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121.
Nakai M Funabiki T Ohtsuki C Harada M Ichimura A Tanaka R Kinoshita I Mikuriya M Benten H Ohkita H Ito S Obata M Yano S 《Inorganic chemistry》2006,45(7):3048-3056
Two new dinuclear Ru(III) complexes containing naphthalene moieties, K[Ru2(dhpta)(mu-O2CCH2-1-naph)2] (1) and K[Ru2(dhpta)(mu-O2CCH2-2-naph)2] (2) (H5dhpta = 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid, naph-1-CH2CO2H = 1-naphthylacetic acid, naph-2-CH2CO2H = 2-naphthylacetic acid), were synthesized. Complex 2 crystallized as an orthorhombic system having a space group of Pbca with unit cell parameters a = 10.6200(5) A, b = 20.270(1) A, c = 35.530(2) A, and Z = 8. EXAFS analysis of 1 and 2 in the solid states and in solution clarified that the dinuclear structures of 1 and 2 were kept in DMSO solutions. Variable-temperature magnetic susceptibility data indicated that the two Ru(III) centers are strongly antiferromagnetically coupled as shown by the large coupling constants, J = -581 cm(-1) (1) and -378 cm(-1) (2). In the cyclic voltammograms of 1 and 2, one oxidation peak and two reduction peaks which were assigned to the redox reaction of the ruthenium moieties were observed in DMF. The large conproportionation constants estimated from the reduction potentials of Ru(III)Ru(III) and Ru(III)Ru(II) indicated the great stability of the mixed-valent state. The mixed-valent species [Ru(III)Ru(II)(dhpta)(mu-O2CCH2-R)2](2-) (R = 1-naph (6) and R = 2-naph (7)) were prepared by controlled potential electrolysis of 1 and 2 in DMF. The electronic absorption spectra of 6 and 7 were similar to that of [Ru(III)Ru(II) (dhpta)(mu-O2CCH3)2](2-) which is a typical Class II type mixed-valent complex. The fluorescence decay of 1 and 2 indicated that there are two quenching processes which come from the excimer and monomer states. The short excimer lifetimes of 1 and 2 were ascribed to the energy transfer from the naphthyl moieties to the Ru centers. The different excimer ratio between 1 and 2 suggested that the excimer formation is affected by the conformation of the naphthyl moieties in the diruthenium(III) complexes. 相似文献
122.
Novel morphology titanate tubes were successfully synthesized via a self-assembly and self-removal process. After the product was treated by calcinating and washing, crystalline TiO2 tubes were obtained. In this study, two new concepts are applied to design the synthetic route: (i) titanium glycolate rods obtained from an ethylene glycol-mediated process and titanate sheets synthesized using the hydrothermal process were used as the template and the precursor, respectively, and ii) the template was directly removed in the reaction without posttreatment. Furthermore, a possible mechanism was proposed for the formation of tubular structures. 相似文献
123.
Kitamura T Takemoto H Adachi S Mokhtari P Honda K 《The Journal of the Acoustical Society of America》2006,120(4):2239-2249
Acoustic effects of the time-varying glottal area due to vocal fold vibration on the laryngeal cavity resonance were investigated based on vocal tract area functions and acoustic analysis. The laryngeal cavity consists of the vestibular and ventricular parts of the larynx, and gives rise to a regional acoustic resonance within the vocal tract, with this resonance imparting an extra formant to the vocal tract resonance pattern. Vocal tract transfer functions of the five Japanese vowels uttered by three male subjects were calculated under open- and closed-glottis conditions. The results revealed that the resonance appears at the frequency region from 3.0 to 3.7 kHz when the glottis is closed and disappears when it is open. Real spectra estimated from open- and closed-glottis periods of vowel sounds also showed the on-off pattern of the resonance within a pitch period. Furthermore, a time-domain acoustic analysis of vowels indicated that the resonance component could be observed as a pitch-synchronized rise-and-fall pattern of the bandpass amplitude. The cyclic nature of the resonance can be explained as the laryngeal cavity acting as a closed tube that generates the resonance during a closed-glottis period, but damps the resonance off during an open-glottis period. 相似文献
124.
Osaka T Matsunaga T Nakanishi T Arakaki A Niwa D Iida H 《Analytical and bioanalytical chemistry》2006,384(3):593-600
Magnetic nanoparticles have been attracting much interest as a labeling material in the fields of advanced biological and
medical applications such as drug delivery, magnetic resonance imaging, and array-based assaying. In this review, synthesis
of iron oxide magnetic nanoparticles via a reverse micelle system and modification of their surface by an organosilane agent
are discussed. Furthermore, as a practical biological assay system, the magnetic detection of biomolecular interactions is
demonstrated by using the combination of a patterned substrate modified with a self-assembled monolayer and the magnetic nanoparticles. 相似文献
125.
