66 research outputs found
Hard loss of stability in Painlev\'e-2 equation
A special asymptotic solution of the Painlev\'e-2 equation with small
parameter is studied. This solution has a critical point corresponding to
a bifurcation phenomenon. When the constructed solution varies slowly
and when the solution oscillates very fast. We investigate the
transitional layer in detail and obtain a smooth asymptotic solution, using a
sequence of scaling and matching procedures
Weakly-nonlocal Symplectic Structures, Whitham method, and weakly-nonlocal Symplectic Structures of Hydrodynamic Type
We consider the special type of the field-theoretical Symplectic structures
called weakly nonlocal. The structures of this type are in particular very
common for the integrable systems like KdV or NLS. We introduce here the
special class of the weakly nonlocal Symplectic structures which we call the
weakly nonlocal Symplectic structures of Hydrodynamic Type. We investigate then
the connection of such structures with the Whitham averaging method and propose
the procedure of "averaging" of the weakly nonlocal Symplectic structures. The
averaging procedure gives the weakly nonlocal Symplectic Structure of
Hydrodynamic Type for the corresponding Whitham system. The procedure gives
also the "action variables" corresponding to the wave numbers of -phase
solutions of initial system which give the additional conservation laws for the
Whitham system.Comment: 64 pages, Late
Synthesis and Thermal Stability of Cubic ZnO in the Salt Nanocomposites
Cubic zinc oxide (rs-ZnO), metastable under normal conditions, was
synthesized from the wurtzite modification (w-ZnO) at 7.7 GPa and ~800 K in the
form of nanoparticles isolated in the NaCl matrix. The phase transition rs-ZnO
\rightarrow w-ZnO in nanocrystalline zinc oxide under ambient pressure was
experimentally studied for the first time by differential scanning calorimetry
and high-temperature X-ray diffraction. It was shown that the transition occurs
in the 370-430 K temperature range and its enthalpy at 400 K is -10.2 \pm 0.5
kJ mol-1.Comment: 12 pages, 4 figures, 1 tabl
Double Beta Decay: Historical Review of 75 Years of Research
Main achievements during 75 years of research on double beta decay have been
reviewed. The existing experimental data have been presented and the
capabilities of the next-generation detectors have been demonstrated.Comment: 25 pages, typos adde
Has charge symmetry breaking been observed in the d d -> alpha pi0 reaction?
Estimates are made of the d d -> alpha gamma gamma production cross sections
in a model where each neutron-proton pair in the beam and target initiates an n
p -> d gamma reaction. This approach, which successfully reproduces observables
in two-pion production at intermediate energies, suggests that direct
two-photon production could provide a very significant background to the
measurement of the charge-symmetry-breaking (CSB) reaction d d -> alpha pi0. A
non-vanishing CSB cross section has been reported which might be confused with
such two-photon production under the given experimental conditions.Comment: 9 pages, ReVTEX, 2 figures, submitted to Phys. Rev. Let
- …