@article{ChristensenSchulteLadbeckSanchezetal.2005, author = {Christensen, Lise Bech and Schulte-Ladbeck, R. E. and Sanchez, Sebastian F. and Becker, Thomas and Jahnke, Knud and Kelz, A. and Roth, Martin M. and Wisotzki, Lutz}, title = {Abundances and kinematics of a candidate sub-damped Lymana galaxy toward PHL 1226}, year = {2005}, abstract = {The spectrum of the quasar PHL 1226 is known to have a strong Mg II and sub-damped Lymanalpha (sub-DLA) absorption line system with N(H I) = (5 +/- 2) x 10(19) cm(-2) at z = 0.1602. Using integral field spectra from the Potsdam Multi Aperture Spectrophotometer (PMAS) we investigate a galaxy at an impact parameter of 6".4 which is most probably responsible for the absorption lines. A fainter galaxy at a similar redshift and a slightly larger distance from the QSO is known to exist, but we assume that the absorption is caused by the more nearby galaxy. From optical Balmer lines we estimate an intrinsic reddening consistent with 0, and a moderate star formation rate of 0.5 M-circle dot yr(-1) is inferred from the Ha luminosity. Using nebular emission line ratios we find a solar oxygen abundance 12 + log (O/H) = 8.7 +/- 0.1 and a solar nitrogen to oxygen abundance ratio log (N/O) = -1.0 +/- 0.2. This abundance is larger than those of all known sub-DLA systems derived from analyses of metal absorption lines in quasar spectra. On the other hand, the properties are compatible with the most metal rich galaxies responsible for strong Mg II absorption systems. These two categories can be reconciled if we assume an abundance gradient similar to local galaxies. Under that assumption we predict abundances 12 + log (O/H) = 7.1 and log (N/O) = -1.9 for the sub-DLA cloud, which is similar to high redshift DLA and sub-DLA systems. We find evidence for a rotational velocity of similar to200 km s(-1) over a length of similar to7 kpc. From the geometry and kinematics of the galaxy we estimate that the absorbing cloud does not belong to a rotating disk, but could originate in a rotating halo}, language = {en} } @phdthesis{Brezesinski2005, author = {Brezesinski, Torsten}, title = {Herstellung und Charakterisierung funktioneller Mesostrukturierter Metalloxidfilme}, address = {Potsdam}, pages = {Getr. Z{\"a}hlung : Ill., graph. Darst.}, year = {2005}, language = {de} } @article{WittSchumann2005, author = {Witt, Annette and Schumann, A. Y.}, title = {Holocene climate variability on millennial scales recorded in Greenland ice cores}, issn = {1023-5809}, year = {2005}, language = {en} } @article{BragardMontbrioMendozaetal.2005, author = {Bragard, Jean and Montbrio, Ernest and Mendoza, C. and Boccaletti, Stefano and Blasius, Bernd}, title = {Defect-enhanced anomaly in frequency synchronization of asymmetrically coupled spatially extended systems}, year = {2005}, abstract = {We analytically establish and numerically show that anomalous frequency synchronization occurs in a pair of asymmetrically coupled chaotic space extended oscillators. The transition to anomalous behaviors is crucially dependent on asymmetries in the coupling configuration, while the presence of phase defects has the effect of enhancing the anomaly in frequency synchronization with respect to the case of merely time chaotic oscillators.}, language = {en} } @article{FussmannBlasius2005, author = {Fussmann, Gregor F. and Blasius, Bernd}, title = {Community response to enrichment is highly sensitive to model structure}, year = {2005}, abstract = {Biologists use mathematical functions to model, understand, and predict nature. For most biological processes, however, the exact analytical form is not known. This is also true for one of the most basic life processes, the uptake of food or resources. We show that the use of a number of nearly indistinguishable functions, which can serve as phenomenological descriptors of resource uptake, may lead to alarmingly different dynamical behaviour in a simple community model. More specifically, we demonstrate that the degree of resource enrichment needed to destabilize the community dynamics depends critically on the mathematical nature of the uptake function.}, language = {en} } @article{BlasiusToenjes2005, author = {Blasius, Bernd and Toenjes, Ralf}, title = {Quasiregular concentric waves in heterogeneous lattices of coupled oscillators}, year = {2005}, abstract = {We study the pattern formation in a lattice of locally coupled phase oscillators with quenched disorder. In the synchronized regime quasi regular concentric waves can arise which are induced by the disorder of the system. Maximal regularity is found at the edge of the synchronization regime. The emergence of the concentric waves is related to the symmetry breaking of the interaction function. An explanation of the numerically observed phenomena is given in a one- dimensional chain of coupled phase oscillators. Scaling properties, describing the target patterns are obtained.}, language = {en} } @article{HuppertBlasiusOlinkyetal.2005, author = {Huppert, Amit and Blasius, Bernd and Olinky, Ronen and Stone, Lewi}, title = {A Model for Seasonal Phytoplankton Blooms}, year = {2005}, abstract = {We analyse a generic bottom-up nutrient phytoplankton model to help understand the dynamics of seasonally recurring algae blooms. The deterministic model displays a wide spectrum of dynamical behaviours, from simple cyclical blooms which trigger annually, to irregular chaotic blooms in which both the time between outbreaks and their magnitudes are erratic. Unusually, despite the persistent seasonal forcing, it is extremely difficult to generate blooms that are both annually recurring and also chaotic or irregular (i.e. in amplitude) even though this characterizes many real time series. Instead the model has a tendency to `skip' with outbreaks often being suppressed from one year to the next. This behaviour is studied in detail and we develop an analytical expression to describe the model's flow in phase space, yielding insights into the mechanism of the bloom recurrence. We also discuss how modifications to the equations through the inclusion of appropriate functional forms can generate more realistic dynamics.