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Reduced activation ferritic/martensitic steels (RAFs) are one of the leading candidates for structural materials of fusion reactors. Since there are severe limitations on specimen capacity at material irradiation testing facilities, it is required to use miniaturized specimens. In the previous study, it was revealed that the small punch (SP) creep test was useful technique for evaluating the creep rupture strength of RAFs. If this SP test technique was applicable to the measurement of not only the creep properties but also the high-temperature tensile properties, it would have an important meaning from the standpoints of designing and developing more superior fusion reactor materials. In this study, the SP test were carried out at 823~923 K to investigate the applicability using two representative RAFs, JLF-1 and F82H. The experimental results revealed that the load at initial localized plastic straining, Fy, and the maximum load, Fmax, determined by the SP test were well correlated with the yield strength, σy, and the ultimate tensile strength, σB, respectively. The empirical linear correlation between the Fy and the σy was expressed by σy=1.5Fy+19. Similarly, there was an almost linear correlation between the Fmax and the σB represented by σB=0.37Fmax+86. Consequently, the high-temperature tensile properties of the RAFs can be also estimated by the SP test and the above empirical equations.

Neutron diffraction experiments on the heavy-fermion superconductor PrOs 4 Sb 12 revealed that a small antiferromagnetic moment, parallel to [010] ( y -direction), is induced in the field-induced phase ( H ∥ z ). The analysis, based on the Γ 1 singlet ground state crystal field model, shows that antiferro-order of O y z -type quadrupole moments of Pr ions is formed in the field-induced phase. This strongly suggests that the crystal field ground-state of Pr ions in PrOs 4 Sb 12 is the Γ 1 singlet and the quadrupolar ordering is induced due to level crossing with an excited state under a magnetic field.

Mikio Morii1, Hiroshi Tomida2, Masaki Kimura2, Fumitoshi Suwa3, Hitoshi Negoro3, Motoko Serino4, Jamie A. Kennea5, Kim L. Page6, Peter A. Curran7, Frederick M. Walter8, N. Paul. M. Kuin9, Tyler Pritchard5, Satoshi Nakahira2, Kazuo Hiroi10, Ryuichi Usui1, Nobuyuki Kawai1, Julian P. Osborne6, Tatehiro Mihara4, David N. Burrows5, Neil Gehrels11, Mitsuhiro Kohama2, Masaru Matsuoka4, Motoki Nakajima12, Peter W. A. Roming13, Kousuke Sugimori1, Mutsumi Sugizaki4, Yohko Tsuboi14, Hiroshi Tsunemi15, Yoshihiro Ueda10, Shiro Ueno2 and Atsumasa Yoshida16 1Department of Physics, Tokyo Institute of Technology, Ookayama 2-12-1, Meguro-ku, Tokyo 152-8551, Japan. 2ISS Science Project Office, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505, Japan. 3Department of Physics, Nihon University, 1-8-14 Surugadai, Chiyoda, Tokyo 101-8308, Japan. 4MAXI team, Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. 5Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Laboratory, University Park, Pennsylvania 16802, USA. 6Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH, UK. 7International Centre for Radio Astronomy Research / Curtin University, GPO Box U1987, Perth, WA 6845, Australia. 8Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800, USA. 9Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK. 10Department of Astronomy, Kyoto University, Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan. 11NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA. 12School of Dentistry at Matsudo, Nihon University, 2-870-1 Sakaecho-nishi, Matsudo, Chiba 271-8587, Japan. 13Southwest Research Institute, Space Science and Engineering Division, PO Drawer 28510, San Antonio, Texas 78228-0510, USA. 14Department of Physics, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan. 15Department of Earth and Space Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan. 16Department of Physics and Mathematics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258, Japan.

