6,800 research outputs found
Microscopic description of -photoproduction on light nuclei
A microscopic four-body description of near-threshold coherent
photoproduction of the meson on the (3N)-nuclei is given. The
photoproduction cross-section is calculated using the Finite Rank Approximation
(FRA) of the nuclear Hamiltonian. The results indicate that the final state
interaction of the meson with the residual nucleus plays an important
role in the photoproduction process. Sensitivity of the results to the choice
of the T-matrix is investigated. The importance of obeying the
condition of unitarity is demonstrated.Comment: 4 pages, 4 figures; talk given at the International Conference on
Mesons and Light Nuclei '01, Prague, Czech Republic, July 2-6, 2001; to be
published in the Proceedings (AIP press
Luttinger Liquid in the Core of Screw Dislocation in Helium-4
On the basis of first-principle Monte Carlo simulations we find that the
screw dislocation along the hexagonal axis of an hcp He4 crystal features a
superfluid core. This is the first example of a regular quasi-one-dimensional
supersolid, and one of the cleanest cases of a regular Luttinger-liquid system.
In contrast, the same type of screw dislocation in solid Hydrogen is
insulating.Comment: replaced with revised versio
Stress induced dislocation roughening -- phase transition in 1d at finite temperature
We present an example of a generically forbidden phase transition in 1d at
finite temperature -- stress induced and thermally assisted roughening of a
superclimbing dislocation in a Peierls potential. We also argue that such
roughening is behind the strong suppression of the superflow through solid \he4
in a narrow temperature range recently observed by Ray and Hallock (Phys.Rev.
Lett. {\bf 105}, 145301 (2010)).Comment: 4 revtex pages, 5 figures. Replaced with the published versio
The role of Helium-3 impurities in the stress induced roughening of superclimbing dislocations in solid Helium-4
We analyze the stress induced and thermally assisted roughening of a forest
of superclimbing dislocations in a Peierls potential in the presence of
Helium-3 impurities and randomly frozen in static stresses. It is shown that
the temperature of the dip in the flow rate observed by Ray and Hallock
(Phys.Rev. Lett. {\bf 105}, 145301 (2010)) is determined by the energy of the
impurity activation from dislocation core. However, it is suppressed by,
essentially, the logarithm of the impurity fraction. The width of the dip is
determined by inhomogeneous fluctuations of the stresses and is shown to be
much smaller than .Comment: Submitted to the LT26-conference proceeding
ALGORITHM OF FORMATION OF MARKETING STRATEGY OF THE TOURIST ENTERPRISE
In the tourism industry, we can state a certain freedom of strategic choice: to pursue limited or broad marketing goals, to use the competitive advantages of low costs or their differentiation. Some of the approaches can be used simultaneously. It should be noted, however, that the set of strategic capabilities of the tourism organization is limited by the capabilities of the industry and the conditions of competition in it, the competitiveness of the organization, its market position and capabilities. The main tasks in determining the starting point for the formation of strategies are the choice of key areas and their relationship with other aspects of organizational management (marketing, finance, current management, etc.)
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