Numerical simulation of run-up by variable transformation     

Hiroshi Takeda 《Journal of Oceanography》1984,40(4):271-278

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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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Continuous monitoring of near-bottom mesoplankton communities in the East China Sea during a series of typhoons     

Mary M. Grossmann  Scott M. Gallager  Satoshi Mitarai 《Journal of Oceanography》2015,71(1):115-124

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The　Early　Summer　Seasonal　Change　of　Large－scale　Circulation　over　East　Asia　and　Its　Relation　to　Change　of　The　Frontal　Features　and　Frontal　Rainfall　Environment　During　1991　Summer   总被引：5，自引：0，他引：5  

Gong-Wang Si  Kuranoshin Kato  Takao Takeda 《大气科学进展》1995,12(2):151-176

ＴｈｅＥａｒｌｙＳｕｍｍｅｒＳｅａｓｏｎａｌＣｈａｎｇｅｏｆＬａｒｇｅ－ｓｃａｌｅＣｉｒｃｕｌａｔｉｏｎｏｖｅｒＥａｓｔＡｓｉａａｎｄＩｔｓＲｅｌａｔｉｏｎｔｏＣｈａｎｇｅｏｆＴｈｅＦｒｏｎｔａｌＦｅａｔｕｒｅｓａｎｄＦｒｏｎｔａｌＲａｉｎｆａｌｌＥ...  相似文献   

Garnet-amphibolites at Yokokawa in the Abukuma metamorphic belt,Japan     

Satoshi Kanisawa 《Contributions to Mineralogy and Petrology》1969,20(2):164-176

The mineralogy and petrochemistry of the garnet-amphibolites from the highgrade part of the Abukuma metamorphic belt have been studied, using five analyses of rocks, five of hornblendes, three of garnets and one analysis of cummingtonite, Garnetiferous amphibolites are rich in Fe, whereas non-garnetiferous ones are rich in Mg, especially in cummingtonite-amphibolite. The chemical composition of hornblendes associated with garnet is pargasitic and rich in FeO and poor in CaO, but that of non-garnetiferous rocks is rich in MgO. The garnets are rich in almandine molecule. Mg/Mg + Fe²⁺ ratios of both hornblendes and garnets correspond with those of the host rocks. The development of garnet in the Adirondack metabasites belonging to the upper almandine-amphibolite and granulite facies is observed in Mg-rich rocks as well as in Fe-rich rocks, in which both garnet and hornblende are rich in Mg respectively. However, under the conditions of the andalusite-sillimanite type metamorphism as shown in the Abukuma Plateau, Fe-rich garnet occurs in Fe-rich basic rocks, but cummingtonite occurs in Mg-rich ones instead of Mg-rich garnet. Finally, the problem of polymetamorphism is discussed. The cummingtonite-amphibolite may be the product of polymetamorphism, and Mg-rich garnet which had been present previously was decomposed to cummingtonite and plagioclase by the subsequent regional metamorphism of andalusite-sillimanite type.  相似文献   

Overview of the MITI Nankai Trough Wells: A Milestone in the Evaluation of Methane Hydrate Resources   总被引：4，自引：0，他引：4  

Yoshihiro Tsuji    Hisashi Ishida    Masaru Nakamizu    Ryo Matsumoto  Satoshi Shimizu 《Resource Geology》2004,54(1):3-10

Abstract. Bottom-simulating reflectors suggestive of the presence of methane hydrates are widely distributed below the ocean floor around Japan. In late 1999, drilling of the MITI Nankai Trough wells was conducted to explore this potential methane hydrate resource and a Tertiary conventional structure. The wells are located in the Northwest Pacific Ocean off Central Japan at a water depth of 945 m. A total of six wells were drilled, including the main well, two pilot wells, and three post survey wells at intervals of 10–100 m. All wells except the first confirmed the occurrence of hydrates based on logging-while-drilling, wire-line logging and/or coring using a pressure and temperature coring system in addition to conventional methods. Based on the various well profiles, four methane hydrate-bearing sand-rich intervals in turbidite fan deposits were recognized. Methane hydrates fill the pore spaces in these deposits, reaching saturation of up to 80 % in some layers. The methane hydrate-bearing turbiditic sand layers are less than 1 m thick, with a total thickness of 12–14 m. The bottom depth of high hydrate concentration correlates well with the depth of the bottom-simulating reflector. Based on these exploration results, the Japanese government inaugurated a 16-year methane hydrate exploitation program in 2001.  相似文献   

Nanoscale occurrence of Pb in an Archean zircon   总被引：2，自引：0，他引：2  

Satoshi Utsunomiya  John W. Valley  Simon A. Wilde 《Geochimica et cosmochimica acta》2004,68(22):4679-4686