著者人数: 43名, Accepted: 2014-06-13, 資料番号: SA1140202000

MAXI/GSC observed 21 outbursts from Circinus X-1 between 2009 August and 2013 December. Although 14 outbursts showed ordinary gradual decays, in 7 outbursts we found sudden luminosity decrease in a time scale of a few hours around the periastron, and then the outbursts terminated. These sudden decreases started at the estimated luminosity of a few times $10^{37}$ erg s$^{-1}$ and reached to $\lesssim3\times10^{36}$ erg s$^{-1}$. We propose three interpretations for the sudden luminosity decrease: (1) the end of the outburst during the dip, (2) the propeller effect, and (3) the stripping effect by the stellar wind of the companion star. It is difficult to explain the phenomenon with any of these interpretations alone. The interpretation of (1) is possible for only two outbursts assuming rapid decay. The propeller effect (2) is expected to occur at a constant luminosity, which is incompatible with the observed facts. In wind stripping effect (3), the ram pressure of a typical stellar wind is not sufficient to blow out most of the accretion disk. In this paper, we discuss a possibility of a modified effect of (3) assuming other additional conditions such as wind clumping and disk instability., Comment: 13 pages, 7 figures

We report on the luminosity dependent change of the cyclotron resonance energy obtained from a transient X-ray pulsar, 4U 0115+63. Using RXTE data observed on 1999 March, we found that the fundamental resonance energy stayed constant (∼11 keV) when the source luminosity was above ∼5 × 1037 erg s−1. As the luminosity decreased below ∼5 × 1037 erg s−1, the fundamental resonance energy gradually increased up to ∼16 keV at 0.16 × 1037 erg s−1. The luminosity dependence of the resonance energy can be understood by the change of the accretion column height.

Monitor of All-sky X-ray Image (MAXI) is mounted on the International Space Station (ISS). Since 2009 it has been scanning the whole sky in every 92 minutes with ISS rotation. Due to high particle background at high latitude regions the carbon anodes of three GSC cameras were broken. We limit the GSC operation to low-latitude region around equator. GSC is suffering a double high background from Gamma-ray altimeter of Soyuz spacecraft. MAXI issued the 37-month catalog with 500 sources above ~0.6 mCrab in 4-10 keV. MAXI issued 133 to Astronomers Telegram and 44 to Gammaray burst Coordinated Network so far. One GSC camera had a small gas leak by a micrometeorite. Since 2013 June, the 1.4 atm Xe pressure went down to 0.6 atm in 2014 May 23. By gradually reducing the high voltage we keep using the proportional counter. SSC with X-ray CCD has detected diffuse soft X-rays in the all-sky, such as Cygnus super bubble and north polar spur, as well as it found a fast soft X-ray nova MAXI J0158-744. Although we operate CCD with charge-injection, the energy resolution is degrading. In the 4.5 years of operation MAXI discovered 6 of 12 new black holes. The long-term behaviors of these sources can be classified into two types of the outbursts, 3 Fast Rise Exponential Decay (FRED) and 3 Fast Rise and Flat Top (FRFT). The cause of types is still unknown., Comment: 6 pages, 7 figures, SPIE Astronomical Telescopes and Instrumentation

We report on the firm detection of a cyclotron resonance scattering feature (CRSF) in the X-ray spectrum of the Be X-ray binary pulsar, GRO J1008-57, achieved by the Suzaku Hard X-ray Detector during a giant outburst which was detected by the MAXI Gas Slit Camera in 2012 November. The Suzaku observation was carried out on 2012 November 20, outburst maximum when the X-ray flux reached $\sim 0.45$ Crab in 4-10 keV, which corresponds to a luminosity of $1.1 \times 10^{38}$ erg s$^{-1}$ in 0.5--100 keV at 5.8 kpc. The obtained broadband X-ray spectrum from 0.5 keV to 118 keV revealed a significant absorption feature, considered as the fundamental CRSF, at $\sim 76$ keV. This unambiguously reconfirm the previously suggested $\sim$ 80 keV spectral feature in GRO J1008$-$57. The implied surface magnetic field, $6.6\times 10^{12}$ G, is the highest among binary X-ray pulsars from which CRSFs have ever been detected.

Semantic understanding of images remains an important research challenge in machine intelligence and statistical learning. It mainly includes two steps: feature extraction and classification. This study mainly focuses scene image recognition, where color information plays an important role. The conventional color representation of images mainly includes color distribution (histogram) and its statistical information based on uniformed quantization color bin. However, for a specific recognition application such several scene types, some quantized colors maybe never appear in any scene image, and at the same time the detail variation in other quantized colors include much discriminative features. Therefore, this study proposes to characterize the color information of scene images using a leaning strategy for producing adaptive color level, and extract the histogram of the learned color levels for image representation. With the proposed strategy, the compact (learned) color levels can represent the image in our application more faithful than the uniform quantized conventional RGB color. Experimental results show that the recognition rate with our proposed methods can be greatly improved compared to the conventional color histogram.

