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Now showing items 129 - 144 of 4663

  • Group divisible designs with block size four and group type g(u)m(1) for more small g

    Wei, Hengjia   Ge, Gennian  

    Non-uniform group divisible designs are instrumental in the constructions for other types of designs. Most of the progress for the existence of {4}-GDDs of type g(u)m(1) is on the case when gu is even, where the existence for small g has played a key role. In order to determine the spectrum for {4}-GDDs of type g(u)m(1) with gu being odd, we continue to investigate the small cases with g is an element of {7, 9, 21} in this paper. We show that, for each g is an element of {7, 9, 21}, the necessary conditions for the existence of a {4}-GDD of type g(u)m(1) are also sufficient. As the applications of these GDDs, we obtain a few pairwise balanced designs with minimum block size 4. Meanwhile, we also improve the existence result for frame self-orthogonal Mendelsohn triple systems of type h(n) by reducing an infinite class of possible exceptions, namely n = 9 and h equivalent to 2 mod 6, to eight undetermined cases. (C) 2013 Elsevier B.V. All rights reserved.
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  • Measurement of L3 to M shell vacancy transfer probabilities of Th and U

    Ertugrul   M.  

    The vacancy transfer probabilities from L 3 to M shell (eta(L 3M)) are obtained for Th and U. For these measurements, L 3 X-ray yields from targets excited by 5.96 and 16.898 and 17.781 keV incident photon, i.e., below and above the L 3 edge of elements. For comparison with experimental results, we have made theoretical calculation using radiative and nonradiative transition rates. The radiative transition rates of these elements were taken from Dirac-Hartree-Slater model of Scofield (1974) and the nonradiative transition rates were obtained from Dirac-Hartree-Slater model of Chen et al. (1979). The measured results are in good agreement with theoretically calculated values
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  • Measurement of L-3 to M shell vacancy transfer probabilities of Th and U

    Ertugrul, M  

    The vacancy transfer probabilities from L-3 to M shell (eta(L3)M) are obtained for Th and U. For these measurements, L3 X-ray yields from targets excited by 5.96 and 16.898 and 17.781 keV incident photon, i.e., below and above the L3 edge of elements. For comparison with experimental results, we have made theoretical calculation using radiative and nonradiative transition rates. The radiative transition rates of these elements were taken from Dirac-Hartree-Slater model of Scofield [1] and the nonradiative transition rates were obtained from Dirac-Hartree-Slater model of Chen et al. [2]. The measured results are in good agreement with theoretically calculated values.
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  • Magnetic properties of U(Ga1?xMx)2 with M=Cu, Al and Ge

    L.M. da Silva   F.G. Gandra   D.P. Rojas   L.P. Cardoso   A.N. Medina  

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  • Der 60. Geburtstag von Professor Manfred A. Hirt (Hrsg.: M. Crisinel u. a.)

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  • Der 60. Geburtstag von Professor Manfred A. Hirt (Hrsg.: M. Crisinel u. a.)

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  • Research and Evaluation for Businessby M. K. Pelosi; T. M. Sandifer; U. Sekaran

    Review by: Paul Hewson  

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  • 238U Mössbauer study of UPt3

    Tsutsui, S.   Nakada, M.   Nasu, S.   Haga, Y.   Yamamoto, E.   Kimura, N.   Onuki, Y.  

    Using Mössbauer spectroscopy, the magnetic properties of UPt3 have been investigated. The Mössbauer spectra in UPt3 shows that the paramagnetic hyperfine interaction is similar to that in UPd2Al3 and URu2Si2. The quadrupole interaction has been observed in the measured temperature range from 2.8 to 125K. Around Tχmax at which the magnetic susceptibility shows a maximum, the spectrum is the sharpest. Although the temperature dependence of the spectra in UPt3 is different from those in UPd2Al3 and URu2Si2, the obtained results suggest that the paramagnetic hyperfine interaction is related to the formation of the heavy fermion state in the 5f-electron system.
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  • On the finiteness properties of U(i)Ass(R)Ext(r)(n) (R/alpha(i),M)

