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101.
Tsukamoto D Ikeda M Shiraishi Y Hara T Ichikuni N Tanaka S Hirai T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(35):9816-9824
Semiconductor TiO2 particles loaded with WO3 (WO3/TiO2), synthesized by impregnation of tungstic acid followed by calcination, were used for photocatalytic oxidation of alcohols in water with molecular oxygen under irradiation at λ>350 nm. The WO3/TiO2 catalysts promote selective oxidation of alcohols to aldehydes and show higher catalytic activity than pure TiO2. In particular, a catalyst loading 7.6 wt % WO3 led to higher aldehyde selectivity than previously reported photocatalytic systems. The high aldehyde selectivity arises because subsequent photocatalytic decomposition of the formed aldehyde is suppressed on the catalyst. The TiO2 surface of the catalyst, which is active for oxidation, is partially coated by the WO3 layer, which leads to a decrease in the amount of formed aldehyde adsorbed on the TiO2 surface. This suppresses subsequent decomposition of the aldehyde on the TiO2 surface and results in high aldehyde selectivity. The WO3/TiO2 catalyst can selectively oxidize various aromatic alcohols and is reusable without loss of catalytic activity or selectivity. 相似文献
102.
Iridium-chiral diphosphine complex catalyzes an enantioselective intramolecular Pauson-Khand-type reaction to give various chiral bicyclic cyclopentenones. The enantioselective reaction proceeds more smoothly and enantioselectively under a lower partial pressure of carbon monoxide. Moreover, aldehyde can be used as a CO source in the enantioselective carbonylative coupling. 相似文献
103.
104.
The construction of the linearized four-dimensional multisupergravity from five-dimensional linearized supergravity with discretized fifth dimension is presented. The one-loop vacuum energy is evaluated when (anti)periodic boundary conditions are chosen for (bosons) fermions, respectively, or vice versa. It is proposed that the relation between discretized M-theory and strings may be found in the same fashion. 相似文献
105.
Matsuta K. Onishi T. Fukuda M. Minamisono T. Mihara M. Sasaki M. Yamaguchi T. Miyake T. Sato K. Minamisono K. Ohsumi F. Muramoto Y. Oui S. Ha C. Tanaka K. Kidera K. Morishita A. Tsubota T. Sumikama T. Kitagawa A. Torikoshi M. Kanazawa M. Nishio T. Koda S. Ohtsubo T. Fukuda S. Nojiri Y. Momota S. Ozawa A. Yoshida K. Suzuki T. Kobayashi T. Tanihata I. Hanna S.S. Alonso J.R. Krebs G.F. Symons T.J.M. 《Hyperfine Interactions》1999,120(1-8):713-717
The degrees of nuclear spin polarization of 8,12B, 9C, 12N, 13O, 20,21F, 23Mg, 27Si and 39Ca produced in the high energy 12,13C, 16O, 22Ne, 24Mg, 28Si and 40Ca ions on Be collisions have been measured systematically, for the technical developments of the nuclear moment studies as
well as the hyperfine interaction studies by means of β-NMR technique. The fragment momentum dependences were well reproduced
by the simple kinematical model. Incident energy dependence and the mass dependence as well as the reaction angle dependences
were qualitatively explained by the mixing of the near and far side collisions.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
106.
Shunsuke Kanematsu Kazuhiko Matsumoto Rika Hagiwara 《Electrochemistry communications》2009,11(6):1312-1315
Fluorohydrogenate ionic liquids of quaternary phosphonium cations, tri-n-butylmethylphosphonium (P4441) fluorohydrogenate, tetra-n-butylphosphonium (P4444) fluorohydrogenate, and tri-n-butyl-n-octylphosphonium (P4448) fluorohydrogenate, have been synthesized by the metatheses of anhydrous hydrogen fluoride and the corresponding phosphonium chloride precursors. All the obtained salts have melting points below room-temperature with a vacuum-stable composition of P444m(FH)2.3F (m = 1, 4, and 8) and were characterized by density, conductivity, and viscosity measurements. Linear sweep voltammetry with a glassy carbon working electrode shows that the P444m(FH)2.3Fs have wide electrochemical windows exceeding 5.2 V. In particular, P4441(FH)2.3F has an electrochemical window of 6.0 V, which is the widest among fluorohydrogenate ionic liquids reported to date. The thermal stability of these ionic liquids is also improved compared to the salts of N-heterocyclic ammonium cations. 相似文献
107.
108.
We have analyzed the transfer efficiency of ballistic electron emission microscopy (BEEM), taking the finite spot size of the emitted electron beam from scanning probes into account. Three-dimensional diffraction from an aperture at a surface-metal/air interface is introduced to model an effect caused by the finiteness of spot size. As a general trend, the diffraction decreases BEEM transfer efficiency. The diffraction effect increases as the spot size decreases and the air-gap distance increases. In a Au/GaAs sample, BEEM transfer efficiency markedly deteriorates down to 6% of the value derived from a conventional planar tunneling theory when a spot size of 0.2 nm, an air-gap distance of 0.6 nm, and an electron energy of 0.2 eV, measured from the bottom of the GaAs conduction band, are assumed. BEEM transfer efficiency is markedly dependent on the spot size of the emitted hot electron. This result indicates that the BEEM current depends on the spatial resolution of the scanning probe, that is, the condition of the tip apex. 相似文献
109.
Y. Nojiri 《Hyperfine Interactions》1990,60(1-4):599-614
Experimental developments recently made in the beta-NMR measurements are reviewed. For production of polarized beta-emitters,
the tilted foil technique has been successfully combined with the NMR. The low- and intermediate-energy heavy-ion reactions
were recently found to be another sources of polarized beta-emitters. To achieve wide applicability of the NMR technique to
nuclei far from stability, the tilted foil technique and the projectile fragmentation process in high-energy heavy-ion collisions
were recently combined with the beta-NMR technique in the fragment separator built at the LBL. 相似文献
110.
Mason K Chang J Garlatti E Prescimone A Yoshii S Nojiri H Schnack J Tasker PA Carretta S Brechin EK 《Chemical communications (Cambridge, England)》2011,47(21):6018-6020
The use of "double-headed" phenolic oximes produces a trigonal antiprismatic [Fe(III)(3)](2) cluster with an "internal cavity" filled with an additional Fe(3+) ion. Magnetic measurements reveal that the competition between different exchange interactions leads to a low-spin ground multiplet weakly separated in energy from a complex pattern of low-lying excited levels. 相似文献