@article{StroehlThomasRadegliaetal.1992, author = {Str{\"o}hl, D. and Thomas, Steffen and Radeglia, R. and Brunn, J. and Kleinpeter, Erich}, title = {13C-NMR-Untersuchungen von Substituenteneffekten in mehrfach substituierten Benz-und Naphthalenderivaten ; Inkrementberechnungen der 13C-chemischen Verschiebungen}, year = {1992}, language = {de} } @article{KleinpeterThomasUhligetal.1993, author = {Kleinpeter, Erich and Thomas, Steffen and Uhlig, G. and Rudorf, Wolf-Dieter}, title = {Study of the distribution of pi-Electrons in Push-Pull Alkenes by 1H an 13C NMR spectroscopy}, year = {1993}, language = {en} } @article{GossnerLewinsohnKahletal.2016, author = {Gossner, Martin M. and Lewinsohn, Thomas M. and Kahl, Tiemo and Grassein, Fabrice and Boch, Steffen and Prati, Daniel and Birkhofer, Klaus and Renner, Swen C. and Sikorski, Johannes and Wubet, Tesfaye and Arndt, Hartmut and Baumgartner, Vanessa and Blaser, Stefan and Bl{\"u}thgen, Nico and B{\"o}rschig, Carmen and Buscot, Francois and Diek{\"o}tter, Tim and Jorge, Leonardo Re and Jung, Kirsten and Keyel, Alexander C. and Klein, Alexandra-Maria and Klemmer, Sandra and Krauss, Jochen and Lange, Markus and M{\"u}ller, J{\"o}rg and Overmann, J{\"o}rg and Pasalic, Esther and Penone, Caterina and Perovic, David J. and Purschke, Oliver and Schall, Peter and Socher, Stephanie A. and Sonnemann, Ilja and Tschapka, Marco and Tscharntke, Teja and T{\"u}rke, Manfred and Venter, Paul Christiaan and Weiner, Christiane N. and Werner, Michael and Wolters, Volkmar and Wurst, Susanne and Westphal, Catrin and Fischer, Markus and Weisser, Wolfgang W. and Allan, Eric}, title = {Land-use intensification causes multitrophic homogenization of grassland communities}, series = {Nature : the international weekly journal of science}, volume = {540}, journal = {Nature : the international weekly journal of science}, publisher = {Nature Publ. Group}, address = {London}, issn = {0028-0836}, doi = {10.1038/nature20575}, pages = {266 -- +}, year = {2016}, abstract = {Land-use intensification is a major driver of biodiversity loss(1,2). Alongside reductions in local species diversity, biotic homogenization at larger spatial scales is of great concern for conservation. Biotic homogenization means a decrease in beta-diversity (the compositional dissimilarity between sites). Most studies have investigated losses in local (alpha)-diversity(1,3) and neglected biodiversity loss at larger spatial scales. Studies addressing beta-diversity have focused on single or a few organism groups (for example, ref. 4), and it is thus unknown whether land-use intensification homogenizes communities at different trophic levels, above-and belowground. Here we show that even moderate increases in local land-use intensity (LUI) cause biotic homogenization across microbial, plant and animal groups, both above- and belowground, and that this is largely independent of changes in alpha-diversity. We analysed a unique grassland biodiversity dataset, with abundances of more than 4,000 species belonging to 12 trophic groups. LUI, and, in particular, high mowing intensity, had consistent effects on beta-diversity across groups, causing a homogenization of soil microbial, fungal pathogen, plant and arthropod communities. These effects were nonlinear and the strongest declines in beta-diversity occurred in the transition from extensively managed to intermediate intensity grassland. LUI tended to reduce local alpha-diversity in aboveground groups, whereas the alpha-diversity increased in belowground groups. Correlations between the alpha-diversity of different groups, particularly between plants and their consumers, became weaker at high LUI. This suggests a loss of specialist species and is further evidence for biotic homogenization. The consistently negative effects of LUI on landscape-scale biodiversity underscore the high value of extensively managed grasslands for conserving multitrophic biodiversity and ecosystem service provision. Indeed, biotic homogenization rather than local diversity loss could prove to be the most substantial consequence of land-use intensification.