Recursos de colección

Hokkaido University Collection of Scholarly and Academic Papers (130.615 recursos)

HUSCAP (Hokkaido University Collection of Scholarly and Academic Papers) contains peer-reviewed journal articles, proceedings, educational resources and any kind of scholarly works of Hokkaido University.

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Mostrando recursos 1 - 17 de 17

  1. Geochemical study on low molecular weight dicarboxylic acids and related compounds in the marine aerosols from the Pacific Ocean

    Hoque, Mir Md. Mozammal
    To better understand the sources and atmospheric processing of organic aerosols inthe remote marine atmosphere, aerosol (TSP) samples were collected over the western NorthPacific (13°14’N-53°37’N and 140°46’E-179°54’W) during May-July 2010, central Pacific(1°59’N-35°N and 171°54’E-90°58’W) during September-October 1999, and North-SouthPacific (3°05’N-34°02’N, 6°59’S-25°46’S and 144°52’E-173°55’W) during February-April1994 and were studied for dicarboxylic acids (C2-C11), ω-oxoacids, pyruvic acid and α-dicarbonyls as well as organic and elemental carbon and water-soluble organic carbon. Overthe western North Pacific, diacids are most abundant followed by ω-oxoacids and α-dicarbonyls. Although the molecular compositions of diacids are generally characterized bythe predominance of oxalic (C2) acid, I found a depletion...

  2. Late Pleistocene and Holocene Glaciations in the Nepal Himalayas and Their Implications for Reconstruction of Paleoclimate

    Asahi, Katsuhiko
    Glacial landforms indicate the existence of the past glaciation, and the limits of glacier extent may suggest paleoclimatic conditions. Nevertheless, the lack of the numerical dating has poorly defined the history of glaciations throughout the Himalayas. In the last decade, new dating techniques were developed and started to be applied to the glacial deposits in the Western Himalayas. The Nepal Himalayas are governed by the strong summer monsoon environments; hence, summer monsoon precipitation plays an important role in glacier nourishment. When the geographical extent of the Himalayas is considered, however, the amount of winter precipitation, which is delivered by the...

  3. Complexation and Photochemical Properties of Azobenzocrown Ethers

    Tahara, Ruriko

  4. Paleoenvironmental changes in late Neogene to early Quaternary in southwestern Hokkaido, Japan : A stratigraphical-micropaleontological elucidation

    Nojo, Ayumu
    Neogene and Quatemary deposits are extensively di stributed in the Oshima Peninsula, southwestern Hokkaido. The sedimentary basin of these strata were split into several smaller basins during late Pliocene, and disappeared by Middle Pleistocene. The Kuromatsunai and Setana Formations, the Pliocene and Pleistocene in this region, have recorded paleoenvironmental changes during this period. In the present study, the author investigated lithostratigraphy of the Kuromatsunai and Setana Formations, their ages assignments based on a K-Ar radiometric analysis and microbiostratigraphic analyses, and the paleoenvironmental changes particularly during the deposition of the upper part of the Setana Formation based on foraminifera, and concluded...

  5. Studies on detection of permafrost structure

    Harada, Koichiro
    Field observations and laboratory experiments were carried out in order to examine the applicability of geoelectrical sounding methods to the detection of the permafrost base. In the laboratory, electrical resistivity values of frozen soils were measured under different temperature and soil moisture conditions in order to develop a reliable model, which was applied to field observation. The experimental results show that the resistivity values of Fujinomori clay, silty clay and clayey silt changed gradually near 0 ℃ with temperature changes due to the presence of unfrozen water. In these soils, the resistivity difference between frozen and unfrozen soils with low...

  6. Mechanisms determining coexistence and exclusion between two co-dominant species in subalpine forests

    Takahashi, Koichi

  7. Synthetic Studies on the Lactosaminoglycan Models : Functionalization of Lactose as an Unused Disaccharide Resource

    Furuike, Tetsuya
    Oligosaccharide resources can be utilized as fine materials to construct further complicated and biologically important glycoconjugates. In addition to the known oligosacchride resources such as cellobiose, maltooligosacchrides, and N,N'-diacetylchitobiose, lactose which is obtainable from whey in large amount should be also highly functionalized and applied for glycoconjugate synthesis. Since this disaccharide contains a precusor of N-acetyllactosamine structure known as an important unit of complex carbohydrates, chemical conversion of lactose to further functional synthons for oligosacchride synthesis seems to be powerful and versatile strategy for glycosciences. The thesis is composed of six chapters. The first chapter describes general introduction to the...

