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191.
Kaoru Nakajima Shinichi Oshima Motofumi Suzuki Kenji Kimura 《Surface science》2012,606(21-22):1693-1699
Surface structures of equimolar mixtures of imidazolium-based ionic liquids (ILs) having a common cation (1-butyl-3-methylimidazolium ([C4MIM]) or 1-hexyl-3-methylimidazolium ([C6MIM])) and different anions (bis(trifluoromethanesulfonyl)imide ([TFSI]), hexafluorophosphate ([PF6]) or chlorine) are studied using high-resolution Rutherford backscattering spectroscopy (HRBS). Both cations and anions have the same preferential orientations at the surface as in the pure ILs. In the mixture, the larger anion is located shallower than the smaller anion. The [TFSI] anion is slightly enriched at the surface relative to [PF6] with coverage of ~ 60% for the equimolar mixtures of [C4(6)MIM] [TFSI] and [C4(6)MIM] [PF6]. No surface segregation is observed for [C6MIM] [TFSI]0.5[Cl]0.5 and [C6MIM] [PF6]0.5[Cl]0.5. These results are different from the recent TOF-SIMS measurement where very strong surface segregation of [TFSI] was concluded for the mixture of [C4MIM] [TFSI] and [C4MIM] [PF6]. 相似文献
192.
Thomas Yorisaki Aashani Tillekaratne Yuan Ren Yukihiro Moriya Chuhei Oshima Shigeki Otani Michael Trenary 《Surface science》2012,606(3-4):247-252
The chemisorption of water (H2O and D2O) on a LaB6(100) surface was studied with reflection absorption infrared spectroscopy (RAIRS) and high resolution electron energy loss spectroscopy (HREELS). The clean surface was exposed to H2O and D2O at temperatures from 90 K to room temperature, and spectra were acquired after heating to temperatures as high as 1200 K. It was found that water molecularly adsorbs on the surface at 90 K as a monomer at low coverages and as amorphous solid water at higher coverages. Water adsorbs dissociatively at room temperature to produce surface hydroxyl species as indicated by OH/OD stretch peaks at 3676/2701 cm?1. Room temperature adsorption also reveals low frequency loss features in HREEL spectra near 300 cm?1 that are quite similar to results obtained following the dissociative adsorption of O2. In the latter case, the loss features were attributed to the LaO stretch of O atoms bridge-bonded between two La atoms. In the case of dissociative adsorption of H2O, the low frequency loss features could be due to either the LaO vibrations of adsorbed O or of adsorbed OH. 相似文献
193.
194.
Tatsuya Oshima Yoshinari Baba 《Journal of inclusion phenomena and macrocyclic chemistry》2012,73(1-4):17-32
Artificial ligands for recognition of exterior protein surfaces can be used for protein detection, protein modification/modulation, and protein separation. This article reviews recent developments of artificial ligands for complexation with exterior protein surfaces, with a focus on studies using calixarene-, crown ether-, and tetraphenylporphyrin-based ligands. Synthetic ligands that recognize amino acid residues can form n:1 supramolecules with proteins. 18-Crown-6 and calix[6]arene derivatives have been used for complexation with the lysine residues of proteins. By comparison, larger ligands that have a central core and multivalent functionalities at the periphery can form 1:1 supramolecules with proteins. 相似文献
195.
Kinetic study of the reactions of diphenyldiazomethane with various electron acceptors were made in six aromatic solvents. Log k were correlated with the solvent basicity parameter, Dπ, and the regression slopes were found to be a function of electron affinities. 相似文献
196.
Hiroji Oda Mitsuyoshi Sato Yoshitomi Morizawa Koichiro Oshima Hitosi Nozaki 《Tetrahedron》1985,41(16):3257-3268
Dimethylphenylsilyl group is removed from a vinyl carbon with tetrabutylammonium fluoride. The presence of phenyl group on silicon atom plays a critical role. The cleavage of allyldimethylsilyl- and alkoxydimethylsilyl groups also proceeds very easily. 相似文献
197.
