Refine
Year of publication
Document Type
- Article (20261)
- Doctoral Thesis (3100)
- Postprint (2090)
- Monograph/Edited Volume (1186)
- Other (638)
- Review (580)
- Conference Proceeding (293)
- Preprint (230)
- Part of a Book (211)
- Working Paper (130)
Language
- English (28929) (remove)
Is part of the Bibliography
- yes (28929) (remove)
Keywords
- climate change (167)
- Germany (96)
- machine learning (76)
- diffusion (74)
- German (66)
- Arabidopsis thaliana (64)
- anomalous diffusion (58)
- stars: massive (56)
- Climate change (54)
- Holocene (54)
Institute
- Institut für Physik und Astronomie (4793)
- Institut für Biochemie und Biologie (4611)
- Institut für Geowissenschaften (3240)
- Institut für Chemie (2831)
- Institut für Mathematik (1555)
- Department Psychologie (1386)
- Institut für Ernährungswissenschaft (1005)
- Department Linguistik (910)
- Wirtschaftswissenschaften (825)
- Institut für Informatik und Computational Science (792)
- Institut für Umweltwissenschaften und Geographie (733)
- Department Sport- und Gesundheitswissenschaften (686)
- Mathematisch-Naturwissenschaftliche Fakultät (536)
- Institut für Anglistik und Amerikanistik (467)
- Sozialwissenschaften (439)
- Strukturbereich Kognitionswissenschaften (401)
- Extern (388)
- Hasso-Plattner-Institut für Digital Engineering gGmbH (346)
- Hasso-Plattner-Institut für Digital Engineering GmbH (344)
- Fachgruppe Betriebswirtschaftslehre (280)
- Fachgruppe Politik- & Verwaltungswissenschaft (269)
- Humanwissenschaftliche Fakultät (255)
- Department Erziehungswissenschaft (194)
- Historisches Institut (177)
- Fachgruppe Volkswirtschaftslehre (166)
- Institut für Romanistik (162)
- Institut für Germanistik (154)
- Philosophische Fakultät (129)
- Institut für Jüdische Studien und Religionswissenschaft (115)
- Öffentliches Recht (112)
- Interdisziplinäres Zentrum für Dynamik komplexer Systeme (88)
- Wirtschafts- und Sozialwissenschaftliche Fakultät (86)
- Fachgruppe Soziologie (73)
- Center for Economic Policy Analysis (CEPA) (71)
- Fakultät für Gesundheitswissenschaften (65)
- Institut für Philosophie (63)
- Strukturbereich Bildungswissenschaften (59)
- Department für Inklusionspädagogik (53)
- Institut für Slavistik (50)
- Department Grundschulpädagogik (43)
- MenschenRechtsZentrum (43)
- Institut für Künste und Medien (41)
- Bürgerliches Recht (31)
- Institut für Jüdische Theologie (31)
- Interdisziplinäres Zentrum für Dünne Organische und Biochemische Schichten (26)
- Klassische Philologie (22)
- Referat für Presse- und Öffentlichkeitsarbeit (22)
- Zentrum für Gerechtigkeitsforschung (21)
- Potsdam Research Institute for Multilingualism (PRIM) (18)
- Vereinigung für Jüdische Studien e. V. (18)
- Hochschulambulanz (14)
- Lehreinheit für Wirtschafts-Arbeit-Technik (13)
- Potsdam Institute for Climate Impact Research (PIK) e. V. (13)
- Interdisziplinäres Zentrum für Biopolymere (11)
- Zentrum für Lehrerbildung und Bildungsforschung (ZeLB) (11)
- Digital Engineering Fakultät (10)
- Sonderforschungsbereich 632 - Informationsstruktur (10)
- Potsdam Transfer - Zentrum für Gründung, Innovation, Wissens- und Technologietransfer (9)
- Strafrecht (9)
- Zentrum für Umweltwissenschaften (8)
- Berlin Potsdam Research Group "The International Rule of Law - Rise or Decline?" (7)
- Department Musik und Kunst (7)
- Juristische Fakultät (6)
- Multilingualism (6)
- Zentrum für Qualitätsentwicklung in Lehre und Studium (ZfQ) (6)
- Abraham Geiger Kolleg gGmbH (5)
- Zentrum für Lern- und Lehrforschung (5)
- Forschungsbereich „Politik, Verwaltung und Management“ (4)
- Moses Mendelssohn Zentrum für europäisch-jüdische Studien e. V. (4)