Yoshiyuki?Kimura Hironori?OyaEmail authorView authors OrcID profile 《Algebras and Representation Theory》2018,21(3):589-604
In this paper, we show that quantum twist maps, introduced by Lenagan-Yakimov, induce bijections between dual canonical bases of quantum nilpotent subalgebras. As a corollary, we show the unitriangular property between dual canonical bases and Poincaré-Birkhoff-Witt type bases under the “reverse” lexicographic order. We also show that quantum twist maps induce bijections between certain unipotent quantum minors. 相似文献
126.
E. Dureuil H. Nagaoka T. Futagami H. Obata L. Amy F. Pregl W. Gerlach E. Schweitzer und O. Schumm 《Fresenius' Journal of Analytical Chemistry》1929,77(3-4):130-133
Ohne Zusammenfassung 相似文献
127.
128.
Takahiro Kumamaru Yasuaki Okamoto Manabu Yamamoto Yoichi Obata Kazuki Onizuka 《Analytica chimica acta》1990
A high preconcentration method for the determination of cobalt by graphie furnace atomic absorption spectrometry using liquid surfactant membranes was developed. Droplets of dilute hydrochloric acid in kerosene containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester emulsion coated with sorbitan monooleate are dispersed in an aqueous sample solution. Cobalt(II) diffuses through the liquid membrane to form the complex with the ester and the analyte ion is extracted successively into the inner acidic aqueous phase. A 550-fold enrichment of cobalt(II) and a detection limit of 10 pg ml?1 are achieved. 相似文献
129.
Influence of pyrimidine additives in electrolytic solution on dye-sensitized solar cell performance 总被引:4,自引:0,他引:4
Hitoshi Kusama Hironori Arakawa 《Journal of photochemistry and photobiology. A, Chemistry》2003,160(3):171-179
The influence of pyrimidine additives on the performance of a bis(tetrabutylammonium)cis-bis(thiocyanato)bis(2,2′-bipyridine-4-carboxylic acid, 4′-carboxylate)ruthenium(II) dye-sensitized TiO2 solar cell with an I−/I3− redox electrolyte in acetonitrile was studied. The current–voltage characteristics were measured for more than 10 different pyrimidine derivatives under AM 1.5 (100 mW/cm2). The pyrimidine additives tested had varying effects on the performance of the cell. The additives drastically enhanced the open-circuit photovoltage (Voc) and the solar energy conversion efficiency (η), but usually reduced the short circuit photocurrent density (Jsc) of the solar cell. Physical and chemical properties of the pyrimidines were computationally calculated in order to determine the reasons for the additive effects on cell performance. Consequently, the greater the calculated partial charge of the nitrogen atoms in the pyrimidine groups, the larger the Voc but the smaller the Jsc values. The Voc of the cell also increased as the ionization energy of the pyrimidine molecules decreased. Moreover, as the calculated dipole moment of the pyrimidine derivatives increased, the Jsc value was reduced, but the Voc value was enhanced. These results suggest that the electron donicity of pyrimidine additives influenced the interaction with TiO2 electrode and I−/I3− electrolyte, which lead to the changes in dye-sensitized solar cell performance. 相似文献
130.
Hiroko Obata Shigeo Ogawa 《Journal of polymer science. Part A, Polymer chemistry》1969,7(6):1415-1424
In order to study the thermal stabilities of the α-helical polyamino acids in the solid state, measurements of the infrared spectra at high temperature, weight loss by thermogravimetry, and the expansion of the α-helix by x-ray diffractometry were carried out on poly(γ-methyl D -glutamate), poly(γ-benzyl L -glutamate), poly-L -alanine, poly(β-benzyl L -aspartate), poly-δ-carbobenzoxy-L -ornithine and poly-ε-carbobenzoxy-L -lysine. The thermal degradation temperatures of these polymers lie between 140°C and 230°C. The α-helical conformation is stable at high temperature in these polyamino acids, except for poly(β-benzyl L -asparatate), unless thermal degradation takes place. As temperature rises, the amide A and the amide I bands of the infrared spectra shift slightly to higher frequencies and the amide II band to lower frequencies. At the same time, the intensities of these amide bands decrease. These changes differ among the different molecules. From the x-ray measurement, it was found that the α-helix expands along the helical axis with temperature. It is expected that the intramolecular hydrogen bonds of the α-helix become weak with increasing temperature and that the state of the hydrogen bonds of the α-helices depends upon the molecules. 相似文献