Overview of NOPACCS (Northwest Pacific Carbon Cycle Study)     

Hiroyuki Tsubota  Joji Ishizaka  Akira Nishimura  Yutaka W. Watanabe 《Journal of Oceanography》1999,55(6):645-653

The Northwest Pacific Carbon Cycle Study (NOPACCS) was a program aimed at investigating the carbon cycle of the North Pacific Ocean, which can be thought of as a large reservoir of carbon dioxide. NOPACCS was also aimed at estimating the North Pacific's capacity as a carbon sink. Project design, scientific results, and data availability, and subsequent projects resulting from this project are also described in this review. Studies of the upper ocean processes focused on the latitudinal differences in the fugacity of carbon dioxide; and on the detail of plankton community structures. Intermediate water was studied in relation to the formation of North Pacific Intermediate Water and the amount of accumulated anthropogenic carbon. The sedimentation process, past carbon cycle and coral reefs were also studied during the project. A preliminary, overall view of the carbon cycle of the North Pacific was drawn from the results of the project and compared to global values.  相似文献   

Research cooperation forever     

Kojima  Hiroyuki  Serizawa  Minoru 《中国海洋湖沼学报》1998,16(1):4-5

Journal of Oceanology and Limnology -  相似文献   

Trends in pCO2 and sea–air CO2 flux over the global open oceans for the last two decades     

Yosuke Iida  Atsushi Kojima  Yusuke Takatani  Toshiya Nakano  Hiroyuki Sugimoto  Takashi Midorikawa  Masao Ishii 《Journal of Oceanography》2015,71(6):637-661

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Extracellular release of β-lactamase by osmotic shock inSynechococcus transformant     

Yano  Shin-ichi  Kawata  Yoshikazu  Kojima  Hiroyuki 《中国海洋湖沼学报》1998,16(1):105-108

A unicellular cyanobacteriumSynechococcus sp. strain PCC 7002 was transformed with plasmid pQL1, on which β-lactamase gene (bla) and β-galactosidase gene (lacZ) were encoded. The transformant cells released β-lactamase into medium by an abrupt drop of osmotic pressure. This result indicates that this cyanobacterium recognizes and processes the signal sequence of β-lactamase, and accumulates the enzyme in periplasm. Repeated release of β-lactamase was possible by repeated osmotic shocks wihout, impairing cell viability. On the other hand, most of the β-galactosidase remained in cytoplasm under the osmotic shock.

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The fast multipole method for integral equations of seismic scattering problems     

Hiroyuki Fujiwara 《Geophysical Journal International》1998,133(3):773-782

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Effect of nutrient release from sea floor on Si:P ratio in the Buzen-Kai,western Seto Inland Sea,in summer     

Kazuo Abe  Mutsumi Tsujino  Norihisa Nakagawa  Katsuyuki Abo 《Journal of Oceanography》2015,71(2):221-227

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Impacts of nutrient management and decrease in paddy field area on groundwater nitrate concentration: a case study at the Nasunogahara alluvial fan,Tochigi Prefecture,Japan     

Hiroaki Somura  Akira Goto  Hiroyuki Matsui  Elhassan Ali Musa 《水文研究》2008,22(24):4752-4766

In order to help evaluate the trends in the NO₃-N concentration in groundwater with a view to preventing further degradation in water quality in the future, a distributed groundwater quality model was constructed for the Nasunogahara basin. The best fit for the groundwater table elevations by the flow component of the model was achieved with average mean absolute errors (MAEs) of 0·92 m for the calibration period and 0·83 m for the validation period. Moreover, the best fit for the NO₃-N concentration by the water quality component was achieved with average mean relative errors (MREs) of 29·8% for the calibration period and 30·3% for the validation period. After developing a robust model, various change scenarios were tested; specifically, the effects of effluent load control and a decrease in paddy field area on the NO₃-N concentration in groundwater were predicted. The most intensively farmed area contributed about 40% of the total effluent load because of livestock farming in the basin. When the effluent load from this area was decreased by 50%, the average NO₃-N concentrations at sites S1, S2 and S3 were reduced by about 15%; however, the average concentrations at S4 and S5 were reduced by only 1%. Furthermore, when the total effluent load from the concentrated livestock area was removed completely, the average groundwater NO₃-N concentrations at S1, S2 and S3 were reduced by about 30% as compared with the original calculated results. In contrast, decreasing the area of the paddy fields in the basin did not greatly influence the groundwater NO₃-N concentration. In the case of a 70% reduction in paddy field area, average NO₃-N concentrations increased by about 7% at S1, S2 and S3. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

The last deglacial history of Lützow‐Holm Bay,East Antarctica     

Masako Yamane  Yusuke Yokoyama  Hideki Miura  Hideaki Maemoku  Shogo Iwasaki  Hiroyuki Matsuzaki 《第四纪科学杂志》2011,26(1):3-6

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Reaction of forsterite with hydrogen molecules at high pressure and temperature     

Ayako?ShinozakiEmail author  Hisako?Hirai  Hiroyuki?Kagi  Tadashi?Kondo  Taku?Okada  Daisuke?Nishio-Hamane  Shin-ichi?Machida  Tetsuo?Irifune  Takumi?Kikegawa  Takehiko?Yagi 《Physics and Chemistry of Minerals》2012,39(2):123-129

High pressure and temperature reactions of a mixture of forsterite and hydrogen molecules have been carried out using a laser heated diamond anvil cell at 9.8–13.2 GPa and ~1,000 K. In situ X-ray diffraction measurements showed no sign of decomposition or phase transitions of the forsterite under these experimental conditions, indicating that the olivine structure was maintained throughout all runs. However, a substantial expansion of the unit cell volume of the forsterite was observed for samples down to ~3 GPa upon quenching to ambient pressure at room temperature. The Raman spectroscopy measurements under pressure showed significant shifts of the Raman peaks of the Si–O vibration modes for forsterite and of the intramolecular vibration mode for H₂ molecules toward a lower frequency after heating. Additionally, no OH vibration modes were observed by Raman and FT-IR spectroscopic measurements. These lines of evidence show that the observed volume expansion in forsterite is not explained by the incorporation of hydrogen atoms as hydroxyl, but suggest the presence of hydrogen as molecules in the forsterite structure under these high pressure and temperature conditions.  相似文献   

Future changes in tropical cyclone activity in the North Indian Ocean projected by high-resolution MRI-AGCMs     

Hiroyuki Murakami  Masato Sugi  Akio Kitoh 《Climate Dynamics》2013,40(7-8):1949-1968

New and previous versions of the high-resolution 20- and 60-km-mesh Meteorological Research Institute atmospheric general circulation models are used to investigate potential future changes in tropical cyclone (TC) activity in the North Indian Ocean (NIO). Fifteen ensemble experiments are performed under the International Panel on Climate Change A1B scenario. Most of the ensemble future (2075–2099) experiments do not project significant future changes in the basin-scale TC genesis number; however, they commonly show a substantial increase (by 46 %) in TC frequency over the Arabian Sea and a decrease (by 31 %) in the Bay of Bengal. Projected future changes in TC genesis frequency show a marked seasonal variation in the NIO: a significant and robust reduction during the pre-monsoon season, an increase during the peak-monsoon season, and a westward shift during the post-monsoon season. Several large-scale thermodynamic and dynamical parameters are analysed to elucidate the physical mechanism responsible for the future changes in TC activity; this analysis reveals a seasonal dependence of the relative contribution of these parameters to the projected future changes in TC genesis frequency.  相似文献