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41.
42.
Gururaj M. ShivashimpiShyam S. Pandey Rie WatanabeNaotaka Fujikawa Yuhei OgomiYoshihiro Yamaguchi Shuzi Hayase 《Tetrahedron letters》2012,53(40):5437-5440
Aiming toward the development of far-red sensitive organic dyes, unsymmetrical squaraine dye bearing direct cyanoacrylate functionalized indole ring has been synthesized and characterized along with its utilization as photosensitizer for dye-sensitized solar cells. Upon dye-sensitized solar cell fabrication, this sensitizer exhibits its potentiality as a good far-red sensitive dye having photoconversion efficiency of 5.03% under the simulated solar irradiation at AM 1.5 conditions. This opens up further possibility to design efficient far-red sensitive dyes by judicious implementation of suitable donor moieties with extended π-conjugation. 相似文献
43.
Through the analyses on the irreversibility lines (ILLs) under H||c for various high-Tc superconducting (HTSC) single-crystalline samples, we found two universal functions representing ILLs. In these functions, the electromagnetic anisotropy factor γ2 plays a crucial role. The appropriate chemical substitution, such as Bi(Pb)2212, is an effective method to improve flux pinning properties via decreasing γ2. 相似文献
44.
S. Horii M. Yamaki H. Ogino T. Maeda J. Shimoyama 《Physica C: Superconductivity and its Applications》2010,470(20):1056-1059
We report the grain-orientation effects under a modulated rotation magnetic field for Y-based cuprate superconductors and LaFeAsO (La1111). Tri-axial orientation has been successfully achieved only for orthorhombic Y2Ba4Cu7Oy and YBa2Cu4O8 powders without a twin microstructure, while separation of three crystallographic axes could not be observed in twinned YBa2Cu3Oy (Y123) and tetragonal La1111 powders. The morphology of grains, in addition to the symmetry of crystal structures, seriously affects the degrees of tri-axial orientation, which means that the control of twin microstructures is required for the tri-axial magnetic orientation in Y123. 相似文献
45.
The solubilities and selectivities for CO2, N2 and CH4 in ionic liquid were predicted using a COSMO based activity coefficient model, COSMO-SAC method. The 1-alkyl-3-methylimidazolium cations were focused in this work. The anion species include tetrafluoroborate [BF4], hexafluorophosphate [PF6], triflate [OTf], dicyanamide [dca] and bis(trifluoromethane)-sulfonimide [Tf2N]. The predicted results of the solubilities of CO2 in the ionic liquids by COSMO-SAC method are in agreement with the experimental data within the averaged deviation of 0.0017 in mole fraction. The predicted results of selectivities for CO2/N2 and CO2/CH4 represent the effects of anion species qualitatively. Permeability through supported liquid membrane can be presented by solubility and diffusion coefficients in the liquid. The permeabilities of CO2 through the ionic liquid membranes were also predicted by a solution-diffusion model with COSMO-SAC method. The predicted results of the CO2 permeabilities through the ionic liquids represent the experimental data within the order of the permeabilities. 相似文献
46.
Masahiro Kikuchi Mohammad S. Hussain Norio Morishita Mitsuko Ukai Yasuhiko Kobayashi Yuhei Shimoyama 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2010,75(1):310-313
An electron spin resonance (ESR) spectroscopic study of radicals induced in irradiated fresh mangoes was performed. Mangoes in the fresh state were irradiated with γ-rays, lyophilized and then crushed into a powder. The ESR spectrum of the powder showed a strong main peak at g = 2.004 and a pair of peaks centered at the main peak. The main peak was detected from both flesh and skin specimens. This peak height gradually decreased during storage following irradiation. On the other hand, the side peaks showed a well-defined dose–response relationship even at 9 days post-irradiation. The side peaks therefore provide a useful means to define the irradiation of fresh mangoes. 相似文献
47.
Shimoyama Y Ukai M Nakamura H 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,63(4):888-890
We revealed free radicals in wheat flour before and after gamma-ray irradiation and their thermal behavior during heat-treatment using electron spin resonance (ESR) spectroscopy. The ESR spectrum of wheat flour before irradiation consists of a sextet centered at g = 2.0 and a singlet signal at the same g-value position. The first one is attributable to a signal with hyperfine (hf) interactions of Mn2+ ion (hf constant: 7.4 mT). The second is originated from carbon-centered radical. Upon gamma-ray irradiation, however, a new signal with two triplet lines at the low and high field ends was detected in wheat flour on top of the Mn2+ sextet lines. We analyzed the triplet ESR lines as powder spectra (rhombic g-tensor symmetry) with nitrogen (14N) hyperfine interactions. This indicates that a new organic radical was induced in the conjugated protein portion of wheat flour by the gamma-ray irradiation. Intensity of the organic free radical at g = 2.0 detected in irradiated wheat flour increased monotonically by the thermal treatment. The analysis of the time-dependent evolution and decay process based on the theory of transient phenomena as well as the nonlinear least-squares numerical method provided a unique time constant for the radical evolution and decay in wheat flour during the heat-treatment. 相似文献
48.
Ukai M Nakamura H Shimoyama Y 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,63(4):879-882
We found various free radicals in a commercially available pepper in Japan before and after irradiation using electron spin resonance (ESR) spectroscopy. The typical ESR spectrum of the pepper consists of a sextet centered at g = 2.0, a singlet at the same g-value and a singlet at g = 4.0. Upon gamma ray irradiation, a new pair of signals appeared in the pepper. The progressive saturation behavior (PSB) at various microwave power levels indicated quite different relaxation behaviors of those radicals. Namely, the peak intensity of the organic free radical component decreases in a monotonic fashion, whereas the Mn2+ and Fe3+ ESR signals substantially keep constant. This reflects the evidence of three independent radicals in the pepper before irradiation. The PSB of the pair peaks as induced by irradiation possessed quite different PSB from that of the free radical located at g = 2.0. We proposed a new protocol for the ESR detection of irradiated foods by the PSB method at different microwave power levels. This would call for a major modification of the CEN protocol in European Union. 相似文献
49.
Maeda Y Kanda M Hashimoto M Hasegawa T Kimura S Lian Y Wakahara T Akasaka T Kazaoui S Minami N Okazaki T Hayamizu Y Hata K Lu J Nagase S 《Journal of the American Chemical Society》2006,128(37):12239-12242
The dispersion of small-diameter single-walled carbon nanotubes (SWNTs) produced by the CoMoCAT method in tetrahydrofuran (THF) with the use of amine was studied. The absorption, photoluminescence, and Raman spectroscopies showed that the dispersion and centrifugation process leads to an effective separation of metallic SWNTs from semiconducting SWNTs. Since this method is simple and convenient, it is highly applicable to an industrial utilization for widespread applications of SWNTs. 相似文献
50.
Futaba DN Hata K Namai T Yamada T Mizuno K Hayamizu Y Yumura M Iijima S 《The journal of physical chemistry. B》2006,110(15):8035-8038
We propose a statistical and macroscopic analysis to estimate the catalyst activity of water-assisted growth (super-growth) of single-walled nanotubes (SWNT) and to characterize SWNT forests. The catalyst activity was estimated to be 84% (+/-6%), the highest ever reported. The SWNT forest was found to be a very sparse material where SWNTs represent only 3.6% of the total volume. This structural sparseness is believed to play a critical role in achieving highly efficient growth. 相似文献