- Patholinguistics/Neurocognition of Language (4)
- Akademie für Psychotherapie und Interventionsforschung GmbH (3)
- Gesundheitsmanagement (3)
- Institut für Religionswissenschaft (3)
- Interdisziplinäres Zentrum für Kognitive Studien (3)
- Psycholinguistics and Neurolinguistics (3)
- Zentrum für Sprachen und Schlüsselkompetenzen (Zessko) (3)
- An-Institute (2)
- DV und Statistik Wirtschaftswissenschaften (2)
- Senat (2)
- UP Transfer (2)
- WeltTrends e.V. Potsdam (2)
- Zentrum für Australienforschung (2)
- Applied Computational Linguistics (1)
- Botanischer Garten (1)
- Foundations of Computational Linguistics (1)
- Institut für Lebensgestaltung-Ethik-Religionskunde (1)
- Interdisziplinäres Zentrum für Massenspektronomie von Biopolymeren (1)
- Interdisziplinäres Zentrum für Musterdynamik und Angewandte Fernerkundung (1)
- Kommissionen des Senats (1)
- Kommunalwissenschaftliches Institut (1)
- Language Acquisition (1)
- Organe und Gremien (1)
- Phonology & Phonetics (1)
- Syntax, Morphology & Variability (1)
- Theodor-Fontane-Archiv (1)
- Weitere Einrichtungen (1)
How related are the ergodic properties of the over- and underdamped Langevin equations driven by fractional Gaussian noise? We here find that for massive particles performing fractional Brownian motion (FBM) inertial effects not only destroy the stylized fact of the equivalence of the ensemble-averaged mean-squared displacement (MSD) to the time-averaged MSD (TAMSD) of overdamped or massless FBM, but also dramatically alter the values of the ergodicity-breaking parameter (EB). Our theoretical results for the behavior of EB for underdamped or massive FBM for varying particle mass m, Hurst exponent H, and trace length T are in excellent agreement with the findings of stochastic computer simulations. The current results can be of interest for the experimental community employing various single-particle-tracking techniques and aiming at assessing the degree of nonergodicity for the recorded time series (studying, e.g., the behavior of EB versus lag time). To infer FBM as a realizable model of anomalous diffusion for a set single-particle-tracking data when massive particles are being tracked, the EBs from the data should be compared to EBs of massive (rather than massless) FBM.
In recent years, there have been a growing number of online and offline attacks linked to a loosely connected network of misogynist and antifeminist online communities called ‘the manosphere’. Since 2016, the ideas spread among and by groups of the manosphere have also become more closely aligned with those of other Far-Right online networks. In this commentary, I explore the role of what I term ‘evidence-based misogyny’ for mobilization and radicalization into the antifeminist and misogynist subcultures of the manosphere. Evidence-based misogyny is a discursive strategy, whereby members of the manosphere refer to (and misinterpret) knowledge in the form of statistics, studies, news items and pop-culture and mimic accepted methods of knowledge presentation to support their essentializing, polarizing views about gender relations in society. Evidence-based misogyny is a core aspect for manosphere-related mobilization as it provides a false sense of authority and forges a collective identity, which is framed as a supposed ‘alternative’ to mainstream gender knowledge. Due to its core function to justify and confirm the misogynist sentiments of users, evidence-based misogyny serves as connector between the manosphere and both mainstream conservative as well as other Far-Right and conspiratorial discourses.
