TY - THES A1 - Regenstein, Wolfgang T1 - Absorptionsspektroskopische Untersuchungen zum Einfluß des Mediums und des Aggregatzustandes auf die Gestalt und Lage der Charge-Transfer-Bande N2 - An einigen CT-Modellkomplexen in verschiedenen Lösungsmitteln und bei Temperaturen von 113-300 K sollte der Einfluß der Umgebung auf die Form und Lage der Absorption von CT-Komplexen unterschiedlicher Bindungsfestigkeit untersucht werden. Dazu wurden bekannte Bandenprofilfunktionen auf ihre Anwendbar-keit geprüft. Da eine optimale Anpassung nicht möglich war, wurde eine neue Profilfunktion entwickelt, die eine bessere Beschreibung ergab. Nach der Bestimmung der Gleichgewichtskonstante und des Extink-tionskoeffizienten konnte mit der Profilfläche das Übergangsmoment berechnet werden. Die Lösungsmittelabhängigkeit wurde bei verschiedenen Brechzahlen und Dielektrizitätskonstanten untersucht. Für feste Komplexe wurde eine spezielle Präparationstechnik gewählt. Die beobachteten Feinstrukturen und der auftretende Streuuntergrund werden diskutiert. N2 - At some CT model complexes in various solvents and temperatures between 113- 300 K should investigate the influence of envirenment on the shape and position of CT complexes at various binding forces. Thereto known band profile functions were checked for their applicability. Because it was impossible to get an optimal accomodation a new profile function was developed, that results in a better description. After determination of equilibrium constant and extinction coefficient it was possible to calculate the transition moment with profiled area. The solvent dependence was investigated with various refractive indexes and dielectric constants. For solid complexes were selected a special preparation technique. The observed fine structures and the appered scattering underground were discussed. T2 - Absorption spectroscopic investigations on the influence of medium and aggregate state on the shape and position of CT bands KW - CT Komplex KW - Bandenprofil KW - Übergangsmoment KW - Lösungsmittelabhängigkeit KW - Präparation fester Komplexe KW - CT complex KW - band profile KW - transition moment KW - solvent dependence KW - solid complex preparation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-496702 ER - TY - THES A1 - Regenstein, Wolfgang T1 - Fluoreszenzlöschung durch Elektronen- und Resonanzenergietransfer in Lösungen T1 - Fluorescence quenching through electron and resonant energy transfer in solutions N2 - Intermolekulare Desaktivierung zwischen einem angeregten Fluorophor und einem Löscher durch Elektronenübertragung kann mit dynamischer und statischer Löschung beschrieben werden. Es wird vorgeschlagen den dynamischen Löschprozess in Transport- und Wechselwirkungsphase einzuteilen. Ergebnisse der Löschung der N-Heteroarene durch Naphthalen bei hohen Löscherkonzentrationen werden mit der statischen Löschung beschrieben. Außerdem werden CT-Systeme untersucht. Nach einem Überblick über statische Modelle zum Resonanzenergietransfer wird ein aus der Treffertheorie abgeleitetes Modell vorgestellt und an Beispielen getestet. Die Experimente sind computergesteuert. N2 - The intermolecular deactivation through dynamic and static quenching can described with electron transition between an excited fluorophor and quencher. It is proposed to devide the dynamic quenching process in a transport and an interaction phase. Results oft the quenching of N-heteroarenes through naphthalenes by high concentrations are described with static quenching. CT-systems are also investigated. After giving an overview of statistical models of resonant energy transfer there is presented a model derived from the hit theory. The models were tested by examples. The experiments were executed computer-controlled. KW - Intermolekulare Desaktivierung KW - dynamische und statische Löschung KW - Transport- und Wechselwirkungsphase KW - Resonanzenergietransfer KW - statistische Modelle KW - Intermolecular deactivation KW - dynamic and static quenching KW - transport and interaction phase KW - resonant energy transfer KW - statistical models Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-491377 N1 - Überarbeitete Fassung der