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991.
Derue G Coppée S Gabriele S Surin M Geskin V Monteverde F Leclère P Lazzaroni R Damman P 《Journal of the American Chemical Society》2005,127(22):8018-8019
This work describes a new orientation method for semicrystalline poly(3-hexylthiophene) (P3HT) thin films, coupling nanorubbing and subsequent crystallization. Using the stylus of an atomic force microscope, we align the polymer chains on P3HT surfaces with a spatial and geometrical control of the oriented domains (nanorubbing). These chain-aligned structures can be made permanent thanks to the crystallization process, which propagates the orientation obtained at the surface to the bulk. 相似文献
992.
Two isomeric irregular sesquiterpene aldehydes, namely 3,9-dimethyl-6-isopropyl-2(E),7(E),9-decatrienal and 3,9-dimethyl-6-isopropyl-2(Z),7(E),9-decatrienal, were isolated from the essential oil of Santolina corsica and their structures were elucidated by 1D and 2D NMR spectroscopy. 相似文献
993.
Hamiltonian Stationary Tori in the Complex Projective Plane 总被引:3,自引:0,他引:3
Hamiltonian stationary Lagrangian surfaces are Lagrangian surfacesin a four-dimensional Kähler manifold which are criticalpoints of the area functional for Hamiltonian infinitesimaldeformations. In this paper we analyze these surfaces in thecomplex projective plane: in a previous work we showed thatthey correspond locally to solutions to an integrable system,formulated as a zero curvature on a (twisted) loop group. Herewe give an alternative formulation, using non-twisted loop groupsand, as an application, we show in detail why Hamiltonian stationaryLagrangian tori are finite type solutions, and eventually describethe simplest of them: the homogeneous ones. 2000 MathematicsSubject Classification 53C55 (primary), 53C42, 53C25, 58E12(secondary). 相似文献
994.
Prins P Senthilkumar K Grozema FC Jonkheijm P Schenning AP Meijer EW Siebbeles LD 《The journal of physical chemistry. B》2005,109(39):18267-18274
We have studied the mobility of charge carriers along self-organizing pi-stacks of hydrogen-bonded phenylene vinylene oligomers in solution, by time-resolved microwave conductivity measurements. The value deduced for the mobility along the stacks is 3 x 10(-3) and 9 x 10(-3) cm2/(V s) for holes and electrons, respectively. Additionally, we have calculated the mobility along the pi-stacks using a hopping model based on parameters from density functional theory. The mobility values obtained from these calculations are in good agreement with the experimental values if it is assumed that there are relatively large twist angles between neighboring molecules in the stack. It is shown that a significantly higher mobility can be attained if the twist angle between neighboring oligomers is reduced. 相似文献
995.
996.
997.
Dynamical localization is a localization phenomenon taking place, for example, in the quantum periodically driven kicked rotor. It is due to subtle quantum destructive interferences and is thus of intrinsic quantum origin. It has been shown that deviation from strict periodicity in the driving rapidly destroys dynamical localization. We report experimental results showing that this destruction is partially reversible when the deterministic perturbation that destroyed it is slowly reversed. We also provide an explanation for the partial character of the reversibility. 相似文献
998.
Polymerases form a class of enzymes that act as molecular motors as they move along their nucleic acid substrate during catalysis, incorporating nucleotide triphosphates at the end of the growing chain and consuming chemical energy. A debated issue is how the enzyme converts chemical energy into motion [J. Gelles and R. Landick, Cell 93, 13 (1998)]. In a single molecule assay, we studied how an opposing mechanical force affects the translocation rate of T7 RNA polymerase. Our measurements show that force acts as a competitive inhibitor of nucleotide binding. This result is interpreted in the context of possible models, and with respect to published crystal structures of T7 RNA polymerase. The transcribing complex appears to utilize only a small fraction of the energy of hydrolysis to perform mechanical work, with the remainder being converted to heat. 相似文献
999.
We investigate theoretically the transport properties of two independent artificial Kondo impurities. They are coupled together via a tunable Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction. For strong enough antiferromagnetic RKKY interaction, the impurity density of states increases with the applied in-plane magnetic-field. This effect can be used to distinguish between antiferromagnetic and ferromagnetic RKKY interactions. These results may be relevant to explain some features of recent experiments by Craig et al. [Science 304, 565 (2004)]. 相似文献
1000.
Delqué M Sylvestre T Maillotte H Cambournac C Kockaert P Haelterman M 《Optics letters》2005,30(24):3383-3385
We report the experimental observation of the elliptically polarized fundamental vector soliton of isotropic Kerr media and its unique polarization evolution. This was achieved in the spatial domain in a nonbirefringent CS2 planar waveguide. 相似文献