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961.
Ryoji Takahashi Satoshi Sato Toshiaki Sodesawa Madoka Kato Satoshi Yoshida 《Journal of Sol-Gel Science and Technology》2000,19(1-3):715-718
Structural formation process of Ni/SiO2 and Cu/SiO2 catalysts prepared by solution exchange of wet silica gel was investigated. Microstructures of Cu/SiO2 and Ni/SiO2 were quite different from each other. In the case of Cu/SiO2, Cu particles with diameter of ca. 3–5 nm dispersed homogeneously at less Cu content, and the particle size of Cu as well as pore size of silica gel support increased with increasing Cu content. In the Ni/SiO2, the Ni particles with diameter of ca. 6–10 nm gathered densely to form aggregates in silica matrix resulting in sea-island structure, whereas the size of Ni particle slightly increased with increasing Ni content. The difference in the structure of the metal-silica composites is probably caused by the difference in interaction between silica gel network and metal ions during drying and heating processes. 相似文献
962.
Elucidation of the hydrodesulfurization (HDS) mechanism on molybdenum‐based catalysts using radioisotope tracer methods and reaction kinetics is reviewed. Firstly, to investigate the sulfidation state in Mo/Al2O3 and Co–Mo/Al2O3 catalysts, presulfiding of these catalysts has been performed using a 35S pulse tracer method. Secondly, HDS of radioactive 35S‐labeled dibenzothiophene was carried out over a series of sulfided molybdena–alumina catalysts and cobalt‐promoted molybdena–alumina catalysts in a pressurized flow reactor to estimate the behavior of sulfur on the working catalysts. Finally, sulfur exchange of a 35S‐labeled catalyst with hydrogen sulfide was performed to estimate the relationship between the amount of labile sulfur and catalytically active sites. 相似文献
963.
Okada Yutaka Miyamoto Norikazu Hishimoto Munemitsu Hayashi Takatoshi 《Transition Metal Chemistry》1999,24(3):258-262
Reactions between benzoferrocenes and substituted benzenes gave products resulting from intramolecular and intermolecular ligand exchange. The product ratios were influenced by the number of methyl substituents on the benzene ring; the larger the number, the greater the ratio of intermolecular products. 相似文献
964.
Reflectance and transmittance of 632.8 nm He-Ne laser light for photonic double barrier structures (consisting of a SF10 prism, SiO2 layer, Al or Al2O3 active layer, SiO2 layer and SF10 prism) were measured as a function of the angle of incidence for both the ρ- and s-polarized incidence. Sharp reflection dips and transmission peaks were observed at angles larger than the critical angle of total reflection. The appearance of the transmission peaks can be attributed to resonant photon tunneling through the photonic double barrier structures analogous to resonant electron tunneling through double potential barrier structures. Resonant tunneling is mediated by the long-range surface plasmon polariton in the case of the Al active layer and the electromagnetic guided modes in the case of the Al2O3 layer.This paper was originally presented at the seventh Meeting on Near Field Optics, which was held on July 1, 1998 at Nagoya University, Nagoya, organized by Research Group on Near Field Optics, the Optical Society of Japan, an affiliate of Japan Society of Applied Physics. The authors have won the Near Field Optics Award for their best presentation at the meeting. 相似文献
965.
966.
In Ni single crystals grown by the floating-zone method, it was found that their growth directions tended to concentrate towards the 〈111〉 or the 〈100〉 direction. An interpretation was put forward for the preferred direction of these crystals in terms of thermal stability of the crystallographic planes in the solid-liquid interface. 相似文献
967.
Yoshiyuki Kawase Seiji Yamaguchi Osamu Maeda Akemi Hayashi Ichihiro Hayashi Kazuko Tabata Masako Kondo 《Journal of heterocyclic chemistry》1979,16(3):487-491
Benzofuro[2,3-b]quinoline ( Ia ) and its 11-methyl derivative ( Ib ) were synthesized by demethylcyclization of 3-(o-methoxyphenyl)-1,2-dihydroquinolin-2-ones (VIa,b). Benzofuro[2,3-b]quinoline-11-carboxylic acid (Id) was synthesized by chlorination followed by the action of potassium hydroxide of a lactone (IX) prepared by demethyl-cyclization of 3-(o-methoxyphenyl)-2-oxo-1,2-dihydroquinoline-4-carboxylic acid (VIII). Isomeric benzofuro[3,2-c]quinoline (Ha) and its 6-methyl derivative (IIb) were synthesized by demethyl-cyclization of 3-(o-methoxyphenyl)-1,4-dihydroquinolin-4-ones (XIa,b). Both the methyl derivatives (Ib and IIb) were converted to the carboxylic acids (Id and IId) through condensation with benzaldehyde followed by oxidation. The benzofuroquinolines (Ia,b,d and IIa,b) thus obtained were oxidized to the corresponding N-oxides (IIIa,b,d and IVa,b). 相似文献
968.
Stuart Ibsen Yongxuan Su John Norton Eran Zahavy Tomoko Hayashi Stephen Adams Wolf Wrasidlo Sadik Esener 《Journal of mass spectrometry : JMS》2013,48(7):768-773
The localized conversion of inactive doxorubicin prodrug chemotherapeutics to pharmacalogically active forms is difficult to quantify in mouse tumor models because it occurs only in small regions of tissue. The tumor tissue extraction protocol and LC–MS/MS analysis method described here were optimized to obtain a detection limit of 7.8 pg for the activated doxorubicin and 0.36 ng for the doxorubicin prodrug. This method can be useful for determining the biodistribution and activation efficiency for many different doxorubicin prodrugs. It can also be used for quantification of doxorubicin from tumor models that have poor vascularization resulting in low tissue accumulation. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
969.
970.
Toshiaki Hattori Naoko Tsurumi Ryo Kato Masanori Nakayama 《Analytical sciences》2006,22(12):1577-1580
The adsorption of ion-association complexes on a carbon paste electrode (CPE) was investigated by cyclic voltammetry using an electroactive hydrophobic anion probe. The redox reactions of 2-(5-bromo-2-pyridyl)azo-5-[N-n-propyl-N-(3-sulfopropyl)amino]phenol (5-Br-PAPS), the analytical probe, were irreversible. The reduction of the azo group and the oxidation of the phenol were observed at -0.1 V and 0.9 V vs. SCE, respectively, in a 0.1 mol L(-1) H(2)SO(4) solution. The peak currents for the redox reaction increased with the concentration of the cationic surfactant and the accumulation time. The increase in the ratio of the peak current to the concentration of cationic surfactants was proportional to the hydrophobicity. The peak current for 5-Br-PAPS also increased when a polycation, polyhexamethylene biguanide hydrochloride, was added and was strongly dependent on the ionic strength and pH, in contrast to cationic surfactants. 相似文献