Marine sedimentary archives are routinely used to reconstruct past environmental changes. In many cases, bioturbation and sedimentary mixing affect the proxy time-series and the age-depth relationship. While idealized models of bioturbation exist, they usually assume homogeneous mixing, thus that a single sample is representative for the sediment layer it is sampled from.
However, it is largely unknown to which extent this assumption holds for sediments used for paleoclimate reconstructions.
To shed light on
1) the age-depth relationship and its full uncertainty,
2) the magnitude of mixing processes affecting the downcore proxy variations, and
3) the representativity of the discrete sample for the sediment layer, we designed and performed a case study on South China Sea sediment material which was collected using a box corer and which covers the last glacial cycle.
Using the radiocarbon content of foraminiferal tests as a tracer of time, we characterize the spatial age-heterogeneity of sediments in a three-dimensional setup. In total, 118 radiocarbon measurements were performed on defined small- and large-volume bulk samples ( similar to 200 specimens each) to investigate the horizontal heterogeneity of the sediment. Additionally, replicated measurements on small numbers of specimens (10 x 5 specimens) were performed to assess the heterogeneity within a sample volume. Visual assessment of X-ray images and a quantitative assessment of the mixing strength show typical mixing from bioturbation corresponding to around 10 cm mixing depth.
Notably, our 3D radiocarbon distribution reveals that the horizontal heterogeneity (up to 1,250 years), contributing to the age uncertainty, is several times larger than the typically assumed radiocarbon based age-model error (single errors up to 250 years). Furthermore, the assumption of a perfectly bioturbated layer with no mixing underneath is not met.
Our analysis further demonstrates that the age-heterogeneity might be a function of sample size; smaller samples might contain single features from the incomplete mixing and are thus less representative than larger samples.
We provide suggestions for future studies, optimal sampling strategies for quantitative paleoclimate reconstructions and realistic uncertainty in age models, as well as discuss possible implications for the interpretation of paleoclimate records.
In this study, the kinetics of the adsorption of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F(4)TCNQ) on the surface of Ag nanoparticles (Ag NPs) in chloroform has been intensively investigated, as molecular doping is known to play a crucial role in organic electronic devices. Based on the results obtained from UV-visible (vis)-near-infrared (NIR) absorption spectroscopy, cryogenic transmission electron microscopy, scanning nanobeam electron diffraction, and electron energy loss spectroscopy, a two-step interaction kinetics has been proposed for the Ag NPs and F(4)TCNQ molecules, which includes the first step of electron transfer from Ag NPs to F(4)TCNQ indicated by the ionization of F(4)TCNQ and the second step of the formation of a Ag-F(4)TCNQ complex. The whole process has been followed via UV-vis-NIR absorption spectroscopy, which reveals distinct kinetics at two stages: the instantaneous ionization and the long-term complex formation. The kinetics and the influence of the molar ratio of Ag NPs/F(4)TCNQ molecules on the interaction between Ag NPs and F(4)TCNQ molecules in an organic solution are reported herein for the first time. Furthermore, the control experiment with silica-coated Ag NPs manifests that the charge transfer at the surface between Ag NPs and F(4)TCNQ molecules is prohibited by a silica layer of 18 nm.
The within-site variability in site response is the randomness in site response at a given site from different earthquakes and is treated as aleatory variability in current seismic hazard/risk analyses.
In this study, we investigate the single-station variability in linear site response at K-NET and KiK-net stations in Japan using a large number of earthquake recordings.
We found that the standard deviation of the horizontal-to-vertical Fourier spectral ratio at individual sites, that is single-station horizontal-to-vertical spectral ratio (HVSR) sigma sigma(HV,s), approximates the within-site variability in site response quantified using surface-to-borehole spectral ratios (for oscillator frequencies higher than the site fundamental frequency) or empirical ground-motion models.
Based on this finding, we then utilize the single-station HVSR sigma as a convenient tool to study the site-response variability at 697 KiK-net and 1169 K-NET sites.
