TY - JOUR A1 - Zimmermann, Malte T1 - Contrastive focus N2 - The article puts forward a discourse-pragmatic approach to the notoriously evasive phenomena of contrastivity and emphasis. It is argued that occurrences of focus that are treated in terms of ‘contrastive focus’, ‘kontrast’ (Vallduví & Vilkuna 1998) or ‘identificational focus’ (É. Kiss 1998) in the literature should not be analyzed in familiar semantic terms like introduction of alternatives or exhaustivity. Rather, an adequate analysis must take into account discourse-pragmatic notions like hearer expectation or discourse expectability of the focused content in a given discourse situation. The less expected a given content is judged to be for the hearer, relative to the Common Ground, the more likely a speaker is to mark this content by means of special grammatical devices, giving rise to emphasis. KW - contrastive focus KW - emphasis KW - discourse expectability Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-19688 ER - TY - JOUR A1 - Zimmermann, Alexander A1 - Wilcke, Wolfgang A1 - Elsenbeer, Helmut T1 - Spatial and temporal patterns of throughfall quantity and quality in a tropical montane forest in Ecuador Y1 - 2007 UR - http://www.sciencedirect.com/science/article/pii/S0022169407003460 U6 - https://doi.org/10.1016/j.jhydrol.2007.06.012 SN - 0022-1694 ER - TY - JOUR A1 - Zhang, Bo A1 - Henkel, Carsten T1 - Magnetic noise around metallic microstructures N2 - We compute the local spectrum of the magnetic field near a metallic microstructure at finite temperature. Our main focus is on deviations from a plane-layered geometry for which we review the main properties. Arbitrary geometries are handled with the help of numerical calculations based on surface integral equations. The magnetic noise shows a significant polarization anisotropy above flat wires with finite lateral width, in stark contrast to an infinitely wide wire. Within the limits of a two-dimensional setting, our results provide accurate estimates for loss and dephasing rates in so-called `atom chip traps' based on metallic wires. A simple approximation based on the incoherent summation of local current elements gives qualitative agreement with the numerics, but fails to describe current correlations among neighboring objects. Y1 - 2007 UR - http://dx.doi.org/10.1063/1.2800174 U6 - https://doi.org/10.1063/1.2800174 SN - 0021-8979 ER - TY - JOUR A1 - Zehe, Erwin A1 - Elsenbeer, Helmut A1 - Lindenmaier, Falk A1 - Schulz, K. A1 - Blöschl, Günter T1 - Patterns of predictability in hydrological threshold systems N2 - [1] Observations of hydrological response often exhibit considerable scatter that is difficult to interpret. In this paper, we examine runoff production of 53 sprinkling experiments on the water-repellent soils in the southern Alps of Switzerland; simulated plot scale tracer transport in the macroporous soils at the Weiherbach site, Germany; and runoff generation data from the 2.3-km(2) Tannhausen catchment, Germany, that has cracking soils. The response at the three sites is highly dependent on the initial soil moisture state as a result of the threshold dynamics of the systems. A simple statistical model of threshold behavior is proposed to help interpret the scatter in the observations. Specifically, the model portrays how the inherent macrostate uncertainty of initial soil moisture translates into the scatter of the observed system response. The statistical model is then used to explore the asymptotic pattern of predictability when increasing the number of observations, which is normally not possible in a field study. Although the physical and chemical mechanisms of the processes at the three sites are different, the predictability patterns are remarkably similar. Predictability is smallest when the system state is close to the threshold and increases as the system state moves away from it. There is inherent uncertainty in the response data that is not measurement error but is related to the observability of the initial conditions. Y1 - 2007 U6 - https://doi.org/10.1029/2006wr005589 SN - 0043-1397 ER - TY - JOUR A1 - Yoneda, Julliane Diniz A1 - Leal, Katia Zaccur A1 - Seidl, Peter Rudolf A1 - Azeredo, Rodrigo Bagueira de V. A1 - Kleinpeter, Erich T1 - Camphor : a good model for illustrating NMR techniques N2 - CAMPHOR: A GOOD MODEL FOR ILLUSTRATING NMR TECHNIQUES. The use of Nuclear Magnetic Resonance spectroscopy to establish the three-dimensional structures of molecules is an important component of modern Chemistry courses. The combination of techniques that can be used for this purpose is conveniently illustrated by their application to the camphor molecule. This paper presents applications of several techniques used in NMR spectral interpretation in an increasing order of complexity. The result of individual experiments is illustrated in order to familiarize the user with the way connectivity through bonds and through space is established from 1D/2D-NMR spectra and molecular stereochemistry is determined from different NMR experiments Y1 - 2007 ER - TY - JOUR A1 - Wischer, Ilse T1 - The Grammaticalization of the Perfect in the History