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41.
A. V. Solnyshkin M. Wegener W. Künstler R. Gerhard-Multhaupt 《Physics of the Solid State》2008,50(3):562-567
The temperature dependences of the real and imaginary parts of the complex permittivity of vinylidene fluoride-trifluoroethylene copolymer films at temperatures ranging from ?40 to 140°C are determined in the frequency range 10?1–108 Hz. An analysis of the experimental data has demonstrated that the behavior of the dielectric characteristics of the copolymer in the course of heating to temperatures above the ferroelectric phase transition point and during subsequent cooling differs substantially. In the latter case, the high-frequency dielectric response exhibits properties characteristic of relaxor ferroelectrics. The observed features are discussed in terms of the competition of two mechanisms associated with the short-range and long-range forces. 相似文献
42.
Finitely generated free modular ortholattices. II 总被引:2,自引:0,他引:2
M. Haviar P. Konôpka C. B. Wegener 《International Journal of Theoretical Physics》1997,36(12):2661-2679
43.
Mikael Krysell Roland Becker Jan Willem Wegener Hans-Gerhard Buge 《Accreditation and quality assurance》2008,13(10):553-562
As an answer to the re-evaluation of the European sludge directive, two novel reference materials for organic components in
municipal sludge have been produced and test certified for AOX (absorbable organic halogens), PAH (polycyclic aromatic hydrocarbons),
NPE (nonylphenol and nonylphenolethoxylates), DEHP (di(2-ethylhexyl)phthalate), bisphenol A, and BFR (brominated flame retardants).
The materials were prepared from raw sludge without spiking or mixing of different sludges. The study demonstrated that the
technique for the preparation of a suitable reference material, sufficiently homogenous and stable, and with concentration
levels that answer the needs of the laboratories and the relevant authorities, can now be presented in detail. The results,
furthermore, show there is a need for method validation and standardisation of the measurements of NPEs and certain BFR congeners,
and that the development of the laboratory structure in Europe, with fewer and more specialised laboratories, might become
a major obstacle when trying to find a sufficient number of laboratories being appropriately proficient for this kind of study
in the future. 相似文献
44.
45.
N. E. Kotelnikova E. F. Panarin R. Serimaa T. Paakkari G. Wegener E. Windeisen 《Macromolecular Symposia》1999,138(1):181-189
In order to obtain multicomponent polymer systems exhibiting biological activity microcrystalline cellulose was used as a matrix for biologically active compounds, such as dimethylbenzylalkylammonium chloride, poly-N-vinylpyrrolidone, copolymer of N-vinylpyrrolidone and crotonic acid, and complex of dimethylbenzylalkylammonium chloride with copolymer of N-vinylpyrrolidone and crotonic acid. Adsorption interaction of microcrystalline cellulose with these was studied under various conditions. Adsorption isotherms of compounds of polymer nature are of similar character and are described by the Freundlich equation. The isotherms of dimethylbenzylalkylammonium chloride are described by the Langmuir equation. Characteristics of the resulting compounds were obtained using XPS and IR Fourier spectroscopy, WAXS, and SEM. Chemical interaction between microcrystalline cellulose and dimethylbenzylalkylammonium chloride takes place. This interaction leads to a new labile morphological cellulose structure accessible to penetration, which is confirmed at a morphological level by SEM. 相似文献
46.
C. E. Kriegler M. S. Rill M. Thiel E. Müller S. Essig A. Fr?lich G. von Freymann S. Linden D. Gerthsen H. Hahn K. Busch M. Wegener 《Applied physics. B, Lasers and optics》2009,96(4):749-755
We fabricate split-ring-resonator arrays via direct laser writing of polymers, followed by atomic-layer deposition of titania,
chemical vapor deposition of silver, and focused-ion-beam milling. While structures like that have been fabricated previously
by other means, our approach here allows for a direct comparison with the optical properties of corrugated metal surfaces,
which are fabricated along the same lines. This comparison reveals substantial differences regarding the magnetic metamaterial
properties. In particular, we find that the optical response of the corrugated metal surfaces is due to a higher-order magnetic
resonance, whereas that of the split-ring resonators stems from their fundamental magnetic resonance. 相似文献
47.
Joachim Wegener 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2009,121(16):2867-2868
Spektrum Akademischer Verlag, Heidelberg 2008. 284 S., geb., 34.95 €.—ISBN 978‐3827418319
48.
Sapper A Reiss B Janshoff A Wegener J 《Langmuir : the ACS journal of surfaces and colloids》2006,22(2):676-680
The present study describes a novel approach based on electrochemical impedance measurements to follow the adsorption of giant liposomes on protein-coated solid surfaces with a time resolution in the order of seconds. The technical key features are circular gold-film electrodes as small as a few hundred micrometers in diameter and measurements of the electrode capacitance using AC signals in the kilohertz regime. Using Monte Carlo simulations, we were able to support the experiments and extract the rate constant of liposome adsorption. Besides monitoring the adsorption of liposomes on protein-coated surfaces, we also applied this technique to study shape fluctuations of the adsorbed vesicles and compared the corresponding power spectra with those recorded for hard particles and living animal cells. 相似文献
49.
Using direct laser writing, we fabricate photoresist templates for 3D-2D-3D photonic crystal heterostructures for what we believe to be the first time. The optical properties of these structures are directly compared with the theoretical ideal, revealing good agreement and hence good sample quality. This provides an experimental starting point for the microfabrication and testing of broadband, 3D air-waveguide microcircuitry in photonic bandgap materials. 相似文献
50.
For the modeling of turbulence effects on the dynamics of a long slender elastic fiber, a mathematical aerodynamic force concept is presented in this work. It yields a correlated random Gaussian force and respectively uncorrelated Gaussian white noise with flow-dependent amplitude in the asymptotic limit on the macroscopic fiber scale. Numerical comparisons of the correlated and uncorrelated force effects on the fiber behavior show coinciding results. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献