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61.
Kazuhiro Sugamoto Chiaki Kurogi Yoh-ichi Matsushita Takanao Matsui 《Tetrahedron letters》2008,49(47):6639-6641
Naturally occurring chalcones, namely 4-hydroxyderricin (1), xanthoangelol H (2), deoxyxanthoangelol H (3), and deoxydihydroxanthoangelol H (4), were first synthesized and evaluated for antibacterial activities. 相似文献
62.
Geng F Xin H Matsushita Y Ma R Tanaka M Izumi F Iyi N Sasaki T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(30):9255-9260
We report the synthesis of a new series of layered hydroxides based on rare-earth elements with a composition of RE(OH)2.5Cl(0.5).0.8 H2O (RE: Eu, Tb, etc.) through the homogeneous precipitation of RECl3.x H2O with hexamethylenetetramine (HMT). Rietveld analysis combined with direct methods revealed an orthorhombic layered structure comprising a positively charged layer of [RE(OH)2.5-(H2O)0.8]0.5+ and interlayer Cl- ions. The Cl- ions were readily exchangeable for various anions (NO3-, SO4(2-), dodecylsulfonate, etc.) at ambient temperature. Photoluminescence studies showed that the compounds display typical RE3+ emission. With rare-earth-based host layers and tunable interlayer guests, the new compounds may be of interest for optoelectronic, magnetic, catalytic, and biomedical materials. 相似文献
63.
Yashima M Enoki M Wakita T Ali R Matsushita Y Izumi F Ishihara T 《Journal of the American Chemical Society》2008,130(9):2762-2763
MEM nuclear density analysis from neutron diffraction data measured in situ at 1015.6 degrees C has indicated the two-dimensional network of curved O2-O3-O2 oxide-ion diffusion paths on the (Pr,La)-O layer in a K2NiF4-type structured oxide-ionic and electronic mixed conductor (Pr0.9La0.1)2(Ni0.74Cu0.21Ga0.05)O4+delta. 相似文献
64.
In this paper we apply the Douglas–Rachford (DR) method to solve the problem of finding a point in the intersection of the interior of a closed convex cone and a closed convex set in an infinite-dimensional Hilbert space. For this purpose, we propose two variants of the DR method which can find a point in the intersection in a finite number of iterations. In order to analyse the finite termination of the methods, we use some properties of the metric projection and a result regarding the rate of convergence of fixed point iterations. As applications of the results, we propose the methods for solving the conic and semidefinite feasibility problems, which terminate at a solution in a finite number of iterations. 相似文献
65.
We study almost K?hler-Einstein structures on 8-dimensional Walker manifolds, i.e., pseudo-Riemannian 8-manifolds admitting
a field of parallel null 4-planes, whence the metric is of neutral signature. We construct on
explicit almost K?hler-Einstein Walker metrics which are not K?hler. An appropriate restriction induces examples of such
metrics on the 8-torus, thereby producing a counterexample to Goldberg’s conjecture in the case of neutral signature.
S. Haze passed away on 15 March 2006. 相似文献
66.
67.
T. Mochiku Y. Hata T. Wuernisha Y. Matsushita Y. Katsuya S. Ishimaru M. Tanaka K. Kobayashi A. Hoshikawa T. Ishigaki H. Yasuoka K. Hirata 《Physica C: Superconductivity and its Applications》2009,469(15-20):960-964
Heavily Fe-substituted Ba2YCu3O6+δ-type compound FeSr2YCu2O6+δ exhibits superconductivity around 60 K, only when it is annealed in N2 and subsequently in O2. Cationic distribution in this compound is strongly dependent on ionic radius at the Y site, and its superconducting properties are affected by the cationic distribution. In contrast, although the compound with the substitution of fluorite-type unit for Y has cationic order, it does not exhibit superconductivity. We have analyzed the crystal structure of the compounds with the substitution of other lanthanoid elements for Y and with substitution of fluorite-type unit for Y. 相似文献
68.
S. Kawai E.S. Otabe M. Kiuchi T. Matsushita T. Nomura H. Yamauchi T. Motohashi S. Okayasu 《Physica C: Superconductivity and its Applications》2009,469(15-20):1224-1228
Critical current density was measured for oxygen-controlled (Bi, Pb)-2223 single crystals before and after the irradiation with gold ions in a magnetic field parallel to the irradiation-induced defects along the c-axis. Eleven specimens prepared in different annealing conditions were measured. The condensation energy density of each specimen was evaluated from the observed critical current density by using the summation theory of pinning forces of columnar defects and the flux creep theory. It was found that the specimen heat-treated at 1 atm in oxygen atmosphere has the highest condensation energy density among all specimens. Hence, it is speculated that the optimum oxygen pressure for the anneal is around 1 atm. 相似文献
69.
Tadashi Ishigaki Zoran S. Nikolic Tomoaki Watanabe Nobuhiro Matsushita Masahiro Yoshimura 《Solid State Ionics》2009,180(6-8):475-479
In case of reactions, it is a necessary condition that the free energy of formation, ΔfG, of the product is lower than the total free energies of formation of the reactants. The free energy of all reactions and/or all compounds have not been determined in the literature. In this paper, we report the formation, stability, and reactions for all compounds based on their free energies. However, it also seems possible to discuss them based on their lattice energies, because it can be calculated for many compounds if their composition, structure and their lattice parameters are known. Also, we can discuss the formation, stability, etc., for compounds excluding small effects due to temperature and entropy. As a result of the calculations, the lattice energy correlates with the perovskite distortion. 相似文献
70.
Electrochemical reactions of manganese(III) complexes, MnIII(L)X (L; salen, salpn, 5-NO2–salen or 5-NO2–salpn, X; Cl, Br or NO2) and MnIII(L’)2X (L’; N-Bu-sal, N-Oct–sal, N-Oct–5-Br–sal or N-Oct–5-NO2–sal, X; Cl or Br), were investigated by voltammetry at a glassy carbon electrode in the absence/presence of Cl− in acetonitrile solution. By the addition of Cl−, oxidation processes of MnIII(L)X and MnIII(L’)2X have been found to be improved from quasi-reversible to reversible, and their oxidation products, [MnIV(L)X]+ and [MnIV(L’)2X]+, were stabilized by the combination with Cl− resulting in [MnIV(L)Cl2] and [MnIV(L’)2Cl2], respectively. On the other hand, the reduction processes of MnIII(L)X and MnIII(L’)2Cl were not so significantly affected by Cl− as those observed for their oxidation. Other types of manganese(III) complexes and iron(III) complex were also investigated. The present study may clarify the role of Cl− being involved in OEC (oxygen-evolving center) in photosystem II. 相似文献