中文
相关论文

相关论文: Simple Alcohols with the Lowest Normal Boiling Poi…

200 篇论文

Measures of the irregularity of chemical graphs could be helpful for QSAR/QSPR studies and for the descriptive purposes of biological and chemical properties, such as melting and boiling points, toxicity and resistance. Here we consider the…

离散数学 · 计算机科学 2016-08-19 Hosam Abdo , Darko Dimitrov , Wei Gao

In this paper, the investigates Adriatic indices, specifically the sum lordeg index where it defined as $SL(G) = \sum_{u \in V(G)} \deg_G(u) \sqrt{\ln \deg_G(u)}$ and the variable sum exdeg index $SEI_a(G)$ for $a>0$, $a\neq 1$. We present…

组合数学 · 数学 2025-08-07 Jasem Hamoud , Duaa Abdullah

The first Zagreb index $M_{1}$ of a graph is defined as the sum of the square of every vertex degree, and the second Zagreb index $M_{2}$ of a graph is defined as the sum of the product of vertex degrees of each pair of adjacent vertices.…

组合数学 · 数学 2020-06-02 Xiaocong He , Xiaobo He

The problem of characterizing trees with minimal atom-bond-connectivity index (minimal-ABC trees) has a reputation as one of the most demanding recent open optimization problems in mathematical chemistry. Here firstly, we give an…

组合数学 · 数学 2022-01-21 Darko Dimitrov , Zhibin Du

The generalized hierarchical product of graphs was introduced by L. Barri\'ere et al in 2009. In this paper, reformulated first Zagreb index of generalized hierarchical product of two connected graphs and hence as a special case cluster…

离散数学 · 计算机科学 2017-04-20 Nilanjan De

A simple topological graph is a topological graph in which any two edges have at most one common point, which is either their common endpoint or a proper crossing. More generally, in a k-simple topological graph, every pair of edges has at…

计算几何 · 计算机科学 2016-02-22 Péter Hajnal , Alexander Igamberdiev , Günter Rote , André Schulz

Let $G=(V,E)$ be a finite simple graph. The Graovac-Ghorbani index of a graph G is defined as $ABC_{GG}(G)=\sum_{uv\in E(G)}\sqrt{\frac{n_u(uv,G)+n_v(uv,G)-2}{n_u(uv,G)n_v(uv,G)}},$ where $n_u(uv,G)$ is the number of vertices closer to…

组合数学 · 数学 2022-02-07 Nima Ghanbari

The Wiener index W(G) of a connected graph $G$ is the sum of distances between all pairs of vertices in G$. In this paper, we first give the recurrences or explicit formulae for computing the Wiener indices of spiro and polyphenyl hexagonal…

组合数学 · 数学 2010-06-30 Hanyuan Deng

Topological indices play an important role in mathematical chemistry especially in the quantitative structure-property relationship (QSPR) and quantitative structure-activity relationship (QSAR). Recent research indicates that the augmented…

组合数学 · 数学 2016-07-26 Akbar Ali , Zahid Raza , Akhlaq Ahmad Bhatti

For a graph $G$, the first multiplicative Zagreb index $\prod_1$ is equal to the product of squares of the vertex degrees, and the second multiplicative Zagreb index $\prod_2$ is equal to the product of the products of degrees of pairs of…

组合数学 · 数学 2016-11-21 Shaohui Wang , Chunxiang Wang , Jia-Bao Liu

The Wiener index of a connected graph is the sum of distances between all unordered pairs of vertices. Sam Spiro [The Wiener index of signed graphs, Appl. Math. Comput., 416(2022)126755] recently introduced the Wiener index for a signed…

组合数学 · 数学 2022-08-04 Songlin Guo , Wei Wang , Chuanming Wang

The Wiener index of a (hyper)graph is calculated by summing up the distances between all pairs of vertices. We determine the maximum possible Wiener index of a connected $n$-vertex $k$-uniform hypergraph and characterize for every~$n$ all…

组合数学 · 数学 2023-02-20 Stijn Cambie , Ervin Győri , Nika Salia , Casey Tompkins , James Tuite

In the past decade, there has been a significant interest in the use of machine learning approaches in materials science research. Conventional deep learning approaches that rely on complex, nonlinear models have become increasingly…

材料科学 · 物理学 2025-10-02 Andrew Ma , Marin Soljačić

Weighted Szeged index is a recently introduced extension of the well-known Szeged index. In this paper, we present a new tool to analyze and characterize minimum weighted Szeged index trees. We exhibit the best trees with up to 81 vertices…

组合数学 · 数学 2020-07-22 Pavol Hell , César Hernández-Cruz , Seyyed Aliasghar Hosseini

We introduce an atomistic classifier based on a combination of spectral graph theory and a Voronoi tessellation method. This classifier allows for the discrimination between structures from different minima of a potential energy surface,…

化学物理 · 物理学 2024-07-19 Andreas Møller Slavensky , Bjørk Hammer

In this paper we obtain bounds on a very general class of distance-based topological indices of graphs, which includes the Wiener index, defined as the sum of the distances between all pairs of vertices of the graph, and most…

组合数学 · 数学 2024-11-21 Peter Dankelmann

The new methodical approach of using ethanol as internal standard in gas chromatographic analysis of volatile compounds in spirit drinks in daily practice of testing laboratories is proposed. This method provides determination of volatile…

Possible crystalline modifications of chemical compounds at low temperatures correspond to local minima of the energy landscape. Determining these minima via simulated annealing is one method for the prediction of crystal structures, where…

材料科学 · 物理学 2008-10-31 K. Doll , J. C. Schoen , M. Jansen

The transmission of a vertex $v$ in a (chemical) graph $G$ is the sum of distances from $v$ to other vertices in $G$. If any two vertices of $G$ have different transmissions, then $G$ is transmission irregular. The Wiener index $W(G)$ of a…

组合数学 · 数学 2026-01-26 Ivan Damnjanović , Anran Xu , Kexiang Xu

Continuing the recent work of L. Zhong and K. Xu [MATCH Commun. Math. Comput. Chem.71(2014) 627-642], we determine inequalities among several vertex-degree-based topological indices; first geometric-arithmetic index(GA), augmented Zagreb…

组合数学 · 数学 2017-09-26 Akbar Ali , Akhlaq Ahmad Bhatti , Zahid Raza