Journal of Mathematical Chemistry最新文献_第6页

Correction: Why local softness and local hyper-softness are more appropriate local reactivity descriptors than dual descriptor and Fukui functions? 更正：为什么局部软度和局部超软度是比双重描述符和福井函数更合适的局部反应性描述符？

IF 1.7 3区化学

Journal of Mathematical Chemistry Pub Date : 2024-05-28 DOI: 10.1007/s10910-024-01629-1

Jorge I. Martínez-Araya

引用次数: 0

A new type of energy-preserving integrators for quasi-bi-Hamiltonian systems 准双哈密尔顿系统的新型能量守恒积分器

IF 1.7 3区化学

Journal of Mathematical Chemistry Pub Date : 2024-05-15 DOI: 10.1007/s10910-024-01624-6

Kai Liu, Ting Fu, Wei Shi, Xuhuan Zhou

{"title":"A new type of energy-preserving integrators for quasi-bi-Hamiltonian systems","authors":"Kai Liu, Ting Fu, Wei Shi, Xuhuan Zhou","doi":"10.1007/s10910-024-01624-6","DOIUrl":"10.1007/s10910-024-01624-6","url":null,"abstract":"<div><p>Energy-preserving algorithms, as one of the core research areas in numerical ordinary differential equations, have achieved great success by many methods such as symplectic methods and discrete gradient methods. This paper considers the numerical integration of quasi-bi-Hamiltonian systems, which, as a generalization of bi-Hamiltonian systems, can be expressed in two distinct ways: <span>({dot{y}} = P _ { 1 } ( y ) nabla H _ { 2 }(y) = frac{1}{rho (y)}P _ { 2 } ( y ) nabla H _ { 1 }(y))</span>. The quasi-bi-Hamiltonian systems have two Hamiltonians <span>(H_1(y))</span> and <span>(H_2(y))</span>. Conventional discrete gradient methods can only preserve one Hamiltonian at a time. In this paper, based on discrete gradient and projection, new energy-preserving integrators that can preserve the two Hamiltonians simultaneously are proposed. They show better qualitative behaviours than traditional discrete gradient methods do. Numerical integrations of Hénon-Heiles type systems and the Korteweg-de Vries (KdV) equation are conducted to show the effectiveness of the new integrators in comparison with traditional discrete gradient methods.</p></div>","PeriodicalId":648,"journal":{"name":"Journal of Mathematical Chemistry","volume":"62 7","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140972943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Positive steady states of a class of power law systems with independent decompositions 一类具有独立分解的幂律系统的正稳态

IF 1.7 3区化学

Journal of Mathematical Chemistry Pub Date : 2024-05-14 DOI: 10.1007/s10910-024-01622-8

Al Jay Lan J. Alamin, Bryan S. Hernandez

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A low-cost, two-step fourteenth-order phase-fitting approach to tackling problems in chemistry 解决化学问题的低成本、两步十四阶相位拟合方法

IF 1.7 3区化学

Journal of Mathematical Chemistry Pub Date : 2024-05-09 DOI: 10.1007/s10910-024-01615-7

Marina A. Medvedeva, T. E. Simos

引用次数: 0

Fusene chains revisited: how kinky they are and why it matters 重温富森链：它们有多奇特以及为何如此重要

IF 1.7 3区化学

Journal of Mathematical Chemistry Pub Date : 2024-05-07 DOI: 10.1007/s10910-024-01620-w

Tomislav Došlić

引用次数: 0

An innovative Vieta–Fibonacci wavelet collocation method for the numerical solution of three-component Brusselator reaction diffusion system of fractional order 用于分数阶三组份布鲁塞尔反应扩散系统数值求解的创新 Vieta-Fibonacci 小波配位法

IF 1.7 3区化学

Journal of Mathematical Chemistry Pub Date : 2024-05-02 DOI: 10.1007/s10910-024-01621-9

