Photocarrier injection and the I-V characteristics of La0.8Sr0.2MnO3/SrTiO3:Nb heterojunctions

Oxide heterojunctions made of p-type L0.8Sr0.2MnO3 (LSMO) and niobium-doped n-type SrTiO3 (STO:Nb) have been fabricated by the pulsed laser deposition (PLD) technique and are characterized under UV light irradiation by measuring the current-voltage, photovoltaic properties and the junction capacitance. It is shown that the heterojunctions work as an efficient UV photodiode, in which photogenerated holes in the STO:Nb substrate are injected to the LSMO film. The maximum surface hole density Q/e and external quantum efficiency gamma are estimated to be 8.3x1012 cm-2 and 11 % at room temperature, respectively. They are improved significantly in a p-i-n junction of LSMO/STO/STO:Nb, where Q/e and gamma are 3.0x1013 cm-2 and 27 %, respectively

A 1200-year record of parrotfish teeth suggests centuries of overfishing in Belize.

Humans have utilized the Mesoamerican Reef for millennia but the effects of prehistorical and historical fishing on this ecosystem remain understudied. To assess long-term trends in reef fish abundance in the central Belizean portion, we used three reef matrix cores from this region to construct a record of parrotfish (Labridae) tooth abundance relative to the total number of all fish tooth subfossils. Parrotfish positively affect reef accretion rates and play a pivotal role in maintaining reefs in a coral-dominated state. Our study examined a 1200-year record across three coral cays: Elbow and Lagoon Cays and Bakers Rendezvous. Despite initial increases of fish tooth abundance at all three cays, declines were observed well before modern reef degradation. At Elbow Cay, an initial decline, likely due to Pre-Columbian Maya fishing, appears to be halted near the time of Spanish arrival. A subsequent decline begins at Elbow and Lagoon Cays likely due to Spanish colonization. The religious practices of the Catholic Spanish and the arrival of English privateers and logwooders likely increased fishing pressure. Bakers Rendezvous shows rapid accretion and parrotfish tooth accumulation as well as high tooth abundances, even as the other two cays show declines. Its sharper, more recent decline is likely the result of either the use of new, more southern fishing territories for Catholic Maya converts, the 1832 founding of Stann Creek Town by the Catholic Garifuna, or an interaction of the two. Our data suggest that the origins of reef degradation began hundreds of years before modern declines

Spin-1/2 Triangular Lattice with Orbital Degeneracy in a Metallic Oxide Ag2NiO2

A novel metallic and magnetic transition metal oxide Ag2NiO2 is studied by means of resistivity, magnetic susceptibility, specific heat and X-ray diffraction. The crystal structure is characterized by alternating stacking of a Ni3+O2 layer and a (Ag2)+ layer, the former realizing a spin-1/2 triangular lattice with eg orbital degeneracy and the latter providing itinerant electrons. It is found that the NiO2 layer exhibits orbital ordering at Ts = 260 K and antiferromagnetic spin ordering at TN = 56 K. Moreover, a moderately large mass enhancement is found for the itinerant electrons, suggesting a significant contribution from the nearly localized Ni 3d state to the Ag 5s state that forms a broad band.Comment: 9 pages, 5 figures, to be published in Rapid Communications, Phys. Rev.

Wisdom of Ben Sira

A philological commentary on the book of Ben Sira accompanied by a full translation of the Greek text in the Septuagint. Similar in content to the book of Proverbs, and though not canonical, but read and studied by the ancient Jewish community, as shown by a considerable quantity of fragments of its Hebrew original discovered in a storage room of a synagogue in Cairo and among the documents discovered in Qumran caves and the Judaean Desert. All these data as well as two ancient Syriac translations have been fully taken into account

極限環境エレクトロニクス実現に向けた界面ケイ酸塩層を有する高移動度SiCMOSFETsの研究

広島大学(Hiroshima University)博士(工学)Doctor of Engineeringdoctora

New Research in Renaissance and Baroque Art

Chair: Dr. Anne H. Muraoka, Department of Art Histor

The Books of Hosea and Micah in Hebrew and Greek

This is a verse-by-verse, text-critical study of two important books out of the Minor Prophets. An English translation by the author is provided alongside its Hebrew original as found in Biblia Hebreaica. The Septuagint text studied is the edition prepared by Ziegler. The main purpose of the monograph is not to discover evidences which could be valuable for reconstructing the original Hebrew text of these books, but to read the LXX as a Greek document of its own, not merely as a translation. Much attention has been directed to a whole range of linguistic issues relating to the Greek and Hebrew grammar and lexicography. Ancient fragments found in the Judaean Desert and Qumran caves of these books in Hebrew and Greek have also been looked at. The book of Hosea has been published in the series La Bible d'Alexandrie, but not that of Micah yet. Unlike this series we have paid only minimum attention to documents such as patristic commentaries from which one can learn how the LXX was interpreted without reference to its Semitic original