@inbook{45471, author = {{Vogelsang, Christoph and Borowski, Andreas and Kulgemeyer, Christoph and Riese, Josef and Reinhold, Peter and Schecker, Horst and Buschütter, David and Enkrott, Patrick and Kempin, Maren and Schröder, Jan}}, booktitle = {{Student Learning Outcomes Assessment in Higher Education – Perspectives, Concepts and Approaches for Research, Transfer and Implementation (KoKoHs Working Papers, 12)}}, editor = {{Zlatkin-Troitschanskaia, Olga and Toepper, Miriam and Pant, Hans Anand and Lautenbach, Corinna and Kuhn, Christiane}}, pages = {{40--43}}, title = {{{Performance-Oriented Testing and Training in Teacher Education}}}, year = {{2019}}, } @inproceedings{45478, author = {{Vogelsang, Christoph and Riese, Josef and Borowski, Andreas and Kulgemeyer, Christoph}}, booktitle = {{Naturwissenschaftliche Bildung als Grundlage für berufliche und gesellschaftliche Teilhabe. Gesellschaft für Didaktik der Chemie und Physik. Jahrestagung in Kiel 2018}}, editor = {{Maurer, Christian}}, pages = {{345--348}}, title = {{{Profile-P+: Kompetenz und Performanz im Lehramtsstudium Physik}}}, volume = {{39}}, year = {{2019}}, } @inproceedings{45477, author = {{Schröder, Jan and Vogelsang, Christoph and Riese, Josef}}, booktitle = {{Naturwissenschaftliche Bildung als Grundlage für berufliche und gesellschaftliche Teilhabe. Gesellschaft für Didaktik der Chemie und Physik. Jahrestagung in Kiel 2018}}, editor = {{Maurer, Christian}}, pages = {{353--356}}, title = {{{Erfassung der Fähigkeit zur Unterrichtsplanung im Physikunterricht}}}, volume = {{39}}, year = {{2019}}, } @article{62775, author = {{Schowtjak, Alexander and Wang, Shuhan and Hering, Oliver and Clausmeyer, Till and Lohmar, Johannes and Schulte, Robin and Ostwald, Richard and Hirt, Gerhard and Tekkaya, A. Erman}}, issn = {{0944-6524}}, journal = {{Production Engineering}}, number = {{1}}, pages = {{33--41}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Prediction and analysis of damage evolution during caliber rolling and subsequent cold forward extrusion}}}, doi = {{10.1007/s11740-019-00935-x}}, volume = {{14}}, year = {{2019}}, } @article{62779, author = {{Ostwald, Richard and Kuhl, Ellen and Menzel, Andreas}}, issn = {{0178-7675}}, journal = {{Computational Mechanics}}, number = {{3}}, pages = {{847--877}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{On the implementation of finite deformation gradient-enhanced damage models}}}, doi = {{10.1007/s00466-019-01684-5}}, volume = {{64}}, year = {{2019}}, } @inproceedings{23756, abstract = {{Creativity is perceived to be one of the core competences to succeed in the modern world. It is connected to art, music, dancing, etc., but there is just little insight into the role of creativity in science. As data analysis plays a major role in science, creative thinking has to be used to form theories out of observations. This study uses models-of-data to represent the mental model of the students. Within models-of-data different observations and previous knowledge are linked through different types of links, e.g. causal links. The goal of this study was to examine the creative aspect of data evaluation in presence of anomalous data. The students were confronted with two experiments which contradicted each other with regard to the underlying theory. Afterwards the students were asked to decide about their favored theory and reasoning about their choice in their lab reports. The model-of-data, which was reconstructed from the lab reports of the students, was used to extract creative aspects in the mental modelling process. Furthermore, a pre-post-questionnaire on epistemological beliefs of the students was conducted. Students mostly acquired an unscientific view on epistemology in school. The question was whether the confrontation with anomalous data and the triggering of creative modelling processes have any influence on this. The results show that most students did not take anomalous data into account in their modelling processes. They did either not recognise or just ignore the data. Just a few students worked on their theory because of the new, contradictory data. The students working on their theory scored higher in the post-questionnaire, so a positive effect of creativity on scientific epistemology can be assumed. Thus, creativity obviously gets a part of science and should be taught in school science in order to make students aware of their own creative potential.