@article{53345, abstract = {{AbstractA no-flux initial-boundary value problem for

ut=Δ(uϕ(v)),vt=Δv−uv,(⋆)is considered in smoothly bounded subdomains of

with

n⩾1

and suitably regular initial data, whereφis assumed to reflect algebraic type cross-degeneracies by sharing essential features with

0⩽ξ↦ξα

for some

α⩾1

. Based on the discovery of a gradient structure acting at regularity levels mild enough to be consistent with degeneracy-driven limitations of smoothness information, in this general setting it is shown that with some measurable limit profile

u∞

and some null set

N⋆⊂(0,∞)

, a corresponding global generalized solution, known to exist according to recent literature, satisfies

ρ(u(⋅,t))⇀⋆ρ(u∞)in L∞(Ω) and v(⋅,t)→0in Lp(Ω)for all p⩾1as

(0,∞)∖N⋆∋t→∞

, where

ρ(ξ):=ξ2(ξ+1)2

ξ⩾0

. In the particular case when either

n⩽2

and

α⩾1

is arbitrary, or

n⩾1

and

α∈[1,2]

, additional quantitative information on the deviation of trajectories from the initial data is derived. This is found to imply a lower estimate for the spatial oscillation of the respective first components throughout evolution, and moreover this is seen to entail that each of the uncountably many steady states

(u⋆,0)

of (

⋆

) is stable with respect to a suitably chosen norm topology.}}, author = {{Winkler, Michael}}, issn = {{0951-7715}}, journal = {{Nonlinearity}}, keywords = {{Applied Mathematics, General Physics and Astronomy, Mathematical Physics, Statistical and Nonlinear Physics}}, number = {{8}}, pages = {{4438--4469}}, publisher = {{IOP Publishing}}, title = {{{Stabilization despite pervasive strong cross-degeneracies in a nonlinear diffusion model for migration–consumption interaction}}}, doi = {{10.1088/1361-6544/ace22e}}, volume = {{36}}, year = {{2023}}, } @article{53341, abstract = {{AbstractThe Cauchy problem in

$$\mathbb {R}^n$$

R n is considered for the Keller–Segel system

$$\begin{aligned} \left\{ \begin{array}{l}u_t = \Delta u - \nabla \cdot (u\nabla v), \\ 0 = \Delta v + u, \end{array} \right. \qquad \qquad (\star ) \end{aligned}$$

u t = Δ u - ∇ · ( u ∇ v ) , 0 = Δ v + u , ( ⋆ ) with a focus on a detailed description of behavior in the presence of nonnegative radially symmetric initial data

$$u_0$$

u 0 with non-integrable behavior at spatial infinity. It is shown that if

$$u_0$$

u 0 is continuous and bounded, then (

$$\star $$

⋆ ) admits a local-in-time classical solution, whereas if

$$u_0(x)\rightarrow +\infty $$

u 0 ( x ) → + ∞ as

$$|x|\rightarrow \infty $$

| x | → ∞ , then no such solution can be found. Furthermore, a collection of three sufficient criteria for either global existence or global nonexistence indicates that with respect to the occurrence of finite-time blow-up, spatial decay properties of an explicit singular steady state plays a critical role. In particular, this underlines that explosions in (

