Reply to Bassin and McKee's comments on “Large suspended particle”     

Masahiro Kajihara  Katsuhiko Matsunaga  Yoshiaki Maita 《Journal of Oceanography》1976,32(2):93-96

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Relationships between trace element concentrations and the stable nitrogen isotope ratio in biota from Suruga Bay,Japan     

Masahiro Sakata  Ai Miwa  Satoshi Mitsunobu  Yasuhiro Senga 《Journal of Oceanography》2015,71(1):141-149

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Spatial variation in organic matter utilization by benthic communities from Yura River–Estuary to offshore of Tango Sea,Japan     

Emily S. Antonio  Akihide Kasai  Masahiro Ueno  Nam-il Won  Yuka Ishihi  Hisashi Yokoyama  Yoh Yamashita 《Estuarine, Coastal and Shelf Science》2010

We investigated the distribution of δ¹³C and δ¹⁵N of organic matter among benthic communities from the upper estuary of Yura River to offshore of Tango Sea, Japan, to determine spatial variation in utilization of organic matter by benthic communities. The δ¹³C values of benthic animals ranged from −27 to −15‰ in the upper estuary, −21 to −15‰ in the lower estuary, −20 to −16‰ in the shallow coast (5–10 m depths), −18 to −16‰ in the deep coast (30–60 m depths) and −19 to −15‰ in offshore (100–150 m depths) stations. Adapting the dual isotope values to mixing models, we estimated the relative contributions of potential food sources to the benthos diet. Phytoplankton and macroalgae that intruded the estuary in summer were utilized as alternative food aside from the terrestrial-origin organic matter assimilated by the estuarine benthic consumers. Resuspended benthic microalgae were important source of energy in the shallow coastal stations, while abundant supply of phytodetritus fueled the deep coastal and offshore benthic food webs. Spatial difference in the diet of benthic communities depends largely on the shifts in the primary carbon source. Thus, benthic communities are important link of autochthonous/allochthonous production and secondary production in the continuous river–estuary–marine system.  相似文献   

Pixel-based and object-based classifications using high- and medium-spatial-resolution imageries in the urban and suburban landscapes     

Ronald C. Estoque  Yuji Murayama  Chiaki Mizutani Akiyama 《国际地球制图》2015,30(10):1113-1129

With the increasing availability of high-spatial-resolution remote sensing imageries and with the observed limitations of pixel-based techniques, the development and testing of geographic object-based image analysis (GEOBIA) techniques for image classification have become one of the main research areas in geospatial science. This paper examines and compares the classification performance of a pixel-based method and an object-based method as applied to high- (QuickBird satellite image) and medium- (Landsat TM image) spatial-resolution imageries in the context of urban and suburban landscapes. For the pixel-based classification, the maximum-likelihood supervised classification approach was employed. And for the object-based classification, the pixel-based classified maps were integrated with a set of image segments produced using various calibrations. The results show evidence that the object-based method can produce classifications that are more accurate for both high- and medium-spatial- resolution imageries in the context of urban and suburban landscapes.  相似文献   

Near-field beam pattern measurement of qualification model of ALMA band 8 (385–500 GHz) cartridge receiver     

Masato Naruse  Tetsuya Ito  Yutaro Sekimoto  Hiroyuki Toba  Naohisa Satou  Masahiro Sugimoto  Wenlei Shan  Yoshizou Iizuka  Toshiaki Kamba  Mamoru Kamikura  Yasutaka Serizawa 《Experimental Astronomy》2009,24(1-3):89-107

We have developed a near-field vector beam measurement system covering the range of frequencies from 385 to 500 GHz. The measurement set-up is capable of measurements with dynamic range exceeding 50 dB and amplitude and phase stability respectively of 0.1 dB/h and 1 degree/5 min at room temperature. Beam patterns of the ALMA band 8 corrugated horns and receiver optics block were measured at room temperature and lately compared with physical optics calculations obtained in the far-field. Both co-polar and cross-polar beam patterns of a qualification model of the ALMA band 8 cartridge cooled in a cartridge-test-cryostat have also been measured in the near-field as a detector of a submillimeter vector network analyzer. The measurements presented in this work refer to the lowest, middle and upper frequencies of band 8. The comparisons between software model and experimental measurements at these frequencies show good agreement down to ?30 dB for the main polarization component. The cross-polarization level of the beam propagating through the receiver optics block was also characterized. We found that a cross-polarization level better than ?28 dB can be achieved at all measured frequencies. The measured beam pattern of this receiver corresponds to efficiency of greater than 92% at the sub reflector (diameter of 750 mm) of the ALMA 12 m optics.  相似文献   

The degree of Cl-loss for the particulate matter (PM) and fog water sampled at the same air mass at the Hachimantai mountain range in northern Japan     

Ryoei Kikuchi  Makoto Takada  Keita Hifumi  Keiji Yoshimura  Toru Ozeki  Takashi Kimoto  Masahiro Kajikawa  Nobuaki Ogawa   《Atmospheric Research》2009,94(3):501-509

It is well known that sea-salt aerosols in particulate matter (PM) react with acids such as H₂SO₄ and HNO₃ during transportation and thereby lose chloride ions (Cl-loss). The PM and fog were sampled concurrently at different altitudes in the Hachimantai mountain range, northern Japan. The PM and fog sampled at different altitudes had nearly identical properties for the ion components. However, the PM was in a Cl-depleted state (more than 80% of all samples), but the fog water was not in so Cl-depleted state (less than 29%). As a result, it could be explained that this phenomenon caused because the fog droplets took up the gaseous state HCl other than sea-salt PM. After all Cl^- in the fog water recovered and was rather rich compared with the sea-salt or the PM by the uptake of the gaseous state HCl. Moreover, it was found that for PM_coarse(2.5 < D < 10), 86% of the acid (H₂SO₄ and HNO₃) was consumed for Cl-loss reactions and/or for dissolution of Ca and Mg in soil particles.  相似文献   

