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71.
C. Fabre U. Andersen H. Bachor B. Buchler S. Gigan P. K. Lam A. Maître N. Treps 《Superlattices and Microstructures》2002,32(4-6)
Optical images can be used to transport, store and process information in a parallel way. We discuss different results obtained in the domain of ‘quantum imaging’, aiming at exploiting at the same time the quantum properties of optical images and their intrinsic parallelism. We define the notion of standard quantum limit (SQL) in optical resolution, set by the quantum noise of usual coherent light, and show that it can be much lower than the diffraction limit. We also prove that this limit can be circumvented by especially designed nonclassical and multimode light. We present an experiment showing that OPOs oscillating inside an exactly confocal cavity actually produce such transverse multimode nonclassical light. We finally describe another experiment which has surpassed the SQL in the case of beam positioning, both in the 1D and 2D cases. 相似文献
72.
73.
U. Weisbrod R. Gutschke J. Knoth H. Schwenke 《Fresenius' Journal of Analytical Chemistry》1991,341(1-2):83-86
Summary Single layers and layer systems on diverse substrates were measured by Total Reflection X-Ray Fluorescence (TXRF) spectrometry. The angular dependence of the fluorescence intensities at grazing incidence allows the elemental composition, density and thickness of the layers to be evaluated using model calculations. 相似文献
74.
75.
We extend an earlier method for solving kinetic boundary layer problems to the case of particles moving in aspatially inhomogeneous background. The method is developed for a gas mixture containing a supersaturated vapor and a light carrier gas from which a small droplet condenses. The release of heat of condensation causes a temperature difference between droplet and gas in the quasistationary state; the kinetic equation describing the vapor is the stationary Klein-Kramers equation for Brownian particles diffusing in a temperature gradient. By means of an expansion in Burnett functions, this equation is transformed into a set of coupled algebrodifferential equations. By numerical integration we construct fundamental solutions of this equation that are subsequently combined linearly to fulfill appropriate mesoscopic boundary conditions for particles leaving the droplet surface. In view of the intrinsic numerical instability of the system of equations, a novel procedure is developed to remove the admixture of fast growing solutions to the solutions of interest. The procedure is tested for a few model problems and then applied to a slightly simplified condensation problem with parameters corresponding to the condensation of mercury in a background of neon. The effects of thermal gradients and thermodiffusion on the growth rate of the droplet are small (of the order of 1%), but well outside of the margin of error of the method. 相似文献
76.
S. A. J. Wiegers B. Tieke U. Zeitler R. Fletcher A. K. Geim J. C. Maan M. Henini 《Czechoslovak Journal of Physics》1996,46(5):2461-2462
We have investigated the interaction of phonons with a 2DEG in the FQH regime with phonon drag thermoelectric power (TEP). We find that the TEP at filling factors with the same even denominator is identical and at other even denominator filling factors they differ only by a constant. Assuming these states to be Composite Fermions (CF), we can explain our observations by extending a zero magnetic field theory for phonon drag to the CF-phonon interaction. This analysis is further corroborated by the observed T4 dependence of the CF TEP. 相似文献
77.
G. Baldsiefen H. Hübel W. Korten U. J. van Severen J. A. Cizewski N. H. Medina D. R. Napoli C. Rossi Alvarez G. Lo Bianco S. Signorelli 《Zeitschrift für Physik A Hadrons and Nuclei》1996,355(1):337-338
High-spin states in196Pb have been populated using the reaction170Er(30Si,4n). The previously observed shears bands in this nucleus have been extended and some of their transitions have been reordered. They now form regular bands with band crossings. One of the bands splits into two pathways at high spin. 相似文献
78.
79.
The1H and13C chemical shifts of 11 sparteine derivatives are reported. Substituent and group effects are interpreted in terms of structural properties. The conformational equilibrium of aphyllin is determined.Ruhr-Universität Bochum, Fakultät für Chemie, Bochum, Germany. Universität Hannover, Institut für Organische Chemie, Hannover, Germany (present address). Department of Organic Chemistry, Poznan Academy of Economics, Poznan, Poland. Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1026–1033, August, 1995. Original article submitted May 10, 1995.Dedicated to Prof. N. S. Zefirov on the occasion of his 60th birthday. 相似文献
80.
New Spiro Compounds from Cyclophosphazenes and Cyclodi[phosphadiazanes] Chlorocyclophosphazenes (Cl2P = N)3 and (Cl2p = N)4 react with dihydrazidophosphoric acid derivatives in THF in the presence of triethylamine to give the spirocyclic compounds Cl4N3P3(NHN(CH3))2P(S)OC6H5, Cl6N4P4(NHNH)2P(S)OC6H5. Constitutions have been confirmed by MS, NMR, IR and elemental analysis. 相似文献