}}, author = {{Pollmeier, Pascal and Fechner, Sabine}}, booktitle = {{The beauty and pleasure of understanding: engaging with contemporary challenges through science education. Electronic Proceedings of the ESERA 2019 Conference. }}, editor = {{Levrini, Olivia and Tasquir, Giulia and Kaya, Ebru and Vesterinen, Veli-Matti}}, keywords = {{epistemology, conceptual change, anomalous data}}, location = {{Bologna}}, pages = {{751--759}}, publisher = {{ALMA MATER STUDIORUM - University of Bologna}}, title = {{{Creativity in data analysis through confrontation with anomalous data}}}, year = {{2019}}, } @article{20578, author = {{Driben, R and Ma, Xuekai and Schumacher, Stefan and Meier, Torsten}}, issn = {{0146-9592}}, journal = {{Optics Letters}}, number = {{6}}, pages = {{1327--1330}}, title = {{{Bloch oscillations of multidimensional dark soliton wave packets and light bullets}}}, doi = {{10.1364/ol.44.001327}}, volume = {{44}}, year = {{2019}}, } @article{15851, author = {{Ma, Xuekai and Kartashov, Yaroslav Y and Gao, Tingge and Schumacher, Stefan}}, issn = {{1367-2630}}, journal = {{New Journal of Physics}}, title = {{{Controllable high-speed polariton waves in a PT-symmetric lattice}}}, doi = {{10.1088/1367-2630/ab5a9b}}, volume = {{21}}, year = {{2019}}, } @unpublished{13340, abstract = {{Spontaneous formation of transverse patterns is ubiquitous in nonlinear dynamical systems of all kinds. An aspect of particular interest is the active control of such patterns. In nonlinear optical systems this can be used for all-optical switching with transistor-like performance, for example realized with polaritons in a planar quantum-well semiconductor microcavity. Here we focus on a specific configuration which takes advantage of the intricate polarization dependencies in the interacting optically driven polariton system. Besides detailed numerical simulations of the coupled light-field exciton dynamics, in the present paper we focus on the derivation of a simplified population competition model giving detailed insight into the underlying mechanisms from a nonlinear dynamical systems perspective. We show that such a model takes the form of a generalized Lotka-Volterra system for two competing populations explicitly including a source term that enables external control. We present a comprehensive analysis both of the existence and stability of stationary states in the parameter space spanned by spatial anisotropy and external control strength. We also construct phase boundaries in non-trivial regions and characterize emerging bifurcations. The population competition model reproduces all key features of the switching observed in full numerical simulations of the rather complex semiconductor system and at the same time is simple enough for a fully analytical understanding of the system dynamics.}}, author = {{Pukrop, Matthias and Schumacher, Stefan}}, booktitle = {{arXiv:1903.12534}}, title = {{{Externally Controlled Lotka-Volterra Dynamics in a Linearly Polarized Polariton Fluid}}}, year = {{2019}}, } @unpublished{13347, abstract = {{<div> <div> <div> <p>Molecular doping in conjugated polymers is a crucial process for their application in organic photovoltaics and optoelectronics. In the present work we theoretically investigate p-type molecu- lar doping in a series of (poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b”]dithiophene)-alt- 4,7-(2,1,3-benzothiadiazole)] (PCPDT-BT) conjugated oligomers with different lengths and three widely-used dopants with different electron affinities, namely F4TCNQ, F6TCNNQ, and CN6-CP. We study in detail the molecular geometry of possible oligomer-dopant complexes and its influence on the doping mechanisms and electronic system properties. We find that the mechanisms of dop- ing and charge transfer observed sensitively depend on the specific geometry of the oligomer-dopant complexes. For a given complex different geometries may exist, some of which show transfer of an entire electron from the oligomer chain onto the dopant molecule resulting in an integer-charge transfer complex, leaving the system in a ground state with broken spin symmetry. In other ge- ometries merely hybridization of oligomer and dopant frontier orbitals occurs with partial charge transfer but spin-symmetric ground state. Considering the resulting electronic density of states both cases may well contribute to an increased electrical conductivity of corresponding film samples while the underlying physical mechanisms are entirely different. </p> </div> </div> </div>}}, author = {{Dong, Chuan-Ding and Schumacher, Stefan}}, title = {{{Molecular Doping of PCPDT-BT Copolymers: Comparison of Molecular Complexes with and Without Integer Charge Transfer}}}, year = {{2019}}, } @article{13343, author = {{Vollbrecht, Joachim and Wiebeler, Christian and Bock, Harald and Schumacher, Stefan and Kitzerow, Heinz-Siegfried}}, issn = {{1932-7447}}, journal = {{The Journal of Physical Chemistry C}}, number = {{7}}, pages = {{4483--4492}}, title = {{{Curved Polar Dibenzocoronene Esters and Imides versus