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951.
Boris AV Munzar D Kovaleva NN Liang B Lin CT Dubroka A Pimenov AV Holden T Keimer B Mathis YL Bernhard C 《Physical review letters》2002,89(27):277001
The far-infrared (FIR) c axis conductivity of a Bi2223 crystal has been measured by ellipsometry. Below T(c) a strong absorption band develops near 500 cm(-1), corresponding to a transverse Josephson plasmon. The related increase in FIR spectral weight leads to a giant violation of the Ferrell-Glover-Tinkham sum rule. The gain in c axis kinetic energy accounts for a sizable part of the condensation energy. We also observe phonon anomalies which suggest that the Josephson currents lead to a drastic variation of the local electric field within the block of closely spaced CuO2 planes. 相似文献
952.
We demonstrate optical data storage in optical fibers and reconstruction by use of low-coherence spectral interferometry. The information was stored by means of writing fiber Bragg gratings with different central wavelengths at different locations of the fiber. We need only a single short pulse is needed to read all the stored data. The maximum theoretical reconstruction rate that can be obtained with our technique is 10 Tbits/s. Our storage technique can be useful for identifying users in optical communication networks. 相似文献
953.
Dephasing of one-particle states in closed quantum dots is analyzed within the framework of random matrix theory and the master equation. The combination of this analysis with recent experiments on the magnetoconductance allows, for the first time, the evaluation of the dephasing times of closed quantum dots. These dephasing times turn out to be dependent on the mean level spacing and significantly enhanced as compared with the case of open dots. Moreover, the experimental data available are consistent with the prediction that the dephasing of one-particle states in finite closed systems disappears at low enough energies and temperatures. 相似文献
954.
Bogdanovic G Sennerfors T Zhmud B Tiberg F 《Journal of colloid and interface science》2002,255(1):44-51
The formation and structure of multilayer films containing a cationic polyelectrolyte and anionic silica nanoparticles were studied by means of ellipsometry and atomic force microscopy. Three types of silica particles of different sizes were examined. The density and thickness of the films as well as the adsorption kinetics appear to be strongly dependent on the choice of particle; smaller particles favor the formation of smooth and dense films with a higher content of the inorganic component. 相似文献
955.
956.
Boris N. Kuvshinov 《International Journal of Solids and Structures》2008,45(5):1352-1384
We derive explicit, closed-form expressions describing elastic and piezoelectric deformations due to polyhedral inclusions in uniform half-space and bi-materials. Our analysis is based on the linear elasticity theory and Green’s function method. The method involves evaluation of volume and surface integrals of harmonic and bi-harmonic potentials. In case of polyhedra, such integrals are expressed through algebraic functions. Our results generalize numerous studies on this subject, and they allow to obtain fully analytical solutions for a number of physical and engineering problems. In the limiting case of an infinite space, our relations have an essentially more compact form, than relations obtained by other authors. We present solutions to classical Mindlin and Cherruti problems. We describe the elastic relaxation of a misfitting polygonal quantum dot in bi-materials assuming isotropic and vertically isotropic properties. It is explained how to analyze non-hydrostatic and non-uniform inclusions. We also study piezoelectric fields induced by inclusions in materials with cubic and hexagonal lattices. Among other results, we have found that a cubic inclusion in an isotropic material reproduces fields of quantum dots in GaAs (0, 0, 1) and GaAs (1, 1, 1) depending on the orientation of the cube. This suggests that one can qualitatively model crystals with different lattices by choosing an appropriate inclusion shape. 相似文献
957.
