Adsorption of Cd<Superscript>2+</Superscript> and Pb<Superscript>2+</Superscript> onto coconut shell biochar and biochar-mixed soil     

G. N. Paranavithana  K. Kawamoto  Y. Inoue  T. Saito  M. Vithanage  C. S. Kalpage  G. B. B. Herath 《Environmental Earth Sciences》2016,75(6):484

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The compressibility of a natural apatite     

K. N.?Matsukagekyoko.nishihara@yale.edu" title="kmatsu@mx.ibaraki.ac.jp  kyoko.nishihara@yale.edu" itemprop="email" data-track="click" data-track-action="Email author" data-track-label="">Email author  S.?Ono  T.?Kawamoto  T.?Kikegawa 《Physics and Chemistry of Minerals》2004,31(9):580-584

In-situ synchrotron X-ray diffraction (XRD) experiments of a natural apatite with the formula of Ca₅(PO₄)₃F_0.94Cl_0.06 were carried out using a diamond anvil cell and angle-dispersive technique at Photon Factory (PF), Japan. Pressure–volume data were collected up to 7.12 GPa at 300 K. The pressures were determined from the ruby fluorescence spectra shift. The unit-cell parameters and volume decreased systematically with increasing pressure, and a reliable isothermal bulk modulus and its pressure derivative were obtained in this study. The third-order Birch–Murnaghan equation of state yielded the isothermal bulk modulus of K_T=91.5(38) GPa, its pressure derivative K_T= 4.0(11), and the zero-pressure volume V₀=524.2(3) ų.  相似文献   

Examining the aerosol indirect effect over China using an SO₂ emission inventory     

Kazuaki Kawamoto  Tadahiro Hayasaka  Teruyuki Nakajima  David Streets  Jung-Hun Woo 《Atmospheric Research》2004,72(1-4):353

The relationship between SO₂ emissions and the effective particle radius of low-level water clouds (r_e) over China was investigated to determine anthropogenic effects on clouds. Sulfur dioxide emission values were obtained from a statistical inventory, and r_e origins were retrieved by satellite remote sensing on a 0.5° grid. Comparisons between annual mean SO₂ emissions and r_e showed generally decreasing r_e values, explained by the Twomey effect. The existence of the Twomey effect is supported by comparisons with simulated aerosol optical depths. Results further suggest that clouds over land show sensitivity to the Twomey effect as well as clouds over the ocean.  相似文献   

Effect of the contraction of Zn-O bonds on X-ray emission spectra     

Kimura  Makoto  Ohashi  Haruo  Osawa  Toshikazu 《Physics and Chemistry of Minerals》1988,15(6):545-547

Physics and Chemistry of Minerals - The X-ray emission spectra were measured for tetrahedrally coordinated Zn ion in several synthetic compounds. Intensity ratios of L β and L α spectral...  相似文献   

Effect of fabric on shear wave velocity in granular soils     

Mital  Utkarsh  Kawamoto  Reid  Andrade  José E. 《Acta Geotechnica》2020,15(5):1189-1203

Acta Geotechnica - The small-strain elastic shear wave velocity ($$V_S$$) is a basic mechanical property of soils and is an important parameter in geotechnical engineering. Recently, $$V_S$$ has...  相似文献   

Analysis of ground surface settlement due to shallow shield tunnels     

T. Kawamoto  K. Okuzono 《国际地质力学数值与分析法杂志》1977,1(3):271-281

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http://www.sciencedirect.com/science/article/pii/S1674987114000681     