The stellar wind around the compact object in luminous wind-accreting high mass X-ray binaries is expected to be strongly ionized with the X-rays coming from the compact object. The stellar wind of hot stars is mostly driven by light absorption in lines of heavier elements, and X-ray photo-ionization significantly reduces the radiative force within the so-called Stroemgren region leading to wind stagnation around the compact object. In close binaries like Vela X-1 this effect might alter the wind structure throughout the system. Using the spectral data from Monitor of All-sky X-ray Image (MAXI), we study the observed dependence of the photoelectric absorption as function of orbital phase in Vela X-1, and find that it is inconsistent with expectations for a spherically-symmetric smooth wind. Taking into account previous investigations we develop a simple model for wind structure with a stream-like photoionization wake region of slower and denser wind trailing the neutron star responsible for the observed absorption curve., 5 pages, 3 figures, accepted in A&A

In the last 10 years, since its last giant outburst in 2006, regular X-ray outbursts (type I) were detected every periastron passage in the Be X-ray binary EXO 2030+375. Recently, however, it was reported that the source started to show a peculiar behavior: its X-ray flux decreased significantly and type I outbursts were missed in several cases. At the same time, the spin frequency of the neutron star, which had been increasing steadily since the end of the 2006 giant outburst, reached a plateau. Very recent observations indicate that the source is now starting to spin down. These observed phenomena have a striking similarity with those which took place 20 years ago, just before the source displayed a sudden orbital phase shift of the outburst peak (1995). This historical event occurred at the time exactly between the two giant outbursts (1985 and 2006). These phenomena suggest the system to have an underlying periodicity of 10.5 years between orbital phase shifts and/or giant outbursts. The suggested periodicity may reflect some long-period dynamics in the circumstellar disk of the Be star, due, e.g., to the Kozai-Lidov effect. A model generating such a periodic change of the Be disk, namely Kozai-Lidov oscillations in the Be disk, is discussed. If this behavior is really periodical, another phase shift of the X-ray outburst peak is predicted to occur around 2016 December., 10 pages, 5 figures, accepted for publication in Astronomy & Astrophysics (A&A), included minor language corrections

We present the observation of an extraordinary luminous soft X-ray transient, MAXI J0158-744, by the Monitor of All-sky X-ray Image (MAXI) on 2011 November 11. This transient is characterized by a soft X-ray spectrum, a short duration (1.3 x 10^3 s < ��T_d < 1.10 x 10^4 s), a very rapid rise (< 5.5 x 10^3 s), and a huge peak luminosity of 2 x 10^40 erg s^-1 in 0.7-7.0 keV band. With Swift observations and optical spectroscopy from the Small and Moderate Aperture Research Telescope System (SMARTS), we confirmed that the transient is a nova explosion, on a white dwarf in a binary with a Be star, located near the Small Magellanic Cloud. An extremely early turn-on of the super-soft X-ray source (SSS) phase (< 0.44 d), the short SSS phase duration of about one month, and a 0.92 keV neon emission line found in the third MAXI scan, 1296 s after the first detection, suggest that the explosion involves a small amount of ejecta and is produced on an unusually massive O-Ne white dwarf close to, or possibly over, the Chandrasekhar limit. We propose that the huge luminosity detected with MAXI was due to the fireball phase, a direct manifestation of the ignition of the thermonuclear runaway process in a nova explosion., 33 pages, 5 figures, Accepted for publication by ApJ

We report on the spectral evolution of a new X-ray transient, MAXI J0556-332, observed by MAXI, Swift, and RXTE. The source was discovered on 2011 January 11 (MJD=55572) by MAXI Gas Slit Camera all-sky survey at (l,b)=(238.9deg, -25.2deg), relatively away from the Galactic plane. Swift/XRT follow-up observations identified it with a previously uncatalogued bright X-ray source and led to optical identification. For more than one year since its appearance, MAXI J0556-332 has been X-ray active, with a 2-10 keV intensity above 30 mCrab. The MAXI/GSC data revealed rapid X-ray brightening in the first five days, and a hard-to-soft transition in the meantime. For the following ~ 70 days, the 0.5-30 keV spectra, obtained by the Swift/XRT and the RXTE/PCA on an almost daily basis, show a gradual hardening, with large flux variability. These spectra are approximated by a cutoff power-law with a photon index of 0.4-1 and a high-energy exponential cutoff at 1.5-5 keV, throughout the initial 10 months where the spectral evolution is mainly represented by a change of the cutoff energy. To be more physical, the spectra are consistently explained by thermal emission from an accretion disk plus a Comptonized emission from a boundary layer around a neutron star. This supports the source identification as a neutron-star X-ray binary. The obtained spectral parameters agree with those of neutron-star X-ray binaries in the soft state, whose luminosity is higher than 1.8x10^37 erg s^-1. This suggests a source distance of >17 kpc., 14 pages, 8 figures, accepted for publication in PASJ