$$\star $$

⋆ ) need not be enforced by initially high concentrations near finite points, but can be exclusively due to large tails.}}, author = {{Winkler, Michael}}, issn = {{2296-9020}}, journal = {{Journal of Elliptic and Parabolic Equations}}, keywords = {{Applied Mathematics, Numerical Analysis, Analysis}}, number = {{2}}, pages = {{919--959}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Solutions to the Keller–Segel system with non-integrable behavior at spatial infinity}}}, doi = {{10.1007/s41808-023-00230-y}}, volume = {{9}}, year = {{2023}}, } @article{53339, abstract = {{The chemotaxis‐Stokes system is considered along with homogeneous boundary conditions of no‐flux type for and , and of Dirichlet type for , in a smoothly bounded domain . Under the assumption that , that is bounded on each of the intervals with arbitrary , and that with some and , we have It is shown that for any suitably regular initial data, an associated initial‐boundary value problem admits a global very weak solution.}}, author = {{Tian, Yu and Winkler, Michael}}, issn = {{0170-4214}}, journal = {{Mathematical Methods in the Applied Sciences}}, keywords = {{General Engineering, General Mathematics}}, number = {{14}}, pages = {{15667--15683}}, publisher = {{Wiley}}, title = {{{Keller–Segel–Stokes interaction involving signal‐dependent motilities}}}, doi = {{10.1002/mma.9419}}, volume = {{46}}, year = {{2023}}, } @article{53340, author = {{Painter, Kevin J. and Winkler, Michael}}, issn = {{0036-1399}}, journal = {{SIAM Journal on Applied Mathematics}}, keywords = {{Applied Mathematics}}, number = {{5}}, pages = {{2096--2117}}, publisher = {{Society for Industrial & Applied Mathematics (SIAM)}}, title = {{{Phenotype Switching in Chemotaxis Aggregation Models Controls the Spontaneous Emergence of Large Densities}}}, doi = {{10.1137/22m1539393}}, volume = {{83}}, year = {{2023}}, } @article{53342, author = {{Winkler, Michael and Yokota, Tomomi}}, issn = {{0022-0396}}, journal = {{Journal of Differential Equations}}, keywords = {{Analysis, Applied Mathematics}}, pages = {{1--28}}, publisher = {{Elsevier BV}}, title = {{{Avoiding critical mass phenomena by arbitrarily mild saturation of cross-diffusive fluxes in two-dimensional Keller-Segel-Navier-Stokes systems}}}, doi = {{10.1016/j.jde.2023.07.029}}, volume = {{374}}, year = {{2023}}, } @article{53346, author = {{Winkler, Michael}}, issn = {{1079-9389}}, journal = {{Advances in Differential Equations}}, keywords = {{Applied Mathematics, Analysis}}, number = {{11/12}}, publisher = {{Khayyam Publishing, Inc}}, title = {{{Absence of collapse into persistent Dirac-type singularities in a Keller-Segel-Navier-Stokes system involving local sensing}}}, doi = {{10.57262/ade028-1112-921}}, volume = {{28}}, year = {{2023}}, } @article{45984, author = {{Kaur, Mannat and Sri Ramulu, Harshini and Acar, Yasemin and Fiebig, Tobias}}, journal = {{Proc. ACM Hum. Comput. Interact.}}, number = {{CSCW1}}, pages = {{1–38}}, title = {{{"Oh yes! over-preparing for meetings is my jam :)": The Gendered Experiences of System Administrators}}}, doi = {{10.1145/3579617}}, volume = {{7}}, year = {{2023}}, } @book{51101, author = {{Werth, Gerda}}, isbn = {{9783658424442}}, issn = {{2661-8591}}, publisher = {{Springer Fachmedien Wiesbaden}}, title = {{{Neue Wege im mathematischen Unterricht: Auf den Spuren Mathilde Vaertings}}}, doi = {{10.1007/978-3-658-42445-9}}, year = {{2023}}, } @article{51103, author = {{Werth, Gerda}}, journal = {{mathematik lehren}}, pages = {{15--19}}, publisher = {{Friedrich}}, title = {{{Standardkonstruktionen eigenständig entdecken. Mathilde Vaertings Idee der Selbstständigkeitsprobe}}}, volume = {{241}}, year = {{2023}}, } @inproceedings{51739, author = {{Weiß, Deborah and Duffe, Tobias and Buczek, Moritz and Kullmer, Gunter and Schramm, Britta}}, location = {{Berlin}}, publisher = {{Deutscher Verband für Materialforschung und -prüfung e.V.