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11.
Naoki Tanimata Orio Yamamura Yasunori Sakurai Tomonori Azumaya 《Journal of Oceanography》2008,64(2):185-194
The food habits of the dominant myctophid Stenobrachius leucopsarus were examined in the central basin of the Bering Sea in relation to oceanographic conditions, in summer 2002 and 2003 and
spring 2006. S. leucopsarus exhibited an ontogenetic and seasonal dietary shift. In spring, small fish (≤40 mm) preyed mainly on Neocalanus flemingeri/plumchrus whereas large fish fed mainly on Neocalanus cristatus. In summer, small fish preyed mainly on Metridia pacifica whereas large fish fed mainly on euphausiids (Thysanoessa spp.). In the summer of 2003, when water temperature in the epipelagic layer (≤100 m) was warmer, reflecting the prevalence
of the Alaskan Stream, small-sized S. leucopsarus showed a higher stomach content index, perhaps reflecting the greater abundance of M. pacifica. Thus, the present study shows that the physical variability in the epipelagic layer affects not only diets but also feeding
performance of micronekton. 相似文献
12.
Feeding Habits of the Mesopelagic Fish Gonostoma gracile in the Northwestern North Pacific 总被引：1，自引：0，他引：1
The diet of Gonostoma gracile, a numerically abundant mesopelagic fish in the Subtropical Region and the Transition Domain of the northwestern North Pacific,
was examined using 520 specimens collected during June–July 1988, June 1995 and November 1995. The prey included mainly copepods,
ostracods, amphipods and euphausiids. Copepods and ostracods were the most abundant, comprising approximately 70% of the total
diet. There was little evidence of an ontogenetic dietary shift; Pleuromamma copepods were the most abundant prey for all size classes of fish ranging from 19 to 116 mm in standard length. The size
range of prey increased with growth, but all fish sizes examined fed mainly on 1–4 mm long prey. Luminescent copepods and
ostracods were the most abundant prey, suggesting that G. gracile detects its prey visually.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
13.
We investigated the Jurassic Daebo and Cretaceous Bulguksa granitic rocks in South Korea. The former are distributed mainly in the Gyeonggi and Yeongnam massifs and the latter are present in the Gyeongsan basin and Ogcheon belt. The Daebo granitic rocks generally are of ilmenite series and I to S type. These rocks are associated with Au–Ag hydrothermal deposits, whereas the Bulguksa granitic rocks are of magnetite series and I type, and are associated with Pb–Zn, Cu and Mo–W hydrothermal deposits, as well as Au–Ag hydrothermal deposits. The Daebo granitic rocks show adakitic signatures in their chemical compositions. They are considered to have been derived from partial melting of the thick lower continental crust. Conversely, the Bulguksa granitic rocks in the Gyeongsan basin are non‐adakitic and are considered to have been derived from partial melting of a mantle wedge. Magmas of the Daebo granitic rocks formed at relatively shallow levels, but solidified at deep levels compared with those of the Bulguksa granitic rocks. The Bulguksa granitic rocks in the central to western Ogcheon belt are considered to have been formed by fractionation of magmas derived from partial melting of continental crust. The total Al contents of biotite and hornblende in the granitic rocks increased, with the Bulguksa granitic rocks in the Gyeongsan basin < the Bulguksa granitic rocks in the Ogcheon belt and Gyeonggi and Yeongnam massifs and the Daebo granitic rocks in the Ogcheon belt < the Daebo granitic rocks in the Gyeonggi and Yeongnam massifs. This order corresponds to an increase in solidification depth. 相似文献
14.
CFD, system-based and EFD study of ship dynamic instability events: Surf-riding, periodic motion, and broaching 总被引：1，自引：0，他引：1
Hamid Sadat-Hosseini Frederick Stern Naoya Umeda Shinya Yamamura 《Ocean Engineering》2011,38(1):88-110
CFD and system-based simulation are used to predict broaching, surf-riding, and periodic motion for the ONR Tumblehome model, including captive and free model test validation studies. CFD shows close agreement with EFD for calm water resistance, static heel (except for sway force and yaw moment), and static drift (except for roll moment). CFD predictions of static heel in following waves also compare well with EFD except for surge force, sway force, and pitch angle. Froude-Krylov calculations of wave-induced surge force in following waves provides good agreement for high Froude number, but significantly overestimates for Froude number less than 0.2. On the other hand, CFD successfully reproduces the reduction of the wave-induced surge force near Froude number 0.2, probably because CFD can capture the 3D wave pattern. CFD free model simulations are performed for several speeds and headings and validated for the first time for surf-riding, broaching, and periodic motions. System-based simulations are carried out based on inputs from EFD, CFD, and Froude-Krylov for a dense grid of speeds and headings to predict the instability map, which were found to produce fairly similar results. 相似文献
15.
Overall SEDs based on ISO SWS observations show fair agreement with photospheric model predictions for red (super)giant stars.