Manpal Singh, S. Das, Rajeev

{"title":"An innovative Vieta–Fibonacci wavelet collocation method for the numerical solution of three-component Brusselator reaction diffusion system of fractional order","authors":"Manpal Singh, S. Das,  Rajeev","doi":"10.1007/s10910-024-01621-9","DOIUrl":"10.1007/s10910-024-01621-9","url":null,"abstract":"<div><p>The research article presents a novel approach for the numerical solution of three-component time fractional order Brusselator reaction-diffusion system using the innovative Vieta–Fibonacci wavelet and collocation method. The proposed method involves the derivation of operational matrices for both integer and fractional order derivatives, enable the accurate and efficient computation of the system. The existence, uniqueness of solution and Ulam–Hyers stability of the model are rigorously discussed. Furthermore, a comprehensive convergence analysis of the Vieta–Fibonacci wavelet method is presented, which demonstrates its effectiveness in approximating the fractional derivative of the Brusselator system. The numerical experiments showcase the superior performance of the method in terms of accuracy and computational efficiency. The application of the Vieta–Fibonacci wavelet method to the three-component fractional order Brusselator reaction-diffusion system marks a significant advancement in the field of computational mathematics. The successful implementation of the Vieta–Fibonacci wavelet method signifies a significant advancement in solving fractional-order reaction-diffusion problems.</p></div>","PeriodicalId":648,"journal":{"name":"Journal of Mathematical Chemistry","volume":"62 7","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140888235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical representations of AB-type copolymer complexes: analysis of 1H NMR chemical shift patterns in terms of a Smith–Cantor set AB 型共聚物复合物的数字表示：根据 Smith-Cantor 集合分析 1H NMR 化学位移模式

IF 1.7 3区化学

Journal of Mathematical Chemistry Pub Date : 2024-04-30 DOI: 10.1007/s10910-024-01614-8

Howard M. Colquhoun, Ricardo Grau-Crespo

{"title":"Numerical representations of AB-type copolymer complexes: analysis of 1H NMR chemical shift patterns in terms of a Smith–Cantor set","authors":"Howard M. Colquhoun, Ricardo Grau-Crespo","doi":"10.1007/s10910-024-01614-8","DOIUrl":"10.1007/s10910-024-01614-8","url":null,"abstract":"<div><p>When considering the possibility of storing information in the sequence of monomer residues within an AB-type copolymer chain, it is constructive to model that sequence as a string of ones and zeros. The intramolecular environment around any given digit (say a “<b>1</b>”) can then be represented by another string of integers—a <i>code</i>—obtained by summing pairs of digits at equivalent positions, in both directions, from that digit. The code can include only integers 0, 1 and 2, and can represent a number in any base <i>b</i> higher than 2. In base <i>b</i> = 3 the resulting set of codes includes <i>all</i> numbers (because only digits 0, 1 and 2 occur in ternary expansions), but in any base <i>b</i> > 3 the codes define a limited set of numbers comprising a fractal we term a Smith–Cantor set. The <sup>1</sup>H NMR spectrum of a random, AB-type co(polyester-imide) shows, on complexation with pyrene, a pattern of complexation shifts approximating very closely to the Smith–Cantor set for which <i>b</i> = 4. Other co(polyimide) complexes show a <sup>1</sup>H NMR pattern corresponding to a specific <i>sub</i>-set of this fractal. The sub-set arises from a “stop-at-zero” limitation, whereby digits in the initial string are set to zero for code-generating purposes if they occur beyond a zero, as viewed from the central “<b>1</b>”. The limitation arises in copolymers where pyrene binds by intercalation between <i>pairs</i> of adjacent diimide residues. This numerical approach provides a complete, unifying theory to account for the emergence of fractal character in the <sup>1</sup>H NMR spectra of AB-type copolymer complexes.</p></div>","PeriodicalId":648,"journal":{"name":"Journal of Mathematical Chemistry","volume":"62 7","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10910-024-01614-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Family of phase fitted 3-step second-order BDF methods for solving periodic and orbital quantum chemistry problems 用于解决周期和轨道量子化学问题的相位拟合三步二阶 BDF 方法系列