Our results show that at certain frequencies, stiff, rough and shallow sites, as well as small and local events tend to have a higher sigma(HV,s).
However, when being averaged over different sites, the single-station HVSR sigma, that is sigma(HV), increases gradually with decreasing frequency. In the frequency range of 0.25-25 Hz, sigma(HV) is centred at 0.23-0.43 in ln scales (a linear scale factor of 1.26-1.54) with one standard deviation of less than 0.1. sigma(HV) is quite stable across different tectonic regions, and we present a constant, as well as earthquake magnitude- and distance-dependent sigma(HV) models.
The power of opposition
(2022)
Proposing a novel way to look at the consolidation of democratic regimes, this book presents important theoretical and empirical contributions to the study of democratic consolidation, legislative organization, and public opinion.
Theoretically, Simone Wegmann brings legislatures into focus as the main body representing both winners and losers of democratic elections. Empirically, Wegmann shows that the degree of policy-making power of opposition players varies considerably between countries. Using survey data from the CSES, the ESS, and the LAPOP and systematically analyzing more than 50 legislatures across the world and the specific rights they grant to opposition players during the policy-making process, Wegmann demonstrates that neglecting the curial role of the legislature in a democratic setting can only lead to an incomplete assessment of the importance of institutions for democratic consolidation.
The Power of Opposition will be of great interest to scholars of comparative politics, especially those working on questions related to legislative organization, democratic consolidation, and/or public opinion.
We employ Langevin-dynamics simulations to unveil non-Brownian and non-Gaussian center-of-mass self-diffusion of massive flexible dumbbell-shaped particles in crowded two-dimensional solutions. We study the intradumbbell dynamics of the relative motion of the two constituent elastically coupled disks. Our main focus is on effects of the crowding fraction phi and of the particle structure on the diffusion characteristics. We evaluate the time-averaged mean-squared displacement (TAMSD), the displacement probability-density function (PDF), and the displacement autocorrelation function (ACF) of the dimers. For the TAMSD at highly crowded conditions of dumbbells, e.g., we observe a transition from the short-time ballistic behavior, via an intermediate subdiffusive regime, to long-time Brownian-like spreading dynamics. The crowded system of dimers exhibits two distinct diffusion regimes distinguished by the scaling exponent of the TAMSD, the dependence of the diffusivity on phi, and the features of the displacement-ACF. We attribute these regimes to a crowding-induced transition from viscous to viscoelastic diffusion upon growing phi. We also analyze the relative motion in the dimers, finding that larger phi suppress their vibrations and yield strongly non-Gaussian PDFs of rotational displacements. For the diffusion coefficients D(phi) of translational and rotational motion of the dumbbells an exponential decay with phi for weak and a power-law variation D(phi) proportional to (phi - phi(star))(2.4) for strong crowding is found. A comparison of simulation results with theoretical predictions for D(phi) is discussed and some relevant experimental systems are overviewed.
Sven Siefken und Hilmar Rommetvedt (Hrsg.). 2021. Parliamentary committees in the policy process
(2023)
In this study we present a novel method for the automatic detection of minerals and elements using hyperspectral transmittance imaging microscopy measurements of complete thin sections (HyperTIM).
This is accomplished by using a hyperspectral camera system that operates in the visible and near-infrared (VNIR) range with a specifically designed sample holder, scanning setup, and a microscope lens.
We utilize this method on a monazite ore thin section from Steenkampskraal (South Africa), which we analyzed for the rare earth element (REE)-bearing mineral monazite ((Ce,Nd,La)PO4), with high concentrations of Nd. The transmittance analyses with the hyperspectral VNIR camera can be used to identify REE minerals and Nd in thin sections.
We propose a three-point band depth index, the Nd feature depth index (NdFD), and its related product the Nd band depth index (NdBDI), which enables automatic mineral detection and classification for the Nd-bearing monazites in thin sections. In combination with the average concentration of the relative Nd content, it permits a destruction-free, total concentration calculation for Nd across the entire thin section.