A study of rock alteration process based on kinetics of hydrothermal experiment     

Yoshiro Tsuzuki  Shinjiro Mizutani 《Contributions to Mineralogy and Petrology》1971,30(1):15-33

Experimental investigation was made on hydrothermal alteration of sericite in acid solution. It is found that the sericite is changed to pyrophyllite through kaolinite at 270° C and 260° C, and the alteration is considered to be a consecutive reaction involving two steps, from sericite to kaolinite and from kaolinite to pyrophyllite. On the other hand, pyrophyllite is not formed at 190° C and the sericite is altered to kaolinite. The rate of reaction in each step of this hydrothermal alteration is dependent on reaction temperature and chemical composition of the solution. From the results of the quantitative analyses of the experimental products, kinetic constants and related parameters were obtained.By using these numerical values, an alteration process can be followed in a given model. Computed results for some cases of an alteration of sericite in acid solution are presented. Geological phenomena such as rock alteration or weathering are thought to progress in a disequilibrium state and in an open system. An attempt described in this paper is a physicochemical approach to treat an alteration process accompanied with material transfer occurring in an open system from a kientic viewpoint.  相似文献   

A preliminary stable isotope study of volcanic ashes discharged by the 1979 eruption of Ontake Volcano,Nagano, Japan     

Kusakabe  M.  Mizutani  Y.  Kometani  M. 《Bulletin of Volcanology》1982,45(3):203-209

Sulphur isotopic compositions of pyrite, anhydrite and native sulphur in volcanic ashes discharged by the 1979 eruption of Ontake volcano, Nagano, Japan were determined. The isotopic data indicate that sulphate in anhydrite and a part of native sulphur were produced by the disproportionation reaction of sulphite formed by dissolution of SO₂ in volcanic gases into water which filled a mud reservoir probably located just below the crater zone. Some part of H₂S in volcanic gases was fixed as pyrite and some was oxidised to form native sulphur. Hydrothermal alteration of country rocks to form pyrite, anhydrite and clay minerals had proceeded in the mud reservoir before eruption at temperatures ranging from 110° to 185°C which were estimated by oxygen isotopic fractionation between anhydrite and water.

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Distribution and characteristics of suspended particulate matter in a heavily eutrophic estuary, Tokyo Bay, Japan   总被引：2，自引：0，他引：2  

Suzumura M  Kokubun H  Arata N 《Marine pollution bulletin》2004,49(5-6):496-503

Bulk suspended particulate matter (SPM), chlorophyll a (Chl a), ignition loss, particulate organic carbon (POC), organic nitrogen, inorganic phosphorus (PIP), and organic phosphorus were investigated in the heavily eutrophic Arakawa River estuary, Japan. Chl a was high (approximately 35 microg l(-1)) in summer and low (approximately 6.7 microg l(-1)) in winter and autumn. POC from living phytoplankton accounted for approximately 34% and approximately 70% of total POC during low- and high-biomass seasons, respectively. During the low-biomass season, detrital POC distribution was conservative, and less reactive, land-derived materials mainly composed particulate organic materials (POM), but complex mixing of land-derived POM and autochthonous planktonic detritus caused nonconservative detrital POC behavior during the high-biomass season. PIP concentration in SPM decreased with increasing salinity, likely by desorption of soluble orthophosphate (ortho-P). The ortho-P released from SPM, 56% of the ortho-P input from the Arakawa River to the bay, was a significant potential source of biologically available phosphorus causing eutrophication of coastal environments.  相似文献   

Structure and Evolution of the East Antarctic Lithosphere: Tectonic Implications for the Development and Dispersal of Gondwana   总被引：1，自引：0，他引：1  

Masaki Kanao  Masahiro Ishikawa  Mikiya Yamashita  Katsutada Kaminuma  Larry D. Brown   《Gondwana Research》2004,7(1):31

Lithospheric evolution of the Antarctic shield is one of the keystones for understanding continental growth during the Earth's evolution. Architecture of the East Antarctic craton is characterized by comparison with deep structures of the other Precambrian terrains. In this paper, we review the subsurface structure of the Lower Paleozoic metamorphic complex around the Lützow-Holm area (LHC), East Antarctica, where high-grade metamorphism occurred during the Pan-African orogenic event. LHC is considered to be one of the collision zones in the last stage of the formation of Gondwana. A geoscience program named ‘Structure and Evolution of the East Antarctic Lithosphere (SEAL)’ was carried out since 1996-1997 austral summer season as part of the Japanese Antarctic Research Expedition (JARE). Several geological and geophysical surveys were conducted including a deep seismic refraction/wide-angle reflection survey in the LHC. The main target of the SEAL seismic transect was to obtain lithospheric structure over several geological terrains from the western adjacent Achaean Napier Complex to the eastern Lower Paleozoic Yamato-Belgica Complex. The SEAL program is part of a larger deep seismic profile, LEGENDS (Lithospheric Evolution of Gondwana East iNterdisciplinary Deep Surveys) that will extend across the Pan-African belt in neighboring fragments of Gondwana.  相似文献