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1.
光波的空间相干性分析与研究   总被引:1,自引:0,他引:1  
文章从杨氏干涉实验出发,揭示了光波空间相干性的物理本质。同时指出平面波在自然界根本不存在,存在的是具有一定空间频率和一个有限空间频谱宽度的准平面波。分析了空间频谱具有有限宽度的原因。进一步指出空间频谱宽度与相干面积成反比,空间频率越高的光波偏离光轴的角度越大,空间频谱宽度越大的光波,其衍射发散角越大.  相似文献   

2.
制备了含氟光致聚合物全息材料,测定了其曝光曲线,采用曲线拟合方法,得到了材料的曝光能量常数12.0 mJ/cm2.测定了全息材料的衍射效率随记录信号的空间频率的变化曲线,并根据耦合波理论计算了材料的折射率调制度随记录信号的空间频率的变化.材料的衍射效率和折射率调制度都随所记录信号的空间频率的增加而降低,材料的最大折射率调制度达到3.33×10-3.  相似文献   

3.
本文研究了光导热塑片的结构、原理、记录过程和操作方法,分析了在不同记录条件下全息片的输出空间频率和衍射效率的特点,用热重分析仪和差示扫描量热计测试了热塑料的 TG 曲线和 DSC 曲线,并得到了一系列重要的数据。  相似文献   

4.
当用阿贝的二次衍射理论来理解透镜的成像过程时,透镜后焦面上的每一亮斑(衍射极大值)与平行光通过物平面后物面上的复振幅分布紧密相关,我们称它为空间频率。若物平面上的复振幅分布具有周期性(如衍射光栅),则空间频率是分立的;若物平面上的复振幅分布是  相似文献   

5.
本文给出了一种测量卤化银位相型体积全息的衍射效率η和信噪比和SNR的有效方法,对提高其衍射效率和信噪比的可行性进行了实验探讨,并给出了一些前益的结果。  相似文献   

6.
基于序列视差图像的全息立体显示方法   总被引:7,自引:0,他引:7  
通过获取的序列视差图像,用计算全息与图像处理技术产生了一个全息立体图的显示.在计算全息中采用了基于衍射的光栅条纹生成方法,将视场分为连续的8个区域,每个区域由一个空间频率不同的基本条纹衍射生成,利用迭代算法计算了基本条纹函数.然后对序列视差图像经过二维离散处理,通过光场投影与几何光学成像法,转换到一张全息图上,由包含8个基本条纹的全息素衍射生成序列视差全息图像.从而使观察者获得三维感的立体图像,并给出了实验结果.该算法为基于照片的全息立体图的生成提供了新的方法.  相似文献   

7.
依据光栅光谱仪的工作原理,导出了光栅光谱仪中闪耀光栅在利特罗安装条件下的衍射效率表达式.得到了相应的衍射效率曲线,用其对实验测得的Ne光谱线的相对强度进行了修正.最后,说明了对于较大范围的光栅光谱强度测量值,分析了利用衍射效率进行修正的必要性、有效性和可行性.  相似文献   

8.
自散焦晶体中阵列光束与写入晶格的相互作用研究   总被引:1,自引:0,他引:1  
通过CCD观察了在自散焦光折变晶体中写入光子晶格的动态过程,发现了条纹分裂的一些新的实验现象,认为这是一种空间频率的倍频现象,这种现象是干涉条纹与写入光子晶格之间相互作用的结果,并用相位转移和相位分裂理论对实验现象做了初步解释.实验证明,利用局域光折变效应可以实现空间频率的倍频.  相似文献   

9.
分析了无狭缝彩虹全息图的噪声、衍射效率以及分辨本领。给出了其衍射效率与综合狭缝宽度、噪声与平移距离的关系。  相似文献   

10.
章从理论上分析了两波耦合衍射效率与记录光强比在不同参数下的关系,并用实验进行了验证。理论与实验趋势相一致。  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 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.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
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.  相似文献   

14.
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   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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   

18.
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.  相似文献   

19.
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   

20.
赵英华 《科技信息》2008,(12):219-220
0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation's behavior in their social life throughout the long history is beyond list.  相似文献   

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