164 research outputs found
A comparative study of super- and highly-deformed bands in the A ~ 60 mass region
Super- and highly-deformed rotational bands in the A ~ 60 mass region are
studied within cranked relativistic mean field theory and the
configuration-dependent shell-correction approach based on the cranked Nilsson
potential. Both approaches describe the experimental data well. Low values of
the dynamic moments of inertia J^(2) compared with the kinematic moments of
inertia J^(1) seen both in experiment and in calculations at high rotational
frequencies indicate the high energy cost to build the states at high spin and
reflect the limited angular momentum content in these configurations.Comment: 11 pages, 4 PostScript figures, Latex, uses 'epsf', submitted to
Phys. Lett.
Time-odd mean fields in the rotating frame: microscopic nature of nuclear magnetism
The microscopic role of nuclear magnetism in rotating frame is investigated
for the first time in the framework of the cranked relativistic mean field
theory. It is shown that nuclear magnetism modifies the expectation values of
single-particle spin, orbital and total angular momenta along the rotational
axis effectively creating additional angular momentum. This effect leads to the
increase of kinematic and dynamic moments of inertia at given rotational
frequency and has an impact on effective alignments.Comment: 16 pages, 4 figures, submitted to Physical Review
Recent progress in the study of fission barriers in covariant density functional theory
Recent progress in the study of fission barriers of actinides and superheavy
nuclei within covariant density functional theory is overviewed.Comment: 10 pages, 5 figures. In press in International Journal of Modern
Physics
УГОИТЕЛНИ СПОСОБНОСТИ И КАЧЕСТВО НА МЕСОТО ПРИ ЯПОНСКИ ПЪДПЪДЪЦИ ОТ ПОРОДИТЕ “ФАРАОН” И “БЕЛИ АНГЛИЙСКИ”
The aim of the study was to establish the fatting capacity and the meat quality of the combined (meat+eggs) White English breed and to compare with the same of the meat Faraon breed. Logically, the live weight of 31-day old male Faraon-birds was by 5,9 % higher and of the female ones – by 7,9 % compared to the birds of White English
breed. Feed conversion ratio for the experimental period (3-31 days) for the White English quails was to 9,95% less effective, compared to the Faraon birds. The meat of Faraon quails contained more dry matter and protein compared to the meat of White English breed. Fat content in the quail bodies of White English breed was signifi cantly lower compared to Faraon breed /Р≤0,05/. Quail meat of White English breed was characterized by its better capacity for
technological processing due to the lower loss of moisture – by 18,8 % for breast and 22,4 % for leg muscles /Р≤0,05/. The established results characterize the combined White English breed as suitable for producing both of eggs and meat from quails.Целта на изследването е да се проучат угоителните способности и качеството на месото на месо-яйчната порода Бели английски, като се сравни с това на използваната в целия свят специализирана месодайна порода Фараон. Логично на 31-дневна възраст живата маса на мъжките птици от породата Фараон е била с 5,9% по- висока, а при женските - със 7,9% в сравнение с птиците от породата Бели английски. Средно за опитния период (3-31 дни), конверсията на фураж при птиците от породата Бели английски е била с 9,95% по-неефективна в
сравнение с тази при месодайната порода Фараон. Месото на птиците от породата Фараон е по-богато на сухи вещества и протеин - съответно с 8% при гръдната и 8,5% при крачната мускулатура сухи вещества и с 3,2% при гръдната и 4,6% при крачната мускулатура протеин. Съдържанието на мазнини в трупчета от породата Бели английски е достоверно по-ниско в сравнение с трупчетата на породата Фараон /Р≤0,05/. Месото на пъдпъдъците от породата Бели английски се характеризира с по-добра пригодност за технологична преработка, поради по-ниската загуба на влага – с 18,8% за гръдната и с 22,4% за крачната мускулатура / Р≤0,05/. Получените резултати характеризират породата Бели английски като подходяща за производство на яйца и месо от японски пъдпъдъци
Moments of Inertia of Nuclei in the Rare Earth Region: A Relativistic versus Non-Relativistic Investigation
A parameter free investigation of the moments of inertia of ground state
rotational bands in well deformed rare-earth nuclei is carried out using
Cranked Relativistic Hartree-Bogoliubov (CRHB) and non-relativistic Cranked
Hartree-Fock-Bogoliubov (CHFB) theories. In CRHB theory, the relativistic
fields are determined by the non-linear Lagrangian with the NL1 force and the
pairing interaction by the central part of finite range Gogny D1S force. In
