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81.
Tsutomu Ikeda 《Journal of Oceanography》2011,67(6):785-790
This study demonstrates reduced electron transfer system (ETS) activity of mixed copepods collected from 5,000 to 7,000 m
depths [3.21 ± 1.25 μl O2 (mg protein)−1 h−1 at 10°C] as compared with mixed copepods from 0 to 200 m depths [5.93 ± 1.66 μl O2 (mg protein)−1 h−1 at 10°C] of the western subarctic Pacific. At the in situ temperature of 1.5°C, the 5,000–7,000 m ETS data, in terms of wet
mass (WM)-specific respiration rates (R), is equivalent to [0.052 ± 0.021 μl O2 (mg WM)−1 h−1] which is similar to or greater than those reported for selected copepods or mixed mesozooplankton from <5,000 m depth by
previous workers. 相似文献
82.
Hiroyuki Hirashita Takaya Nozawa Tsutomu T. Takeuchi Takashi Kozasa 《Monthly notices of the Royal Astronomical Society》2008,384(4):1725-1732
We investigate the extinction curves of young galaxies in which dust is supplied from Type II supernovae (SNe II) and/or pair instability supernovae (PISNe). Since at high redshift ( z > 5), low-mass stars cannot be dominant sources for dust grains, SNe II and PISNe, whose progenitors are massive stars with short lifetimes, should govern the dust production. Here, we theoretically investigate the extinction curves of dust produced by SNe II and PISNe, taking into account reverse shock destruction induced by collision with ambient interstellar medium. We find that the extinction curve is sensitive to the ambient gas density around a SN, since the efficiency of reverse shock destruction strongly depends on it. The destruction is particularly efficient for small-sized grains, leading to a flat extinction curve in the optical and ultraviolet wavelengths. Such a large ambient density as n H ≳ 1 cm−3 produces too flat an extinction curve to be consistent with the observed extinction curve for SDSS J1048+4637 at z = 6.2. Although the extinction curve is highly sensitive to the ambient density, the hypothesis that the dust is predominantly formed by SNe at z ∼ 6 is still allowed by the current observational constraints. For further quantification, the ambient density should be obtained by some other methods. Finally, we also discuss the importance of our results for observations of high- z galaxies, stressing a possibility of flat extinction curves. 相似文献
83.
An eddy covariance system using a closed-path CO2analyser was constructed for long-term CO2flux measurements above a forest, and its total frequency response was valuated experimentally. The amplitude and phase responses of the system wereexamined through a preliminary test, in which a prescribed pattern of CO2fluctuation was input to the system. The result showed that the amplitude of the output from the system was attenuated as frequency increased, with a half-power frequency of 0.3 Hz. The phase was delayed by the air sampling through a long tube, but the delay in phase decreased asfrequency increased. We then presented a new technique for the correction of flux loss due to the inadequate system response for the eddy covariance measurements of CO2 flux. Using the present system and the correction technique, diurnal variations in CO2 flux were measured over a temperate deciduous forest on three days in 1997. The results were compared with the CO2fluxes measured with a fast response open-path gas analyser. The CO2fluxes from the closed-path system agreed with those from the open-path system after the Webb, Pearman and Leuning correction was made for the latter. In the present test over a forest, the contribution of the frequency-response correction to the CO2fluxes was small and its averaged percentage was only 3%in the daytime. However, the percentage would likely increase, if the system were applied to a shorter vegetation site where high frequency components are more important. The comparison confirmed that we can obtain correct measurements of CO2flux using the present closed-path system and the correction technique. 相似文献
84.
