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1.
The fluorescence decay of several organic dye molecules intercalated in egg phosphatidylcholine lipid membrane vesicles is
consistent with the existence of two or three prominent lifetime components rather than a single continuous distribution of
lifetimes. The major lifetime components are identified with different sites of solubilization in the membrane. The variation
of the lifetime of the membrane-bound dye was studied as a function of the sucrose concentration, which varied the viscosity
and refractive index of the aqueous solution. The combined effect of viscosity and refractive index on the lifetime of the
dye was used to identify the site of solubilization of the dye in the membrane. The study was useful to identify dye molecules
on the surface which are exposed to the aqueous phase, for which the fluorescence lifetime increased systematically with sucrose
(viscosity effect). More importantly, it was possible in a few cases to identify the dye molecules which are oriented in the
membrane phase, and the fluorescence lifetime decreased systematically with sucrose (refractive index effect). Anomalous values
of order parameters determined from the refractive index effect are explained in terms of an orientational distribution of
the linear dye molecule weighted in favor of mutually orthogonal orientations. 相似文献
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采用平面波展开法数值计算了空气背景中由圆形、正六边形和正方形介质柱构造的二维三角晶格光子晶体禁带结构,并研究了介质方柱旋转角度、介质折射率和填充比对完全光子禁带宽度的影响.结果表明,在低频区,介质方柱旋转17°时,出现最大完全光子禁带,且最大禁带宽度随介质折射率的变化较为稳定.在高频区,介质方柱旋转30°时,完全光子禁带宽度最大;且介质材料折射率n=2.2时即出现完全光子禁带,n=2.6时,完全光子禁带达到最大. 相似文献
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含负折射率缺陷的一维光子晶体的杂质带 总被引:1,自引:1,他引:0
利用传输矩阵方法研究了含负折射率缺陷的一维光子晶体的透射谱.以19个周期的1/4波堆存在3个负折射率缺陷的光子晶体为例进行了数值计算.结果表明:如果改变缺陷的折射率,缺陷模之间的耦合作用将发生改变,带隙中形成的杂质带也随之改变; 当这个折射率取适当值时,在禁带中出现多个尖锐的透射峰,与正折射率缺陷构成的杂质带不同. 相似文献
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Based on the non-symmetric transmission-line method, the band gap structure of disordered chiral photonic crystals (CPC) has
been investigated. The influence of the chiral parameters, the disorder, the periods and the refractive index on the band
gap structure has been discussed. It is found that the photonic band gap (PBG) in CPC is more obvious than that in the conventional
photonic crystals, and the PBG can be increased by increasing the periods or the contrast of the refractive index of the two
media. It is also found that the existence of disorder will influence the band edge of the PBG, and such influence will increase
with the increment of periods or the contrast of the refractive index of the two media. 相似文献
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二维光子晶体层状超晶格透射特性研究 总被引:2,自引:2,他引:0
把平面波展开法(Plane Wave Expansion Method,PWM)用于数值研究圆柱柱体粗细及折射率层状间隔构成的二维光子晶体超晶格的传输特性.数值结果表明,层状超晶格的透射谱中禁带宽度在柱体折射率相同时与粗细柱体半径差异成线性关系,半径相差越大禁带宽度越小,禁带中心位置越向低频方向移动.在半径相同时禁带宽度与层间折射率差异同样成线性关系,折射率相差越大禁带宽度越小,禁带中心位置越向低频方向移动.因此人们可以根据实际应用中的禁带需要利用上述各种可调因素进行调节. 相似文献
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选择枯草芽孢杆菌、黑曲霉孢子和黑曲霉菌丝体等3种典型微生物制备生物样品, 采用显微红外光谱仪对3种微生物样品在2.5—15 μm波段的红外反射光谱进行测定, 基于Kramers-Kronig (K-K)关系计算得到了微生物样品在6—14 μm波段的复折射率. 以水、蛋白质和核酸的红外吸收特性为基础,根据微生物样品的 红外吸收谱线计算了微生物样品含水量. 在3种微生物远红外波段复折射率和含水量的实测数据基础上, 构建了生物颗粒在6—14 μm远红外波段的复折射率模型, 分析了模型的可靠性. 模型的构建对发展生物样品的快速分析、鉴定方法, 进而推动生物气溶胶探测、识别技术进步具有重要意义.
