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排序方式: 共有213条查询结果,搜索用时 968 毫秒
101.
Dr. Hendrik O. Lintang Prof. Dr. Kazushi Kinbara Prof. Dr. Takashi Yamashita Prof. Dr. Takuzo Aida 《化学:亚洲杂志》2012,7(9):2068-2072
An organometallic/silica nanocomposite of a 1D cylindrical assembly of a trinuclear gold(I)–pyrazolate complex ([Au3Pz3]) that was confined inside the nanoscopic channels of hexagonal mesoporous silica ([Au3Pz3]/silicahex), emitted red light with a luminescence center at 693 nm upon photoexcitation at 276 nm owing to a AuI? AuI metallophilic interaction. When a film of [Au3Pz3]/silicahex was dipped into a solution of Ag+ in tetrahydrofuran (THF), the resulting nanocomposite material (Ag@[Au3Pz3]/silicahex) emitted green light with a new luminescence center at 486 nm, which was characteristic of a AuI? AgI heterometallic interaction. Changes in the emission/excitation and XPS spectra of Ag@[Au3Pz3]/silicahex revealed that Ag+ ions permeated into the congested nanochannels of [Au3Pz3]/silicahex, which were filled with the cylindrical assembly of [Au3Pz3]. 相似文献
102.
Kazushi Sumitani Takashi Hoshino Toshio Takahashi Hiroo Tajiri Hiroshi Sugiyama Hiroshi Kawata 《Applied Surface Science》2006,252(15):5288-5291
The structure of the Si(1 1 1)-6 × 1-Ag surface is investigated using crystal truncation rod (CTR) scattering along 00 rod. For the measurement, we developed a manipulator suitable for observing CTR scattering at large momentum transfer perpendicular to the surface. The heights of the silver and reconstructed silicon atoms from the substrate were determined. We also compared the obtained positions with those of the Si(1 1 1)-√3 × √3-Ag surface and found that the heights of those reconstructed atoms are almost the same. 相似文献
103.
Nitrogen-based ligands containing an iminopyrrole unit have recently attracted attention because of their flexible complexation to transition metals. Since steric and electronic demands can be readily introduced to the iminopyrrole unit, a wide variety of ligand has been designed and synthesized. In this contribution, we briefly review synthetic and structural features of transition metal complexes with the multidentate iminopyrrolyl ligands and their catalytic activity, especially polymerization of α-olefins. 相似文献
104.
Effect of Water Vapor on Benzene Decomposition Using a Nonthermal-Discharge Plasma Reactor 总被引:4,自引:0,他引:4
Ogata Atsushi Shintani Noboru Yamanouchi Kazushi Mizuno Koichi Kushiyama Satoshi Yamamoto Toshiaki 《Plasma Chemistry and Plasma Processing》2000,20(4):453-467
The effect of water vapor on benzene decomposition in air was investigatedusing a nonthermal-discharge plasma reactor packed with ferroelectricmaterials. The conversion of benzene was found to decrease with an increaseof water concentration. On the other hand, the selectivity to CO2 in thedecomposition products increased with an increase of water concentration. Acomparison between the benzene conversion to CO and CO2 suggested that COformation was suppressed by water to a greater extent than was CO2formation. N2O formation also decreased with an increase of waterconcentration. These results suggest that the activity of oxygen speciesresponsible for the formation of CO and N2O is reduced by water. 相似文献
105.
Optical imaging of an exposed cortex for brain function measurement is an attractive method for both clinical and physiological investigations. Spectral imaging of the exposed cortical tissue enables measurement of the activity-dependent changes in oxy- and deoxy-haemoglobin independently. Since the diffusely reflected light from the exposed cortex is highly scattered in the cortical tissue, the wavelength dependence of the optical properties of the tissue is likely to affect the images of oxy- and deoxy-haemoglobin changes obtained from the spectral images. In this study, the spectral images of the model of exposed cortical tissue are calculated by Monte Carlo simulation to investigate the influence of blurring by tissue scattering on the brain function measurement by the imaging. The images of the change in oxy- and deoxy-haemoglobin obtained from the spectral images at near infrared wavelengths are broadened and blurred due to the scattering in the cortical tissue. The influence of cross talk is more significant in the image calculated from the spectral images at the visible wavelengths. Inappropriate choice of the spectral range of images might increase cross talk and error in the images of oxy- and deoxy-haemoglobin changes. 相似文献
106.
Yohei Ueda Prof. Dr. Hayato Tsurugi Prof. Dr. Kazushi Mashima 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(4):1568-1572
A highly E-selective cross-dimerization of terminal alkynes with either terminal silylacetylenes, tert-butylacetylene, or 1-trimethylsilyloxy-1,1-diphenyl-2-propyne in the presence of a dichlorocobalt(II) complex bearing a sterically demanding 2,9-bis(2,4,6-triisopropylphenyl)-1,10-phenanthroline, activated with two equivalents of EtMgBr, gives a variety of (E)-1,3-enynes. A well-characterized diolefin/cobalt(0) complex, with divinyltetramethyldisiloxane, acted as a catalytically active species without any activation, clearly indicating that a cobalt(0) species is involved in the catalytic cycle. 相似文献
107.
