3,494 research outputs found
Resonances in Exotic He Nucleus within the No-Core Shell Model
We present ab initio calculations of resonances for He, a nucleus with no
bound states, using the realistic nucleon-nucleon interaction Daejeon16. For
this, we evaluate the elastic scattering phase shifts obtained
within an -matrix analysis of no-core shell model results for states in the
continuum. We predict new broad resonances likely related to fragmentary
experimental evidence.Comment: 6 pages, 3 figure
SS-HORSE Extension of the No-Core Shell Model: Application to Resonances in
Theoretical ab initio studies of resonances in the unbound
nucleus are presented. We perform no-core shell model calculations with
interactions Daejeon16 and JISP16 and utilize the SS-HORSE method to calculate
the matrix for two-body channels and
with respectively in the ground and excited
states as well as for the four-body democratic decay channel
. The resonant energies and widths areobtained by
numerical location of the -matrix poles. We describe all experimentally
known resonances and suggest an interpretation of an observed
wide resonance of unknown spin-parity.Comment: 10 pages, 2 figure
Stochastic theory of ferroelectric domain structure formation dominated by quenched disorder
A self-consistent stochastic model of domain structure formation in a
uniaxial ferroelectric, quenched from a high-temperature paraelectric phase to
a low-temperature ferroelectric phase, is developed with an account of the
applied electric field and the feedback effect via local depolarization fields.
Both polarization and field components are considered as Gauss random
variables. A system of integro-differential equations for correlation functions
of all involved variables is derived and solved analytically and numerically.
Phase diagram in terms of the average value and dispersion of polarization
reveals different possible equilibrium states and available final single-domain
and multi-domain states. The time-dependent evolution of the average
polarization and dispersion discloses a bifurcation behavior and the
temperature-dependent value of the electric field, deciding between the
single-domain and multi-domain final states, which can be interpreted as the
coercive field. Analytical and numerical results for the time-dependent
correlation length and correlation functions exhibit plausible agreement with
available experimental data.Comment: 33 pages, 10 figure
ВИКОРИСТАННЯ ПОТЕНЦІАЛУ ПРАКТИЧНОЇ ОХОРОНИ ЗДОРОВ’Я У ПІДГОТОВЦІ СУЧАСНОГО СПЕЦІАЛІСТА
The article adduces the main principles of students’ practical training organisation of Kremenets Medical College by Arsen Richynskyi, that are based on close cooperation of teachers and doctors. This cooperation provides a student with a complete picture about the future profession, helps to form professional, social and psychological competencies that are necessary for self-improvement and selfaffirmation in society.У статті висвітлено основні засади організації практичного тренування студентів Кременецького медичного училища імені Арсена Річинського, що основані на тісній співпраці викладачів училища та працівників практичної охорони здоров’я. Така співпраця дає студенту можливість отримати повне уявлення про майбутню професію, сформувати професійні, соціальні і психологічні компетенції, які необхідні для самореалізації, самовдосконалення і самоствердження в суспільстві
A Quantum Mechanical Model of the Reissner-Nordstrom Black Hole
We consider a Hamiltonian quantum theory of spherically symmetric,
asymptotically flat electrovacuum spacetimes. The physical phase space of such
spacetimes is spanned by the mass and the charge parameters and of the
Reissner-Nordstr\"{o}m black hole, together with the corresponding canonical
momenta. In this four-dimensional phase space, we perform a canonical
transformation such that the resulting configuration variables describe the
dynamical properties of Reissner-Nordstr\"{o}m black holes in a natural manner.
The classical Hamiltonian written in terms of these variables and their
conjugate momenta is replaced by the corresponding self-adjoint Hamiltonian
operator, and an eigenvalue equation for the ADM mass of the hole, from the
point of view of a distant observer at rest, is obtained. Our eigenvalue
equation implies that the ADM mass and the electric charge spectra of the hole
are discrete, and the mass spectrum is bounded below. Moreover, the spectrum of
the quantity is strictly positive when an appropriate self-adjoint
extension is chosen. The WKB analysis yields the result that the large
eigenvalues of the quantity are of the form , where
is an integer. It turns out that this result is closely related to
Bekenstein's proposal on the discrete horizon area spectrum of black holes.Comment: 37 pages, Plain TeX, no figure
Cosmological Dark Energy: Prospects for a Dynamical Theory
We present an approach to the problem of vacuum energy in cosmology, based on
dynamical screening of Lambda on the horizon scale. We review first the
physical basis of vacuum energy as a phenomenon connected with macroscopic
boundary conditions, and the origin of the idea of its screening by particle
creation and vacuum polarization effects. We discuss next the relevance of the
quantum trace anomaly to this issue. The trace anomaly implies additional terms
in the low energy effective theory of gravity, which amounts to a non-trivial
modification of the classical Einstein theory, fully consistent with the
Equivalence Principle. We show that the new dynamical degrees of freedom the
anomaly contains provide a natural mechanism for relaxing Lambda to zero on
cosmological scales. We consider possible signatures of the restoration of
conformal invariance predicted by the fluctuations of these new scalar degrees
of freedom on the spectrum and statistics of the CMB, in light of the latest
bounds from WMAP. Finally we assess the prospects for a new cosmological model
in which the dark energy adjusts itself dynamically to the cosmological horizon
boundary, and therefore remains naturally of order H^2 at all times without
fine tuning.Comment: 50 pages, Invited Contribution to New Journal of Physics Focus Issue
on Dark Energ
РОЛЬ НАУКОВО-ДОСЛІДНОЇ РОБОТИ В ПРАКТИЧНОМУ НАВЧАННІ СТУДЕНТІВ
The article adduces the methods of scientific research of medical school students. The students get the previous specialization of professional preparation carrying the research work out.У статті обгрунтовано важливість та подано методи проведення науково-дослідної роботи студентів медичного училища. Проводячи пошуково-дослідну роботу, студенти отримують попередню соціалізацію фахової підготовки, активно готуються до майбутньої професійної діяльності
Aharonov-Bohm interference in quantum ring exciton: effects of built-in electric fields
We report a comprehensive discussion of quantum interference effects due to
the finite structure of excitons in quantum rings and their first experimental
corroboration observed in the optical recombinations. Anomalous features that
appear in the experiments are analyzed according to theoretical models that
describe the modulation of the interference pattern by temperature and built-in
electric fields.Comment: 6 pages, 7 figure
ОСОБЛИВОСТІ ПІДГОТОВКИ МОЛОДШИХ МЕДИЧНИХ СПЕЦІАЛІСТІВ З ПРЕДМЕТА «МЕДИЦИНА КАТАСТРОФ» ЗА ФАХОМ «СЕСТРИНСЬКА СПРАВА»
The article adduces the necessity and expedience of studying the discipline «Medicine of catastrophes» on the prediploma stage of gunior medical and specialist's training the experience of teaching of this discipline at the nursing department of Kremenets Medical School by Arsen Richynskyi.У статті обгрунтовано необхідність та доцільність вивчення дисципліни «Медицина катастроф» на IV курсі підготовки молодшого медичного персоналу та наведено досвід викладання цієї дисципліни на сестринському відділенні Кременецького медичного училища імені Арсена Річинського
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