关键词:
光学参数
微生物复折射率模型
远红外波段 相似文献
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An alternative solution for the simultaneous measurement of temperature and refractive index is presented. A local micro-structured fiber Bragg grating(LMSFBG)is formed as the sensing head,in which a standard grating is etched by HF.According to the phase shift theory,the main spectral change of the LMSFBG is the formation of a narrow allowed band,which is strongly dependent on the etching features and the surrounding refractive index.As such,the temperature and refractive index measurements can be achieved by the shifts of the double peaks and narrow allowed band,and their fitting linearity coefficients are 0.996 and 0.994,respectively.Thus,the reflection and transmission peaks of the LMSFBG have a good linear relationship with temperature and refractive index. 相似文献
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Layered heterostructures combining ordinary and negative refractive index materials are shown to display a new type of photonic band gap corresponding to zero (volume) averaged refractive index. Distinct from band gaps induced by Bragg scattering, the zero-n; gap is invariant upon a change of scale length and is insensitive to disorder that is symmetric in the random variable. A metallic structure that exhibits such a band gap is explicitly designed, and its properties are calculated with accurate finite difference time domain simulations. 相似文献
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用特征矩阵法研究一维激光全息光子晶体的禁带特性 总被引:2,自引:1,他引:1
介质中传播方向相反的2束激光干涉可形成具有一维周期结构的体积全息图,而这种全息图可以看作一维光子晶体,称为一维激光全息图光子晶体,用特征矩阵法研究了一维激光全息图光子晶体的透射谱中的禁带随入射角、记录波长、介质折射率、折射率调制度的变化规律。结果表明:当入射角变大,激光波长、介质折射率及介质折射率调制度变小时, 禁带的位置向短波方向移动, 禁带宽度减小。 相似文献
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The purpose of this work is to analyze the effect of the environmental medium on the density of mode (DOM) in a 1-D photonic crystal. The results show that for a symmetric environment, the DOM changes non-monotonously with an increase in the refractive index of the environment medium, while for an asymmetric environment, the DOM increases monotonously with an increase of the refractive index of the substrate. It is found that low DOM at midgap and high DOM at the band edge can be achieved simultaneously only when a photonic crystal works in an environment where the input medium and the substrate have the same refractive indices. The effect of the refractive index on the surrounding material on the band edge laser is also discussed. PACS 42.70.Qs; 71.20.Tx 相似文献
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Luminescence from dye molecules is observed when a liquid dye solution is subjected to a high electric field. The structure and geometry of the electrodes and the refractive index of the dye solution make the cell a waveguide. The radiation pattern of the electroluminescence and the spectral dispersion of the emission are explained. 相似文献
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Muhammad Rizwan Hai-Bo Jin Fida Rehman Zhi-Ling Hou Jing-Bo Li Faheem K. Butt Zulfiqar Ali 《Central European Journal of Physics》2014,12(8):578-581
This paper presents a negative refractive index tunable metamaterial based on F-Shape structure which is capable of achieving dual-band negative permeability and permittivity, thus dual-band negative refractive index. An electromagnetic simulation was performed and effective media parameters were retrieved. Numerical investigations show clear existence of two frequency bands in which permeability and permittivity both are negative. The two negative refractive index bandwidths are from 23.8 GHz to 24.1 GHz and from 28.3 GHz to 34.9 GHz, respectively. The geometry of the structure is simple so it can easily be fabricated. The proposed structure can be used in multiband and broad band devices, as the band range in second negative refractive index region is 7 GHz, for potential applications instead of using complex geometric structures and easily tuned by varying the separation between the horizontal wires. 相似文献
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涂层的折射率是发光光弹性涂层方法采用斜射法应变分离时不可缺少的参数之一. 通过对发光光弹性涂层受斜入射光波激发时, 发射光波沿入射光波原路径返回振幅变化的理论分析, 提出一种基于发光涂层光学菲涅耳响应的折射率在线测量方法. 实验测量了罗丹明B为发光染料的发光光弹性涂层在入射角为60°、波长为465 nm光波激发下的涂层折射率. 测量结果表明: 新的折射率测量方法是可行的, 对于其他用途的发光涂层折射率测量同样适用.
关键词:
折射率
光学测量
光学涂层
光致发光 相似文献