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61.
Nishikiori H Sasai R Takagi K Fujii T 《Langmuir : the ACS journal of surfaces and colloids》2006,22(7):3376-3380
Spironaphthoxazine (SNO) and Zn2+ were intercalated into montmorillonite interlayers hydrophobically modified by the alkyltrimethylammonium cation during UV light irradiation. The fluorescence spectra of the montmorillonite composites were observed to vary with an increase in the UV and visible light irradiation times. These composites exhibited two types of fluorescence emissions: F1, which originates from a new species, Xs, which is different from SNO (ring-closed form) and merocyanine (MC; ring-open form), and F2, which originates from the MC-Zn complex. With increasing UV light irradiation time, the F1 intensities decreased, whereas the F2 intensities increased. Xs, which is an intermediate species between SNO and MC, was transformed into MC and then coordinated with Zn2+ (i.e., MC-Zn complex) during the UV light irradiation. The reaction rate of the formation of the MC-Zn complex decreased for the hydrophobically modified montmorillonite due to a longer alkyl chain. The retrieval changes in the F1 and F2 intensities were observed with an increasing visible light irradiation time, implying the dissociation of the MC-Zn complex into Xs and Zn2+. The dissociation especially occurred for the hydrophobically modified montmorillonite with a longer alkyl chain. The formation and disappearance of Xs and the MC-Zn complex obeyed first-order kinetics, and therefore the interconversion between Xs and MC could be regarded as the rate-determining step of the whole reaction during the UV and visible light irradiations. The photoinduced reactions of the SNO species and Zn2+ were profoundly affected by the physicochemical environment provided by the clay interlayers. It is concluded that the present photoreactions can be controlled not only by the amounts of the intercalated SNO species and Zn2+, but also by the hydrophobic environment created by the surfactant molecules. 相似文献
62.
Shinobu Tsutsui Hiromasa Tanaka Shigeki Matsumoto 《Journal of organometallic chemistry》2006,691(4):595-603
The reduction of p-anisyl(1,2,3-tri-tert-butylcycloprop-2-en-1-yl)dichlorogermane (1) with potassium in the presence of an excess of tert-butyldimethylsilane in benzene under reflux gave p-anisyl(tert-butyldimethylsilyl)(1,2,3-tri-tert-butylcycloprop-2-en-1-yl)germane (4) in 15% yield. The formation of 4 indicates that p-anisyl(1,2,3-tri-tert-butylcycloprop-2-en-1-yl)germylene (2), which is the first example of a (cycloprop-2-en-1-yl)germylene derivative, was generated and trapped by the hydrosilane. The DFT calculations revealed that the cis-2-p-anisyl-1,3,4-tri-tert-butyl-2-germabicyclo[1.1.0]butane-2,4-diyl structure cis-5 is 8.0 kJ/mol more stable than cis-2. The NBO analysis revealed that cis-5 has a 2-germabicyclo[1.1.0]butane diradical character. 相似文献
63.
Hiroaki Kakiuchi Hiromasa Ohmi Takahiro Yamada Keiji Yokoyama Kohei Okamura Kiyoshi Yasutake 《Plasma Chemistry and Plasma Processing》2012,32(3):533-545
Silicon oxide films are deposited in atmospheric-pressure (AP) He/O2/HMDSO plasma excited by a 150?MHz VHF power using a cylindrical rotary electrode. The atomic bonding configurations and deposition rate are studied by controlling the O2 concentration (O2/HMDSO source ratio) and VHF power density, the other parameters being maintained constant. Under the addition of 0.03?% O2 to the process gas mixture (O2/HMDSO????0.09), AP-VHF plasma greatly enhances the fragmentation and oxidation of HMDSO, so that an almost inorganic film is obtained at a very high deposition rate of 33?nm?s?1. A silicon oxide coating on a polycarbonate pane is demonstrated with no significant thermal deformation of the pane, showing that AP-VHF plasma would be an efficient coating tool for polymer substrates. 相似文献
64.
Influence of adding carbon nanotubes on photoelectric conversion properties of dye-doped titania gel
Hiromasa Nishikiori Takuma Ohta Yohei Uesugi Hiroyuki Itai Morinobu Endo Tsuneo Fujii 《Research on Chemical Intermediates》2012,38(8):1857-1869
Multiwalled carbon nanotubes (MWCNTs) were incorporated into amorphous dye-doped titania gel by the sol?Cgel method at room temperature. The working electrodes were prepared by coating the ITO glass with the sol?Cgel titania precursor containing the dye and MWCNTs. The photoelectric conversion properties of the electrodes were examined by simple spectroscopic and electric measurements. The photocurrent spectrum originated from the absorption of the dye. The short circuit photocurrent was enhanced by adding a small amount of MWCNTs evenly to the amorphous dye-doped titania gel. The open circuit voltage was due to the semiconducting characteristics property of the titania gel. The experimental results indicated the electron transport from the dye excited states to the MWCNTs through the titania gel. The MWCNTs functioned as bridges between the titania and ITO. Steam treatment of the titania gel electrodes significantly increased the photoelectric performance due to crystallization of the titania and enhancement of the dye?Ctitania interaction forming the chelate complex on the titania particle surface. 相似文献
65.