We present analysis of 4U 1626-67, a 7.7 s pulsar in a low-mass X-ray binary system, observed with the hard X-ray detector of the Japanese X-ray satellite Suzaku in March 2006 for a net exposure of \sim88 ks. The source was detected at an average 10-60 keV flux of \sim4 x10^-10 erg cm^-2 s^-1. The phase-averaged spectrum is reproduced well by combining a negative and positive power-law times exponential cutoff (NPEX) model modified at \sim 37 keV by a cyclotron resonance scattering feature (CRSF). The phase-resolved analysis shows that the spectra at the bright phases are well fit by the NPEX with CRSF model. On the other hand, the spectrum in the dim phase lacks the NPEX high-energy cutoff component, and the CRSF can be reproduced by either an emission or an absorption profile. When fitting the dim phase spectrum with the NPEX plus Gaussian model, we find that the feature is better described in terms of an emission rather than an absorption profile. The statistical significance of this result, evaluated by means of an F-test, is between 2.91 x 10^-3 and 1.53 x 10^-5, taking into account the systematic errors in the background evaluation of HXD-PIN. We find that, the emission profile is more feasible than the absorption one for comparing the physical parameters in other phases. Therefore, we have possibly detected an emission line at the cyclotron resonance energy in the dim phase., Accepted for publication in ApJ on March 16, 2012. 12 pages, 14 figures

著者人数: 31名, Accepted: 2012-01-28, 資料番号: SA1004313000

著者人数: 38名, Accepted: 2011-08-19, 資料番号: SA1003132000

We report the discovery of a cyclotron resonance scattering feature (CRSF) in the X-ray spectrum of GX 304-1, obtained by RXTE and Suzaku during major outbursts detected by MAXI in 2010. The peak intensity in August reached 600 mCrab in the 2-20 keV band, which is the highest ever observed from this source. The RXTE observations on more than twenty occasions and one Suzaku observation revealed a spectral absorption feature at around 54 keV, which is the first CRSF detection from this source. The estimated strength of surface magnetic field, $4.7 \times 10^{12}$ G, is one of the highest among binary X-ray pulsars from which CRSFs have ever been detected. The RXTE spectra taken during the August outburst also suggest that the CRSF energy changed over 50-54 keV, possibly in a positive correlation with the X-ray flux. The behavior is qualitatively similar to that observed from Her X-1 on long time scales, or from A 0535+26, but different from the negative correlation observed from 4U 0115+63 and X 0331+53., 7 pages, 4 figures, accepted for publication in PASJ

We report the in-orbit performance of the Gas Slit Camera (GSC) on the MAXI (Monitor of All-sky X-ray Image) mission carried on the International Space Station (ISS). Its commissioning operation started on August 8, 2009, confirmed the basic performances of the effective area in the energy band of 2--30 keV, the spatial resolution of the slit-and-slat collimator and detector with 1.5 degree FWHM, the source visibility of 40-150 seconds for each scan cycle, and the sky coverage of 85% per 92-minute orbital period and 95% per day. The gas gains and read-out amplifier gains have been stable within 1%. The background rate is consistent with the past X-ray experiments operated at the similar low-earth orbit if its relation with the geomagnetic cutoff rigidity is extrapolated to the high latitude. We also present the status of the in-orbit operation and the calibration of the effective area and the energy response matrix using Crab-nebula data., 11 pages, 14 figures, accepted for publication in PASJ

