8,434 research outputs found
Two photon annihilation operators and squeezed vacuum
Inverses of the harmonic oscillator creation and annihilation operators by their actions on the number states are introduced. Three of the two photon annihilation operators, viz., a(sup +/-1)a, aa(sup +/-1), and a(sup 2), have normalizable right eigenstates with nonvanishing eigenvalues. The eigenvalue equation of these operators are discussed and their normalized eigenstates are obtained. The Fock state representation in each case separates into two sets of states, one involving only the even number states while the other involving only the odd number states. It is shown that the even set of eigenstates of the operator a(sup +/-1)a is the customary squeezed vacuum S(sigma) O greater than
Two-Proton Radioactivity with 2p halo in light mass nuclei A1834
Two-proton radioactivity with 2p halo is reported theoretically in light mass
nuclei A 18-34. We predict Mg, Si, S, Ar and
Ca as promising candidates of ground state 2p-radioactivity with
S 0. Observation of extended tail of spatial
charge density distribution, larger charge radius and study of proton single
particle states, Fermi energy and the wave functions indicate 2p halo like
structure which supports direct 2p emission. The Coulomb and centrifugal
barriers in experimentally identified 2p unbound Si show a quasi-bound
state that ensures enough life time for such experimental probes. Our
predictions are in good accord with experimental and other theoretical data
available so far.Comment: 5 Pages, 5 figure
Localized structures in Kagome lattices
We investigate the existence and stability of gap vortices and multi-pole gap
solitons in a Kagome lattice with a defocusing nonlinearity both in a discrete
case and in a continuum one with periodic external modulation. In particular,
predictions are made based on expansion around a simple and analytically
tractable anti-continuum (zero coupling) limit. These predictions are then
confirmed for a continuum model of an optically-induced Kagome lattice in a
photorefractive crystal obtained by a continuous transformation of a honeycomb
lattice
Chaetotaxy of three nymphal instars of an ischnoceran louse, Aegypoecus perspicuus (Phthiraptera: Insecta)
The present study on three nymphal instars of Aegypoecus perspicuus indicated that these differ from each other not only an size, abdominal segmentation, chitinization but also in the number of setae occurring on head, thorax and abdomen. The study also supplements informations regarding the morphological features and chaetotaxy of three nymphal instars of A. perspicuus, occurring on Neophron percnopterus. The diagnostic features of three nymphal instars have also been discussed
ROLE OF TERMINALIA ARJUNA IN ISCHEMIC HEART DISEASE (HRIDAROGA): A REVIEW
Now days, life is becoming very stressful and fast. As many diseases originate due to this hectic lifestyle. One of the important disease is Hridaroga (Ischemic heart disease), which is responsible for many deaths in early age. In Ayurveda, Hridaroga & their symptoms are described in many textbooks. Management of Hridaroga is also very critical and important. In modern medicine, only expensive interventional procedures are described but on the other hand, Ayurvedic herbs are better, cost effective & good therapeutic option for IHD (Hridaroga).
The review emphasizes on various properties of Terminalia arjuna. Many clinical & animal studies on T.arjuna show its effect on ECG changes, LV functions & myocardial ischaemic reperfusion injury-etc. Besides this it also has antiatherosclerotic, anticoagulant, anti-infarction, hypolipidemic & hypotensive properties. So, Ayurvedic drug (T. arjuna) is a better option for the treatment of IHD (Hridaroga) because it can improve the quality of life in individuals & potentially save millions of lives
Scaled free energies, power-law potentials, strain pseudospins and quasi-universality for first-order structural transitions
We consider ferroelastic first-order phase transitions with
order-parameter strains entering Landau free energies as invariant polynomials,
that have structural-variant Landau minima. The total free energy
includes (seemingly innocuous) harmonic terms, in the {\it
non}-order-parameter strains. Four 3D transitions are considered,
tetragonal/orthorhombic, cubic/tetragonal, cubic/trigonal and
cubic/orthorhombic unit-cell distortions, with respectively, and 2; and and 6. Five 2D transitions are also considered, as
simpler examples. Following Barsch and Krumhansl, we scale the free energy to
absorb most material-dependent elastic coefficients into an overall prefactor,
by scaling in an overall elastic energy density; a dimensionless temperature
variable; and the spontaneous-strain magnitude at transition .
To leading order in the scaled Landau minima become
material-independent, in a kind of 'quasi-universality'. The scaled minima in
-dimensional order-parameter space, fall at the centre and at the
corners, of a transition-specific polyhedron inscribed in a sphere, whose
radius is unity at transition. The `polyhedra' for the four 3D transitions are
respectively, a line, a triangle, a tetrahedron, and a hexagon. We minimize the
terms harmonic in the non-order-parameter strains, by substituting
solutions of the 'no dislocation' St Venant compatibility constraints, and
explicitly obtain powerlaw anisotropic, order-parameter interactions, for all
transitions. In a reduced discrete-variable description, the competing minima
of the Landau free energies induce unit-magnitude pseudospin vectors, with values, pointing to the polyhedra corners and the (zero-value) center.Comment: submitted to PR
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