Thermodriven Micrometer‐Scale Aqueous‐Phase Separation of Amphiphilic Oligoethylene Glycol Analogues 下载免费PDF全文
Shunichi Kawasaki Dr. Takahiro Muraoka Haruki Obara Takerou Ishii Prof. Tsutomu Hamada Prof. Kazushi Kinbara 《化学:亚洲杂志》2014,9(10):2778-2788
Thermoresponsive materials with a lower critical solution temperature (LCST) are receiving growing attention, of which examples of non‐polymeric small molecules are limited. Monodisperse oligoethylene glycol amphiphiles that contain aromatic units with a LCST in water have been developed and applied to peptide extraction. Concentration‐dependent hysteretic transmittance changes were observed in response to temperature elevation and reduction. Dynamic light scattering measurements and phase contrast microscopy revealed the formation of micrometer‐sized aggregates upon heating at a concentration above 5.0 mM ; these aggregates self‐assembled to form larger aggregates upon cooling before dissolution. The “interaggregate” interactions are likely to cause the hysteretic behavior. As an application of this thermodriven phase separation, selective extraction of peptide fragments containing high percentages of hydrophobic and aromatic amino acid residues was successfully demonstrated. 相似文献
108.
Takashi Toyao Masayuki Minakata Kazushi Iyatani Afshin Ebrahimi Po-Chou Chen Chung-Bo Tsai Yu Horiuchi Masaya Matsuoka Masakazu Anpo 《Research on Chemical Intermediates》2013,39(1):415-424
A visible-light-responsive TiO2 thin film (Vis-TiO2), possessing a unique columnar structure oriented perpendicular to the substrate, has been prepared by using a radio-frequency magnetron sputtering deposition method. The unique TiO2 thin film was used as a key component of N719 dye-sensitized solar cells (DSSCs). The rough morphology caused by the columnar structure leads to enhanced photovoltaic performances of these DSSCs as a consequence of increased amounts of adsorbed dyes and facilitated diffusion of the electrolyte into Vis-TiO2 film. Additionally, photovoltaic performances of the DSSCs were found to depend strongly on the thickness of the Vis-TiO2 film, which can be readily controlled by adjusting the sputtering time conducted for deposition. Consequently, a solar-to-electric energy conversion efficiency of 2.6 % under AM 1.5 illumination was observed for an optimally performing DSSC that has a Vis-TiO2 film thickness of 6.9 μm, prepared by employing a sputtering time of 700 min. 相似文献
109.
Tetsuya Narushima Masahiro Kitajima Akira Kurokawa Kazushi Miki 《Surface science》2007,601(5):1384-1388
Initial oxidation via ozone on the Si(1 0 0) surface is investigated by measuring surface stress and observing atomic structure via a scanning tunneling microscopy (STM). A similar investigation is also carried out for molecular oxygen and the results are compared. As a result, monotonic increase of the surface stress to the compressive stress side is obtained up to 0.33 N/m for ozone oxidation at room temperature, while molecular oxygen shows only tiny surface stress growth. From the STM observations, it is found that the difference between ozone and molecular oxygen oxidation is the existence of surface etching. As the origin of the surface stress, therefore, the reduction of the intrinsic tensile surface stress due to the reconstructed surface by the etching process is proposed. 相似文献
110.
Tsurugi H Saito T Tanahashi H Arnold J Mashima K 《Journal of the American Chemical Society》2011,133(46):18673-18683
High-valent tantalum complexes having redox-active α-diimine ligands, (α-diimine)TaCl(n) (n = 3, 4), are prepared by the reaction of TaCl(5), α-diimine ligands, and an organosilicon-based reductant, 1-methyl-3,6-bis(trimethylsilyl)-1,4-cyclohexadiene. Reductive cleavage of the C-Cl bond of polyhaloalkanes is accomplished by trichlorotantalum complexes having dianionic α-diimine ligands via electron transfer from the dianionic ligands, whereas oxidative decomposition of tetraphenylborate is observed using tetrachlorotantalum complexes with monoanionic α-diimine ligands through electron transfer to the monoanionic ligands. Chemically oxidized or reduced complexes of (α-diimine)TaCl(4) are isolated as ligand-centered redox products, [Cp(2)Co][(α-diimine)TaCl(4)] and [(α-diimine)TaCl(4)][WCl(6)], where the α-diimine ligand coordinates to the metal center as a dianionic or neutral ligand, respectively. On the basis of EPR measurements of (α-diimine)TaCl(4) complexes (which are key intermediates for reductive cleavage of C-Cl bond and oxidative decomposition of tetraphenylborate), two redox isomers--a tantalum-centered radical and ligand-localized radical--are present in solution. 相似文献