}, language = {en} } @article{AllanBossdorfDormannetal.2014, author = {Allan, Eric and Bossdorf, Oliver and Dormann, Carsten F. and Prati, Daniel and Gossner, Martin M. and Tscharntke, Teja and Bl{\"u}thgen, Nico and Bellach, Michaela and Birkhofer, Klaus and Boch, Steffen and B{\"o}hm, Stefan and B{\"o}rschig, Carmen and Chatzinotas, Antonis and Christ, Sabina and Daniel, Rolf and Diek{\"o}tter, Tim and Fischer, Christiane and Friedl, Thomas and Glaser, Karin and Hallmann, Christine and Hodac, Ladislav and H{\"o}lzel, Norbert and Jung, Kirsten and Klein, Alexandra-Maria and Klaus, Valentin H. and Kleinebecker, Till and Krauss, Jochen and Lange, Markus and Morris, E. Kathryn and M{\"u}ller, J{\"o}rg and Nacke, Heiko and Pasalic, Esther and Rillig, Matthias C. and Rothenwoehrer, Christoph and Schally, Peter and Scherber, Christoph and Schulze, Waltraud X. and Socher, Stephanie A. and Steckel, Juliane and Steffan-Dewenter, Ingolf and T{\"u}rke, Manfred and Weiner, Christiane N. and Werner, Michael and Westphal, Catrin and Wolters, Volkmar and Wubet, Tesfaye and Gockel, Sonja and Gorke, Martin and Hemp, Andreas and Renner, Swen C. and Sch{\"o}ning, Ingo and Pfeiffer, Simone and K{\"o}nig-Ries, Birgitta and Buscot, Francois and Linsenmair, Karl Eduard and Schulze, Ernst-Detlef and Weisser, Wolfgang W. and Fischer, Markus}, title = {Interannual variation in land-use intensity enhances grassland multidiversity}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {111}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {1}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1312213111}, pages = {308 -- 313}, year = {2014}, abstract = {Although temporal heterogeneity is a well-accepted driver of biodiversity, effects of interannual variation in land-use intensity (LUI) have not been addressed yet. Additionally, responses to land use can differ greatly among different organisms; therefore, overall effects of land-use on total local biodiversity are hardly known. To test for effects of LUI (quantified as the combined intensity of fertilization, grazing, and mowing) and interannual variation in LUI (SD in LUI across time), we introduce a unique measure of whole-ecosystem biodiversity, multidiversity. This synthesizes individual diversity measures across up to 49 taxonomic groups of plants, animals, fungi, and bacteria from 150 grasslands. Multidiversity declined with increasing LUI among grasslands, particularly for rarer species and aboveground organisms, whereas common species and belowground groups were less sensitive. However, a high level of interannual variation in LUI increased overall multidiversity at low LUI and was even more beneficial for rarer species because it slowed the rate at which the multidiversity of rare species declined with increasing LUI. In more intensively managed grasslands, the diversity of rarer species was, on average, 18\% of the maximum diversity across all grasslands when LUI was static over time but increased to 31\% of the maximum when LUI changed maximally over time. In addition to decreasing overall LUI, we suggest varying LUI across years as a complementary strategy to promote biodiversity conservation.}, language = {en} } @article{KurpiersFerronRolandetal.2018, author = {Kurpiers, Jona and Ferron, Thomas and Roland, Steffen and Jakoby, Marius and Thiede, Tobias and Jaiser, Frank and Albrecht, Steve and Janietz, Silvia and Collins, Brian A. and Howard, Ian A. and Neher, Dieter}, title = {Probing the pathways of free charge generation in organic bulk heterojunction solar cells}, series = {Nature Communications}, volume = {9}, journal = {Nature Communications}, publisher = {Nature Publ. Group}, address = {London}, issn = {2041-1723}, doi = {10.1038/s41467-018-04386-3}, pages = {11}, year = {2018}, abstract = {The fact that organic solar cells perform efficiently despite the low dielectric constant of most photoactive blends initiated a long-standing debate regarding the dominant pathways of free charge formation. Here, we address this issue through the accurate measurement of the activation energy for free charge photogeneration over a wide range of photon energy, using the method of time-delayed collection field. For our prototypical low bandgap polymer:fullerene blends, we find that neither the temperature nor the field dependence of free charge generation depend on the excitation energy, ruling out an appreciable contribution to free charge generation though hot carrier pathways. On the other hand, activation energies are on the order of the room temperature thermal energy for all studied blends. We conclude that charge generation in such devices proceeds through thermalized charge transfer states, and that thermal energy is sufficient to separate most of these states into free charges.