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991.
Entao Tian Ying Ma Liying Cui Jingxia Wang Yanlin Song Lei Jiang 《Macromolecular rapid communications》2009,30(20):1719-1724
In this work, a color‐oscillating system is first developed by combining the intrinsic peristaltic motion of a Landolt pH‐oscillator with the structure color of a well‐designed pH‐sensitive photonic crystal hydrogel. As a result, the pH oscillation reaction procedure could be distinctly monitored by the distinct change of structure color/optic signal. The oscillation rhythm of the pH well coincides with that of the stopband/structure color. The oscillation detail of each cycle can also be clearly monitored by color change. This work would be of great significance for the promising applications of real‐time monitoring of the microactuator by optical signal or structure color.
992.
采用磁化等离子体的分段线性电流密度卷积时域有限差分(PLCDRC-FDTD)算法研究具有单一缺陷层的一维磁化等离子体光子晶体的缺陷模特性. 从频域角度分析得到微分高斯脉冲的透射率,并讨论该光子晶体的缺陷层厚度、位置、周期常数和等离子体参数对其缺陷模的影响. 结果表明,改变位置和周期常数不会影响缺陷模的频率,改变缺陷层的厚度可以增加缺陷模数,改变等离子体参数能同时影响缺陷模的频率和峰值.
关键词:
磁化等离子体光子晶体
光子晶体
缺陷模
时域有限差分法 相似文献
993.
Pattern formation and self-organization are phenomena that occur across the board, in animate and inanimate systems. In this paper, we rely on the constructal law to explain the generation of patterns (shapes, structures) in aggregates of organisms-pedestrian crowds and stony corals. In pedestrian crowds a variety of patterns are often observed, from ‘chaotic’ appearances to spontaneous organization in lanes of uniform walking direction. Stony corals and other organisms also present intraspecific variability in shape. We show that flow systems develop in time patterns which provide easier access to the nutrients and space, within a set of constraints imposed by each situation. Flow systems have the freedom to morph their shape in search for architectures that allows them to have greater access to the space that they inhabit. We identify the mechanisms allowing pedestrians to evolve in space and time. We also show that stony corals may develop branched or spherical shapes, depending on which shape performs best in response to the environmental conditions. The constructal law allows systems with complex internal flows to be described and understood for a unified view. 相似文献
994.
B. Rossi G. Mariotto E. Ambrosi H. L. Monaco 《Journal of Raman spectroscopy : JRS》2009,40(12):1844-1848
The vibrational properties of both wild‐type and selenomethionine (SeMet)‐substituted protein SOUL crystals have been investigated here by Raman spectroscopy. Several Raman peaks observed in the spectra of methionine and SeMet were identified as specific markers. The unambiguous assignment of these peaks has been inferred by comparing the experimental Raman spectra of the pure amino acids, recorded in solid state and in aqueous solution, and the Raman intensities computed using quantum chemical calculations. Moreover, a quantitative evaluation of the relative amount of SeMet replacement in the crystals of protein SOUL labelled with SeMet has been estimated through the ratio between the Raman intensities of marker peaks. These results offer evidence of the potential of Raman microscopy as a reliable and non‐invasive tool for novel in‐depth structural investigations in biocrystallography. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
995.
A. H. Mkrtchyan R. P. Vardapetyan E. M. Harutyunyan A. V. Khachatryan V. V. Nalbandyan H. R. Muradyan 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2009,44(4):194-196
Interaction of Mössbauer gamma radiation with ultrasound vibrations in group AIIBVI single crystals of CdS and CdSe with Fe57 impurity nuclei under action of infrared radiation is investigated. It is shown that the infrared irradiation excites a phonon field in single crystals. Similar to the case of optical irradiation of single crystals the shape of their Mössbauer spectrum is modified. The effect of double modulation of resonant gamma radiation by infrared radiation has been observed. 相似文献
996.
