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11.
Soejima T Jin RH Terayama Y Takahara A Shiraishi T Ito S Kimizuka N 《Langmuir : the ACS journal of surfaces and colloids》2012,28(5):2637-2642
A far-from-equilibrium strategy is developed to synthesize coral-like nanostructures of TiO(2) on a variety of surfaces. TiO(2) nanocoral structures consist of anatase base film and rutile nanowire layers, and they are continuously formed on substrates immersed in aqueous TiOSO(4)-H(2)O(2). The sequential deposition of TiO(2) starts with hydrolysis and condensation reactions of titanium peroxocomplexes in the aqueous phase, resulting in deposition of amorphous film. The film serves as adhesive interface on which succeeding growth of rutile nanowires to occur. This initial deposition reaction is accompanied by shift in pH of the reaction media, which is favorable condition for the growth of rutile nanocrystals. During the growth of rutile nanocoral layers, the amorphous base films are transformed to anatase phase. These sequential deposition reactions occur at temperatures as low as 80 °C, and the mild synthetic condition allows the use of a wide range of substrates such as ITO (indium tin oxide), glass, and even organic polymer films. The thickness of nanocoral layer is controllable by repeating the growth reaction of rutile nanocorals. TiO(2) nanocorals show photocatalytic activity as demonstrated by site-specific reduction of Ag(I) ions, which proceeds preferentially on the rutile nanowire layer. The rutile nanowire layer also shows photocatalytic decomposition of acetaldehyde, which is promoted upon increase of the thickness of the nanowire layer. The use of temporally transforming reaction media allows the formation of biphasic TiO(2) nanocoral structures, and the concept of nonequilibrium synthetic approach would be widely applicable to developing structurally graded inorganic nanointerfaces. 相似文献
12.
Frequency-modulated stimulated Brillouin spectroscopy has been performed for high-refractive-index glasses including heavy-metal oxide glasses, chalcogenide glasses and TeO2-based and Bi2O3-based glasses. Although the Brillouin linewidth in glassy materials is broader in general than that in crystalline materials, we have found that the Brillouin linewidth of Ge33As12Se55 chalcogenide glass is considerably narrow and is comparable to that in crystals. 相似文献
13.
Masanori Utaka Seishiro Matsushita Haruhiro Yamasaki Akira Takeda 《Tetrahedron letters》1980,21(11):1063-1064
The base-catalyzed autoxidation of diosphenol was catalyzed by cationic micelles with a remarkable selectivity to give an 1,5-keto acid by a mechanism analogous to the oxygenation of quercetin or 3-hydroxyflavones. 相似文献
14.
Seishiro Nakamura 《Catalysis Surveys from Japan》1998,2(1):107-112
A recent trend in the Japanese polyolefin industry is reviewed focusing on the commercialization of metallocene produced polyolefins. The potential applications of these polyolefins will also be described. 相似文献
15.
Low-temperature synthesis of anatase-brookite composite nanocrystals: the junction effect on photocatalytic activity 总被引:2,自引:0,他引:2
Ozawa T Iwasaki M Tada H Akita T Tanaka K Ito S 《Journal of colloid and interface science》2005,281(2):510-513
Anatase-brookite composite nanocrystals have successfully been synthesized at 50 degrees C using a simple liquid-phase process. The photocatalytic activity of the sample for the gas-phase oxidation of CH3CHO is 5.4 times greater than that of a single-phase anatase sample with comparable crystallite size and surface area. Electron energy loss spectra suggest that this high activity results from junction between anatase and brookite crystals. 相似文献
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17.
Collisional ionization has been observed in the collision of electronically excited sodium atoms with potassium atoms. By means of the crossed-beam and stepwise laser excitation technique and time-of-flight measurements, the folowing reactions have been investigated: Penning ionization, Na* + K → Na + K+ + e?, and associative ionization, Na* + K → NaK+ + e?. 相似文献
18.
Patterning Effect of a Sol-Gel TiO2 Overlayer on the Photocatalytic Activity of a TiO2/SnO2 Bilayer-Type Photocatalyst 总被引:3,自引:0,他引:3
Akihiko Hattori Yoshifumi Tokihisa Hiroaki Tada Noboru Tohge Seishiro Ito Kazutaka Hongo Ryuichi Shiratsuchi Gyoichi Nogami 《Journal of Sol-Gel Science and Technology》2001,22(1-2):53-61
TiO2 films with a thickness of 75 ± 5 nm (anatase) were formed on SnO2-film (580 ± 80 nm) coated soda-lime glass substrates (SnO2/SL-glass) by a sol-gel method. Although the photocatalytic activity for CH3CHO oxidation (ex > 300 nm) significantly exceeded that of a standard TiO2/quartz sample, it decayed with illumination time (t) at t > 0.75 h. Stripes of anatase TiO2 films of 40 nm in thickness and 1 mm in width were prepared on the SnO2/SL-glass substrate in a 1-mm pitch by photolysis of an organically modified sol-gel film. The TiO2 patterning further increased the photocatalytic activity by a factor of 4.1 as compared to the non-patterned sample, and it was also maintained at 0 < t < 2 h. The flat band potentials of the TiO2 and SnO2 films are determined to be –0.34 and +0.07 V (vs. SHE), respectively, at pH = 7 by the Mott-Schottky plots. On the basis of the results, the outstanding patterning effects could be rationalized in terms of the vectorial charge separation at the interface between TiO2 and SnO2. 相似文献
19.
Kawahara T Soejima T Mitsui T Kiyonaga T Tada H Ito S 《Journal of colloid and interface science》2005,286(2):816-819
Au particles (mean size ca. 3 nm) supported on TiO(2) particles were irradiated by UV light (>300 nm) in aqueous solutions at 278 K. Photo-induced dissolution of Au nanoparticles followed by redeposition occurred in aqueous solutions containing halogen ions. The dissolution of Au nanoparticles yielded a Au(III) complex with a halogen ion; subsequent reduction of the Au(III) complex caused precipitation of larger Au particles on TiO(2). 相似文献
20.
Kanno S Watanabe K Yamagishi I Hirano S Minakata K Gonmori K Suzuki O 《Analytical and bioanalytical chemistry》2011,399(3):1141-1149
A new thermoresponsive polymer separation column was applied to simultaneous analysis of four cardiac glycosides (CGs) being
widely used for the treatment of arrhythmias and heart failure in human blood and urine. This column is composed of an N-isopropylacrylamide polymer, the surface of which undergoes a reversible alteration from hydrophilic to hydrophobic by changing
temperature. The chromatographic separation and retention times can be easily be controlled by adjusting the column temperature.
As the column temperature was changed from 50 to 10 °C over 8 min, five CGs, including deslanoside, digoxin, methyldigoxin,
digitoxin, and digitoxigenin (internal standard) were better resolved. Using these LC conditions, we analyzed four CGs in
human whole blood and urine simultaneously by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Validation data as
functions of recovery rates, linearity, accuracy, and precision were carefully tested; all were generally satisfactory. The
detection limits for the four CGs in both matrices were 0.2–0.3 ng/mL. The method was applied to analysis of methyldigoxin
and its main metabolite digoxin in whole blood and urine samples obtained from a deceased person in actual autopsy case. To
our knowledge, this is the first report describing an LC-MS-MS method using a thermoresponsive column for analysis of drug(s).
The inclusion of the thermoresponsive column in an LC-MS-MS technique seems to extend the possibility for simultaneous analysis
of compounds of different properties, such as hydrophobic precursors and their hydrophilic metabolites in biological samples
within limited analysis times. 相似文献