343 pp., Hardcover, US$ 143.00/Dfl. 250.00E. Juhàcovà, Seismic Effects on Structures, Elsevier (1991).     

Tsuyoshi Ishida 《Engineering Geology》1992,32(4):286-287

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Application of the Distinct Element Method for analysis of toppling observed on a fissured rock slope   总被引：1，自引：0，他引：1  

T. Ishida  M. Chigira  S. Hibino 《Rock Mechanics and Rock Engineering》1987,20(4):277-283

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Agricultural typology and land use: Reeds, L.G., ed. (1973): proceedings of the agricultural typology commission meeting, McMaster University, Hamilton, Ont., 1972. 350 pp., tables, maps and diagrams. $12.00     

H. Ishida 《Geoforum》1975,6(3-4)

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Size and taxonomic plankton community structure and carbon flow at the equator, 175‡E during 1990–1994     

J. Ishizaka  K. Harada  K. Ishikawa  H. Kiyosawa  H. Furusawa  Y. Watanabe  H. Ishida  K. Suzuki  N. Handa  M. Takahashi 《Deep Sea Research Part II: Topical Studies in Oceanography》1997,44(9-10)

Size and taxonomic structure of plankton community carbon biomass for the 0.2–2000 μm equivalent spherical diameter range were determined at the equator at 175°E in September 1990–1993 and April 1994. Total biomass of the plankton community ranged from 1944 to 3448 mg C m⁻². Phytoplankton, zooplankton and bacteria carbon biomasses were 604–1669 mg C m^-2, 300–797 mg C m², and 968–1200 mg C m^-2, and the percentages were 31–54%, 15–26%, and 29–54%, respectively. Biomass of heterotrophic bacteria was always the largest fraction andProchlorococcus biomass was second. Heterotrophic and autotrophic flagellates and dinoflagellates in the nanoplankton size range and copepods (adults and copepodites) in the mesoplankton range were also high. Relatively small biomass was observed in the microplankton size range. The differences in integrated biomass of plankton community for El Nin˜o type oligotrophic conditions of September 1990–1993 and non-El Nifio type mesotrophic conditions of April 1994 were generally small compared with the interannual difference during 1990–1993. However, the percentage ofProchlorococcus in phytoplankton carbon biomass was larger in non-El Nin˜o year. Biomasses of cyanobacteria, diatom, dinoflagellates, nauplii of copepods, and crustaceans other than copepods were larger in the non-El Nin˜o year. Primary production increased significantly from El Nin˜o to non-El Nin˜o years. Carbon flow through the plankton food chain was estimated using the plankton carbon biomass data, primary production measurements, and published empirical relationships.  相似文献   

Meridional distribution and carbon biomass of autotrophic picoplankton in the Central North Pacific Ocean during late northern summer 1990     

Joji Ishizaka  Hiroshi Kiyosawa  Kazunori Ishida  Kimitoshi Ishikawa  Masayuki Takahashi 《Deep Sea Research Part I: Oceanographic Research Papers》1994,41(11-12)

The meridional distribution of autotrophic picoplankton groups in the central north Pacific was studied during the late northern summer of 1990. Sampling was along a section at 175°N which extended from 45°N to 8°S. The section is far from coastal regions and included subarctic, central gyre, and equatorial areas. Five autotrophic picoplankton groups, autotrophic microflagellate, red-fluorescing picoplankton,Synechococcus, prochlorophyte, and orange-fluorescing picoplankton, were identified from samples taken at stations distributed along this section. These five groups showed distinctive differences in their meridional and vertical distributions. The autotrophic microflagellates and red-fluorescing picoplankton showed distributions that were similar to that of chlorophyll a, which was dominated by the <3 μm size fraction. However, the vertical distribution of these groups was different.Synechococcus was found mostly in surface waters (PAR<10%) and was particularly abundant in the Kuroshio Extension and south of the equatorial region where the nitracline was shallow (50–75 m). Prochlorophytes were abundant in the deep euphotic layer (PAR 1-0.1%) from the south of the Kuroshio Extension to the south of the equatorial area. Orange-fluorescing picoplankton, which may be one kind of cyanobacteria but is larger than typical Synechococcus, were mostly distributed in the oligotrophic surface waters of the central gyre. The carbon biomass estimates for these organisms showed that these five groups dominated in different areas. The vertical distribution of carbon biomass did not correspond to that of chlorophyll a in the central gyre and south of the equator because of the larger carbon/ chlorophyll a ratio of Synechococcus and orange-fluorescing picoplankton relative to that of the other picoplankton.  相似文献   

