[en] A scheduling support system through knowledge-based man-machine cooperation has been developed for nuclear power plant construction. The proposed system, named NPCS, has three characteristic functions: (1) Automatic dissolution of constraint violations using a constraint-oriented programming technique; (2) Automatic resource leveling based on a combinatorial-optimization technique using heuristic rules on task ordering; (3) Display of a scheduling chart which facilitates interactive schedule modification performed by expert engineers. A scheduling process of NPCS consists of two steps. At the first steps, an initial schedule with leveled resource is built, and at the second step, the initial schedule is improved interactively, where constraint violations are dissolved automatically. NPCS was experimentally applied to solve about 80 scheduling problems in a nuclear power plant construction and confirmed to reduce the scheduling time and to improve the quality of the schedule. (author)

[en] In this study, we show a synthesis of λ-Ti_3O_5 nanocrystals dispersed in silica by sol–gel method. The X-ray diffraction measurements, Rietveld analyses, and transmission electron microscope images of the obtained samples showed that tuning the sintering temperature in the synthesis process can control the size of the λ-Ti_3O_5 nanocrystals, i.e., 8±2 nm (1123°C; sample 1), 9±3 nm (1133°C; 2), 9±2 nm (1143°C; 3), 10±3 nm (1153°C; 4), 11±4 nm (1163°C; 5), 13±4 nm (1173°C; 6), 25±12 nm (1200°C; 7), and 36±15 nm (1250°C; 8), whereas adjusting the hydrogen flow rate can tune the oxidation-reduction state of the sample without apparent change in the crystal size. At the lowest sintering temperature of 1123°C, the smallest X-Ti_3O_5 nanocrystals of 8 nm in size were produced

[en] The photoinduced charge-transfer process in Rb_0.94Mn[Fe(CN)₆]_0.98·0.2H₂O is investigated by observing the valence states of the metal ions by Raman spectroscopy. The sample in the high-temperature phase is irradiated at the ligand to metal, CN^-→Fe(III) and charge-transfer band (λ=395 nm). The Fe(III)-CN-Mn(II) pair valence state corresponding to the high-temperature configuration is totally depleted after prolonged irradiation, and the Fe(II)-CN-Mn(III) pair valence state corresponding to the low-temperature configuration appears. In addition, two kinds of CN stretching modes, ascribed to Fe(II)-CN-Mn(II) and Fe(III)-CN-Mn(III) pair valence states, are found. The photoproduction process of each pair valence states is well reproduced by a kinetic model assuming a charge transfer from Mn(II) to Fe(III). During irradiation, continuous shifts of the Raman peaks are found and ascribed to a release of the strain due to the lattice mismatching between the high-temperature and the photoinduced phases. This behavior indicates that the photoinduced phase created locally in the high-temperature-phase lattice grows up to a photoinduced phase domain. The conversion efficiency is lowered with decreasing temperature, indicating the existence of an energy barrier. We propose a model, which can explain the existence of an energy barrier in the electronic excited state.

[en] Temperature dependence of the photoinduced charge transfer process in Rb_0.94Mn[Fe(CN)₆]_0.98·0.2H₂O was investigated by observing the pair valence states of adjacent metal ions by Raman spectroscopy. After irradiation by 395 nm light in resonance with ligand-to-metal charge transfer band (CN^- → Fe(III)), the photoinduced phase containing low-temperature-like phase was generated as a result of the charge transfer from Mn(II) to Fe(III). Since this process was suppressed upon cooling, it was suggested that the charge transfer process was assisted by a thermal-activated process.

[en] An anomalous direction of the shift of the temperature maximum of magnetic susceptibility with increasing magnetic field frequency was observed in ε-In_0_._2_4Fe_1_._7_6O_3 nanowires arrays in spite of the prediction of the theory of thermoactivated processes. The unusual effect can be explained by the redistribution of the contributions from low- and high-temperature phases to the temperature dependence of magnetic susceptibility. The magnetic state of each of the phases is described by the model of cluster magnetic glass. Separated electron spin resonance responses of these phases were distinguished.

[en] Photoinduced charge transfer dynamics in the photomagnetic material RbMn[Fe(CN)₆], which exhibits a magnetic phase transition with a large hysteresis loop (230-300 K), has been investigated by observing the CN^- stretching modes, which are sensitive to the valences of the adjacent transition metal ions. Mid-infrared transient absorption measurements were performed between 2013 and 2179 cm^-1 to observe the transient and persistent products. The sample in the high-temperature phase was excited by 400 nm laser pulses at the ligand to metal charge transfer band near the high-temperature end of the hysteresis loop. Bleach of the Fe³⁺-CN^--Mn²⁺ band representing a decrease of the high-temperature phase and increases of the Fe²⁺-CN^--Mn³⁺ and Fe²⁺-CN^--Mn²⁺ bands were observed in picosecond time region, indicating a transient production of charge transferred states.

[en] Cesium manganese hexacyanoferrate is an interesting material which exhibits the phase transition with the magnetic susceptibility variation under the effect of external stimuli; such as temperature and visible light irradiation. This phase transition attributes the charge transfer between ions in the Fe-CN-Mn bond. Recently, we observed the phase transition by X-ray irradiation below 80 K. The X-ray absorption spectrum of the low-temperature (LT) phase approached toward that of the high-temperature (HT) phase. The spectrum variation by X-ray irradiation attributes the charge transfer from Fe^II to Mn^III.

[en] Charge and lattice dynamics has been investigated for Na_0.79Co[Fe(CN)₆]_0.902.9H₂O film at 300 K by means of the time-resolved x-ray diffraction apparatus coupled with the in situ time-resolved absorption measurement. We observed an uniform lattice expansion whose relaxation time is ∼ 40 ns. Based on the close correlation between the charge and lattice dynamics, the lattice expansion is ascribed to the photo-created charge-transferred Co²⁺ - Fe³⁺ state.

[en] The charge density distribution has been determined for a transition metal cyanide, RbMn[Fe(CN)₆], by means of the maximum entropy-Rietveld method combined with the highly angularly resolved synchrotron radiation x-ray powder diffraction at SPring-8 BL02B2. We directly observed a charge transfer from the Mn site to the Fe site in the low-temperature phase. On the basis of a local density approximation calculation, we discuss the origin for the anisotropic bonding electron distribution around the Mn³⁺ ion in the low-temperature phase