本文利用Web of Science数据库，构建出数学、电化学、信息计量学和传播学4个领域的高频共关键词网络。用于反映领域核心知识。此类网络以关键词为节点，当两个关键词用于同一论文中时就形成节点之间的连接。核心／边缘分析和网络分析...本文利用Web of Science数据库，构建出数学、电化学、信息计量学和传播学4个领域的高频共关键词网络。用于反映领域核心知识。此类网络以关键词为节点，当两个关键词用于同一论文中时就形成节点之间的连接。核心／边缘分析和网络分析参数表明核心关键词数量增长速度低于关键词总量增速。依据核心关键词表达核心知识概念的逻辑，推论特定知识领域中稳定的核心概念及其共现网络反映了该领域相对稳定的核心知识及其结构。展开更多
Let G be a finite group andπ(G)be the set of prime divisors of∣G∣.The prime graphΓ(G)of G is the graph with vertex setπ(G),and different p,q∈π(G)are joined by an edge if and only if G has an element of order pq...Let G be a finite group andπ(G)be the set of prime divisors of∣G∣.The prime graphΓ(G)of G is the graph with vertex setπ(G),and different p,q∈π(G)are joined by an edge if and only if G has an element of order pq.In this paper,we characterize the finite solvable groups whose prime graphs have diameter 3.展开更多
文摘本文利用Web of Science数据库，构建出数学、电化学、信息计量学和传播学4个领域的高频共关键词网络。用于反映领域核心知识。此类网络以关键词为节点，当两个关键词用于同一论文中时就形成节点之间的连接。核心／边缘分析和网络分析参数表明核心关键词数量增长速度低于关键词总量增速。依据核心关键词表达核心知识概念的逻辑，推论特定知识领域中稳定的核心概念及其共现网络反映了该领域相对稳定的核心知识及其结构。
基金Supported by the NSF of China(No.12171058)the NSF of Jiangsu Province(No.BK20231356)。
文摘Let G be a finite group andπ(G)be the set of prime divisors of∣G∣.The prime graphΓ(G)of G is the graph with vertex setπ(G),and different p,q∈π(G)are joined by an edge if and only if G has an element of order pq.In this paper,we characterize the finite solvable groups whose prime graphs have diameter 3.
