Circumstellar matter in the symbiotic binary CH cyg during its current outburst     

A. Skopal  M. F. Bode  M. Bryce  J. Meaburn  S. Tamura 《Astrophysics and Space Science》1995,224(1-2):559-560

We present optical high-resolution spectroscopy and UBV photometry of the symbiotic binary CH Cyg during the current outburst which began in 1992 February.  相似文献   

Local structure of (Ca, Sr)2 (Mg, Co, Zn) Si2O7 melilite solid-solution with modulated structure     

Takuo Tamura  Akira Yoshiasa  Kazuaki Iishi  Setsuo Takeno  Hironobu Maeda  Shuichi Emura  Kichiro Koto 《Physics and Chemistry of Minerals》1996,23(2):81-88

The local structure around Co, Zn and Sr atoms in incommensurately modulated, melilite-type X₂T¹ T ₂ ² O₇ (X=Ca and Sr, T¹=Mg, Co and Zn, T²=Si) solid-solutions has been investigated by EXAFS analyses. The modulated structure was confirmed in Ca_2-xSr_xCoSi₂O₇ solid-solutions with X=0.0 to 0.6 and for both Ca₂Mg_1-YCo_YSi₂O₇ and Ca₂Mg_1-YZn_YSi₂O₇ solid-solutions over the whole compositional range at room temperature. The actual bond-distances determined by the EXAFS method for the T¹ site (Co-, Zn-O) in the modulated structure are longer than the mean bond-distances obtained from the X-ray diffraction method. This is attributable to the libration of the T¹ tetrahedra. In the Ca_1-XSr_XCoSi₂O₇ solid-solution both the Sr-O and Co-O distances by the EXAFS method for the X-site increase from Ca end-member to Sr end-member. These increases are respectively 0.8% and 0.6%. This means the local expansions of the tetrahedral sheets and of the XO polyhedra are well matched. In the modulated Ca₂Co_1-YMg_YSi₂O₇ and Ca₂Zn_1-YMg_YSi₂O₇ solid-solutions, the actual Co-O and Zn-O distances for the T¹-sites are nearly constant in the whole compositional range. The compositional variations of the local structure around the cations in the solid-solution are different for the X and T¹ sites. It is concluded that the local geometric restriction for the size of substituted cation in X site is larger than that in T¹ site. The dimension of the tetrahedral sheet puts restriction on the size of the cations situated at the interlayer X sites. In other words, the different behavior of the local geometric restriction between the X and T¹ sites is an important feature of the melilite structure and is also related to the modulated structure.  相似文献   

Medieval coastal inundation revealed by a sand layer on the Ita lowland adjacent to the Suruga Trough,central Japan     

Yuki Sawai  Koichiro Tanigawa  Toru Tamura  Yuichi Namegaya 《Natural Hazards》2016,80(1):505-519

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High-resolution imaging polarimetry of HL Tau and magnetic field structure     

P. W. Lucas  Misato Fukagawa  Motohide Tamura  A. F. Beckford  Yoichi Itoh  Koji Murakawa  Hiroshi Suto  Saeko S. Hayashi  Yumiko Oasa  Takahiro Naoi  Yoshiyuki Doi  Noboru Ebizuka  Norio Kaifu 《Monthly notices of the Royal Astronomical Society》2004,352(4):1347-1364

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Laboratory production of monophase pyrrhotite grains using solid-solid reaction and their characteristic infrared spectra     

Y. Kimura  K. Tamura  H. Chihara  C. Kaito 《Icarus》2005,177(1):280-285

A new method of producing pyrrhotite grains, which are most commonly found in cometary material and interplanetary dust particles, was developed. Pyrrhotite grains in the monophase having a 7C structure were predominately produced using a solid-solid reaction between iron and sulfur grains at room temperature. The characteristic infrared peaks were observed at 602, 563, and 397 cm⁻¹ (16.6, 17.8, and 25.2 μm).  相似文献   

Morphology and formation of spreading cracks on pillow lavas at Cape Grim, northwestern Tasmania, Australia     

Yoshihiko Goto  Jocelyn McPhie 《Bulletin of Volcanology》2012,74(7):1611-1619

Tertiary basaltic pillow lobes at Cape Grim, northwestern Tasmania, Australia display well-preserved spreading cracks in the glassy crust. The spreading cracks are lens-shaped or rectangular in plan view. In cross section, they consist of a graben-like depression with a broad floor bounded by steep scarps. The floor of spreading crack contains an axial crack and a number of ridges that are arranged symmetrically with respect to the axial crack. The ridges within spreading cracks are inferred to have formed by the regular, repeated production and splitting of new crust at the centre of the spreading crack. This new interpretation of ridges in spreading cracks differs from the previous interpretation in which they are regarded as elongate normal fault blocks. Our interpretation provides new insight into the propagation mechanisms of pillow lavas.  相似文献   

Inaugural Address 25:1          下载免费PDF全文

Tetsuji Muto  Yoshihiko Tamura 《Island Arc》2016,25(1):3-3

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The discovery of an M4+T8.5 binary system     

Ben Burningham  D. J. Pinfield  S. K. Leggett  C. G. Tinney  M. C. Liu †  D. Homeier  A. A. West  A. Day-Jones  N. Huelamo  T. J. Dupuy  Z. Zhang  D. N. Murray  N. Lodieu  D. Barrado y Navascués  S. Folkes  M. C. Galvez-Ortiz  H. R. A. Jones  P. W. Lucas  M. Morales Calderon  M. Tamura 《Monthly notices of the Royal Astronomical Society》2009,395(3):1237-1248

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Preliminary results of the Japan-Taiwan joint survey on combining ocean radar data in the Kuroshio upstream region     

Kaoru Ichikawa  Wen Chang Yang  Akihiko Morimoto  Yutaka Yoshikawa  Shigeo Sugitani  Wen-Shan Chiang  Jian-Wu Lai  En Yu Liang  Cho-Teng Liu  Chang-Wei Lee  Kei Yufu  Moeto Kyushima  Satoshi Fujii  Tomoharu Senju  Yoshihiko Ide 《Ocean Science Journal》2013,48(1):141-148

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Spectrophotometric scan of comet 1973 XII Kohoutek     

Hisashi S. Ishii  Tetsuo Yamamoto  Shin'ichi Tamura 《Earth, Moon, and Planets》1981,25(4):437-450

Photoelectric spectrophotometric scans of Comet 1973 XII Kohoutek were made on November 25.85 and 28.85 UT, 1973. The vibrational temperature of C₂, the total numbers of CN and of C₂, and the production rates for CN and C₂ are derived from the observed fluxes. The temperature of C₂ was 4900 K on 25.85 November and 4300 K on 28.85 November. Mean abundance ratio of C₂ to CN was about 2.7. From the variation of production rates with heliocentric distance, it is shown that there was an outburst on 25.85 November in both CN and C₂ productions. For C₂, the production rates are derived by using two coma models, i.e. the Haser's parent-daughter model and the model relevant to a proposition of Yamamoto (1981b) that C₂ is formed via two-step photodissociation of its parent molecules. By comparing the production rate derived from the two models, it can be supported that C₂ is formed via two-step photodissociation rather than one-step photodissociation. In consequence, it is shown that the variation of the production rate with heliocentric distance is largely modified compared with that derived from the Haser's model.  相似文献