Chaos in cosmic ray air showers     

Takashi Kitamura  Soji Ohara  Takeharu Konishi  Katsufumi Tsuji  Michiyuki Chikawa  Wasaburo Unno  Isao Masaki  Kenji Urata  Yukihiro Kato 《Astroparticle Physics》1997,6(3-4):279-291

Unexpected chaotic features are found in time series of arrival time intervals of successive air showers with (E > 3 × 10¹⁴ eV). Over 99 % of air shower arrival time intervals obey the Poisson distribution law representing stochastic behaviors, but occasionally there are air showers showing real chaotic behaviors as distinguished from both random and colored noises. With two systems of the Kinki university installations, we found 13 cases showing chaotic time series in 3.36 yr with the system-1 and the 1.37 yr with the system-2. Five out of 10 chaotic air showers of the Kinki installation are detected during the same time zone also by the Osaka City university installation which is at 115 km distance from the Kinki one. In a remarkable example of September 19, 1991, the correlation dimension was observed to have dropped from about 4 to the minimum of 1.3 and recovered smoothly in about 38 h. The chaos structure in this case is detected in nearly the same time zone at the Ohya station of the Institute for Cosmic Ray Research, University of Tokyo, which is separated from the Kinki one by 460 km. Formation of chaos structure due to energetic cosmic ray dust particles is suggested. Progress of cosmic ray physics may be expected with the study of air showers marked with chaos.  相似文献   

SELENE project status     

Konishi Hisahiro  Manabu Kato  Susumu Sasaki  Yoshisada Takizawa  Hitoshi Mizutani 《Journal of Earth System Science》2005,114(6):771-775

SELENE (Selenological and Engineering Explorer) project started as a joint mission of the former ISAS (Institute of Space and Astronautical Science) and the former NASDA (National Space Development Agency: the two organizations were merged into JAXA in 2002) of Japan in 1998. The launch target is rescheduled for 2006 due to delay of completion of launch vehicle, H-IIA. The SELENE project is now under a sustained design phase. The flight model components were manufactured, and the interface tests between the bus-system and the mission instruments were completed by the end of March 2004. The functional checks and calibration for the flight model components are being carried out at present. From the beginning of 2005, the final assembly tests will start.  相似文献   

New Accurate Bence-Albee α-Factors for Oxides and Silicates Calculated from the PAP Correction Procedure     

Takenori Kato 《Geostandards and Geoanalytical Research》2005,29(1):83-94

A new α-factor table for the Bence-Albee correction method of quantitative electron microprobe analysi is presented for an accelerating voltage of 15 kV and a take-off angle of 40 degrees. The α-factors were calculated from the full PAP correction with least squares fitting in the range 0.1–50% m/m in C/K-C space, with the assumption that C/K = 1 for C = 1, where C is the weight fraction of the emitting element as oxide or anion in binary oxide-oxide, oxide-anion or anion-anion systems, and K is the relative X-ray intensity ratio between compound and pure oxide or anion. Recently determined mass attenuation coefficients were chosen. X-ray intensities were calculated for binary oxide-oxide, oxide-anion and anion-anion systems. For the twelve major elements that characterise most geological samples, maximum deviations of α-factors in this study were smaller than 10 % and most deviations were less than 1%. The new α-factor table improves the accuracy of the Bence-Albee method compared with previous studies, and provides results as accurate as the full PAP correction when absorption is not large.  相似文献   

Radiolarian Age of Red Chert from the Kunimiyama Ferromanganese Deposit in the Northern Chichibu Belt, Central Shikoku, Japan     

Koichiro Fujinaga  Yasuhiro Kato 《Resource Geology》2005,55(4):353-356

Abstract. The radiolarian age of red chert from the Kunimiyama area of the Northern Chichibu Belt was determined in order to constrain the depositional age of the Kunimiyama deposit that is among the largest ferromanganese deposits in Japan. Pseudoalbaillella cf scalprata Holdsworth and Jones, Pseudoalbaillella cf longicornis Ishiga and Imoto and Pseudoalbaillella sp. belonging to the Ps. lomentaria Zone are found in the red chert, indicating an age of middle Early Permian (middle Wolfcampian). The red chert occurs immediately above the ferromanganese deposit, and the boundary between them is gradual. Based on their mode of occurrence and geochemical features, it is most likely that radiolarian chert and ferromanganese precipitate accumulated simultaneously to produce red chert during the waning stage of submarine hydrothermal activity that was responsible for the Kunimiyama deposit. Consequently, the age of Kunimiyama stratiform ferromanganese deposit is constrained as middle Early Permian (middle Wolfcampian).  相似文献   

Radiolarian Age of Manganese Ore and Red Chert from the Ananai Stratiform Manganese Deposit in the Northern Chichibu Belt, Central Shikoku, Japan     

Kiyoko Kuwahara    Koichiro Fujinaga  Yasuhiro Kato 《Resource Geology》2006,56(4):415-421

Abstract. We obtain radiolarian fossils such as Follicucullus monacanthus, Pseudoalbaillella aff. globosa, Pseudoalbaillella cf fusiformis , and Pseudoalbaillella spp. belonging to the Pseudoalbaillella globosa and Follicucullus monacanthus Zones from manganese ore and associated red chert of the Ananai stratiform manganese deposit in the Northern Chichibu Belt, central Shikoku. The depositional age of the Ananai ore deposit is constrained as Guadalupian (Middle Permian) that is between 270.6 and 260.4 Ma in the updated geologic time scale.  相似文献   

Seismic performance evaluation of non‐structural components: drywall partitions     

Tae‐Hyung Lee  Mikiko Kato  Tomohiro Matsumiya  Keiichiro Suita  Masayoshi Nakashima 《地震工程与结构动力学》2007,36(3):367-382

