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981.
Sergei F. Lyuksyutov Mindaugas RackaitisVictoria Nedashkivska 《Applied Surface Science》2011,257(10):4581-4585
A nanolithography technique based on the lateral displacement of electrically biased AFM tip was developed for nanostructures formation of 30-100 nm in width and 1-10 nm in height in the polystyrene (PS) films. It was demonstrated that the nanostructures patterned in annealed PS films (90K Mw) show slow exponential relaxation between 55 and 265 h depending on their size. Relaxation of the nanostructures in non-annealed films usually occurred in minutes. It was observed that in the annealed samples a negative electric charge accumulated in the areas where the nanostructures formed while in the non-annealed samples only the positive charge in exposed areas was detected using the electric force microscopy. After 320 h of monitoring under the humidity maintained between 25 and 27% it was suggested that slow dynamical changes of the nanostructures can be attributed to the negative electric charge dissipation in the annealed samples. 相似文献
982.
We study refined and motivic wall-crossing formulas in N=2{{\mathcal N}=2} supersymmetric gauge theories with SU(2) gauge group and N
f
< 4 matter hypermultiplets in the fundamental representation. Such gauge theories provide an excellent testing ground for
the conjecture that “refined = motivic.” 相似文献
983.
To every 3-manifold M one can associate a two-dimensional ${\mathcal{N}=(2, 2)}$ supersymmetric field theory by compactifying five-dimensional ${\mathcal{N}=2}$ super-Yang?CMills theory on M. This system naturally appears in the study of half-BPS surface operators in four-dimensional ${\mathcal{N}=2}$ gauge theories on one hand, and in the geometric approach to knot homologies, on the other. We study the relation between vortex counting in such two-dimensional ${\mathcal{N}=(2, 2)}$ supersymmetric field theories and the refined BPS invariants of the dual geometries. In certain cases, this counting can also be mapped to the computation of degenerate conformal blocks in two-dimensional CFT??s. Degenerate limits of vertex operators in CFT receive a simple interpretation via geometric transitions in BPS counting. 相似文献
984.
Continuous-wave (CW) electron paramagnetic resonance (EPR) and echo-detected (ED) EPR spectra of triplet state of fullerene
C70 in molecular glasses of decalin, o-terphenyl and toluene, and in polymethylmethacrylate polymer were obtained under continuous light illumination. Temperature
was high enough so that the EPR spectra corresponded to thermal equilibrium between the spin sublevels. The comparison of
CW EPR and ED EPR data has shown that pseudorotation in the 3C70 frame does not remarkably affect deriving the zero-field splitting (ZFS) D and E parameters from the EPR spectra. 3C70 EPR spectra were simulated at 77 K fairly well using the distribution of the ZFS D and E parameters. These distributions may be caused by the inhomogeneity of the glassy matrix surrounding, which affects the Jahn–Teller
distortions of 3C70 molecules (D-strain and E-strain). 相似文献
985.
Sergei M. Pimenov Vadim D. Frolov Evgeny V. Zavedeev Nikolay P. Abanshin He-Yun Du Wei-Chao Chen Li-Chyong Chen Jih-Jen Wu Kuei-Hsien Chen 《Applied Physics A: Materials Science & Processing》2011,105(1):11-16
In this paper, we have studied field emission properties of highly dense arrays of multi-walled carbon nanotubes (CNTs) used
as cathodes in diode-type field emission devices with a phosphor screen. For the high-density CNT emitters it is demonstrated
that the emission sites are located on the CNT-cathode edges, which is direct experimental evidence of the ‘edge effect’.
The results of computer simulations (using ‘ANSYS Electromagnetic’ software) are presented to confirm the experimental data
and to analyze the effect of patterning on the electric field distribution for high-density CNT arrays. It is shown that selective-area
removal of nanotubes in the arrays leads to the formation of additional edges characterized by the high field enhancement
factor and enhanced emission from the CNT cathodes. In addition, scanning probe microscopy techniques are employed to examine
surface properties of the high-density CNT arrays. For CNT arrays of ‘short’ nanotubes, the work function distribution over
the sample surface is detected using a scanning Kelvin microscopy method. 相似文献
986.
987.
Jozak T Sun Y Schmitt Y Lebedkin S Kappes M Gerhards M Thiel WR 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(12):3384-3389
The treatment of 2,2'-di(1,2-pyrazol-3-yl)-1,1'-binaphthyl with two equivalents of appropriate monovalent group 11 precursors in the presence of a base leads to a complete exchange of the pyrazole NH protons with M(+) cations. Structural characterisation of the copper(I) complex revealed a hexanuclear complex with a pelton-wheel-like arrangement of the binaphthyl unit. As indicated by their spectroscopic data, all three complexes are isostructural. The complexes show a complex fluorescence behaviour that can be partially related to the ligand system and also to the metal sites, as indicated by the position of the fluorescence peaks and their temperature dependence and lifetimes. 相似文献
988.
989.
We study Finsler PL spaces, that is simplicial complexes glued out of simplices cut off from some normed spaces. We are interested in the class of Finsler PL spaces featuring local uniqueness of geodesics (for complexes made of Euclidean simplices, this property is equivalent to local CAT(0)). Though non-Euclidean normed spaces never satisfy CAT(0), it turns out that they share many common features. In particular, a globalization theorem holds: in a simply-connected Finsler PL space local uniqueness of geodesics implies the global one. However the situation is more delicate here: some basic convexity properties do not extend to the PL Finsler case. 相似文献
990.
Sergei Sverchkov 《代数通讯》2013,41(2):886-908
We construct a polynomial of degree 5 from the associative nucleus (kernel) of the free alternative algebra. We show that this polynomial is of minimal degree. Using this polynomial, we obtain decompositions of the varieties of alternative and Malcev algebras. 相似文献