共查询到20条相似文献,搜索用时 9 毫秒
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通过对大量文献的调研,本文分四个部分对手性物质的旋光现象及振动光活性进行了较为全面的介绍,重点介绍了拉曼光活性ROA(RamanOpticalActivity)产生机理、研究状况及对其研究的意义。 相似文献
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氯酸钠晶体的CD光谱及ORD特性研究 总被引:1,自引:2,他引:1
用标准水溶液法生长出氯酸钠晶体,并通过切割、抛光,获得了尺寸为10.9 mm×8.2 mm×4.7mm的透明、规则的氯酸钠晶体.沿六个垂直晶体表面的方向对氯酸钠晶体进行了圆二色性CD光谱及UV光谱的测定,同时采用自制的旋光色散仪对其在上述6个方向的旋光色散特性进行了研究.首次从实验上证实,在紫外区域,氯酸钠晶体在各个方向上均表现出相同的圆二色性;在可见光区域,氯酸钠晶体在各个方向上均表现出相同的旋光色散特性,这一现象与另外一种手性晶体水晶显然是不同的. 相似文献
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Summary An extension of a recent model explaining the stability of chiral molecules is presented here. From the comparison between
the energy reduction produced by the adoption of a chiral form and that produced by a symmetric superposition of chiral states
it is concluded that the true fundamental state of the chiral molecules is the chiral one, which eliminates the well-known
?optical-isomers paradox?. Also, a discussion on the main differences between the approach used here and the previous attempts
of explanation based in the double-well model is made.
The authors of this paper have agreed to not receive the proofs for correction. 相似文献
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M. Cattani 《Il Nuovo Cimento D》1995,17(9):1083-1085
Summary A two-level approach is developed to explain the racemization in dilute gases produced both by natural tunnelling and by elastic
molecular collisions. 相似文献
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根据石英晶体的旋光色散特性,利用光学矩阵方法对多级石英晶体旋光光学滤波器的滤波原理进行了详细的理论分析,推导出多级石英晶体旋光光学滤波器的透射主峰波长和通带半宽度的计算公式.利用分光光度计对单级和多级石英晶体旋光光学滤波器的滤波特性进行了实验研究,结果表明单级和多级石英晶体旋光光学滤波器滤波特性与理论曲线一致.从理论和实验上证明了多级石英晶体旋光光学滤波器与单级相比通带半宽度得到了有效的压缩,且随滤波器级数的增大,压缩的程度也随之增大.
关键词:
光学滤波器
偏振
石英晶体
旋光色散 相似文献
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A planar chiral nanostructure with asymmetric transmission of linearly polarized wave and huge optical activity in near-infrared band 下载免费PDF全文
Just like an electronic diode that allows the electrical current to flow in one direction only, a kind of chiral metamaterial structure with a similar functionality for the electromagnetic wave is proposed. The designed nanostructure that consists of twisted metallic split-ring resonators on both sides of a dielectric substrate achieves asymmetric transmission for a forward and backward propagating linearly polarized wave by numerical simulation in near-infrared band. Difference in transmission efficiency of the optimized structure between the same polarized waves incident from opposite directions can reach a maximum at the communication wavelength (1.55 μm). Moreover, the simulation results of this structure also exhibit strong optical activity and circular dichroism. 相似文献
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利用Müller矩阵和Stokes参量,从石英晶体旋光光学滤波器的透射比公式,推导出了石英品体旋光光学滤波器特征参量的理论计算公式.研究发现,特征参昼的值与滤波器的级数和滤波器中最薄石英晶体的厚度存在直接联系.计算得到一、二、三级石英晶体旋光光学滤波器在不同透射主峰的特征参量,并对其进行了实验验证.通过对不同透射主峰的特征参量进行比较可以看出,对于确定的滤波器,不同透射主峰处的自由光谱范围和通带半峰伞宽随着波长的增大而增大;同一透射主峰处的通带半峰伞宽随滤波器级数的增大而减小. 相似文献
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基于氯酸钠晶体的各向同性和旋光色散特性,利用线偏振光以Brewster角内反射时P分量反射率为零的特性,研制出一种新型内反射旋光光学滤波器,该光学滤波器仅需采用单个偏振片,即可达到良好的滤波效果.利用Mueller矩阵对该滤波器的滤波特性进行理论分析以及实验测试,结果表明对含有532 nm和632.8 nm谱线的线偏振光,改变起偏器角度即可连续调制出射红、绿光的光强,当起偏器较初始位置旋转过133.36°和173.06°时,绿光和红光分别消光,绿光和红光的隔离度可达10 dB.
关键词:
光学滤波器
各向同性
旋光色散
偏振 相似文献
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用PEM-90光弹调制器和透射偏振光的方法,研究D-丙氨酸单晶结构低温变温光学性质的变化.D-丙氨酸单晶是双轴晶体,晶体各向异性,先测定劳埃像,结合D-丙氨酸晶体特征,确定晶面为[010]面.由于电弱力宇称不守恒,D-和L-丙氨基酸分子间存在宇称破缺能差,Salam预言在某临界温度(~250 K)下,D-氨基酸分子会发生二级相变.在218~290 K,通过原位测量D-丙氨酸晶体的旋光性质(I2f/Ide)随温度的变化,发现D-丙氨酸晶体在250 K左右有明显的旋光相变,与前期D-缬氨酸晶体低温相变结果相类似,从而为Salam预言的二级相变提供了佐证. 相似文献
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For several double-helical molecules, the dependence of electronic circular dichroism (ECD) spectra on the molecular and electronic structures is investigated on the basis of TDDFT computations with the B3LYP hybrid functional. The calculations of a model molecule reveal that an acute-angled rotational dihedral angle other than an obtuse-angled rotational dihedral angle between two naphthyls implies Davydov splitting of exciton coupling. For the R enantiomers, the acute-angled rotational dihedral angle implies a negative lowest-energy Cotton effect, which is induced by electron density transfer from binaphthyls to phenyethynyls in the S0?→?S4 excitations. Due to the large positive rotational strength of the S0?→?S1 transition, the lowest-energy Cotton effect of the simplest cyclophane R-1 is positive, where the electron density transfer from phenyethynyls to binaphthyls plays an important role. 相似文献
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研究在超混沌信号调制参数作用下简并光学参量振荡器的混沌同步.计算结果表明,当调制系数在某确定的范围内使系统的最大条件李指数为负数时,两个或更多台简并光学参量振荡器在新的动力学基础上可实现同步或倒同步.同步方式与初始条件和调制系数有关.当初始条件确定的情况下,调制系数取某些值时,系统的同步方式具有突变性. 相似文献
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The planewave response of a chiral sculptured thin film with gyrotropic properties is examined, under the assumption of axial excitation. Although the reflectances and the transmittances are definitely affected by gyrotropy, the circular Bragg phenomenon is still exhibited. Most importantly, structural chirality and gyrotropy contribute cooperatively to transmission optical rotation. 相似文献