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31.
Mohammad Basyuni Hirosuke Oku Shigeyuki Baba Kensaku Takara Hironori Iwasaki 《Journal of Oceanography》2007,63(4):601-608
Isoprenoids in the nonsaponifiable lipids (NSL) fraction of Okinawan mangroves were analyzed with special reference to their
importance as lipid input into estuarine ecosystems. Triterpenoids and phytosterols comprised the major proportion of NSL.
Identifications of the triterpenoids and phytosterols in NSL fraction were based on the interpretation of 13C-NMR and GC-MS spectra. The triterpenoids and phytosterols mainly comprised 11 and 6 compounds, respectively. The major components
were lupeol, β-amyrin and taraxerol for triterpenoids, and β-sitosterol and stigmasterol for phytosterols. The diversity in
the terpenoid composition was noted in both leaves and roots of mangrove species, implying the chemotaxonomic utility of terpenoids.
Terpenoid compositions of the root are not always similar to that of leaf, suggesting that terpenoids in the root are produced
by biosynthesis in situ, not by translocation of the synthate from the leaf. Terpenoids existed in greater proportion in the
outer parts of the root. These data are likely to contribute to estimating the lipid input from mangrove trees adjacent to
estuarine sediments and the ocean. 相似文献
32.
Recent experiments on the olivine-spinel phase transformation in Ni2SiO4 have provided the following fundamental results: (1) the interphase structural orientation relationships with between the olivine and spinel phases upon transformation; and (2) the growth of 300 μm spinel single crystal from single crystals of olivine. In the light of these observations, transformation mechanisms proposed have been compared. We conclude that neither a nucleation and growth model nor a martensite model is verified by the experimental results. The former model lacks consistency in terms of the interphase relationships, and the latter cannot offer a dislocation-multiplication mechanism for the growth process. 相似文献
33.
Masayuki Saigusa Kazushi Oishi Akihiro Ikumoto Hiroshi Iwasaki Michihiro Terajima 《Journal of Oceanography》2000,56(3):295-310
The emergence of small arthropods was studied in the boreal sea, Japan (Akkeshi, Hokkaido). In the shallow subtidal zone, two impeller pumps were set in the surface and bottom waters. The pumps ran continuously for 25 days (22 August-16 September, 1998), and invertebrates were sampled using a nylon net (300 to 500 m in mesh size). The small arthropods collected with the net belonged to 16 orders comprising about 60 taxa. In the dominant 23 taxa, a two-way ANOVA was applied to determine whether there was any significant difference in abundance between day and night and between surface and bottom. While emergence of 15 taxa (65%) was significantly different with regard to the day/night factor, that of the other 8 taxa (35%) was not. As to the difference between the two depths, the distribution of 15 taxa (65%) was significantly different. Furthermore, in 25 taxa for which over 100 specimens were collected in each of the two depths of water, emergence patterns were examined with regard to the synchrony with day/night and tidal cycles. There were various nocturnal patterns, and the strength of the synchrony with the day/night cycle was different for each species or group. Within the same taxa, nocturnal patterns were more clearly manifested in the surface water than in the bottom water. A tidal rhythm of emergence was only seen in zoeas of shrimp. Variations of the emergence patterns of benthic crustaceans are accounted for by a hypothesis that the frequency of swimming during day versus at night is different in each species. On the other hand, the emergence patterns of some zooplankton reflect by the daily rhythm of vertical migration or dispersal in the water column. 相似文献
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Bulletin of Volcanology - The results obtained from the study of the Atami Geyser. of Hakone Volcano fumaroles, and of Kagai hot springs can be used for the geochemical prediction of ‘great... 相似文献
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We examined how and why dominant peak-flow runoff-generation mechanisms differ among neighbouring headwater catchments. We monitored runoff and groundwater levels and performed terrain analyses in a granitic second-order catchment and its four neighbouring subcatchments in the Kiryu Experimental Watershed in Japan. Our analysis of lag times from peak rainfall to peak runoff suggests differences in the dominant peak-flow runoff-generation mechanisms among the five catchments. For two of the three zero-order catchments, with few perennial groundwater bodies, subsurface flow from hillslopes was the dominant mechanism at some events. However, the dominant mechanisms were channel precipitation and riparian runoff at almost all events in first- and second-order catchments and in the third zero-order catchment, which has a large perennial groundwater body over a bedrock depression in the riparian zone. In this zero-order catchment, the quick-flow ratio was the smallest of the five catchments because subsurface flow from the hillslope was buffered at the riparian zone. These facts suggest that the channel length, riparian buffering, and hillslope connectivity were the factors governing the different dominant peak-flow runoff-generation mechanisms among the catchments. Riparian buffering was affected, not only by surface topography, but also by bedrock topography and bedrock groundwater (BGW) dynamics. Our findings indicate that both of BGW dynamics and topography are important for catchment classification, and the relative importance of topography increases with the change from baseflow to stormflow. Furthermore, mismatching between a geographic source and a flow path resulted in different catchment classifications depending on the approach. Therefore, multiple approaches during both baseflow and stormflow periods are necessary for catchment classification to apply information obtained from one headwater catchment to other headwater catchments within the same region. 相似文献
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It is important to know the shape of a subducting slab in order to understand the mechanisms of inter-plate earthquakes and the process of subduction. Seismicity data and converted phases have been used to detect plate boundaries. The configuration of the Philippine Sea slab has been obtained at the western part of southwestern Japan. At the eastern part of southwestern Japan, however, the configuration of the Philippine Sea slab has not yet been confirmed. A spatially high-density seismic network makes it possible to detect the boundaries of the Philippine Sea slab. We used a spatially high-density temporal seismic array in the area. The configuration of the Philippine Sea plate is obtained at the eastern part of southwestern Japan using the temporal seismic array and permanent seismic network data and comparing the seismic structure obtained from the results of refraction surveys. The configuration of the Philippine Sea plate obtained by this study does not bend sharply compared to previous models obtained from receiver function analyses. We delineated the upper boundary of the slab to a depth of about 45 km. The weak image of the boundary, which corresponds to the upper mantle reflector beneath the source area of the 2000 Western Tottori earthquake, was detected using the spatially dense array. 相似文献