共查询到20条相似文献,搜索用时 46 毫秒
1.
Fukun Zhao Leiga Zhao Yanheng Ding 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2011,15(6):495-511
This paper is concerned with the following periodic Hamiltonian elliptic system
{l-Du+V(x)u=g(x,v) in \mathbbRN,-Dv+V(x)v=f(x,u) in \mathbbRN,u(x)? 0 and v(x)?0 as |x|?¥,\left \{\begin{array}{l}-\Delta u+V(x)u=g(x,v)\, {\rm in }\,\mathbb{R}^N,\\-\Delta v+V(x)v=f(x,u)\, {\rm in }\, \mathbb{R}^N,\\ u(x)\to 0\, {\rm and}\,v(x)\to0\, {\rm as }\,|x|\to\infty,\end{array}\right. 相似文献
2.
Takuro Fukunaga 《Graphs and Combinatorics》2011,27(5):647-659
An undirected graph G = (V, E) is called
\mathbbZ3{\mathbb{Z}_3}-connected if for all
b: V ? \mathbbZ3{b: V \rightarrow \mathbb{Z}_3} with ?v ? Vb(v)=0{\sum_{v \in V}b(v)=0}, an orientation D = (V, A) of G has a
\mathbbZ3{\mathbb{Z}_3}-valued nowhere-zero flow
f: A? \mathbbZ3-{0}{f: A\rightarrow \mathbb{Z}_3-\{0\}} such that ?e ? d+(v)f(e)-?e ? d-(v)f(e)=b(v){\sum_{e \in \delta^+(v)}f(e)-\sum_{e \in \delta^-(v)}f(e)=b(v)} for all v ? V{v \in V}. We show that all 4-edge-connected HHD-free graphs are
\mathbbZ3{\mathbb{Z}_3}-connected. This extends the result due to Lai (Graphs Comb 16:165–176, 2000), which proves the
\mathbbZ3{\mathbb{Z}_3}-connectivity for 4-edge-connected chordal graphs. 相似文献
3.
If G has a nilpotent normal p-complement and V is a finite, faithful and completely reducible G-module of characteristic p, we prove that there exist ${v_1, v_2 \in V}
4.
A Roman dominating function on a graph G = (V, E) is a function f : V ? {0, 1, 2}f : V \rightarrow \{0, 1, 2\} satisfying the condition that every vertex v for which f(v) = 0 is adjacent to at least one vertex u for which f(u) = 2. The weight of a Roman dominating function is the value w(f) = ?v ? V f(v)w(f) = \sum_{v\in V} f(v). The Roman domination number of a graph G, denoted by gR(G)_{\gamma R}(G), equals the minimum weight of a Roman dominating function on G. The Roman domination subdivision number sdgR(G)sd_{\gamma R}(G) is the minimum number of edges that must be subdivided (each edge in G can be subdivided at most once) in order to increase the Roman domination number. In this paper, first we establish upper
bounds on the Roman domination subdivision number for arbitrary graphs in terms of vertex degree. Then we present several
different conditions on G which are sufficient to imply that $1 \leq sd_{\gamma R}(G)
\leq 3$1 \leq sd_{\gamma R}(G)
\leq 3. Finally, we show that the Roman domination subdivision number of a graph can be arbitrarily large. 相似文献
5.
Sami Baraket Ines Ben Omrane Taieb Ouni 《NoDEA : Nonlinear Differential Equations and Applications》2011,18(1):59-78
Given a bounded open regular set
W ì \mathbbR2{\Omega \subset \mathbb{R}^2} and x1, x2, ?, xm ? W{x_1, x_2, \ldots, x_m \in \Omega}, we give a sufficient condition for the problem
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