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1.
Re-Os isotope systematics and fractionation of siderophile elements in metal phases from CBa chondrites 下载免费PDF全文
Nao Nakanishi Tetsuya Yokoyama Satoki Okabayashi Tomohiro Usui Hikaru Iwamori 《Meteoritics & planetary science》2018,53(5):1051-1065
We report Os isotope compositions of metal grains in two CBa chondrites (Bencubbin and Gujba) determined using a micromilling sampling coupled with thermal ionization mass spectrometry, together with the abundances of major and trace siderophile elements obtained by electron probe microanalysis and femtosecond laser ablation inductively coupled plasma–mass spectrometry. The CBa metal grains presented 187Os/188Os ratios akin to carbonaceous chondrites with limited variations (0.1257–0.1270). Most of the CBa metal grains were scattered along a 187Re-187Os reference isochron of IIIAB iron meteorites, indicating that the CBa metals experienced limited Re-Os fractionation at the time of their formation. The Re/Os ratios of sampling spots for the CBa metals, recast from the observed 187Os/188Os ratios, had a positive correlation with their Os/Ir ratios. In addition, the metal grains showed a positive correlation in a Pd/Fe versus Ni/Fe diagram. These correlations suggest that the CBa metal grains have formed via equilibrium condensation or evaporation from a gaseous reservoir at ~10−4 bar with enhanced metal abundances. Compared to the Bencubbin metals, the Gujba metals are characterized by having systematically lower Pd/Fe and Ni/Fe ratios that span subchondritic values. Such a difference was most likely induced by the compositionally heterogeneous impact plume from which the metals were condensed. 相似文献
2.
Masanori Yoshizawa Shunsaku Suzuki Rikinosuke Fukaya 《Astrophysics and Space Science》1991,177(1-2):41-45
The catalog of positions of 1007 stars (792 FK4 and FK4S stars, 57 OB stars, 49 NPZT stars, and 109 SAO stars) is presented. They were observed during the period from December 1984 to September 1985 with the Tokyo Photoelectric Meridian Circle (Tokyo PMC). The positions in the catalog are referred to the equinox and equator of J2000, and are based on the FK4 system. The internal errors of a single observation were estimated to be (
cos,
)=(0.16, 0.19), whereas the mean internal errors of the catalog positions were (0.08, 0.08) for FK4 stars and (0.09, 0.11) for FK4S stars. A comparison of the positions of the FK4 stars in the present catalog with those of the FK4 catalog shows significant differences
cos and
in some declination zones. Some of those differences are commonly found in other recent catalogs. Thus they may be considered to be real systematic errors in the FK4 system. Neither significant magnitude nor color equations exist in the Tokyo PMC 85 catalog. 相似文献
3.
Masanori Kurosawa Simon E. Jackson Shigeho Sueno 《Geostandards and Geoanalytical Research》2002,26(1):75-84
Fifty elements in NIST SRM 614 and 616 glass reference materials were determined by laser ablation microprobe-inductively coupled plasma-mass spectrometry (LAM-ICP-MS). The values determined for NIST SRM 614 agreed well with the NIST-certified and information values (mean relative difference ± 3.6%), except for B, Sc and Sb. The values determined for NIST SRM 616 agreed with the NIST-certified and information values within a mean relative difference of ± 1.5%, except for B, Sc and Ga. In addition, at an 80 μm sampling scale, NIST SRM 614 and 616 glass discs were homogeneous for trace elements within the observed precisions of 5 and 15% (mean), respectively. Detection limits were in the range 0.01 - 0.3 μg g−1 for elements of lower mass numbers (amu < 80) and 1 - 10 ng g−1 for heavy elements (amu > 80). Detection at the sub ng g−1 level is possible for most of the heavy elements by using an ablation pit size larger than 10 0 μm. 相似文献
4.
Shin Okamoto Nagahide Kani Masahiko Higashino Norihide Koshika Masayuki Kimizuka Mitsumasa Midorikawa Masanori Iiba 《地震工程与工程振动(英文版)》2002,1(2):213-225
The Building Standard Law of Japan and related Enforcement Order and Notifications have been substantially revised since the
year 2000 to introduce a performance-based regulatory and deregulation system for building control systems. Up to then, time-history
analyses were mandatory for isolated buildings and had to be specially approved by the Minster of the Ministry of Construction
(MOC). Simplified design procedures based on the equivalent linear method for seismically isolated buildings have been issued
as “Notification 2009 — Structural calculation procedure for buildings with seismic isolation” from MOC, and are now integrated
into the Ministry of Land, Infrastructure, and Transportation (MLIT). Along with Notification 2009, “Notification 1446 of
year 2000 — Standard for specifications and test methods for seismic isolation devices” was also issued. Buildings with heights
equal to or less than 60m and that are designed according to these Notifications, including base isolated buildings, only
need approval from local building officials, and no longer require the special approval of the Minister of MLIT. This paper
summarizes: 1) some statistics related to buildings with seismic isolation completed up to the end of 2001; 2) simplified
design procedures required by Notification 2009 of year 2000; and 3) performance of seismic isolation devices required by
Notification 1446 of year 2000. 相似文献
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7.
