检索结果-南通市图书馆

Modeling of bentonite/sepiolite plastic concrete compressive strength using artificial neural network and support vector machine

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2019年第1期13卷 215-239页

作者： ali reza GHANIZADEH Hakime ABBASLOU Amir Tavana AMLASHI Pourya aliDOUST Department of Civil Engineering Sirjan University of TechnologySirjanIran Department of Civil Engineering Iran University of Science & TechnologyTehranIran

Plastic concrete is an engineering material,which is commonly used for construction of cut-offwalls to prevent water seepage under the *** paper aims to explore two machine learning algorithms including artificial neural network (ANN)and support vector machine (SVM)to predict the compressive strength of bentonite/sepiolite plastic *** this purpose,two unique sets of 72 data for compressive strength of bentonite and sepiolite plastic concrete samples (totally 144 data)were prepared by conducting an experimental *** results confirm the ability of ANN and SVM models in prediction ***,Sensitivity analysis of the best obtained model indicated that cement and silty clay have the maximum and minimum influences on the compressive strength,*** addition, investigation of the effect of measurement error of input variables showed that change in the sand content (amount)and curing time will have the maximum and minimum effects on the output mean absolute percent error (MAPE)of model, ***,the influence of different variables on the plastic concrete compressive strength values was evaluated by conducting parametric studies.

关键词： bentonite/sepiolite plastic concrete compressive strength artificial neural network support vector machine parametric analysis

The information technology barriers in supply chain of sugarcane in Khuzestan province,Iran:A combined ANP-DEMATEL approach

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Information Processing in Agriculture 2021年第3期8卷 458-468页

作者： reza Salehi Mohammad ali Asaadi Mahmood Haji Rahimi ali Mehrabi Department of Business Management Shahid Chamran University of AhvazAhvazIran Department of Agricultural Economics Engineering Faculty of AgricultureTarbiat Modares UniversityTehranIran Department of Agricultural Economics Engineering Faculty of AgricultureUniversity of KurdistanKurdistanIran

The present study aims at identifying and also prioritizing information technology barriers in supply chain of sugarcane in Khuzestan *** statistical population of the study consisted of all senior managers of sugarcane industries in the *** four large rel-evant companies in the field,34 senior managers were *** required data was col-lected through two stages hiring *** order to evaluate information technology barriers at the supply chain level,six main dimensions were considered includ-ing technological,supply chain management,strategic,organizational,individual and cus-tomer *** technique was also used to identify the relationship between indicators,and the ANP method was also employed to prioritize the before mentioned *** results of DEMATEL showed that strategic barrier indicator acts as the most influ-ential,and the supply chain management barrier indicator as the most impotent *** results of ANP method showed that of all research indicators,customer barrier indicator(weight 0.00127)was the most important ***,organizational and supply chain management barrier indicators are ranked second and third,***,among the 28 research components(sub-criteria),the“lack of financial support”component with the weight of 0.04821 ranked first,followed by“poor outsourcing management”and“high investment and installation costs”as second and third respectively,which also had the most impact on the sugarcane supply chain.

关键词： Information technology Supply chain management Sugarcane ANP DEMATEL

Electrospinning of Nylon-6,6 Solutions into Nanofibers: Rheology and Morphology Relationships

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2014年第6期32卷 793-804页

作者： ali Abbasi Mohamed Mahmoud Nasef Matsuura Takeshi reza Faridi-Majidi Faculty of Chemical Engineering Universiti Teknologi Malaysia Institute of Hydrogen Economy International Campus Universiti Teknologi Malaysia Malaysia-Japan International Institute of Technology International Campus Universiti Teknologi Malaysia Department of Chemical & Biological Engineering University Ottawa Department of Medical Nanotechnology School of Advanced Medical Technologies Tehran University of Medical Sciences

