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11.
J. C. Li J. Zhu Z. J. Peng 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(2):325-330
We study analytically and numerically the properties of one-dimensional
chain of cold ions placed in a periodic potential of optical lattice
and global harmonic potential of a trap.
In close similarity with the Frenkel-Kontorova model, a transition from
sliding to pinned phase takes place with the increase of
the optical lattice potential for the density of ions
incommensurate with the lattice period. We show that at zero temperature the quantum
fluctuations lead to a quantum phase transition
and melting of pinned instanton glass phase at large values of dimensional Planck constant.
After melting the ion chain can slide in an optical lattice.
The obtained results are also relevant for a Wigner crystal placed
in a periodic potential. 相似文献
12.
Efficiency Enhancement of Dye-Sensitized Solar Cells: Using Salt CuI as an Additive in an Ionic Liquid 下载免费PDF全文
Energy conversion efficiency of the dye-sensitized solar cell is improved from 3.5% to 4.5% by adding a small amount of CuI into an ionic liquid electrolyte. It is found that other copper-I salts, for example, CuBr, have the same effect for the dye-sensitized solar cell. Experimental results show that no Cu^2+ ions exist in this electrolyte. It is suggested that this improvement is caused by the adsorption of Cu^+ onto the TiO2 porous film. 相似文献
13.
We report on the fabrication of spectrally selective organic photodiodes (OPDs) and present a green sensitive OPD, whose spectral response peaks in the green region between 470 nm and 560 nm, as well as a red sensitive OPD whose spectral response peaks in the red region between 610 nm to 720 nm. We show that the spectral sensitivity of OPDs can be tuned by either choosing organic semiconductors with the appropriate photoresponse or by utilizing adequate device architectures with integrated optical filters. The results demonstrate the great flexibility of organic semiconductor materials. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
14.
H.?IidaEmail author M.?Oka H.?Suganuma 《The European Physical Journal A - Hadrons and Nuclei》2005,23(2):305-315
Dynamical chiral-symmetry breaking (DCSB) in QCD is investigated in the Schwinger-Dyson (SD) formalism based on lattice QCD data. From the quenched lattice data for the quark propagator in the Landau gauge, we extract the SD integral kernel function, the product of the quark-gluon vertex and the polarization factor in the gluon propagator, in an Ansatz-independent manner. We find that the SD kernel function exhibits the characteristic behavior of nonperturbative physics, such as infrared vanishing and strong enhancement at the intermediate-energy region around p 0.6GeV. The infrared and intermediate energy region (0.4GeV < p < 1.5GeV) is found to be most relevant for DCSB from analysis on the relation between the SD kernel and the quark mass function. We apply the lattice-QCD-based SD equation to thermal QCD, and calculate the quark mass function at the finite temperature. Spontaneously broken chiral symmetry is found to be restored at high temperature above 110 MeV. 相似文献
15.
Hopp B. Smausz T. Kresz N. Nagy P.M. Juhász A. Ignácz F. Márton Z. 《Applied Physics A: Materials Science & Processing》2003,76(5):731-735
Allergic-type diseases are current nowadays, and they are frequently caused by certain metals. We demonstrated that the metal
objects can be covered by Teflon protective thin layers using a pulsed laser deposition procedure. An ArF excimer laser beam
was focused onto the surface of pressed PTFE powder pellets; the applied fluences were 7.5–7.7 J/cm2. Teflon films were deposited on fourteen-carat gold, silver and titanium plates. The number of ablating pulses was 10000.
Post-annealing of the films was carried out in atmospheric air at oven temperatures between 320 and 500 °C. The thickness
of the thin layers was around 5 μm. The prepared films were granular without heat treatment or after annealing at a temperature
below 340 °C. At 360 °C a crystalline, contiguous, smooth, very compact and pinhole-free thin layer was produced; a melted
and re-solidified morphology was observed above 420 °C. The adhesion strength between the Teflon films and the metal substrates
was determined. This could exceed 1–4 MPa depending on the treatment temperature. It was proved that the prepared Teflon layers
can be suitable for prevention of contact between the human body and allergen metals and so for avoidance of metal allergy.
Received: 12 June 2002 / Accepted: 13 June 2002 / Published online: 4 November 2002
RID="*"
ID="*"Corresponding author. E-mail: bhopp@physx.u-szeged.hu 相似文献
16.
We employ QCD sum rules to calculate the coupling constant g by studying the three point -correlation function. Our result complements the analysis of this coupling constant utilizing the experimental value of the 00 decay rate studied within the framework of chiral perturbation theory including vector meson and meson intermediate states. 相似文献
17.
L. L. Salcedo 《EPJ direct》2001,3(1):1-10
In hadronic collisions, the mini-jet cross section is formally divergent in the limit
. We argue that this divergence is tamed by some effective colour correlation length scale of the hadron. A toy model of the hadronic structure is introduced, that allows an estimate of the screening effects, and especially their energy dependence. 相似文献
18.
S. Simula 《The European Physical Journal A - Hadrons and Nuclei》2007,31(4):603-605
We summarize the results of a recent global analysis of proton and deuteron F2 structure function world data performed over a large range of kinematics, including recent measurements done at JLab with
the CLAS detector. From these data the lowest moments (n≤10) of the unpolarized structure functions are determined with good statistics and systematics. The Q2 evolution of the extracted moments is analyzed in terms of an OPE-based twist expansion, taking into account soft-gluon effects
at large x. A clean separation among the leading- and higher-twist terms is achieved. By combining proton and deuteron measurements
the lowest moments of the neutron F2 structure function are determined and its leading-twist term is extracted. Particular attention is paid to nuclear effects
in the deuteron, which become increasingly important for the higher moments. Our results for the non-singlet, isovector (p-n) combination of the leading-twist moments are used to test recent lattice simulations. We also determine the lowest few moments
of the higher-twist contributions, and find these to be approximately isospin independent, suggesting the possible dominance
of ud correlations over uu and dd in the nucleon. 相似文献
19.
E. Ruiz Arriola W. Broniowski 《The European Physical Journal A - Hadrons and Nuclei》2007,31(4):739-741
Dimension-2 and -4 gluon condensates are re-analyzed in large-Nc Regge models with the ζ-function regularization which preserves the spectrum in any ˉq channel separately. We demonstrate that the signs and magnitudes of both condensates can be properly described within the
framework. 相似文献
20.
A. C. Aguilar J. Papavassiliou 《The European Physical Journal A - Hadrons and Nuclei》2007,31(4):742-745
The effective gluon propagator constructed with the pinch technique is governed by a Schwinger-Dyson equation with special
structure and gauge properties, that can be deduced from the correspondence with the background field method. Most importantly
the non-perturbative gluon self-energy is transverse order-by-order in the dressed loop expansion, and separately for gluonic
and ghost contributions, a property which allows for a meanigfull truncation. A linearized version of the truncated Schwinger-Dyson
equation is derived, using a vertex that satisfies the required Ward identity and contains massless poles. The resulting integral
equation, subject to a properly regularized constraint, is solved numerically, and the main features of the solutions are
briefly discussed. 相似文献