Results 41 to 50 of about 7,617 (257)

Microscopic Insights into Magnetic Warping and Time‐Reversal Symmetry Breaking in Topological Surface States of Rare‐Earth‐Doped Bi2Te3

open access: yesAdvanced Materials, EarlyView.
Magnetic doping of the topological insulator Bi2Te3 with erbium adatoms induces out‐of‐plane magnetism and breaks time‐reversal symmetry, opening a Dirac gap and driving a Fermi surface transition from hexagonal to star‐of‐David geometry. Microscopy, spectroscopy, and magnetic dichroism reveal atomically controlled magnetic interactions that tailor the
Beatriz Muñiz Cano   +18 more
wiley   +1 more source

Catalan Numbers for the Classroom?

open access: yesElemente der Mathematik, 1997
The author describes the experiences with 13-14 years old pupils in a project on Catalan numbers. She asserts that solving simple combinatorial problems plays an important role in developing thought processes, and should be practised throughout secondary school.
openaire   +3 more sources

Chromatic Spectrum of $K_s$-WORM Colorings of $K_n$ [PDF]

open access: yesComputer Science Journal of Moldova, 2020
An {\it $H$-WORM} coloring of a simple graph $G$ is the coloring of the vertices of $G$ such that no copy of $H\subseteq G$ is monochrome or rainbow. In a recently published article by one of the authors \cite{All1}, it was claimed that the number of $r$
Julian A.D. Allagan, Kenneth L. Jones
doaj  

Spin‐Split Edge States in Metal‐Supported Graphene Nanoislands Obtained by CVD

open access: yesAdvanced Materials, EarlyView.
Combining STM measurements and ab‐initio calculations, we show that zig‐zag edges in graphene nanoislands grown on Ni(111) by CVD retrieve their spin‐polarized edge states after intercalation of a few monolayers of Au. ABSTRACT Spin‐split states localized on zigzag edges have been predicted for different free‐standing graphene nanostructures.
Michele Gastaldo   +6 more
wiley   +1 more source

Some combinatorial identities containing central binomial coefficients or Catalan numbers*

open access: yesApplied Mathematics in Science and Engineering, 2023
In the article, by virtue of Maclaurin's expansions of the arcsine function and its square and cubic, the authors give a short proof of a sum formula of a Maclaurin's series with coefficients containing reciprocals of the Catalan numbers; establish four ...
Feng Qi, Da-Wei Niu, Dongkyu Lim
doaj   +1 more source

COFs on MOFs: Layer‐by‐Layer Synthesis of MOF@COF Nanoparticles with Synergistic Adsorption

open access: yesAdvanced Materials, EarlyView.
A layer‐by‐layer strategy enables the growth of crystalline covalent organic framework (COF) shells on metal–organic framework nanoparticles, creating core–shell structures with tunable porosity. Ordered interstitial mesopores are formed during shell growth, which are connected with the COF's intrinsic micropores, thereby enhancing water sorption. This
Ana Guillem‐Navajas   +11 more
wiley   +1 more source

Delannoy numbers and Legendre polytopes [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2008
We construct an $n$-dimensional polytope whose boundary complex is compressed and whose face numbers for any pulling triangulation are the coefficients of the powers of $(x-1)/2$ in the $n$-th Legendre polynomial.
Gábor Hetyei
doaj   +1 more source

Highly Flexible and Conformable ZnO/FeGa Magnetoelectric Heterostructures for Skin wound Healing

open access: yesAdvanced Science, EarlyView.
The magnetic field‐induced electric field generated by a highly flexile ZnO(piezoelectric)/FeGa(magnetostrictive) magnetoelectric heterostructure embedded in the low Young's modulus elastomer PDMS has been used to stimulate the wound healing processes.
Filippos Perdikos   +17 more
wiley   +1 more source

Permutations avoiding an increasing number of length-increasing forbidden subsequences [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2000
A permutation π is said to be τ -avoiding if it does not contain any subsequence having all the same pairwise comparisons as τ . This paper concerns the characterization and enumeration of permutations which avoid a set F^j of subsequences increasing ...
Elena Barcucci   +3 more
doaj   +1 more source

On Some Properties of Bihyperbolic Numbers of The Lucas Type

open access: yesCommunications in Advanced Mathematical Sciences, 2023
To date, many authors in the literature have worked on special arrays in various computational systems. In this article, Lucas type bihyperbolic numbers were defined and their algebraic properties were examined. Bihyperbolic Lucas numbers were studied by
Fügen Torunbalcı Aydın
doaj   +1 more source

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