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31.
32.
Jari M. Kinaret Mats Jonson Robert I. Shekhter Sebastian Eggert 《Physica E: Low-dimensional Systems and Nanostructures》1998,1(1-4)
We consider a mesoscopic ring connected to external reservoirs by tunnel junctions. The ring is capacitively coupled to an external gate electrode and may be pierced by a magnetic field. Due to strong electron–electron interactions within the ring the conductance shows Coulomb blockade oscillations as a function of the gate voltage, while Aharonov–Bohm interference effects lead to a dependence on the magnetic flux. The Hamiltonian of the ring is given by a Luttinger model that allows for an exact treatment of both interaction and interference effects. We conclude that the positions of conductance maxima as a function the external parameters can be used to determine the interaction parameter
, and the shapes of conductance peaks are strongly affected by electron correlations within the ring. 相似文献
33.
I. Tittonen J. Hietaniemi J. Huttunen E. Ikonen M. Karppinen T. Katila J. Lindén L. Niinistö 《Hyperfine Interactions》1990,55(1-4):1399-1403
Both57Fe and151Eu Mössbauer resonances were used to study polycrystallineRBa2Cu3O7-δ samples. The dependence of hyperfine interaction parameters on the oxygen deficiency δ is studied in detail with151Eu. For57Fe spectra, a site assignment is proposed. 相似文献
34.
Giuseppe Cardone Sergey A. Nazarov Jan Sokolowski Jari Taskinen 《Comptes Rendus Mecanique》2007,335(12):763-767
We construct the asymptotics (as ε→0) of solutions to the Neumann problem for the Laplace equation and of the corresponding Dirichlet integral. The problem concerns a three-dimensional domain having two connected components of the boundary at the distance ε>0. To cite this article: G. Cardone et al., C. R. Mecanique 335 (2007). 相似文献
35.
Williams DH Davies NL Koivisto JJ 《Journal of the American Chemical Society》2004,126(43):14267-14272
Two models (A and B) have been proposed to account for decreased downfield chemical shifts of a proton bound by noncovalent interactions at a ligand/antibiotic interface as the number of ligand/antibiotic interactions is decreased. In model A, the proton involved in the noncovalent bond suffers a smaller downfield shift because the bond is, with a relatively large probability, broken, and not because it is longer. In model B, the proton involved in the noncovalent bond suffers a smaller downfield shift because the bond is longer, and not because it is, with a relatively large probability, broken. We show that model A cannot account for the chemical shift changes. Model B accounts for the process of positively cooperative binding, in which noncovalent bonds are reduced in length and thereby increase the stability of the organized state. 相似文献
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Jyrki K. Kauppinen Ilkka K. Salomaa Jari O. Partanen Matti R. Hollberg 《Optical Review》1997,4(2):293-296
The carousel interferometer is a new type of an interferometer, which has been invented at the University of Turku. It consists of a beamsplitter and five plane mirrors. Four of the mirrors are mounted on a carousel, which rotates back and forth. We have modified the interferometer for use in the Fourier-transform ultraviolet (FT-UV) spectroscopy. Test measurement with plasma radiation gives favourable results. The most important property, which makes the carousel interferometer suitable for UV measurements, is its good stability in modulation.Presented at 1996 International Workshop on Interferometry (IWI ‘96), August 27–29, Saitama, Japan. 相似文献
38.
Janne Martikainen Tuomo Rossi Jari Toivanen 《Numerical Linear Algebra with Applications》2002,9(8):629-652
A fast direct solution method for a discretized vector‐valued elliptic partial differential equation with a divergence constraint is considered. Such problems are typical in many disciplines such as fluid dynamics, elasticity and electromagnetics. The method requires the problem to be posed in a rectangle and boundary conditions to be either periodic boundary conditions or the so‐called slip boundary conditions in one co‐ordinate direction. The arising saddle‐point matrix has a separable form when bilinear finite elements are used in the discretization. Based on a result for so‐called p‐circulant matrices, the saddle‐point matrix can be transformed into a block‐diagonal form by fast Fourier transformations. Thus, the fast direct solver has the same structure as methods for scalar‐valued problems which are based on Fourier analysis and, therefore, it has the same computational cost ??(N log N). Numerical experiments demonstrate the good efficiency and accuracy of the proposed method. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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Salminen JP Karonen M Lempa K Liimatainen J Sinkkonen J Lukkarinen M Pihlaja K 《Journal of chromatography. A》2005,1077(2):170-180
Fifteen individual proanthocyanidin aglycones and 19 glycosides, together with a complex mixture of chromatographically non-separated tetra- to octameric proanthocyanidin glycosides were detected--the non-separated glycosides being novel natural products--and characterised from dog rose hips using high-performance liquid chromatography-electrospray ionisation mass spectrometry (HPLC-ESI-MS). Along with these phenolics, a 50% aqueous ethanol extract of rose hips was found to contain high levels of Vitamin C. A simple and rapid HPLC method assisted by diode array detection for the estimation of the total concentration of proanthocyanidin aglycones and glycosides, as well as Vitamin C, in rose hip extracts was developed. 相似文献