University of Siegen
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Publication Access status: Open Access , Sprachbildende Schulbuchaufgaben im Fachunterricht - Qualitative Inhaltsanalyse und Intervention(2026)In diesem Open-Access-Buch wird ein zentrales Problem schulischer Praxis aufgegriffen: Schulbuchaufgaben können für Schüler:innen schwer verständlich sein und nur begrenzte Unterstützung für den Erwerb bildungssprachlicher Kompetenzen bieten. Auf Basis einer Mixed-Methods-Studie mit 1.357 Aufgaben aus den Fächern Wirtschaft-Politik und Physik wird untersucht, welches Lern- und Schreibpotenzial sie aufweisen und wie sich dieses gezielt ausbauen lässt. Eine systematische Aufgabenanalyse wird dabei mit einer Interventionsstudie in einem hybriden Lernsetting verbunden. Die Ergebnisse zeigen sowohl fachübergreifende Herausforderungen der Aufgabenkultur als auch fachspezifische Unterschiede. Zugleich wird deutlich, wie schreibförderlich gestaltete Aufgaben fachliches und sprachliches Lernen produktiv verbinden können. Der Band richtet sich an Forschende, Lehrkräfte, Schulbuchautor:innen und Studierende, die Unterricht sprachbildend gestalten und Lernumgebungen – einschließlich generativer KI – reflektiert und wirksam einsetzen möchten.Source Type:Doctoral Thesis32 6 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Inclusive $$\overline{B}\to {X}_s{\ell}^{+}{\ell}^{-}$$ at the LHC: theory predictions and new-physics reachWe present theoretical predictions for observables in inclusive $\overline{B}\to {X}_s{\ell}^{+}{\ell}^{-}$ suitable for measurements at hadron colliders through a sum-over-exclusive approach. At low $q^{2}$ we calculate the branching ratio and three angular observables. At high $q^{2}$ we provide the branching ratio and the ratio of the $\overline{B}\to {X}_s{\ell}^{+}{\ell}^{-}$ rate with respect to the inclusive $\overline{B}\to {X}_u\ell \overline{\nu}$ rate with the same phase-space cut. We compare our predictions to the B factory measurements and also to an extraction of the experimental rate through a sum-over-exclusive method using branching ratios of the exclusive $\overline{B}\to {K}^{\left(\ast \right)}{\mu}^{+}{\mu}^{-}$ modes measured at LHCb. We find a consistent picture comparing Standard Model theory and experiment. As such, our analysis does not support a recent claim about a deficit in the inclusive branching ratio in the high- $q^{2}$ region. Finally, we present current model-independent bounds on new physics and emphasize the potential of complementary analyses of $\overline{B}\to {X}_s{\ell}^{+}{\ell}^{-}$ at Belle II and the LHC.Source Type:Article3 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Two-color four-wave mixing contribution to an electrostrictive laser-induced grating signal in CO<sub>2</sub>–N<sub>2</sub> mixtures and gas diagnostics(2023); ; Multiparameter determination in the gas phase using the versatile laser-induced grating (LIG) technique is a challenging task due to interdependence of observables on multiple thermodynamic parameters. In CO 2 -N 2 mixtures, simultaneous determination of species concentration and gas temperature can be achieved by using an additional CO 2 concentration-dependent contribution to the LIG signal, which appears if 1064 nm pump pulses are employed. This contribution can be attributed to a direct, quasi-resonant two-color four-wave mixing (TCFWM) of the pump and probe radiations in CO 2 . A detailed study of the laser power and beam polarization, as well as mixture composition, pressure, and temperature dependencies of the TCFWM intensity relative to that of the LIG signal, allowed for the formulation of analytical relations enabling simultaneous mixture composition and temperature determination.Source Type:Article4 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Analysis of the sound insulation performance of periodic wall structures by a virtual acoustic laboratoryThe propagation of acoustic waves in periodic structures, also known as phononic crystals or PCs, is prohibited in certain frequency ranges, which are referred to as the frequency band-gaps. The existence, the location and the width of the frequency band-gaps are mainly determined by the geometrical parameters and the material properties of the PCs. In this work, a virtual acoustic laboratory based on a fully coupled fluid-structure interaction (FSI) model is developed to determine the sound insulation capacity of one-dimensional (1D) and two-dimensional (2D) periodic walls. The FSI model is discretized using the frequency-domain spectral element method (FDSEM), which is an advanced finite element method (FEM) using special high-order shape functions. Following the guidelines of the ISO10140, the setup of the developed FSI model allows us to take into account the essential physical phenomena, especially the interaction of the wall structure with the fluid domains (air). The FSI model based on the FDSEM increases the computational efficiency and accuracy in comparison with the standard FEM. Several numerical examples will be presented and discussed to show that the designed periodic walls in certain frequency ranges within the band-gaps may exhibit much better sound insulation capabilities than monolithic walls.Source Type:Article3 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Fluorescence and Phosphorescence Energy Transfer in Cucurbituril‐Based Supramolecular Systems(2023)1 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Bis‐ and Tris‐norbornadienes with High Energy Densities