Holographic View of Cosmological Perturbations     

Jiro Soda  Sugumi Kanno 《Astrophysics and Space Science》2003,283(4):639-644

The cosmological perturbation theory is revisited from the holographic point of view. In the case of the single brane model, it turns out that the AdS/CFT correspondence plays an important role. In the case of the two-brane model, it is shown that the effective equations of motion becomes the quasi-scalar-tensor gravity. It is also demonstrated that the radion anisotropy gives the CMB fluctuations through the Sachs-Wolfe effect. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Emission curve of growth for Feii in chromospheric limb spectra     

Y. Hanaoka  I. Tsuda  K. Sadakane  M. Kanno 《Solar physics》1986,106(1):87-93

The 270 chromospheric emission lines of Feii ranging between 2000 and 3200 Å observed by Skylab at a height of 4 (2900 km) above the limb of the quiet Sun are analyzed by the emission curve of growth method, using newly calculated gf-values. It is derived that the excitation temperature is 7.2 × 10³ K and that the turbulent velocity is consistent with the previous results that the microturbulent velocity is lower than 10 km s^–1 in the cool (<10⁴ K) region of the chromosphere.Contributions from the Kwasan and Hida Observatories, University of Kyoto, No. 270.  相似文献   

Life habit of vesicomyid clam,Calyptogena soyoae,and hydrogen sulfide concentration in interstitial waters in Sagami Bay,Japan     

Jun Hashimoto  Suguru Ohta  Katsunori Fujikura  Yoshihiro Fujiwara  Shunji Sukizaki 《Journal of Oceanography》1995,51(3):341-350

In and around the beds of vesicomyid clam (Calytogena soyoae) located off Hatsushima Island in Sagami Bay, central Japan, hydrogen sulfide concentration in bottom water and interstitial water was measured every 10 cm from just above seafloor to 40 cm deep usingin situ separative dialysis bags. While hydrogen sulfide over 0.01 mmol/kg was not measured from the seawater just above the dense clam beds, the concentration of hydrogen sulfide increased rapidly below 10 cm deep. The results indicate that the habit of the clam is correlated with high concentration of hydrogen sulfide contained in pore waters of sediments between depths of 10 and 20 cm from the bottom surface. Concentrations of hydrogen sulfide ranging from approximately 0.05 mmol/kg to 0.6 mmol/kg might be suitable requirement for the habitat ofC. soyoae.  相似文献   

Numerical study of enhanced energy dissipation near a seamount     

Nobuyuki Iwamae  Toshiyuki Hibiya  Yoshihiro Niwa 《Journal of Oceanography》2006,62(6):851-858

Using a two-dimensional primitive equation model, we examine nonlinear responses of a semidiurnal tidal flow impinging on a seamount with a background Garrett-Munk-like (GM-like) internal wavefield. It is found that horizontally elongated pancake-like structures of high vertical wavenumber near-inertial current shear are created both in the near-field (the region over the slope of the seamount) and far-field (the region over the flat bottom of the ocean). An important distinction is that the high vertical wavenumber near-inertial current shear is amplified only at mid-latitudes in the far-field (owing to a parametric subharmonic instability (PSI)), whereas it is amplified both at mid-and high-latitudes (above the latitude where PSI can occur) in the near-field. In order to clarify the generating mechanism for the strong shear in the near-field, additional numerical experiments are carried out with the GM-like background internal waves removed. The experiments show that the strong shear is also created, indicating that it is not caused by the interaction between the background GM-like internal waves and the semidiurnal internal tides. One possible explanation is proposed for the amplification of high vertical wavenumber near-inertial current shear in the near-field where tide residual flow resulting from tide-topography interaction plays an important role in transferring energy from high-mode internal tides to near-inertial internal waves.  相似文献   

Japan-equator XBT sections in late November 1989 and in early December 1991     

Jiro Yoshida  Hideo Sudo  Masaji Matsuyama  Yoshihiro Kurita  Yuji Mine 《Journal of Oceanography》1993,49(1):121-129