of English Y1 - 2007 SN - 978-83-7525-071-8 ER - TY - JOUR A1 - Wirges, Werner A1 - Wegener, Michael A1 - Voronina, Olena A1 - Zirkel, Larissa A1 - Gerhard, Reimund T1 - Optimized preparation of elastically soft, highly piezoelectric, cellular ferroelectrets from nonvoided poly(ethylene terephthalate) films N2 - Electrically charged cellular polymer films can exhibit very high piezoelectric activity and are therefore more and more often employed in advanced electromechanical and electro-acoustical transducers. In this paper, we report an optimized sequence of steps for preparing such ferroelectrets from commercial nonvoided ploy(ethylene terephthalate) (PETP) films by means of foaming with CO2 biaxial mechanical stretching, controlled void inflation, and bipolar electric charging. The nonvoid PETP films foamed with supercritical CO2 at a suitably high pressure and subsequently annealed for stabilization. The cellular foam structure was further optimized by means of well controlled biaxial stretching in a commercial stretcher and sometimes subsequent inflamation in a pressure chamber. Bipolar electric charging of the internal voids was achieved through the application of high electric fields in an SF0 atmosphere. The new optimized PETP ferroelectric exhibit quite large piezoelectric coefficients up to almost 500 pCN(-1), for which unusually low elastic stiffness of only around 0.3 MPa are essential. The PETP foam ferroelectrics posses unclamped thickenss-extension resonance frequences between approximately 120 and 250 kHz, and are thus highly suitable for several established as well as novel ultrasonic-transductant applications. Y1 - 2007 UR - http://onlinelibrary.wiley.com/doi/10.1002/adfm.200600162/pdf U6 - https://doi.org/10.1002/adfm.200600162 ER - TY - JOUR A1 - Winkler, Eckart A1 - Heinken, Thilo T1 - Spread of an ant-dispersed annual herb : an individual-based simulation study on population development of Melampyrum pratense L. N2 - The paper presents a simulation and parameter-estimation approach for evaluating stochastic patterns of population growth and spread of an annual forest herb, Melampyrum pratense (Orobanchaceae). The survival of a species during large-scale changes in land use and climate will depend, to a considerable extent, on its dispersal and colonisation abilities. Predictions on species migration need a combination of field studies and modelling efforts. Our study on the ability of M. pratense to disperse into so far unoccupied areas is based on experiments in secondary woodland in NE Germany. Experiments started in 1997 at three sites where the species was not yet present, with 300 seeds sown within 1m2. Population development was then recorded until 2001 by mapping of individuals with a resolution of 5 cm. Additional observations considered density dependence of seed production. We designed a spatially explicit individual-based computer simulation model to explain the spatial patterns of population development and to predict future population spread. Besides primary drop of seeds (barochory) it assumed secondary seed transport by ants (myrmecochory) with an exponentially decreasing dispersal tail. An important feature of population-pattern explanation was the simultaneous estimation of both population-growth and dispersal parameters from consistent spatio-temporal data sets. As the simulation model produced stochastic time series and random spatially discrete distributions of individuals we estimated parameters by minimising the expectation of weighted sum of squares. These sums of squares criteria considered population sizes, radial population distributions around the area of origin and distributions of individuals within squares of 25cm×25 cm, the range of density action. Optimal parameter values, together with the precision of the estimates, were obtained from calculating sum of squares in regular grids of parameter values. Our modelling results showed that transport of fractions of seeds by ants over distances of 1-2m was indispensable for explaining the observed population spread that led to distances of at most 8mfrom population origin within 3 years. Projections of population development over four additional years gave a diffusion-like increase of population area without any "outposts". This prediction generated by the simulation model gave a hypothesis which should be revised by additional field observations. Some structural deviations between observations and model output already indicated that for full understanding of population spread the set of dispersal mechanisms assumed in the model may have to be extended by additional features of plant-animal mutualism. Y1 - 2007 UR - http://www.sciencedirect.com/science/journal/03043800 SN - 0304-3800 ER - TY - JOUR A1 - Wilke, Max A1 - Partzsch, G. M. A1 - Welter, E. A1 - Farges, Francois T1 - Redox Reaction In Silicate Melts Monitored By Static In-Situ Fe K-edge XANES Up To 1180 C Y1 - 2007 ER - TY - JOUR A1 - Wilke, Max A1 - Farges, Francois A1 - Partzsch, G. M. A1 - Schmidt, C. A1 - Behrens, Harald T1 - Speciation of Fe in silicate glasses and melts by in-situ XANES spectroscopy Y1 - 2007 ER -