Evidence of earth catastrophe by anomalous shocked quartz at the K/T boundary     

YASUNORI MIURA  Toshio KATO  Masashi Imai 《Celestial Mechanics and Dynamical Astronomy》1992,54(1-3):249-253

Anomalous shocked quartz with high density (less than 1 % of density-deviation) is considered to be a relict of ultra high-pressure at meteoritic impact. The shocked quartz grains can be found only in terrestrial and artificial impact craters, meteorites and the Cretaceous-Tertiary (K/T) boundary samples. Volcanic activity is considered to be started or accelerated by enormous impact event.  相似文献   

Measurement of the absolute intensity of cosmic X-rays     

M. Matsuoka  M. Oda  Y. Ogawara  S. Hayakawa  T. Kato 《Astrophysics and Space Science》1969,4(1):44-63

The intensity of the diffuse component of cosmic X-rays was measured with use of a rotating collimator system borne on a sounding rocket. A part of background counts proportional to the field of view of proportional counters enabled us to determine the intensity of the diffuse component to be 0.66±0.07 photons cm^–2 sec^–1 keV^–1 in the energy range between 3.6 and 9.0 keV. The spectrum in this energy range was found to be comparatively flat. The intensity of Sco X-1 was also measured and its time variation was investigated.  相似文献   

Schumann resonance observation in China and anomalous disturbance possibly associated with Tohoku M9.0 earthquake     

Xinyang Ouyang  Xuemin Zhang  A. P. Nickolaenko  M. Hayakawa  Xuhui Shen  Yuanqing Miao 《地震科学（英文版）》2013,26(2):137-145

Schumann resonance (SR) is an electromagnetic resonance phenomenon in the Earth–ionosphere cavity exited by global lightning activities when the wavelength matches the circumference of the Earth, and the lowest four peak frequencies of SR are about 8, 14, 20, and 26 Hz. This article presents the new observational data of SR in China. The observations of two horizontal magnetic components (B _NS and B _EW) in the frequency band range of 3–29 Hz at Yongsheng observatory (26.7°N, 100.8°E) in southwestern China were mainly analyzed. It is found that the SR amplitudes at peak frequencies in B _NS and B _EW components all showed diurnal and seasonal variations, and that the SR amplitude in B _NS component is always higher than that in B _EW component. Diurnal variation of SR amplitude around equinoxes and solstices in B _NS component is related to active intervals of three global thunderstorm centers, while SR amplitude in B _EW component is the most significant at around 16 LT, corresponding to Asian center. SR amplitudes both in B _NS and B _EW components increase in the rainy season from May to September. In addition, the SR anomalies in association with the 2011 Japan earthquake are exhibited. The anomalous effect was characterized by an increase in amplitude at the lowest four SR modes beginning at 4 days before this earthquake. Upon analyzing the wave interference between the direct wave and disturbed wave scattered by localized modification of lower ionosphere over the epicenter, Asian and African thunderstorm centers are found to contribute to anomalous effect observed at Yongsheng station. Modeling results of SR regular and disturbed spectra at different local times led to the similar conclusion.  相似文献   

A possible substellar companion to the intermediate-mass giant HD 175679     

Liang Wang  Bun＇ei Sato  Gang Zhao  Yu-Juan Liu  Kunio Noguchi  Hirovasu Ando  Hideyuki Izumiura  Eiji Kambe  Masashi Omiya  Hiroki Harakawa  Fan Liu  Xiao-Shu Wu  Yoichi Takeda  Michitoshi Yoshida  Eiichiro Kokubo 《天体物理学报》2012,(1):84-92

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Spatial correspondence of knickzones and stream confluences along bedrock rivers in Japan: implications for hydraulic formation of knickzones     

Yuichi S. Hayakawa  Takashi Oguchi 《Geografiska Annaler: Series A, Physical Geography》2014,96(1):9-19

Knickzones, defined here as locally steep reaches including distinct knickpoints, in bedrock river morphology, have often been investigated in relation to local anomalies in lithology, tectonics, hydraulics, climate and associated base‐level change, and/or deformation of valley‐side slopes. However, exact formative causes of many knickzones in a humid, tectonically active island arc remain unclear. Using databases of geology, streams and knickzones, we examine knickzone distribution across the Japanese Archipelago to evaluate the effects of the stream network structure and rock type boundaries on knickzone formation. Knickzones are frequently found just upstream and downstream of major stream confluences along mainstreams, whereas knickzones are less frequent around major rock type boundaries. While the major confluences do not form hanging valleys due to similar catchment size, this observation suggests that many knickzones have been formed by the long‐term effect of flow turbulence scouring bedrock at the confluences. Such a hydraulic control on bedrock erosion in the steep Japanese mountains under humid climate conditions indicates that the formative cause of many knickzones therein can be autogenic by means of stream hydraulics.  相似文献   