Toshikazu Ebisuzaki  Shigenori Maruyama 《地学前缘(英文版)》2015,6(1):103-119

We present the disaster-forced biological evolution model as a general framework that includes Darwinian "phylogenic gradualism",Eldredge-Gould's "punctuated equilibrium",mass extinctions,and allopatric.parapatric,and sympatric speciation.It describes how reproductive isolation of organisms is established through global disasters due to supernova encounters and local disasters due to radioactive volcanic ash fall-outs by continental alkaline volcanism.Our new evolution model uniquely highlights three major factors of disaster-forced speciation:enhanced mutation rate by higher natural radiation level,smaller population size,and shrunken habitat size(i.e.,isolation among the individual populations).We developed a mathematical model describing speciation of a half-isolated group from a parental group,taking into account the population size(N_e),immigration rate(m),and mutation rate(μ).The model gives a quantitative estimate of the speciation,which is consistent with the observations of speciation speed.For example,the speciation takes at least 10~5 generations,if mutation rate is less than10~(-3) per generation per individual.This result is consistent with the previous studies,in which μ is assumed to be 10~(-3)-10~(-5).On the other hand,the speciation is much faster(less than 10~5 generations)for the case that μ is as large as 0.1 in parapatric conditions(m μ).Even a sympatric(m ~ 1) speciation can occur within 10~3 generations,if mutation rate is very high(μ~1 mutation per individual per generation),and if N_e 20-30.Such a high mutation rate is possible during global disasters due to supernova encounters and local disasters due to radioactive ash fall-outs.They raise natural radiation level by a factor of 100-1000.Such rapid speciation events can also contribute to macro-evolution during mass extinction events,such as observed during the Cambrian explosion of biodiversity.A similar rapid speciation(though in a much smaller scale) also has been undergoing in cichlid fishes and great African apes in the last several tens of thousand years in the current African rift valley,including the origin of humankind due to the radioactive ash fall-outs by continental alkaline volcanism.  相似文献   

Mid-latitude horizontal electric fields in the stratosphere during magnetically disturbed periods     

Toshio Ogawa  Hiroto Kawamoto 《Planetary and Space Science》1982,30(10):1013-1024

The horizontal electric field has been measured with balloons over the Pacific Ocean near the Sanriku Coast in Japan. By comparing the electric-field data obtained during magnetically disturbed periods, 16–17 October 1973, 6–7 October 1975 and 3–4 October 1977, with IMF B_z, auroral zone AU and AL, equatorial Dst and $\text{Δ(Dst)}\text{Δt}$, mid-latitude magnetic fields (H, D, Z at Kakioka), and the ionospheric electron density (?₀F2 at Kokubunji), it is found that the observed electric fields of about 9 mVm^?1 made the clockwise rotation during the growth and recovery stages of the magnetospheric substorms. Relations between high and middle latitude ionospheres and between the magnetosphere and the ionosphere are discussed in relation to the origin and propagation of these electric fields.  相似文献   

Single planet formation regime in the high-ionization environment:Possible origin of hot Jupiters and super-Earths     

Yusuke Imaeda  Toshikazu Ebisuzaki 《地学前缘(英文版)》2018,9(4):1023-1031

We studied the particle growth in a protoplanetary disk in a high-ionization environment and found that icy planet formation is inactive for a disk with an ionization rate 100 times higher than that of the present Solar System. In particular, in the case of M 10~(-7.4)M_☉yr~(-1), only rocky planet formation occurs. In such a case, all the solid materials in the disk drift inward, eventually reach the inner MRI front,and accumulate there. They form a dense, thin sub-disk of solid particles, which undergoes gravitational instability to form rocky planetesimals. The planetesimals rapidly grow into a planet through pebble accretion. Consequently, rocky planets tend to be much larger than planets formed through other regimes(tandem planet formation regime and dispersed planet formation regime), in which icy planet formation actively takes place. These rocky planets may evolve into hot Jupiters if they grow fast enough to the critical core mass of the runaway gas accretion before the dispersal of the disk gas, or they may evolve into super-Earths if the gas dispersed sufficiently early.  相似文献   

http://dx.doi.org/10.1016/j.gsf.2016.06.011     

Yusuke Imaeda  Toshikazu Ebisuzaki 《地学前缘(英文版)》2017,8(2):223-231

We present a new united theory of planet formation,which includes magneto-rotational instability(MRl) and porous aggregation of solid particles in a consistent way.We show that the "tandem planet formation" regime is likely to result in solar system-like planetary systems.In the tandem planet formation regime,planetesimals form at two distinct sites:the outer and inner edges of the MRl suppressed region.The former is likely to be the source of the outer gas giants,and the latter is the source for the inner volatile-free rocky planets.Our study spans disks with a various range of accretion rates,and we find that tandem planet formation can occur for M = 10~(7.3)- 10~(-6.9)M_⊙yr~(-1).The rocky planets form between 0.4-2 AU,while the icy planets form between 6-30 All;no planets form in 2—6 AU region for any accretion rate.This is consistent with the gap in the solid component distribution in the solar system,which has only a relatively small Mars and a very small amount of material in the main asteroid belt from 2-6 AU.The tandem regime is consistent with the idea that the Earth was initially formed as a completely volatile-free planet.Water and other volatile elements came later through the accretion of icy material by occasional inward scattering from the outer regions.Reactions between reductive minerals,such as schreibersite(Fe-jP),and water are essential to supply energy and nutrients for primitive life on Earth.  相似文献