4,854 research outputs found

    Shifts of semi-invariants and complete commutative subalgebras in polynomial Poisson algebras

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    We study commutative subalgebras in the symmetric algebra S(g)S(\mathfrak{g}) of a finite-dimensional Lie algebra g\mathfrak{g}. A. M. Izosimov introduced extended Mischenko-Fomenko subalgebras F~a\tilde{\mathcal{F}}_a and gave a completeness criterion for them. We generalize his construction and extend Mischenko-Fomenko subalgebras with the shifts of all semi-invariants of g\mathfrak{g}. We prove that the new commutative subalgebras have the same transcendence degree as F~a\tilde{\mathcal{F}}_a

    Enhancement of the electric dipole moment of the electron in PbO

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    The a(1) state of PbO can be used to measure the electric dipole moment of the electron d_e. We discuss a semiempirical model for this state, which yields an estimate of the effective electric field on the valence electrons in PbO. Our final result is an upper limit on the measurable energy shift, which is significantly larger than was anticipated earlier: 2Wdde2.4×1025Hz[deecm] 2|W_d|d_e \ge 2.4\times 10^{25} \textrm{Hz} [ \frac{d_e}{e \textrm{cm}} ].Comment: 4 pages, revtex4, no figures, submitted to PR

    Dynamics of cadmium acclumulation in the internal organs of rats after exposure to cadmium chloride and cadmium sulphide nanopartiles of various sizes.

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    The article presents the results of study of cadmium accumulation in the internal organs of Wistar rats after prolonged intraperitoneal administration of cadmium chloride and cadmium sulphide nanoparticles of 4-6 nm and 9-11 nm in size in a dose of 0.08 mg /kg/day calculated as cadmium. Toxic effects were evaluated after 30 injections (1.5 months), 60 injections (3 months), and 1.5 months after the exposure has been ceased. The results of the study showed that the most intensive accumulation of cadmium was observed in the kidneys and liver of experimental animals, which is due to the peculiarities of the toxicokinetics and the route of administration of cadmium compounds. In the kidneys, spleen and thymus of animals exposed to cadmium sulphide nanoparticles, a greater concentration of cadmium than in the organs of animals exposed to cadmium chloride was found. Cadmium accumulated more intensively in the spleen after exposure to larger nanoparticles, than in the kidneys and thymus. In the liver, heart, aorta and brain significant accumulation was observed after cadmium chloride exposure.

    Electric dipole moment of the electron in YbF molecule

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    Ab initio calculation of the hyperfine, P-odd, and P,T-odd constants for the YbF molecule was performed with the help of the recently developed technique, which allows to take into account correlations and polarization in the outercore region. The ground state electronic wave function of the YbF molecule is found with the help of the Relativistic Effective Core Potential method followed by the restoration of molecular four-component spinors in the core region of ytterbium in the framework of a non-variational procedure. Core polarization effects are included with the help of the atomic Many Body Perturbation Theory for Yb atom. For the isotropic hyperfine constant A, accuracy of our calculation is about 3% as compared to the experimental datum. The dipole constant Ad (which is much smaller in magnitude), though better than in all previous calculations, is still underestimated by almost 23%. Being corrected within a semiempirical approach for a perturbation of 4f-shell in the core of Yb due to the bond making, this error is reduced to 8%. Our value for the effective electric field on the unpaired electron is 4.9 a.u.=2.5E+10 V/cm.Comment: 7 pages, REVTE

    Enhancement of the electric dipole moment of the electron in the YbF molecule

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    We calculate an effective electric field on the unpaired electron in the YbF molecule. This field determines sensitivity of the molecular experiment to the electric dipole moment of the electron. We use experimental value of the spin-doubling constant to estimate the admixture of the configuration with the hole in the 4f-shell of Ytterbium to the ground state of the molecule. This admixture reduces the field by 7%. Our value for the effictive field is 5.1 a.u. = 2.5 10^{10} V/cm.Comment: 5 pages, LATEX, uses revtex.st
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