Hiroyuki Hirashita †‡ Takaya Nozawa Takashi Kozasa Takako T. Ishii † Tsutomu T. Takeuchi § 《Monthly notices of the Royal Astronomical Society》2005,357(3):1077-1087
We investigate the extinction curves of young galaxies in which dust is supplied from Type II supernovae (SNe II) and/or pair instability supernovae (PISNe). We adopt Nozawa et al. (2003) for compositions and size distribution of grains formed in SNe II and PISNe. We find that the extinction curve is quite sensitive to internal metal mixing in supernovae (SNe). The extinction curves predicted from the mixed SNe are dominated by SiO2 and are characterized by a steep rise from infrared to ultraviolet (UV). The dust from unmixed SNe shows a shallower extinction curve, because of the contribution from large-sized (∼0.1 μm) Si grains. However, the progenitor mass is important in unmixed SNe II: if the progenitor mass is smaller than ∼20 M⊙ , the extinction curve is flat in UV; otherwise, the extinction curve rises towards the short wavelength. The extinction curve observed in a high-redshift quasar ( z = 6.2) favours the dust production by unmixed SNe II. We also provide some useful observational quantities, so that our model might be compared with future high- z extinction curves. 相似文献
85.
A new method for simulation of atmospheric effect on the emergent radiation over non-uniform terrain
For a precise atmospheric correction over the non-uniform terrain in satellite imageries, a numerical method for evaluating the upwelling radiation at the top of the atmosphere bounded by the non-uniform surface is developed as an extended doubling-adding method. The present method enable us to treat quantitatively the case of hazy atmosphere and (or) large albedo of the surface. 相似文献
86.
Yuji Watanabe Atsushi Yamaguchi Hiroshi Ishida Takashi Harimoto Shinya Suzuki Yoshio Sekido Tsutomu Ikeda Yoshihisa Shirayama Masayuki Mac Takahashi Takashi Ohsumi Joji Ishizaka 《Journal of Oceanography》2006,62(2):185-196
The first CO2 exposure experiments on several species of pelagic copepods inhabiting surface and deep layers in the western North Pacific
were conducted. Living organisms were collected from two layers between the surface and 1,500 m between latitudes of 11 and
44°N, and they were exposed aboard ship to various pCO2 up to about 98,000 μatm. Mortality of copepods from both shallow and deep layers in subarctic to subtropical regions increased with increasing
pCO2 and exposure time. Deep-living copepods showed higher tolerance to pCO2 than shallow-living copepods. Furthermore, deep-living copepods from subarctic and transitional regions had higher tolerances
than the subtropical copepods. The higher tolerances of the deep-living copepods from subarctic and transitional regions may
be due to the adaptation to the natural pCO2 conditions in the subarctic ocean. 相似文献
87.
Tsutomu Takashima 《Astrophysics and Space Science》1975,36(2):319-328
The procedure of computing the intensity and the polarization parameters of radiation diffusely reflected and transmitted by an inhomogeneous, plane-parallel planetary atmosphere is discussed with the aid of the adding method. If the atmosphere is simulated by a number of homogeneous sublayers (aerosols and ozone may be included), the matrices of radiation diffusely reflected and transmitted by the atmosphere can be expressed in terms of these matrices of sublayers by using only a couple of iterative equations with the polarity effect of radiation. This procedure is to be extended to the model atmosphere bounded by the surface reflector with a quite arbitrary phase matrix. 相似文献
88.
Tsutomu Saito 《Journal of Geodesy》1970,44(4):341-373
In this paper the author shows a procedure to settle the computation of very long geodesic lines on the ellipsoid without
using the series expansion. The integration of elliptic integrals appearing in the procedure is numerically carried out by
means of a mechanical quadrature-the method of Repeated Interval Halving.
The author also devises formulae for the numerical solution of the problem, in order to make the amount of significance error
least and determine the kind of quadrant for the computation of inverse trigonometric function.
The anti-podal problem for the direct and inverse solution is rigorously solved by this method. 相似文献
89.
Tsutomu Saito 《Journal of Geodesy》1979,53(2):165-177
Formulas for computing geodesics on the bi-axial ellipsoid through Gaussian quadrature are shown; the estimation of computational
errors, truncation and roundoff errors, for the quadrature is carried out; and test examples found in [3] together with those
which consist of near anti-podal points on the neighborhood of the equator, are computed with the evaluation of the computational
errors. 相似文献
90.