1,132 research outputs found
Optimal cloning for finite distributions of coherent states
We derive optimal cloning limits for finite Gaussian distributions of
coherent states, and describe techniques for achieving them. We discuss the
relation of these limits to state estimation and the no-cloning limit in
teleportation. A qualitatively different cloning limit is derived for a
single-quadrature Gaussian quantum cloner.Comment: 15 pages RevTeX, 6 figures eps, submitted to PR
Post-secondary-school migration of young people to large regional centres as a factor of depopulation and disharmonious regional development in Poland
Purpose: The purpose of this article is to demonstrate that the youth internal migrations are not, as is generally accepted, temporary, in order to obtain an education, but permanent in the final intention. Design/Methodology/Approach: The survey were carried in two different regions: one with a strong (large) regional center and the other with the weaker (smaller) center. In those region secondary education centers of various sizes were selected. There were conducted an auditorium survey among 2380 young people graduating from general secondary schools. The basis of the study was a survey containing several questions and determining five features related to background legal data. Findings: Education migrations "to study" become the beginning of the final emigration addressed to the metropolitan city as a large academic center. The research results also proved that the process of draining small regions centers by large regional centers leads to a deepening of differences in the development of regions, especially their capitals. Practical Implications: The results of analysis might be used in shaping an appropriate development policy. They may also indicate the need for more than proportional support for small regional capitals or - looking from a different perspective - to real processes of the territorial division of the country. Originality/Value: Research results can contribute to the construction of theoretical models regarding migration and local and regional developmentpeer-reviewe
On scattering cross sections and durations near an isolated compound-resonance, distorted by the non-resonant background, in the center-of-mass and laboratory systems
During last 20 years there was revealed and published the phenomenon of the
appearing of the time advance instead of the time delay at the region of a
compound-nucleus resonance, distorted by the non-resonant background (in the
center-of-mass (C-) system). This phenomenon is usually accompanied by a
minimum in the cross section near the same energy. Here we analyze the cross
section and the time delay of the nucleon-nucleus scattering in the laboratory
(L-) system. In the L-system the delay-advance phenomenon does not appear. We
use and concretize the non-standard analytical transformations of the cross
section from the C-system to the L-system, obtained in our previous papers.
They are illustrated by the calculations of energy dependences of cross
sections in the L-system for several cases of nucleon elastic scattering by
nuclei 12C, 16O, 28Si, 52Cr, 56Fe and 64Ni at the range of distorted resonances
in comparison with the experimental data.Comment: 11 pages, 7 figure
Influence of second oder aberrations on mass-separation with 270° analyzing magnet
In this paper we study nonlinear characteristics of the wide aperture dipole magnet CP-17, which is utilized as an analyzing magnet in the stable isotope separator of the INR (Institute for Nuclear Research) in Kiev. A brief theory of the second order aberration of the magnetic field is outlined. Based on this theory numerical calculations have been performed to study the achievable power resolution depending on nonlinear magnetic field and on beam parameters.Досліджуються характеристики широко-апертурного магніту СП-17, який планується використовувати як аналізуючий магніт мас-сепаратора ІЯД (Інститут ядерних досліджень) у Києві. Наведена коротка теорія аберацій другого порядку. На основі описаної теорії проведено цілий ряд чисельних розрахунків для дослідження розподільної здатності сепаратора в залежності від нелінійності магнітного поля, а також від параметрів пучка.Исследуются характеристики широко-апертурного дипольного магнита СП-17, который планируется использовать в качестве анализирующего магнита масс-сепаратора ИЯИ (Институт ядерных исследований) в Киеве. Приведена краткая теория аберраций второго порядка. На основе описанной теории проведена серия численных расчетов для исследования разрешающей способности сепаратора в зависимости от нелинейности магнитного поля, а также от параметров пучка
Optical squeezing in temporal, polarization, and spatial domains
We present methods of transforming the standard quadrature amplitude squeezing of a continuous-wave light beam to its Stokes parameters and transverse spatial modes statistics. These two states of light are called polarization squeezing and spatial squeezing, respectively. We present experimental results of the quadrature amplitude, polarization and spatial squeezing obtained with a common experimental setup based on optical parametric amplifiers. The transformations from quadrature amplitude to polarization and spatial squeezing are achieved with only simple linear optics
βB1-Crystallin: Thermodynamic Profiles of Molecular Interactions
β-Crystallins are structural proteins maintaining eye lens transparency and opacification. Previous work demonstrated that dimerization of both βA3 and βB2 crystallins (βA3 and βB2) involves endothermic enthalpy of association (∼8 kcal/mol) mediated by hydrophobic interactions.Thermodynamic profiles of the associations of dimeric βA3 and βB1 and tetrameric βB1/βA3 were measured using sedimentation equilibrium. The homo- and heteromolecular associations of βB1 crystallin are dominated by exothermic enthalpy (-13.3 and -24.5 kcal/mol, respectively).Global thermodynamics of βB1 interactions suggest a role in the formation of stable protein complexes in the lens via specific van der Waals contacts, hydrogen bonds and salt bridges whereas those β-crystallins which associate by predominately hydrophobic forces participate in a weaker protein associations
Measurement of the cross-section ratio sigma_{psi(2S)}/sigma_{J/psi(1S)} in deep inelastic exclusive ep scattering at HERA
The exclusive deep inelastic electroproduction of and
at an centre-of-mass energy of 317 GeV has been studied with the ZEUS
detector at HERA in the kinematic range GeV,
GeV and GeV, where is the photon virtuality, is the
photon-proton centre-of-mass energy and is the squared four-momentum
transfer at the proton vertex. The data for GeV were taken in
the HERA I running period and correspond to an integrated luminosity of 114
pb. The data for GeV are from both HERA I and HERA II
periods and correspond to an integrated luminosity of 468 pb. The decay
modes analysed were and for the
and for the . The cross-section ratio
has been measured as a function of
and . The results are compared to predictions of QCD-inspired
models of exclusive vector-meson production.Comment: 24 pages, 8 figure
Measurement of neutral current e+/-p cross sections at high Bjorken x with the ZEUS detector
The neutral current e+/-p cross section has been measured up to values of
Bjorken x of approximately 1 with the ZEUS detector at HERA using an integrated
luminosity of 187 inv. pb of e-p and 142 inv. pb of e+p collisions at sqrt(s) =
318GeV. Differential cross sections in x and Q2, the exchanged boson
virtuality, are presented for Q2 geq 725GeV2. An improved reconstruction method
and greatly increased amount of data allows a finer binning in the high-x
region of the neutral current cross section and leads to a measurement with
much improved precision compared to a similar earlier analysis. The
measurements are compared to Standard Model expectations based on a variety of
recent parton distribution functions.Comment: 39 pages, 9 figure
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