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991.
Elena Fernández Manuel Ortuño Andrés Márquez Rosa Fuentes Inmaculada Pascual 《Optik》2010,121(2):151-158
Holographic data pages were stored in a polyvinyl alcohol (PVA)/acrylamide (AA) photopolymer. This material is formed of AA photopolymers which are considered interesting materials for recording holographic memories. A liquid crystal device was used to modify the object beam and store the data pages in the material. During the storage process, some parameters like exposure time, beam ratio and reading beam intensity were controlled to obtain high image quality after the reconstruction process. The bit error rate (BER) was calculated fitting the histograms of the images to determine what parameters improve the quality of the images. 相似文献
992.
993.
Alexandre Marletta M.L. Vega Y. Galvão Gobato R.M. Faria 《Applied Surface Science》2010,256(10):3018-213
In this work, we have studied the surface morphology of photo-irradiated poly(p-phenylene vinylene) (PPV) thin films by using atomic force microscopy (AFM). We have analyzed the first-order statistical parameters, the height distribution and the distance between selected peaks. The second-order statistical analysis was introduced calculating the auto-covariance function to determine the correlation length between heights. We have observed that the photo-irradiation process produces a surface topology more homogeneous and isotropic such as a normal surface. In addition, the polymer surface irradiation can be used as a new methodology to obtain materials optically modified. 相似文献
994.
995.
Optical characterization of sol gel TiO<Subscript>2</Subscript> monoliths doped with Brilliant Green
S. A. Tomás O. Zelaya R. Palomino R. Lozada O. García J. M. Yáñez A. Ferreira da Silva 《The European physical journal. Special topics》2008,153(1):255-258
Amorphous titanium dioxide monoliths doped with brilliant green (BG) were synthesized by the sol-gel process. The optical
properties of the monoliths were characterized by Photoacoustic Spectroscopy and Photoluminescence Spectroscopy. The absorption
spectra for the BG-doped TiO2 monoliths exhibited two well defined absorption regions: a band below 400 nm corresponding to TiO2 absorption and three absorption bands centered at 424 nm, 588 nm, and 632 nm due to brilliant green. While the undoped TiO2 monoliths showed no luminescence, the doped samples showed a strong luminescence band at 673 nm, which increased its intensity
for increasing organic dye doping. 相似文献
996.
G. A. Martínez-Castañón N. Niño-Martínez F. Martínez-Gutierrez J. R. Martínez-Mendoza Facundo Ruiz 《Journal of nanoparticle research》2008,10(8):1343-1348
Silver nanoparticles with different sizes (7, 29, and 89 nm mean values) were synthesized using gallic acid in an aqueous
chemical reduction method. The nanoparticles were characterized using transmission electron microscopy (TEM), dynamic light
scattering (DLS), X-ray diffraction (XRD), and ultraviolet–visible (UV–Vis) absorption spectroscopy; the antibacterial activity
was assessed using the standard microdilution method, determining the minimum inhibitory concentration (MIC) according to
the National Committee for Clinical Laboratory Standards. From the microscopies studies (TEM) we observed that silver nanoparticles
have spherical (7 and 29 nm) and pseudospherical shape (89 nm) with a narrow size distribution. The sizes of the silver nanoparticles
were controlled by varying some experimental conditions. It was found that the antibacterial activity of the nanoparticles
varies when their size diminishes. 相似文献
997.
Let φ be a supermultiplicative Orlicz function such that the function $t \mapsto \varphi \left( {\sqrt t } \right)$ is equivalent to a convex function. Then each complexn×n matrixT=(τ ij ) i, j satisfies the following eigenvalue estimate: $\left\| {\left( {\lambda _i \left( T \right)} \right)_{i = 1}^n } \right\|_{\ell _\varphi } \leqslant C\left\| ( \right\|\left( {\tau _{ij} } \right)_{i = 1}^n \left\| {_{_{\ell _{\varphi *} } } )_{j = 1}^n } \right\|\ell _{\bar \varphi } $ . Here, ?* stands for Young’s conjugate function of φ, ?, $\bar \varphi $ is the minimal submultiplicative function dominating φ andC>0 a constant depending only on φ. For the power function φ(t)=t p ,p≥2 this is a celebrated result of Johnson, König, Maurey and Retherford from 1979. In this paper we prove the above result within a more general theory of related estimates. 相似文献
998.
Carlos A. FlorentinoJosé M. Mourão João P. Nunes 《Journal of Functional Analysis》2002,192(2):410-424
We extend the coherent state transform (CST) of Hall to the context of abelian varieties by considering them as quotients of the complexification of the abelian group K=U(1)g. We show that this transform, applied to appropriate distributions on K, gives all classical theta functions, and that, by defining on this space of theta functions an inner product related to the K-averaged heat kernel, the unitarity of the CST transform is still preserved. 相似文献
999.
Pedro M Girão 《Comptes Rendus Mathematique》2002,334(2):105-108
Let N?5, a>0, be a smooth bounded domain in , , and 6u62=|?u|22+a|u|22. We prove there exists an α0>0 such that, for all , This inequality implies Cherrier's inequality. To cite this article: P.M. Girão, C. R. Acad. Sci. Paris, Ser. I 334 (2002) 105–108 相似文献
1000.
Tonatiuh Matos Darío Núñez F. Siddhartha Guzmán Erandy Ramírez 《General Relativity and Gravitation》2002,34(2):283-305
In an arbitrary axisymmetric stationary spacetime, we determine the expression for the tangential velocity of test objects following a circular stable geodesic motion in the equatorial plane, as function of the metric coefficients. Next, we impose the condition, observed in large samples of disks galaxies, that the magnitude of such tangential velocity be radii independent in the dark matter dominated region, obtaining a constraint equation among the metric coefficients, and thus arriving to an iff (iff means: if and only if.) condition: The tangential velocity of test particles is radii independent iff the metric coefficients satisfied the mentioned constraint equation. Furthermore, for the static case, the constraint equation can be easily integrated, leaving the spacetime at the equatorial plane essentially with only one independent metric coefficient. With the geometry thus fixed, we compute the Einstein tensor and equate it to an arbitrary stress energy tensor, in order to determine the type of energy-matter which could produce such a geometry. Within an approximation, we deduce a constraint equation among the components of the stress energy tensor. We test in that constraint equation several well known types of matter, which have been proposed as dark matter candidates and are able to point for possible right ones. Finally, we also present the spherically symmetric static case and apply the mentioned procedure to perfect fluid stress energy tensor, recovering the Newtonian result as well as the one obtained in the axisymmetric case. We also present arguments on the need to use GR to study types of matter different than the dust one. 相似文献