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991.
Satoshi Yamaguchi Yuki Miyoshi Yuka Watanabe-Ezoe Tomoko Imasaka 《Analytica chimica acta》2009,632(2):229-928
Gas chromatography/multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOF-MS) was applied to the trace analysis of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). To determine the optimum wavelength for analysis of PCDD/Fs, the wavelength of the femtosecond laser utilized for multiphoton ionization was converted to near-ultraviolet status using stimulated Raman scattering. A femtosecond laser emitting at 300 nm completely eliminated the background signal arising from the bleeding compounds generated from a stationary phase of the capillary column in GC. 相似文献
992.
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995.
Rusydi A Abbamonte P Eisaki H Fujimaki Y Blumberg G Uchida S Sawatzky GA 《Physical review letters》2006,97(1):016403
We have used resonant soft x-ray scattering to study the effects of discommensuration on the hole Wigner crystal (HC) in the spin ladder Sr(14-x)CaxCu24O41 (SCCO). As the hole density is varied the HC forms only with the commensurate wave vectors L(L) = 1/5 and L(L) = 1/3; for incommensurate values it "melts." A simple scaling between L(L) and temperature is observed, tau1/3/tau1/5 = 5/3, indicating an inverse relationship between the interaction strength and wavelength. Our results suggest that SCCO contains hole pairs that are crystallized through an interplay between lattice commensuration and Coulomb repulsion, reminiscent of the "pair density wave" scenario. 相似文献
996.
Charge dynamics of (Ti1-xVx)2O3 with x=0-0.06 has been investigated by measurements of charge transport and optical conductivity spectra in a wide temperature range of 2-600 K with the focus on the thermally and doping induced insulator-metal transitions (IMTs). The optical conductivity peaks for the interband transitions in the 3d t_{2g} manifold are observed in both the insulating and metallic states, while their large variation (by approximately 0.4 eV) with change of temperature and doping level scales with that of the Ti-Ti dimer bond length, indicating the weakened singlet bond in the course of IMTs. The thermally and V-doping induced IMTs are driven with the increase in carrier density by band crossing and hold doping, respectively, in contrast with the canonical IMT of correlated oxides accompanied by the whole collapse of the Mott gap. 相似文献
997.
Atsushi Kubo Yanbin Wang Takeyuki Uchida Norimasa Nishiyama Thomas S. Duffy 《Journal of Physics and Chemistry of Solids》2008,69(9):2255-2260
The melting curve of silicon has been determined up to 15 GPa using a miniaturized Kawai-type apparatus with second-stage cubic anvils made of X-ray transparent sintered diamond. Our results are in good agreement with the melting curve determined by electrical resistivity measurements [V.V. Brazhkin, A.G. Lyapin, S.V. Popova, R.N. Voloshin, Nonequilibrium phase transitions and amorphization in Si, Si/GaAs, Ge, and Ge/GaSb at the decompression of high-pressure phases, Phys. Rev. B 51 (1995) 7549] up to the phase I (diamond structure)—phase II (β-tin structure)—liquid triple point. The triple point of phase XI (orthorhombic, Imma)—phase V (simple hexagonal)—liquid has been constrained to be at 14.4(4) GPa and 1010(5) K. These results demonstrate that the combination of X-ray transparent anvils and monochromatic diffraction with area detectors offers a reliable technique to detect melting at high pressures in the multianvil press. 相似文献
998.
In this study, we analyze the network effect in a model of a personal communication market, by using a multi-agent based simulation approach. We introduce into the simulation model complex network structures as the interaction patterns of agents. With complex network models, we investigate the dynamics of a market in which two providers are competing. We also examine the structure of networks that affect the complex behavior of the market. By a series of simulations, we show that the structural properties of complex networks, such as the clustering coefficient and degree correlation, have a major influence on the dynamics of the market. We find that the network effect is increased if the interaction pattern of agents is characterized by a high clustering coefficient, or a positive degree correlation. We also discuss a suitable model of the interaction pattern for reproducing market dynamics in the real world, by performing simulations using real data of a social network. 相似文献
999.
Y. Noda S. Shimono M. Baba J. Yamauchi Y. Uchida N. Ikuma R. Tamura 《Applied magnetic resonance》2008,33(3):251-267
By electron paramagnetic resonance spectroscopy we investigated the molecular orientation in a surface-stabilized liquid crystal
(LC) cell, which includes a racemic (±) or an enantiomerically enriched (S,S) paramagnetic LC, (2S,5S)-2,5-dimethyl-2-tridecyloxyphenyl-5-[4-(4-tridecyloxy-benzenecarbonyloxy)phenyl]pyrrolidine-1-oxy (2), whose spin source is fixed inside the rigid core. For both the smectic C (SmC) phase of (±)-2 and the chiral smectic C (SmC*) phase of (S,S)-2 in a surface-stabilized LC cell (antiparallel configuration, thickness of 4 μm), the profile of the observed g-value as a function of the angle between the applied magnetic field and the cell plane could be explained by the orientation
model, where, with some disordering, the molecules align uniformly with the direction which tilts from the normal line of
the smectic layer being orthogonal to the rubbing direction on the cell surface. We divided the effect from the disordering
into two parts, one of which is concerning the direction of the molecular long axis and the other is concerning the rotation
around the molecular long axis. As a result of the analysis, the SmC* phase gave quite lower ordering concerning the direction of the molecular long axis and a little lower ordering concerning
the rotation around the molecular long axis than the SmC phase at the same temperature (80 °C). The obtained lower ordering
in the SmC* phase is probably due to the chirality that would result in the formation of a helical superstructure in a bulky state.
Authors' address: Yohei Noda, Laboratory of Electron Spin Chemistry, Department of Chemistry, Graduate School of Science,
Kyoto University, 606-8502 Kyoto, Japan 相似文献
1000.
Shigeyuki Ishida Masamichi Nakajima Hijiri Kito Yasuhide Tomioka Toshimitsu Ito Akira Iyo Hiroshi Eisaki Shin-ichi Uchida 《Physica C: Superconductivity and its Applications》2009,469(15-20):905-907
Transport properties of BaNi2P2 single crystals prepared by high-pressure synthesis method have been investigated. The temperature dependence of the resistivity is that of a typical metal with the anisotropy ratio ρ/ρ of 6.3 and suggests that electron–phonon interaction dominates the scattering mechanism. We have also found that the Hall effect and the magnetoresistance can be explained by a two-carrier model which is consistent with a multiple-band structure with both hole and electron characters. 相似文献