Results 71 to 80 of about 8,753,370 (220)

The packing chromatic number of the square lattice is at least 12

open access: yesCoRR, 2010
The packing chromatic number $χ_ρ(G)$ of a graph $G$ is the smallest integer $k$ such that the vertex set $V(G)$ can be partitioned into disjoint classes $X_1, ..., X_k$, where vertices in $X_i$ have pairwise distance greater than $i$. For the 2-dimensional square lattice $\mathbb{Z}^2$ it is proved that $χ_ρ(\mathbb{Z}^2) \geq 12$, which improves the ...
Jan Ekstein   +3 more
openaire   +2 more sources

Global distribution of avian plumage coloration and patterning: the relative influence of climate, ecology, and sexual selection

open access: yesEcography, EarlyView.
Animal coloration exhibits substantial biogeographic variation, reflecting complex adaptations to both abiotic and biotic environments. Although the evolutionary mechanisms underlying avian plumage coloration have been widely studied, geographic variation in plumage patterning has received far less attention.
Yuqing Han   +8 more
wiley   +1 more source

Dual‐Mode Electrophoretic Displays Enabled by Quantum Dot‐Decorated PR48:2 Pigment Particles and TiO2 for All‐Weather Visibility, Excellent Bistability, and Enhanced Readability

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
This study presents a novel quantum dot electrophoretic display (QDEPD), which combines electro‐controlled reflection and optically‐triggered emission to achieve efficient multi‐modal switching within a single pixel. By incorporating multi‐component nanostructures, the system enhances functional integration and multi‐modal response capabilities.
Xingke Zheng   +8 more
wiley   +1 more source

High‐Strength, Fluorescent, Triboelectric Cellulose Hydrogel‐Derived Plastics Through Molecular Network Engineering for Energy Harvesting and Motion Sensing

open access: yesENERGY &ENVIRONMENTAL MATERIALS, EarlyView.
Multifunctional cellulose hydrogel‐derived plastics (FCBPs) are fabricated via a novel molecular network engineering strategy involving epoxy cross‐linking, solvent exchange, and hot‐pressing techniques. The resulting materials exhibit high mechanical strength, excellent thermal/solvent resistance, stable fluorescence, complete biodegradability, and ...
Fuyuan Lu   +11 more
wiley   +1 more source

The Packing Chromatic Number of Random d-regular Graphs [PDF]

open access: yes, 2015
Let G = (V (G),E(G)) be a simple graph of order n and let i be a positive integer. Xi superset V (G) is called an i-packing if vertices in Xi are pairwise distance more than i apart. A packing coloring of G is a partition X = {X1,X2,X3, . . .
Clifton, Ann Wells
core   +1 more source

On the Packing Chromatic Number of Trees, Cartesian Products and Some Infinite Graphs

open access: yesElectronic Notes in Discrete Mathematics, 2008
Abstract A subset A of vertices in a graph G is an r-packing if the distance between every pair of distinct vertices in A is more than r. The packing chromatic number, χ ρ ( G ) , is the smallest k for which there exists some partition V 1 , V 2 , … , V k of the vertex set of G such that V r is an r-packing ...
Douglas F. Rall   +3 more
openaire   +1 more source

Packing Chromatic Number of Coronae of Paths and Cycles [PDF]

open access: yes, 2019
Pakirno kromatično število $chi_{pi}(G)$ grafa $G$ je najmanjši $k$, za katerega lahko poiščemo $k$-pakirno barvanje grafa, torej najmanjši $k$, za katerega obstaja taka funkcija $pi: (G) to [k]$, da iz $pi(u) = pi(v)$ sledi, da je razdalja med $u$ in $v$
Robba, Barbara
core  

Regioselective Oxidative Oligomerization of 2‐Tert‐Butylpyrene Toward Structurally Defined Oligomers and Their Application in Organic Light‐Emitting Diodes

open access: yesEuropean Journal of Organic Chemistry, EarlyView.
Treatment of 2‐tert‐butylpyrene with Cu2+ afforded structurally well‐defined pyrene oligomers, up to the 13‐mer. Single‐crystal X‐ray diffraction, spectroscopic analyses, and computational studies were conducted to evaluate the properties of the resulting oligopyrenes.
Md Jadu Mia   +14 more
wiley   +1 more source

Chromatic roots are dense in the whole complex plane [PDF]

open access: yes, 2004
I show that the zeros of the chromatic polynomials P-G(q) for the generalized theta graphs Theta((s.p)) are taken together, dense in the whole complex plane with the possible exception of the disc \q - l\ < l.
Sokal, AD
core  

A High‐Efficiency Yet Sustainable Fresh‐Keeping Strategy Inspired by Calyx of Physalis peruviana

open access: yesExploration, EarlyView.
This study presents a sprayable, calyx‐inspired food wrap engineered for safety and sustainability using handheld electrospraying. The wrap forms a health‐critical protective barrier with high antiviral and antibacterial efficacy, excellent breathability, and long‐term fresh‐keeping performance.
Yue Zhao   +17 more
wiley   +1 more source

Home - About - Disclaimer - Privacy