2,043 research outputs found
Minimizing the linewidth of the Flux-Flow Oscillator
For the first time the linewidth of Flux-Flow Oscillator has been calculated
by direct computer simulation of the sine-Gordon equation with noise. Nearly
perfect agreement of the numerical results with the formula derived in [Phys.
Rev. B, {\bf 65}, 054504 (2002)] has been achieved. It has been demonstrated
that for homogeneous bias current distribution the linewidth actually does not
depend on the junction length for practically interesting parameters range.
Depending on the length of the unbiased tail, the power may be maximized and
the linewidth may be minimized in a broad range of bias currents. The linewidth
can be decreased further by 1.5 times by proper load matching.Comment: 4 pages, 6 figure
Greater role of depreciation in innovative development of construction business production potential
The paper discusses current status of capital assets for construction, and proposes methods and ways to make depreciation more important in related reproduction investment processes
New non-equilibrium matrix imbibition equation for Kondaurov's double porosity model
The paper deals with the global Kondaurov double porosity model describing a
non-equilibrium two-phase immiscible flow in fractured-porous reservoirs when
non-equilibrium phenomena occur in the matrix blocks, only. It is shown that
the homogenized model can be represented as usual equations of two-phase
incompressible immiscible flow, except for the addition of two source terms
calculated by a solution to a local problem which is a boundary value problem
for a non-equilibrium imbibition equation given in terms of the real saturation
and a non-equilibrium parameter.Comment: 11 pages, 1 figur
Time-dependent occupation numbers in reduced-density-matrix functional theory: Application to an interacting Landau-Zener model
We prove that if the two-body terms in the equation of motion for the
one-body reduced density matrix are approximated by ground-state functionals,
the eigenvalues of the one-body reduced density matrix (occupation numbers)
remain constant in time. This deficiency is related to the inability of such an
approximation to account for relative phases in the two-body reduced density
matrix. We derive an exact differential equation giving the functional
dependence of these phases in an interacting Landau-Zener model and study their
behavior in short- and long-time regimes. The phases undergo resonances
whenever the occupation numbers approach the boundaries of the interval [0,1].
In the long-time regime, the occupation numbers display correlation-induced
oscillations and the memory dependence of the functionals assumes a simple
form.Comment: 6 pages, revised, Fig. 2 adde
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