Yong Li Meng-Chu Zhu Man-Li Zhang Yu-Fang Wang Mei Dong Qing-Wen Shi Chang-Hong Huo Françoise Sauriol Hiromasa Kiyota Yu-Cheng Gu Bin Cong 《Tetrahedron letters》2012,53(21):2601-2603
Two novel sesquiterpene dimers, achillinin B and C, were isolated from the flowers of Achillea millefolium. The structures were elucidated by extensive spectroscopic analysis. A plausible biosynthetic pathway of achillinin B and C by Diels–Alder reaction of the corresponding guaiane sesquiterpenoids is also discussed. 相似文献
66.
Y.X. Watanabe A. Yoshida T. Fukuda T. Sekine Y. Watanabe H. Ikezoe Y. Nagame T. Ikuta I. Nishinaka Y. Mizoi J. Nakano M. Hirai H. Sakurai H. Kobinata Y. Pu K. Kimura M. Ishihara 《The European Physical Journal A - Hadrons and Nuclei》2001,10(4):373-379
A systematic study of the sub-barrier fusion reactions with neutron-rich projectiles has been carried out for three isotopes
27,29,31Al bombarding a 197Au target. A target chamber equipped with a target stack and sets of MWPC was employed in order to enhance the efficiency
of the radioactive beam experiment. Coupled-channel calculations including the quadrupole excitations do not well fit the
measured fusion excitation functions, whereas flat barrier distributions to represent the coupling to the neutron transfer
largely account for the observed enhancement of the sub-barrier fusion cross-sections.
Received: 13 March 2001 / Accepted: 27 April 2001 相似文献
67.
Hiromasa Nishikiori Nobuaki Tanaka Tsuneo Fujii 《Research on Chemical Intermediates》2000,26(5):469-482
Dip-coated thin films including rhodamine B have been prepared using the sol-gel reaction of tetraethyl orthosilicate under
relative humidity of 30% and 60%. They have been aged under relative humidity of 20%, 60%, and 95% for 5 days. According to
the absorption spectra, just after the preparation of the films and under higher humidity, a larger amount of the dimers (H-and
J-types) were formed in the films. Five days after the preparation of the films and aged under higher humidity, the H-dimer
increased. On the other hand, the J-dimer increased, regardless of humidity under which the films were aged. 相似文献
68.
Single-molecular switching phenomena in monolayer arrays of subphthalocyanine adsorbed on Cu(1 0 0) surface were investigated by scanning tunneling microscopy (STM) under ultrahigh vacuum. The molecules evaporated on the surface arranged in a square lattice taking the Cu(1 0 0)SubPc(5 × 5) epitaxy. During continuous STM imaging at fixed tunneling conditions the topography of the individual molecules spontaneously changed between the high and low states. This topographic change was attributed to orientational switching between the upward and downward adsorption of the axial Cl atom of the molecule on the Cu surface. Molecular energy calculations and statistical thermodynamic evaluation concluded that the tip-triggered disturbance in the close-packed molecular array induced the molecular rearrangement accompanied with the stochastic orientational switching. 相似文献
69.
Reaction-diffusion systems of activator-inhibitor type are studied on an N-dimensional ball with the homogeneous Neumann boundary conditions. Under the condition that the activator diffuses slowly, reacts rapidly and the inhibitor diffuses rapidly, reacts moderately, we show that the system admits a family of spherically symmetric internal transition layer equilibria. The method of proof consists of rigorous asymptotic expansions and a Lyapunov-Schmidt reduction. 相似文献
70.
I. Mori Y. Fujita K. Ikuta Y. Nakahashi K. Kato K. Tamura M. Ohji 《Fresenius' Journal of Analytical Chemistry》1989,334(1):49-52
Summary A simple and highly sensitive spectrophotometric determination of iron with pyrogallolphthalein in a micellar medium of non-ionic surfactant is proposed. This method is based on the kinetic-catalytic action of iron(III) upon the decomposition reaction between pyrogallolphthalein and potassium perdisulphate at pH 2.4–2.9 in the presence of Triton X 100 as a non-ionic surfactant. The calibration graph is linear over the range 10–600 ng iron(III) per 10 ml in spectrophotometry (apparent molar absorption coefficient for decomposition was 1.25×10–6 l per mole per cm at 385 nm). The method was applied to assay and recovery tests for artificial waste water with satisfactory results (recovery 97.6%–103.5%).
Application of xanthene derivatives in analytical chemistry. Part LXXV. Part LXXIV see ref. [1] 相似文献
Kinetische und katalytisch-spektralphotometrische Eisenbestimmung mit Hilfe von Pyrogallolphthalein und Kaliumperdisulfat in Gegenwart eines nichtionischen Tensids
Application of xanthene derivatives in analytical chemistry. Part LXXV. Part LXXIV see ref. [1] 相似文献