Symmetry Classes of Spin and Orbital Ordered States in a t_{2g} Hubbard Model on a Two-dimensional Square Lattice

This paper presents symmetry classes of the Hartree-Fock (HF) solutions of spin and orbital ordered states in a t_{2g} Hubbard model on a two-dimensional square lattice. Using a group theoretical bifurcation theory of the Hartree Fock equation, we obtained many types of broken symmetry solutions which bifurcate from the normal state through one step transition in cases of commensurate ordering vectors Q_0=(0,0), Q_1=(\pi,\pi), Q_2=(\pi,0) and Q_3=(0,\pi). Each broken symmetry state is characterized by the presence of local order parameters(LOP) at each lattice site: quadrupole moment Q=(Q_2^2,Q_{12},Q_{23},Q_{31}), orbital angular momentum l=(l_1,l_2,l_3), spin density s=(s^1,s^2,s^3), spin quadrupole moment Q^{\lambda}=(Q_2^{2\lambda}, Q_{12}^{\lambda},Q_{23}^{\lambda},Q_{31}^{\lambda}) and spin orbital angular momentum l^{\lambda}=(l_1^{\lambda},l_2^{\lambda},l_3^{\lambda}) where \lambda=1,2,3. We performed numerical calculations for some parameter sets. Then we have found that many types of non-collinear magnetic orbital ordered states having LOP:Q^{\lambda} and l^{\lambda} can be the ground state for these parameter sets.Comment: 46 pages with 4 figure

Marine Exploitation at South Point, Hawai'i Island: An Aspect of Adaptive Diversity in Hawaiian Prehistory.

Island ecosystems have several significant characteristics, such as relative isolation, limitation in size, limitation in or even absence of certain resources, limitation in organic diversity, etc. (Fosberg 1965). Therefore, man in the island ecosystem must cope with several stresses, among which food is the most substantial. Food resources in the Pacific are usually limited quantitatively and qualitatively. Quantitatively, the amount of food is limited by land area; in other words, there is a clear carrying capacity in island ecosystems. Qualitatively, animal protein on islands is limited due to the general absence of mammals in the Pacific islands. Both quantitative and qualitative limitations in terrestrial food resources have led to an emphasis on exploitation of marine resources. Marine resources have been well preserved by traditional conservation mechanisms (Johaness 1978; 1981), and marine exploitation has worked to increase man's adaptability to the Pacific environment

Determination of Molybdenum in Iron and Steel with Vacuum Spectrometer

In the direct-reading spectrometric determination of molybdenum, the overlapping spectral lines of nickel and manganese often interfere with analytical results. In this paper, analytical lines of molybdenum, Mo II 2038.46 A and Mo II 2020.32 A, are newly proposed, making use of iron line Fe II 1761.38A as an internal standard. With these spectral lines, interfering elements, excitation conditions, and reproducibility of the results were investigated. The best results were obtained under the excitation of the critically damped discharge of a low voltage condenser spark. The overlapping line of manganese slightly interfered with Mo II 2038.46A. With Mo II 2020.32 A, which had no interfering element, 0.20% and 1.09% of molybdenum in low alloy steels were determined with the variation coefficients of 2.2% and 1.6%, respectively

Business-Academia-Government Collaboration in Developing Human Resources in Science and Technology: Lessons from the Case of Britain (Japanese)

Japanese industry has finally emerged from the prolonged economic slump and, partly helped by expanded tax incentives, companies have begun to accelerate research on and development of future technologies. In order to achieve this goal, Japan needs to secure and develop human resources for R&D. In this paper, we examine Britain's approach to the development of human resources through cooperation among business, government and academia, which has been praised as the "best practice" of its kind. Then, drawing on the case of Britain, we explore policy measures for developing human resources in science and technology which also promote technology transfer from universities to industry via people, thereby laying a foundation for competitiveness.

Indigenous Boat-Hull Making in the Circum-Pacific:An Overview of Primodial Technology in the Tropical and Sub-tropical Zones

本稿は環太平洋の熱帯・亜熱帯域を中心に伝統的な舟の船殻形成について概観するものである。原初的な舟としては（1）筏と葦舟（raft and reed boat）、（2）皮舟ないし獣皮舟（skin boat）、（3）樹皮舟（bark boat）、および（4）刳り舟（dugout canoe）の４系統が考えられる。まず西村真次にそって古代日本にも丸木舟以外に多様な舟の船殻形成法があったことを指摘する。そして比較の視野を広げ、環太平洋地域熱帯・亜熱帯部における伝統的な船について文献、博物館資料および現地調査に基づき報告する。対象としたのは、オーストラリアと南米における樹皮舟、南米の葦舟、そして東南アジア・オセアニアおよび南米の筏である。そして最後にコンチキ号以来の復元船による航海実験にもふれ、近年発見が増加している琉球列島の旧石器文化を残した人類は、どのような船を使って琉球列島あるいは日本列島に海を渡ってきたかについて考察する

Technology in Process: From the History of American Material Culture Studies

研究ノー

Technological Interaction of Traditional Boat Building in the Circum-Pacific Area －Outrigger Fishing Boats on the Bonin Islands and the Hachijo-jima Island－

環太平洋海域には筏、カヌー、カヤックをはじめ多様な舟が使用されてきた。それはモンゴロイド集団の移動と一部重なることを見れば、人類移動の大きな枠組みの中で捉える必要が確認できる。舟の多くは海の常民たる海人・海民集団の生存に対する必須アイテムであり、比較研究が望まれる。また海の世界は陸上世界とは異なったスケールの技術移転と複合が起りうるという特徴が指摘できる。本稿ではその具体的事例としてハワイ王国から伝わったアウトリガー式漁船が小笠原諸島と八丈島でどのように日本の伝統と融合したかを明らかにしたい。研究ノー