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It is now firmly established that a small anisotropy of the galactic cosmic rays exists, observable from Earth as a variation of intensity in sidereal time. The problem now is to determine more clearly the characteristics of the anisotropy and, in particular, its detailed spatial structure and how it depends upon the energy and composition of the cosmic rays. This is a very difficult task and, in the final analysis, may not be fully achievable from Earth-based observations. The purpose of the present paper is to describe briefly an installation now operating in Tasmania to provide further information on the spatial structure of the anisotropy.
We describe the current, 9-spacecraft Interplanetary Network (IPN). The IPN detects about
325 gamma-ray bursts per year, of which about 100 are not localized by any other missions.
We give some examples of how the data, which are public, can be utilized.
Bulk EuTiO3 is known as a compound in which spin and soft phonon mode is strongly coupled. Recent theoretical study suggests that application of stress or formation of strain leads to a drastic change in magnetic and dielectric properties of EuTiO3 and that so-called multiferroic properties emerge under such a situation. In the present study, effect of strain induced by a substrate, on which EuTiO3 thin film is deposited, on the magnetic properties of the film has been experimentally examined. By using a pulsed laser deposition method, EuTiO3 thin film has been deposited on different kinds of substrate, i.e., LaAlO3, SrTiO3, and DyScO3; the lattice parameter of these compounds is smaller than, just the same as, and larger than that of EuTiO3, respectively. X-ray diffraction analysis confirms that the strain induced in the plane of as-deposited EuTiO3 thin films on different substrates is coincident with the lattice parameter of the substrate compounds. Also, all the as-deposited EuTiO3 thin films manifest elongation of lattice in a direction perpendicular to the film surface. Temperature dependence of magnetization indicates that all the thin films exhibit ferromagnetic behavior at low temperatures. The magnetization at 2 K under a magnetic field of 100 Oe is the highest for EuTiO3 on DyScO3 and the lowest for EuTiO3 on LaAlO3. The experimental result is coincident with the first-principles calculations which predict that ferromagnetic spin configuration becomes more stable as the lattice volume of EuTiO3is increased.
Human salmonellosis cases, particularly those caused by Salmonella Enteritidis, have been closely linked to egg consumption. This epidemiological survey was conducted to determine the baseline Salmonella prevalence and identify the risk factors for Salmonella prevalence in laying-hen farms in Japan. Caecal excrement samples and dust samples were obtained from 400 flocks in 338 laying-hen farms. Salmonella was identified in 20·7% of the farms and 19·5% of the flocks. The prevalence of Salmonella was significantly higher in flocks reared in windowless houses than in those reared in open houses. In addition, the risk of Salmonella presence was significantly higher when the windowless house farms implemented induced moulting or in-line egg processing. Efforts to reduce human salmonellosis in Japan should continue to focus on the establishment of control measures in laying-hen farms, especially those with windowless houses implementing induced moulting and equipped with in-line egg processing.
Electroabsorption spectroscopy of well-identified index-defined semiconducting carbon nanotubes is reported. The measurement of high definition electroabsorption spectra allows direct indexation with unique nanotube chirality. Results show that at least for a limited range of diameters, electroabsorption is directly proportional to the exciton binding energy of nanotubes. Electroabsorption is a powerful technique which directly probes into carbon nanotube excitonic states, and may become a useful tool for in situ study of excitons in future nanotube-based photonic devices such as electroabsorption modulators.
The orbital ordering in perovskite-type vanadium oxides, RVO3 (R: rare earth), has been investigated by resonant X-ray scattering (RXS) near the V K-edge energy. The G-type orbital order, C-type orbital order and orbital disorder phases are elucidated on the basis of the azimuthal-angle and polarization dependence of the RXS signal reflecting the orbital ordering.
We report the results of mid- to far-infrared spectroscopic
observations of Galactic star-forming regions with ISO, Spitzer, and
AKARI. Owing to the high sensitivity of the IRS onboard Spitzer, we
detected [Si II] 35 μm, [Fe II] 26 μm, and [Fe III] 23 μm lines widely
in low-density star-forming regions, and derived gas-phase Si and Fe
abundances as 3–100% and <22%, respectively. With the FTS
onboard AKARI, we obtained the spatial distribution of
the [O III] 88 μm emission in two star-forming regions.
Antarctica offers probably the best ground-based conditions for observing
in the 1–3 μm region, and may thus be considered as an alternative to
Space for this domain. We examine the potential of integral-field
spectro-photometry over wide areas of the sky in this wavelength range
for the study of carbon stars, that seems promising. On the other hand,
the conditions of transparency, background, and their short-time
stability from Antarctic sites still need to be evaluated.
We investigated two-stage combinations from three methods, nulling interferometer, nulling coronagraph, and modified pupil, calculating reduced intensity profile of a resolved central star and transmission for exo-planets. An achievable dynamic range can be derived by dividing the residual halo intensity of the star by the transmitted peak intensity of the planet. For observation parameters, here assumed are the wavelength of 600 nm in optical and the telescope diameter of 3 m. The combination of the nulling interferometer and the four-quadrant phase mask coronagraph showed the best performance reaching to $10^{-10}$ dynamic range at 100mas distance from the central star among five candidates of combination using nulling interferometer, achromatic interfero-coronagraph, four-quadrant phase mask, and shaped pupil method.
