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1.
推导了光栅参数与小波频谱值之间的数学关系.采用矢量衍射理论和标量衍射理论两种方法分别计算光栅的衍射效率,并分析两者近似相等的条件,导出光栅参数和小波谱值的关系.以墨西哥帽小波为例计算平面透射光栅的狭缝宽度,获得平面透射光栅参数、衍射效率和墨西哥帽小波谱值的关系.  相似文献   

2.
立体印刷中应用的透镜光栅为柱透镜光栅。本文探索了将矩阵式透镜光栅应用于立体印刷的原理,通过比较矩阵式透镜光栅和柱透镜光栅,指出矩阵式透镜光栅的优点。矩阵式透镜光栅制作的立体画比柱透镜光栅制作的立体画的观察角度更多,能使平面印刷图像取得更好的立体效果。本文给出了具体的制备参数。  相似文献   

3.
从严格耦合波衍射理论出发,在不同入射角、方位角和光栅参数下的情况,计算了矩形亚波长光栅零级反射效率随入射光波长的变化.通过计算结果,找出相对合理的光栅参数,使得当入射光的入射角或方位角发生变化时,光栅反射出不同波段的光,即反射出不同颜色的光.这些研究可应用于防伪技术,为设计和制作防伪光栅提供了设计依据.  相似文献   

4.
基于光纤光栅的振动参数监测及信号处理系统   总被引:3,自引:1,他引:2       下载免费PDF全文
针对光纤光栅传感与其他传感技术相比,有其独特的优点,对光纤光栅传感器进行了理论分析,建立了通过测量光纤光栅传感元件的波长而得到振动参数的理论模型,介绍了测量信号处理系统的结构,作了光纤光栅传感器与加速度传感器的振动参数监测实验,并对实验结果进行了比较。结果表明,光纤光栅传感器的性能很好,可以用于低频振动结构的动态实时监测。  相似文献   

5.
结合亚波长光栅的实际制作工艺,使用耦合波理论进行计算,对影响亚波长光栅零级衍射效率的各个参数进行了全面的分析,排除影响较小和实际无影响的参数,着重对影响较大的几个参数进行分析计算,完成了具有所期望零级衍射效率特性的用于光变色防伪技术的亚波长光栅的设计和制作,样品光栅零级衍射效率的测量结果验证了理论计算结果.  相似文献   

6.
利用光栅标量衍射理论的数值求解法,研究一种可以包埋蛋白质分子的梯形聚合物光栅,用于制作光学生物芯片.通过分析二元光栅结构参数和折射率的变化对±1级和0级衍射光强比的影响,获得优化的光栅结构参数:光栅凹槽深度h0为0.6μm;光栅周期d为4μm;工作波长λ为632.8nm;聚合物折射率n0为1.522;两斜边角度α1为31°,α2为90°;占空比v为0.7;埋入核酸适体厚度h为0.05μm.  相似文献   

7.
利用光栅方程和双光栅成像时各参数方程,研究了双光栅成像中观察到的物体虚像位置与原物位置发生横向偏移的情况,给出了其表达式并且分析了产生横向偏差的影响因素.讨论了光栅参数对横向偏差的影响,给出了其对横向偏移影响的关系图,并对偏移的一些特性进行了定性的分析,得到了一些有益的结论.  相似文献   

8.
该文提出利用光纤光栅来设计光纤光栅Gires-Tournois(G-T)标准具.用传输矩阵法对光纤光栅G-T标准具的光谱特性进行了分析.研究表明,强光栅决定了光纤光栅G-T标准具的反射率和带宽,弱光栅主要影响其时延和色散特性,强弱光栅之间的间隔决定了光纤光栅G-T标准具的自由光谱范围.最后还给出了自由光谱范围为25 GHz的光纤光栅G-T标准具的设计参数.  相似文献   

9.
应用模式匹配法对不同结构参数的布拉格光栅进行了计算,讨论了折射率差、周期结构长度等参数对其滤波特性的影响,同时对布拉格反射器和布拉格滤波器进行了仿真模拟.数值模拟结果表明当折射率差增大时布拉格光栅的反射带宽增大,而当布拉格光栅的周期长度增加时反射峰值增大.  相似文献   

10.
提出了一种新的简单,有效的光纤光栅分析方法-基于多级反射的数值分析方法。利用这种方法可以求得光纤光栅的反射谱、反射谱与光栅参数之间的关系等一系列重要结果。由于参数控制的灵活性,可以将这种方法用于啁啾光栅的特性分析。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
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.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

18.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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