Marianna A. Shubov Boris P. Belinskiy Clyde F. Martin 《Mathematical Methods in the Applied Sciences》2001,24(15):1139-1167
We consider a class of non‐selfadjoint operators generated by the equation and the boundary conditions, which govern small vibrations of an ideal filament with non‐conservative boundary conditions at one end and a heavy load at the other end. The filament has a non‐constant density and is subject to a viscous damping with a non‐constant damping coefficient. The boundary conditions contain two arbitrary complex parameters. We derive the spectral asymptotics for the aforementioned two‐parameter family of non‐selfadjoint operators. In the forthcoming papers, based on the asymptotical results of the present paper, we will prove the Riesz basis property of the eigenfunctions. The spectral results obtained in the aforementioned papers will allow us to solve boundary and/or distributed controllability problems for the filament using the spectral decomposition method. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
958.
Detonation diffraction through different geometries 总被引:1,自引:0,他引:1
We performed the study of the diffraction of a self-sustained detonation from a cylindrical tube (of inner diameter d) through different geometric configurations in order to characterise the transmission processes and to quantify the transmission
criteria to the reception chamber. For the diffraction from a tube to the open space the transmission criteria is expressed
by d
c
= k
c
·λ (with λ the detonation cell size and k
c
depending on the mixture and on the operture configuration, classically 13 for alkane mixtures with oxygen). The studied
geometries are: (a) a sharp increase of diameter (D/d > 1) with and without a central obstacle in the diffracting section, (b) a conical divergent with a central obstacle in the
diffracting section and (c) an inversed intermediate one end closed tube insuring a double reflection before a final diffraction
between the initiator tube and the reception chamber. The results for case A show that the reinitiation process depends on
the ratio d/λ. For ratios below k
c
the re-ignition takes place at the receptor tube wall and at a fixed distance from the step, i.e. closely after the diffracted
shock reflection shows a Mach stem configuration. For ratios below a limit ratio k
lim (which depends on D/d) the re-ignition distance increases with the decrease of d/λ. For both case A and B the introduction of a central obstacle (of blockage ratio BR = 0.5) at the exit of the initiator
tube decreases the critical transmission ratio k
c
by 50%. The results in configuration C show that the re-ignition process depends both on d/λ and the geometric conditions. Optimal configuration is found that provides the transmission through the two successive reflections
(from d = 26 mm to D
ch = 200 mm) at as small d/λ as 2.2 whatever the intermediate diameter D is. This configuration provides a significant improvement in the detonation transmission conditions.
This paper was based on work that was partly presented at the International Conference on Combustion and Detonation, Zel’dovich Memorial II, Moscow, Russia, 30 August–3 September 2004, and at the 20th International Colloquium on the Dynamics of Explosions and Reactive systems, Montreal, Canada, 31 July–5 August 2005. 相似文献
This paper was based on work that was partly presented at the International Conference on Combustion and Detonation, Zel’dovich Memorial II, Moscow, Russia, 30 August–3 September 2004, and at the 20th International Colloquium on the Dynamics of Explosions and Reactive systems, Montreal, Canada, 31 July–5 August 2005. 相似文献
959.
Alan R. Katritzky Boris V. Rogovoy Christophe Chassaing Vladimir Vvedensky Behrouz Forood Brenton Flatt Hisao Nakai 《Journal of heterocyclic chemistry》2000,37(6):1655-1658
The condensation of α,β‐unsaturated ketones with substituted o‐aminothiophenols, obtained by reductive cleavage of the corresponding disulfides in the presence of triphenylphosphine, is an effective method for the synthesis of 2,4‐diaryl‐2,3‐dihydro‐1,5‐benzothiazepines under neutral conditions. 相似文献
960.
Neven Strukan Marina Cindri Tanja Kajfe Boris Kamenar Gerald Giester 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):e443-e444
The crystal and molecular structure of bis(tetramethylammonium) dichlorotetra‐μ2‐methoxo‐di‐μ2‐oxo‐octooxotetramolybdate(VI), (C4H12N)2[Mo4O10(OCH3)4Cl2], has been determined from X‐ray diffraction data. The crystallographically centrosymmetric anion is built up of four edge‐sharing octahedra, two MoO6 and two MoO5Cl. 相似文献