著者人数: 37名, Accepted: 2011-09-06, 資料番号: SA1004479000

MAXI, the first astronomical payload on JEM-EF of ISS, began operation on August 3, 2009 for monitoring all-sky X-ray images every ISS orbit (92 min). All instruments as well as two main X-ray slit cameras, the GSC and SSC, worked well as expected for one month test operation. The MAXI has been operated since August, 2009 and monitored more than 300 X-ray sources, which include Galactic black holes and black hole candidates (BH/BHC), transient X-ray pulsars, X-ray novae, X-ray bursts, CVns, a considerable number of AGNs and so on. Automatic nova-alert and rapid report system is starting up, while we have published more than 30 results publicly on GCN and ATel with manual analysis. We are also releasing daily data more than 200 targets publicly. Now MAXI has continued steady operation since the beginning of 2010 although capability of a part of X-ray detectors is going down from initial ability. We have obtained some remarkable results concerning BH/BHC, X-ray pulsars and AGNs. As one of the results XTE J1752-223, an X-ray nova accompanying a black hole candidate, has revealed an evolution of accretion disc and high energy plasma from the data for seven-month observations. In this paper we report the operation status of MAXI on the ISS as well as early several astronomical results.

In order to clarify the effect of hydrogen on oxidation, the austenitic stainless steel SUSF316L was charged with hydrogen by the means of cathodic electrolysis and then the hydrogen-charged steel was subjected to the oxidation test in simulated BWR environment. Experimental results revealed that the size of oxide particle formed on the outer layer increased with increasing hydrogen content, resulting in the hydrogen accelerated oxidation (HAO). Additionally, the oxide of the hydrogen-charged steel was mainly NiFe2 O4 , whereas Fe3 O4 was predominantly formed on the non-charged one. The effect of hydrogen on the oxidation was almost equivalent to that of applied stress.Copyright © 2010 by ASME

We report on changes of the cyclotron resonance energies of the recurrent transient pulsar, X0331+53 (V0332+53). The whole RXTE data acquired in the 2004-2005 outburst were utilized. The 3-80 keV source luminosity varied between 1.7x10^36 and 3.5x10^38 ers/s, assuming a distance of 7 kpc. We confirmed that the fundamental cyclotron resonance energy changed from ~22 to ~27 keV in a clear anti-correlation to the source luminosity, and without any hysteresis effects between the rising and declining phases of the outburst. In contrast, the second harmonic energy changed from ~49 to ~54 keV, implying a weaker fractional change as a function of the luminosity. As a result, the observed resonance energy ratio between the second harmonic and the fundamental was ~2.2 when the source was most luminous, whereas the ratio decreased to the nominal value of 2.0 at the least luminous state. Although the significance of this effect is model dependent, these results suggest that the fundamental and second harmonic resonances represent different heights in the accretion column, depending on the mass accretion rate., Comment: 39 pages, 15 figures, 4 tables. Accepted for publication in Astrophysical Journal

著者人数：32名, Accepted: 2009-05-28, 資料番号: SA1001001000

Spectral and timing studies of Suzaku ToO observations of two SGRs, 1900+14 and 1806-20, are presented. The X-ray quiescent emission spectra were well fitted by a two blackbody function or a blackbody plus a power law model. The non-thermal hard component discovered by INTEGRAL was detected by the PIN diodes and its spectrum was reproduced by the power law model reported by INTEGRAL. The XIS detected periodicity P = 5.1998+/-0.0002 s for SGR 1900+14 and P = 7.6022+/-0.0007 s for SGR 1806-20. The pulsed fraction was related to the burst activity for SGR 1900+14., 8 pages, 3 figures, Accepted for publication in PASJ (Suzaku 3rd special issue)

Monitor of All-sky X-ray Image (MAXI) is an X-ray all-sky monitor, which will be delivered to the International Space Station (ISS) by a space shuttle crew in early 2009, to scan almost the entire sky once every 96 minutes for a mission life of two to five years. The detection sensitivity will be 5 mCrab (5σlevel) for a one-day MAXI operation, 2 mCrab for one week, and 1 mCrab for one month, reaching a source confusion limit of 0.2 mCrab in two years. In this paper, brief descriptions are presented for the MAXI mission and payload, and three operation phases, 1) the launch-to-docking phase, 2) the initial in-orbit calibration phase, and 3) the routine operation phase. We also describes the MAXI data product and its release plan for public users.

