Documents disponibles écrits par cet auteur

Density functional theory study of methane oxidation and reforming on Pt(111) and Pt(211) / Ying Chen in Industrial & engineering chemistry research, Vol. 51 N° 38 (Septembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12244–12252 Titre : Density functional theory study of methane oxidation and reforming on Pt(111) and Pt(211) Type de document : texte imprimé Auteurs : Ying Chen, Auteur ; Dionisios G. Vlachos, Auteur Année de publication : 2012 Article en page(s) : pp. 12244–12252 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Methane  Oxidation Résumé : The activation barriers of elementary-like reactions pertaining to the oxidation and reforming of methane on Pt(111) and Pt(211) surfaces have been calculated using periodic density functional theory (DFT) calculations. We have investigated the adsorption of CHx(x=1–3)OH and CHx(x=1–3)O, all the O and OH-assisted dehydrogenation reactions of CHx(x=1–4), all the C–O bond coupling reactions forming C1 oxygenates, and their subsequent dehydrogenation. It has been found that (i) COH and CHO are the most stable C1 oxygenates on Pt(111) and Pt(211), repectively; (ii) In the presence of O on Pt(211), oxidative dehydrogenation of CH by O is more kinetically favorable than the pyrolytic CH dehydrogenation; (iii) CO can be generated by oxidation of C with a low reaction barrier on Pt(211); (iv) The reactions involving OH and the dehydrogenation of CHx(x=1–3)OH and CHx(x=1–3)O appear to be secondary reaction pathways on Pt. Based on the activation barriers, we conclude that the major reaction pathways on Pt(111) and Pt(211) are CH4 (g) → CH3ad → CH2ad → CHad → Cad, Cad + Oad → COad and CH4 (g) → CH3ad → CH2ad → CHad, CHad + Oad → Cad, CHad + Oad → COad, respectively. Low coordination sites, such as steps, exhibit lower barriers for pyrolytic dehydrogenation except for the reaction CH2ad + * → CHad + Had that is preferred on terraces. In addition, they are lower barrier sites in the oxidation of C and CH and, thus, are expected to play a key role in partial and total oxidation of methane. In methane steam reforming, OHad may play a role only in the last step of C oxidation and certainly in the water-gas shift reaction, and, thus, this process consists of nearly decoupled methane catalytic pyrolysis and water-gas shift reactions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301792g [article] Density functional theory study of methane oxidation and reforming on Pt(111) and Pt(211) [texte imprimé] / Ying Chen, Auteur ; Dionisios G. Vlachos, Auteur . - 2012 . - pp. 12244–12252. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12244–12252 Mots-clés : Methane  Oxidation Résumé : The activation barriers of elementary-like reactions pertaining to the oxidation and reforming of methane on Pt(111) and Pt(211) surfaces have been calculated using periodic density functional theory (DFT) calculations. We have investigated the adsorption of CHx(x=1–3)OH and CHx(x=1–3)O, all the O and OH-assisted dehydrogenation reactions of CHx(x=1–4), all the C–O bond coupling reactions forming C1 oxygenates, and their subsequent dehydrogenation. It has been found that (i) COH and CHO are the most stable C1 oxygenates on Pt(111) and Pt(211), repectively; (ii) In the presence of O on Pt(211), oxidative dehydrogenation of CH by O is more kinetically favorable than the pyrolytic CH dehydrogenation; (iii) CO can be generated by oxidation of C with a low reaction barrier on Pt(211); (iv) The reactions involving OH and the dehydrogenation of CHx(x=1–3)OH and CHx(x=1–3)O appear to be secondary reaction pathways on Pt. Based on the activation barriers, we conclude that the major reaction pathways on Pt(111) and Pt(211) are CH4 (g) → CH3ad → CH2ad → CHad → Cad, Cad + Oad → COad and CH4 (g) → CH3ad → CH2ad → CHad, CHad + Oad → Cad, CHad + Oad → COad, respectively. Low coordination sites, such as steps, exhibit lower barriers for pyrolytic dehydrogenation except for the reaction CH2ad + * → CHad + Had that is preferred on terraces. In addition, they are lower barrier sites in the oxidation of C and CH and, thus, are expected to play a key role in partial and total oxidation of methane. In methane steam reforming, OHad may play a role only in the last step of C oxidation and certainly in the water-gas shift reaction, and, thus, this process consists of nearly decoupled methane catalytic pyrolysis and water-gas shift reactions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301792g

Elastic analysis of beam-wall joints subjected to out-of-plane bending / Ying Chen in Journal of structural engineering, Vol. 138 N° 6 (Juin 2012) 

