914 research outputs found
Distribution, feeding condition, and growth of Japanese Spanish mackerel (Scomberomorus niphonius) larvae in the Seto Inland Sea
Distribution of eggs and larvae and feeding and growth of
larvae of Japanese Spanish mackerel (Scomberomorus niphonius) were investigated in relation to their prey in the Sea of Hiuchi, the Seto Inland Sea, Japan, in 1995 and 1996. The abundance of S. niphonius eggs and larvae peaked in late May, corresponding with that of clupeid larvae,
the major prey organisms of S. niphonius larvae. The eggs were abundant in the northwestern waters and the larvae were abundant in the southern waters in late May in both years, indicating a southward drift during egg and yolksac stages by residual f low in the central part of the Sea of
Hiuchi. Abundance of clupeid larvae in southern waters, where S. niphonius larvae were abundant, may indicate a spawning strategy on the part of first-feeding S. niphonius larvae to encounter the spatial and temporal peak in ichthyoplankton prey abundance in the Seto Inland Sea.
Abundance of the clupeid larvae was higher in 1995 than in 1996. Feeding incidence (percentage of stomachs with food; 85.3% in 1995 and 67.7% in 1996) and mean growth rate estimated from otolith daily increments (1.05 mm/d in 1995 and 0.85 mm/d in 1996) of S. niphonius larvae in late May were significantly higher in 1995. Young-of-the-year S. niphonius abundance and catch per unit of fishing effort of 1-year-old S. niphonius in the Sea of Hiuchi was higher
in 1995, indicating a more successful recruitment in this year. Spatial and temporal correspondence with high
ichthyoplankton prey concentration was considered one of the important determinants for the feeding success, growth, and survival of S. niphonius larvae
Soliton-induced optical absorption of halogen-bridged mixed-valence binuclear metal complexes
Employing the one-dimensional single-band extended Peierls-Hubbard model, we
investigate optical conductivity for solitonic excitations in halogen-bridged
binuclear metal (MMX) complexes. Photoinduced soliton absorption spectra for
MMX chains possibly split into two bands, forming a striking contrast to those
for conventional mononuclear metal (MX) analogs, due to the broken
electron-hole symmetry combined with relevant Coulomb and/or electron-phonon
interactions.Comment: to be published in Phys. Rev. B 70, No. 7, August 15 (2004
Spin of Stellar-Mass Black Holes Estimated by a Model of Quasi-Periodic Oscillations
We have proposed in previous papers that the high-frequency pair QPOs
observed in black-hole binaries with frequency ratio 3:2 are inertial-acoustic
oscillations (nearly horizontal oscillations with no node in the vertical
direction) or g-mode oscillations, which are resonantly excited on warped
relativistic disks. The resonance occurs through horizontal motions. In this
model the dimensionless spin parameter of the central sources can be
estimated when their masses are known from other observations. This estimate is
done for three sources (GRO J1665-40, XTE J1550-564, GRS 1915+105). For all of
them we have .Comment: 12 pages, 6 figures, PASJ 58 (in press
Optical characterization of platinum-halide ladder compounds
New varieties of quasi-one-dimensional halogen (X)-bridged transition-metal
(M) complexes, (C_8_H_6_N_4_)[Pt(C_2_H_8_N_2_)X]_2_X(ClO_4_)_3_\cdotH_2_O
(X=Br,Cl) and (C_10_H_8_N_2_)[Pt(C_4_H_13_N_3_)Br]_2_Br_4_\cdot2H_2_O,
comprising two-leg ladders of mixed-valent platinum ions, are described in
terms of a multiband extended Peierls-Hubbard Hamiltonian. The polarized
optical conductivity spectra are theoretically reproduced and the ground-state
valence distributions are reasonably determined. The latter variety, whose
interchain valence arrangement is out of phase, is reminiscent of conventional
MX single-chain compounds, while the former variety, whose interchain valence
arrangement is in phase, reveals itself as a novel d-p-\pi-hybridized multiband
ladder material.Comment: 9 pages, 10 figures. to be published in Phys. Rev. B 76, November 15,
No. 1
Effect of high annealing temperature on giant tunnel magnetoresistance ratio of CoFeB/MgO/CoFeB magnetic tunnel junctions
We report tunnel magnetoresistance (TMR) ratios as high as 472% at room
temperature and 804% at 5 K in pseudo-spin valve (SV) CoFeB/MgO/CoFeB magnetic
tunnel junctions (MTJs) annealed at 450oC, which is approaching the
theoretically predicted value. By contrast, the TMR ratios for exchange-biased
(EB) SV MTJs with a MnIr antiferromagnetic layer are found to drop when they
are annealed at 450oC. Energy dispersive X-ray analysis shows that annealing at
450oC induces interdiffusion of Mn and Ru atoms into the MgO barrier and
ferromagnetic layers in EB-SV MTJs. Mechanisms behind the different annealing
behavior are discussed.Comment: 13 pages, 5 figure
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