Computers & chemistry最新文献_第6页

Theoretical Study of the Morphologically Originated Noise Associated with the Transmittance of a Precipitation System 形态源噪声与降水系统透射率相关的理论研究

Computers & chemistry Pub Date : 2002-01-01 DOI: 10.1016/S0097-8485(01)00090-0

J. A. Poce-Fatou, R. Bañares-Alcántara, Joaquín Martín

引用次数: 0

Differential fraction-based kinetic model for simulating hydrodesulfurization process of petroleum fraction 基于差分馏的石油馏分加氢脱硫动力学模型

Computers & chemistry Pub Date : 2002-01-01 DOI: 10.1016/S0097-8485(01)00091-2

Weixiang Zhao, Dezhao Chen, Shangxu Hu

引用次数: 6

Estimation of the chemical rank for the three-way data: a principal norm vector orthogonal projection approach 三向数据的化学等级估计:主范数向量正交投影法

Computers & chemistry Pub Date : 2002-01-01 DOI: 10.1016/S0097-8485(01)00110-3

Xie Hong-Ping , Jiang Jian-Hui , Shen Guo-Li , Yu Ru-Qin

{"title":"Estimation of the chemical rank for the three-way data: a principal norm vector orthogonal projection approach","authors":"Xie Hong-Ping , Jiang Jian-Hui , Shen Guo-Li , Yu Ru-Qin","doi":"10.1016/S0097-8485(01)00110-3","DOIUrl":"10.1016/S0097-8485(01)00110-3","url":null,"abstract":"<div><p>A new approach for estimating the chemical rank of the three-way array called the principal norm vector orthogonal projection method has been proposed. The method is based on the fact that the chemical rank of the three-way data array is equal to one of the column space of the unfolded matrix along the spectral or chromatographic mode. A vector with maximum Frobenius norm is selected among all the column vectors of the unfolded matrix as the principal norm vector (PNV). A transformation is conducted for the column vectors with an orthogonal projection matrix formulated by PNV. The mathematical rank of the column space of the residual matrix thus obtained should decrease by one. Such orthogonal projection is carried out repeatedly till the contribution of chemical species to the signal data is all deleted. At this time the decrease of the mathematical rank would equal that of the chemical rank, and the remaining residual subspace would entirely be due to the noise contribution. The chemical rank can be estimated easily by using an <em>F</em>-test. The method has been used successfully to the simulated HPLC-DAD type three-way data array and two real excitation–emission fluorescence data sets of amino acid mixtures and dye mixtures. The simulation with added relatively high level noise shows that the method is robust in resisting the heteroscedastic noise. The proposed algorithrn is simple and easy to program with quite light computational burden.</p></div>","PeriodicalId":79331,"journal":{"name":"Computers & chemistry","volume":"26 2","pages":"Pages 183-190"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0097-8485(01)00110-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56174733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

High-order spatial discretisations in electrochemical digital simulation. Part 3. Combination with the explicit Runge–Kutta algorithm 电化学数字仿真中的高阶空间离散。第3部分。结合显式龙格-库塔算法

Computers & chemistry Pub Date : 2002-01-01 DOI: 10.1016/S0097-8485(01)00086-9

D Britz , O Østerby , J Strutwolf , T Koch Svennesen

引用次数: 11

Radial basis function neural network based QSPR for the prediction of critical pressures of substituted benzenes 基于径向基函数神经网络的QSPR取代苯临界压力预测

Computers & chemistry Pub Date : 2002-01-01 DOI: 10.1016/S0097-8485(01)00093-6

Xiaojun Yao , Xiaoyun Zhang , Ruisheng Zhang , Mancang Liu , Zhide Hu , Botao Fan

引用次数: 25

P-stable eighth algebraic order methods for the numerical solution of the Schrödinger equation Schrödinger方程数值解的p稳定八阶代数方法

Computers & chemistry Pub Date : 2002-01-01 DOI: 10.1016/S0097-8485(01)00085-7

A. Konguetsof, T.E. Simos

引用次数: 7

Radial Basis Function Neural Network Based QSPR for the Prediction of Critical Pressures of Substituted Benzenes 基于径向基函数神经网络的QSPR取代苯临界压力预测

Computers & chemistry Pub Date : 2002-01-01 DOI: 10.1016/S0097-8485(01)00093-6

X. Yao, Xiaoyun Zhang, Ruisheng Zhang, Mancang Liu, Zhide Hu, B. Fan

引用次数: 25

High-order Spatial Discretisations in Electrochemical Digital Simulation. Part 3. Combination with the Explicit Runge-Kutta Algorithm 电化学数字仿真中的高阶空间离散。第3部分。结合显式龙格-库塔算法

Computers & chemistry Pub Date : 2002-01-01 DOI: 10.1016/S0097-8485(01)00086-9

D. Britz, O. Østerby, J. Strutwolf, Tom Koch Svennesen

引用次数: 11

Numerical analysis of Horvath–Kawazoe equation Horvath-Kawazoe方程的数值分析

Computers & chemistry Pub Date : 2002-01-01 DOI: 10.1016/S0097-8485(01)00088-2

P Kowalczyk , A.P Terzyk , P.A Gauden , L Solarz

引用次数: 21

Theoretical study of the internal rotational barriers in nitrotoluenes, nitrophenols, and nitroanilines 硝基甲苯、硝基酚和硝基苯胺内部旋转势垒的理论研究

Computers & chemistry Pub Date : 2002-01-01 DOI: 10.1016/S0097-8485(01)00105-X

P.C Chen, S.C Chen

{"title":"Theoretical study of the internal rotational barriers in nitrotoluenes, nitrophenols, and nitroanilines","authors":"P.C Chen, S.C Chen","doi":"10.1016/S0097-8485(01)00105-X","DOIUrl":"https://doi.org/10.1016/S0097-8485(01)00105-X","url":null,"abstract":"<div><p>The molecular geometries and internal rotational barriers of the nitro group of 3-nitrotoluene (3-NT), 4-nitrotoluene (4-NT), 3-nitrophenol (3-NP), 4-nitrophenol (4-NP), 3-nitroaniline (3-NA), and 4-nitroaniline (4-NA) were calculated by five different types of density functional theory (DFT) methods with three different levels of basis sets. Analyses of the torsional angles of the nitro, methyl, amino, and hydroxyl groups indicate that 3-NP, and 4-NP are planar molecules, but 3-NT, 4-NT, 3-NA, and 4-NA are not planar molecules. Internal rotational barriers of the nitro group were calculated as the V<sub>2</sub> barrier, and the NO<sub>2</sub> torsional potentials for each molecule were given. The heights of the V<sub>2</sub> barrier vary with the DFT methods, the basis sets, and the kinds and positions of substituents. The average values of the V<sub>2</sub> barriers for 3-NT, 4-NT, 3-NP, 4-NP, 3-NA, and 4-NA are 6.44, 6.92, 6.64, 7.93, 6.38, and 9.13 kcal/mol, respectively. Torsional potentials of the OH and NH<sub>2</sub> groups of nitrophenol and nitroaniline derivatives were also studied by a B3LYP/6-31G* approach. Except for the OH group in 2-NP, these derivatives have the V<sub>2</sub> barrier.</p></div>","PeriodicalId":79331,"journal":{"name":"Computers & chemistry","volume":"26 2","pages":"Pages 171-178"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0097-8485(01)00105-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91666154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19