Public ISBD [article]  in Journal of structural engineering > Vol. 138 N° 6 (Juin 2012) . - pp. 718–728 Titre : Elastic analysis of beam-wall joints subjected to out-of-plane bending Type de document : texte imprimé Auteurs : Ying Chen, Auteur ; Zhifei Shi, Auteur ; Yilung Mo, Auteur Année de publication : 2012 Article en page(s) : pp. 718–728 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Beam-wall  joint  Nonplanar  bending  Plate  theory  Equivalent  bending  width Résumé : The mechanical performance of reinforced concrete beam-thin-wall joints under out-of-plane bending moments is studied and the analytical solutions in terms of stresses and rotational stiffness of the wall are obtained. For convenience, the equivalent bending width of the shear walls is introduced and obtained based on two equivalence principles. A detailed parametric study of the equivalent bending width is carried out, including geometric parameters, boundary conditions, and reinforcement ratio of the beam-wall joint in shear wall. Some simplified formulae for the equivalent width are proposed and compared with both the analytical solutions and the experimental results. Good agreements are found. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000519 [article] Elastic analysis of beam-wall joints subjected to out-of-plane bending [texte imprimé] / Ying Chen, Auteur ; Zhifei Shi, Auteur ; Yilung Mo, Auteur . - 2012 . - pp. 718–728. Génie Civil Langues : Anglais (eng) in Journal of structural engineering > Vol. 138 N° 6 (Juin 2012) . - pp. 718–728 Mots-clés : Beam-wall  joint  Nonplanar  bending  Plate  theory  Equivalent  bending  width Résumé : The mechanical performance of reinforced concrete beam-thin-wall joints under out-of-plane bending moments is studied and the analytical solutions in terms of stresses and rotational stiffness of the wall are obtained. For convenience, the equivalent bending width of the shear walls is introduced and obtained based on two equivalence principles. A detailed parametric study of the equivalent bending width is carried out, including geometric parameters, boundary conditions, and reinforcement ratio of the beam-wall joint in shear wall. Some simplified formulae for the equivalent width are proposed and compared with both the analytical solutions and the experimental results. Good agreements are found. ISSN : 0733-9445 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29ST.1943-541X.0000519

Investigation on the spherical crystallization process of cefotaxime sodium / Haitao Zhang in Industrial & engineering chemistry research, Vol. 49 N° 3 (Fevrier 2010)

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1402–1411 Titre : Investigation on the spherical crystallization process of cefotaxime sodium Type de document : texte imprimé Auteurs : Haitao Zhang, Auteur ; Ying Chen, Auteur ; Jingkang Wang, Auteur Année de publication : 2010 Article en page(s) : pp. 1402–1411 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Investigation  on  the  Spherical  Crystallization  Process  of  Cefotaxime  Sodium Résumé : In order to obtain satisfied spherical agglomerated product and overcome the incomplete removal of the impurity during the traditional spherical agglomerated process, a new strategy incorporating the spherical agglomeration technique and the drowning-out crystallization process, by which the impurities can be efficiently removed, was performed. A triangular phase diagram showing the phase equilibrium of ternary solvent mixtures used in the process of spherical crystallization was constructed and the real-time spherical crystallization process was investigated by means of particle vision measurement and microscopy. The operation conditions, including the chloroform content, temperature of the system, and agitation speed, were also investigated in order to optimize the spherical crystallization process. The results of HPLC and GC indicated that the purity and residual solvents of the experimental agglomerated product can meet the requirements for use. Simultaneously, their bulk density, flowability, and compressibility are far better than the dispersed crystals. The agglomerated particle size was easily controlled by adjusting the chloroform content, temperature of the system, and agitation during spherical crystallization. Especially, the chloroform content is much more important than temperature and agitation in determining agglomerated particle size. ISSN : 0888-5885 [article] Investigation on the spherical crystallization process of cefotaxime sodium [texte imprimé] / Haitao Zhang, Auteur ; Ying Chen, Auteur ; Jingkang Wang, Auteur . - 2010 . - pp. 1402–1411. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1402–1411 Mots-clés : Investigation  on  the  Spherical  Crystallization  Process  of  Cefotaxime  Sodium Résumé : In order to obtain satisfied spherical agglomerated product and overcome the incomplete removal of the impurity during the traditional spherical agglomerated process, a new strategy incorporating the spherical agglomeration technique and the drowning-out crystallization process, by which the impurities can be efficiently removed, was performed. A triangular phase diagram showing the phase equilibrium of ternary solvent mixtures used in the process of spherical crystallization was constructed and the real-time spherical crystallization process was investigated by means of particle vision measurement and microscopy. The operation conditions, including the chloroform content, temperature of the system, and agitation speed, were also investigated in order to optimize the spherical crystallization process. The results of HPLC and GC indicated that the purity and residual solvents of the experimental agglomerated product can meet the requirements for use. Simultaneously, their bulk density, flowability, and compressibility are far better than the dispersed crystals. The agglomerated particle size was easily controlled by adjusting the chloroform content, temperature of the system, and agitation during spherical crystallization. Especially, the chloroform content is much more important than temperature and agitation in determining agglomerated particle size. ISSN : 0888-5885