Their Planar Centrosymmetric Homologs: Photophysical and Optoelectronic Analysis}}}, doi = {{10.1021/acs.jpcc.8b10730}}, volume = {{123}}, year = {{2019}}, } @article{50496, abstract = {{Trotz hoher Aktualität und steigender Bedeutung liegen zum Thema Digitalisierung im Sportverein bisher kaum empirische Erkenntnisse vor. Der vorliegende Beitrag setzt sich mit folgenden Fragestellungen auseinander: (i) In welchem Umfang und zu welchem Zweck nutzen Sportvereine digitale Instrumente? (ii) Welche vereinsspezifischen Faktoren determinieren das jeweilige Nutzungsverhalten? Hierzu wurde eine Stichprobe von n=787 Sportvereinen aus Österreich und Deutschland generiert. Es zeigt sich, dass digitale Instrumente vor allem zur internen und externen Kommunikation sowie zur Bewältigung klassischer Verwaltungsaufgaben eingesetzt werden. Das Ausmaß der Nutzung hängt einerseits von vereinsexternen Bedingungen ab. So zeigt sich dahingehend ein Ländereffekt, dass in Deutschland digitale Instrumente stärker genutzt werden als in Österreich. Darüber hinaus haben Auflagen seitens der Verbände zur Verwendung bestimmter Software (z.B. für die Meldung von Wettkampfergebnissen) einen wichtigen Einfluss. Andererseits bestimmen vereinsinterne Faktoren wesentlich das Nutzungsverhalten. Positiv wirken vor allem die Vereinsziele ‚Engagement/Erfolg im Leistungssport‘ und ‚Wollen Vorreiterrolle bei der Digitalisierung einnehmen‘. Negativ wirken eine fehlende Strategie im Umgang mit digitalen Instrumenten sowie die Einschätzung, dass digitale Prozesse nicht zur eigenen Vereinskultur passen. }}, author = {{Riedl, Lars and Ehnold, Peter and Schlesinger, Torsten }}, issn = {{1869-8247}}, journal = {{Sciamus - Sport und Management}}, number = {{4}}, pages = {{21--40}}, title = {{{Digitalisierung im organisierten Sport. Eine Analyse zur Nutzung digitaler Instrumente in Sportvereinen}}}, doi = {{10.24403/jp.1016426}}, year = {{2019}}, } @inproceedings{23764, author = {{Kehne, Franziska and Fechner, Sabine}}, booktitle = {{Naturwissenschaftliche Bildung als Grundlage für berufliche und gesellschaftliche Teilhabe. Gesellschaft für Didaktik der Chemie und Physik, Jahrestagung in Kiel 2018}}, editor = {{Maurer, Christian }}, pages = {{755--758}}, publisher = {{Universität Regensburg}}, title = {{{Enkodierung chemischer Konzepte aus lebenweltlichen Kontexten}}}, year = {{2019}}, } @phdthesis{62824, author = {{Kehne, Franziska}}, publisher = {{Logos Verlag}}, title = {{{Analyse des Transfers von kontextualisiert erworbenem Wissen im Fach Chemie}}}, year = {{2019}}, } @article{59500, author = {{Güsken, Nicholas Alexander and Rieger, Torsten and Mussler, Gregor and Lepsa, Mihail Ion and Grützmacher, Detlev}}, issn = {{1931-7573}}, journal = {{Nanoscale Research Letters}}, number = {{1}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Influence of Te-Doping on Catalyst-Free VS InAs Nanowires}}}, doi = {{10.1186/s11671-019-3004-0}}, volume = {{14}}, year = {{2019}}, } @article{40384, author = {{Ferreri, Alessandro and Ansari, V. and Silberhorn, Christine and Sharapova, Polina R.}}, issn = {{2469-9926}}, journal = {{Physical Review A}}, number = {{5}}, publisher = {{American Physical Society (APS)}}, title = {{{Temporally multimode four-photon Hong-Ou-Mandel interference}}}, doi = {{10.1103/physreva.100.053829}}, volume = {{100}}, year = {{2019}}, } @article{63177, author = {{Ludwig, M and Jablonski, S}}, issn = {{978-84-9048-661-0}}, title = {{{Doing Math Modelling Outdoors-A Special Math Class Activity designed with MathCityMap}}}, year = {{2019}}, } @inproceedings{63197, author = {{Decker, Claudia and Mochalova, Maria}}, location = {{Universität Osnabrück}}, title = {{{Professionalisierung im Lehramtsstudium an der Universität Paderborn}}}, year = {{2019}}, } @article{63325, abstract = {{Abstract We consider the spatially 2D version of the model $$\begin{equation*} \qquad\quad\left\{ \begin{array}{@{}rcll} n_t + u\cdot\nabla n &=& \Delta n - \nabla \cdot \big(nS(x,n,c) \cdot \nabla c \big), \qquad &\qquad x\in \Omega, \ t&gt;0, \\ c_t + u\cdot \nabla c &=& \Delta c - n f(c), \qquad &\qquad x\in \Omega, \ t&gt;0, \\ u_t &=& \Delta u + \nabla P + n\nabla\phi, \qquad \nabla\cdot u=0, \qquad &\qquad x\in \Omega, \ t&gt;0, \end{array} \right. \qquad \qquad (\star) \end{equation*}$$for nutrient taxis processes, possibly interacting with liquid environments. Here the particular focus is on the situation when the chemotactic sensitivity $S$ is not a scalar function but rather attains general values in ${\mathbb{R}}^{2\times 2}$, thus accounting for rotational flux components in accordance with experimental findings and recent modeling approaches. Reflecting significant new challenges that mainly stem from apparent loss of energy-like