Habilitationsschrift aus dem Jahr 1989 ER - TY - JOUR A1 - Neumann, Werner A1 - Kasper, Sabine A1 - Kasper, Roberto T1 - Discharge Currents in Polymer Solids between Blocking Contacts Y1 - 1991 SN - 0-7803-0113- 7 ER - TY - JOUR A1 - Neumann, Werner T1 - Stromträgerrelaxationen in hochohmigen Polymerfestkörpern Y1 - 1991 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Dietel, Reinhard A1 - Lemmetyinen, Helge A1 - Janietz, Dietmar A1 - Lemmetyinen, Helge A1 - Brehmer, Ludwig T1 - Edge-on Langmuir-Blodgett multilayers derived from disc-shaped multiyne mesogens N2 - Langmuir-Blodgett(LB) multilayers were prepared from disc-shaped multiyne mesogens based on amphiphilic alkyl pentakis(aryl-ethynyl)benzene ethers. The two compounds used are characterized by five hydrophobic flexible chains and one hydrophilic substituent at the terminal position of the alkoxy chain. The LB films were analysed by X-ray scattering and spectroscopic measurements. An edge-on arrangement of the two discotic pentaalkynes within Y-type bilayers with a different packing density proved to be possible for the LB films of both compounds. Y1 - 1992 ER - TY - THES A1 - Sprengel, Jens-Uwe T1 - Analyse der Transfermatrizen geschichteter anisotroper Medien Y1 - 1992 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Pietsch, Ullrich A1 - Fink, Hans-Peter A1 - Lemmetyinen, Helge T1 - A comparison fo x-ray methods for structure refinement of Langmuir-Blodgett multilayers N2 - The possibilities and limits of structure refinement of Langmuir-Blodgett films by means of symmetrical reflection of X- rays are described using the example of a stearic acid multilayer. Three different techniques for the determiantion of the electron density profile from reflectivity data are compared; a Fourier method, a Patterson method, and model calculations. The important role of the a priori information for finding the besft structure model is outlined. Y1 - 1992 ER - TY - JOUR A1 - Mikelskis, Helmut T1 - Combining issues of "girl-suited" science teaching, STS and constructivism in a physics textbook Y1 - 1992 SN - 0157-244X ER - TY - JOUR A1 - Mikelskis, Helmut T1 - Physiklernen heißt: Brücken schlagen zwischen toten Zahlen und sinnlichem Dasein Y1 - 1992 SN - 3-89088-061-4 ER - TY - JOUR A1 - Mikelskis, Helmut T1 - Wo bleibt das Phänomen im Experiment? Y1 - 1992 SN - 3-88064-212-5 ER - TY - THES A1 - Wedel, Armin T1 - Untersuchungen zum Dipolschaltverhalten an Polymerfestkörpern Y1 - 1992 ER - TY - THES A1 - Gerhard, Reimund T1 - Präparation und Untersuchung von Festkörperschichten für Sensorik und Photonik : eine Zusammenstellung von Veröffentlichungen Y1 - 1992 ER - TY - JOUR A1 - Mikelskis, Helmut T1 - Schneller als der Wind : zur Behandlung des Darrieus-Windrotors im Physikunterricht Y1 - 1993 ER - TY - JOUR A1 - Mikelskis, Helmut T1 - Zukunftsperspektiven physikdidaktischer Forschung im vereinigten Deutschland Y1 - 1993 SN - 3-88064-223-0 ER - TY - BOOK A1 - Duit, Reinders A1 - Mikelskis, Helmut T1 - Physik, um die Welt zu begreifen : ein Lehrbuch für die Jahrgangsstufe 5/6 ; [Hauptbd.], Nordrhein- Westfalen Y1 - 1993 SN - 3-425-03671-8 PB - Diesterweg CY - Frankfurt am Main ER - TY - BOOK A1 - Duit, Reinders A1 - Mikelskis, Helmut T1 - Physik - Chemie, um die Welt zu begreifen : ein Lehrbuch für die Orientierungsstufe ; [Hauptbd.], Niedersachsen Y1 - 1993 SN - 3-425-03675-0 VL - 3675 PB - Diesterweg CY - Frankfurt am Main ER - TY - JOUR A1 - Mikelskis, Helmut T1 - Zur Ökologisierung des Lernprozesses : Versuch über einen vernachlässigten Aspekt von Umweltbildung Y1 - 1993 SN - 3-89088-073-8 ER - TY - BOOK A1 - Marquardt-Mau, Brunhilde A1 - Mayer, Jürgen A1 - Mikelskis, Helmut T1 - Umwelt : Lexikon ökologisches Grundwissen Y1 - 1993 SN - 3-499-16337-3 VL - 6337 PB - Rowohlt CY - Reinbek bei Hamburg ER - TY - BOOK A1 - Hänsel, Horst A1 - Neumann, Werner A1 - Hudel, Erich T1 - Physik : Bd. 2 Elektrizität, Optik, Raum und Zeit Y1 - 1993 SN - 3-86025-304-2 VL - 2 PB - Spektrum Akad. Verl. CY - Heidelberg ER - TY - THES A1 - Pedzisz, Bozena T1 - Zur Rolle historischer Betrachtungen im Physikunterricht unter besonderer Berücksichtigung grundlegender Experimente Y1 - 1993 ER - TY - BOOK A1 - Hänsel, Horst A1 - Neumann, Werner A1 - Wedell, Reiner T1 - Physik : Bd. 1 Mechanik und Wärmelehre Y1 - 1993 SN - 3-86025-046-9 VL - 1 PB - Spektrum Akad. Verl. CY - Heidelberg ER - TY - JOUR A1 - Hubrig, Swetlana A1 - Mathys, Gautier T1 - Mass loss, magnetic field and chemical inhomogenities in the he-weak star HD 21699 Y1 - 1993 ER - TY - INPR A1 - Witt, Annette A1 - Kurths, Jürgen A1 - Krause, F. A1 - Fischer, K. T1 - On the validity of a model for the reversals of the Earth‘s magnetic field N2 - We have used techniques of nonlinear dynamics to compare a special model for the reversals of the Earth's magnetic field with the observational data. Although this model is rather simple, there is no essential difference to the data by means of well-known characteristics, such as correlation function and probability distribution. Applying methods of symbolic dynamics we have found that the considered model is not able to describe the dynamical properties of the observed process. These significant differences are expressed by algorithmic complexity and Renyi information. T3 - NLD Preprints - 4 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13460 ER - TY - INPR A1 - Kurths, Jürgen A1 - Voss, A. A1 - Witt, Annette A1 - Saparin, P. A1 - Kleiner, H. J. A1 - Wessel, Niels T1 - Quantitative analysis of heart rate variability N2 - In the modern industrialized countries every year several hundred thousands of people die due to the sudden cardiac death. The individual risk for this sudden cardiac death cannot be defined precisely by common available, non-invasive diagnostic tools like Holter-monitoring, highly amplified ECG and traditional linear analysis of heart rate variability (HRV). Therefore, we apply some rather unconventional methods of nonlinear dynamics to analyse the HRV. Especially, some complexity measures that are basing on symbolic dynamics as well as a new measure, the renormalized entropy, detect some abnormalities in the HRV of several patients who have been classified in the low risk group by traditional methods. A combination of these complexity measures with the parameters in the frequency domain seems to be a promising way to get a more precise definition of the individual risk. These findings have to be validated by a representative number of patients. T3 - NLD Preprints - 5 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13470 ER - TY - JOUR A1 - Seehafer, Norbert T1 - Relaxation to equilibrium and inverse energy cascades in solar active regions Y1 - 1994 SN - 1-563-47099-3 SN - 0079-6050 ER - TY - JOUR A1 - Seehafer, Norbert T1 - Current helicity and the turbulent electromotive force Y1 - 1994 ER - TY - JOUR A1 - Seehafer, Norbert T1 - Alpha effect in the solar atmosphere Y1 - 1994 ER - TY - INPR A1 - Feudel, Fred A1 - Seehafer, Norbert T1 - On the bifurcation phenomena in truncations of the 2D Navier-Stokes equations N2 - We have studied bifurcation phenomena for the incompressable Navier-Stokes equations in two space dimensions with periodic boundary conditions. Fourier representations of velocity and pressure have been used to transform the original partial differential equations into systems of ordinary differential equations (ODE), to which then numerical methods for the qualitative analysis of systems of ODE have been applied, supplemented by the simulative calculation of solutions for selected initial conditions. Invariant sets, notably steady states, have been traced for varying Reynolds number or strength of the imposed forcing, respectively. A complete bifurcation sequence leading to chaos is described in detail, including the calculation of the Lyapunov exponents that characterize the resulting chaotic branch in the bifurcation diagram. T3 - NLD Preprints - 1 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13390 ER - TY - GEN A1 - Henkel, Carsten A1 - Steane, Andrew M. A1 - Kaiser, Robin A1 - Dalibard, Jean T1 - A modulated mirror for atomic interferometry N2 - A novel atomic beam splitter, using reflection of atoms off an evanescent light wave, is investigated theoretically. The intensity or frequency of the light is modulated in order to create sidebands on the reflected de Broglie wave. The weights and phases of the various sidevands are calculated using three different approaches: the Born approximation, a semiclassical path integral approach, and a numerical solution of the time-dependent Schrdinger equation. We show how this modulated mirror could be used to build practical atomic interferometers. