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141.
Takaya Mitsui Ryo Masuda Naohisa Hirao Ko Mibu Makoto Seto 《Hyperfine Interactions》2012,205(1-3):97-100
Formation of LaFeO3 nanoparticles obtained from thermal decomposition of organometallic precursors was investigated as a function of the heat-treatment temperature. The precursors heat-treated below 300°C were amorphous, but above 350°C a single-phase of nanocrystalline LaFeO3 was formed. The LaFeO3 nanoparticles showed the superparamagnetic behavior in both magnetization and M?ssbauer measurements. With increasing heat-treatment temperature, the crystallite size of LaFeO3 nanoparticles was gradually increased. The quadrupole splitting and isomer shift of paramagnetic doublet pattern were affected by the growth of LaFeO3 particles. 相似文献
142.
Shigehiro Komura T. Takeda Y. Kawabata S.K. Ghosh H. Seto M. Nagao 《The European physical journal. E, Soft matter》2001,5(3):329-336
Dynamical fluctuations of microemulsion and lamellar structures in a ternary amphiphilic system C12E 5/water/n-octane are studied by means of neutron spin echo spectrometry. The decay rate of the time correlation of the concentration
was analyzed in terms of a theory (M. Nonomura, T. Ohta, J. Chem. Phys. 110, 7516 (1999)), in which both van Hove and hydrodynamic interactions are considered. The result shows that the time correlation
function is expressed mostly by a single exponential determined exclusively by hydrodynamic interactions.
Received 1 December 1999 and Received in final form 12 March 2001 相似文献
143.
Six optical isomers of 2-(4-diphenylmethyl-1-piperazinyl)ethyl 5-(4,6-dimethyl-2-oxo-1,3,2-dioxaphosphorinan-2-yl)-1,4-dihydro-2, 6-dimethyl-4-(3-nitrophenyl)-3-pyridinecarboxylate dihydrochloride (NIP-101, 1.2HCl.2H2O), a potent calcium antagonist, were successfully prepared by using optically active (2R,4R)-(-)- and (2S,4S)-(+)-2,4-pentanediols, and cis-2,4-pentanediol and optically active (S)-(+)-2-methoxy-2-phenylethanol. Their proton nuclear magnetic resonance investigations demonstrate that the 1,3,2-dioxaphosphorinane group is conformationally constrained around the C-P bond. Calcium-antagonistic and hypotensive activities of the optical isomers were examined and found to depend mainly on the absolute configuration at a stereogenic center in the 1,4-dihydropyridine ring rather than the configuration of the 1,3,2-dioxaphosphorinane moiety. 相似文献
144.
Tadashi Eguchi Yasumasa Dekishima Hideyuki Tamegai Norihiko Misawa Haruo Seto 《Tetrahedron》2005,61(8):2027-2035
Carotenoids are important natural pigments produced by various microorganisms and plants. Specific deuterium-labeling of these compounds is invaluable in biochemical and physiochemical research. In this paper, preparation of highly deuterated zeaxanthin, lycopene, and β-carotene using engineered Escherichia coli with fully deuterated mevalonate is described. Also described are physico-chemical properties of the obtained deuterated carotenoids. 相似文献
145.
Seto T Akinaga H Takano F Koga K Orii T Hirasawa M 《The journal of physical chemistry. B》2005,109(28):13403-13405
We have recently developed a method to fabricate monodispersed Ni/NiO core-shell nanoparticles by pulsed laser ablation. In this report, the size-dependent magnetic properties of monodispersed Ni/NiO core-shell nanoparticles were investigated. These nanoparticles were formed in two steps. The first was to fabricate a series of monodispersed Ni nanoparticles of 5 to 20 nm in diameter using a combination of laser ablation and size classification by a low-pressure differential mobility analyzer (DMA). The second step was to oxidize the surfaces of the Ni particles in situ to form core-shell structures. A superconducting quantum interference device (SQUID) magnetometer was used to measure the magnetic properties of nanostructured films prepared by depositing the nanoparticles at room temperature. Ferromagnetism was observed in the magnetic hysteresis loop of the nanostructured films composed of core-shell nanoparticles with core diameters smaller than the superparamagnetic limit, which suggests the spin of Ni core was weakly exchange coupled with antiferromagnetic NiO shell. In contrast, smaller nanoparticles with core diameters of 3.0 nm exhibited superparamagnetism. The drastic change in the hysteresis loops between field-deposited and zero-field-deposited samples was attributable to the strong anisotropy that developed during the magnetic-field-assisted nanostructuring process. 相似文献
146.
147.
Rie Haruki Masanori Koshimizu Fumihiko Nishikido Ryo Masuda Yasuhiro Kobayashi Makoto Seto Yoshitaka Yoda Shunji Kishimoto 《Hyperfine Interactions》2016,237(1):71
The dynamics of iodine ions in potassium iodide (KI) and lithium iodide (LiI) aqueous solutions have been studied through 127I nuclear resonant quasi-elastic scattering (NRQES). A newly developed Si (12 2 2) double crystal monochromator for 127I 57.6 keV excitation is used. Broadening due to a diffusive motion is measured in the energy spectra of the NRQES from the solutions. 相似文献
148.
A solid-phase procedure has been developed for the synthesis of chiral N-acylethylenediamine ligands. The ligands are obtained in good yield and purity, without the need for chromatography or other purification methods. Several new and previously reported ligands were prepared using this procedure. These compounds were examined as catalysts for the enantioselective addition of alkylzinc reagents to aldehydes. In all cases, the crude ligands from the solid-phase syntheses catalyzed the reactions with similar yields and stereoselectivities when compared to reactions using ligands that had been purified by standard methods. Preliminary studies were also performed with ligands 3a and 3f as catalysts for the addition of alkenylzinc reagents to aldehydes to give chiral allylic alcohols. Ligand 3f was found to catalyze this addition reaction in up to 76% ee. 相似文献
149.
Kentaro Okuma Jun-ichi Seto Ken-ichi Sakaguchi Saori Ozaki Noriyoshi Nagahora Kosei Shioji 《Tetrahedron letters》2009,50(24):2943-1400
Reaction of 2-phenylethynyl N-tosylanilide prepared by Pd-free procedure with ZnBr2 (3 equiv) in refluxing toluene gave N-tosyl-2-phenylindole in 93% yield. Treatment of 2-phenylethynylaniline with ZnBr2 (1 equiv) in refluxing toluene resulted in the formation of 2-phenylindole in 91% yield. Catalytic ZnBr2 (0.05 equiv) effectively reacted with 2-alkynylanilines to afford 2-substituted indoles in high yields. Thus, complete Pd-free zinc catalyzed hydroamination of 2-alkynylanilines was achieved. 相似文献
150.
Imai T Hiraoka R Seto T Kovalenko A Hirata F 《The journal of physical chemistry. B》2007,111(39):11585-11591
The three-dimensional distribution function theory of molecular liquids is applied to lysozyme in mixtures of water and noble gases. The results indicate that the theory has the capability of predicting the protein-ligand binding sites and affinities. First, it is shown that the theory successfully reproduces the binding sites of xenon found by X-ray crystallography. Then, the ability of the theory to predict the size selectivity of noble gases is demonstrated. The effect of water on the selectivity is clarified by a theoretical analysis. Finally, it is demonstrated that the dose-response curve, which is employed in experiments for examining the binding affinity, is realized by the theory. 相似文献