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41.
Francesco D’Andrea Gaetano Fiore Davide Franco 《Letters in Mathematical Physics》2014,104(11):1425-1443
Using the Weil–Brezin–Zak transform of solid state physics, we describe line bundles over elliptic curves in terms of Weyl operators. We then discuss the connection with finitely generated projective modules over the algebra A θ of the noncommutative torus. We show that such A θ -modules have a natural interpretation as Moyal deformations of vector bundles over an elliptic curve E τ , under the condition that the deformation parameter θ and the modular parameter τ satisfy a non-trivial relation. 相似文献
42.
We demonstrate a high-power, narrowband pulsed source at 390 nm by two stages of frequency doubling in periodically poled MgO:LiNbO(3) and periodically poled KTiOPO(4) of an amplified, passively mode-locked fiber laser. With a frequency quadrupling efficiency of 5.5% and a 0.1 nm bandwidth, the 250 mW ultraviolet source is a suitable compact pump source for many entanglement-based quantum information processing tasks. 相似文献
43.
R. Lo Franco G. Compagno A. Messina A. Napoli 《The European physical journal. Special topics》2008,160(1):247-257
We show that the N-photon generalized binomial states of electromagnetic field may be put in a bijective mapping with the
coherent atomic states of N two-level atoms. We exploit this correspondence to simply obtain both known and new properties
of the N-photon generalized binomial states. In particular, an over-complete basis of these binomial states and an orthonormal
basis are obtained. Finally, the squeezing properties of generalized binomial state are analyzed. 相似文献
44.
Gulevich DR Kusmartsev FV Savel'ev S Yampol'skii VA Nori F 《Physical review letters》2008,101(12):127002
We predict a new class of excitations propagating along a Josephson vortex in two-dimensional Josephson junctions. These excitations are associated with the distortion of a Josephson vortex line and have an analogy with shear waves in solid mechanics. Their shapes can have an arbitrary profile, which is retained when propagating. We derive a universal analytical expression for the energy of arbitrary shape excitations, investigate their influence on the dynamics of a vortex line, and discuss conditions where such excitations can be created. Finally, we show that such excitations play the role of a clock for a relativistically moving Josephson vortex and suggest an experiment to measure a time dilation effect analogous to that in special relativity. 相似文献
45.
Fulvio Ratto Paolo Matteini Alberto Cini Sonia Centi Francesca Rossi Franco Fusi Roberto Pini 《Journal of nanoparticle research》2011,13(9):4337-4348
We investigate the photothermal conversion and transformation of gold nanoparticles with an initial dogbone shape after dispersion in hydrated chitosan films, which is a representative model of biological tissue, and excitation by a CW diode laser for 1 min. Gold nanodogbones are observed to undergo a distinct modification above a sharp threshold of ~11 W cm−2 and 110 °C. Surprisingly, the very same modification is achieved up to at least 36 W cm−2 and 250 °C. We use an analytical model derived from Gans theory to associate the change in color of the films with the change in shape statistics of these gold nanoparticles. This model proves both convenient and dependable. We interpret the photothermal transformation as a rearrangement of particles with a dogbone shape and an aspect ratio of 4.1 into rods with an aspect ratio of 2.5, where material from the end lobes of the dogbones may relocate to the waists of the rods. In turn, additional transitions to stable gold nanospheres may exhibit fairly slower kinetics. 相似文献
46.
Abe Y Aberle C Akiri T dos Anjos JC Ardellier F Barbosa AF Baxter A Bergevin M Bernstein A Bezerra TJ Bezrukhov L Blucher E Bongrand M Bowden NS Buck C Busenitz J Cabrera A Caden E Camilleri L Carr R Cerrada M Chang PJ Chimenti P Classen T Collin AP Conover E Conrad JM Cormon S Crespo-Anadón JI Cribier M Crum K Cucoanes A D'Agostino MV Damon E Dawson JV Dazeley S Dierckxsens M Dietrich D Djurcic Z Dracos M Durand V Efremenko Y Elnimr M Endo Y Etenko A Falk E Fallot M Fechner M von Feilitzsch F 《Physical review letters》2012,108(13):131801
The Double Chooz experiment presents an indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. An observed-to-predicted ratio of events of 0.944±0.016(stat)±0.040(syst) was obtained in 101 days of running at the Chooz nuclear power plant in France, with two 4.25 GW(th) reactors. The results were obtained from a single 10 m(3) fiducial volume detector located 1050 m from the two reactor cores. The reactor antineutrino flux prediction used the Bugey4 flux measurement after correction for differences in core composition. The deficit can be interpreted as an indication of a nonzero value of the still unmeasured neutrino mixing parameter sin(2)2θ(13). Analyzing both the rate of the prompt positrons and their energy spectrum, we find sin(2)2θ(13)=0.086±0.041(stat)±0.030(syst), or, at 90% C.L., 0.017相似文献
47.
