3,562 research outputs found
Self-Organization of Vortex Length Distribution in Quantum Turbulence: An Approach from the Barabasi-Albert Model
The energy spectrum of quantum turbulence obeys Kolmogorov's law. The vortex
length distribution (VLD), meaning the size distribution of the vortices, in
Kolmogorov quantum turbulence also obeys a power law. We propose here an
innovative idea to study the origin of the power law of the VLD. The nature of
quantized vortices allows one to describe the decay of quantum turbulence with
a simple model that is similar to the Barabasi-Albert model of large networks.
We show here that such a model can reproduce the power law of the VLD well.Comment: 4 pages including 5 figure
A Kelvin-wave cascade on a vortex in superfluid He at a very low temperature
A study by computer simulation is reported of the behaviour of a quantized
vortex line at a very low temperature when there is continuous excitation of
low-frequency Kelvin waves. There is no dissipation except by phonon radiation
at a very high frequency. It is shown that non-linear coupling leads to a net
flow of energy to higher wavenumbers and to the development of a simple
spectrum of Kelvin waves that is insensitive to the strength and frequency of
the exciting drive. The results are likely to be relevant to the decay of
turbulence in superfluid He at very low temperatures
Kondo-like behaviors in magnetic and thermal properties of single crystal Tm5Si2Ge2
We grew the single crystal of stoichiometric Tm5Si2.0Ge2.0 using a Bridgeman
method and performed XRD, EDS, magnetization, ac and dc magnetic
susceptibilities, specific heat, electrical resistivity and XPS experiments. It
crystallizes in orthorhombic Sm5Ge4-type structure. The mean valence of Tm ions
in Tm5Si2.0Ge2.0 is almost trivalent. The 4f states is split by the crystalline
electric field. The ground state exhibits the long range antiferromagnetic
order with the ferromagnetically coupled magnetic moments in the ac plane below
8.01 K, while the exited states exhibit the reduction of magnetic moment and
magnetic entropy and -log T-behaviors observed in Kondo materials.Comment: 8 pages, 13 figure
Sistema Web para estimativas de perdas por seca na cultura da soja.
bitstream/item/71974/1/ID-30954.pd
Soybean gene express: plataforma para análise de expressão diferencial e bibliotecas substrativas de cDNA.
bitstream/item/71550/1/ID-30973.pd
Nature of the insulating phases in the half-filled ionic Hubbard model
We investigate the ground-state phase diagram of the one-dimensional "ionic"
Hubbard model with an alternating periodic potential at half-filling by
numerical diagonalization of finite systems with the Lanczos and density matrix
renormalization group (DMRG) methods. We identify an insulator-insulator phase
transition from a band to a correlated insulator with simultaneous charge and
bond-charge order. The transition point is characterized by the vanishing of
the optical excitation gap while simultaneously the charge and spin gaps remain
finite and equal. Indications for a possible second transition into a
Mott-insulator phase are discussed.Comment: final for
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