张玉虎 M.Oshima T.Morikawa T.Hayakawa Y.Toh 周小红 何建军 刘忠 甘再国 T.Shizuma M.Koizumi A.Osa J.Katakura Y.Hatsukawa M.Matsuda N.Shinohara T.Ishii H.Kusakari M.Sugawara K.Furuno T.Komatsubara T.Une 温书贤 竺礼华 王治民 许甫荣 《中国物理 C》2003,(4)
利用重离子熔合蒸发反应和在束γ谱学实验方法研究了双奇核176,178Ir和182 Au的高自旋态结构 ,在这 3个双奇核中观测到了基于πi13 2 νi13 2 准粒子组态下的转动带 .以能级间隔系统学为判据 ,对184Au核中πi13 2 νi13 2 转动带能级自旋进行了指定 .指出176,178Ir和182 ,184Au 4个双奇核的πi13 2 νi13 2 转动带在低自旋区均出现旋称反转 .对πi13 2 νi13 2 转动带旋称反转现象进行了定性的讨论 .用推转壳模型对πh9 2 νi13 2 带和πi13 2 νi13 2 带能级结构进行了理论研究 ,发现当采用形变和对力自洽计算后 ,从理论上可以定性地解释两个半退耦带出现的旋称反转现象 相似文献
198.
Haruyasu Asahara Takuya Koizumi Eiko Mochizuki Takumi Oshima 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(3):o136-o138
The crystal structures of the two thermally equilibrated conformational isomers of the epoxide 1′,5′‐dimethylspiro[10,11‐dihydro‐5H‐dibenzo[a,d]cycloheptene‐5,8′‐4′‐oxatricyclo[5.1.0.03,5]octane]‐2′,6′‐dione, C23H20O3, have been determined by X‐ray diffraction. In the tricyclic dione skeleton, the oxirane and cyclopropane rings adopt an anti structure with respect to the conjunct quinone frame. The spiro‐linked 10,11‐dihydro‐5H‐dibenzo[a,d]cycloheptene ring of the major isomer has a fairly twisted boat form, folding opposite to the adjoining cyclopropane methyl substituent, whereas the seven‐membered ring of the minor isomer has an almost ideal twist–boat form, inversely folding to the side of the relevant methyl group. The conformational structures of these isomers have been compared with those of the corresponding isomers of the unepoxidized homobenzoquinone. 相似文献
199.
Tatsuya Oshima Akinori Suetsugu Yoshinari Baba Yuka Shikaze Keisuke Ohto Katsutoshi Inoue 《Journal of membrane science》2008
The present study examined the liquid membrane transport of the cationic protein cytochrome c, using the macrocyclic compound calix[6]arene, which is a carboxylic acid derivative, as a carrier. The transport rate was governed by carrier concentration and the pH gradient between the feed and the receiving phases, as well as the salt concentration in the aqueous phases. Transport of cytochrome c was examined using a series of calix[n]arene carboxylic acid derivatives (n = 4, 6 and 8). Cytochrome c successfully permeated membranes in the presence of the calix[6]arene derivative. Liquid membrane separation of cytochrome c from a mixture of cationic proteins was demonstrated under optimal conditions. Cytochrome c was selectively extracted by the calix[6]arene carboxylic acid derivative and 77% of the extracted cytochrome c was recovered into the receiving phase. In this liquid membrane system, which discriminates between the number of lysine residues on the surface of proteins, cationic proteins with similar molecular weights and pIs were separated with macrocyclic compounds. 相似文献
200.
Toshiyuki Taniuchi Hiroshi Kumigashira Masato Kubota Takanori Wakita Takanori Yokoya Kanta Ono Masaharu Oshima Mikk Lippmaa Hideomi Koinuma 《Surface science》2007,601(20):4690-4693
We have used photoelectron emission microscopy (PEEM) and X-ray magnetic circular dichroism (XMCD) to study the effect of thin film thickness on the magnetic domain formation in La0.6Sr0.4MnO3 samples that were epitaxially grown on stepped SrTiO3 (0 0 1) substrates. The magnetic image exhibited a stripe structure elongated along the step direction, irrespective of film thickness, suggesting that uniaxial magnetic anisotropy induced by step-and-terrace structures plays an important role in the magnetic domain formation. Additional domains evolved gradually with increasing film thickness. In these domains, the direction of magnetization differed from the step direction due to biaxial magneto-crystalline anisotropy. The evolution of additional magnetic domains with increasing film thickness implies that a competition exists between the two anisotropies in LSMO films. 相似文献