Eduardo de Almeida Paulo Rogério Massoni Amauri Antonio Menegário Laudi Cunha Leite Dante Pazzanese Duarte Lanna Virgílio Franco do Nascimento Filho 《X射线光谱测定》2011,40(6):424-426
This article describes a comparison of conventional energy‐dispersive X‐ray fluorescence (EDXRF) and synchrotron radiation total‐reflection X‐ray fluorescence (SRTXRF) for Co determination in ruminal fluid from Holstein cow. This element is used as marker for animal nutrition studies. For EDXRF, 200 µl of the sample were dried on 6.35 µm Mylar film at 60 °C. The excitation was carried out using an X‐ray tube with Mo target and Zr filter operated at 30 kV/20 mA. For SRTXRF, 10 µl of the sample were pipetted on a Lucite carrier and dried at 60 °C. In both the techniques, Ga was used as internal standard and the acquisition time was 200 s. The trueness of both techniques was evaluated through the standard addition method, the recoveries obtained by SRTXRF and EDXRF were 76 and 99%, and the limits of detection, 13 and 240 µg l?1, respectively. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
48.
Acetyl derivatives of alcoholic and phenolic hydroxyl groups represent not only useful educts, intermediates and products in organic, bioorganic and pharmaceutical chemistry, but also interesting derivatives for isolation, purification and characterization of alcohols and phenols (especially for natural products). Furthermore, the acetylation reaction is frequently used for the protection of hydroxyl function. In general, however, acetoxy-groups may be highly resistent to hydrolysis so that their conversion into hydroxyl groups often requires strongly basic or acidic media, expensive and/or hardly available reagents, complicated procedures. These conditions may be incompatible with sensitive substrates or with other insufficiently stable groups present in the molecular residue.1,2 Very similar arguments are sound for some hydrazide derivatives of carboxylic acids.1,3,4 相似文献
49.
Franco Cristiani Francesco A. Devillanova Angelo Diaz Francesco Isaia Gaetano Verani 《Heteroatom Chemistry》1990,1(5):363-367
Using a series of N-methylated thiohydantoins as substrates, the donor properties of the sulfur atom are measured by determining the stability constants (K) of their adducts with molecular iodine. The K's have been determined by recording the UV-visible spectra of several CH2Cl2 solutions with different amounts of the reagents. The experimental data fit the 1:1 adduct model for all the compounds. The K values, compared with those previously found for the unsubstituted hydantoins and with those obtained for 5-methyl-2-thiohydantoin, show that the hydrogen-bonding interaction between the NH hydrogen and the S-bonded iodine plays an important role in determining the stability of the adduct. The K values obtained for several pentaatomic rings, all containing the thioureido group HN C() NH , are discussed on the basis of the influence of the substituents at C-4 and C-5 on the donor properties of the sulfur atom. 相似文献
50.
Merlin C. E. Bandeira César V. Franco Emilse Martini 《Journal of Solid State Electrochemistry》1999,3(4):210-214
The present study focuses on the electronic and electrochemical features of a copolymer electrochemically grown from pyrrole
and trans-[RuCl2(pmp)4] monomers, where pmp = 3-(pyrrol-1-ylmethyl)pyridine. The results from electrochemical impedance spectroscopy analyses revealed
the redox behavior of the poly{pyrrole-trans-[RuCl2(pmp)4]} compound as well as the non-homogeneous nature of the extremely thin polymeric layers. An equivalent circuit is proposed
for an optimized film produced under the scope of the work.
Received: 4 May 1998 / Accepted: 24 August 1998 相似文献