    Khashyarmanesh, K  

    Let alpha be an ideal of a commutative Noetherian local ring R and let M be a finitely generated R-module. Let n be a positive integer such that the support of local cohomology module H-alpha(i)(M) is finite for all i < n. In this note we show that the set ((i is an element of N)Ass(R)Ext(R)(n)(R/alpha(i),M))boolean AND{p is an element of Spec(R):dim R/p > 1} is finite. Also we determine precisely the associated prime ideals p of H-alpha(n)(M) satisfying dimR/p > 1.
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  • Origin of the Electrocardiographic U Wave: Effects of M Cells and Dynamic Gap Junction Coupling

    Bruce Hopenfeld   Hiroshi Ashikaga  

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  • U-CN versus Ce-NC Coordination in Trivalent Complexes Derived from M[N(SiMe3)(2)](3) (M = Ce, U)

    Herve, Alexandre   Bouzidi, Yamina   Berthet, Jean-Claude   Belkhiri, Lotfi   Thuery, Pierre   Boucekkine, Abdou   Ephritikhine, Michel  

    Reactions of [MN3*] (M = Ce, U; N* = N(SiMe3)(2)) and NR4CN (R = Me, Et, or Bu-n) or KCN in the presence of 18-crown-6 afforded the series of cyanido-bridged dinuclear compounds [NEt4][(MN3*)(2)(mu-CN)] (M = Ce, 2a, and U, 2b), [K(18-crown-6)(THF)(2)][(CeN3*)(2)(mu-CN)] (2'a), and [K(18-crown-6)][(UN3*)(2)(mu-CN)] (2'b), and the mononuclear mono-, bis-, and tris(cyanide) complexes [NEt4][MN3*(CN)] (M = Ce, 1a(Et), and U, 1b(Et)), [NMe4]-[MN3*(CN)] (M = Ce, 1a(Et), and U, 1b(Et)), [K(18-crown-6)][MN3*(CN)] (M = Ce, 1'a, and U, 1'b), [(NBu4)-Bu-n](2)[MN3*(CN)(2)] (M = Ce, 3a, and U, 3b), [K(18-crown-6)](2)[MN3*(CN)(2)] (M = Ce, 3'a, and U, 3'b), and [(NBu4)-Bu-n](2)[MN2*(CN)(3)] (M = Ce, 4a, and U, 4b). The mono- and bis(cyanide) complexes were found to be in equilibrium. The formation constant of 3'b (K-3,K-b) from l'b at 10 degrees C in THF is equal to 5(1) X 10(-3), and -Delta H-3'b, = 104(2) kJ mol(-1) and -Delta S-3'b, = 330(5) J mol(-1) K-1. The bis(cyanide) compound 3a or 3h was slowly transformed in solution into an equimolar mixture of the mono- and tris(cyanide) derivatives with elimination of (NBu4N)-Bu-n*. The crystal structures of 1a(Me), 1b(Me), 1'a center dot toluene, 1'b center dot toluene, 2'a, 2'b, 3a, 3'a, 3'b, 3'a center dot 2benzene, 3'b center dot 2benzene, 4a center dot 0.5THF, and 4b center dot Et2O were determined. Crystals of the bis(cyanide) uranium complexes 3'b and 3'b center dot 2benzene are isomorphous with those of the cerium counterparts 3'a and 3'a center dot 2benzene, but they are not isostructural since the data revealed distinct coordination modes of the CN group, through the C or N atom to the U or Ce metal center, respectively. This differentiation has been analyzed using density functional theory calculations. The observed preferential coordination of the cyanide and isocyanide ions toward uranium or cerium in the bis(cyanide) complexes is corroborated by the consideration of the binding energies of these groups to the metals and by the comparison of DFT optimized geometries with the crystal structures. The better affinity of the cyanide ligand toward U-III over Ce-III metal center is related to the better energy matching between the 6d/5f uranium orbitals and the cyanide ligand ones, leading to a non-negligible covalent character of the bonding.
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  • On group-divisible designs with block size four and group-type g(u)m(1)

