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81.
Akihiro Shiomoto Katsuyuki Sasaki Toru Shimoda Satsuki Matsumura 《Journal of Oceanography》1994,50(5):515-529
The maximum uptake rate (max) and affinity constant (K
s) for nitrate and ammonium were estimated in the surface water of offshore Oyashio in May (spring) and September (summer), 1990. The average max/Chl.a for ammonium was 2.1 times larger than that of nitrate in both seasons. The average max/Chl.a for both nitrogens were 3.5 times larger in summer than in spring. Water temperature and size composition of phytoplankton population were related to the seasonal difference in the max/Chl.a. Phytoplankton population showed high affinity for both nitrogens in the spring and summer. In addition, the contribution of new production to total production was estimated by max[max–No3/(max–NO3+max–NH4)]. The spring value was in the range of 0.26 to 0.45 (mean±SD=0.35±0.092), and the values in spring bloom were especially a little over 0.4. The summer value was in the range of 0.30 to 0.37 (0.34±0.04). 相似文献
82.
Tsuneo?OnoEmail author Hiromi?Kasai Takashi?Midorikawa Yusuke?Takatani Kazuhiro?Saito Masao?Ishii Yutaka?W.?Watanabe Katsuyuki?Sasaki 《Journal of Oceanography》2005,61(6):1075-1087
Eight-year observation results of DIC from 1996 to 2003 in the Oyashio region have been analyzed to obtain a climatological
view of its seasonal variation and interannual variation. Data of DIC obtained by several institutes are synthesized to give
a dataset with an uncertainty lower than 5 μmol/kg. The obtained climatology of NDIC seasonal variation in the Oyashio mixed layer shows a seasonal amplitude of 176 μmol/kg, with a maximum in January and a minimum in September. These features closely resemble those observed in the southern
half of the western subarctic North Pacific (WSNP) including Station KNOT, although the timing of the NDIC maximum is slightly
advanced in the case of the Oyashio. Analysis using a quasi-conservative tracer Cp0 (NDIC - 106NP) shows that among 176 μmol/kg of NDIC seasonal variation, only 16 μmol/kg is attributed to hydrographic processes while the remaining 160 μmol/kg is attributed to biological processes. The Cp0 value in the Oyashio mixed layer also resembles that of the WSNP mixed
layer during the months May to November, suggesting further resemblance of the Oyashio water mass to that of WSNP in terms
of carbon dynamics. The present results also suggest that a single data obtained in Oyashio mixed layer contains 30 μmol/kg of potential uncertainty for the representativity of this region, which leads to a note about a need to treat with
caution results obtained by a single observation in this region. 相似文献
83.
84.
85.
Jung Hae Choi Katsuyuki Kawamura Kazushi Kimoto Yasuaki Ichikawa Byung‐Gon Chae 《国际地质力学数值与分析法杂志》2014,38(16):1744-1760
In porous media, chemical species that dissolve in pore water can be transported via diffusion mechanisms or advective fluxes, close to or far away from where precipitation occurs. In the case of a high‐level radioactive waste disposal system, compacted bentonite is used in a buffer material in an engineering barrier system to minimize the amount of specific nuclides that breach into the surrounding host rock. To minimize breaching, it is very important to understand the transport mechanism of multiple chemical species in porous media. In the following research, we introduced FEM analysis methods using the results of the molecular dynamics simulation and homogenization analysis (MD/HA) method. First, the diffusion coefficients of ions (Cl?, I?, and Na+) in different water layers of Na‐beidellite were calculated using the MD/HA procedure under various dry density (1.2, 1.6, and 2.0 Mg/m3) and temperature (293, 323, and 363 K) conditions. Next, using FEM analysis that used the MD/HA results as input parameters, the diffusion behaviors of ions in porous media were calculated. The results indicate that the diffusion coefficients of the interlayer water in Na‐beidellite are different from the diffusion coefficients under dry density conditions. Further, the concentration profiles (Ct/C0) of iodine and chloride are proportional to temperature but inversely proportional to dry density. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
86.
Hiromi Yamashita 《Ocean & Coastal Management》2009,52(7):327-335
Developments in coastal regions often entail invisible, complex and uncertain aspects of risk. This paper examines: (1) what kinds of environmental risk information are generally “invisible” or difficult to understand; (2) whether or not there is specific “invisible” risk information especially related to coastal development; and (3) what would be bases of risk education in coastal communities in the future. It discusses these by looking at successful and unsuccessful attempts to make some “invisible” risk information visible, using examples from Japan and elsewhere. 相似文献
87.
Aierken Sidike Nuerrula Jilili S. Kobayashi K. Atobe Nobuhiko Yamashita 《Physics and Chemistry of Minerals》2010,37(2):83-89
The photoluminescence (PL) spectra, optical excitation spectra and PL decay curves of anthophyllite from Canada were obtained
at 300 and 10 K. The MnO content in the sample, determined using an electron probe microanalyzer, was high at 5.77 wt%. In
the PL spectra obtained under 410-nm excitation, bright red bands with peaks at 651 and 659 nm were observed at 300 and 10 K,
respectively. The origin of the red luminescence was ascribed to Mn2+ in anthophyllite from the analysis of the excitation spectra and PL decay times of 6.1–6.6 ms. In the PL spectra obtained
under 240-nm excitation at 300 K, a small violet band with a peak at 398 nm was observed. On the violet band at 10 K, a vibronic
structure was observed. The origin of the violet luminescence was attributed to a minor impurity in anthophyllite. 相似文献
88.
Distribution of perfluorinated compounds in surface seawaters between Asia and Antarctica 总被引:3,自引:0,他引:3
Wei S Chen LQ Taniyasu S So MK Murphy MB Yamashita N Yeung LW Lam PK 《Marine pollution bulletin》2007,54(11):1813-1818
89.
Jung Hae Choi A. H. M. Faisal Anwar Katsuyuki Kawamura Yasuaki Ichikawa 《国际地质力学数值与分析法杂志》2009,33(5):687-707
Kaolinite is a common clay mineral. It is a nanomaterial with a platelet crystalline structure. In order to analyze the behavior of kaolinite, its microscopic structure and material properties must be specified correctly. A molecular dynamics (MD) simulation is used for determining the microscale properties of hydrated kaolinite, and these properties are introduced into a multiscale homogenization analysis (HA). We previously developed such an MD/HA technique to investigate seepage, diffusion, sorption and consolidation in bentonite clay (Proceedings of the Science Basis for Nuclear Waste Management, Davos, Switzerland, vol. XXI. Material Research Society: Warrendale, PA, 1997; 359–366; Eng. Geol. 1999; 54 :21–31; Eng. Geol. 2001; 60 :127–138; Coupled Thermo‐Hydro‐Mechanical‐Chemical Processes in Geo‐systems. Elsevier: Amsterdam, 2005; 457–464). We here apply the method to kaolinite clay to investigate the permeability, diffusion and related similitude law. The obtained results are supported by existing experimental data. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
90.
Richard Saunders Rüdiger Kneissl Keith Grainge William F. Grainger Michael E. Jones Alessia Maggi Rhiju Das † Alastair C. Edge Anthony N. Lasenby G. G. Pooley Shigeru J. Miyoshi Taisuke Tsuruta Koujun Yamashita Yuzuru Tawara Akihiro Furuzawa Akihiro Harada Izamu Hatsukade 《Monthly notices of the Royal Astronomical Society》2003,341(3):937-940