The objective of this paper is to propose an FFT technique symmetrical for time and frequency, in which the symmetrization is done by introducing generating functions. By the symmetrical treatment, it becomes possible to derive several complementary relations in the time and frequency domains. Based on the idea of the symmetrical FFT technique, the phase problem of seismic waves is discussed not only in the frequency domain but also in the time domain. Furthermore, the deconvolution technique to evaluate the minimum-phase-shift and all-pass functions of seismic waves, which is not discussed sufficiently in earthquake engineering, is developed in the two domains. Numerical examples to present these basic ideas are also illustrated in the symmetrical framework. 相似文献
8.
Intensive water sampling in conjunction with hydrological observations was conducted during three different rainstorms in order to understand the effects of rainfall events on the temporal variation of streamwater chemistry in a small headwater forest catchment. Concentrations of Na+ and SO42? decreased as the discharge rate increased. Hydrograph separation of the components was made using the three‐component model based on the end‐members mixing analysis (EMMA). The three end‐members were:
- 1 the groundwater in the saturated zone that prescribes the chemistry of the baseflow;
- 2 the throughfall that dilutes the streamwater;
- 3 the groundwater in the transient saturated zone prescribed, which was dependent on the groundwater level.
9.
Toshifumi Yanagisawa Yasushi Muraki Yutaka Matsubara Fumio Abe Kimiaki Masuda Sachiyo Noda Takahiro Sumi Yuji Kato Mitsuaki Fujimoto Shuji Sato Ian Bond Nicholas Rattenbury Philip Yock Pam Kilmartin John Hearnshaw Micheal Reid Denis Sullivan Brian Carter Richard Dodd Garry Nankivell Noiman Rumsey Morihiro Honda Maki Sekiguchi Masanori Yoshizawa Takashi Nakamura Humitaka Sato Seiji Kabe Makoto Kobayashi Yoshiyuki Watase Jun Jugaku Toshiharu Saito Barbel Koribalsky 《Experimental Astronomy》2000,10(4):519-535
We have constructed a large, mosaic CCD camera called MOA-cam2 which has 4096 × 6144-pixelsto search for gravitational microlensing events. MOA-cam2 has three4096 × 2048-pixel SITe CCD chips, which have a very high quantum efficiency (nearly 80% in the wave region 500 to 800 nm),and three buttable sides. We have placed the threechips side by side with 100 m dead space. MOA-cam2 has been installed on the 61 cm Boller and Chivens telescope of the MOA collaboration at the Mt. John University Observatory (MJUO) in NewZealand since July 1998. The field coverage is 0.92° × 1.38° per exposure. The technical details of MOA-cam2 and the first images obtained with the Boller and Chivens telescope are presented. MOA-cam2 introduces a second phase of research on gravitational microlensing by the MOA collaboration. 相似文献
10.
Diffuse Emission of CO2 from Showa-Shinzan, Hokkaido, Japan: A Sign of Volcanic Dome Degassing 总被引:1,自引:0,他引:1
Pedro A. Hernández Kenji Notsu Hiromu Okada Toshiya Mori Masanori Sato Francisco Barahona Nemesio M. Pérez 《Pure and Applied Geophysics》2006,163(4):869-881
Two soil CO2 efflux surveys were carried out in September 1999 and June 2002 to study the spatial distribution of diffuse CO2 degassing and estimate the total CO2 output from Showa-Shinzan volcanic dome, Japan. Seventy-six and 81 measurements of CO2 efflux were performed in 1999 and 2002, respectively, covering most of Showa-Shinzan volcano. Soil CO2 efflux data showed a wide range of values up to 552 g m-2 d-1. Carbon isotope signatures of the soil CO2 ranged from -0.9‰ to -30.9‰, suggesting a mixing between different carbon reservoirs. Most of the study area showed CO2 efflux background values during the 1999 and 2002 surveys (B = 8.2 and 4.4 g m-2 d-1, respectively). The spatial distribution of CO2 efflux anomalies for both surveys showed a good correlation with the soil temperature, indicating a similar origin for the
extensive soil degassing generated by condensation processes and fluids discharged by the fumarolic system of Showa-Shinzan.
The total diffuse CO2 output of Showa-Shinzan was estimated to be about 14.0–15.6 t d-1 of CO2 for an area of 0.53 km2. 相似文献