173 research outputs found
Isospin dependence of mass-distribution shape of fission fragments of Hg isotopes
Using an improved scission-point model, the mass distributions are calculated for induced fission of even Hg isotopes with mass numbers A=174 to 196. With increasing A of a fissioning AHg nucleus the mass distribution evolves from symmetric for 174Hg, to asymmetric for isotopes close to 180Hg, and back to more symmetric for 192,194,196Hg. In the fissioning Hg isotopes their excitation energy weakly influences the shape of the mass distribution. In 180,184Hg, the mass distributions of fission fragments remain asymmetric even at high excitation energies
Conductance of non-ballistic point contacts in hybrid systems "normal metal/superconductor" Cu/Mo-C and Cu/LaOFFeAs
We consider the shape of the curves of "Andreev" conductance of non-ballistic
point contact NS heterosystems depending on the bias voltage at the contact.
The obtained shape of those curves is caused by the contribution from the
mechanism of coherent scattering by impurities which doubles the scattering
cross section. The behavior of generalized and differential conductance is
compared for ballistic and non-ballistic transport regimes. The criteria are
considered allowing one to discriminate between those regimes with the
corresponding conduction curves similar in appearance. The analysis is extended
to the case of non-ballistic transport in NS point contacts with exotic
superconductors, molybdenum carbide Mo-C and oxypnictide
La[OF]FeAs from a group of iron-based superconductors
Polarization SAR system
Основная статьяA mathematical model is constructed for the dependence of the
specific ESR on the slip angle for various types of X-band surfaces. A fully
polarimetric radar image of a terrain site, synthesized from a three-dimensional
model of the underlying surface
Evaluation of the low-lying energy levels of two- and three-electron configurations for multi-charged ions
Accurate QED evaluations of the one- and two-photon interelectron interaction
for low lying two- and three-electron configurations for ions with nuclear
charge numbers are performed. The three-photon interaction is
also partly taken into account. The Coulomb gauge is employed. The results are
compared with available experimental data and with different calculations. A
detailed investigation of the behaviour of the energy levels of the
configurations , near
the crossing points Z=64 and Z=92 is carried out. The crossing points are
important for the future experimental search for parity nonconserving (PNC)
effects in highly charged ions
Evaluation of the two-photon exchange diagrams for the electron configuration in Li-like ions
We present ab initio calculations of the complete gauge-invariant set of
two-photon exchange graphs for the electron configuration in
Li-like ions. These calculations are an important step towards the precise
theoretical determination of the - transition energy in the
framework of QED.Comment: 17 pages, 6 figure
Full Counting Statistics of Charge Transfer in Coulomb Blockade Systems
Full counting statistics (FCS) of charge transfer in mesoscopic systems has
recently become a subject of significant interest, since it proves to reveal an
important information about the system which can be hardly assessed by other
means. While the previous research mostly addressed the FCS of non- interacting
systems, the present paper deals with the FCS in the limit of strong
interaction. In this Coulomb blockade limit the electron dynamics is known to
be governed by a master equation. We develop a general scheme to evaluate the
FCS in such case, this being the main result of the work presented. We
illustrate the scheme, by applying it to concrete systems. For generic case of
a single resonant level we establish the equivalence of scattering and master
equation approach to FCS. Further we study a single Coulomb blockade island
with two and three leads attached and compare the FCS in this case with our
recent results concerning an open dot either with two and three terminals. We
demonstrate that Coulomb interaction suppresses the relative probabilities of
large current fluctuations.Comment: 17 pages, 16 figure
Formation of MoO₃ crystals in electric arc plasma source
Formation of molybdenum trioxide crystals by electric arc discharge between molybdenum electrodes is considered. Molybdenum oxide crystals were deposited on side surface of anode. Observation of crystals formation zone was used for determination of main formations stages. Plasma temperature was estimated by optical emission spectroscopy method. The resulting products were studied by X-rays diffraction, time-of-flight laser mass-spectrometry and optical microscopy methods. It was found, that self-organizing vapor-deposition process of MoO₃ crystals formation has place. The resulting product is colorless sparkling prisms and platelets, which are mainly consist of orthorhombic α-MoO₃ phase. Optical microscopy indicates the formation of closely packed feather-like pin structures by vapor-solid process.Рассматривается формирование кристаллов триоксида молибдена при помощи электродугового разряда между молибденовыми электродами. Кристаллы формировались на боковой поверхности анода во время горения дуги. Эти кристаллы представляют собой прозрачные блестящие призмы и пластинки, состоящие, главным образом, из орторомбической фазы MoO₃. Для определения основных этапов формирования кристаллов, их химического состава и структуры применялись наблюдение зоны роста, рентгеноструктурный анализ, времяпролетная масс-спектрометрия и микроскопические исследования.Розглянуто формування кристалів триоксиду молібдену за допомогою електродугового розряду між молібденовими електродами. Кристали формувались на боковій поверхні анода під час горіння вільноіснуючої електричної дуги. Ці кристали являли собою прозорі блискучі призми та пластинки, які складались, головним чином, із орторомбічної фази MoO₃. Для визначення основних етапів формування кристалів, їх хімічного складу та структури застосовувались спостереження зони росту
QED Effects in Heavy Few-Electron Ions
Accurate calculations of the binding energies, the hyperfine splitting, the
bound-electron g-factor, and the parity nonconservation effects in heavy
few-electron ions are considered. The calculations include the relativistic,
quantum electrodynamic (QED), electron-correlation, and nuclear effects. The
theoretical results are compared with available experimental data. A special
attention is focused on tests of QED in a strong Coulomb field.Comment: 28 pages, 6 tables, 5 figure
Quasiclassical Theory of Spontaneous Currents at Surfaces and Interfaces of d-Wave Superconductors
We investigate the properties of spontaneous currents generated at surfaces
and interfaces of d-wave superconductors using the self-consistent
quasiclassical Eilenberger equations. The influence of the roughness and
reflectivity of the boundaries on the spontaneous current are studied. We show
that these have very different effects at the surfaces compared to the
interfaces, which reflects the different nature of the time reversal symmetry
breaking states in these two systems. We find a signature of the ``anomalous
proximity effect'' at rough d-wave interfaces. We also show that the existence
of a subdominant order parameter, which is necessary for time reversal symmetry
breaking at the surface, suppresses the spontaneous current generation due to
proximity effect at the interface between two superconductors. We associate
orbital moments to the spontaneous currents to explain the ``superscreening''
effect, which seems to be present at all ideal d-wave surfaces and interfaces,
where d_{xy} is the favorite subdominant symmetry.Comment: 13 pages, 17 postscript figure
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