X-ray emissions from Vela X-1 during its eclipsing period     

N. Sato  S. Hayakawa  F. Nagase 《Astrophysics and Space Science》1986,119(1):81-84

The X-ray pulsar Vela X-1 was observed with TENMA throughout the entire period of eclipse in March 1984. The energy spectra at several phase angles showed the iron emission line at about 6.4 keV throughout the eclipse of Vela X-1 and its intensity at the mid-eclipse to be about 10% of that in the non-eclipsing phase, whereas the continuum intensity was about 1%. The result provides means of studying the contribution of the stellar wind to the fluorescence line and the structure of the stellar atmosphere.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.  相似文献   

Correlation between the densities of X-ray sources and interstellar gas     

M. Fujimoto  S. Hayakawa  T. Kato 《Astrophysics and Space Science》1969,4(1):64-83

The distribution of X-ray sources in our galaxy is obtained, assuming that the absolute X-ray luminosities of these sources are the same. The distribution is found to be in good correlation with the distribution of interstellar gas. The density of X-ray sources is nearly proportional to the square density of gas. This indicates that X-ray sources are comparatively young. The relation between the densities of X-ray sources and gas allows us to estimate the X-ray intensities of various objects such as Magellanic Clouds and Andromeda nebula, and also to obtain the average X-ray luminosity of spiral galaxies. The latter should increase as the age of a galaxy decreases, since the amount of gas decreases as the galaxy evolves. Under the assumptions that the gas density is inversely proportional to the age and that galaxies older thant ₀/30 are visible in X-rays, wheret ₀ is the present age of the universe, the contribution of X-ray sources in distant galaxies to the background component is calculated. The intensity and the spectrum of the background component of X-rays thus obtained are in fair agreement with observed ones in the energy range between 1 and 4 keV but significantly deviate from the latter at high energies.  相似文献   

Production of metagalactic X-rays by relativistic dust grains     

Satio Hayakawa 《Astrophysics and Space Science》1972,19(1):173-179

The relativistic dust grains which may be responsible for ultra-high energy cosmic rays, as suggested by the present author, interact with the cosmic black-body radiation. This results in the energy loss of the relativistic dust grains, so that their energy spectrum is cut-off at the Lorentz factor as large as 2×10³ (0.1/a), wherea is the grain radius. The black-body radiation is scattered and absorbed by the dust grains. The photons scattered and reemitted contribute to metagalactic X-rays. The X-ray intensity estimated is comparable to the observed one in the soft X-ray region.  相似文献   

An impulsive solar X-ray burst in the energy range 90–400 keV     

Y. Fukada  S. Hayakawa  I. Kasahara  F. Makino  I. Suzuki  Y. Tanaka  B. V. Sreekantan 《Solar physics》1975,42(2):441-444

A hard solar X-ray burst in the energy range 90–400 keV was observed at about 0528:30 UT on 13 April 1974. This event is peculiar in the sense that the X-ray flux is considerably high whereas the corresponding radio and optical flares are of moderate sizes, that the duration of the X-ray burst is very short, and that the X-ray peak is delayed by about 2.5 min relative to the first radio peak.  相似文献   

Ultrasonically enhanced electrokinetic remediation for removal of Pb and phenanthrene in contaminated soils   总被引：5，自引：0，他引：5  

Ha Ik Chung  Masashi Kamon   《Engineering Geology》2005,77(3-4):233-242

Electrokinetic and ultrasonic remediation technologies were studied for the removal of heavy metal and polycyclic aromatic hydrocarbon (PAH) in contaminated soils. The study emphasized the coupled effects of electrokinetic and ultrasonic techniques on migration as well as clean-up of contaminants in soils. The laboratory soil flushing tests combined electrokinetic and ultrasonic technique were conducted using specially designed and fabricated devices to determine the effect of both techniques. The electrokinetic technique was applied to remove mainly the heavy metal and the ultrasonic technique was applied to remove mainly organic substance in contaminated soil. A series of laboratory experiments involving electrokinetic and electrokinetic and ultrasonic flushing tests were carried out. Natural clay was used as a test specimen and Pb and phenanthrene were used as contaminants. An increase in out flow, permeability and contaminant removal rate was observed in electrokinetic and ultrasonic tests. Some practical implications of these results are discussed in terms of technical feasibility of in situ implementation of electrokinetic ultrasonic remediation technique.  相似文献