The spatial and temporal distributions of spheroidal carbonaceous particles from sediment core samples from industrial cities in Japan and China     

Eri Hirakawa  Akiko Murakami-Kitase  Takamoto Okudaira  Jun Inoue  Hideo Yamazaki  Shusaku Yoshikawa 《Environmental Earth Sciences》2011,64(3):833-840

Spheroidal carbonaceous particles (SCPs) are produced by the high-temperature combustion of fossil fuels and emitted in to the atmosphere. The distribution and concentration of SCPs in sediments have been used as a proxy for the distribution of pollutants emitted to the atmosphere. However, the effect on the distribution of SCPs due to industrial activity at nearby industrial cities is yet to be quantified. To clarify the origin of SCPs of ~20 μm in size that are preserved in sediments, we evaluated the abundance, surface morphology, and chemical composition of SCPs in sediment core samples recovered from industrial cities in Japan (Tokyo, Osaka, and Nagasaki) and China (Beijing), with the cities being located at least ~500 km away from each other. Vertical profiles of SCP concentration in sediment cores from the Japanese cities and Beijing are different, reflecting the contrasting industrial histories of the two countries. The SCPs from different cities show contrasting morphological and chemical characteristics, suggesting that ~20 μm SCPs in sediments from the industrial cities could represent the local combustion history in detail, as the influx of local SCPs is dominant at such sites.  相似文献   

Probing primordial magnetic fields with the 21-cm fluctuations     

Hiroyuki Tashiro  Naoshi Sugiyama 《Monthly notices of the Royal Astronomical Society》2006,372(3):1060-1068

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Extinction curves expected in young galaxies     

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   

Strain localization in soft rock—a typical rate‐dependent solid: experimental and numerical studies     

A. R. Bhandari  J. Inoue 《国际地质力学数值与分析法杂志》2005,29(11):1087-1107

Strain localization developing inside soft rock specimens is examined through experimental observation and numerical simulation. In the experimental study, soft rock specimens are sheared at different strain rates under plane strain conditions and deformation and strain localization characteristics are analysed. Transition of localization mode from highly localized mode for higher strain rate to distributed and diffused mode of strain localization for lower strain rates was observed. In the numerical study, simulations of plane strain compression tests are carried out at different strain rates by using an overstressed‐type elasto‐viscoplastic model in finite element computations. The role of strain rates on setting gradients of strain fields across shear band is clarified. The probable mechanism for transition of localization mode is discussed. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

Effects of dust grains on early galaxy evolution     

Hiroyuki Hirashita †  Andrea Ferrara 《Monthly notices of the Royal Astronomical Society》2002,337(3):921-937

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Probing the cosmic reionization history and local environment of gamma-ray bursts through radio dispersion     

Susumu Inoue 《Monthly notices of the Royal Astronomical Society》2004,348(3):999-1008

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The 2000 April multiwavelength campaign of GRS 1915+105     

Y. Ueda  K. Yamaoka  J.E. Grove  M. McCollough  P. Durouchoux  J. Rodriguez  F. Mirabel  J. Swank  M. Feroci  P. Casella  A.J. Castro-Tirado  C. Sánchez-Fernández  S. Chaty  H. Castaneda  K. Kohno  V. Dhawan  S.A. Trushkin  K. Ebisawa  T. Kotani  H. Inoue 《Astrophysics and Space Science》2001,276(1):25-28

We report results from multiwavelength observations of the microquasarGRS 1915+105 performed during the 2000 April campaign. This is one ofthe biggest campaigns ever made for this source covering the broadband from radio to γ-rays. Multiwavelength light curves compiledfrom all the data reduced up to date and broad band spectra obtainedwith ASCA and RXTE are presented.  相似文献   

Determination of oxadiazon residues in the field treated soil with and without organic matter incorporated     