MAXI (Monitor of All-sky X-ray Image) is a payload on board the International Space Station, and will be launched on April 2009. We report on the current development status on MAXI, in particular on the two types of X-ray camera (GSC and SSC), and the simulation results of the MAXI observation. SSC is a CCD camera. The moderate energy resolution enables us to detect the various emission peak including 0.5 keV oxygen line. The averaged energy resolution at the CCD temperature of -70 deg is 144.5 eV (FWHM) for 5.9 keV X-ray. GSC includes proportional gas counters, which have large X-ray detection area (5350cm 2 ). The averaged position resolution of 1.1mm at 8 keV enable us to determined the celestial position of bright sources within the accuracy of 0.1 degree. The simulation study involving the results of performance test exhibits the high sensitivity of MAXI as designed.

MAXI is the first payload to be attached on JEM-EF (Kibo exposed facility) of ISS. It provides an all sky X-ray image every ISS orbit. If MAXI scans the sky during one week, it could make a milli-Crab X-ray all sky map excluding bright region around the sun. Thus, MAXI does not only inform X-ray novae and transients rapidly to world astronomers if once they occur, but also observes long-term variability of Galactic and extra-Galactic X-ray sources. MAXI also provides an X-ray source catalogue at that time with diffuse cosmic X-ray background. MAXI consists of two kinds of detectors, position sensitive gas-proportional counters for 2-30 keV X-rays and CCD cameras for 0.5-10 keV X-rays. All instruments of MAXI are now in final phase of pre-launching tests of their flight modules. We are also carrying out performance tests for X-ray detectors and collimators. Data processing and analysis software including alert system on ground are being developed by mission team. In this paper we report an overview of final instruments of MAXI and capability of MAXI.

High Cr ferritic steels have a complex lath martensitic structure consisting of several microstructural units, i.e., fine lath, block, packet and prior austenite grain. Additionally, precipitation, solid-solution and dispersion strengthening mechanisms contribute to their excellent strength. However, it is by no means easy to separate the contributions of such strengthening factors and quantitatively understand them because of the extremely fine and complicated microstructure. In this study, the instrumented indentation test was carried out to clarify the change in contribution of each microstructural factor, particularly, “block” during creep. The material used in this study was turbine rotor steel (Fe-10Cr-1Mo-1W-VNbN). The indentation test was applied to the as-tempered and the creep damaged specimens under a wide variety of maximum loads. The test results revealed that the decrease in contribution of block grain was the predominant factor of the decrease in macroscopic hardness at the early stage of creep life. On the other hand, during the second half of the life, the decrease in macroscopic hardness was mainly caused by the decrease in matrix hardness. The decrease in block’s contribution was attributable to the decrease in the resistance of block boundary to deformation, rather than the coarsening of block grain.Copyright © 2007 by ASME

Monitor of All-sky X-ray Image (MAXI) is an X-ray all-sky monitor, which will be delivered to the International Space Station (ISS) in 2008, to scan almost the whole sky once every 96 minutes for a mission life of two years. The detection sensitivity will be 7~mCrab (5$\sigma$ level) in one scan, and 1~mCrab for one-week accumulation. At previous SPIE meetings, we presented the development status of the MAXI payload, in particular its X-ray detectors. In this paper, we present the whole picture of the MAXI system, including the downlink path and the MAXI ground system. We also examine the MAXI system components other than X-ray detectors from the point of view of the overall performance of the mission. The engineering model test of the MAXI X-ray slit collimator shows that we can achieve the position determination accuracy of $

Magnetic, transport, and x-ray diffraction measurements on single-crystal CeRhAs, the so-called Kondo insulator, have revealed successive transitions at ${T}_{1}=370,$ ${T}_{2}=235,$ and ${T}_{3}=165\mathrm{K}.$ Below ${T}_{1},$ the unit cell is doubled along the b and c axes. Thereby, the resistivity jumps upwards and magnetic susceptibility in all the directions drops. Superlattice reflections at (0,1/3,1/3) and (1/3,0,0) appear at $Tl{T}_{2}.$ The latter suddenly increases below ${T}_{3}$ where a transport gap is enhanced. These observations indicate that the gap formation is intimately related to lattice modulations.

MAXI is an all sky X‐ray monitor to be mounted on the Japanese Experimental Module in the International Space Station (ISS). It scans almost all over the sky every 96 minutes, in the course of the orbital motion of the ISS. MAXI is designed to have a sensitivity, significantly higher than the previous X‐ray monitors, and then, to detect X‐ray sources as faint as 1 mCrab in a week observation. Therefore, MAXI is expected to create a novel catalogue of not only the stable X‐ray sources but also the highly variable ones in the sky, especially active galactic nuclei for the first time. If MAXI detects X‐ray phenomena, alerts will be quickly made through the Internet.

