Results 101 to 110 of about 614,238 (277)

An analogue of the Milnor conjecture for the de Rham-Witt complex in characteristic 2

Forum of Mathematics, Sigma
We describe the modulo $2$ de Rham-Witt complex of a field of characteristic $2$ , in terms of the powers of the augmentation ideal of the $\mathbb {Z}/2$ -geometric fixed points of real topological restriction homology ${\mathrm ...
Emanuele Dotto
doaj   +1 more source

Survey on geometric group theory

, 2008
This article is a survey article on geometric group theory from the point of view of a non-expert who likes geometric group theory and uses it in his own research. The sections are: classical examples, basics about quasiisometry,properties and invariants of groups invariant under quasiisometry, rigidity, hyperbolic spaces and CAT(k)-spaces, the ...
openaire   +2 more sources

Exploring Dipolar Dynamics and Ionic Transport in Metal‐Organic Frameworks: Experimental and Theoretical Insights

Advanced Functional Materials, EarlyView.
In this study, the interplay of dipolar dynamics and ionic charge transport in MOF compounds is investigated. Synthesizing the novel structure CFA‐25 with integrated freely rotating dipolar groups, local and macroscopic effects, including interactions with Cs cations are explored.
Ralph Freund, Arthur Schulz, Peter Lunkenheimer, Maryana Kraft, Thomas Bergler, Harald Oberhofer, Dirk Volkmer   +6 more
wiley   +1 more source

An Inverse Problem in Number Theory and Geometric Group Theory [PDF]

, 2010
This paper describes a new link between combinatorial number theory and geometry. The main result states that A is a finite set of relatively prime positive integers if and only if A = (K-K) \cap N, where K is a compact set of real numbers such that for every real number x there exists y in K with x \equiv y mod 1.
openaire   +2 more sources

Analyzing Electronic Excitations and Exciton Binding Energies in Y6 Films

Advanced Functional Materials, EarlyView.
The Y6 molecule is used for increasing the efficiency of organic solar cells. The exciton binding energy is calculated for ensembles of Y6 molecules that are representative of the typically used films. The calculations show that the excitons typically spread out over many molecules.
Sahar Javaid Akram, Sophie Meißner, Stephan Kümmel   +2 more
wiley   +1 more source

Enhancing Optoelectronic Properties in Phthalocyanine‐Based SURMOFs: Synthesis of ABAB Linkers by Avoiding Statistical Condensation with Tailored Building Blocks

Advanced Functional Materials, EarlyView.
A novel phthalocyanine (PC)‐based metal–organic framework (MOFs) is synthesized using ditopic PC linkers obtained through regioselective statistical condensation. The resulting MOF exhibits significant improvements in electronic absorption, thereby enhancing the material's performance in light harvesting and energy conversion.
Lukas S. Langer, Mareen Stahlberger, Xiaojing Liu, Yi Luo, Niklas E. Häußermann, Puja Singhvi, Yidong Liu, Olaf Fuhr, Martin Nieger, Lars Heinke, Thomas Heine, Christof Wöll, Stefan Bräse   +12 more
wiley   +1 more source

Photoswitchable Conductive Metal–Organic Frameworks

Advanced Functional Materials, EarlyView.
A conductive material where the conductivity can be modulated remotely by irradiation with light is presented. It is based on films of conductive metal–organic framework type Cu3(HHTP)2 with embedded photochromic molecules such as azobenzene, diarylethene, spiropyran, and hexaarylbiimidazole in the pores.
Yidong Liu, Mersad Mostaghimi, Abhinav Chandresh, Saibal Jana, Wolfgang Wenzel, Lars Heinke   +5 more
wiley   +1 more source

Intermolecular Interactions as Driving Force of Increasing Multiphoton Absorption in a Perylene Diimide‐Based Coordination Polymer

Advanced Functional Materials, EarlyView.
This study uncovers the unexplored role of intermolecular interactions in multiphoton absorption in coordination polymers. By analyzing [Zn2tpda(DMA)2(DMF)0.3], it shows how the electronic coupling of the chromophores and confinement in the MOF enhance two‐and three‐photon absorption.
Simon Nicolas Deger, Anna Mauri, Yang Cui, Sebastian Josef Weishäupl, Ali Deniz Özdemir, Hamad Syed, Aleksandr Ovsianikov, Wolfgang Wenzel, Alexander Pöthig, Jürgen Hauer, Mariana Kozlowska, Roland Augustinus Fischer   +11 more
wiley   +1 more source

Understanding and Optimizing Li Substitution in P2‐Type Sodium Layered Oxides for Sodium‐Ion Batteries

Advanced Functional Materials, EarlyView.
This work explores Li‐substituted P2 layered oxides for Na‐ion batteries by crystallographic and electrochemical studies. The effect of lithium on superstructure orderings, on phase transitions during synthesis and electrochemical cycling and on the interplay of O‐ versus TM‐redox is revealed via various advanced techniques, including semi‐simultaneous 
Mingfeng Xu, Giovanni Gammaitoni, Michael Häfner, Eduardo Villalobos‐Portillo, Carlo Marini, Matteo Bianchini   +5 more
wiley   +1 more source

Duality and infinite distance limits in asymmetric freely acting orbifolds

Journal of High Energy Physics
We use freely acting asymmetric orbifolds of type IIB string theory to construct a class of theories in four dimensions with eight supercharges. Their low energy effective field theories resemble STU models, but have different duality groups: the ...
George Gkountoumis, Chris Hull, Guo-En Nian, Stefan Vandoren   +3 more
doaj   +1 more source