Kassio Ferreira Mendes  Marcelo Rodrigues dos Reis  Ana Beatriz Rocha de Jesus Passos  Miriam Hiroko Inoue  Antônio Alberto Silva  Daniel Valadão Silva 《Environmental Earth Sciences》2016,75(3):222

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Statistical Analysis of Ground Motions Estimated on the Basis of a Recipe for Strong-motion Prediction: Approach to Quantitative Evaluation of Average and Standard Deviation of Ground Motion Distribution     

Masayuki Yamada  Shigeki Senna  Hiroyuki Fujiwara 《Pure and Applied Geophysics》2011,168(1-2):141-153

For seismic hazard assessment, we study the variabilities of predicted ground motion on the basis of a ??recipe for predicting strong ground motion?? and propose approximations to evaluate spatial distributions of the standard deviation for PGV, R1.0, R2.0, and R5.0 in the estimated ground motions. For strong-motion prediction, we use a finite difference method for a long period range (>1.0?s). To estimate variabilities, a Monte Carlo simulation is used and we adopt the Latin Hypercube Sampling (LHS) technique to reduce computations. In this article, we consider only aleatory variabilities in source parameters among all possible variabilities, such as those in the source parameters, the propagation characteristics and site characteristics. Model sources are assumed for dip-slip fault and strike-slip fault, and the variabilities are considered for parameters such as asperity location, rupture starting point, average asperity slip contrast, stress drop and rupture velocity. On the target site, 100 instances of PGV, R1.0, R2.0 and R5.0 data are obtained for 100 sets of parameters and an average and a standard deviation of the log normal distribution, corresponding to the variability for ground motion estimation, are statistically analyzed. For all target sites uniformly distributed in the area around the faults, the average and the standard deviation are statistically analyzed and spread to spatial maps. It is found that the spatial distributions of standard deviation values for both the dip-slip and strike-slip faults are not uniform. Approximations are attempted to develop a quantitative evaluation for spatial distributions of the standard deviation of the log normal distribution for PGV, R1.0, R2.0, and R5.0. The spatial distributions by these approximations are considered to almost reconstruct the characteristics, which are statistically analyzed by the finite difference method.  相似文献   

Rheological contrast between garnet and clinopyroxene in the mantle wedge: An example from Higashi-akaishi peridotite mass,SW Japan     

Masashi Muramoto  Katsuyoshi Michibayashi  Jun-ichi Ando  Hiroyuki Kagi 《Physics of the Earth and Planetary Interiors》2011,184(1-2):14-33

Garnet clinopyroxenites occur within foliated dunite in the Higashi-akaishi peridotite mass, located within the subduction-type high-pressure/low-temperature Sanbagawa metamorphic belt. The garnet clinopyroxenites contain 3–80% garnet, and garnet and clinopyroxene are homogeneously distributed. Garnet crystals contain extensive, regular dislocation arrays and dislocation networks, suggesting that dislocation creep was the dominant deformation mechanism. Analyses of crystallographic orientation maps indicate similar grain sizes and aspect ratios for garnet and clinopyroxene, regardless of modal composition, indicating that these minerals deformed with similar degree of plasticity. Moreover, indexes of crystallographic fabric intensity (i.e., J-index and M-index) for both garnet and clinopyroxene tend to increase with increasing modal composition of garnet. Fourier-transform infrared spectroscopy analysis revealed that water content in garnet is ～60 ppm, whereas that in clinopyroxene is ～70 ppm. Olivine crystal-preferred orientations in the Higashi-akaishi peridotite mass, characterized by [0 0 1] (0 1 0), are thought to have developed during deformation under wet conditions. Consequently, we argue that the presence of water could act to enhance garnet plasticity during deformation. The results reveal contrasting influences of water on the deformation of garnet and diopside: under wet conditions compared with dry, the strain rate increases by two orders of magnitude for garnet but by an order of magnitude for diopside. Given the influence of water on the creep strength of garnet, garnet within the Higashi-akaishi mass may have become significantly as weak as clinopyroxene during deformation.  相似文献