}}, title = {{{Bruchmechanische Untersuchung des Dualphasenstahls HCT590X unter Temperatureinfluss}}}, doi = {{10.48447/WP-2023-244}}, year = {{2023}}, } @inbook{35904, author = {{Böttger, Lydia and Niederhaus, Constanze}}, booktitle = {{Berufs- und Fachsprache Deutsch in Wissenschaft und Praxis. Ein Handbuch aus DaF- und DaZ Perspektive}}, editor = {{Efing, Christian and Kalkavan-Aydin, Zeynep}}, publisher = {{De Gruyter}}, title = {{{CLIL - Content and Language Integrated Learning}}}, doi = {{https://doi.org/10.1515/9783110745504}}, year = {{2023}}, } @unpublished{53404, abstract = {{In this short note we observe, on locally symmetric spaces of higher rank, a connection between the growth indicator function introduced by Quint and the modified critical exponent of the Poincar\'e series equipped with the polyhedral distance. As a consequence, we provide a different characterization of the bottom of the $L^2$-spectrum of the Laplace-Beltrami operator in terms of the growth indicator function. Moreover, we explore the relationship between these three objects and the temperedness.}}, author = {{Wolf, Lasse L. and Zhang, Hong-Wei}}, booktitle = {{arXiv:2311.11770}}, title = {{{$L^2$-spectrum, growth indicator function and critical exponent on locally symmetric spaces}}}, year = {{2023}}, } @inbook{53405, abstract = {{Das Verhältnis zwischen Wissenschaft und Praxis wurde in unterschiedlichen Forschungsansätzen im- mer wieder wissenschaftlich betrachtet. Dennoch ist es notwendig, sich im Rahmen der wissenschafts- theoretischen Konzeption von Design-Based Research (DBR) weiter damit auseinanderzusetzen, denn Interaktion zwischen Wissenschaft und Bildungspraxis ist ein zentrales Merkmal von DBR. Dieser Beitrag befasst sich mit der Frage, wie sich diese Interaktion je nach zugrunde liegendem DBR-Verständnis me- thodologisch fassen lässt. Die Interaktion wird als ein wesentlicher Bestandteil des Erkenntnisprozesses in DBR aufgefasst. Daher wird neben der methodischen Ausgestaltung von Interaktionsprozessen auch methodologisch reflektiert, was die Wissenschaft-Praxis-Interaktion für die Erkenntnis an sich bedeutet.}}, author = {{Jenert, Tobias}}, booktitle = {{Wissenschaft trifft Praxis – Designbasierte Forschung in der beruflichen Bildung}}, editor = {{Kremer, H.-Hugo and Ertl, Hubert and Sloane, Peter F. E.}}, pages = {{11--24}}, publisher = {{Bundesinstitut für Berufsbildung.}}, title = {{{Design-Based Research als Erforschung und Gestaltung von Interaktionsprozessen zwischen Wissenschaft und Bildungspraxis}}}, year = {{2023}}, } @inproceedings{52380, author = {{Sparmann, Sören and Hüsing, Sven and Schulte, Carsten}}, booktitle = {{Proceedings of the 23rd Koli Calling International Conference on Computing Education Research}}, publisher = {{ACM}}, title = {{{JuGaze: A Cell-based Eye Tracking and Logging Tool for Jupyter Notebooks}}}, doi = {{10.1145/3631802.3631824}}, year = {{2023}}, } @article{53410, abstract = {{AbstractWe consider a geodesic billiard system consisting of a complete Riemannian manifold and an obstacle submanifold with boundary at which the trajectories of the geodesic flow experience specular reflections. We show that if the geodesic billiard system is hyperbolic on its trapped set and the latter is compact and non-grazing, the techniques for open hyperbolic systems developed by Dyatlov and Guillarmou (Ann Henri Poincaré 17(11):3089–3146, 2016) can be applied to a smooth model for the discontinuous flow defined by the non-grazing billiard trajectories. This allows us to obtain a meromorphic resolvent for the generator of the billiard flow. As an application we prove a meromorphic continuation of weighted zeta functions together with explicit residue formulae. In particular, our results apply to scattering by convex obstacles in the Euclidean plane.