排序方式: 共有107条查询结果,搜索用时 578 毫秒
101.
Tomohito Kadota 《Journal of Mathematical Analysis and Applications》2006,323(2):1387-1401
This paper discusses a prey-predator system with strongly coupled nonlinear diffusion terms. We give a sufficient condition for the existence of positive steady state solutions. Our proof is based on the bifurcation theory. Some a priori estimates for steady state solutions will play an important role in the proof. 相似文献
102.
103.
[reaction: see text] The first synthetic application of 2-methyl-2-vinyloxirane as a masked dienolate has been successfully demonstrated in the direct vinylogous Mannich-type reaction with an alpha-imino ester as an electrophile. The Mannich adduct was a useful intermediate en route to cis-5-substituted pipecolinic acid ethyl ester under simple hydrogenation conditions. 相似文献
104.
Tomohito Kameda Hidenori Takeuchi Toshiaki Yoshioka 《Journal of Physics and Chemistry of Solids》2011,72(6):846-851
We report on aqueous Cu2+ uptake by Ni-Al layered double hydroxides (Ni-Al LDHs) modified with citrate (C6H5O73−), malate (C4H4O52−), and tartrate (C4H4O62−) anions via coprecipitation. Dropwise addition of a mixed aqueous solution of Ni(NO3)2 and Al(NO3)3 to the respective organic acid solutions at a constant pH of 7.0-9.0 afforded LDHs with intercalated C6H5O73− and Ni(C6H5O7)−, C4H4O52−, and C4H4O62− in their interlayers. The anions were also likely adsorbed on the LDH surface. Citrate·Ni-Al LDH could rapidly take up Cu2+ at a constant pH of 5.0, mainly via chelation by the intercalated and adsorbed anions, rather than coprecipitation with dissolved Al3+ to form Cu-Al LDH. By contrast, malate and tartrate were not active as chelating agents, probably because they formed bridges between brucite-like layers by direct coordination of the two −COO− groups with Al3+ in those layers. 相似文献
105.
Mitsuhiro Okimoto Takashi Yoshida Masayuki Hoshi Tomohito Chiba Kei Maeo 《合成通讯》2013,43(21):3134-3139
Various biaryl methanols were electrooxidized into the corresponding biaryl ketones in good yields and under very mild reaction conditions. Because of the relatively high oxidation potential, bulky structure, and somewhat poor solubility, biaryl methanols do not readily undergo direct electrooxidative transformations as a synthetic step toward the corresponding biaryl ketones. Herein, we report the successful indirect electrooxidation of secondary biaryl methanols featuring the use of a slight excess amount of KI (1.2 equivalents, relative to the substrate) in MeOH. 相似文献
106.
A cyclic compound that has alternating diphenylamine and quinodiimine units was obtained by condensation of anthraquinone with bis(4-aminophenyl)amine (aniline dimer) in 20% yield. The resulting macrocycle has an absorption of 462 nm, which is assigned to charge transfer transitions between electron-rich diphenylamine units and electron-poor anthraquinone diimine units. Cyclic voltammetry in acidic MeCN shows redox of anthraquinone diimine units (E(1/2) = 0.03 V vs Ag/Ag(+)) and of oxidation of amino groups of higher potentials (0.60 and 0.77 V). 相似文献
107.
Yano K Sakakibara T Tayama T Yokoyama M Amitsuka H Homma Y Miranović P Ichioka M Tsutsumi Y Machida K 《Physical review letters》2008,100(1):017004
To identify the superconducting gap structure in URu2Si2, we perform field-angle-dependent specific heat measurements for the two principal orientations in addition to field rotations, and a theoretical analysis based on microscopic calculations. The Sommerfeld coefficient gamma(H)'s in the mixed state exhibit a distinctly different field dependence. This comes from point nodes and the substantial Pauli paramagnetic effect of URu2Si2. These two features combined give rise to a consistent picture of superconducting properties, including a possible first order transition of Hc2 at low temperatures. 相似文献