    Ge, GN   Rees, RS  

    We investigate the spectrum for {4}-GDDs of type g(u)m(1). We determine, for each even g, all values of m for which a {4}-GDD of type g(u)m(1) exists, for every 'fourth' value of u. We similarly determine, for each odd g not equal 11 or 17, all values of m for which a {4}-GDD of type g(u)m(1) exists, for every 'third' value of u. Finally, we establish, up to a finite number of values of u, the spectrum for {4}-GDDs of type g(u)m(1) where gu is even, g is not an element of {11, 17}.
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  • Computational Mechanics for the Next Millennium (Eds.: C. M. Wang u. a.)

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  • The collision-induced I-2(E0(g)(+)->(M)D0(u)(+)) transitions, M = He, Ar, N-2, CF4

    Akopyan, ME   Pravilov, AM   Stepanov, MB   Zakharova, AA  

    The dependences of the I-2 (E-g(+), tau(E), J(E) -->(M) D0(u), v(D), J(D)), M = He, Ar, N-2, CF4, transition rate constants on the vibrational v(E), tau(D), rotational J(E), J(D) quantum numbers, energy gaps, as well as their correlations with Franck-Condon factors of the initial and final levels have been studied. Intramolecular transitions induced by the C-3/R-3 term of multipole series of potential energy operator instantaneous dipole (I-2(E-D) optical transition) - instantaneous dipole (vibrational transitions in CF4 molecule) have been found out and discussed. The collision-induced intramolecular transitions observed in this and our previous works [Chem. Phys. 242 (1999) 263, 263 (2001) 459 and Chem. Phys. 277 (2002) 179] have been classified. (C) 2002 Elsevier Science B.V. All rights reserved.
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  • Soft magnetic properties of amorphous-CoZr/ polycrystalline-M (M”鈥塁u, Ag, Al, Cr) multilayers

    X.W. Li   C. Song   R.L. Zong   F. Zeng   J. Yang   S.P. Wen and F. Pan  

    This study examines the microstructures and magnetic properties of (CoZr10 nm/M10 nm)20 (M=Cu, Ag, Al, Cr) multilayers prepared by direct current magnetron sputtering. The structural characterizations show that CoZr layers have an amorphous structure, but a slight dissimilarity of local structure exists among the amorphous phases, which is most likely affected by the different polycrystalline M layers. Consequently, the soft magnetic properties of (CoZr10 nm/M10 nm)20 multilayers are strongly dependent on the non-magnetic M layers. On the other hand, an in-plane uniaxial magnetic anisotropy is observed for all multilayers, which can be attributed to the tensile stress induced by sample rotation during film deposition. A combination of Cu serving as non-magnetic layers and tensile stress is the key to enhancing the soft magnetic properties of CoZr-based films. The mechanisms responsible for the dependence of the magnetic properties on non-magnetic M layers and tensile stress are discussed.
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  • Magnetic structure of MFe4Al8, M = Y and U: a comparative study

    C Cardoso   T Gasche   M Godinho  

    In this paper we present a comparative analysis of the isostructural compoundsMFe4Al8, withM = Y andU. These compounds have different magnetic ground state structures: a cycloid spin spiral in the caseof YFe4Al8 and a canted structure in the case of the actinide compound. Model calculations show thatit is the presence of a strong spin–orbit coupling in the actinide compound thatleads to a magnetic configuration with symmetry properties that differ from theYFe4Al8 cycloid structure. Furthermore we show that in the absence of spin–orbit coupling, the U compoundwould have the same spin spiral as the Y compound. A further analysis for two actinide compounds,UFe4Al8 and NpFe4Al8, point to similar magnetic ground state structures; however the actinides play differentroles in the magnetisms of the two compounds. Despite their differences, all three magneticstructures can be seen as deviations from the type G antiferromagnetic structure.
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