for Efficient Molecular Solar Thermal Energy StorageMolecular solar thermal energy storage (MOST) systems can convert, store and release solar energy in chemical bonds, i.e., as chemical energy. In this work, phenyl‐ and naphthyl‐linked bis‐ and tris‐norbornadienes are presented as promising MOST systems with very high energy densities. The substrates were synthesized by Suzuki–Miyaura coupling reactions and their absorption properties and characteristic parameters for MOST applications were investigated. The norbornadiene derivatives showed absorption onsets of up to 386 nm and photoisomerization quantum yields of 56 % per photoisomerization event. The resulting quadricyclane products have half‐lifes up to 14 d and very high energy densities of up to 734 kJ/kg. Overall, these norbornadienes fulfill necessary criteria for an optimal MOST system and are, therefore, a highly promising basis for the development of materials for efficient solar energy conversion and storage.Source Type:Article3 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Optical system characterization in Fourier ptychographic microscopy(2024); ; Fourier ptychographic microscopy (FPM) is a recent technique to overcome the diffraction limit of a low numerical aperture (NA) objective lens by algorithmic post-processing of several low-resolution images. It can increase the space-bandwidth product of an optical system by computationally combining images captured under different illumination conditions. Vignetting determines the spatial extent of the bright and dark regions in the captured images. State-of-the-art analyses treat vignetting as a nuisance that needs to be reduced or excluded from algorithmic consideration using ad hoc decision rules. In contrast, this work investigates vignetting effects as a tool to infer a range of properties of the optical system. Generally, the goal of the FPM reconstruction algorithm is to achieve results that closely resemble the actual specimen at the highest resolution possible. However, as the optimization process does not necessarily guarantee a unique solution, we identify system properties that support alignment between computational predictions and empirical observations, potentially leading to a more accurate and reliable analysis. To achieve this, we characterize the individual system components of the experimental setup and compare experimental data to both, geometrical and wave optical simulations. We demonstrate that using vignetting as an analytical tool enables the modeling of the geometric and coherence properties of the optical system as evidenced by the good agreement between our simulation and experiment.Source Type:Article1 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Analysis of the {\psi (3770)} resonance in line with unitarity and analyticity constraints(2024); ; ; We study the inclusive and exclusive cross sections of $e^+e^-\rightarrow \text {hadrons}$ for center-of-mass energies between 3.70 and $3.83\,\,\textrm{GeV}$ to infer the mass, width, and couplings of the $\psi (3770)$ resonance. By using a coupled-channel K -matrix approach, we setup our analysis to respect unitarity and the analyticity properties of the underlying scattering amplitudes. We fit several models to the full dataset and identify our nominal results through a statistical model comparison. We find that, accounting for the interplay between the $\psi (2S)$ and the $\psi (3770)$, no further pole is required to describe the $\psi (3770)$ line shape. In particular we derive from the pole location $M_{\psi (3770)}~=~3778.8~\pm ~0.3~\,\textrm{MeV}$ and $\varGamma _{\psi (3770)}~=~25.0~\pm ~0.5~\,\textrm{MeV}$. Moreover, we find the decay to $D^+D^-$ and $D^0\bar{D}^0$ to be consistent with isospin symmetry and derive an upper bound on the branching ratio ${\mathcal {B}}(\psi (3770) \rightarrow \text {non-}D\bar{D}) < 6\%$ at $90\%$ probability.Source Type:Article1 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , Beyond fads and magic bullets: The promise of behavioral approaches in development economics(2024)The history of development economics has been portrayed as a succession of fads and magic bullets. This study inquires whether behavioral approaches to economic development are destined to become such a fad or whether they have long‐lasting contributions to offer. I first show that behavioral development economics is not a cohesive field with a consensual definition and propose to distinguish three different views of behavioral development economics: the scarcity view, the non‐optimal behavior view, and the psycho‐social‐cultural view. I provide a systematic review of publications in the field of behavioral development economics from 2000 to 2021, distinguishing these three fields. The nonoptimal view has been, by far, the dominant view, and risk and time preferences stand out as the single‐most studied behavioral mechanisms. Finally, I argue that the sub‐field's ability to advance the understanding of behavior relevant to the persistence or alleviation of poverty depends crucially on the inclusion of the psycho‐social‐cultural view. This view has important contributions to offer in terms of (1) the understanding of seemingly nonrational behavior, (2) the identification and measurement of behavioral mechanisms, and (3) the understanding of conditions of external validity, and should be embraced more enthusiastically.Source Type:Article1 - Some of the metrics are blocked by yourconsent settings
Publication Access status: Metadata only , 1