A comparison between Japan-equator XBT sections along 150°E in late November 1989 and along 140°E in early December 1991 is made. The warmest surface water above 29°C diminished to the south of 2–4°N and the surface mixed layer noticeably decreased in thickness in the equatorial region in December 1991; besides, the North Equatorial Countercurrent was intensified. This is considered to be a manifestation of changes in the surface layer of the western equatorial Pacific in the mature phase of El Niño.  相似文献   

Water exchange and material exchange through a strait due to tidal flow     

Yoshihiro Mazda 《Journal of Oceanography》1984,40(1):19-28

The process of material transport through a strait due to tidal flow is modeled, and then the differences between various concepts of tidal exchange which have been used hitherto are pointed out using this model. In particular, the exchange of water itself and the exchange of material should be distinguished even in the case where the material of interest is carried by the water,i.e., the material and water move as one body. Further, the physical meaning of “tidal trapping” (Fischeret al., 1979) is discussed by using the model in this paper. The relationship between the exchange ratio for the water itself (r) and the phase lag (δ) of material concentration to the tidal stream in a section of the strait, which is an important factor in tidal trapping, is obtained as follows: $$\delta = \tan ^{ - 1} \left( {\tfrac{1}{r} - 1} \right)$$ Observational results at Lake Hamana (Shizuoka Pref) and at Kabira Cove (Okinawa Pref.) support the validity of the above relationship.  相似文献   

Moisture movement under a temperature gradient in highly compacted bentonite     

T. Kanno  K. Kato  J. Yamagata 《Engineering Geology》1996,41(1-4):287-300

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Impact of the winter North Atlantic Oscillation (NAO) on the Western Pacific (WP) pattern in the following winter through Arctic sea ice and ENSO. Part II: multi-model evaluation of the NAO–ENSO linkage     

Tetsu Nakamura  Masayuki Hara  Miki Oshika  Yoshihiro Tachibana 《Climate Dynamics》2015,45(11-12):3547-3562

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Sorption behavior of the Pt(II) complex anion on manganese dioxide (δ-MnO2): a model reaction to elucidate the mechanism by which Pt is concentrated into a marine ferromanganese crust     

Mamiko Yamashita Maeno  Hironori Ohashi  Kotaro Yonezu  Akane Miyazaki  Yoshihiro Okaue  Koichiro Watanabe  Tamao Ishida  Makoto Tokunaga  Takushi Yokoyama 《Mineralium Deposita》2016,51(2):211-218

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The use of microstructures for discriminating turbiditic and hemipelagic muds and mudstones          下载免费PDF全文

Yoshihiro Kase  Makoto Ito  Ken Ikehara  Shigeru Takizawa 《Sedimentology》2016,63(7):2066-2086

The microstructures of turbiditic and hemipelagic muds and mudstones were investigated using a scanning electron microscope to determine whether there are microstructural features that can differentiate turbiditic from hemipelagic sedimentary processes. Both types of muddy deposits are, in general, characterized by randomly‐oriented clay particles. However, turbiditic muds and mudstones also characteristically contain aggregates of ‘edge‐to‐face’ contacts between clay particles with long‐axis lengths of up to 30 μm. Based on observations of the clay fabric of the experimentally‐formed muds settled from previously agitated muddy fluids, these types of aggregates, hereafter referred to as ‘aggregates of clay particles’, are interpreted as having been formed by the collision of component flocs in turbulent fluids. Furthermore, some aggregates of clay particles have ‘face‐to‐face’ contacts between clay particles; this is similar to face‐to‐face aggregates characteristically developed in fluid‐mud deposits that are commonly recognized only in turbiditic mudstones, indicating the possibility of a final stage of deposition under highly‐dense conditions, such as temporary fluid muds. In conjunction with earlier proposed lithofacies‐based and ichnofacies‐based criteria, aggregates of clay particles should be useful for the differentiation of turbiditic and hemipelagic muddy deposits, particularly with limited volumes of non‐oriented samples from deep‐water successions.  相似文献