[en] The stable water isotopes (SWIs) (δ18O and δD) are used as an indicator of the intensity of the atmospheric hydrological cycle due to their large variability in time and space. Although data about vapor isotope ratio with high frequency and high resolution are now available by satellite observations and spectroscopic analyses, there is some room for discussion on the variability of isotope ratios in vapor and precipitation related to cloud microphysical processes. Here, we incorporated SWI tracer into the latest version of a global cloud system resolving model (the Nonhydrostatic Icosahedral Atmospheric Model (NICAM)), iso-NICAM, and investigated the contribution of cloud microphysical processes to the variability of isotope ratios in precipitation and vapor. One of the merits used NICAM is that its physical process can cover from low spatial resolution to high spatial resolution. We conducted two mode simulations (GCM and CRM). The GCM mode simulation is based on the Arakawa-Schubert scheme as convective parameterization and a large-scale condensation scheme as the cloud physical process. In contrast, the CRM mode simulation is based on the a single-moment bulk cloud microphysics scheme with 6 water categories as cloud microphysical scheme, convective parameterization scheme was not used. These simulations are set to about 223 km of horizontal mesh resolution and 78 vertical layers. We conducted an AMIP-type climate experiment for one year from 1979. The simulated precipitation δ18O showed the latitude effect pattern (high δ18O in low latitude region, low δ18O in high latitude region), but those values in the CRM mode was slightly lower than that in the GCM mode . The simulated precipitation δ18O in the CRM mode was lower in high altitude or inland regions compared with those in the GCM mode . Besides, the precipitation d-excess in the CRM mode shows large spatial variability compared with the GCM mode. Although the low spatial resolution was set in this study, these simulations indicated cloud microphysical processes are important for understanding the variability of isotope physics. We will conduct these simulations with finer spatial resolution and a more extended simulation period.

[en] We have measured the high-field magnetization of Yb_1-xR_xInCu₄ (R=Y, La, Ce) compounds up to 53 T in the temperature range 1.5-100 K using high-quality samples. The compounds undergo a sharp first-order valence transition from the intermediate-valent state to the trivalent state with increasing either temperature or magnetic field. Both the critical temperature and the magnetic field of the transition, T_v and B_v, increase by La or Ce substitution for Yb and decrease by Y substitution. We found that the relation between B_v(T)/B_v(0) and T/T_v is given by [B_v(T)/B_v(0)]ⁿ+[T/T_v]ⁿ=1 with 2.5≤n≤3, which is inconsistent with the elliptic relation [B_v(T)/B_v(0)]²+[T/T_v]²=1 reported previously. Possible reasons for the observed contradiction are discussed based on the percolation effect

[en] The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident released the largest quantity of radiocaesium into the terrestrial environment since the Chernobyl nuclear accident. The surrounding land received 2.7 PBq of radiocaesium to forests, agricultural lands, grasslands, and urban areas, from which the radionuclides migrated through soil and waterways. In this presentation, the deposition and distribution of radionuclides, especially radiocaesium, in the terrestrial environment as a result of the FDNPP accident are discussed based on the past 10 years' intensive dataset. Anthropogenic activities such as rice and vegetable cultivation and residential activities in the upstream area have led to a rapid decline in the activity concertation of 137Cs of suspended sediment (SS) transport in the river network, and these declines directly control the dissolved 137Cs concentration in the river water. We outline the environmental and anthropogenic factors that influenced the subsequent transport and impacts of radionuclides through the environment. The environmental aftermath of the accident at Fukushima is compared to Chernobyl, and the relatively rapid remediation of the Fukushima region relative to the region surrounding Chernobyl will be explained.

