Bulgarian Academy of Sciences

About: Bulgarian Academy of Sciences is a government organization based out in Sofia, Bulgaria. It is known for research contribution in the topics: Catalysis & Coupling constant. The organization has 17989 authors who have published 36276 publications receiving 642820 citations. The organization is also known as: Bulgarian Academy of Sciences，簡稱：BAS & Balgarska Akademiya na Naukite.

Locus of control and well-being at work: how generalizable are western findings

Abstract: Managers from 24 geopolitical entities provided data on work locus of control, job satisfaction, psychological strain, physical strain, and individualism/collectivism. The hypothesis that the salut...

Observation of sequential Υ suppression in PbPb collisions

Abstract: The suppression of the individual Υ(nS) states in PbPb collisions with respect to their yields in pp data has been measured. The PbPb and pp data sets used in the analysis correspond to integrated luminosities of 150 μb^(-1) and 230 nb^(-1), respectively, collected in 2011 by the CMS experiment at the LHC, at a center-of-mass energy per nucleon pair of 2.76 TeV. The Υ(nS) yields are measured from the dimuon invariant mass spectra. The suppression of the Υ(nS) yields in PbPb relative to the yields in pp, scaled by the number of nucleon-nucleon collisions, R_(AA), is measured as a function of the collision centrality. Integrated over centrality, the R_(AA) values are 0.56±0.08(stat)±0.07(syst), 0.12±0.04(stat)±0.02(syst), and lower than 0.10 (at 95% confidence level), for the Υ(1S), Υ(2S), and Υ(3S) states, respectively. The results demonstrate the sequential suppression of the Υ(nS) states in PbPb collisions at LHC energies.

Comparative study of optical phonons in the rhombohedrally distorted perovskites LaAlO 3 and LaMnO 3

Abstract: The Raman and infrared phonons of isostructural rhombohedral ${\mathrm{LaMnO}}_{3}$ and ${\mathrm{LaAlO}}_{3}$ are studied at room temperature. The experimental spectra are compared with the prediction of lattice-dynamical calculations and the lines observed are assigned to definite atomic vibrations. It is shown that the Raman mode of ${A}_{1g}$ symmetry in ${\mathrm{LaAlO}}_{3}$ and ${\mathrm{LaMnO}}_{3}$ (at $123 {\mathrm{cm}}^{\ensuremath{-}1}$ and $236 {\mathrm{cm}}^{\ensuremath{-}1},$ respectively) involves atomic motions that cause the rhombohedral distortion, i.e., it is a ``soft'' mode, and its position could be used as a measure of the degree of the distortion. It is also argued that the broad Raman bands in the high-frequency range of ${\mathrm{LaMnO}}_{3}$ are not proper modes of the rhombohedral $R3\ifmmode\bar\else\textasciimacron\fi{}c$ structure, but are rather induced by the dynamic Jahn-Teller effect.

FT-IR study of NO + O2 co-adsorption on H-ZSM-5: re-assignment of the 2133 cm-1 band to NO+ species

Abstract: Whereas NO adsorption at room temperature on activated H-ZSM-5 (Si/Al = 29) caused only negligible changes in its IR spectrum, addition on O2 to NO led to the appearance of bands at 2133 and 977 cm-1. Concomitantly, the number of acidic zeolite OH groups decreased while H2O hydrogen-bonded to zeolite OH groups developed. Introduction of small amounts of 18O2 did not change the 2133 cm-1 band wavenumber, nor the use of a partly deuteroxylated D–H-ZSM-5 sample. In such a case, HOD formation was detected. The results obtained evidence that the 2133 cm-1 band, generally considered as characterizing NO+2 species, is, in fact, due to NO+ species occupying cationic positions in the zeolite. The 977 cm-1 band is attributed to the Olattice–NO+ vibration. A scheme of the NO+ formation, involving NO2 molecules as NO oxidizing agent, is proposed.