structures, especially for initial data with large size, the knowledge on ($\star$) so far seems essentially restricted to results on global existence of certain generalized solutions with possibly quite poor boundedness and regularity properties; widely unaddressed seem aspects related to possible effects of such non-diagonal taxis mechanisms on the qualitative solution behavior, especially with regard to the fundamental question whether spatial structures may thereby be supported. The present work answers the latter in the negative in the following sense: under the assumptions that the initial data $(n_0,c_0,u_0)$ and the parameter functions $S$, $f$, and $\phi$ are sufficiently smooth, and that $S$ is bounded and $f$ is positive on $(0,\infty )$ with $f(0)=0$, it is shown that any nontrivial of these solutions eventually becomes smooth and satisfies $$\begin{equation*} n(\cdot,t)\to - \int_\Omega n_0, \quad c(\cdot,t)\to 0 \quad \text{and} \quad u(\cdot,t)\to 0 \qquad \text{as} \ t\to\infty, \end{equation*}$$uniformly with respect to $x\in \Omega$. By not requiring any smallness condition on the initial data, the latter seems new even in the corresponding fluid-free version obtained on letting $u\equiv 0$ in ($\star$).}}, author = {{Winkler, Michael}}, issn = {{1073-7928}}, journal = {{International Mathematics Research Notices}}, number = {{11}}, pages = {{8106--8152}}, publisher = {{Oxford University Press (OUP)}}, title = {{{Can Rotational Fluxes Impede the Tendency Toward Spatial Homogeneity in Nutrient Taxis(-Stokes) Systems?}}}, doi = {{10.1093/imrn/rnz056}}, volume = {{2021}}, year = {{2019}}, } @article{63337, abstract = {{AbstractIn boundedn-dimensional domainsΩ, the Neumann problem for the parabolic equation$$\begin{array}{} \displaystyle u_t = \nabla \cdot \Big( A(x,t)\cdot\nabla u\Big) + \nabla \cdot \Big(b(x,t)u\Big) - f(x,t,u)+g(x,t) \end{array}$$(*)is considered for sufficiently regular matrix-valuedA, vector-valuedband real valuedg, and withfrepresenting superlinear absorption in generalizing the prototypical choice given byf(⋅, ⋅,s) =sαwithα> 1. Problems of this form arise in a natural manner as sub-problems in several applications such as cross-diffusion systems either of Keller-Segel or of Shigesada-Kawasaki-Teramoto type in mathematical biology, and accordingly a natural space for initial data appears to beL1(Ω).The main objective thus consists in examining how far solutions can be constructed for initial data merely assumed to be integrable, with major challenges potentially resulting from the interplay between nonlinear degradation on the one hand, and the possibly destabilizing drift-type action on the other in such contexts. Especially, the applicability of well-established methods such as techniques relying on entropy-like structures available in some particular cases, for instance, seems quite limited in the present setting, as these typically rely on higher initial regularity properties.The first of the main results shows that in the general framework of (*), nevertheless certain global very weak solutions can be constructed through a limit process involving smooth solutions to approximate variants thereof, provided that the ingredients of the latter satisfy appropriate assumptions with regard to their stabilization behavior.The second and seemingly most substantial part of the paper develops a method by which it can be shown, under suitably stregthened hypotheses on the integrability ofband the degradation parameterα, that the solutions obtained above in fact form genuine weak solutions in a naturally defined sense. This is achieved by properly exploiting a weak integral inequality, as satisfied by the very weak solution at hand, through a testing procedure that appears to be novel and of potentially independent interest.To underline the strength of this approach, both these general results are thereafter applied to two specific cross-diffusion systems. Inter alia, this leads to a statement on global solvability in a logistic Keller-Segel system under the assumptionα>$\begin{array}{} \frac{2n+4}{n+4} \end{array}$on the respective degradation rate which seems substantially milder than any previously found condition in the literature. Apart from that, for a Shigesada-Kawasaki-Teramoto system some apparently first results on global solvability forL1initial data are derived.}}, author = {{Winkler, Michael}}, issn = {{2191-950X}}, journal = {{Advances in Nonlinear Analysis}}, number = {{1}}, pages = {{526--566}}, publisher = {{Walter de Gruyter GmbH}}, title = {{{The role of superlinear damping in the construction of solutions to drift-diffusion problems with initial data in L1}}}, doi = {{10.1515/anona-2020-0013}}, volume = {{9}}, year = {{2019}}, }