As the first part of non‐structural component test series, interior drywall partitions are selected for an experimental program. This test series will cover non‐structural components that are significant in the economic losses in buildings subjected to seismic loading, namely interior drywall partitions, exterior cladding and window glasses, and ceilings. Four full‐scale drywall partitions with light‐gage steel stud framing were tested to observe damage in cyclic loading conditions. Effects of a door and an intersecting wall on the behaviour of drywall partition are studied. Damage was concentrated to perimeter regions where gypsum boards made contacts with ceiling, floor, or columns. Dynamic loading did not amplify the damage on a drywall partition over the damage observed from the quasi‐static test. Damage–repair cost relationships show that the repair cost reaches almost the initial cost under 2% radian interstorey drift. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Influence of contamination on banded iron formations in the Isua supracrustal belt,West Greenland: Reevaluation of the Eoarchean seawater compositions     

Shogo Aoki  Chiho Kabashima  Yasuhiro Kato  Takafumi Hirata  Tsuyoshi Komiya 《地学前缘(英文版)》2018,9(4):1049-1072

Banded Iron Formations(BIFs) are chemical sediments, ubiquitously distributed in the Precambrian supracrustal belts; thus their trace element compositions are helpful for deciphering geochemical evolution on the Earth through time. However, it is necessary to elucidate factors controlling the whole-rock compositions in order to decode the ancient seawater compositions because their compositions are highly variable. We analyzed major and trace element contents of the BIFs in the 3.8-3.7 Ga Isua supracrustal belt(ISB), southern West Greenland. The BIFs are petrographically classified into four types:Black-,Gray-, Green-and White-types, respectively. The Green-type BIFs contain more amphiboles, and are significantly enriched in Co, Ni, Cu, Zn, Y, heavy rare earth element(HREE) and U contents. However,their bulk compositions are not suitable for estimate of seawater composition because the enrichment was caused by secondary mobility of metamorphic Mg, Ca and Si-rich fluid, involvement of carbonate minerals and silicate minerals of olivine and pyroxene and/or later silicification or contamination of volcanic and clastic materials. The White-type BIFs are predominant in quartz, and have lower transition element and REE contents. The Gray-type BIFs contain both quartz and magnetite. The Black-type BIFs are dominated by magnetite, and contain moderate to high transition element and REE contents. But,positive correlations of V, Ni, Zn and U contents with Zr contents suggest that involvement of detrital,volcanic and exhalative materials influences on their contents. The evidence for significant influence of the materials on the transition element contents such as Ni in the BIFs indicates the transition element contents in the Archean ocean were much lower than previously estimated. We reconstructed secular variations of V,Co, Zn and U contents of BIFs through time, which show Ni and Co contents decreased whereas V, Zn and U contents increased through time. Especially, the Ni and Co contents drastically decreased in the Mesoarchean rather than around the Great Oxidation Event. On the other hand, the V,Zn and U contents progressively increased from the Mesoarchean to the Proterozoic. Stratigraphical trends of the BIFs show increase in Y/Ho ratios and decrease in positive Eu anomaly upwards, respectively. The stratigraphic changes indicate that a ratio of hydrothermal fluid to seawater component gradually decrease through the deposition, and support the Eoarchean plate tectonics, analogous to the their stratigraphic variations of seafloor metalliferous sediments at present and in the Mesoarchean.  相似文献   

Complex Earthquake Cycle Simulations Using a Two-Degree-of-Freedom Spring-Block Model with a Rate- and State-Friction Law     

Yuta Abe  Naoyuki Kato 《Pure and Applied Geophysics》2013,170(5):745-765

Numerical simulations of complex earthquake cycles are conducted using a two-degree-of-freedom spring-block model with a rate- and state-friction law, which has been supported by laboratory experiments. The model consisted of two blocks coupled to each other and connected by elastic springs to a constant-velocity, moving driver. By widely and systematically varying the model parameters, various slip patterns were obtained, including the periodic recurrence of seismic and aseismic slip events, and several types of chaotic behaviour. The transition in the slip pattern from periodic to chaotic is examined using bifurcation diagrams. The model system exhibits typical period-doubling sequences for some parameter ranges, and attains chaotic motion. Simple relationships are found in iteration maps of the recurrence intervals of simulated earthquakes, suggesting that the simulated slip behaviour is deterministic chaos. Time evolutions of the cumulative slip distance in chaotic slip patterns are well approximated by a time-predictable model. In some cases, both seismic and aseismic slip events occur at a block, and aseismic slip events complicate the earthquake recurrence patterns.  相似文献   

Features of the orbital variability in the brightness of the WZ Sge type dwarf nova V1108 Her     

E. P. Pavlenko  T. Kato  O. I. Antonyuk  A. Imada  R. Ishioka  H. Maehara 《Astrophysics》2011,54(4):483-495

Results are presented from photometric studies of the dwarf nova V1108 Her conducted at the primary focus of the 2.6-m G. A. Shajn Telescope at the Crimean Astrophysical Observatory during June-July 2008, 4 years after the 2004 outburst. An orbital period of 0.05672(4) days is found for the system. An analysis of observations made earlier during the 2004 outburst reveals an orbital signal which indicates that V1108 Her is an eclipsing system. The mass ratio of the secondary component to the white dwarf is estimated to be q = 0.068, which makes it highly likely that the secondary component of this system is a brown dwarf. The orbital light curves indicate a complex structure for the accretion disk whose radius has reached a 2:1 resonance. An explanation is suggested for a quasi-periodic modulation in the brightness at 1/4 of the orbital period observed in V1108 Her and other WZ Sge systems.  相似文献