| 1. |
- Sandell, A., et al.
(författare)
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THE INNER VALENCE REGION OF CO ADSORBED ON PD(100)
- 1994
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Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 26:19, s. 10659-10668
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Tidskriftsartikel (refereegranskat)abstract
- The inner valence region of CO/Pd(100) p(2square-root2 x square-root2)R45-degrees has been studied by angular resolved photoemission at the Pd 4d Cooper minimum, and with resonant Auger spectroscopy at photon energies corresponding to the C 1s and O 1s x-ray absorption (XA) maxima of the unoccupied parts of the 2pi*-Pd 4d hybrid (2pi(un)). Previously unobserved inner valence states are revealed in the direct photoemission and are compared with resonant Auger results. The interpretation and assignment of the different spectral features to different main final state configurations are based on energy, symmetry and intensity arguments, as well as comparisons with previous results.
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| 2. |
- Andersen, Jesper N, et al.
(författare)
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Photoemission Spectroscopy At Max-Lab
- 1991
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Ingår i: Synchrotron Radiation News. - : Informa UK Limited. - 0894-0886 .- 1931-7344. ; 4:4, s. 15-19
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Nilsson, A., et al.
(författare)
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Photoabsorption and the unoccupied partial density of states of chemisorbed molecules
- 1992
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 197:1-2, s. 12-16
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Tidskriftsartikel (refereegranskat)abstract
- The 1s to 2π* resonances have been studied for CO strongly chemisorbed on Ni(100) and weakly chemisorbed on Cu(100) using high resolution X-ray absorption spectroscopy. We show that the spectra can be consistently described in terms of the local density of unoccupied 2π* electron states with the Fermi level obtained from corresponding X-ray photoelectron spectra. The core hole is demonstrated to induce large shifts in the unoccupied 2π* density of states.
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| 4. |
- Zdansky, E. O F, et al.
(författare)
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Electronic structure of atomic adsorbates from x-ray-absorption spectroscopy : Threshold effects and higher excited states
- 1993
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Ingår i: Physical Review B (Condensed Matter). - 0163-1829. ; 48:4, s. 2632-2641
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Tidskriftsartikel (refereegranskat)abstract
- Atomic C, N, and O chemisorbed on Ni(100) have been studied by x-ray-absorption spectroscopy. The atomic 2p orbitals are shown to form hybrid orbitals with the Ni 3d and 4sp bands. The spectral contributions from these hybrids are identified at the absorption threshold and in a region 6-12 eV above this. Between those regions, states derived from atomic 3p and higher np orbitals are observed. The threshold region shows vibrational and dynamical effects, which are discussed in connection with the corresponding photoemission spectra. The substrate Ni 2p3/2 x-ray-absorption spectrum is also presented. Its large similarity to the Ni 2p3/2 x-ray photoemission spectrum is discussed.
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| 5. |
- Björneholm, O., et al.
(författare)
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Resonant photoemission at core-level shake-up thresholds : Valence-band satellites in nickel
- 1990
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Ingår i: Physical Review B (Condensed Matter). - 0163-1829. ; 41:15, s. 10408-10412
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Tidskriftsartikel (refereegranskat)abstract
- Three-hole satellites (3d7 final-state configuration) in the nickel valence-band photoelectron spectrum have been identified at 13 and 18 eV binding energy with use of synchrotron radiation from the MAX storage ring. The three-hole satellites show resonances at photon energies close to the threshold for excitation of 3p53d9 core-hole shake-up states. The 13-eV satellite also shows a resonance directly at the 3p threshold. This is interpreted as an interference between the direct three-hole ionization and a shake-up transition in the Auger decay of the 3p hole. This shake-up process is also identified directly in the M2,3M4,5M4,5 Auger spectrum.
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| 6. |
- Jensen, K G, et al.
(författare)
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Effects of organotin compounds on mitosis, spindle structure, toxicity and in vitro microtubule assembly.
- 1991
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Ingår i: Mutagenesis. - 0267-8357. ; 6:5, s. 409-16
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Tidskriftsartikel (refereegranskat)abstract
- Di- and tri-methyl, -butyl and phenyl tin, all as chlorides were tested for toxicity and spindle disturbances in V79 Chinese hamster cells and for effects on in vitro assembly of bovine brain tubulin. The V79 cells were treated for 30 min and in general, loss of a stainable spindle could be demonstrated at slightly higher concentrations than c-mitosis. Both these effects were observed at low, non-toxic concentrations. The c-mitotic activity of the compounds was found to increase with increasing lipophilicity and it was best described by a regression on both lipophilicity (partition coefficient octanol/water) and loss of spindle stain. All compounds showed a concentration dependent inhibition of microtubule assembly and all but diphenyltin induced disassembly of preassembled microtubules. An effect on the rate of polymerization was suggested for tributyl- and triphenyltin. The results further indicate that the inhibition of microtubule assembly is through direct interaction with tubulin but does not involve the sulfhydryls of the protein. Thus, the organotins seem to act through two different cooperative mechanisms, inhibition of microtubule assembly and interaction with hydrophobic sites. The latter mechanism might involve Cl-/OH- exchange across cellular membranes. Previous studies have demonstrated chromosomal supercontraction and aneuploidy in human lymphocytes exposed to low concentrations of organotin in vitro and it is suggested that exposure to these compounds may increase the risk of aneuploidy in humans.
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