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1.
We define admissible quasi-Hopf quantized universal enveloping (QHQUE) algebras by ?-adic valuation conditions. We show that any QHQUE algebra is twist-equivalent to an admissible one. We prove a related statement: any associator is twist-equivalent to a Lie associator. We attach a quantized formal series algebra to each admissible QHQUE algebra and study the resulting Poisson algebras. 相似文献
2.
Peixiang Xing Gilles P. Robertson Michael D. Guiver Serguei D. Mikhailenko Serge Kaliaguine 《Journal of polymer science. Part A, Polymer chemistry》2004,42(12):2866-2876
A series of sulfonated poly(aryl ether ketone)s (SPAEKs) were prepared by aromatic nucleophilic polycondensation of 2,6‐dihydroxynaphthalene with 5,5′‐carbonyl‐bis(2‐fluorobenzenesulfonate) and 4,4′‐difluorobenzophenone. The structure and degree of sulfonation (DS) of the SPAEKs were characterized using 1H NMR spectroscopy. The experimentally observed DS values were close to the expected values derived from the starting material ratios. The thermal stabilities of the SPAEKs were characterized by thermogravimetric analysis, which showed that in acid and sodium salt forms they were thermally stable in air up to about 240 and 380 °C, respectively. Transparent membranes cast from the directly polymerized SPAEKs exhibited good mechanical properties in both dry and hydrated states. The dependence of water uptake and of membrane swelling on the DS at different temperatures was studied. SPAEK membranes with a DS from 0.72 to 1.60 maintained adequate mechanical properties after immersion in water at 80 °C for 24 h. The proton conductivity of SPAEK membranes with different degrees of sulfonation was measured as a function of temperature. The proton conductivity of the SPAEK films increased with increased DS, and the highest room temperature conductivity (4.2 × 10?2 S/cm) was recorded for a SPAEK membrane with a DS of 1.60, which further increased to 1.1 × 10?1 S/cm at 80 °C. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2866–2876, 2004 相似文献
3.
D. K. Kuznetsov I. S. Baturin V. Ya. Shur N. Menou C. Muller T. Schneller A. Sternberg 《Physics of the Solid State》2006,48(6):1174-1176
The effect of irradiation with electrons and neutrons and of exposure to synchrotron radiation on cyclic switching of polarization in thin films of lead zirconate titanate Pb(Zr,Ti)O3 (PZT) was studied. It is shown that variations in the shape of switching currents are due to the generation of a spatially nonuniform bound internal field with account for an increase in the rate of bulk screening caused by irradiation. A correlation between structural variations and the evolution of the switching current measured during and after irradiation is established. 相似文献
4.
The synthesis of tocopherol fatty alcohols (TFAs), potent microglial activation modulators, was achieved via C-alkylation of trimethylhydroquinone. Several analogs, in particular water-soluble prodrugs, have been synthesized using a Wittig reaction and their antioxidant activities have been evaluated. 相似文献
5.
6.
In order to replace silicones in some of their biomedical applications, e.g. syringe lubrication, implants ets., a series of digermoxanes (R1R2R3Ge)2O (R = n–alkyl, aryl) were synthesized. These compounds are thermally stable oils; their viscosities, depending on the nature of substituents, lie in the range 1–72 cPo (mPa s) at 20°C. 相似文献
7.
J.-M. Colet C. Piérart F. Seghi I. Gabric R.N. Muller 《Journal of magnetic resonance (San Diego, Calif. : 1997)》1998,134(2):199-205
The relative contributions of intravascular and intracellular compartments to the proton transverse relaxation of the isolated and excised rat liver were determined during the phagocytosis of superparamagnetic particles. The evolution of the proton transverse magnetization of the organ perfused with increasing doses of starch-coated magnetic microspheres was followed up using a Carr–Purcell–Meiboom–Gill sequence with various echo times. From the multiexponential fit of the echo train, the amplitudes and the relaxation ratesR2of the liver tissue were obtained. The results clearly indicate that shortly after contrast medium administration, an internalization takes place which can be followed by the rapid and biphasic evolution of the transverse relaxation rate of the water protons. A very fast decaying component looking like an initial loss of the magnetization is observed together with an increase of the relaxation rate of the remaining water tissue. This regime is strongly dependent on both the echo time and the iron concentration, a behavior characteristic of the agglomeration of magnetic particles. The examination of the liver tissues by electron microscopy shows that this clustering arises in cytoplasmic vacuoles. 相似文献
8.
Anne Boutet De Monvel-Berthier Louis Boutet De Monvel Gilles Lebeau 《Journal d'Analyse Mathématique》1992,58(1):39-60
Sans résumé
Dedicated to Professor Shmuel Agmon 相似文献
9.
Communicated by Charles A. Micchelli. 相似文献
10.
Denis Prat Françoise Benedetti Lahlou Nait Bouda Gilles Franc Girard 《Tetrahedron letters》2004,45(4):765-768
An industrial synthesis of 11β-aryl-estrone derivatives is described, based on the 1,4-addition of the aryl side-chain, as a cuprate, on to a mixture of allylic 5(10) alpha and beta epoxides, followed by hydrolysis and subsequent aromatization. 相似文献