SIMS Bias on Isotope Ratios in Ca‐Mg‐Fe Carbonates (Part III): δ18O and δ13C Matrix Effects Along the Magnesite–Siderite Solid‐Solution Series          下载免费PDF全文

Maciej G. Śliwiński  Kouki Kitajima  Michael J. Spicuzza  Ian J. Orland  Akizumi Ishida  John H. Fournelle  John W. Valley 《Geostandards and Geoanalytical Research》2018,42(1):49-76

This study explores the effects of cation composition on mass bias (i.e., the matrix effect), which is a major component of instrumental mass fractionation (IMF) in the microanalyses of δ¹³C and δ¹⁸O by SIMS in carbonates of the magnesite–siderite solid‐solution series (MgCO₃–FeCO₃). A suite of twelve calibration reference materials (RMs) was developed and documented (calibrated range: Fe# = 0.002–0.997, where Fe# = molar Fe/[Mg + Fe]), along with empirical expressions for regressing calibration data (affording residuals < 0.5‰ relative to certified reference material NIST‐19). The calibration curves of both isotope systems are non‐linear and have, over a 2‐year period, fallen into one of two distinct but largely self‐consistent shape categories (data from ten measurement sessions), despite adherence to well‐established analytical protocols for carbonate δ¹³C and δ¹⁸O analyses at WiscSIMS (CAMECA IMS 1280). Mass bias was consistently most sensitive to changes in composition near the magnesite end‐member (Fe# 0–0.2), deviating by up to 4.5‰ (δ¹³C) and 14‰ (δ¹⁸O) with increasing Fe content. The cause of variability in calibration curve shapes is not well understood at present and demonstrates the importance of having available a sufficient number of well‐characterised RMs so that potential complexities of curvature can be adequately delineated and accounted for on a session‐by‐session basis.  相似文献   

Effects of cyclonic mesoscale eddies on the marine ecosystem in the Kuroshio Extension region using an eddy-resolving coupled physical-biological model   总被引：2，自引：0，他引：2  

Yoshikazu Sasai  Kelvin J. Richards  Akio Ishida  Hideharu Sasaki 《Ocean Dynamics》2010,60(3):693-704

Effects of mesoscale eddies on the marine ecosystem in the Kuroshio Extension (KE) region are investigated using an eddy-resolving coupled physical-biological model. The model captures the seasonal and intra-seasonal variability of chlorophyll distribution associated with the mesoscale eddies, front variability, Kuroshio meanders, and upwelling. The model also reproduces the observed interannual variability of sea surface height anomaly (SSHA) in the KE region along a zonal band of 32–34°N from 2002 to 2006. The distribution of high surface chlorophyll corresponds to low SSHA. Cyclonic eddies are found to detach from the KE jet near 150°E and 158°E and propagate westward. The westward propagating cyclonic eddies lift the nutrient-rich thermocline into the euphotic zone and maintain high levels of chlorophyll in summer. In the subsurface layer, the pattern in chlorophyll is influenced by both lateral and vertical advection. In winter, convection inside the eddy entrains high levels of nutrients into the mixed layer, increasing production, and resulting in high chlorophyll concentration throughout the surface mixed layer. There is significant interannual variability in both the cyclonic eddy activity and the surface phytoplankton bloom south of the KE jet, although whether or not there is a causal link is unclear.  相似文献   

Spatio-temporal streamflow generation in a small,steep headwater catchment in western Japan     

Haotian Sun  Tamao Kasahara  Kyoichi Otsuki  Takami Saito  Yuichi Onda 《水文科学杂志》2017,62(5):818-829

Headwaters contribute a substantial part of the flow in river networks. However, spatial variations of streamflow generation processes in steep headwaters have not been well studied. In this study, we examined the spatio-temporal variation of streamflow generation processes in a steep 2.98-ha headwater catchment. The time when baseflow of the upstream section exceeded that downstream was coincident with the time when the riparian groundwater switched from downwelling to upwelling. This suggests that upwelling of the riparian groundwater increased considerably in the upstream section during the wet period, producing a shift in the relative size of baseflow between the upstream and downstream sections. The timing of fluctuations among hillslope soil moisture, hillslope groundwater and streamflow reveals that the hillslope contributed to storm flow, but this contribution was limited to the wet period. Overall, these results suggest that streamflow generation has strong spatial variations, even in small, steep headwater catchments.