Results 81 to 90 of about 31,573 (274)

Interlacing - extremal graphs

, 2013
A graph G is singular if the zero-one adjacency matrix has the eigenvalue zero. The multiplicity of the eigenvalue zero is called the nullity of G. For two vertices y and z of G, we call (G, y, z) a device with respect to y and z. The nullities of G, G − y,  G − z and G − y − z classify devices into different kinds.
Borg, Martha, Debono, Mark, Fowler, Patrick W., Pickup, Barry T., Sciriha, Irene   +4 more
openaire   +2 more sources

Extremal problems concerning Kneser graphs

Journal of Combinatorial Theory, Series B, 1986
Let A and B be two intersecting families of k-subsets of an n-element set. It is proved that \(| A\cup B| \leq \left( \begin{matrix} n-1\\ k- 1\end{matrix} \right)+\left( \begin{matrix} n-2\\ k-1\end{matrix} \right)\) holds for \(n>(3+\sqrt{5})k.\) Equality holds only if there exist two elements a,b such that \(\{a,b\}\cap F\neq \emptyset\) for all \(F\
Frankl, P, Füredi, Z
openaire   +2 more sources

Bio‐Orthogonally Crosslinked Supramolecular Polymer Bottlebrush Hydrogels for Long‐Term 3D Cell Culture

Advanced Functional Materials, EarlyView.
Fibrous benzenetrispeptide (BTP) hydrogels, fabricated via strain‐promoted azide‐alkyne cycloaddition (SPAAC) crosslinking, form robust, bioinert networks. These hydrogels can support 3D cell culture, where cell viability and colony growth depend on the fiber content.
Ceren C. Pihlamagi, David Pretzel, Peer Nölte, Kourosh Rezaei, Ulrich S. Schubert, Johannes C. Brendel   +5 more
wiley   +1 more source

On Subtrees of Fan Graphs, Wheel Graphs, and “Partitions” of Wheel Graphs under Dynamic Evolution

Mathematics, 2019
The number of subtrees, or simply the subtree number, is one of the most studied counting-based graph invariants that has applications in many interdisciplinary fields such as phylogenetic reconstruction.
Yu Yang, An Wang, Hua Wang, Wei-Ting Zhao, Dao-Qiang Sun   +4 more
doaj   +1 more source

Infrared Nanocrystals for Space Application: Hardness to Irradiations

Advanced Functional Materials, EarlyView.
This article investigates infrared HgTe nanocrystals under X‐ray and ion irradiation, revealing remarkable radiation hardness. It uncovers distinct degradation mechanisms and shows that the nanomaterial outperforms integrated electronics. The results position colloidal nanocrystals as promising candidates for resilient space and harsh‐environment ...
Alexandre Neyret, Dario Mastrippolito, Bingbing Xia, Adrien Khalili, Maxime Lebreton, Giorgia Strobbia, Albin Colle, Marco Paye, Mariarosa Cavallo, Erwan Bossavit, Claire Abadie, Yoann Prado, Debora Pierucci, Victor Parahyba, Francois Coursaget, David Darson, Emrick Briand, Ian Vickridge, Stephane Demiguel, Sebastien Massenot, Jean‐Marc Belloir, Vincent Goiffon, Emmanuel Lhuillier   +22 more
wiley   +1 more source

Through Diamond Robust Surface Enhanced Raman Spectroscopy

Advanced Functional Materials, EarlyView.
Thin film diamond growth offers a unique opportunity for Surface Enhanced Raman Spectroscopy (SERS); the encapsulation of plasmonic nanostructures within a transparent, chemically stable, and physically robust coating. The diamond acts as both a window and protective layer, enabling illumination of the plasmonic nanostructures through the diamond ...
Kieran N. Twaddle, Rebecca J. Watkins, Ralph J. Moors, Massimiliano L.A. Ramsay, Richard B. Jackman   +4 more
wiley   +1 more source

Copper‐Based Crystalline‐Metallic Glass Composite Thin Films: A Novel Material with Enhanced Strength and Thermally Stable Nanotwins

Advanced Functional Materials, EarlyView.
A Cu‐based crystal‐glass composite with high‐density twins is identified by a fast screening technique using combinatorial sputtering together with XRD and nanoindentation mapping. This bamboo‐like structure demonstrates homogenous plastic flow and retains high strength during in situ high temperature tests, up to 1 GPa at 550°C, owing to those ...
Chunhua Tian, Amit Sharma, Krzysztof Wieczerzak, Alexander Groetsch, Manish Jain, Nicolò Maria della Ventura, Remo Widmer, Fedor F. Klimashin, Johann Michler, Jakob Schwiedrzik, Xavier Maeder   +10 more
wiley   +1 more source

Commuting graphs and extremal centralizers

Ars Mathematica Contemporanea, 2013
We determine the conditions for matrix centralizers which can guarantee the connectedness of the commuting graph for the full matrix algebra M n ( F ) over an arbitrary field F . It is known that if F is an algebraically closed field and n  ≥ 3 , then the diameter of the commuting graph of M n ( F ) is always equal to four.
Dolinar, Gregor, Guterman, Aleksandr Emilevič, Kuzma, Bojan, Oblak, Polona   +3 more
openaire   +4 more sources

The Cuttlebone Blueprint for Multifunctional Metamaterials: Design Taxonomy, Functional Decoupling, and Future Horizons

Advanced Functional Materials, EarlyView.
Cuttlebone‐inspired metamaterials exploit a septum‐wall architecture to achieve excellent mechanical and functional properties. This review classifies existing designs into direct biomimetic, honeycomb‐type, and strut‐type architectures, summarizes governing design principles, and presents a decoupled design framework for interpreting multiphysical ...
Xinwei Li, Zhendong Li
wiley   +1 more source

Extremal K (s,t)-free bipartite graphs

Discrete Mathematics & Theoretical Computer Science, 2008
In this paper new exact values of the Zarankiewicz function z(m,n;s,t) are obtained assuming certain requirements on the parameters. Moreover, all the corresponding extremal graphs are characterized.
C. Balbuena, P. Garcia-Vazquez, X. Marcote, J.C. Valenzuela   +3 more
doaj