1,300 research outputs found
On circulant states with positive partial transpose
We construct a large class of quantum "d x d" states which are positive under
partial transposition (so called PPT states). The construction is based on
certain direct sum decomposition of the total Hilbert space displaying
characteristic circular structure - that is way we call them circulant states.
It turns out that partial transposition maps any such decomposition into
another one and hence both original density matrix and its partially transposed
partner share similar cyclic properties. This class contains many well known
examples of PPT states from the literature and gives rise to a huge family of
completely new states.Comment: 15 pages; minor correction
The cellular composition of the adrenal medulla of sexually mature guinea pigs
The adrenal glands from 15 guinea pigs aged 90 days were used in the study.
Paraffin slices were stained with Mayer haematoxylin and eosin with Masson
method and silvered. The histochemical reactions were carried out for catecholamines
and the biochemical determinations of catecholamines. Ultrastructural
observations were also performed.
In the adrenal medulla of sexually mature guinea pigs numerous epinephrocites
and no noreoinefrocites were observed when histochemical methods were used.
The small and large ganglion cells accompanying the supporting and neurolemmal
cells formed typical gangliar weaving (medullary ganglia). Apart from epinephrocytes,
small and large ganglion cells and supporting and neurolemmal
cells, small intensively fluorescent (SIF) cells were also detected.
Biochemical investigation revealed that the mean content of adrenaline calculated
for a pair of adrenal glands was 98.87% of the pool of catecholamines,
whereas the mean content of noradrenaline was 1.00%, and of dopamine 0.13%
Next-to-leading term of the renormalized stress-energy tensor of the quantized massive scalar field in Schwarzschild spacetime. The back reaction
The next-to-leading term of the renormalized stress-energy tensor of the
quantized massive field with an arbitrary curvature coupling in the spacetime
of the Schwarzschild black hole is constructed. It is achieved by functional
differentiation of the DeWitt-Schwinger effective action involving coincidence
limit of the Hadamard-Minakshisundaram-DeWitt-Seely coefficients and
The back reaction of the quantized field upon the Schwarzschild black
hole is briefly discussed
Kinetics and mechanism of the reaction of acetonyl radical, CH3(CO)CH2, with Br2
The low pressure fast discharge flow method with laser induced fluorescence detection of CH3C(O)CH2 was employed to study the kinetics of the reaction CH3C(O)CH2 + Br2 → CH3C(O)CH2Br + Br (1) at 298, 323 and 365 K. The rate coefficient at room temperature is k1 = (2.33 ± 0.04 (2σ)) 10–12 cm3 molecule–1 s–1, which increases slightly with increasing temperature. Quantum chemistry (G2) and theoretical rate theory (conventional TST) computations have supplied results in qualitative agreement with experiment. The relatively slow rate of reaction (1) can be due to the resonance stabilization of the acetonyl radical.
Keywords: reaction kinetics, acetonyl radical, Br2 molecule, resonance stabilizatio
Quantum Mechanics of Damped Systems II. Damping and Parabolic Potential Barrier
We investigate the resonant states for the parabolic potential barrier known
also as inverted or reversed oscillator. They correspond to the poles of
meromorphic continuation of the resolvent operator to the complex energy plane.
As a byproduct we establish an interesting relation between parabolic cylinder
functions (representing energy eigenfunctions of our system) and a class of
Gel'fand distributions used in our recent paper.Comment: 14 page
Trailing and smooth-seeded wild beans: native annual warm season legumes for Texas
Last updated: 10/22/201
Magnetospheric Multiscale Observations of Markov Turbulence on Kinetic Scales
In our previous studies we have examined solar wind and magnetospheric
plasmas turbulence, including Markovian character on large inertial
magneto-hydrodynamic scales. Here we present the results of statistical
analysis of magnetic field fluctuations in the Earth's magnetosheath based on
Magnetospheric Multiscale mission at much smaller kinetic scales. Following our
results on spectral analysis with very large slopes of about -16/3, we apply
Markov processes approach to turbulence in this kinetic regime. It is shown
that the Chapman-Kolmogorov equation is satisfied and the lowest-order
Kramers-Moyal coefficients describing drift and diffusion with a power-law
dependence are consistent with a generalized Ornstein-Uhlenbeck process. The
solutions of the Fokker-Planck equation agree with experimental probability
density functions, which exhibit a universal global scale invariance through
the kinetic domain. In particular, for moderate scales we have the kappa
distribution described by various peaked shapes with heavy tails, which with
large values of kappa parameter are reduced to the Gaussian distribution for
large inertial scales. This shows that the turbulence cascade can be described
by the Markov processes also on very small scales. The obtained results on
kinetic scales may be useful for better understanding of the physical
mechanisms governing turbulenceComment: accepted to Astrophys. J. 2 November 2022, 17 pages, 7 figure
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