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991.
992.
We use Hanbury-Brown-Twiss interferometry (HBTI) to study various quantum phases of hard core bosons (HCBs) and ideal fermions confined in a one-dimensional quasi-periodic (QP) potential. For HCBs, the QP potential induces a cascade of Mott-like band-insulator phases in the extended regime, in addition to the Mott insulator, Bose glass, and superfluid phases. At critical filling factors, the appearance of these insulating phases is heralded by a peak to dip transition in the interferogram, which reflects the fermionic aspect of HCBs. On the other hand, ideal fermions in the extended phase display various complexities of incommensurate structures such as devil’s staircases and Arnold tongues. In the localized phase, the HCB and the fermion correlations are identical except for the sign of the peaks. Finally, we demonstrate that HBTI provides an effective method to distinguish Mott and glassy phases. 相似文献
993.
L. Fortunato R. M. Clark A. O. Macchiavelli R. Krücken 《The European physical journal. Special topics》2007,150(1):107-108
The critical point solution of the pairing phase transition
from vibrational to rotational regimes and an application to lead isotopes
are described. Suggestions on how to confirm the validity of the E(2) model
with transfer reactions using weakly-bound beams are discussed. 相似文献
994.
995.
996.
997.
998.
Recent papers on chevron surface stabilized ferroelectric liquid crystal cells claim that the chevron layer structure can be reversibly uprighted by application of the low to moderate electric fields typically employed to produce director reorientation. In this paper we show, using optical microscopy and X-ray scattering, that there is no significant change in the smectic layer thickness or chevron layer structure of our chevron surface stabilized ferroelectric liquid crystal cells under typical director switching conditions. Furthermore, we present arguments, based on the known elastic properties of smectics, that there is not likely to be a significant elastic layer response to these levels of applied electric field in any surface stabilized ferroelectric liquid crystal cell with anchored layers. Both the switching and observed continuous optical response to applied field can be understood on the basis of electric field induced reorientation of a non-uniform molecular director distribution. We further show that the typically observed broad distribution of layer orientations about the mean chevron structure arises from localized layering defects. 相似文献
999.
F.G. Kondev M.A. Riley T.B. Brown R.M. Clark M. Devlin P. Fallon D.J. Hartley I.M. Hibbert D.T. Joss D.R. LaFosse R.W. Laird F. Lerma M. Lively P.J. Nolan N.J. O'Brien E.S. Paul J. Pfohl D.G. Sarantites R.K. Sheline S.L. Shepherd J. Simpson R. Wadsworth 《The European Physical Journal A - Hadrons and Nuclei》1998,2(3):249-251
The quadrupole moment for the πg
9/2⊗νh
11/2 band in the 130>Pr nucleus has been measured using the Doppler-shift attenuation method. A centroid shift analysis was carried out and a value
of Q0=6.1±0.4 eb, corresponding to an axial prolate deformation of β2=0.35(3), has been determined. This is the first direct experimental confirmation of the deformation-driving character of
the πg
9/2 orbital in an odd-odd nucleus in the A≃135 superdeformed region.
Received: 23 April 1998 相似文献
1000.
Joint rolling-horizon scheduling of materials processing and lot-sizing with sequence-dependent setups 总被引:3,自引:0,他引:3
A lot sizing and scheduling problem from a foundry is considered in which key materials are produced and then transformed
into many products on a single machine. A mixed integer programming (MIP) model is developed, taking into account sequence-dependent
setup costs and times, and then adapted for rolling horizon use. A relax-and-fix (RF) solution heuristic is proposed and computationally
tested against a high-performance MIP solver. Three variants of local search are also developed to improve the RF method and
tested. Finally the solutions are compared with those currently practiced at the foundry. 相似文献