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401.
Takashi Kamegawa Masaya Matsuoka Masakazu Anpo 《Research on Chemical Intermediates》2008,34(4):427-434
A highly dispersed Cr6+-oxide species on silica (Cr/SiO2) was found to act as an efficient photocatalyst for the selective oxidation of CO into CO2 with O2 in the presence of H2 under visible (λ>420 nm) or solar light irradiation at 293 K. UV-Vis, photoluminescence and FT-IR investigations revealed
that the selective reactivity of the photoexcited tetrahedral Cr6+-oxide species ([Cr5+−O−]*) with CO, as well as the high reactivity of the photoreduced Cr6+-oxide species (Cr4+-oxide species) with O2 both play significant roles in this reaction. 相似文献
402.
Mitsuishi M Koishikawa Y Tanaka H Sato E Mikayama T Matsui J Miyashita T 《Langmuir : the ACS journal of surfaces and colloids》2007,23(14):7472-7474
This paper describes the fabrication of hybrid nanoassemblies with polymer brushes and gold nanoparticles enabling detection of nanoscale optical changes based on localized surface plasmon resonance. The reversible and thermosensitive nanoscale actuation is achieved by combining stimuli-responsive polymer brushes and gold nanoparticles independently and selectively assembled on substrates. These hybrid nanoassemblies are assembled on numerous substrates and will be applicable for optoelectronics, nanoactuator, and nanosensor applications. 相似文献
403.
Haik Chosrowjan Seiji Taniguchi Noboru Mataga Fumio Tanaka Daisuke Todoroki Masaya Kitamura 《Chemical physics letters》2008,462(1-3):121-124
Ultrafast fluorescence dynamics of FMN in FMN-binding protein (FMN-bp), and its mutated proteins, W32Y and W32A, were investigated by the fluorescence up-conversion method. Fluorescence lifetimes were 167 fs (96%) and 1.5 ps (4%) in wild-type FMN-bp (WT), and 3.4 ps (23%), 18.2 ps (74%), and 96 ps (3%) at 530 nm in W32Y, and 30.1 ps in W32A. The fluorescence lifetime of W32A, in which Trp-32 was absent, was about 140 times longer than that of WT. Tyr-32 in W32Y was not so effective quencher as Trp-32 in WT. This was explained in terms of different ionization potentials of quenchers and average donor–acceptor distances in the protein. 相似文献
404.
We report enhanced second harmonic generation from nanostructured multilayers in combination with nonlinear optical polymer nanosheets and gold nanoparticles. 相似文献
405.
A heterogeneous mono(phosphine)-Rh catalyst system silica-SMAP-Rh(OMe)(cod), where silica-SMAP stands for a caged, compact trialkylphosphine (SMAP) supported on silica gel, showed broad applicability toward the hydrogenation of hindered ketones. Doubly alpha-branched ketones such as diisopropyl ketone was hydrogenated under nearly atmospheric conditions. Di-tert-butyl ketone could be hydrogenated under more forcing conditions. 相似文献
406.
Ohgaru T Shimizu R Okamoto K Kawashita N Kawase M Shirakuni Y Nishikiori R Takagi T 《Journal of chemical information and modeling》2008,48(4):910-917
Conventional comparative molecular field analysis (CoMFA) requires at least 3 orders of experimental data, such as IC 50 and K i, to obtain a good model, although practically there are many screening assays where biological activity is measured only by rating scale. To improve three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis, we developed in this study a modified ordinal classification-oriented CoMFA using partial-least-squares generalized linear regression and ridge estimation. The modified Logistic CoMFA was validated using a corticosteroid binding globulin receptor binding data set, a benchmark for 3D-QSAR, and an acetylcholine esterase inhibitor data set. Our results show that modification of Logistic CoMFA enhanced both prediction accuracy and 3D graphical analysis. In addition, the 3D graphical analysis of the modified Logistic CoMFA was much improved. This improvement resulted in more accurate information on the binding mode between proteins and ligands than in the case of conventional CoMFA. 相似文献
407.
408.
Hara K Tayama S Kano H Masuda T Takakusagi S Kondo T Uosaki K Sawamura M 《Chemical communications (Cambridge, England)》2007,(41):4280-4282
A single-crystal silicon surface was modified with a bisoxazoline-Pd molecular layer and utilized as a highly efficient (catalyst turnover number up to 780,000, 110 degrees C, 72 h) and recyclable catalyst in the aerobic oxidation of benzylic alcohols. 相似文献
409.
Αddition reactions of (1-methoxyalkyl)triphenylphosphonium ylides, derived from the corresponding Wittig salts and n-BuLi, to aldehydes were investigated. It was revealed that the betaine LiX complexes, the primary adducts, were converted to α-hydroxyketones, prior to the formation of oxaphosphetanes, by addition of aqueous NH4Cl at low temperature. 相似文献
410.
A variable selection method using global score estimation is proposed, which is applicable as a selection criterion in any
multivariate method without external variables such as principal component analysis, factor analysis and correspondence analysis.
This method selects a subset of variables by which we approximate the original global scores as much as possible in the context
of least squares, where the global scores, e.g. principal component scores, factor scores and individual scores, are computed
based on the selected variables. Global scores are usually orthogonal. Therefore, the estimated global scores should be restricted
to being mutually orthogonal. According to how to satisfy that restriction, we propose three computational steps to estimate
the scores. Example data is analyzed to demonstrate the performance and usefulness of the proposed method, in which the proposed
algorithm is evaluated and the results obtained using four cost-saving selection procedures are compared. This example shows
that combining these steps and procedures yields more accurate results quickly. 相似文献