排序方式: 共有19条查询结果,搜索用时 31 毫秒
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Leek PJ Buitelaar MR Talyanskii VI Smith CG Anderson D Jones GA Wei J Cobden DH 《Physical review letters》2005,95(25):256802
We demonstrate charge pumping in semiconducting carbon nanotubes by a traveling potential wave. From the observation of pumping in the nanotube insulating state we deduce that transport occurs by packets of charge being carried along by the wave. By tuning the potential of a side gate, transport of either electron or hole packets can be realized. Prospects for the realization of nanotube based single-electron pumps are discussed. 相似文献
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Heathcote R Howell JA Jennings N Cartlidge D Cobden L Coles S Hursthouse M 《Dalton transactions (Cambridge, England : 2003)》2007,(13):1309-1315
Gold-isocyanide complexes XAu(RNC) (X = halide, pseudohalide, R = alkyl, aryl) and water soluble gold-carbene complexes XAuC(NHPh)[MeN(CH(2)CH(2)O)(n)Me] (X = Cl, n = 1-11) have been prepared and evaluated as substrates for the direct laser writing of gold decoration onto ceramics. 相似文献
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We demonstrate that nonlinear electrical transport through a two-terminal nanoscale sample is not symmetric in the magnetic field B. More specifically, we have measured the lowest order B-asymmetric terms in single-walled carbon nanotubes. Theoretically, these terms can be used to infer both the strength of electron-electron interactions and the handedness of the nanotube. Consistent with theory, we find that at high temperatures the B-linear term is small and has a constant sign independent of Fermi energy, while at low temperatures it develops mesoscopic fluctuations. We also find surprising magnetoresistance at zero bias in the metallic regime. 相似文献
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Localization of carboxyl groups at surface layer of carboxylated polymer emulsion particles by alkali treatment 总被引:1,自引:0,他引:1
For the purpose of localizing carboxyl groups from inside to particle surface, styrene — butyl acrylate — methacrylic acid (74.3/17.0/8.7, mol ratio) terpolymer emulsion was kept under pH 9 at different temperatures. The amount of carboxyl groups at the particle surface, As, was remarkably increased by the alkali-treatment above 35 °C. On the other hand, As value of the alkalitreated emulsion was decreased by keeping under ph 3 above 45 °C, although in the case of the original emulsion without the alkalitreatment, it was not changed by the acid-treatment. These results suggest that a part of polymer segments which have ionized carboxyl groups is dragged out at the surface by an increase in the affinity of the groups against water, and the dragged segments turn back into the inside again when the carboxyl groups are deionized.Part 97 of the series Studies on Suspension and Emulsion. 相似文献
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Skeletons and Central Sets 总被引:1,自引:0,他引:1
Let be an open proper subset of Rn. Its skeleton is the setof points with more than one nearest neighbour in the complementof its central set is the set of centres in maximal open ballsincluded in . Intuitively, if we think of as a land mass inwhich height is proportional to distance from the sea, its skeletonand central set can be thought of as corresponding to ridgesin the mountains of . In this note I discuss the metric andtopological properties of such sets. I show that any skeletonin Rn is F, and has dimension at most n 1, by any ofthe usual measures of dimension; that if is bounded and connected,its skeleton and central set are connected; and that separatesRn iff its skeleton does iff its central set does. Any centralset in Rn is a G set of topological dimension at most n 1. In the plane, I show that both skeletons and central setsare locally path-connected, and indeed include many paths offinite length. For any , its central set includes its skeleton;I give examples to show that the central set can be significantlylarger than the skeleton. 1991 Mathematics Subject Classification:54F99. 相似文献
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Buitelaar MR Kashcheyevs V Leek PJ Talyanskii VI Smith CG Anderson D Jones GA Wei J Cobden DH 《Physical review letters》2008,101(12):126803
We investigate charge pumping in carbon nanotube quantum dots driven by the electric field of a surface acoustic wave. We find that, at small driving amplitudes, the pumped current reverses polarity as the conductance is tuned through a Coulomb blockade peak using a gate electrode. We study the behavior as a function of wave amplitude, frequency, and direction and develop a model in which our results can be understood as resulting from adiabatic charge redistribution between the leads and quantum dots on the nanotube. 相似文献