Element cycles are the biogeochemical pathways by which elements are transformed and moved through various states by geological and biological processes. Uncover the latest and most impactful research in Element cycles. Explore pioneering discoveries, insightful ideas and new methods from leading researchers in the field.
This paper is concerned with the bifurcation of critical periods from the isochronous center of the cubic Kukles system under sufficiently small polynomial perturbations of degree nthat preserve the center at the origin. For a suitable...
In this paper, we study the number of limit cycles of a near-Hamiltonian system \(\dot{x}=y+\varepsilon P(x,y,a),\) x ˙ = y + ε P ( x , y , a ) , \(\dot{y}=-x+x^3+\varepsilon Q(x,y,a)\) y ˙ = - x + x 3 + ε Q ( x , y , a ) . When P, Q are n-degree...
We study upper bounds for the moment of permanent \(\varepsilon \) ε -saturation in finite metric graphs. The dynamics is generated by moving points travelling with unit speed along edges and branching into all outgoing directions whenever they reach...
Let k be a positive integer. A graph is said to be \((P_2 \cup kP_1)\) ( P 2 ∪ k P 1 ) -free if it does not contain \(P_2 \cup kP_1\) P 2 ∪ k P 1 as an induced subgraph. Recently, Ota and the author asked whether every 1-tough and k-connected ...
We prove the Gersten conjecture for p-adic étale Tate twists for a smooth scheme X in mixed characteristic in the Nisnevich topology. Our main observation is that, while p-adic étale Tate twists are not \(\mathbb A^1\) A 1 -invariant, for the proof...
Using methods from algebraic number theory, we establish necessary and sufficient conditions for the existence of linear complementary dual (LCD), self-dual, and isodual cyclic codes over finite commutative principal ideal rings. We present explicit...
In this paper, we establish new characterizations of hypo-EP elements in unital \(C^*\) C ∗ -algebras using Moore–Penrose inverses, group inverses, and representation theory. By employing the Gelfand–Naimark–Segal construction and Douglas’s...
Suppose C(G) denotes the set of all cyclic subgroups of a finite group G, and \(\mathcal {O}_{2}(G)\) O 2 ( G ) denotes the number of elements of order 2 in G. An open problem in the literature asks for a classification of groups G with ...
To accurately assess the service accessibility of networks using preset cycles (p-cycles), we construct a theoretical model in this research. Compared to earlier work, our model is able to predict service availability more accurately by taking into...
Given two graphs G and F, if G contains a copy of F, then the rainbow number of F in G, denoted by rb(G, F), is the minimum positive integer t such that any t-edge-coloring of G contains a rainbow copy of F. Let \(\mathcal {M}_{n}(F)\)...
The n-dimensional hypercube \(Q_n\) Q n is a fundamental interconnection network in parallel computing. In practice, link failures and prescribed connection demands must be accommodated simultaneously. This paper studies the existence of a...
Isomorphism detection in epicyclic gear trains (EGTs) is an important step in mechanism topological analysis and structural synthesis because it enables the identification and elimination of duplicate or structurally equivalent mechanisms. Although...
The Sombor index \( SO(G)=\sum _{uv\in E(G)} \sqrt{d_G(u)^2 + d_G(v)^2} \) S O ( G ) = ∑ u v ∈ E ( G ) d G ( u ) 2 + d G ( v ) 2 is a highly predictive, vertex–degree–based topological descriptor. Building on earlier results for trees and unicyclic...
The decycling number \(\nabla (G)\) ∇ ( G ) (connected decycling number \(\nabla _{1}(G)\) ∇ 1 ( G ) ) of a graph G is the smallest number of vertices which can be deleted from Gso that the resulting graph is a forest (a subtree). A decycling set...
Cyclic polymers exhibit physical properties distinct from those of their linear polymer counterparts. Although cyclic polymer materials with advanced designs can be synthesized using methods that control their molecular weight, dispersity, and...
Hecke–Kiselman monoids were first defined by O. Ganyushkin and V. Mazorchuk in the study of Kiselman quotients of 0-Hecke monoids. The Cycle monoid \(Cyc_{n}\) C y c n is the Hecke–Kiselman monoid associated to a cycle consisting of \(n\geqslant 3\)...
A covering of a digraph D by Hamilton cycles is a collection of directed Hamilton cycles (not necessarily edge-disjoint) that together cover all the edges of D. We prove that for \(1/2 \geq p \geq \frac{\log^{20} n}{n}\) 1 / 2 ≥ p ≥ ...
An injective edge-coloring of a graph G is an assignment of colors to the edges of G such that two distinct edges e and f receive distinct colors whenever 1) e and f are in a common triangle; or 2) \(\{e,f\}\) { e , f } forms a matching and there is...
An outer multiset resolving set uniquely identifies the vertices of a given graph. A subset \(W \subseteq V(G)\) W ⊆ V ( G ) is an outer multiset resolving set if every two distinct vertices in \(V(G){\setminus } W\) V ( G ) \ W have distinct...
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Graphs and Combinatoricsprimarily publishes original research papers in the field of combinatorial mathematics. The scope of the journal includes,...
The Journal of Phase Equilibria and Diffusion (JPED)is an archival, peer-reviewed, bimonthly publication that focuses on the crystallographic,...
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Honorary Founder: Pál Erdõs (1913-1996) COMBINATORICA is an international journal of the J. Bolyai Mathematical Society (Fõ utca 68., 1027 Budapest,...