}}, author = {{Delarue, Benjamin and Schütte, Philipp and Weich, Tobias}}, issn = {{1424-0637}}, journal = {{Annales Henri Poincaré}}, keywords = {{Mathematical Physics, Nuclear and High Energy Physics, Statistical and Nonlinear Physics}}, number = {{2}}, pages = {{1607--1656}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Resonances and Weighted Zeta Functions for Obstacle Scattering via Smooth Models}}}, doi = {{10.1007/s00023-023-01379-x}}, volume = {{25}}, year = {{2023}}, } @unpublished{53411, abstract = {{We compute a Riemann-Roch formula for the invariant Riemann-Roch number of a quantizable Hamiltonian $S^1$-manifold $(M,\omega,\mathcal{J})$ in terms of the geometry of its symplectic quotient, allowing $0$ to be a singular value of the moment map $\mathcal{J}:M\to\mathbb{R}$. The formula involves a new explicit local invariant of the singularities. Our approach relies on a complete singular stationary phase expansion of the associated Witten integral.}}, author = {{Delarue, Benjamin and Ioos, Louis and Ramacher, Pablo}}, booktitle = {{arXiv:2302.09894}}, title = {{{A Riemann-Roch formula for singular reductions by circle actions}}}, year = {{2023}}, } @phdthesis{53434, abstract = {{Im Rahmen dieser Dissertation wurden Katalysatoren, welche auf der thermischen Zersetzung von metallorganischen Gerüstverbindungen basieren, mittels Röntgenabsorptionsspektroskopie (XAS) und Röntgenemissionsspektroskopie (XES) untersucht. Durch diesen synthetischen Ansatz können hochdisperse Ni-basierte Katalysatoren eingebettet in einer Kohlenstoffmatrix gewonnen werden, welche für die Methanisierung von CO2 Einsatz finden. Diese sollen eine hohe Stabilität gegenüber Wasserstoffausfällen aufweisen, welche bedingt durch Wetterfluktuationen in der Gewinnung von grünem Wasserstoff auftreten. Um ein derartiges System gezielt gestalten zu können, ist ein detailliertes Verständnis zugrundeliegender chemischer Mechanismen und damit einhergehend elektronischer Strukturen der Katalysatorsysteme notwendig. Durch die detaillierte Analyse der Katalysator-Vorstufen mittels XAS konnte gezeigt werden, dass auch unter reduktiven Bedingungen in der thermischen Zersetzung Spuren von Ni(II) vorliegen und keine reine Nifcc-Struktur erreicht werden konnte. Eine detaillierte Auswertung der gleichen Präkatalysatoren mittels XES konnte durch eine neuartige Kombination von HERFD-XANES, theoretischer Berechnungen und VtC-XES einen eindeutigen Beweis für das Vorhandensein der gewünschten Kohlenstoffmatrix sowie Spuren von NiO im Präkatalysator liefern, welche sich vorteilhaft auf die spätere Aktivität im finalen Katalysator auswirken. Abschließend konnte mittels einer in-situ Untersuchung der Temperaturbereich, in dem sich die aktive Katalysatorspezies ausbildet, auf 80 bis 200 C eingegrenzt werden. Schließlich konnte ein eindeutiger Zusammenhang zwischen dem Verlust einer stabilisierenden Kohlenstoffschicht und einem Rückgang der Aktivität belegt werden.}}, author = {{Strübbe, Sven}}, pages = {{198}}, publisher = {{Universitätsbibliothek Paderborn}}, title = {{{Investigations of Ni-based methanation catalysts under dynamic conditions via hard X-ray spectroscopy}}}, doi = {{10.17619/UNIPB/1-1752}}, year = {{2023}}, } @inbook{50736, author = {{Pieper, Catania and Kottmann, Brigitte and Reh, Anne}}, booktitle = {{Mentoring-Projekt für Roma-Kinder in Europa}}, editor = {{Òhidy, Andrea}}, pages = {{325--356}}, publisher = {{Universität Pécs }}, title = {{{Das Projekt "Schule für Alle" der Universität Bielefeld: ein Mentoring-Projekt mit rassismuskritischen Ansätzen in Deutschland}}}, year = {{2023}}, } @inproceedings{53436, author = {{Stiballe, Alisa and Welzel, Simon and Dorfschmidt, Johannes and Schluter, Darvin and Steuter, Dominik Delgado and Hense, Jannik Lukas and Klingler, Florian}}, booktitle = {{2023 IEEE 48th Conference on Local Computer Networks (LCN)}}, publisher = {{IEEE}}, title = {{{Demo: Chat based Emergency Service via Long Range Wireless Communication (LoRa)}}}, doi = {{10.1109/lcn58197.2023.10223398}}, year = {{2023}}, } @inproceedings{53438, author = {{Franke, Mario and Stroop, Roland and Klingler, Florian and Sommer, Christoph}}, booktitle = {{2023 IEEE 97th Vehicular Technology Conference (VTC2023-Spring)}}, publisher = {{IEEE}}, title = {{{Low Earth Orbit Satellite Supported Multi-Hop Dissemination of Messages in V2X Networks}}}, doi = {{10.1109/vtc2023-spring57618.2023.10200344}}, year = {{2023}}, }