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Ziguinchor, Senegal

Sakhoa I.,University of Ziguinchor
European Physical Journal D | Year: 2010

We present in this paper autoionizing energies of the 1P̊ states of H- and He belonging to the N = 3-13 hydrogenic thresholds. Calculations are performed for both intershell and intrashell resonances using the screening constant by unit nuclear charge (SCUNC) method in the framework of a semi-empirical procedure. The results obtained in this paper agree very well with available theoretical and experimental values. These agreements point out the possibility to use the SCUNC method in the study of other Rydbergtype series in doubly excited states of He-positive like ions. © EDP Sciences, Societá Italiana di Fisica, Springer-Verlag 2010. Source


Sakho I.,University of Ziguinchor
Chinese Journal of Physics | Year: 2014

We present in this paper non-relativistic energies of the 1s2ns2S (n = 3-20) and 1s2np 2P (n = 2-20) excited states of the lithium-like ions using the screening constant by unit nuclear charge method. Calculations are performed up to Z = 20. In addition, high precision results for the fine structure splitting of the 1s2np 2P (n = 3, 4, and 5) levels of Z = 3-20 including quantum electrodynamics (QED) corrections are obtained, taking into account the solution of the Dirac relativistic equation of the hydrogen-like systems with the effective nuclear charge Z* = Z(1 - β), β being the screening constant by unit nuclear charge. It is shown that QED corrections are very significant for large Z systems, and then they should be included in any calculation for obtaining more accurate results. The present data agree very well with the experimental values from NIST and with various calculations. © 2014 The physical society of the republic of china. Source


The 2(1,0)+ n 1S e,2(1,0)- nS e, 2 (1,0) -1P0, 2(1,0) + n 3P0, 2(0,1) + n, 2 (0,1)+ 1 3P0, 2(1,0)+1 nDe and 2(1,0)-3 nDe intershell autoionizing states of the helium-like ions are studied using the screening constant by unit nuclear charge (SCUNC) method in the framework of a semi-empirical procedure. The results up to Z = 10 compared well to the available experimental and theoretical literature data. In addition, the possibility to apply the SCUNC method in the calculations of energy resonances of heavy-Z helium-like ions is demonstrated in the present work where energy positions for some low-lying 2sns 1S e, 2snp 1P0 and 2pnp 1D e (n≥ autoionizing states with 11 ≥Z ≥28 are tabulated and comparison with double sums over the complete hydrogen spectrum calculations [A.I. Ivanov, I.U. Safronova, Opt. Spectrosc. 75, 506 (1993)] is made. A host of results presented in this paper may be useful guideline for future experimental and theoretical investigations in high-lying 1,3Se, g 1,3S eP0 and 1,3De De doubly excited states as well as in lower than in heavy-Z two-electron systems. © 2010 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg. Source


Sakho I.,University of Ziguinchor
Chinese Journal of Physics | Year: 2013

We report in this paper on the ENn energy resonances of the doubly excited 1P° states of H- and He below the N = 4-10 threshold of H and He+, applying the modified orbital atomic theory in the framework of a semi-empirical procedure. The calculated energy levels are specified in terms of the supermultiplet classification scheme based on the new notations N(K, T)A n and N(ν)A n in the framework of the rovibrator model for the autoionizing states considered. Comparison of the N 〈r-1 12〉n radial expectation values of H- and He indicates that the angular quantum number K is effectively related to -〈cosθ12〉, with θ12 being the angle between the position vectors of the two electrons. In addition, comparison of the radial expectation values of H- and He shows that, for both intrashell and intershell N(K, T)A n, 1P° states, it is the Coulomb force which causes the differences observed in the photoabsorption spectra of H- and He. All the results presented in this work compared well with the available literature values. © 2013 The Physical Society Of The Republic Of China. Source


Pagnoux-Ozherelyeva A.,CNRS Laboratory of Molecular and Thio-Organic Chemistry | Pannetier N.,CNRS Laboratory of Molecular and Thio-Organic Chemistry | Mbaye M.D.,CNRS Laboratory of Molecular and Thio-Organic Chemistry | Mbaye M.D.,University of Ziguinchor | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2012

An aminated series: A well-defined iron-catalyzed reductive amination reaction of aldehydes and ketones with aliphatic amines using molecular hydrogen is presented. Under mild conditions, good yields for a broad range of alkyl ketones as well as aldehydes were achieved. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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