}, language = {en} } @article{SiniSchubertRiskoetal.2018, author = {Sini, Gjergji and Schubert, Marcel and Risko, Chad and Roland, Steffen and Lee, Olivia P. and Chen, Zhihua and Richter, Thomas V. and Dolfen, Daniel and Coropceanu, Veaceslav and Ludwigs, Sabine and Scherf, Ullrich and Facchetti, Antonio and Frechet, Jean M. J. and Neher, Dieter}, title = {On the Molecular Origin of Charge Separation at the Donor-Acceptor Interface}, series = {Advanced energy materials}, volume = {8}, journal = {Advanced energy materials}, number = {12}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1614-6832}, doi = {10.1002/aenm.201702232}, pages = {15}, year = {2018}, abstract = {Fullerene-based acceptors have dominated organic solar cells for almost two decades. It is only within the last few years that alternative acceptors rival their dominance, introducing much more flexibility in the optoelectronic properties of these material blends. However, a fundamental physical understanding of the processes that drive charge separation at organic heterojunctions is still missing, but urgently needed to direct further material improvements. Here a combined experimental and theoretical approach is used to understand the intimate mechanisms by which molecular structure contributes to exciton dissociation, charge separation, and charge recombination at the donor-acceptor (D-A) interface. Model systems comprised of polythiophene-based donor and rylene diimide-based acceptor polymers are used and a detailed density functional theory (DFT) investigation is performed. The results point to the roles that geometric deformations and direct-contact intermolecular polarization play in establishing a driving force ( energy gradient) for the optoelectronic processes taking place at the interface. A substantial impact for this driving force is found to stem from polymer deformations at the interface, a finding that can clearly lead to new design approaches in the development of the next generation of conjugated polymers and small molecules.}, language = {en} } @article{HeistermannBogenaFranckeetal.2022, author = {Heistermann, Maik and Bogena, Heye and Francke, Till and G{\"u}ntner, Andreas and Jakobi, Jannis and Rasche, Daniel and Schr{\"o}n, Martin and D{\"o}pper, Veronika and Fersch, Benjamin and Groh, Jannis and Patil, Amol and P{\"u}tz, Thomas and Reich, Marvin and Zacharias, Steffen and Zengerle, Carmen and Oswald, Sascha}, title = {Soil moisture observation in a forested headwater catchment: combining a dense cosmic-ray neutron sensor network with roving and hydrogravimetry at the TERENO site W{\"u}stebach}, series = {Earth system science data : ESSD}, volume = {14}, journal = {Earth system science data : ESSD}, number = {5}, publisher = {Copernicus}, address = {Katlenburg-Lindau}, issn = {1866-3516}, doi = {10.5194/essd-14-2501-2022}, pages = {2501 -- 2519}, year = {2022}, abstract = {Cosmic-ray neutron sensing (CRNS) has become an effective method to measure soil moisture at a horizontal scale of hundreds of metres and a depth of decimetres. Recent studies proposed operating CRNS in a network with overlapping footprints in order to cover root-zone water dynamics at the small catchment scale and, at the same time, to represent spatial heterogeneity. In a joint field campaign from September to November 2020 (JFC-2020), five German research institutions deployed 15 CRNS sensors in the 0.4 km2 W{\"u}stebach catchment (Eifel mountains, Germany). The catchment is dominantly forested (but includes a substantial fraction of open vegetation) and features a topographically distinct catchment boundary. In addition to the dense CRNS coverage, the campaign featured a unique combination of additional instruments and techniques: hydro-gravimetry (to detect water storage dynamics also below the root zone); ground-based