1,300 research outputs found

    On circulant states with positive partial transpose

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    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

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    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

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    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 a3a_{3} and a4.a_{4}. 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

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    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

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    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

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    Last updated: 10/22/201

    Magnetospheric Multiscale Observations of Markov Turbulence on Kinetic Scales

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    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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