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991.
Starting from microscopic mechanics, we derive thermodynamic relations for heat conducting nonequilibrium steady states. The extended Clausius relation enables one to experimentally determine nonequilibrium entropy to the second order in the heat current. The associated Shannon-like microscopic expression of the entropy is suggestive. When the heat current is fixed, the extended Gibbs relation provides a unified treatment of thermodynamic forces in the linear nonequilibrium regime. 相似文献
992.
H. Nakagawa 《Applied Surface Science》2008,254(20):6648-6652
To compare the annealing effects on GaMnAs-doped with Zn (GaMnAs:Zn) and undoped GaMnAs (u-GaMnAs) epilayers, we grew GaMnAs thin films at 200 °C by molecular beam epitaxy (MBE) on GaAs substrates, and they were annealed at temperatures ranging from 220 °C to 380 °C for 100 min in air. These epilayers were characterized by high-resolution X-ray diffraction (XRD), electrical, and magnetic measurements. A maximum resistivity at temperatures Tm close to the Curie temperatures Tc was observed from the measurement of the temperature-dependent resistivity ρ(T) for both the GaMnAs:Zn and the u-GaMnAs samples. We found, however, that the maximum temperature Tm observed for GaMnAs:Zn epilayers increased with increasing annealing temperature, which was different from the result with the u-GaMnAs epilayers. The formation of GaAs:Zn and MnAs or Mn-Zn-As complexes with increasing annealing temperature is most likely responsible for the differences in appearance. 相似文献
993.
Takashi Imamura Yumi Iida Kinichi Obi Ikue Nagatani Kazumichi Nakagawa Iulia Patroescu‐Klotz Shiro Hatakeyama 《国际化学动力学杂志》2004,36(7):379-385
The relative‐rate method has been used to determine the rate coefficients for the reactions of OH radicals with three C5 biogenic alcohols, 2‐methyl‐3‐buten‐2‐ol (k1), 3‐methyl‐3‐buten‐1‐ol (k2), and 3‐methyl‐2‐buten‐1‐ol (k3), in the gas phase. OH radicals were produced by the photolysis of CH3ONO in the presence of NO. Di‐n‐butyl ether and propene were used as the reference compounds. The absolute rate coefficients obtained with the two reference compounds agreed well with each other. The O3 and O‐atom reactions with the target alcohols were confirmed to have a negligible contribution to their total losses by using two kinds of light sources with different relative rates of CH3ONO and NO2 photolysis. The absolute rate coefficients were obtained as the weighted mean values for the two reference compound systems and were k1 = (6.6 ± 0.5) × 10?11, k2 = (9.7 ± 0.7) × 10?11, and k3 = (1.5 ± 0.1) × 10?10 cm3 molecule?1 s?1 at 298 ± 2 K and 760 torr of air. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 379–385 2004 相似文献
994.
995.
WDM-Pulse-position modulation technique in SI-POF transmission is proposed to overcome the limitation from mode dispersion. It can expand the flat transmission bandwidth to 80MHz with 100m-fiber length. 相似文献
996.
Novel series of liquid crystalline compounds having an enyne unit, 1-(4-alkylphenyl)-4-(trans-4-alkylcyclohexyl)-but-3-en-1-yne and 1-(4-alkoxyphenyl)-4-(trans-4-alkylcyclohexyl)-but-3-en-1-yne are presented. The synthetic methods, mesomorphic phases, and some physical properties of these series are reported. 相似文献
997.
998.
H. Ohnuma K. Amos I. Morrison H. Orihara S. Nishihara T. Nakagawa K. Maeda 《Physics letters. [Part B]》1982,112(3):206-210
The angular distribution for the 16O(p, n) 16F (6.41 MeV) reaction at 35 MeV has been measured and analyzed using a distored-wave approximation. With analyses of 99 and 135 MeV data fixing the characteristics of the nuclear structure and direct reaction models required, analysis of the 35 MeV data reveals evidence of higher-order reaction processes, which we suggest involve virtual excitation of giant multipole resonances. 相似文献
999.
1000.
Solvent shifts of a series of alkanes have been studied in perfluorohexane, carbon tetrachloride and diiodomethane. The methylene proton resonances for longer alkyl chains are shifted downfield in perfluorohexane, but upfield in diiodomethane. It is suggested that n-alkanes have a tendency to adopt folded structures in solution, the degree of folding for n-alkane chains in perfluorohexane being larger than that in diiodomethane. 相似文献