and, for the first time, airborne CRNS roving; an extensive wireless soil sensor network, supplemented by manual measurements; and six weighable lysimeters. Together with comprehensive data from the long-term local research infrastructure, the published data set (available at https://doi.org/10.23728/b2share.756ca0485800474e9dc7f5949c63b872; Heistermann et al., 2022) will be a valuable asset in various research contexts: to advance the retrieval of landscape water storage from CRNS, wireless soil sensor networks, or hydrogravimetry; to identify scale-specific combinations of sensors and methods to represent soil moisture variability; to improve the understanding and simulation of land-atmosphere exchange as well as hydrological and hydrogeological processes at the hillslope and the catchment scale; and to support the retrieval of soil water content from airborne and spaceborne remote sensing platforms.}, language = {en} } @misc{ZeuschnerParpiievPezeriletal.2019, author = {Zeuschner, Steffen Peer and Parpiiev, Tymur and Pezeril, Thomas and Hillion, Arnaud and Dumesnil, Karine and Anane, Abdelmadjid and Pudell, Jan-Etienne and Willig, Lisa and R{\"o}ssle, Matthias and Herzog, Marc and Reppert, Alexander von and Bargheer, Matias}, title = {Tracking picosecond strain pulses in heterostructures that exhibit giant magnetostriction}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-naturwissenschaftliche Reihe}, number = {706}, issn = {1866-8372}, doi = {10.25932/publishup-42845}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-428457}, pages = {9}, year = {2019}, abstract = {We combine ultrafast X-ray diffraction (UXRD) and time-resolved Magneto-Optical Kerr Effect (MOKE) measurements to monitor the strain pulses in laser-excited TbFe2/Nb heterostructures. Spatial separation of the Nb detection layer from the laser excitation region allows for a background-free characterization of the laser-generated strain pulses. We clearly observe symmetric bipolar strain pulses if the excited TbFe2 surface terminates the sample and a decomposition of the strain wavepacket into an asymmetric bipolar and a unipolar pulse, if a SiO2 glass capping layer covers the excited TbFe2 layer. The inverse magnetostriction of the temporally separated unipolar strain pulses in this sample leads to a MOKE signal that linearly depends on the strain pulse amplitude measured through UXRD. Linear chain model simulations accurately predict the timing and shape of UXRD and MOKE signals that are caused by the strain reflections from multiple interfaces in the heterostructure.}, language = {en} } @article{ZeuschnerParpiievPezeriletal.2019, author = {Zeuschner, Steffen Peer and Parpiiev, Tymur and Pezeril, Thomas and Hillion, Arnaud and Dumesnil, Karine and Anane, Abdelmadjid and Pudell, Jan-Etienne and Willig, Lisa and R{\"o}ssle, Matthias and Herzog, Marc and Reppert, Alexander von and Bargheer, Matias}, title = {Tracking picosecond strain pulses in heterostructures that exhibit giant magnetostriction}, series = {Structural Dynamics}, volume = {6}, journal = {Structural Dynamics}, number = {2}, publisher = {AIP Publishing LLC}, address = {Melville, NY}, issn = {2329-7778}, doi = {10.1063/1.5084140}, pages = {9}, year = {2019}, abstract = {We combine ultrafast X-ray diffraction (UXRD) and time-resolved Magneto-Optical Kerr Effect (MOKE) measurements to monitor the strain pulses in laser-excited TbFe2/Nb heterostructures. Spatial separation of the Nb detection layer from the laser excitation region allows for a background-free characterization of the laser-generated strain pulses. We clearly observe symmetric bipolar strain pulses if the excited TbFe2 surface terminates the sample and a decomposition of the strain wavepacket into an asymmetric bipolar and a unipolar pulse, if a SiO2 glass capping layer covers the excited TbFe2 layer. The inverse magnetostriction of the temporally separated unipolar strain pulses in this sample leads to a MOKE signal that linearly depends on the strain pulse amplitude measured through UXRD. Linear chain model simulations accurately predict the timing and shape of UXRD and MOKE signals that are caused by the strain reflections from multiple interfaces in the heterostructure.}, language = {en} }