IF 1.7 3区化学

Journal of Mathematical Chemistry Pub Date : 2024-04-30 DOI: 10.1007/s10910-024-01619-3

Hosein Saadat, Sanaz Hami Hassan Kiyadeh, Ramin Goudarzi Karim, Ali Safaie

{"title":"Family of phase fitted 3-step second-order BDF methods for solving periodic and orbital quantum chemistry problems","authors":"Hosein Saadat, Sanaz Hami Hassan Kiyadeh, Ramin Goudarzi Karim, Ali Safaie","doi":"10.1007/s10910-024-01619-3","DOIUrl":"10.1007/s10910-024-01619-3","url":null,"abstract":"<div><p>In this paper, we introduce a novel series of second-order Backward Differentiation Formulas (BDFs) specifically designed to address phase-lag and its first derivative in the numerical resolution of Initial Value Problems (IVPs) with orbital solutions. Our methodology commences with an in-depth analysis of phase-lag phenomena associated with second-order BDFs. Following this, we construct a suite of equations by embedding algebraic functions into the operational framework of the 3-step second-order BDF (SOBDF) method. Additionally, we elaborate on equations that precisely describe the phase-lag and its derivatives, with a concentrated focus on the 3-step SOBDF method. The culmination of this work is the presentation of six distinct methods, each methodically crafted to negate both the real and imaginary elements of phase-lag and its derivatives in numerical computations. The study advances with a meticulous examination of the local truncation error and the stability regions pertinent to the six phase-fitted methods introduced. Furthermore, we scrutinize their computational performance by deploying these methods across a spectrum of initial value problems, offering valuable insights into their effectiveness in varying contexts.</p></div>","PeriodicalId":648,"journal":{"name":"Journal of Mathematical Chemistry","volume":"62 6","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140838555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluation of smooth reaction rate of noisy experimental data using Legendre series expansion 利用 Legendre 序列展开评估噪声实验数据的平稳反应速率

IF 1.7 3区化学

Journal of Mathematical Chemistry Pub Date : 2024-04-28 DOI: 10.1007/s10910-024-01618-4

Alireza Aghili, Amir Hossein Shabani

{"title":"Evaluation of smooth reaction rate of noisy experimental data using Legendre series expansion","authors":"Alireza Aghili, Amir Hossein Shabani","doi":"10.1007/s10910-024-01618-4","DOIUrl":"10.1007/s10910-024-01618-4","url":null,"abstract":"<div><p>The accurate calculation of reaction rates from experimental data is crucial for understanding and characterizing chemical processes. However, the presence of noise in experimental data can introduce errors in rate calculations. In this study, we introduced a novel approach that utilizes the Legendre series expansion method to directly derive smooth reaction rates from noisy experimental data, eliminating the need for numerical differentiation methods. This approach proves to be highly effective in handling noisy thermogravimetric analysis (TGA) data obtained from the thermal decomposition of specific polymers. We demonstrated the robustness and reliability of this method and provided Gnu Octave codes as a free alternative to MATLAB, making the implementation more accessible. Furthermore, the smooth reaction rates obtained were used to evaluate the activation energy using the Friedman isoconversional method. The results showed excellent agreement with those obtained using the Vyazovkin integral method. Additionally, the proposed method can be applied to obtain smooth derivative thermogravimetric (DTG) curves using noisy TGA data set.</p></div>","PeriodicalId":648,"journal":{"name":"Journal of Mathematical Chemistry","volume":"62 7","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140810685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Endotactic and strongly endotactic networks with infinitely many positive steady states 具有无限多正稳态的内向和强内向网络

IF 1.7 3区化学

Journal of Mathematical Chemistry Pub Date : 2024-04-26 DOI: 10.1007/s10910-024-01617-5

Samay Kothari, Abhishek Deshpande

引用次数: 0