Over the 3-year active period from 2008 September to 2011 November, the outburst behavior of the Be/X-ray binary A 0535+26 was continuously monitored with the MAXI/GSC and the Swift/BAT. The source exhibited nine outbursts, every binary revolution of 111.1 days, of which two are categorized into the giant (type-II) outbursts. The recurrence period of these outbursts is found to be $\sim115$ days, significantly longer than the orbital period of 111.1 days. With the MAXI/GSC, a low-level active period, or a "precursor", was detected prior to at least four giant outbursts. The precursor recurrence period agrees with that of the giant outbursts. The period difference of the giant outbursts from the orbital period is possibly related with some structures in the circumstellar disc formed around the Be companion. Two scenarios, one based on a one-armed disc structure and the other a Be-disc precession, are discussed., 15 pages, 7 figures, 1 table. Accepted for publication in PASJ

MAXI (Monitor of All sky X-ray Image) is the first X-ray observation payload to be installed to EF (Exposed Facility) of Kibo (JEM: Japanese Experiment Module) on ISS (International Space Station). One of the important missions of MAXI is to quickly release novae or transient information of X-ray sources through its alert system to the worldwide astronomers. For this purpose, MAXI is equipped with a unique data transfer system both for the ground and on-board handling, which fully utilizes the communication system of ISS. The uniqueness of the data transfer system of MAXI comes from the fact that it is a payload of ISS, and is not seen in the ordinary payloads on free flyers (satellites). MAXI analyzes the observation data automatically in real time, and an alert for the novae or transient sources can be distributed widely through internet based on the analysis result. Various restrictions are imposed to keep tight security even on the ground system of ISS payloads. This paper describes the data transmission process in each stage, namely that in MAXI, the ISS communication links between the ISS and ground, and the process in the MAXI ground system.

Monitor of All-sky X-ray Image (MAXI) is an X-ray all-sky scanner, which will be attached on Exposed Facility of Japanese Experiment Module dubbed "Kibo" of International Space Station (ISS). MAXI will be launched by the Space Shuttle or the Japanese H-IIA Transfer Vehicle (HTV) in 2008. MAXI carries two types of X-ray cameras: Solid-state Slit Camera (SSC) for 0.5-10 keV and Gas Slit Camera (GSC) for 2-30 keV bands. Both have long narrow fields of view (FOV) made by a slit and orthogonally arranged collimator plates (slats). The FOV will sweep almost the whole sky once every 96 minutes by utilizing the orbital motion of ISS. Then the light curve of an X-ray point source become triangular shape in one transit. In this paper, we present the actual triangular response of the GSC collimator, obtained by our calibration. In fact they are deformed by gaps between the slats, leaning angle of the slats, and the effective width of the slats. We are measuring these sizes by shooting X-ray beams into the detector behind the collimator. We summarize the calibration and present the first compilation of the data to make the GSC collimator response, which will be useful for public users.

The current status is reported of the development of Monitor of All-sky X-ray Image and the measurement of its observational response. MAXI is a scanning X-ray camera to be attached to the Japanese Experiment Module of the International Space Station in 2008. MAXI is mainly composed of two kinds of instruments, GSC which is sensitive to the 2 - 30 keV photons, and SSC to the 0.5 - 10 keV ones. As an X-ray all-sky monitor, MAXI has an unprecedented sensitivity of 7 mCrab in one orbit scan, and 1 mCrab in one week. Using the engineering mode of the proportional counter and of the collimator for GSC, the observational response of GSC is extensively measured. The acceptable performances are obtained as a whole for both the collimator and the counter. The engineering models of the other part of MAXI are also constructed and the measurement of their performance is ongoing.

(1) アリル芥子油のメタノール溶液中での変化について調べ,第1段階の変化生成物がメチルアリルチオカーバメイトであることを確認した。(2) 他のアルキル芥子油もアリル芥子油同様の反応によりそれぞれに対応するメチルアルキルチオカーバメイトに変化することを確認した。(3) 芥子油類は電子供与基の存在する溶液中ではチオカーバメイトを経由して分解することが分った。