I-1 Wave energy absorption characteristics of circular air chamber for use of light beacon     

Reisaku Inoue  Masami Iwai 《Ocean Engineering》1985,12(6):554-555

  相似文献   

Uranium, Thorium and Potassium Contents In Eighteen Geochemical Reference Samples Issued from the Geological Survey of Japan     

Kazuhisa KOMURA  Kok-Leong TAN  Kaoru UENO 《Geostandards and Geoanalytical Research》1988,12(2):371-374

Uranium, thorium and potassium contents in eighteen geochemical reference samples issued from the Geological Survey of Japan have been measured by non-destructive gamma-ray spectrometry using germanium semiconductor detectors. Results are generally in good agreement with recent values measured by various methods.  相似文献   

Relation between chemical composition and particle-size distribution of ores in the profile of nickeliferous laterite deposits of the Rio Tuba Mine, Philippines   总被引：1，自引：0，他引：1  

Yoshio Ogura  Katsuyuki Murata  Michio Iwai 《Chemical Geology》1987,60(1-4):259-271

Lateritic Ni ore mined in the Rio Tuba Mine, Philippines, derived from ultramafic rock by tropical intense weathering, is generally composed of two accumulated zones, an upper laterite zone and a lower saprolite zone. These two zones are very different in appearance, mineral assemblage, chemical composition, and in other ways. A transitional zone may be seen between the upper and lower zones, but it does not develop to any appreciable thickness. Although serpentine and goethite are still predominant in the constituent minerals, other clay minerals are increasing.

The transitional zone may be subdivided into three groups based on chemical composition. The behaviour of the chemical composition in this horizon indicates a complicated process of component transportation under the weathering process.

In the ore, chemical components are closely related in particle size of constituent minerals. In the laterite - transitional - saprolite sequence, a common variation range and tendency in chemical composition for each particle size can be seen. However, taking samples with the same particle size the chemical composition obviously differed, representing the characteristics of the components for each zone.

Concerning the correlation coefficient of the chemical components of each zone, a somewhat different inter-component relationship can be seen in these zones. These differences of correlation suggest the different complicated lateritized conditions under which they are formed.  相似文献   

积云对流参数化对一交梅雨锋暴雨过程影响的模拟检验   总被引：12，自引：10，他引：2  

彭新东  吴晓鸣 《高原气象》1999,18(3):451-461

应用１９８８年版日本谱模式ＪＳＭ,对比分析了Ａｒａｋａｗａ－Ｓｃｋａｗａ－Ｓｃｈｕｂｅｒｔ、Ｋａｉｎ－Ｆｒｉｔｓｃｈ、ＫｕｏＡｎｔｈｅｓ和Ｇａｄｄ－Ｋｅｅｒｓ等几种积云对流参数化方案在梅雨锋暴雨对流系统模拟中的表现。  相似文献   

ASCA observations of OAO 1657−415 and its dust-scattered X-ray halo     

Michael D. Audley †  Fumiaki Nagase  Kazuhisa Mitsuda  Lorella Angelini  Richard L. Kelley 《Monthly notices of the Royal Astronomical Society》2006,367(3):1147-1154

We report on two ASCA observations of the high-mass X-ray binary pulsar OAO 1657−415. A short observation near mid-eclipse caught the source in a low-intensity state, with a weak continuum and iron emission dominated by the 6.4-keV fluorescent line. A later, longer observation found the source in a high-intensity state and covered the uneclipsed through mid-eclipse phases. In the high-intensity state, the non-eclipse spectrum has an absorbed continuum component due to scattering by material near the pulsar and 80 per cent of the fluorescent iron emission comes from less than 19 light-second away from the pulsar. We find a dust-scattered X-ray halo whose intensity decays through the eclipse. We use this halo to estimate the distance to the source as 7.1 ± 1.3 kpc.  相似文献   

Simultaneous spaced direction-finding measurements of medium-latitude VLF/ELF emissions     

M. Hayakawa  Y. Tanaka  A. Iwai  J. Ohtsu  L.R.O. Storey  C. Béghin  T.S. Jorgensen 《Planetary and Space Science》1981,29(5):505-520

Simultaneous spaced measurements of medium-latitude VLF/ELF emissions were carried out during the three northern winters from 1976 to 1979. The experiment was making use of two different kinds of direction-finding systems (a field-analysis method and a goniometer network) at two stations in Europe, namely Brorfelde in Denmark (L = 2.9) and Chambron-la-Foret in France (L = 1.9); this enabled us to locate the ionospheric exit regions of emissions over a wide range of L-values up to and beyond 4.0, the average plasmapause location. In order to study the time delay in the temporal evolution of VLF emissions or the longitudinal drift of the emissions, observations from the Moshiri Observatory in Japan, widely separated in longitude, are also used. The overall system of the VLF equipment installed at the three stations is described. Then we present the VLF/ELF data of good quality obtained during the final year's campaign (Nov. 1978–Feb. 1979). By making use of the direction-finding data, we were able to classify the observed emissions into several categories, and some early results for some of the emissions are presented.  相似文献   

IPRT/AMATERAS: A New Metric Spectrum Observation System for Solar Radio Bursts     

K. Iwai  F. Tsuchiya  A. Morioka  H. Misawa 《Solar physics》2012,277(2):447-457

A new radio spectropolarimeter for solar radio observation has been developed at Tohoku University and installed on the Iitate Planetary Radio Telescope (IPRT) at the Iitate observatory in Fukushima prefecture, Japan. This system, named AMATERAS (the Assembly of Metric-band Aperture TElescope and Real-time Analysis System), enables us to observe solar radio bursts in the frequency range between 150 and 500 MHz. The minimum detectable flux in the observation frequency range is less than 0.7 SFU with an integration time of 10 ms and a bandwidth of 61 kHz. Both left and right polarization components are simultaneously observed in this system. These specifications are accomplished by combining the large aperture of IPRT with a high-speed digital receiver. Observational data are calibrated and archived soon after the daily observation. The database is available online. The high-sensitivity observational data with the high time and frequency resolutions from AMATERAS will be used to analyze spectral fine structures of solar radio bursts.  相似文献   

Investigation on piezoelectric lead zirconate titanate detector bombarded obliquely with hypervelocity iron particles     

S. Takechi  T. Onishi  T. Miyachi  N. Hasebe  K. Nogami  S. Sasaki  T. Iwai  R. Srama 《Planetary and Space Science》2008,56(9):1309-1313

A cosmic dust detector for use onboard a satellite is currently being constructed from piezoelectric lead zirconate titanate (PZT). The characteristics of the PZT detector were studied by bombarding it with hypervelocity iron particles, which were supplied by a Van de Graaff accelerator. There was a linear relationship between the rise time of the signal observed from the detector and the particle's velocity, which was above 10 km/s on impact. It was also found that the rise time was almost independent of the collisional angle between the particles and the PZT surface within the limits of the particle's parameters used in this experiment.  相似文献   

A gigantic boulder transported by the 2011 Tohoku‐oki tsunami     

Shohei Iwai  Kazuhisa Goto  Takashi Ishizawa 《Island Arc》2019,28(6)

  相似文献   

Thematic Section: Bridging the gap separating geological studies and disaster mitigation countermeasures for earthquakes and tsunami
Preface     

Kazuhisa Goto  Osamu Fujiwara  Shigehiro Fujino 《Island Arc》2010,19(3):371-373

  相似文献