W. Stille 《The European physical journal. E, Soft matter》2009,28(1):57-71
The deformation of cholesteric elastomers by mechanical stress applied parallel to the helix axis is studied by calculation
of the free-energy density. The Frank-elasticity contribution is taken into account. A chiral solvent, present at cross-linking
time, is in general considered to be replaced after cross-linking by a solvent with different chirality. Two special cases
considered are zero and unchanged solvent chirality, the first known as that of imprinted cholesteric elastomers, the latter
equivalent to intrinsic cholesteric elastomers with chemically attached chiral groups. Depending on material parameters and
imposed strain, the director can show a tilt towards the helix axis up to the maximum tilt, corresponding to a nematic state.
In case of intrinsic elastomers with low conformation anisotropy, direct transitions from untilted to nematic states can be
induced by straining. The helix structure of the director field is coarsened with an average wave number different to that
of the information inscribed in the network at cross-linking time, if this lowers the average free-energy density. Switching
between different states can be achieved with electric fields of reasonable values applied parallel to the helix axis. Spectra
of the reflection of polarized light are calculated. 相似文献
997.
Oettel M Domínguez A Tasinkevych M Dietrich S 《The European physical journal. E, Soft matter》2009,28(2):99-111
The elastic and capillary interactions between a pair of colloidal particles trapped on top of a nematic film are studied
theoretically for large separations d. The elastic interaction is repulsive and of quadrupolar type, varying as d-5. For macroscopically thick films, the capillary interaction is likewise repulsive and proportional to d-5 as a consequence of mechanical isolation of the system comprised of the colloids and the interface. A finite film thickness
introduces a nonvanishing force on the system (exerted by the substrate supporting the film) leading to logarithmically varying
capillary attractions. However, their strength turns out to be too small to be of importance for the recently observed pattern
formation of colloidal droplets on nematic films. 相似文献
998.
S. Ertman A. Czapla T. R. Woliński T. Nasi?owski H. Thienpont E. Nowinowski-Kruszelnicki R. D?browski 《Opto-Electronics Review》2009,17(2):150-155
Photonic liquid crystal fibers have already been demonstrated as a promising perspective for creation of new classes of dynamically
tunable optical fiber devices. By combining different geometries of photonic crystal fibers with a variety of different liquid
crystals it is possible to obtain a new generation of fibers with dynamically tunable properties, e.g., transmission spectra,
attenuation or dispersion.
In this paper, tunable birefringence in a commercially available highly birefringent Blazephotonics PM-1550-01 photonic crystal
fiber selectively filled with a low birefringence liquid crystal has been experimentally demonstrated. Theses experimental
results have been compared with simulations based on the multipole method. 相似文献
999.
D. Budaszewski A. W. Domański A. Czapla S. Ertman T. R. Woliński T. Nasilowski H. Thienpont 《Opto-Electronics Review》2009,17(2):156-160
In the paper we analyze microstructured optical fibers filled with typical nematic liquid crystals, i.e., 5CB and 6CHBT under
influence of external electric field or temperature. We use the modified Mueller matrix method with an additional depolarization
matrix to calculate degree of polarization changes of the light propagating in the liquid-crystal infiltrated microstructured
optical fibers. Preliminary experimental results of light depolarization measurements during propagation in these microstructured
fibers are also presented. 相似文献
1000.
Binding energy of hydrogenic impurity states in an inverse parabolic quantum well under static external fields 总被引:1,自引:0,他引:1
S. Baskoutas A. F. Terzis 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(2):237-244
In the present theoretical study, we investigate the influence of external fields (electric and/or magnetic) on the binding
energy of hydrogenic impurities in a GaAs/Ga1-xAlxAs inverse parabolic quantum well, in which the parabolicity depends on the Al concentrations at the well center. Our calculations
have been based on the potential morphing method in the effective mass approximation. The systematic theoretical investigation
contains results with all possible combinations of the involved parameters, as quantum well width, Al concentrations at the
well center, position of the impurity and magnitudes of the external fields. 相似文献