  8. Form drag in quasigeostrophic flow over sinusoidal topography

    Uchimoto, Keisuke
    The relationship between form drag and the zonal mean velocity in steady states is investigated in a very simple system, a barotropic quasi-geostrophic channel with a sinusoidal topography. When a steady solution is calculated by the modi ed Marquardt method keeping the zonal mean velocity constant as a control parameter, the characteristic of the solution changes at a velocity. The velocity coincides with a phase speed of a wave whose wavenumber is higher than that of the bottom topography. For smaller than this critical velocity, a stable quasi-linear solution which is similar to the linear solution exists. For larger than...

  9. Feeding and Ranging Behaviors of Proboscis Monkey Nasalis larvatus in Sabah, Malaysia

    Matsuda, Ikki
    A one-male group (BE-Group) of proboscis monkey Nasalis larvatus consisting of the α-male Bejita, six adult females and some immatures was chosen and focal male and females in BE-Group were followed for a total of 1,968 and 1,539 hours, respectively, along the Menanggul River (which is a tributary of the Kinabatangan River), Sabah, Malaysia, focusing on feeding and ranging behaviors from May 2005 to May 2006. In order to determine the availability and seasonal changes of plant species consumed by the focal monkeys, vegetation surveys were carried out in 2.15 ha along 16 200-500 m trails set up in the...

  10. Seasonal Distribution and Behavior of Loggerhead Sea Turtles in the North Pacific : statistical analysis in relation to environmental oceanographic parameters

    Ikeda, Takayoshi
    Loggerhead sea turtles Caretta caretta nesting off coasts of Japan are known to travel an immense distance throughout their life, however much of their behavior in the open ocean is still not clear. Argos transmitters were attached to 30 turtles, which were either postnesting, headstarted, or bycaught, and their tracks were recorded spanning several months to over a year. Location data were low in quality with nearly 70% of the points having error radii that could not be estimated. As an initial step, the noisy data were smoothed under a systematic set of criteria to remove redundant information and obtain...

  11. Distribution of Mountain Permafrost in the Daisetsu Mountains, Hokkaido, northern Japan

    Ishikawa, Mamoru

  12. Unique Properties of the Inactivated X Chromosome in Mammals Revealed by Cell Hybridization

    Yoshida, Ikuya

  13. A study on growth processes of sea ice in the southern region of the Okhotsk Sea, evaluated from heat budget and sea ice sample analysis

    Toyota, Takenobu

  14. Trophic Interactions among Insectivorous Birds, Herbivorous Insects, and Prants in Temperate Deciduous Forest

    Murakami, Masashi


    Watahiki, Masaaki K.

  16. Factors causing extinction of a freshwater pearl mussel, Margaritifera laevis in Japan (Bivalvia: Unionoida)

    Akiyama, Yoshihiro
    Freshwater bivalves are endangered nowadays the world over. One group of freshwater bivalve, Margaritiferidae is a family that is particularly endangered and is devised for conservation measure in many countries. Life history of unionoida including Margaritiferidae is very unique and their larvae known as glochidia are parasitic to fish and/or amphibians. Accordingly, host and population dynamics of Margaritiferidae are closely related. The major objective of the present study was to clarify the mechanism and cause of extinction of a Margaritiferid, Margaritifera laevis. For the purpose of age estimation, marked mussels were reared in situ for one year and it was...

  17. Short-term flow variations under the control of basal conditions in a temperate valley glacier

    SUGIYAMA, Shin
    This thesis studies how a temperate valley glacier flows under the control of basal conditions. To investigate the influence of basal conditions on the glacier flow field, field measurements were carried out with high temporal resolutions at Lauteraargletscher in the Swiss Alps during the ablation season. The measurements and subsequent data analyses focus on the relationship between surface velocity and subglacial water pressure, surface vertical movement (uplift), and temporal variations in vertical strain. A glacier flow model is developed to study general effects of basal perturbation on the flow field, and is used to interpret the observed short-term flow variations....

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