608 research outputs found
Generators and relations for wreath products
Generators and defining relations for wreath products of groups are given.
Under some condition (conormality of the generators) they are minimal. In
particular, it is just the case for the Sylow subgroups of the symmetric
groups.Comment: 4 page
Representations of nodal algebras of type A
We define nodal finite dimensional algebras and describe their structure over
an algebraically closed field. For a special class of such algebras (type A) we
find a criterion of tameness.Comment: 19 pages
One branch curve singularities with at most 2-parameter families of ideals
A criterion is given in order that the ideals of a one branch curve
singularity form at most 2-parameter families. Namely, we present a list of
plane curve singularities from the Arnold's classification which are the
smallest among all one branch singularities having at most 2-parameter families
of ideals.Comment: 10 page
Influence of Zeeman splitting and thermally excited polaron states on magneto-electrical and magneto-thermal properties of magnetoresistive polycrystalline manganite La_{0.8}Sr_{0.2}MnO_3
Some possible connection between spin and charge degrees of freedom in
magneto-resistive manganites is investigated through a thorough experimental
study of the magnetic (AC susceptibility and DC magnetization) and transport
(resistivity and thermal conductivity) properties. Measurements are reported in
the case of well characterized polycrystalline La_{0.8}Sr_{0.2}MnO_3 samples.
The experimental results suggest rather strong field-induced polarization
effects in our material, clearly indicating the presence of ordered FM regions
inside the semiconducting phase. Using an analytical expression which fits the
spontaneous DC magnetization, the temperature and magnetic field dependences of
both electrical resistivity and thermal conductivity data are found to be well
reproduced through a universal scenario based on two mechanisms: (i) a
magnetization dependent spin polaron hopping influenced by a Zeeman splitting
effect, and (ii) properly defined thermally excited polaron states which have
to be taken into account in order to correctly describe the behavior of the
less conducting region. Using the experimentally found values of the magnetic
and electron localization temperatures, we obtain L=0.5nm and m_p=3.2m_e for
estimates of the localization length (size of the spin polaron) and effective
polaron mass, respectively.Comment: Accepted for publication in Journal of Applied Physic
WASA-FRS EXPERIMENTS IN FAIR PHASE-0 AT GSI
We have developed a new and unique experimental setup integrating the central part of the Wide Angle Shower Apparatus (WASA) into the Fragment Separator (FRS) at GSI. This combination opens up possibilities of new experiments with high-resolution spectroscopy at forward 0◦ and measurements of light decay particles with nearly full solid-angle acceptance in coincidence. The first series of the WASA-FRS experiments have been successfully carried out in 2022. The developed experimental setup and two physics experiments performed in 2022 including the status of the preliminary data analysis are introduced.</p
Accurate simultaneous lead stopping power and charge-state measurements in gases and solids:Benchmark data for basic atomic theory and nuclear applications
We have measured for the first time simultaneously both the mean charge states and stopping powers of (35–280) MeV/u 208Pb ions in gases and solids with an accuracy of 1%. The existence at lower energies and disappearance at higher of density effects in the charge-state distribution and the corresponding stopping power are directly confirmed and comparisons with widely used theories and simulations for heavy ions demonstrate strong deviations of up to 27%. However, an unprecedented prediction power of better than 3% has been achieved for the energy loss when the measured mean charge-states are implemented in the Lindhard-Sørensen theory. Our present benchmark data contribute to an improved understanding of the basic atomic collision processes and to numerous applications in nuclear physics. Extending the GANIL data [1] to higher accuracy and energies, we can now answer at which velocities the Bohr-Lindhard density effect in stopping will vanish.</p
Spectroscopy of η<sup>0</sup>-mesic nuclei with WASA at GSI/FAIR
We plan to conduct an experimental search for η0-mesic nuclei in order to investigate in-medium properties of the η0 meson. A 2.5 GeV proton beam is employed to produce η0-mesic 11C nuclei with the 12C(p,d)η0⊗ 11C reaction. Simultaneous measurements of the forward ejected deuterons and decay protons from η0-mesic nuclei will allow us to achieve high experimental sensitivity. The experiment will be performed at GSI by making full use of the fragment separator FRS and the WASA detector system. The plan of this proposed experiment is described.</p
Magnetostimulated inhomogeneity of electric field in aluminum
The results of low temperature experimental and theoretical study of potential distribution of stationary electric field in Al under the action of inhomogeneous magnetic field are presented
СУЧАСНИЙ СТАН ТА СТРАТЕГІЧНІ ОРІЄНТИРИ РОЗВИТКУ БАНКІВСЬКОГО СЕКТОРУ ЕКОНОМІКИ УКРАЇНИ В УМОВАХ КРИЗИ
The article is devoted to defining strategic guidelines of the banking sector of Ukraine's economy through the determination of its problems, which are becoming a significant impact on today’s crisis stage of economic development of the country. In addition it analyzes the main indicators of banks' activity in Ukraine and trends in the banking sector of the economy. In order to determine the prospects of banking sector development, author gives the SWOT-analysis with the purpose to identify its (Ukrainian banking sector) internal strengths and weaknesses, as well as its external opportunities and threats. Given the problems in the banking sector of Ukraine and the SWOT-analysis results, author also recommended some ways to improve the banking in Ukraine.Статья посвящена определению стратегических ориентиров развития банковского сектора экономики Украины через обозначение его проблем, которые приобретают значительного влияния на современном - кризисном - этапе экономического развития страны. Проанализированы основные показатели деятельности банков в Украине и тенденции функционирования банковского сектора экономики.Стаття присвячена визначенню стратегічних орієнтирів розвитку банківського сектору економіки України через окреслення його проблем, які набувають значного впливу на сучасному – кризовому – етапі економічного розвитку держави. Проаналізовано основні показники діяльності банків в Україні та тенденції функціонування банківського сектору економік
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