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61.
We study the energy flow due to the motion of topological solitons in nonlinear extended systems in the presence of damping and driving. The total field momentum contribution to the energy flux, which reduces the soliton motion to that of a point particle, is insufficient. We identify an additional exchange energy flux channel mediated by the spatial and temporal inhomogeneity of the system state. In the well-known case of a dc external force the corresponding exchange current is shown to be small but nonzero. For the case of ac driving forces, which lead to a soliton ratchet, the exchange energy flux mediates the complete energy flow of the system. We also consider the case of combination of ac and dc external forces, as well as spatial discretization effects. 相似文献
62.
Nonlinear classical Hamiltonian lattices exhibit generic solutions — discrete breathers. They are time-periodic and (typically exponentially) localized in space. The lattices have discrete translational symmetry. Discrete breathers are not confined to certain lattice dimensions. We will introduce the concept of these localized excitations and review their basic properties including dynamical and structural stability. We then focus on advances in the theory of discrete breathers in three directions — scattering of waves by these excitations, persistence of discrete breathers in long transient processes and thermal equilibrium, and their quantization. The second part of this review is devoted to a detailed discussion of recent experimental observations and studies of discrete breathers, including theoretical modelling of these experimental situations on the basis of the general theory of discrete breathers. In particular we will focus on their detection in Josephson junction networks, arrays of coupled nonlinear optical waveguides, Bose–Einstein condensates loaded on optical lattices, antiferromagnetic layered structures, PtCl based single crystals and driven micromechanical cantilever arrays. 相似文献
63.
64.
Jutta Rado und S. Gorbach 《Fresenius' Journal of Analytical Chemistry》1980,302(1):15-19
Zusammenfassung Geräte und Prinzip einer miniaturisierten Arbeitsweise in der Rückstandsanalytik werden beschrieben. Die praktische Anwendung wird am Beispiel der Rückstandsbestimmung von Pyrazophos und Triazophos demonstriert. Diese Mikrotechnik erfordert weniger Zeit, weniger Material (von Bedeutung bei gefährlichen Lösungsmitteln) und eine kleinere Arbeitsfläche als die übliche Makroarbeitsweise.
Application of microchemical methods in residue analysisPractical experiences
Summary Equipment and principle of a miniaturized mode of working in residue analysis are described and are demonstrated with the example of the residue determination of pyrazophos and triazophos. This micro-technique offers the advantage of requiring less time, less material (in particular of importance for hazardous solvents) and a smaller working area than the usual macro-method.
Herrn Prof. Dr. R. Bock zum 65. Geburtstag in Dankbarkeit gewidmet 相似文献
65.
F. Ehrenberger S. Gorbach und K. Hommel 《Fresenius' Journal of Analytical Chemistry》1965,210(5):349-354
Zusammenfassung Die elementaranalytische Bestimmung von Chlor, Brom, Jod, Fluor und Schwefel sowie die Spurenbestimmung dieser Elemente in organischen Substanzen wurde durch wesentliche Vereinfachung des Substanzaufschlusses in einer modifizierten Wickbold-Apparatur (Knallgasverbrennung) bedeutend verbessert und beschleunigt.
Alleinhersteller: Fa. Heraeus, Quarzschmelze GmbH., Hanau/Main, Rohrstr.8. 相似文献
Summary The determination of chlorine, bromine, iodine, fluorine and sulphur including the determination of traces of these elements in organic substances is significantly improved by a modified Wickbold apparatus. The modification permits to introduce a new sample and to rinse the absorber after a finished combustion without turning-off the oxygen-hydrogen flame.
Alleinhersteller: Fa. Heraeus, Quarzschmelze GmbH., Hanau/Main, Rohrstr.8. 相似文献
66.
Using an example of a Raman active medium we describe how a common nonlinear process of four-wave mixing can be used to induce strong coupling between the spatial and temporal degrees of freedom in optical waves. This coupling produces several unexpected effects. Amongst those are cascaded excitation of multiply charged optical vortices, spatial focusing in a nonlinearly defocusing medium, and generation of helically shaped spatiotemporal optical solitons. 相似文献
67.
D. V. Gorbach S. A. Nazarov A. L. Tolstik 《Bulletin of the Russian Academy of Sciences: Physics》2013,77(12):1412-1415
The characteristics of diffracted waves derived from four- and six-wave mixing in a solution of Rhodamine 6G dye are studied in different combinations ofthe polarization states of waves that participate in wave interaction. 相似文献
68.
Ding W Staines OK Hobbs GD Gorbach AV de Nobriga C Wadsworth WJ Knight JC Skryabin DV Strain MJ Sorel M De La Rue RM 《Optics letters》2012,37(4):668-670
We report frequency conversion experiments in silicon-on-insulator (SOI) directional couplers. We demonstrate that the evanescent coupling between two subwavelength SOI waveguides is strongly dispersive and significantly modifies modulational instability (MI) spectra through the coupling induced group velocity dispersion (GVD). As the separation between two 380-nm-wide silicon photonic wires decreases, the increasing dispersion of the coupling makes the GVD in the symmetric supermode more normal and suppresses the bandwidth of the MI gain observed for larger separations. 相似文献
69.
Resonant ultrasound spectroscopy was used to measure the elastic constants of bcc Ta0.33V0.67 over the temperature range 3.5–300?K; the results were compared to earlier measurements on C15 TaV2. The temperature dependence of the polycrystalline shear modulus is completely different in the two phases; that of the bcc phase decreases with temperature whereas that of the C15 phases increases in an anomalous fashion. This difference is consistent with a model involving doubly-degenerate levels at the X point of the Brillouin zone in the C15 phase with the Fermi level lying near the doubly degenerate level. This model accounted for the unusual behaviour of the C15 phase. Debye temperatures were determined from the ultrasonic measurements: 295?K for the C15 phase and 315?K for the bcc phase. 相似文献
70.
G. A. Naberezhnykh V. I. Gorbach S. Yu. Bratskaya T. F. Soloveva 《Chemistry of Natural Compounds》2011,46(6):852-856
Amphiphilic low-molecular-weight chitosan N-acylated with 3-hydroxytetradecanoic acid was synthesized. It was shown that addition of the acylated chitosan changes the
surface potential and size of negatively charged liposomal particles, the magnitudes of which depend on the chitosan concentration.
Charge neutralization and aggregation of the liposomes occurs at low chitosan concentration. Increasing its concentration
produces positive charge on the surface of the liposomes and decreases their size. This increases the stability of the liposomal
particles in solution. Liposomes coated with chitosan may be of interest as carriers for genes, vaccines, and drugs. 相似文献