53 research outputs found
Оценка эффективности применения полимерного заводнения на месторождении Х
Обоснован выбор полимерного заводнения, как метод увеличения нефтеотдачи пласта на Северо-Хохряковском месторождении;
Выбран химический реагент для проведения полимерного заводнения на месторождении;
Обоснована возможность проведения полимерного заводнения на выбранном продуктивном пласте посредством технико-экономических расчетов.The choice of polymer flooding as a method to increase oil recovery in the Severo-Khokhryakovskoye field was justified;
Chemical reagent was selected for polymer flooding in the field;
The possibility of carrying out polymer flooding in the selected productive formation by means of technical and economic calculations was substantiated
Berry's Phase in the Presence of a Dissipative Medium
We consider the spin 1/2 model coupled to a slowly varying magnetic field in
the presence of a weak damping represented by a Lindblad-form operators. We
show that Berry's geometrical phase remains unaltered by the two dissipation
mechanism considered. Dissipation effects are twofold: a shrinking in the
modulus of the Bloch's vector, which characterizes coherence loss and a time
dependent (dissipation related) precession angle. We show that the line
broadening of the Fourier transformation of the components of magnetization is
only due to the presence of dissipation.Comment: 19 pages, 2 figure
Some applications of the Faddeev-Yakubovsky equations to the cold-atom physics
We present some recent applications of the Faddeev--Yakubovsky equations in
describing atomic bound and scattering problems. We consider the scattering of
a charged particle by atomic hydrogen with special interest in
, systems of cold bosonic molecules and the bound and scattering
properties of N=3 and N=4 atomic He multimers
Adiabatic Approximation in the Density Matrix Approach: Non-Degenerate Systems
We study the adiabatic limit in the density matrix approach for a quantum
system coupled to a weakly dissipative medium. The energy spectrum of the
quantum model is supposed to be non-degenerate. In the absence of dissipation,
the geometric phases for periodic Hamiltonians obtained previously by M.V.
Berry are recovered in the present approach. We determine the necessary
condition satisfied by the coefficients of the linear expansion of the
non-unitary part of the Liouvillian in order to the imaginary phases acquired
by the elements of the density matrix, due to dissipative effects, be
geometric. The results derived are model-independent. We apply them to spin 1/2
model coupled to reservoir at thermodynamic equilibrium.Comment: 24 pages (new version), accepted for publication in Physica
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Faddeev calculations of p{mu}+p collisions: Effect of hyperfine splitting on the cross sections
The Faddeev equations, modified to remove long-range coupling between different channels, are solved in the total-angular-momentum representation for p{mu} + p collisions. S-wave elastic and hyperfine-transition cross sections are calculated with and without explicit inclusion of the hyperfine splitting {Delta}E. For hyperfine quenching the simpler approach without hyperfine splitting is found adequate at collision energies above about {Delta}E, but for elastic scattering it becomes adequate at somewhat higher energies. The present cross sections tend to fall in between earlier calculations done using a large Standard adiabatic expansion and those done using a two-state improved adiabatic expansion, but are closer to the former
Three-potential formalism for the three-body scattering problem with attractive Coulomb interactions
A three-body scattering process in the presence of Coulomb interaction can be
decomposed formally into a two-body single channel, a two-body multichannel and
a genuine three-body scattering. The corresponding integral equations are
coupled Lippmann-Schwinger and Faddeev-Merkuriev integral equations. We solve
them by applying the Coulomb-Sturmian separable expansion method. We present
elastic scattering and reaction cross sections of the system both below
and above the threshold. We found excellent agreements with previous
calculations in most cases.Comment: 12 pages, 3 figure
Pseudo-Supersymmetric Quantum Mechanics and Isospectral Pseudo-Hermi tian Hamiltonians
We examine the properties and consequences of pseudo-supersymmetry for
quantum systems admitting a pseudo-Hermitian Hamiltonian. We explore the Witten
index of pseudo-supersymmetry and show that every pair of diagonalizable (not
necessarily Hermitian) Hamiltonians with discrete spectra and real or
complex-conjugate pairs of eigenvalues are isospectral and have identical
degeneracy structure except perhaps for the zero eigenvalue if and only if they
are pseudo-supersymmetric partners. This implies that pseudo-supersymmetry is
the basic framework for generating non-Hermitian PT-symmetric and
non-PT-symmetric Hamiltonians with a real spectrum via a Darboux
transformation, and shows that every diagonalizable Hamiltonian H with a
discrete spectrum and real or complex-conjugate pairs of eigenvalues may be
factored as H=L^# L where L is a linear operator with pseudo-adjoint L^#. In
particular, this factorization applies to PT-symmetric and Hermitian
Hamiltonians. The nondegenerate two-level systems provide a class of
Hamiltonians that are pseudo-Hermitian. We demonstrate the implications of our
general results for this class in some detail.Comment: Minor corrections, accepted for publication in Nucl. Phys.
Electron-hydrogen scattering in Faddeev-Merkuriev integral equation approach
Electron-hydrogen scattering is studied in the Faddeev-Merkuriev integral
equation approach. The equations are solved by using the Coulomb-Sturmian
separable expansion technique. We present - and -wave scattering and
reactions cross sections up to the threshold.Comment: 2 eps figure
Elite opinion and foreign policy in post-communist Russia
Russian elite opinion on matters of foreign policy may be classified as ‘Liberal Westerniser’, ‘Pragmatic Nationalist’ and ‘Fundamentalist Nationalist’, terms that reflect longstanding debates about the country’s relationship with the outside world. An analysis of press
statements and election manifestoes together with a programme of elite interviews between 2004 and 2006 suggests a clustering of opinion on a series of strategic issues. Liberal Westernisers seek the closest possible relationship with Europe, and favour eventual membership of the EU and NATO. Pragmatic Nationalists are more inclined to favour practical co-operation, and do not assume an identity of values or interests with the Western countries. Fundamentalist Nationalists place more emphasis on the other former Soviet republics, and on Asia as much as Europe, and see the West as a threat to Russian values as well as to its state interests. Each of these positions,
in turn, draws on an identifiable set of domestic constituencies: Liberal Westernisers on the promarket political parties, Pragmatic Nationalists on the presidential administration and defence and security ministries, and Fundamentalist Nationalists on the Orthodox Church and Communists
Accidental Degeneracy and Berry Phase of Resonant States
We study the complex geometric phase acquired by the resonant states of an
open quantum system which evolves irreversibly in a slowly time dependent
environment. In analogy with the case of bound states, the Berry phase factors
of resonant states are holonomy group elements of a complex line bundle with
structure group C*. In sharp contrast with bound states, accidental
degeneracies of resonances produce a continuous closed line of singularities
formally equivalent to a continuous distribution of "magnetic" charge on a
"diabolical" circle, in consequence, we find different classes of topologically
inequivalent non-trivial closed paths in parameter space.Comment: 23 pages, 2 Postscript figures, LaTex, to be published in: Group 21:
Symposium on Semigroups and Quantum Irreversibility (Proc. of the XXI Int.
Colloquium on Group Theoretical Methods in Physics
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