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 102 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42279 ER - TY - GEN A1 - Henkel, Carsten A1 - Courtois, Jean-Yves A1 - Aspect, Alain T1 - Atomic diffraction by a thin phase grating N2 - We present a semiclassical perturbation method for the description of atomic diffraction by a weakly modulated potential. It proceeds in a way similar to the treatment of light diffraction by a thin phase grating, and consists in calculating the atomic wavefunction by means of action integrals along the classical trajectories of the atoms in the absence of the modulated part of the potential. The capabilities and the validity condition of the method are illustrated on the well-known case of atomic diffraction by a Gaussian standing wave. We prove that in this situation the perturbation method is equivalent to the Raman-Nath approximation, and we point out that the usually-considered Raman-Nath validity condition can lead to inaccuracies in the evaluation of the phases of the diffraction amplitudes. The method is also applied to the case of an evanescent wave reflection grating, and an analytical expression for the diffraction pattern at any incidence angle is obtained for the first time. Finally, the application of the method to other situations is briefly discussed. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 101 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42269 ER - TY - GEN A1 - Henkel, Carsten A1 - Courtois, Jean-Yves A1 - Kaiser, Robin A1 - Westbrook, C. A1 - Aspect, Alain T1 - Phase shifts of atomic de Broglie waves at an evanescent wave mirror N2 - A detailed theoretical investigation of the reflection of an atomic de Broglie wave at an evanescent wave mirror is presented. The classical and the semiclassical descriptions of the reflection process are reviewed, and a full wave-mechanical approach based on the analytical soution of the corresponding Schrödinger equation is presented. The phase shift at reflection is calculated exactly and interpreted in terms of instantaneous reflection of the atom at an effective mirror. Besides the semiclassical regime of reflection describable by the WKB method, a pure quantum regime of reflection is identified in the limit where the incident de Broglie wavelength is large compared to the evanescent wave decay length. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 103 Y1 - 1994 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-42289 ER - TY - JOUR A1 - Janietz, Dietmar A1 - Hofmann, Dieter A1 - Reiche, Jürgen T1 - Molecular organization of amphiphilic disc-shaped penta-alkynes in LB-mono- and multilayers N2 - Amphiphilic disc-shaped penta-alkynes were studied with regard to their molecular organization in Langmuir-Blod- gett (LB) mono- and multilayers. It was found that each compound investigated forms edge-on arranged stable monolayers at the air-water interface. LB-multilayers derived from fivefold pentyl-substituted pentaynes are characterized by an edge-on ordering of the molecules within Y-type bilayers. One of these compounds, containing a hydoxy substituent as hydrophilic head group, is exemplified and two possible rectangular molecular assemblies perpendicular to the substrate, each with a columnar in-plane packing, will be discussed as a result of molecular modelling. Based on the experimental results, hexagonal layer packing in the LB-film of a disc-shaped penta-alkynyl carboxylic acid without lateral substituents proved to be possible, which, furthermore, could be confirmed by molecular mechanics simulation. Y1 - 1994 ER - TY - JOUR A1 - Hochheimer, H. D. A1 - Menon, V. A1 - Parthasarathy, R. A1 - Martin, C. R. A1 - Bechthold, Jeff A1 - Hor, P.