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971.
Microwave-assisted synthesis and electrochemical capacitance of polyaniline/multi-wall carbon nanotubes composite 总被引:1,自引:0,他引:1
Hongyu Mi Xiaogang Zhang Shuying An Xiangguo Ye Sudong Yang 《Electrochemistry communications》2007,9(12):2859-2862
Polyaniline/multi-wall carbon nanotubes composite (PANI/MWNTs) was rapidly synthesized by microwave-assisted polymerization. Transmission electron microscope (TEM) image revealed that this composite was a core–shell structure with PANI layers (50–70 nm). Electrochemical behavior of the composite was evaluated by cyclic voltammetry (CV) and galvanostatic charge–discharge tests with a two-electrode system. An enhanced specific capacitance of 322 F/g with a specific energy density of 22 W h/kg was about 12 times that of MWNTs. This composite also exhibited a good rate capability, retaining up to 87% of initial capacity at a current density of 5 mA/cm2. 相似文献
972.
Nguyen Thieu Huy 《Journal of Mathematical Analysis and Applications》2007,333(2):731-752
In this paper we investigate the exponential dichotomy of linear skew-product semiflows over semiflows by considering the operators generated by the integral equation related to strongly continuous cocycles over metric spaces acting on Banach bundles. We characterize the existence of exponential dichotomy by properties of these operators and use this characterization to prove the robustness of exponential dichotomy. 相似文献
973.
Several new ferroelectric liquid crystals with thiobenzoate mesogenic cores have been synthesized and the influence of a single fluorine atom ortho to the alkyloxy tail on the mesomorphic properties of some two and three benzene ring core compounds has been studied. The two benzene ring derivatives do not display the ferroelectric smectic C phase but the three phenyl ring compounds exhibit a wide temperature range Sc* phase. The transition temperatures and enthalpies of transition for these compounds have been determined; the spontaneous polarization, response time and tilt angle have also been measured and are discussed as a function of the structure near to the chiral centre. 相似文献
974.
Nguyen Tien Zung 《Compositio Mathematica》2003,138(2):125-156
The main purpose of this paper is to give a topological and symplectic classification of completely integrable Hamiltonian systems in terms of characteristic classes and other local and global invariants. 相似文献
975.
Nguyen Quang VuDanielle Grée René GréeEric Brown Gilles Dujardin 《Tetrahedron letters》2003,44(34):6425-6428
Reaction of polysubstituted 2-hydroxyalkyldihydropyrans with DAST led regiospecifically to fluorination at the exocyclic position, except for primary alcohols. Difluorination of carbonylated analogues with deoxo-fluor™ occurred also regioselectively. The unexpected stability and synthetic potential of these new allylic fluorides are discussed. 相似文献
976.
Nguyen Buong 《Computational Mathematics and Mathematical Physics》2007,47(10):1583-1588
The goal of this study is to analyze the Tikhonov regularization method as applied to a general nonlinear optimization problem
that has been previously reduced to an unconstrained optimization problem. The stability properties of the method are examined,
and its convergence is proved.
The text was submitted by the author in English. 相似文献
977.
978.
Tran Dan Thu 《Journal of Combinatorial Theory, Series A》2007,114(8):1504-1514
The powerful AZ identity is a sharpening of the famous LYM-inequality. More generally, Ahlswede and Zhang discovered a generalization in which the Bollobás inequality for two set families can be lifted to an identity.In this paper, we show another generalization of the AZ identity. The new identity implies an identity which characterizes the deficiency of the Bollobás inequality for an intersecting Sperner family. We also give some consequences relating to Helly families and LYM-style inequalities. 相似文献
979.
Layered γ-Zirconium phosphate (γ-ZrP) preintercalated with butylamine,tetra(n-butylammonium)hydroxide,dimethylamine respectively,or only ultrasonificated,for preparation of immobilized hemoglobin were in vestigated in this report. 相似文献
980.
De‐Xi Yang Shu‐An Li Dong‐Feng Li Wen‐Xia Tang 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o11-o13
A novel binucleating 24‐membered macrocyclic ligand, 6,20‐bis(2‐hydroxyethyl)‐3,6,9,17,20,23‐hexazatricyclo[23.3.1.111,15]triaconta‐1(29),11(30),12,14,25,27‐hexaene (L), was synthesized and crystallized as the tetrahydrobromide salt, i.e. 6,20‐bis(2‐hydroxyethyl)‐6,20‐diaza‐3,9,17,23‐hexaazoniatricyclo[23.3.1.111,15]triaconta‐1(29),11(30),12,14,25,27‐hexaene tetrabromide tetrahydrate, C28H50N6O24+·4Br?·4H2O. A crystallographic inversion center is located in the macrocyclic cavity and the two hydroxyethyl pendants are on opposite sides of the macrocyclic plane. The benzene rings of the macrocycle are parallel to each other and a π–π‐stacking interaction exists between the benzene rings of adjacent macrocycles, which are separated by 3.791 (9) Å. An infinite intermolecular hydrogen‐bond network stabilizes the crystal. 相似文献