CHFB theory, the properties in particle-hole and particle-particle channels are
defined solely by Gogny D1S forces. Using an approximate particle number
projection before variation by means of the Lipkin Nogami method improves the
agreement with the experimental data, especially in CRHB theory. The effect of
the particle number projection on the moments of inertia and pairing energies
is larger in relativistic than in non-relativistic theory.Comment: 18 pages + 2 PostScript figure
Large collection of astrophysical S-factors and its compact representation
Numerous nuclear reactions in the crust of accreting neutron stars are
strongly affected by dense plasma environment. Simulations of superbursts, deep
crustal heating and other nuclear burning phenomena in neutron stars require
astrophysical S-factors for these reactions (as a function of center-of-mass
energy E of colliding nuclei). A large database of S-factors is created for
about 5000 non-resonant fusion reactions involving stable and unstable isotopes
of Be, B, C, N, O, F, Ne, Na, Mg, and Si. It extends the previous database of
about 1000 reactions involving isotopes of C, O, Ne, and Mg. The calculations
are performed using the Sao Paulo potential and the barrier penetration
formalism. All calculated S-data are parameterized by an analytic model for
S(E) proposed before [Phys. Rev. C 82, 044609 (2010)] and further elaborated
here. For a given reaction, the present S(E)-model contains three parameters.
These parameters are easily interpolated along reactions involving isotopes of
the same elements with only seven input parameters, giving an ultracompact,
accurate, simple, and uniform database. The S(E) approximation can also be used
to estimate theoretical uncertainties of S(E) and nuclear reaction rates in
dense matter, as illustrated for the case of the 34Ne+34Ne reaction in the
inner crust of an accreting neutron star.Comment: 13 pages, 2 figures, Phys. Rev. C, accepte
Cranked Relativistic Hartree-Bogoliubov Theory: Superdeformed Bands in the Region
Cranked Relativistic Hartree-Bogoliubov (CRHB) theory is presented as an
extension of Relativistic Mean Field theory with pairing correlations to the
rotating frame. Pairing correlations are taken into account by a finite range
two-body force of Gogny type and approximate particle number projection is
performed by Lipkin-Nogami method. This theory is applied to the description of
yrast superdeformed rotational bands observed in even-even nuclei of the mass region. Using the well established parameter sets NL1 for the
Lagrangian and D1S for the pairing force one obtains a very successful
description of data such as kinematic () and dynamic ()
moments of inertia without any adjustment of new parameters. Within the present
experimental accuracy the calculated transition quadrupole moments agree
reasonably well with the observed data.Comment: 6 pages including 4 PostScript figures, uses RevTex, revised version,
Phys.Rev. C, Rapid Communications, in pres
A New Parameterization for the Lagrangian Density of Relativistic Mean Field Theory
A new parameterization for an effective non-linear Lagrangian density of
relativistic mean field (RMF) theory is proposed, which is able to provide an
excellent description not only for the properties of stable nuclei but also for
those far from the valley of beta-stability. In addition recently measured
superdeformed mimima in the Hg-region are reproduced with high accuracy.Comment: 8 pages, Latex, 1 ps figur
A Uniform Analysis of the Ly-alpha forest at z = 0 - 5: I. The sample and distribution of clouds at z > 1.7
We present moderate resolution data for 39 QSOs at z 2 obtained at
the Multiple Mirror Telescope. These data are combined with spectra of
comparable resolution of 60 QSOs with redshifts greater than 1.7 found in the
literature to investigate the distribution of Ly-alpha forest lines in redshift
and equivalent width. We find a value for , the parameter describing
the number distribution of Ly-alpha forest lines in redshift, of
for lines stronger than a rest equivalent width of 0.32 , in good
agreement with some previous studies. The Kolmogorov-Smirnov test was applied
to the data and it is found that this single power law is a good fit over the
relevant redshift ranges. Simulations of the Lyman alpha forest were performed
to determine the completeness of the line lists and to test how well the
analysis the underlying line statistics, given this level of completeness.Comment: minor corrections to text, 37 Latex pages, 11 encapsulated Postscript
figures, uses emulateapj.sty, To appear in the Sept. 2000 ApJS, line lists
and spectra available at http://qso.as.arizona.edu/~jscott/Spectra/index.htm
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