[en] By the combination of heat treatment in flowing (99.8% N₂ + O.2% O₂) gas and in flowing H₂ gas, the authors have succeeded in synthesizing Bi₂Sr₂CaCu₂O_y having the stoichiometric cation composition with the highest T_c of 96 K among the Bi2212 related compounds prepared so far. The oxygen content y was measured to be 9.72 by the method of coulometric titration. Alternating current magnetic susceptibility measurements for powdered samples revealed that the superconducting transition of this Bi2212 phase is rather sharp and the Meissner volume fraction is comparable with YBa₂Cu₃O₇

[en] The high-field magnetization curves of single-crystalline YbInCu₄ have been measured along the main crystallographic axes at ambient pressure. Appreciable anisotropy has been found in the magnetization value and in the critical field of the valence transition. We have calculated the magnetization curve and the magnetic phase diagram in the B-T plane using a model of the phase transition between the free Yb³⁺ paramagnetic state in a cubic crystal electric field and the low-temperature state with a constant free energy. The calculated results agree well with the experimental data of the high-field magnetization curve. Moreover, we have measured the low-field magnetization process of Yb_0.8Y_0.2InCu₄ at low temperature under high pressure and observed an anisotropic ferromagnetic-ordering

[en] We present an experimental evidence for systematics to show the bond-angle dependence of the supertransferred hyperfine interaction and of the superexchange interaction in Cu-O-Cu bonds with the bond-angle ranging from 98 deg. to 180 deg

[en] To raise Curie temperature (T_C) for Gd, we have prepared Gd thin films by controlling deposition conditions. With raising substrate temperature (T_S) during deposition, the crystallinity was improved remarkably. The volume per Gd atom compressed rapidly with raising T_S up to 400 deg. C and then slightly expanded above this temperature. The former compression is due to progress of crystallization with increase in T_S, while the latter slight expansion is due to synthesis of interstitial alloy by capturing H₂ in residual atmosphere. The T_C increased with raising T_S, although the temperature did not rise by further injection of hydrogen atoms into Gd. Especially, the T_C for the film with T_S=600 deg. C was 292.5±0.5 K. We speculate that the increase in T_C is caused by the combination with contribution of high crystallinity and expansion of volume by synthesis of interstitial alloy

[en] Critical power characteristics of tight lattice rod assembly was investigated using a simple-shaped experimental apparatus. An electrically heated rod with four spacers was placed in a circular tube, and boiling transition condition for a rod in an annular geometry was clarified varing annulus clearance. It was found that critical heat flux depends strongly on the clearance accoding as the gap becomes smaller. This results was compared with KfK correlation and the trends were well correlated. (author)

[en] Precipitation isotopes variability is dominantly controlled by large-scale atmospheric moisture transport processes. It was argued by Yoshimura et al. with the Rayleigh-type isotope circulation model with the model reproduction of daily H₂¹⁸O variability over the sub-tropics, particularly Thailand, and monthly averages at global scales with GNIP (Global Network of Isotopes in Precipitation). However, there remain some discrepancies between the observation and the simulations. It probably implies that we cannot neglect some effect of land surface processes on the variability of precipitation isotopes; in particular. The effect on diurnal variaitons on precipitation seems quite large. To take a deeper insight on short-term variability of recipitation isotopes, including diurnal variability, the authors developed an isotope-incorporated land surface model coupled with the existed atmospheric isotope circulation model

[en] The impact of freeze-thaw processes and subsequent runoff affecting the 137Cs flux and concentration in sediment discharge were revealed in bareland erosion plot following the Fukushima nuclear power plant accident by detailed monitoring and laser scanner measurement on the soil surface. We found that surface topographic changes due to the frost-heaving during the winter-spring period, and rill formation during the summer. We also found the evident seasonal changes in 137Cs concentration; high during the early spring and gradually decreased thereafter, then surface runoff from the plot frequently occurred during spring and autumn when rainfall was high and reached a maximum in summer. From these results, the higher 137Cs concentration in spring was caused by a mixture of unstable surface sediment following freeze-thaw processes and then transported in the early spring, but erosion amount is not significant because of the less rainfall event. The sediment with a lower 137Cs concentration, which was supplied from the rill erosion and its expansion, was wash-offed during the summer, contributing most of the flux from erosion in bareland in Fukushima region. In case, heavy rainfall occurs in the early spring, caution is required because high concentrations of cesium may flow down into the river.