦加球上任意偏振态的转换方法.通过琼斯矩阵理论研究得到了波片在邦加球上偏振态的转换规律,λ/2波片能实现邦加球同一纬度值不同半球任意两点对应偏振态的转换,从而实现邦加球上经度的调节;λ/4波片不仅能够实现邦加球上任意一点到赤道对应偏振态,还能实现赤道到0°经线上任意一点对应偏振态的转换,因而可实现纬度的调节.基于上述规律,提出了利用两个λ/2波片和两个λ/4波片实现邦加球上任意两点偏振态之间的转换方法,并给出了具体的转换思路,同时以邦加球上偏振态ζ_A(π/3,π/4)到ζ_E(π/3,π/4)的转换为例,仿真验证了这种方法的有效性.     

基于偏振态颜色编码的晶体应力双折射成像

提出了一种基于双线偏振CCD-全Stokes参量测量的偏振态色度成像新方法.通过分焦面Stokes参量测量与RGB颜色编码相结合,设计并研制了基于双线偏振CCD-全Stokes参量测量的偏振态色度成像系统.利用该系统,获得了晶体模型应力双折射分布的偏振态色度图像,并与传统的光弹性应力测量法进行了比较,偏振态色度成像法不...     

光束的偏振性对全息光栅质量的影响

分析拍摄全息光栅时光束的偏振态对光栅质量的影响，提出利用偏振元件提高所摄光栅的质量，并给出了实验结果。     

一维金属透射光栅的衍射偏振特性的研究

用时域有限差分法(FDTD)和傅里叶变换分别计算了TE、TM波入射时,一维金属光栅的夫琅和费衍射场分布,计算结果表明,当光栅常数小至波长量级时,衍射场明显与光的偏振态有关,而且衍射场分布与光栅周期和缝宽有关,标量衍射中的缺级现象消失.另外,在光栅常数大于波长量级的情况下,如果光栅的缝宽或不透明部分的尺寸接近波长量级时,衍射场也出现明显的偏振相关性.     

基于PDMS自组装褶皱结构的近红外亚波长金属偏振光栅设计分析

提出一种以聚二甲基硅氧烷(PDMS)为基底,结合氧气等离子体氧化处理在PDMS表面生成类二氧化硅刚性层,通过聚对苯二甲酸乙二醇酯(PET)柔性薄膜谐调应力在柔性衬底/刚性薄膜的表面自组装形成有序结构的方法。并制备了周期450 nm、占空0.5、高度100 nm的有序的亚波长正弦光栅结构,以此为基底设计了可用于近红外的金属偏振光栅。结合不同的金属纳米薄膜沉积方法,以严格耦合波理论为分析基础,分析了这三种光栅在近红外波段的偏振性能。分析结果表明,金属层的结构对光栅的偏振性能影响很大,三种结构各有优劣。这种基于自组装结构的加工方法有望解决亚波长金属光栅生产周期长、生产成本高的问题。     

双λ/4波片复合的特性分析

为了得出双λ/4波片复合后的综合偏振特性,利用Stokes矢量和Muller矩阵从理论上分析了线偏振光通过双λ/4波片后出射光的偏振态.结果表明：调整第一只λ/4波片快轴与入射线偏振光光矢量的夹角以及两只λ/4波片快轴之夹角,可以获得不同的偏振态,即：出射光可为线偏振光、圆偏振光或椭圆偏振光,且各夹角不同,出射光的态势及旋性就不同,调整其中某个角度,能够实现偏振光状态的转换.     

光的偏振态对向列相液晶中光栅衍射的影响

通过二波耦合实验研究了不同偏振态的两束写入光在向列相液晶中形成光栅的衍射现象。实验发现,水平偏振态(P-P偏振)照射时形成的光栅具有比竖直偏振态(S-S偏振)照射时大得多的能量耦合,且能量耦合方向完全相反。更重要的是,当光栅形成之后改变其中一束光的偏振方向时,透射光和衍射光的强度会随着其中一束光的偏振态的改变而变化。可见,光的偏振态在决定NLC分子非线性取向时是一个非常重要的参数,在以后的光电子功能器件应用中与偏振光相关的分子取向产生的非线性光学现象将会非常有用。     

实部虚部关联的泵噪声对激光统计性质的影响

在增益模型的基础上,考虑平方色噪声,把泵噪声实部虚部间的关联强度λp引入光强的朗之万方程,分析λp作为一个新的重要参数对光强的定态几率分布Qst(I)的影响.发现λp在不同的参数下显著改变光强的定态几率分布曲线,并且得到一个新的现象,即当两个不同的关联强度值λp1和λp2满足方程λ2p1 λ2p2=1时,光强的定态几率分布曲线重合.同时研究了当关联λ存在时,其他参数对光强定态几率分布的影响.     

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