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71.
Recent progress in photocatalytic decomposition of water to H2 and O2 using simple oxide semiconductor catalysts has been reviewed. Addition of Na2CO3 to Pt/TiO2 suspension in water enhanced the stoichiometric decomposition significantly. This Na2CO3 addition method has been proved to be very useful to accelerate water splitting over various kinds of oxide semiconductor photocatalysts. The role of CO3 2? anion on the acceleration of water splitting was clarified. Finally, it was firstly demonstrated in the world that water was decomposed efficiently and stoichiometrically to H2 and O2 using a 3 wt% NiOx/TiO2 photocatalyst under real solar light irradiation in Tsukuba, Japan by this Na2CO3 addition method. 相似文献
72.
Ryuji Nakao Kenji Furutsuka Masatoshi Yamaguchi Kazutoshi Suzuki 《Analytical sciences》2007,23(2):151-155
A sensitive, selective and rapid high-performance liquid chromatographic (HPLC) method with chemiluminescence (CL) detection was developed and validated for the analysis of positron emission tomography (PET) radiopharmaceuticals. This method is based on the CL reaction of PET compounds with tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy)(3)(2+)] and acidic potassium permanganate [KMnO(4)]. After optimization of the reaction conditions, 12 of the 14 PET compounds investigated could be successfully detected and showed good performance in terms of sensitivity, linearity and reproducibility. In particular, for compounds with a tertiary amine functional group, the limits of detection were ppb levels for a 20 microL injection volume. Finally, this method was used to determine PET compounds for calculating of specific radioactivity in pharmaceutical samples. 相似文献
73.
Hiroyuki Shinoda Michio Sayama Masa-Aki Mori Hiroshi Kozuka 《International journal of quantum chemistry》1993,45(1):97-104
Hydration to the aldehyde group in nitro-substituted benzaldehydes was studied theoretically by using an AM 1 method. The calculated values of activation energy and heat of reaction showed good correlations with the experimental values of rate constants and equilibrium constants, respectively. To examine the hydration mechanism, localized molecular orbitals were calculated. Furthermore, expression of the molecular orbitals of supermolecular complexes in terms of occupied and vacant orbitals of the component molecules elucidated that the interaction between the lonepair orbital of water and the antibonding C? O π-orbital of aldehyde was important. 2,6-DNBAl was concluded to be less reactive toward water than was 2.4-DNBAl. This is consistent with the experimental result that the mutagenic activity of 2,4-DNBAl depends not only on the reduction of the nitro group by a bacterial enzyme but also on the acetyl conjugation, but that in the case of 2,6-DNBAl the mutagenic activity is manifested through the reduction by a bacterial enzyme. © 1993 John Wiley & Sons, Inc. 相似文献
74.
Akinori Tanaka Yuitsu TakedaTazumi Nagasawa Kazutoshi Takahashi 《Solid State Communications》2003,126(4):191-196
We have carried out a photoemission study using synchrotron radiation of dodecanethiolate (DT)-passivated Au nanoparticles supported on the highly oriented pyrolytic graphite substrates. From detailed line-shape analyses of Au 4f core-level photoemission spectra of DT-passivated Au nanoparticles, it was found that Au 4f core-level spectra consist of two components. We attribute these components to the inner Au atoms and surface Au atoms bonded to surface dodecanethiolates. From these results, we discuss the chemical states of the present DT-passivated Au nanoparticles. 相似文献
75.
Hidemitsu Aoki Kazutoshi Ohyama Toshiaki Seino Takashi Sugino 《Applied Surface Science》2007,254(2):596-599
Boron carbon nitride (BCN) shows promise as a field emitter material because of its mechanical hardness, chemical inertness, and low electron affinity. This study investigated the modification of a BCN film with an amorphous area using KrF excimer laser (wavelength: 248 nm, photon energy: 5.0 eV) annealing without substrate heating. This achieved significant variation in characteristics, such as an increase in bandgap energy and decrease in electron affinity. Laser annealing reduced electron affinity from 0.7 to 0.3 eV. The results indicate that the modification of the BCN film by KrF excimer laser annealing achieves characteristics similar to hexagonal BN (h-BN) film without losing the desirable properties of the BCN film, such as physical stability. 相似文献
76.
77.
Kazutoshi Tanabe 《Chemical physics》1979,38(1):125-129
Line widths of isotropic Raman spectra of the ν1 (a1) CH or CD stretching bands of acetonitrile CH3CN and CD3CN were measured in a number of solvents. The vibrational dephasing theory, modified for use in binary mixtures, predicts quantitatively the solvent dependence of the Raman line widths. 相似文献
78.
Shindo K Osawa A Nakamura R Kagiyama Y Sakuda S Shizuri Y Furukawa K Misawa N 《Journal of the American Chemical Society》2004,126(46):15042-15043
The comprehensive bioconversion of aromatic compounds with a benzene ring to a picolinic acid was achieved with a recombinant Escherichia coli strain that expressed the six genes involved in biphenyl catabolism, these being the bphA1(2072)A2A3A4 genes encoding the evolved biphenyl dioxygenase, the bphB gene encoding dihydrodiol dehydrogenase, and the bphC gene encoding catechol 2,3-dioxygenase. 相似文献
79.
Aoki M Kaneko M Izumi S Ukai K Iwasawa N 《Chemical communications (Cambridge, England)》2004,(22):2568-2569
Novel bidentate amidines were designed and synthesized as easily available electron-donating N-ligands for Ni0-mediated coupling of carbon dioxide with alkynes or allenes, and high regioselectivity was achieved even for the carboxylation of aryl substituted internal alkynes. 相似文献