As of early $\sim$2010's, the Japanese SPace Infrared telescope for Cosmology and Astrophysics (SPICA) space observatory will be launched. This actively cooled, cryogenic (4.5K), 3.5m telescope will operate in the mid and far infrared spectral regions. With its very high sensitivity, one of SPICA's aims will be the direct detection and characterization of extra-solar outer planets of nearby stars. The goal contrast ranges from $10^5$ to $10^6$ up to an angular separation of ${\sim}5$ arcsec. The relatively low angular resolution at MIR (5 to 20 $\mu$m) requires an efficient and robust coronagraphic mode working at cryogenic temperatures. In this presentation we describe several envisaged preliminary designs and assess their performance against the science goals and host telescope specifications. These are compared against numerical simulations and instrumental environment considerations, such as the need for an actively corrected wavefront.
Size control of silicon nanowires (SiNWs) synthesized by laser ablation of a Si target with nickel (Ni) as catalysts were investigated. The diameter of SiNWs decreased with decreasing synthesis temperature and content of Ni catalyst. Gradual down shift and asymmetric broadening of Si optical phonon peak depending on the diameter of SiNWs were observed for continuously, thermally oxidized SiNWs and SiNWs with smaller diameters formed at lower temperature. This can be interpreted by the phonon confinement effect. On the other hand, further thermal oxidation produced an upshift of the optical phonon peak. This is considered to be due to compressive stress since this stress was relieved by removing the surface oxide layers formed around the SiNW cores, resulting in a downshift of the optical phonon peak.
Hydrogen passivation effect on the enhancement of photoluminescence (PL) of Er ions in SiO2 films contained Si nanocrystallites (nc-Si) has been investigated. Er-doped SiO2 films were fabricated by laser ablation of Er-deposited Si substrate in oxygen gas atmosphere. The PL intensity of Er ions and nc-Si were increased by hydrogen gas treatments, while ESR signal intensity of residual defects located at the interfaces between nc-Si and SiO2 was decreased. These results indicate that hydrogen passivation of residual defects is useful for the enhancement of the Er PL.
We fabricated melt-processed (Sm0.33Eu0.33Gd0.33)Ba2Cu3Oy superconductors with fine Gd2BaCuO5 (Gd-211) particles and studied microstructure and magnetic properties as a function of the Gd-211 content and the initial particle size. Microstructure observation by scanning electron microscopy and transmission electron microscopy confirmed the presence of submicron secondary-phase particles and nanometer-sized RE1+xBa2-xCu3Oy (x ≫ 0) clusters. At 77 K, the critical current densities of 107 and 83 kA/cm2 were achieved at 0 T (self-field) and 2.2 T, respectively (superconducting quantum interference device data).
The interaction process between fast heavy ions and dense plasma
was experimentally investigated. We injected 4.3-MeV/u or
6.0-MeV/u iron ions into a z-pinch-discharge helium
plasma and measured the energy loss of the ions by the time
of flight method. The energy loss of 4.3-MeV/u ions fairly
agreed with theoretical prediction when the electron density
of the target was on the order of 1018 cm−3.
With increasing electron density beyond 1019
cm−3, the difference between the experiment
and the theory became remarkable; the experimental energy loss
was 15% larger than the theoretical value at the peak density.
For 6.0-MeV/u ions, the deviation from the theory appeared
even at densities below 1019 cm−3.
These discrepancies indicated that density effects such as ladderlike
ionization caused the enhancement of the projectile mean charge in the
target.
Microstructure of (Nd, Eu, Gd)Ba2Cu3O7−δ (NEG-123) samples with (Nd, Eu, Gd)2BaCuO5 (NEG-211) particles were observed by transmission electron microscopy. High-resolution electron microscopy observation demonstrated that the density of microstructural defects was small around the NEG-211 secondary phase particles. Furthermore, the 123/211 interfaces were found to be very clean and sharp. Chemical compositional analysis of the submicron secondary phase particles revealed that these fine particles are not composed of NEG-211 but Eu2BaCuO5 (Eu-211) or Gd2BaCuO5 (Gd-211).
Hebeloma radicosoides sp. nov. is described, illustrated and characterised. It superficially resembles H. radicosum in having a long-rooting stipe with a well-formed, membranous annulus and in having preference for animal wastes as its resources. Its pileus is
yellower than that of H. radicosum, and it fruits after addition of urea to soil, whereas H. radicosum does not. It also fruits on various
animal wastes whereas H. radicosum specifically fruits on mole or mouse middens. Unlike H. radicosum, H. radicosoides has no distinct
odour. Hebeloma radicosoides also resembles Hebeloma luchuense and H. spoliatum in having a long-rooting stipe and in fruiting on
urea-treated soil, but differs from them by having a yellowish scaly pileus and distinct, membranous annulus.
Molecular variants of individual components of the renin-angiotensin system are thought to
contribute to inherited predisposition towards essential hypertension. Using polymerase chain
reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and sequence analysis, we identified
seven polymorphisms in the 5′-flanking region of the angiotensin II
type 1 receptor (AGTR1/AT1)
gene. We conducted a case-control study in a sample from the Japanese population to determine
whether polymorphic markers in the 5′-flanking region of the AT1gene were associated with essential
hypertension. The study compared 149 hypertensive subjects to 156 normotensive control subjects.
A significantly higher frequency of the AT1(−535)*T allele was observed in hypertensive subjects.
Evidence was obtained that the AT1(−535)*T allele showed a synergistic effect on risk of
hypertension with angiotensin I converting enzyme D allele (ACE*D).