[en] Many 3d transition-metal oxides can be doped with electrons or holes and can be made metallic. We investigate the electronic structure of pseudo-ternary oxides in the charge-transfer and Mott-Hubbard regimes by photoemission, inverse photoemission, and X-ray absorption spectroscopy. In most cases, mid gap-states are formed upon carrier doping whereas in some cases they are not. Both electron correlation and impurity potential play an important role in the formation of mid-gap states. (orig.)

[en] Full text: The gene of catalytic subunit of DNA dependent protein kinase is responsible gene for SCID mice. The molecules play a critical role in non-homologous end joining including the V(D)J recombination. Contribution of the molecules to the difference of radiosensitivity and the susceptibility to cancer has been suggested. Here we show the entire nucleotide sequence of approximately 193 kbp and 84 kbp genomic regions encoding the entire DNA-PKcs gene in the mouse and chicken respectively. Retroposon was found in the intron 51 of mouse genomic DNA-PKcs gene but in human and chicken. Comparative analysis of these two species strongly suggested that only two genes, DNA-PKcs and MCM4, exist in the region of both species. Several conserved sequences and cis elements, however, were predicted. Recently, the orthologous region for the human DNA-PKcs locus was completed. The results of further comparative study will be discussed

[en] The x-ray photoemission spectra of Pr, PrHsub(2.1) and PrH₃ have been measured. The core levels of PrH₃ show satellites due to H 1s → Pr 4f transitions, which become weaker in PrHsub(2.1). PrHsub(2.1) exhibits satellites due to Pr 5d → Pr 4f transitions and those due to the empty localised 5d level. Taking these satellite structures into account, chemical shifts between PrHsub(2.1) and PrH₃ are ambiguous while there are large chemical shifts between Pr and PrHsub(2.1), implying that a charge transfer occurs from Pr to tetrahedral hydrogen but not to octahedral hydrogen. A hydrogen-induced band appears at about 6 eV below the Fermi energy, and comparison with theoretical densities of states suggests the importance of hybridisation between Pr 6sp and H 1s in the metal-hydrogen bonding. (author)

[en] The symmetry and site distribution of doped oxygen holes are studied using the CuO/sub n/ cluster model. For reasonable values of the on-site Coulomb interaction, charge transfer energy, and hybridization, the holes are found to enter pσ/sub x//sub ,//sub y/ orbitals in the CuO₂ plane to form local singlets with the Cu d⁹ spins when the energy difference between the in-plane and off-plane (BaO) oxygen levels is small, whereas the holes are distributed both in the CuO₂ and BaO planes and form local triplets when the BaO oxygen energy level is high enough (by approx. >1.7 eV). We argue that the latter situation may occur in high-T/sub c/ superconductors and may be related to the occurrence of superconductivity

[en] We have studied the electronic structure of the Mn-based diluted magnetic semiconductors and the ordered Mn surface alloys using photoemission spectroscopy and configuration interaction (CI) calculation. As for the Mn-based diluted magnetic semiconductors, the electronic-structure parameters obtained from the CI analysis show systematic variation with expected chemical trends. The CI picture gives a systematic description of the d-d absorption spectra, the exchange constants between the 3d spins and host band states, and the donor and acceptor ionization energies of the diluted magnetic semiconductors. The photoemission spectra of the ordered surface alloys CuMn/Cu(1 0 0) and NiMn/Ni(1 0 0) show correlation satellites similar to the impurity Mn atom in solids. It is shown that the CI analysis can describe the correlation satellites driven by the reduced dimensionality in the ordered surface alloy systems

[en] The electronic structure of Cu-oxide superconductors revealed by photoemission spectroscopy combined with configuration-interaction cluster model analyses is reviewed. In particular, the results of recent cluster calculations suggest that under certain conditions the doped holes enter oxygen sites in the BaO (or Lao, SrO) planes as well as those in the CuO₂ planes and are weakly coupled to the Cu d⁹ spins through ferromagnetic interaction. Implications of these results on various pairing mechanisms are discussed. Importance of long-range Coulomb interaction manifested in the photoemission spectra is pointed out

[en] In this paper, the authors measure photoemission spectra of single crystal BaPb_1-xBi_xO₃ at liquid nitrogen temperature. Clear Fermi edges have been observed in the valence band spectra for metallic compositions. The valence band peak dominated by O 2p states does not show a rigid band shift with x. The gross features in the experimental density of states (DOS) agrees well with calculated DOS in the insulating phase rather than in the metallic phase

[en] Structural phase transitions in WO₃ and the stability of cubic ReO₃ and Msub(x)WO₃ lattices are attributed to the screening effect involving W or Re 5d and O 2p states on the lattice vibrations. The presence of the conduction electrons in ReO₃ or Msub(x)WO₃ is shown to suppress this effect and to stabilize the cubic lattice. (author)

[en] The electronic structure of CeHsub(x) (2 < approximately x <= 3) has been calculated with the hydrogen atoms occupying various octahedral sites of the FCC lattice to represent non-stoichiometric compositions (x = 2, 2.25, 2.5, 2.75 and 3) by using the LCAO method. It is shown that defect levels due to the hydrogen vacancies in CeHsub(approximately3) act as electron donors and that a defect band is formed for CeHsub(approximately 2.7). A possible mechanism of the temperature-dependent metal-semi-conductor transition in CeHsub(approximately 2.7) is presented. (author)

[en] The Raman active phonon in CeHsub(approximately 3) is anomalously soft as compared with that in in CeHsub(approximately 2). It is shown that this can be attributed to enhanced electron-phonon interactions arising from changes in the electronic structure with composition: when going from CeH₂ to CeH₃ a new s-like valence band is formed, and the valence electrons screen the Raman active mode via virtual transitions into Ce d states. Frequency renormalisation due to the electron-phonon interaction has been calculated from the electronic energy bands. (author)