-H. A1 - Lorenz, Bernd A1 - Spatz, J. P. T1 - High pressure study of the temperature dependence of the conductivity of template synthesized polyaniline and polypyrrole Y1 - 1994 ER - TY - JOUR A1 - Hochheimer, H. D. A1 - Menon, V. A1 - Parthasarathy, R. A1 - Martin, C. R. A1 - Bechthold, Jeff A1 - Hor, P.-H. A1 - Lorenz, Bernd A1 - Spatz, J. P. T1 - High pressure conductivity of template synthesized polypyrrole Y1 - 1994 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Knochenhauer, Gerald T1 - Numerische Simulation und Röntgenbeugung an thermisch aufgedampften Multischichten perfluorierter Fettsäuren Y1 - 1994 ER - TY - JOUR A1 - Lorenz, Bernd A1 - Spatz, J. P. A1 - Hochheimer, H. D. A1 - Menon, V. A1 - Parthasarathy, R. A1 - Martin, C. R. A1 - Bechthold, Jeff A1 - Hor, P.-H. T1 - Dimensional crossover of the temperature dependence of the electrical conductivity of template synthesized polyaniline and polypyrrole Y1 - 1994 ER - TY - JOUR A1 - Lorenz, Bernd A1 - Tozer, S. W. A1 - Hochheimer, H. D. A1 - Menon, V. A1 - Parthasarathy, R. A1 - Martin, C. R. T1 - Magnetoresistance of conducting polymers Y1 - 1994 ER - TY - JOUR A1 - Lorenz, Bernd A1 - Spatz, J. P. A1 - Weishaupt, K. A1 - Hochheimer, H. D. A1 - Menon, V. A1 - Parthasarathy, R. A1 - Martin, C. R. A1 - Bechthold, Jeff A1 - Hor, P.-H. T1 - Observation of crossover from three to two dimensional variable range hopping in template synthesized polypyrrole and polyaniline Y1 - 1994 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Barberka, Thomas Andreas A1 - Knochenhauer, Gerald A1 - Woolley, Martin A1 - Pietsch, Ullrich T1 - Comprehensive structure investigation and computer modelling of perfluorododecanoic acid multilayers formed by in-vacuo thermal evaporation Y1 - 1994 ER - TY - JOUR A1 - Werner, Klaus A1 - Barstow, Martin A. A1 - Holberg, J. B. A1 - Koester, D. A1 - Nousek, J. A. T1 - Extreme ultraviolet spectroscopy of white dwarfs Y1 - 1994 ER - TY - JOUR A1 - Reiche, Jürgen A1 - Barberka, Thomas Andreas A1 - Janietz, Dietmar A1 - Hofmann, Dieter A1 - Pietsch, Ullrich A1 - Brehmer, Ludwig T1 - X-ray structure investigation and computer modelling of Langmuir-Blodgett films formed from disc-shaped pentaalkines Y1 - 1994 ER - TY - JOUR A1 - Liperovskaya, E. V. A1 - Pochotelov, O. A. A1 - Liperovsky, Viktor A. A1 - Oleynik, M. A. A1 - Meister, Claudia-Veronika A1 - Christakis, N. T1 - A comparison of seismic and anthropogenic effects in the night-time sporadic E-layer of the ionosphere Y1 - 1994 ER - TY - JOUR A1 - Baier, Frank W. A1 - McGillivray, H. T. A1 - Flin, P. A1 - Krywult, J. T1 - The imadmissibility of radial number density profiles of galaxy clusters Y1 - 1994 ER - TY - JOUR A1 - Angelova, Angelina A1 - Penacorada, Florencio A1 - Stiller, Burkhard A1 - Zetzsche, Thomas A1 - Ionov, Radoslav A1 - Kamusewitz, Helmut A1 - Brehmer, Ludwig T1 - Wettability, surface morphology and stability of long chain ester multilayers obtained by different Langmuir- Blodgett deposition type Y1 - 1994 ER - TY - JOUR A1 - Janietz, Dietmar A1 - Festag, R. A1 - Schmidt, C. A1 - Wendorff, Joachim Heinz T1 - Self-organization of new oligomers containing disc-shaped side groups Y1 - 1994 ER - TY - JOUR A1 - Schulz, Burkhard A1 - Stiller, Burkhard A1 - Zetzsche, Thomas A1 - Knochenhauer, Gerald A1 - Dietel, Reinhard A1 - Brehmer, Ludwig T1 - Crystal structure of 2,5-Di(4- methoxycarbonyl-phenyl)-1,3,4-oxadiazole characterized by AFM and IR- spectroscopy Y1 - 1994 ER - TY - JOUR A1 - Lorenz, Bernd A1 - Miller, A. J. A1 - Hochheimer, H. D. A1 - Hönle, W. T1 - The observation of a new high pressure phase transition in tetramethyl ammonium tetrabromocuprate Y1 - 1994 ER - TY - JOUR A1 - Mercer, Frank W. A1 - McKenzie, M. A1 - Bruma, Maria A1 - Schulz, Burkhard T1 - Synthesis and properties of fluorinated polyimides and fluorinated poly(imide-amide)s containing pendent cyano groups Y1 - 1994 ER - TY - JOUR A1 - Liperovsky, Viktor A. A1 - Meister, Claudia-Veronika A1 - Haldoupis, Ch. A1 - Schlegel, K. T1 - Electrical currents and Farley-Buneman turbulence in mid-latitude sporadic E-layers Y1 - 1994 ER - TY - JOUR A1 - Sobisch, Titus A1 - Kühnemund, Lutz A1 - Hübner, Heike A1 - Reinisch, Gerhard A1 - Krägel, Jürgen T1 - Physicochemical aspects of in situ surfactant washing of oil contaminated soils Y1 - 1994 ER -