Results 61 to 70 of about 155,898 (247)

Beyond Percolation: Graphene‐Enabled Network Reinforcement Enhances Thermal Transport in Paraffin Phase‐Change Composites

open access: yesAdvanced Science, EarlyView.
Expanded‐graphite/graphene‐nanoplatelet hybrids deliver a near‐order‐of‐magnitude thermal‐conductivity enhancement in paraffin phase‐change materials. A microCT‐informed 3D modeling framework resolves the percolating EG backbone and captures sub‐voxel GNP enrichment, quantitatively linking microstructure to heat flow and revealing a graphene‐enabled ...
Thomas Hoke   +4 more
wiley   +1 more source

Normal forms and hyperbolic algebraic limit cycles for a class of polynomial differential systems

open access: yesElectronic Journal of Differential Equations, 2018
We study the normal forms of polynomial systems having a set of invariant algebraic curves with singular points. We provide sufficient conditions for the existence of hyperbolic algebraic limit cycles.
Jaume Llibre, Claudia Valls
doaj  

An exciting Approach to Theoretical Spectroscopy

open access: yesAdvanced Science, EarlyView.
ABSTRACT Theoretical spectroscopy, and more generally, electronic‐structure theory, are powerful concepts for describing the complex many‐body interactions in materials. They cover methods from ground‐state properties to lattice excitations and light‐matter interaction, including time‐resolved variants.
Martí Raya‐Moreno   +29 more
wiley   +1 more source

Polynomial differential systems with explicit non-algebraic limit cycles

open access: yesElectronic Journal of Differential Equations, 2012
Up to now all the examples of polynomial differential systems for which non-algebraic limit cycles are known explicitly have degree at most 5. Here we show that already there are polynomial differential systems of degree at least exhibiting explicit ...
Rebiha Benterki, Jaume Llibre
doaj  

Correcting Apparent Priming Bias Unveils Fertilizer Nitrogen‐Risk Archetypes of Surplus and Depletion Across Asian Rice Systems

open access: yesAdvanced Science, EarlyView.
Correcting the apparent priming effect resolves systematic biases in Asian rice fertilizer nitrogen accounting. Net soil retention drops below 7%, while 48% of fertilizer escapes, inflicting US$98.53 billion in annual reactive‐nitrogen damages. High‐resolution mapping uncovers N‐risk archetypes across 42% of the rice area, delivering a spatially ...
Xiuyun Liu   +5 more
wiley   +1 more source

On non-conservative perturbations of three-dimensional integrable systems [PDF]

open access: yesИзвестия высших учебных заведений: Прикладная нелинейная динамика
At present, non-conservative perturbations of two-dimensional nonlinear Hamiltonian systems have been studied quite fully. The purpose of the study is to generalize this theory to the three-dimensional case, when the unperturbed system is nonlinear ...
Morozov, Kirill Евгеньевич
doaj   +1 more source

The 16th Hilbert problem restricted to circular algebraic limit cycles

open access: yes, 2016
We prove the following two results. First every planar polynomial vector field of degree S with S invariant circles is Darboux integrable without limit cycles.
J. Llibre   +3 more
semanticscholar   +1 more source

Algebraic approximations to bifurcation curves of limit cycles for the Liénard equation

open access: yesPhysics Letters A, 1998
In this paper, we study the bifurcation of limit cycles in Lienard systems of the form dot(x)=y-F(x), dot(y)=-x, where F(x) is an odd polynomial that contains, in general, several free parameters. By using a method introduced in a previous paper, we obtain a sequence of algebraic approximations to the bifurcation sets, in the parameter space.
Giacomini, Hector, Neukirch, Sébastien
openaire   +4 more sources

Exact Discrete Stochastic Simulation With Deep‐Learning‐Scale Gradient Optimization

open access: yesAdvanced Science, EarlyView.
A 203,796‐parameter gene regulatory network classifies handwritten digits with 98.4% accuracy using exact stochastic dynamics. The framework decouples forward simulation from backward differentiation, making continuous‐time Markov chain models compatible with deep‐learning optimization.
Jose M. G. Vilar, Leonor Saiz
wiley   +1 more source

A Class of Quintic Kolmogorov Systems with Explicit Non-algebraic Limit Cycle [PDF]

open access: yesJournal of Siberian Federal University. Mathematics & Physics, 2019
Various physical, ecological, economic, etc phenomena are governed by planar differential systems. Sub- sequently, several research studies are interested in the study of limit cycles because of their interest in the understanding of these systems. The aim of this paper is to investigate a class of quintic Kolmogorov systems, namely systems of the form
Bendjeddou, Ahmed, Grazem, Mohamed
openaire   +3 more sources

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