The relationship between the rheological properties of nylon-6,6 solutions and the morphology of their electrospun nanofibers was established. The viscosity of nylon-6,6 in formic acid （90%） was measured in the concentration range of 5 wt%-25 wt% using a programmable viscometer. Electrospinning of nylon-6,6 solutions was carried out under controlled parameters. The chemical structure, morphology and thermal properties of the obtained nanofibers were investigated using Fourier transform infrared spectroscopy （FTIR）, scanning electron microscopy （SEM） and differential scanning calorimetry （DSC）, respectively, Entanglement concentration （ce） was found to be 15 wt% and a power law relationship between specific viscosity and solution concentration was observed with exponents of 2.0 and 3.3 for semi-dilute unentangled （c 〈 ce） and semi-dilute entangled （c 〉 ce） regimes, respectively. The diameter and uniformity of the nanofibers were found to be dependent on the viscosity. Moreover, the average diameter of electrospun nanofibers was found to be dependent on zero shear rate viscosity and normalized concentration （c/ce） in a power law relationship with exponents of 0.298 and 0.816, respectively. For nylon-6,6 solutions, the entanglement concentration （ce = 15 wt%） provides the threshold viscosity required for the formation of a stable polymeric jet during electrospinning and producing uniform beadless fibers. For concentrations less than ce, beaded fibers with some irregularities are formed. DSC analysis showed an increase in crystallinity of all electrospun samples compared to original polymer. Furthermore; Based on FTIR spectroscopy, α phase is dominant in electrospun nanofibers and minor amount offland ）,phases is also available.

关键词： Nylon-6,6 electrospinning Viscosity Nanofibers Entanglement concentration Crystallinity.

Synthesis and Crystal Structure of N-(2-(1,3,4-oxadiazol-2-yl)phenyl)-2,3-dimethylaniline

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2014年第3期33卷 407-414页

作者： ali Souldozi Seyed Hamid reza Shojaei ali Ramazani Katarzyna ?lepokura Tadeusz Lis Department of Chemistry Urmia Branch Islamic Azad University Department of Physics Urmia Branch Islamic Azad University Department of Chemistry Zanjan Branch Islamic Azad University Faculty of Chemistry University of Wroc?aw 14 Joliot-Curie St. 50-383 Wroc?aw Poland

The title compound, N-（2-（1,3,4-oxadiazol-2-yl）phenyl）-2,3-dimethylaniline, was synthesized and studied by single-crystal X-ray diffraction method. The structure of the product was confirmed by IR, ^1H- and ^13C-NMR spectroscopy, elemental analysis and mass spectrometry. These experimental studies were supported by theoretical optimizations.

关键词： single-crystal X-ray structure 1,3,4-oxadiazoles N-(2-(1,3,4-oxadiazol-2- yl)phenyl)-2,3-dimethylaniline (N-isocyanimino)triphenylphosphorane

Synthesis and Crystal Structure of Methyl 2-(Diphenylamino)-4-phenyl-1,3-thiazole-5-carboxylate

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2013年第1期32卷 82-88页

作者： ali Souldozi Seyed Hamid reza Shojaei ali Ramazani Katarzyna lepokura Tadeusz Lis Department of Chemistry Urmia Branch Islamic Azad University P. O. Box 969 Urmia Iran Department of Physics Urmia Branch Islamic Azad University P. O. Box 969 Urmia Iran Department of Chemistry Zanjan Branch Islamic Azad University P. O. Box 49195-467 Zanjan Iran Faculty of Chemistry University of Wroclaw 14 Joliot-Curie St. 50-383 Wroclaw Poland

The title compound, methyl 2-（diphenylamino）-4-phenyl-1,3-thiazole-5-carboxylate, was synthesized and studied by single-crystal X-ray diffraction method. The structure of the product was confirmed by IR, 1H- and 13C-NMR spectroscopy and elemental analysis. These experimental studies were supported by quantum mechanical calculations. The structure was solved in monoclinic, space group P21/c with a = 9.573（3）, b = 19.533（7）, c = 9.876（3）, β = 92.35（4）°, V = 1845.2（10）3, T = 85（2） K, Z = 4, R = 0.040 and wR = 0.089 for 6424 observed reflections with I2σ（I）.

