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151.
152.
T. Lönnroth P. Ahonen R. Julin S. Juutinen A. Lampinen A. Pakkanen S. Törmänen W. Trzaska A. Virtanen 《Zeitschrift für Physik A Hadrons and Nuclei》1990,337(1):11-14
The isomeric decay of theT 1/2=94 us isomeric state in201Hg was studied in beam via the reaction198Pt(α, n). Gamma-ray and conversion-electron spectra were recorded. From the conversion coefficients, the multipolarities of the two depopulating transitions were determined to beM 2 + 10%E 3 andE 2, respectively. These assignments give the depopulating transitions to be 13/2+ → 9/2? and 9/2? → 5/2?, and these thus substantiate the previous suggestion that the isomeric state hasJ π=13/2+. For the 13/2+ → 9/2? M 2 transition a detailed study ofE 3 andM 4 admixed amplitudes was done. The microscopic properties of the 13/2+ and 9/2? states are discussed, and a comparison to the corresponding ones in199,203,205Hg is made. 相似文献
153.
V. Janiš 《Czechoslovak Journal of Physics》1986,36(10):1107-1129
An expansion for generating functionals (partition sums) of models expressed as lattice functional integrals with local (on-site) interactions is presented. This expansion renormalizes the standard perturbative expansion in such a way that certain its terms are summed up non-perturbatively. A non-self-consistent and a self-consistent versions of the expansion are formulated and criteria for an estimation of validity of approximations resulting from the both expansions are given. The simplest approximation being the first term of this expansion is applied to two lattice models: classicalN-component spin model and the model of non-interacting electrons in a disordered crystal. In the former model the critical temperature is calculated within 10% accuracy and in the latter, the coherent potential approximation is obtained. 相似文献
154.
Using real replicas to describe the many-state phase space of the Sherrington-Kirkpatrick model of a spin glass, we rederive the Sompolinsky free energy for the ground state. We propose an interpretation of the order parameter function q(x), x 0,1, from the Sompolinsky free energy directly within the real replica scheme. We also suggest an iterative way of reaching the ground-state (Sompolinsky) free energy within this scheme and present numerical results for the first iteration going beyond the ergodic (replica symmetric) solution.The authors are grateful to the referee for constructive comments leading to improvements in the construction of the Sompolinsky free energy and the following interpretation. 相似文献
155.
V. Janiš 《Zeitschrift für Physik B Condensed Matter》1991,83(2):227-235
We present a general scheme for a construction of mean-field-like theories of itinerant lattice fermions based on solutions to the exactd= grand canonical potential. The general construction is explicitly demonstrated on the exactly solvabled= Falicov-Kimball model. A mean-field zero-temperature behaviour of this sample model is studied quantitatively.Work supported by the A. von Humboldt Foundation. 相似文献
156.
157.
V. Janiš 《Czechoslovak Journal of Physics》1982,32(6):657-660
The analysis of boundary conditions in variational formulation of classical field theory is performed. It is used in the Feynman path integral formulation of quantum theory including non-trivial cases of dynamical symmetry breakdown.Presented at the International Symposium Selected Topics in Quantum Field Theory and Mathematical Physics, Bechyn, Czechoslovakia, June 14–19, 1981. 相似文献
158.
Gábor Benk? Jani Kallioinen Jouko E I Korppi-Tommola Arkady P Yartsev Villy Sundstr?m 《Journal of the American Chemical Society》2002,124(3):489-493
Electron injection from the transition metal complex Ru(dcbpy)(2)(NCS)(2) (dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) into a titanium dioxide nanocrystalline film occurs on the femto- and picosecond time scales. Here we show that the dominating part of the electron transfer proceeds extremely rapidly from the initially populated, vibronically nonthermalized, singlet excited state, prior to electronic and nuclear relaxation of the molecule. The results are especially relevant to the understanding and design of molecular-based photovoltaic devices and artificial photosynthetic assemblies. 相似文献
159.
E. Virtanen A. Valkonen J. Tamminen E. Kolehmainen 《Journal of Molecular Structure》2003,650(1-3):201-212
Single crystal X-ray structures (monoclinic space group P21) for methyl 3-oxo-5β-cholan-24-oate and methyl 3,12-dioxo-5β-cholan-24-oate have been solved and compared with HF/6-31G* optimised structures. In the crystalline packings the side chains are connected with weak OC(sp3)HO-type of interactions between C25–H and C24–O–C25 and the keto ends with weak C(sp3)HO=C-type of interactions between C4–H and O=C3. The orientations of the side chains, which steric configurations are of great importance to the biological activity of the molecules, are compared with the experimental structure of methyl 3-hydroxy-5β-cholan-24-oate. Probable reasons for the observed differences are discussed. In addition, 13C and 17O NMR chemical shifts of methyl 3-oxo-5β-cholan-24-oate and methyl 3,12-dioxo-5β-cholan-24-oate as well as the epimeric methyl 3-hydroxy-5β-cholan-24-oate and methyl 3β-hydroxy-5β-cholan-24-oate have been calculated (DFT/B3LYP/6-311G*) and compared with the experimental values by linear regression analyses. In general, the correspondence between the theoretical and experimental parameters is good or excellent. 相似文献
160.
Václav Janiš Vladislav Pokorný Martin Žonda 《The European Physical Journal B - Condensed Matter and Complex Systems》2016,89(9):197
Behavior of Andreev gap states in a quantum dot with Coulomb repulsion symmetricallyattached to superconducting leads is studied via the perturbation expansion in theinteraction strength. We find the exact asymptotic form of the spin-symmetric solution forthe Andreev states continuously approaching the Fermi level. We thereby derive a criticalinteraction at which the Andreev states at zero temperature merge at the Fermi energy,being the upper bound for the 0-π transition. We show that the spin-symmetricsolution becomes degenerate beyond this interaction, in the π phase, and the Andreevstates do not split unless the degeneracy is lifted. We further demonstrate that thedegeneracy of the spin-symmetric state extends also into the 0 phase in which the solutions with zero andnon-zero frequencies of the Andreev states may coexist. 相似文献