八边形光子晶体光纤的特性研究

采用矢量波束传播法对正八边形光子晶体光纤色散和模场面积进行了数值模拟和分析.结果表明通过改变空气孔孔径d和相邻不同层空气孔间距Λ,可以使正八边形光子晶体光纤的色散曲线在很宽的波长范围内保持色散平坦并具有较低的色散值.选取合适的结构参数可以在1.45～1.65um波长范围内构造超色散平坦光子晶体光纤.     

1.15-1.35μm具有平坦色散的PBG光子晶体光纤的设计

利用时城有限盖分法（FDTD）设计了在1．15-1．35μm具有平坦色散的PBG光子晶体光纤。将光子晶体光纤的总色散分为波导色散和材料色散两部分分别计算，并利用包层空气孔间距以、包层空气孔径与空气孔间距的比值d／Λ及中心缺陷孔径与包层空气孔间距的比值r／Λ来改变波导色散。试光纤对于DWDM光纤通信系统具有重要意义。     

改进型双层芯光子晶体光纤宽带补偿特性分析及设计

针对现有的补偿光子晶体光纤无法较好地实现宽带色散补偿问题,本文利用多极法分析了色散和光纤结构参数之间的变化关系。通过减小同轴双层芯光子晶体纤结构中双芯之间的空气孔直径,并随后增大孔间距,设计出了一种在C波段范围内与标准单模光纤G.652色散系数相补偿的光子晶体光纤,实现了这一波段的宽带补偿,模拟结果表明具有很好的补偿效果。     

近零平坦色散高非线性光子晶体光纤的研究和设计

利用有效折射率法对光子晶体光纤非线性和色散进行了计算;模拟了光纤空气孔直径和孔间距对光纤特性的影响,并进行了分析;最后设计了一种零色散点在850nm附近的近零平坦色散高非线性光子晶体光纤,这种光纤在研究光纤非线性现象时有重要的价值.     

硅光子晶体光纤中太赫兹波的衰减特性分析

本文采用有限元法分析了太赫兹波在光子晶体光纤中的传输特性,并对比在不同空气孔径下,太赫兹波在光子晶体光纤中的场分布和衰减。当d/Λ=0.95时,太赫兹光子晶体波导的传输损耗达到0.0012dB/m,满足太赫兹波传输要求。     

太赫兹光子晶体光纤单模传输特性的研究

利用全矢量有限元法并结合损耗理论对全内反射型太赫兹光子晶体光纤的单模传输带宽进行了深入的研究。结果表明,光纤的限制损耗以及单模传输带宽可以通过改变光子晶体光纤的占空比、空气孔间距、空气孔层数等结构参数进行灵活的调节,并与其他文献利用归一化频率法得到的结果相吻合。     

PBG光子晶体光纤中空气导光条件的研究

应用平面波法分析了带隙效应导引光子晶体光纤(Photonicbandgapguidingfibers,PBG PCFs)中实现空气通道导光必须满足的条件,计算机仿真了蜂窝和三角形两种不同结构的PBG PCFs的空气导光性能。计算结果表明,要实现空气导光,空气孔直径与周期的比值d/Λ必须大于某一特定值:对于蜂窝结构该比值为0.84,而对于三角形结构该比值为0.59;在特定的d/Λ下,空气导光的波长范围随Λ可变。     

光子晶体光纤非线性系数的数值分析

利用全矢量有限元法对六重对称的全内反射型光子晶体光纤的非线性系数进行了数值分析，模拟了光子晶体光纤的非线性系数与纤芯材料折射率、空气孔直径、孔间距的关系，结果表明在其它参量相同的情况下，纤芯材料折射率的变化对光子晶体光纤的非线性系数有着明显的影响，尤其是在输入光波长小于1.0μm范围内,在波长为0.5μm处，当纤芯材料折射率为1．45时非线性系数为0．4047m^-1W^-1，但纤芯材料折射率为1．40时非线性系数高达1．792m^-1W^-1。     

压缩型光子晶体光纤的双折射特性

定义了压缩率的概念,提出了一个可以构建三角格子、压缩三角格子、正方格子和矩形格子光子晶体光纤的模型;基于此压缩率模型,应用超格子构造法研究了压缩对光子晶体光纤双折射特性的影响.结果表明,通过改变光子晶体光纤晶格的压缩率可以获得较大的双折射.另外,分析了光纤双折射随晶格常数和空气孔直径的变化规律,并报导了光纤双折射符号随着空气孔直径变化而发生多次改变的现象.     

正八边形双芯光子晶体光纤的温度传感特性

正8边形光子晶体光纤包层结构较正6边形更接近于圆,因此它具有限制损耗低,非线性系数低,色散平坦的优点.设计了一种正8边形双椭圆孔纤芯光子晶体光纤,分析了这种光纤填充高折射率温度系数敏感液体后的温度特性.采用全矢量有限元法和光纤的模式耦合理论研究了温度对其有效折射率、耦合长度、模场分布和限制损耗的影响,计算并分析了具有相同结构参数的正6边形光子晶体光纤在1.55μm低损耗窗口的限制损耗.研究表明,模场分布与温度和波长有关,有效折射率和耦合长度都随着温度升高而减小,限制损耗随温度升高递增.结构一定时,长波长条件下和小椭圆率时具有更好的温度敏感特性;结构不同时,大占空比的光子晶体光纤具有更好的温度敏感特性.在波长1.55μm、相同温度下所设计的正8边形光子晶体光纤与正6边形光子晶体光纤的限制损耗相比大大减小.     

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.     

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.     

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.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

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.