2,030 research outputs found
Bosonic molecules in rotating traps
We present a variational many-body wave function for repelling bosons in
rotating traps, focusing on rotational frequencies that do not lead to
restriction to the lowest Landau level. This wave function incorporates
correlations beyond the Gross-Pitaevskii (GP) mean field approximation, and it
describes rotating boson molecules (RBMs) made of localized bosons that form
polygonal-ring-like crystalline patterns in their intrinsic frame of reference.
The RBMs exhibit characteristic periodic dependencies of the ground-state
angular momenta on the number of bosons in the polygonal rings. For small
numbers of neutral bosons, the RBM ground-state energies are found to be always
lower than those of the corresponding GP solutions, in particular in the regime
of GP vortex formation.Comment: To appear in Phys. Rev. Lett. LATEX, 5 pages with 5 figures. For
related papers, see http://www.prism.gatech.edu/~ph274cy
Medical card of a pulmonary tuberculosis in-patient
ИСТОРИЯ БОЛЕЗНИОБСЛЕДОВАНИЕ БОЛЬНОГОТУБЕРКУЛЕЗ ЛЕГКИХУЧЕБНО-МЕТОДИЧЕСКИЕ ПОСОБИЯФТИЗИОПУЛЬМОНОЛОГИЯУчебно-методическое пособие предназначено для самостоятельной подготовки к курации больных в клинике и написанию учебной истории болезни
Crystalline boson phases in harmonic traps: Beyond the Gross-Pitaevskii mean field
Strongly repelling bosons in two-dimensional harmonic traps are described
through breaking of rotational symmetry at the Hartree-Fock level and
subsequent symmetry restoration via projection techniques, thus incorporating
correlations beyond the Gross-Pitaevskii (GP) solution. The bosons localize and
form polygonal-ring-like crystalline patterns, both for a repulsive contact
potential and a Coulomb interaction, as revealed via
conditional-probability-distribution analysis. For neutral bosons, the total
energy of the crystalline phase saturates in contrast to the GP solution, and
its spatial extent becomes smaller than that of the GP condensate. For charged
bosons, the total energy and dimensions approach the values of classical
point-like charges in their equilibrium configuration.Comment: Published version. Typos corrected. REVTEX4; 5 pages with 3 PS
figures. For related papers, see http://www.prism.gatech.edu/~ph274c
The form factors from Analyticity and Unitarity
Analyticity and unitarity techniques are employed to obtain bounds on the
shape parameters of the scalar and vector form factors of semileptonic
decays. For this purpose we use vector and scalar correlators evaluated in
pQCD, a low energy theorem for scalar form factor, lattice results for the
ratio of kaon and pion decay constants, chiral perturbation theory calculations
for the scalar form factor at the Callan-Treiman point and experimental
information on the phase and modulus of form factors up to an energy
\tin=1 {\rm GeV}^2. We further derive regions on the real axis and in the
complex-energy plane where the form factors cannot have zeros.Comment: 6 pages, 5 figures; Seminar given at DAE-BRNS Workshop on Hadron
Physics Bhabha Atomic Research Centre, Mumbai, India October 31-November 4,
2011, submitted to Proceeding
Seasonal abundance of small cladocerans in Lake Mangakaware, Waikato, New Zealand
The seasonal changes in the dynamics and life histories of the Cladocera in Lake Mangakaware, North Island, New Zealand, were studied over 19 months by sampling at weekly or 2-weekly intervals. Lake Mangakaware is a 13.3 ha polymictic lake with high nutrient status, low Secchi disc transparencies, and an unstable thermal regime. The four planktonic cladoceran species (Bosmina longirostris, B. meridionalis, Ceriodaphnia pulchella, and C. dubia) exhibited disjunct population maxima. Only B. longirostris was perennially present. All species exhibited low fecundities and low lipid content, indicating that food resources were limited and that competitive interactions and resistance to starvation were probably important in determining species success. Increases in body size in cooler seasons were unrelated to clutch size, giving further support for the view that available food was limited. These results are consistent with previous experimental findings that subtle differences in life history can determine seasonal success and the outcome of competition between similar species
Study of He+C Elastic Scattering Using a Microscopic Optical Potential
The He+C elastic scattering data at beam energies of 3, 38.3 and
41.6 MeV/nucleon are studied utilizing the microscopic optical potentials
obtained by a double-folding procedure and also by using those inherent in the
high-energy approximation. The calculated optical potentials are based on the
neutron and proton density distributions of colliding nuclei established in an
appropriate model for He and obtained from the electron scattering form
factors for C. The depths of the real and imaginary parts of the
microscopic optical potentials are considered as fitting parameters. At low
energy the volume optical potentials reproduce sufficiently well the
experimental data. At higher energies, generally, additional surface terms
having form of a derivative of the imaginary part of the microscopic optical
potential are needed. The problem of ambiguity of adjusted optical potentials
is resolved requiring the respective volume integrals to obey the determined
dependence on the collision energy. Estimations of the Pauli blocking effects
on the optical potentials and cross sections are also given and discussed.
Conclusions on the role of the aforesaid effects and on the mechanism of the
considered processes are made.Comment: 12 pages, 9 figures, accepted for publication in Physical Review
Calculations of He+p Elastic Cross Sections Using Microscopic Optical Potential
An approach to calculate microscopic optical potential (OP) with the real
part obtained by a folding procedure and with the imaginary part inherent in
the high-energy approximation (HEA) is applied to study the He+p elastic
scattering data at energies of tens of MeV/nucleon (MeV/N). The neutron and
proton density distributions obtained in different models for He are
utilized in the calculations of the differential cross sections. The role of
the spin-orbit potential is studied. Comparison of the calculations with the
available experimental data on the elastic scattering differential cross
sections at beam energies of 15.7, 26.25, 32, 66 and 73 MeV/N is performed. The
problem of the ambiguities of the depths of each component of the optical
potential is considered by means of the imposed physical criterion related to
the known behavior of the volume integrals as functions of the incident energy.
It is shown also that the role of the surface absorption is rather important,
in particular for the lowest incident energies (e.g., 15.7 and 26.25
MeV/nucleon).Comment: 11 pages, 7 figures, accepted for publication in Physical Review
Permafrost degradation risk zone assessment using simulation models
In this proof-of-concept study we focus on linking large scale climate and permafrost simulations to small scale engineering projects by bridging the gap between climate and permafrost sciences on the one hand and on the other technical recommendation for adaptation of planned infrastructures to climate change in a region generally underlain by permafrost. We present the current and future state of permafrost in Greenland as modelled numerically with the GIPL model driven by HIRHAM climate projections up to 2080. We develop a concept called Permafrost Thaw Potential (PTP), defined as the potential active layer increase due to climate warming and surface alterations. PTP is then used in a simple risk assessment procedure useful for engineering applications. The modelling shows that climate warming will result in continuing wide-spread permafrost warming and degradation in Greenland, in agreement with present observations. We provide examples of application of the risk zone assessment approach for the two towns of Sisimiut and Ilulissat, both classified with high PTP
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