卷积法和角谱法再现显微全息图时补零数的研究

针对全息图补零法的补零数对再现像和系统效率的影响,结合数字全息显微术中卷积法和角谱法数字再现的原理和再现面与物体放大像尺寸的关系,研究补零数对再现像和系统效率的影响,并采用梯度法来评价再现像的质量。对全息图采用频率滤波提取实像或共轭像的频谱,再采用卷积法或角谱法数字再现,获得物体的放大像。结合再现像的质量和效率两方面因素,提出了补零数的选取依据,即以再现面的物理尺寸不小于物体的放大像时的最小补零数作为最佳补零数,此时能以最小的计算量获得最高质量的再现像。通过实验验证,结果与理论分析一致,证明了选取补零数的依据。     

基于数字全息和计算全息的动态三色全息三维显示

为了实现数字全息图和计算全息图再现像的融合,将数字全息、计算全息与空间光调制器相结合,构建了一个数字化动态三色全息三维显示系统,用数字全息术记录实际物体的全息图,用计算全息术计算得到虚拟物体的全息图,然后将2种全息图输入到空间光调制器中.结果显示:通过空间光调制器的衍射,在空间中得到虚拟信息与实际信息融合的再现像.该方法实现了数字全息图和计算全息图再现像的融合,达到了增强真实物体的三维显示效果.     

基于TN-LCSLM的计算全息实时再现

分析了计算全息图编码原理,介绍了用MATLAB编程计算全息编码的主要步骤.用Matlab模拟了计算全息图的再现结果.将编码全息图实时输出到高分辨扭曲向列型液晶空间光调制器(TN LCSLM)上,和傅里叶变换透镜、滤波器、CCD等组成计算全息实时再现系统,实现了全息图的实时再现.最后,分析了提高再现像质量的方法.     

计算机与光学相结合的体视全息三维显示

在计算机制全息技术和光学全息技术的基础上,研究用计算机-光学方法联合制作体视全息三维立体显示技术.根据人眼立体视觉原理获取三维物体带有视差信息的体视图,通过计算机计算得到计算全息图H1;将H1严格对位,用激光再现获得带有视差信息的再现像,并以此再现像为对象,用光学全息的方法拍摄彩虹全息图H2;用白光再现H2,通过双眼综合出三维立体图像.在全息图的计算过程中,采用快速傅里叶变换算法提高了计算速度,将计算全息与光学全息相结合,发挥了各自的优势.     

计算全息的误差综合修正

为了使计算全息图用于单模光纤场分布测试,必须研制高质量的计算全息图。我们提出误差修正的新方法——误差综合修正法。并研制出了高质量的用于单模光纤场分布测试的计算全息图。本文首先讨论罗曼Ⅲ型傅里叶变换计算全息图的编码及其误差,然后讨论误差综合修正方法,最后给出应用误差综合修正后所得到的计算全息图的模拟再现像和在实际光学系统中得到的再现像。     

用DMD光学再现全息图的研究

构建了以电荷耦合器件(CCD)为全息记录设备,数字微反射器（DMD）为光学再现设备的数字全息系统.从计算全息图和CCD记录全息图两个方面研究了用DMD光学再现物光场.实验结果表明两种情况下DMD都能很好地再现出物光场,计算机制全息图的再现像质量要比CCD记录全息图的要好些.对CCD直接记录的全息图进行边缘锐化后,其再现像的对比度增强,再现质量得到显著改善.这些实验结果有利于该技术应用于实时干涉计量等工程领域,具有潜在的实用前景.     

修正离轴参考光计算全息图的数值再现及像质评价研究

修正离轴参考光计算全息图制作方法中,博奇、黄氏及李维汉型三种计算全息图实质上是分别在全息图函数中加入新的偏置项,从而形成不同的全息图编码方式.由于这三种编码方式所加的偏置项不同,其对再现像质量的影响也不相同.本文将计算全息技术与数字全息技术相结合,实现了博奇、黄氏及李维汉型三种计算全息图的设计制作、数据处理、再现过程的全数字化.一方面,采用计算机对计算全息图进行数字化滤波,在频谱域消除虚像和零级像,得到了单一的清晰实像;另一方面,通过引入信噪比和图像亮度等参数指标,对以上三种计算全息图的再现像质量进行评价     

点光源菲涅耳二元全息图再现像质的分析

对点光源菲涅耳二元全息图再现像进行了量化分析，同正弦菲涅耳全息图再现像比较，二元全息再现时除了背景噪声增大及出现高级次的像以外，像质基本不变并提高了衍射效率．这一结果为计算机制全息的实际应用开辟了一条新的思路．     

计算全息图再现像的光强补偿

考虑到光栅衍射因子作用会影响到计算全息图再现像时的光强分布，造成再现及其共轭像边缘暗、中央亮的情况，在物采样时，加进一反射因子，使再现光强得到了补偿。     

柴油喷雾粒子全息再现像的图像处理

本研究从分析喷雾再现粒子像的光场分布出发,探讨了灰度阈值的选取对粒径测量误差的影响.通过对粒子图像直方图的实验研究分析,提出了灰度阈值的自动选择方法和实现了多阈值自动分割,以解决不均匀背景粒子再现像的测量精度问题.通过对粒子再现像的调焦过程光场分布计算分析和试验研究,提出了一个简单可行的判焦准则,利用此准则可以加快判焦速度.     

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