关键词： single-crystal X-ray structure multi-component reaction methyl 2-(diphenylamino)-4-phenyl-1 3-thiazole-5-carboxylate benzoyl isothiocyanate diphenylamine dimethyl acetylenedicarboxylate

Effects of chelating agents on the sol-gel synthesis of nano-zirconia:Comparison of the Pechini and sugar-based methods

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2020年第5期27卷 693-702页

作者： Faramarz Kazemi Farzin Arianpour Mahdiar Taheri ali Saberi Hamid reza rezaie Department of Mining and Metallurgy Amirkabir University of TechnologyTehranIran Research and Application Center Kastamonu UniversityKastamonuTurkey College of Engineering and Computer Science The Australian National UniversityCanberraAustralia Materials Processing Faculty of Engineering ScienceUniversity of BayreuthBayreuthGermany School of Metallurgy and Materials Engineering Iran University of Science and TechnologyTehranIran

This study focused on the comparison of the Pechini and sugar-based combustion synthesis methods to produce nano-zirconia. Zirconium hydroxide was utilized as metal precursor and citric acid, sucrose, and fructose were used as chelating agents, followed by calcination at 500, 600, and 700°C in air, respectively. Characterization was conducted by thermal analysis, specific surface area measurement, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning and transmission electron microscopy. When sucrose and citric acid were used as chelating agents during synthesis, mixtures of monoclinic and tetragonal phases were formed after calcination at 600 and 700°C. In the fructose samples, the tetragonal structure was the unique characterized phase. The tetragonal parameters in the fructose samples were determined using the diffraction data and the lattice parameter ratio was proven to increase with the temperature increase. Compared with the citrate and sucrose samples, the largest specific surface area(27 m2·g-1) and smallest particle size(39.1 nm) were obtained for the fructose sample after calcination at 700°C. The study revealed the formation of single-phase stabilized tetragonal zirconia using fructose as chelating agent after calcination at 500°C, and the presence and formation mechanism of stabilized tetragonal phase were also discussed on the basis of the X-ray and electron diffraction studies.

关键词： zirconia nanopowder sol-gel sugar Pechini chelation

Zinc chloride catalyzed synthesis of 5-substituted 1H-tetrazoles under solvent free condition

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2009年第11期20卷 1311-1314页

作者： Shahnaz Rostamizadeh Hamid Ghaieni reza Aryan ali Amani Department of Chemistry Faculty of SciencesK.N.Toosi University of TechnologyP.O.Box:15875-4416TehranIran Faculty of Material and Chemical Engineering Malek Ashtar University of TechnologyTehranIran Department of Chemistry Faculty of SciencesK.N.Toosi University of Technology P.O.Box:15875-4416TehranIran

Zinc chloride is an efficient and safe catalyst in the [3 ＋ 2] cycloaddition reaction of organic nitriles with sodium azide in solventless condition. The corresponding 5-substituted ^1H tetrazoles were obtained under mild conditions. This method can overcome disadvantages such as： the use of toxic metals and expensive reagents, drastic reaction conditions, water sensitivity and the presence of dangerous hydrazoic acid.

关键词： 5-Substituted ^1H-tetrazoles Zinc chloride Sodium azide Solvent free

An efficient method for synthesis of acylals from aldehydes using multi-walled carbon nanotubes functionalized with phosphonic acid(MWCNTs-C-PO_3H_2)

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2014年第12期25卷 1630-1634页

作者： Farzaneh Dehghani ali reza Sardarian Mohammad Mehdi Doroodmand Chemistry Department College of SciencesShiraz University Nanotechnology Research Center Shiraz University

MWCNTs-C-PO3H2has been used as an efficient,heterogeneous and reusable nanocatalyst for synthesis of acylals from aldehydes under solvent-free conditions at room temperature.A wide range of aldehydes was studied and corresponding products were obtained in good to excellent yields in short reaction *** can be easily recovered by centrifuge and reused for subsequent reactions for at least five times without deterioration in catalytic *** major advantages of the present method are high yields,short reaction time,recyclable catalyst and solvent-free reaction conditions at room temperature.

关键词： Acylal MWCNTs-C-PO_3H_2 Heterogeneous catalyst Reusable catalyst Solvent-free condition

Regioselective tetrahydropyranylation of alcohols catalyzed by Fe(HSO_4)_3

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2007年第7期18卷 803-806页

作者： Farhad Shirini Mohammad ali Zolfigol Abdol-reza Abri Department of Chemistry College of Science The University of Guilan Rasht 41335 Iran Department of Chemistry College of Science Bu-Ali Sina University Hamadan 65174 Iran

Alcohols are selectively and efficiently protected as their tetrahydropranyl ethers in the presence of a catalytic amount of Fe（HSO4）3 in good to high yields. All reactions are performed under mild and completely he... 详细信息

关键词： Alcohols Tetrahydropyranylation Tetrahydropyranyl ethers Fe(HSO4)3 Heterogeneous reaction conditions