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71.
Toshinobu?YogoEmail author Reimon?Fukuzawa Wataru?Sakamoto Shin-ichi?Hirano 《Journal of nanoparticle research》2005,7(6):633-640
Nanocrystalline BaTiO3 particles modified with polarizable ligands were synthesized through hydrolysis of modified metal–organics below 100°C. BaTiO3 precursor was synthesized from barium metal, titanium isopropoxide and polarizable ligands in a mixture of ethanol and 2-ethoxyethanol.
The modified Ba–Ti complex alkoxide was hydrolyzed yielding BaTiO3 particles modified with organics. The crystallinty of nanometer-sized particles was dependent upon the hydrolysis conditions,
and increased with increasing water amount and time. The nanocrystalline particles were identified to be BaTiO3 by X-ray diffraction (XRD) and electron diffraction. A fluid consisting of modified BaTiO3 particles and silicone oil revealed a typical electrorheological (ER) behavior on applying DC field. The ER behavior was
found to depend upon the kind of ligand. 4-Fluorobenzyloxy modifier revealed the highest yield stress in the ER measurement
among 4-substitued benzyloxy ligands examined. 相似文献
72.
Muramatsu Y Ueda K Saito N Chiba H Lavollée M Czasch A Weber T Jagutzki O Schmidt-Böcking H Moshammer R Becker U Kubozuka K Koyano I 《Physical review letters》2002,88(13):133002
The doubly degenerate core-excited Pi state of CO2 splits into two due to static Renner-Teller effect. Using the triple-ion-coincidence momentum imaging technique and focusing on the dependence of the measured quantities on the polarization of the incident light, we have probed, directly and separately, the linear and bent geometries for the B1 and A1 Renner-Teller pair states, as a direct proof of the static Renner-Teller effect. 相似文献
73.
74.
It is shown that a square invariant of the Weyl conformal curvature tensor can lead to a Lagrangian in a variational principle for a gravitational equation in vacuum of the Bianchi identity type which is compatible with the Einstein equation. Moreover we show that such a Lagrangian implicitly includes a conformally invariant theory characterized by two gauge fields and the metric tensor. 相似文献
75.
76.
Ueda K Tanaka S Shimizu Y Muramatsu Y Chiba H Hayaishi T Kitajima M Tanaka H 《Physical review letters》2000,85(15):3129-3132
The Auger emission following the resonant excitation of the BCl3 molecule has been investigated using monochromatized synchrotron radiation. The B 1s excitation to the unoccupied Anti-bonding 4e(') orbital enhances the shoulder structure in the low kinetic energy side of the photoemission from the 2e(') valence bonding orbital. Based on a series of quantum mechanical calculations, this shoulder structure is interpreted as the dynamical Auger emission which reflects the B-Cl stretching nuclear motion and appears as a result of the purely multistate vibronic coupling effect among the Jahn-Teller split B 1s(-1)4e(') E' states and the closely lying B 1s(-1)3a(')(1) A'1 state. 相似文献
77.
The effect of pH on the molecular shape and dispersed state of native ovalbumin molecules in 20 mM phosphate and acetic acid buffer solutions has been studied using small-angle x-ray scattering (SAXS) and a rheological method The degree of association of the OA molecule at the 0.5% colloid system increases slightly with decreasing pH, i.e., 2.10 at pH 7.0, and 2.88 at pH 4.0, and the radius of the OA molecule decreases slightly with decreasing pH, i.e., 24.5 Å at pH 7.0, and 22.0 Å at pH 4.0.The OA colloid shows apparent yield stress and rigidity which are due to a certain ordered arrangement of the molecules. The yield stress and the rigidity increase abruptly at a pH value near to an isoelectric point (ca. pH 4.4). In the dilute system this increment is attributed to the change in the ordered arrangement or in the interparticle interaction, and not to the change in the association state of the OA molecules. The values of the yield stress and the rigidity remain almost constant over a wide concentration range and this feature (an auto-controlled mechanism) is kept over a certain range of pH. 相似文献
78.
Hideo Nishii Toshinobu Higashimura 《Journal of polymer science. Part A, Polymer chemistry》1977,15(5):1179-1188
Ring-substituted methylstyrenes (p-, m-, and o-methylstyrenes) in conjunction with acetyl perchlorate (AcClO4) or trifluoromethanesulfonic acid as catalysts gave their linear unsaturated dimer in high yield in benzene at temperatures from 50 to 70°C. In particular, the yield of o-methylstyrene dimer was as high as 90% in the AcClO4 catalysis at 50°C. The dimer yield depended on solvent and catalyst. The terminal structures of the dimers and higher oligomers were analyzed by NMR spectroscopy. Oligomers with a cyclic terminal structure increased in the products at higher temperature. The dimer yield was improved by codimerizing p-methylstyrene with less reactive m-methylstyrene or styrene with AcClO4 catalyst. The dimers obtained partly consisted of linear unsaturated codimers. 相似文献
79.
Shokyoku Kanaoka Nobuyuki Ikeda Akira Tanaka Hitoshi Yamaoka Toshinobu Higashimura 《Journal of polymer science. Part A, Polymer chemistry》2002,40(14):2449-2457
Random copolymers with high molecular weights of indene and p‐methylstyrene (pMeSt) were synthesized by cationic polymerization with trichloroacetic acid/tin tetrachloride in CH2Cl2 at low temperatures. When indene and pMeSt (1:1 v/v), for example, were polymerized at ?40 °C, both monomers were consumed at very similar rates to give a copolymer with high molecular weight [number‐average molecular weight (Mn): 8–9 × 104]. This is indeed quite unexpected behavior for the combination of these two monomers because pMeSt polymerized over 1000 times faster than indene in the homopolymerization under the reaction conditions previously described. The product copolymer of indene and pMeSt had a random monomer sequence in it that was confirmed by NMR analyses and thermal‐property measurements. In sharp contrast with pMeSt, styrene and p‐chlorostyrene, which have no electron‐donating groups on the phenyl ring, led to low molecular weight polymers (Mn < 10,000) in the copolymerization with indene (1:1 v/v). © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2449–2457, 2002 相似文献
80.
Shin-ichi Hirano Toshinobu Yogo Wataru Sakamoto Seiji Yamada Tomoyuki Nakamura Tomoe Yamammto Hiroyuki Ukai Kouichi Banno Tomoko Nakafuku Yukari Ando 《Journal of Sol-Gel Science and Technology》2003,26(1-3):35-41
Nano sized crystalline particles/polymer hybrids were synthesized form designed metal-organic precursors. The newly developed method is composed of the synthesis of organic matrix by polymerization and the in situ nucleation and growth of crystalline oxide particles in the organic matrix below 100°C. The design of metal-organic precursor modified with polymerizable ligand and the selection of reaction conditions does influence the size and crystallinity of ceramic particles in organic matrix. The nano-sized magnetic particle/polymer hybrid exhibits the interesting feature of superparamagnetism and quantum size effect. The crystalline particles of BaTiO3/, PbTiO3/, and KNbO3/polymer hybrids behave to be dielectric and show the typical electro-rheological behavior. 相似文献