However, some details of molecular spectra cannot be explained by a photospheric origin. In particular, fine structure in
the H2O 2.7 μm band can be clearly resolved by the SWS and is identified in an early M giant, whose photosphere will never
produce H2O. This is definite evidence for H2O of non-photospheric origin in an early M giant. Also, the observed H2O and
CO2 bands in a late M giant are too strong to be explained by a photospheric origin alone. Further, the H2O 2.7 μm band is
found in four early M supergiants in the h + χ Persei clusters (three of which show UIRs) and is especially strong in the
M4 supergiant S Per (which also shows a highly peculiar SED). Thus, against a belief that H2O is found only in the latest
M giants such as Miras, the SWS has revealed the presence of H2O in a wider region of the HR diagram. The origin of this H2O
is unknown but is probably in a non-photospheric extra envelope. Such a H2O envelope appears to be a general feature through
early M (super)giants to cool supergiants such as S Per, where the envelope has finally developed to be optically thick.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
16.
Relationship Between Solidification Depth of Granitic Rocks and Formation of Hydrothermal Ore Deposits 总被引：14，自引：0，他引：14
Chemical analysis of biotite in representative granitic rocks in Japan shows that the total Al (TAl) content changes with the metal type of the accompanying hydrothermal ore deposits and increases in the following order: Pb‐Zn and Mo deposits < Cu‐Fe and Sn deposits < W deposits < non‐mineralized granitic rocks. The TAl content of biotite in granitic rocks may be a useful indicator for distinguishing between mineralized and non‐mineralized granitic rocks. A good positive correlation is seen between the TAl content of biotite and the solidification pressure of the granitic rocks estimated by sphalerite and hornblende geobarometers and the mineral assemblages of the surrounding rocks. These facts suggest that the TAl content of biotite can be used to estimate the solidification pressure (P) of the granitic rocks. The following empirical equation was obtained: where TAl designates the total Al content in biotite on the basis O = 22. According to the obtained biotite geobarometer, it is estimated that Pb‐Zn and Mo deposits were formed at pressures below 1 kb, Cu‐Fe and Sn deposits at 1–2 kb, W deposits at 2–3 kb and non‐mineralized granitic rocks were solidified at pressures above 3 kb. 相似文献
17.
K. Justtanont J. Cami I. Yamamura T. De Jong L.B.F.M. Waters 《Astrophysics and Space Science》1997,255(1-2):351-357
We have observed ten carbon stars with different mass-loss rates using the Short Wavelength Spectrometer (SWS) on board ISO.
We found that not only the spectral energy distribution and the dust features, but that also that the strength and/or shape
of molecular absorption features in the infrared spectrum varies with the near-infrared color temperature, i.e. with the thickness
of the circumstellar envelope.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
18.
K. Justtanont I. Yamamura T. De Jong L.B.F.M. Waters 《Astrophysics and Space Science》1997,251(1-2):25-30
In this contribution, we present a few highlights of the guaranteed time program to observe AGB stars with differing chemical
compositions and mass loss rates using ISO1 SWS. We briefly discuss C2H2 absorption in C-stars and O-rich stars with the 13 μm dust emission.
This revised version was published online in September 2006 with corrections to the Cover Date. 相似文献
19.
Etsuo Uchida Takuro Haitani Takayuki Suetsugu Takahiro Kashima Ken Tsutsui 《Resource Geology》2003,53(2):155-161
Abstract. The distribution of Na, K, Ca, Mg, Mn and Fe between the granodiorite JG-la, one of the geochemical standard rocks, and 2M NaCl aqueous solution was experimentally determined at temperatures of 300 to 800C and a pressure of 1 kb using standard cold seal-type pressure vessels. The solid run products melted partially at 800C. Only K shows a significantly different behavior from the experiments using the basalt JB-la (Uchida and Tsutsui, 2000) due to the presence of ortho-clase in the JG-la. The transition elements tend to be preferably partitioned into the aqueous chloride solutions with increasing temperature. At 800C and 1 kb, the Fe concentration of the aqueous chloride solutions reached up to 5,000 ppm, and the Mn concentration up to 350 ppm. The distribution coefficient, KD, i = Ci, sol /Ci , rock, is in the order of Na>K>Mn>Ca> Fe>Mg at 300C, but changed in the order of Mn>N>K>Fe>Ca>Mg at 800C. The distribution coefficients of the divalent cations for the JG-la are higher than those for the JB-1a. The distribution coefficient of the transition elements, Fe and Mn, increases significantly with increasing temperature. The thermodynamic analysis for aqueous speciation revealed that this is attributable to the formation of the tri-chloro complexes of the transition elements at higher temperatures. 相似文献
20.
Two practical approaches, response spectrum and time-history methods, are developed to evaluate the response of flexible multi-degree-of-freedom (MDF) systems, notably long-span bridges, to multiple-support seismic excitations. For practical convenience, ground motions within a group of adjacent supports on continuous soil or rock are assumed to be uniform and synchronized, while those of different groups are treated as non-uniform and uncorrelated. The response spectrum analysis is extended to include the cross-correlation of modal responses, which prove important when closely spaced modal frequencies exist. An example of the significance of multiple-support excitations is illustrated by application to a suspension bridge. Qualitatively comparable effects can be expected for other bridges of similar type or dimensions. 相似文献