We report, for the first time, a direct, atomic-scale characterization of Pb in zircon (4.4-3.1 Ga) from the early Archean Yilgarn craton in Australia using high-resolution HAADF-STEM. Two forms of Pb have been identified: Pb concentrated at ∼3 atom% as a nanoscale patch in zircon structure, and Pb concentrated within the amorphous domain created by fission fragment damage. The first result suggests that the Pb atoms directly substitute for Zr⁴⁺ in the zircon structure, and the latter observation demonstrates that Pb diffusion can occur through amorphous regions created by radiation damage, although volume diffusion is typically considered to be the dominant mechanism for Pb diffusion. Beyond the first percolation point, i.e., when the amorphous domains overlap and form a fully interconnected network of amorphous domains, there is a new pathway for the diffusion of Pb that is faster than volume diffusion through crystalline zircon.  相似文献   

Radiolarian Age of Chert-hosted Bedded Manganese Deposits from the Gen-otani Mine in the Tamba District, Northern Kyoto City, Japan     

Satoshi Nakae  Kosei Komuro 《Resource Geology》2005,55(4):311-320

Abstract. Numerous bedded manganese deposits sporadically distributed throughout the Tamba district, southwestern Japan are intercalated within chert sequence. It is well known that radiolarian remains are commonly included in both bedded manganese deposits and host cherts. The Gen‐otani mine, one of these deposits, is located at Otani, Keihoku‐Shimonaka, northern Kyoto City. Chemical composition and age of the chert sequence at the mine were examined. Mainly according to SiO₂ and MnO contents together with lithology, the chert sequence is divided into three sections; lower massive chert, middle bedded manganese deposit and upper bedded chert sections. Radiolarian faunas consisting of middle Jurassic species such as Eucyrtidiellum unumaense, Dictyomitrella(?) kamoensis, Parvicingula dhimenaensis, Sethocapsa aitai, Sethocapsa kodrai, Transhsuum brevicostatum, Tricolocapsa plicarum, Unuma echinatus and others were extracted from both the middle manganese section and overlying bedded chert of the upper section. This examination reveals that the bedded manganese deposit at the Gen‐otani mine formed until Bajocian to early Bathonian (middle Middle Jurassic) in age.  相似文献   

Rheological and kinematical responses to flow of two-phase rocks     

Yoshi-Taka Takeda  Albert Griera 《Tectonophysics》2006,427(1-4):95

Numerical simulations have been performed to investigate the strain-dependent behaviour of rheological and kinematical responses to flow of two-phase rocks using the commercial finite-difference program FLAC2D. It was assumed that the two phases have Maxwell rheology. Plane strain and velocity boundary condition, which produces a simple shear deformation, were also assumed. Two types of geometries were considered: strong phase supported (SPS) and weak phase supported (WPS). We calculated strain-dependent variations of effective viscosity and partitioning of strain rate, vorticity and kinematic vorticity number during deformation in both SPS and WPS structure models.The results show that the strain-dependent behaviour is largely influenced by the geometry of the composite. SPS models show both strain hardening and strain softening during the simulations, with strain hardening preceding strain softening. A critical shear strain is necessary to begin the strain softening behaviour. Strain hardening and strain softening are accompanied by a reduction and an increase of the partition of strain rate into the weak phase, respectively. On the other hand, WPS models show only weak strain hardening and strain softening, being the strain-dependent behaviour close to a steady state flow. In addition, the following results are obtained on vorticity and kinematic vorticity number; (1) in both SPS and WPS models the partition of vorticity into weak phase increases with progressive shear strain, i.e. the strong phase becomes less rotational, (2) in SPS models weak inclusions changes from sub-simple shear to super-simple shear with progressive strain, whereas the strong matrix changes from super-simple shear to sub-simple shear, (3) in WPS models the strong inclusions with high viscosity contrasts are less rotational but can be in super-simple shear condition to high strains.The observed strain-dependent behaviours have been compared with previous proposed analytical models. The degree of agreement is variable. Balshin and Ryshkewitch–Duckworth models are only applicable to SPS models. Ji-generalized mixture rule model is applicable to both models.The results suggest that polyphase rocks with SPS structure during ductile shear deformation respond as strain softening materials, after an initial strain hardening stage that may drive to the strain localization into the material.  相似文献   

High-Speed Data Acquisition System Messia for Subaru     

Maki Sekiguchi  Hidehiko Nakaya  Hirokazu Kataza  Satoshi Miyazaki 《Experimental Astronomy》1998,8(1):51-58

We have developed a high-speed data acquisition system, Messia-III (Modularized Extensible SyStem for Image Acquisition) for Subaru, Japanese 8.2m telescope. Messia has a direct 1-Gbps link to a host UNIX workstation. Messia is a VMEbus-based system but it does not have local OS nor CPU's in order to minimize software development and maintenance.  相似文献