}, language = {en} } @phdthesis{Herrmann2005, author = {Herrmann, Frank}, title = {Evolution and analysis of binary black hole spacetimes}, address = {Potsdam}, pages = {xv, 127 S. : graph. Darst.}, year = {2005}, language = {en} } @phdthesis{Mechau2005, author = {Mechau, Norman}, title = {Lichtinduziertes Erweichen azobenzolhaltiger Polymerfilme}, address = {Potsdam}, pages = {156 S. : graph. Darst.}, year = {2005}, language = {de} } @phdthesis{Saha2005, author = {Saha, Subodh Kumar}, title = {The influence of an improved soil scheme on the arctic climate in a RCM}, address = {Potsdam}, pages = {x, 115 S. : graph. Darst.}, year = {2005}, language = {en} } @article{HayerKhanFriendetal.2005, author = {Hayer, Anna and Khan, A. L. T. and Friend, Richard H. and K{\"o}hler, Anna}, title = {Morphology dependence of the triplet excited state formation and absorption in polyfluorene}, year = {2005}, language = {en} } @phdthesis{Leisner2005, author = {Leisner, Antje}, title = {Entwicklung von Modellkompetenz im Physikunterricht}, series = {Studien zum Physik- und Chemielernen}, volume = {44}, journal = {Studien zum Physik- und Chemielernen}, publisher = {Logos-Verl.}, address = {Berlin}, isbn = {3-8325-1020-6}, issn = {1614-8967}, pages = {vii, 264, XLII S. : Ill., graph. Darst.}, year = {2005}, language = {de} } @article{WichmannJohstSchwageretal.2005, author = {Wichmann, Matthias and Johst, Karin and Schwager, Monika and Jeltsch, Florian and Blasius, Bernd}, title = {Extinction risk, coloured noise and the scaling of variance}, year = {2005}, abstract = {The impact of temporally correlated fluctuating environments (coloured noise) on the extinction risk of populations has become a main focus in theoretical population ecology. In this study we particularly focus on the extinction risk in strongly autocorrelated environments. Here, in contrast to moderate autocorrelation, we found the extinction risk to be highly dependent on the process of noise generation, in particular on the method of variance scaling. Such variance scaling is commonly applied to avoid variance-driven biases when comparing the extinction risk for white and coloured noise. In this study we found an often-used scaling technique to lead to high variability in the resulting variances of different time series for strong auto-correlation eventually leading to deviations in the projected extinction risk. Therefore, we present an alternative method that always delivers the target variance, even in the case of strong temporal correlation. Furthermore, in contrast to the earlier method, our very intuitive method is not bound to auto-regressive processes but can be applied to all types of coloured noises. We recommend the method introduced here to be used when the target of interest is the effect of noise colour on extinction risk not obscured by any variance effects.}, language = {en} } @phdthesis{Dittrich2005, author = {Dittrich, Bianca}, title = {Aspects of classical and quantum dynamics of canonical general relativity}, address = {Potsdam}, pages = {173 S.}, year = {2005}, language = {en} } @phdthesis{Mishra2005, author = {Mishra, Narayan Chandra}, title = {Interactions in and stability of thin liquid films}, address = {Potsdam}, pages = {x, 110 S. : graph. Darst.}, year = {2005}, language = {en} } @phdthesis{Aulbert2005, author = {Aulbert, Carsten}, title = {Finding millisecond binary pulsars in 47 tucanae by applying the hough transformation to radio data}, address = {Potsdam}, pages = {173 S. : graph. Darst.}, year = {2005}, language = {en} } @article{LiMoehwaldSpitzetal.2005, author = {Li, L. and M{\"o}hwald, Helmuth and Spitz, Christian and von Seggern, David and Mucke, M. and Menzel, Ralf}, title = {Long-lived photoinduced charge separation inside polarity gradient capsules}, year = {2005}, language = {en} } @phdthesis{DiezSanJose2005, author = {Diez San Jose, Isabel Maria}, title = {Shaping of conductive polypyrrole during polymerization}, address = {Potsdam}, pages = {100 Bl. : Ill., graph. Darst.}, year = {2005}, language = {en} } @phdthesis{Schwarzer2005, author = {Schwarzer, Rolf}, title = {Identification of REDDI and TRB3 as novel transcriptional targets of PI 3-kinase signalling and analysis of their involvement in growth of cancer cells}, address = {Potsdam}, pages = {99 S. : graph. Darst.}, year = {2005}, language = {en} } @article{BrilliantovPoschel2005, author = {Brilliantov, Nikolai V. and Poschel, T.}, title = {Self-diffusion in granular gases : Green-Kubo versus Chapman-Enskog}, issn = {1054-1500}, year = {2005}, abstract = {We study the diffusion of tracers (self-diffusion) in a homogeneously cooling gas of dissipative particles, using the Green-Kubo relation and the Chapman-Enskog approach. The dissipative particle collisions are described by the coefficient of restitution epsilon which for realistic material properties depends on the impact velocity. First, we consider self-diffusion using a constant coefficient of restitution, epsilon=const, as frequently used to simplify the analysis. Second, self-diffusion is studied for a simplified (stepwise) dependence of epsilon on the impact velocity. Finally, diffusion is considered for gases of realistic viscoelastic particles. We find that for epsilon=const both methods lead to the same result for the self-diffusion coefficient. For the case of impact-velocity dependent coefficients of restitution, the Green-Kubo method is, however, either restrictive or too complicated for practical application, therefore we compute the diffusion coefficient using the Chapman-Enskog method. We conclude that in application to granular gases, the Chapman-Enskog approach is preferable for deriving kinetic coefficients. (C) 2005 American Institute of Physics}, language = {en} }