F波段液晶反射移相单元的研究

文章设计了一种工作在F波段的单偶极子液晶反射移相阵列,液晶反射移相阵列由多个单偶极子谐振结构单元、液晶、石英板和金属铜组成。首先通过电磁仿真软件,基于等效介电常数模型对单偶极子液晶反射移相阵列的单元进行设计,分析了液晶材料的不均匀性和各向异性,建立了精准的仿真模型,对液晶反射移相阵列的单元进行分析,最后对实际制作的单偶极子液晶反射移相阵列进行了测试,测试结果显示加载20V偏置电压可以在102GHz附近实现190°以上的相移。     

电场对向列相液晶指向矢取向的影响

讨论了静电场对正介电各向异性的向列相液晶指向矢取向的影响。计算了典型向列相液晶的指向矢偏转角随场强和位置的变化。结果表明,当电场低于阈值电场ＥＣ时指向矢取向不发生偏转,当电场超过ＥＣ时指向矢取向在转变层ξ内与电场方向有较大偏转,而在ξ外几乎沿电场方向,电场越强,偏转角越大。指向矢偏转角、ＥＣ和ξ还与液晶材料各向异性、弹性常数、温度及液晶层厚度等有关     

复合材料三维等效弹性常数的计算

根据层合面上应力和位移的连续性,本文首先讨论了迭层板等效弹性常数的计算。在此基础上,给出了复合材料各组分为正交各向异性材料时,其三维等效弹性常数的计算公式。当复合材料为横观各向同性体时,本文结果与已有计算结果及实验结果相吻合。当复合材料各组分为一般各向异性体时,本文方法亦可用于建立其等效弹性常数的计算公式。     

一种适应恶劣环境的有源液晶显示器的设计

根据温度、振动、冲击、电磁兼容、潮湿等环境特性对有源液晶显示器的影响,提出了对液晶屏进行抗恶劣环境设计的具体加固措施,研究了有源液晶显示器的低温解决方案,包括ITO加热膜加热功率的理论计算、液晶屏内置ITO柔性加热膜工艺、低温加热控制电路等。较好地解决了有源液晶显示器在低温环境下出现的响应速度慢.甚至液晶屏不能显示的问题.此外,还对液晶屏的振动冲击特性、电磁特性进行了研究,提出了具体的解决办法,如加大整机网度,采取屏蔽措施等.     

物理学前沿之一—液晶物理2—液晶相与它的分类及结构特征—

液晶态是物质的一种状态 ,它混有液态和固态 (晶态 )的性质 ,它许多特点也就介于这两者之间。液晶相具有象液体一样的流动性和连续性 ,又具有象晶体一样的各向异性。显然在这中介相 ( meso phase)下物质仍保留着晶体的某种有序排列 ,这样才可能宏观上表现出物理性质的各向异性 ,这样的有序流体就是液晶。它在外观上看 ,普通液体是透明的 ,而液晶却往往是混浊的 ,这也是液晶区别于液体的一个主要特征。不同的液晶相光散射也有差别。大多数液晶是棒状或长条状的。它们可以是较小分子量的 ,也可以是聚合物。小分子量液晶分子的长度约 2 0～ 4 0…     

TN型液晶器件的显示反差对厚度或波长的依赖性

扭曲向列型昌液晶电光显示器件的基本显示方式之一。运用格栅方法计算了ＴＮ型液晶盒的透光率与液晶盒的存长，液晶材料的各向异性因子以及入射光波长的函数关系。结果表明，液晶盒自身的性质也会影响器件在施加电场前后的显示反差。ＴＮ型液晶显示原理仅在一定条件下成立。     

液晶聚合物分子排列调控的研究进展

液晶的应用不仅仅局限于电视或电脑,具有光响应性的液晶在许多领域都存在应用,如平板显示、光学领域、光驱动设备以及许多正在发展的微科技领域. 液晶作为一种中间相的物质,既表现出了液体的流动性,又具有晶态的分子规整排列的性质. 液晶软物质材料具有许多有趣的性质,如自组装性质;长程有序的流动性;分子协同作用;双折射性质和物理性质（光、力、和电）的各向异性;外场诱导的表面分子取向;以及液晶弹性体的刺激响应性形变. 文中综述了具有不同液晶分子取向排列的液晶聚合物的刺激响应性形变,着重介绍了光取向技术诱导液晶分子取向的液晶聚合物的刺激响应性形变行为,并展望了未来液晶材料的设计在微流体和微型机器人领域的潜在应用.     

温度调控下的含向列型液晶缺陷层的光子晶体的光学性质

我们从理论上研究了含向列型液晶缺陷层的光子晶体的光学性质.我们发现,通过改变环境温度可能会引起透射尖峰大的红移或者蓝移.当液晶分子的长轴与入射电场的电矢量不平行也不垂直时,透射曲线中会出现两个透射尖峰,这是因为电场方向沿着和垂直于液晶分子长轴的偏振光具有不同的共振模,在透射曲线尖峰所对应的波长位置,极化偏转也相应得到了很大的增强.计算结果还表明,电场方向平行于液晶分子长轴的偏振光对应的透射峰对温度的变化更加敏感.当温度接近液晶的转变温度时,极化偏转随着温度的变化尤为明显,这是由于液晶由原来的各向异性变为后来的各向同性.这些结果有助于设计性能优异的温度传感器.     

复合材料路面板弹性等效模型

利用弹性力学的刚度等效原理,将结构复杂的复合材料路面板简化为材料均匀的正交异性板,建立弹性等效模型,为此类问题的具体分析提供一种简明规范的方法。利用弹性力学理论,首先计算出中间方形管粘结板的各向刚度,将其等效为相同尺寸的正交异性板,由刚度相等,推导出了等效板的杨氏模量、切变模量和泊松比等结构属性的计算公式;在此基础上,将整个路面板等效为正交异性板,建立了等效板的材料属性公式化计算模型;最后,选用一块具体的路面板,利用有限元分析软件ANSYS,建立路面板和等效板的有限元模型。结果表明:从均布荷载作用下两模型的变形比较图可以看出,路面板模型的最大变形为-14.73 mm,等效板模型最大变形为-13.97mm,两者相差5.2%。由于等效板模型对变形作了一定假定,引起板刚度增大,所以计算出的位移减小,其误差是可以接受的,由此证明了弹性等效模型是正确的。     

液晶和液晶材料

一提到液晶,也许人们会马上联想到手腕上戴的电子表、日常使用的计算器和文字处理机等。那么,液晶究竟是什么呢? 顾名思义,液晶是一种既非液体又非晶体的有机化合物,它是某种有机物质在一定的温度范围内所呈现的一种中间状态,在这种状态下,由于物质分子排列有特殊的取向,分子运动也有特定的规律,因而液晶既具有液体的流动性和表面张力,又呈现某些晶体的光学性质,液体和晶体     

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