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Enhanced photocatalytic activity of ag3VO4 loaded with rare-earth elements under visible-light irradiation / Hui Xu in Industrial & engineering chemistry research, Vol. 48 N° 24 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10771–10778 Titre : Enhanced photocatalytic activity of ag3VO4 loaded with rare-earth elements under visible-light irradiation Type de document : texte imprimé Auteurs : Hui Xu, Auteur ; Huaming Li, Auteur ; Xu, Li, Auteur Année de publication : 2010 Article en page(s) : pp. 10771–10778 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Enhanced--Photocatalytic--Activity--Ag3VO4--Loaded--Rare-Earth  Elements--under--Visible-Light--Irradiation Résumé : Rare-earth-loaded Ag3VO4 catalysts (RE3+-Ag3VO4, RE = Nd, Sm, and Eu) were prepared by the wetness impregnation technique and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of the samples were evaluated by rhodamine B (RhB) dye degradation under visible-light irradiation. It was found that the presence of rare-earth oxides in the host Ag3VO4 could decrease the band gap and accelerate the separation of photogenerated electron−hole pairs, which led to higher photocatalytic activities. Among the rare-earth-loaded samples, Nd3+-loaded Ag3VO4 catalyst showed the highest photocatalytic activity. The optimum contents of Nd3+, Eu3+, and Sm3+ were found to be 2, 3, and 2 wt %, respectively. It was also found that the photocatalytic degradation of RhB over RE3+-Ag3VO4 (2 wt %) followed pseudo-first-order kinetics. A possible mechanism for RhB photocatalytic degradation over RE3+-Ag3VO4 catalysts is also proposed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900835g [article] Enhanced photocatalytic activity of ag3VO4 loaded with rare-earth elements under visible-light irradiation [texte imprimé] / Hui Xu, Auteur ; Huaming Li, Auteur ; Xu, Li, Auteur . - 2010 . - pp. 10771–10778. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10771–10778 Mots-clés : Enhanced--Photocatalytic--Activity--Ag3VO4--Loaded--Rare-Earth  Elements--under--Visible-Light--Irradiation Résumé : Rare-earth-loaded Ag3VO4 catalysts (RE3+-Ag3VO4, RE = Nd, Sm, and Eu) were prepared by the wetness impregnation technique and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of the samples were evaluated by rhodamine B (RhB) dye degradation under visible-light irradiation. It was found that the presence of rare-earth oxides in the host Ag3VO4 could decrease the band gap and accelerate the separation of photogenerated electron−hole pairs, which led to higher photocatalytic activities. Among the rare-earth-loaded samples, Nd3+-loaded Ag3VO4 catalyst showed the highest photocatalytic activity. The optimum contents of Nd3+, Eu3+, and Sm3+ were found to be 2, 3, and 2 wt %, respectively. It was also found that the photocatalytic degradation of RhB over RE3+-Ag3VO4 (2 wt %) followed pseudo-first-order kinetics. A possible mechanism for RhB photocatalytic degradation over RE3+-Ag3VO4 catalysts is also proposed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900835g

Enhanced photocatalytic activity of Ag3VO4 loaded with rare-earth elements under visible-light irradiation / Hui Xu in Industrial & engineering chemistry research, Vol. 48 N° 24 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10771–10778 Titre : Enhanced photocatalytic activity of Ag3VO4 loaded with rare-earth elements under visible-light irradiation Type de document : texte imprimé Auteurs : Hui Xu, Auteur ; Huaming Li, Auteur ; Xu, Li, Auteur Année de publication : 2010 Article en page(s) : pp. 10771–10778 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Rare-earth  element  Wetness  impregnation  technique  Photocatalytic  activities Résumé : Rare-earth-loaded Ag3VO4 catalysts (RE3+-Ag3VO4, RE = Nd, Sm, and Eu) were prepared by the wetness impregnation technique and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of the samples were evaluated by rhodamine B (RhB) dye degradation under visible-light irradiation. It was found that the presence of rare-earth oxides in the host Ag3VO4 could decrease the band gap and accelerate the separation of photogenerated electron−hole pairs, which led to higher photocatalytic activities. Among the rare-earth-loaded samples, Nd3+-loaded Ag3VO4 catalyst showed the highest photocatalytic activity. The optimum contents of Nd3+, Eu3+, and Sm3+ were found to be 2, 3, and 2 wt %, respectively. It was also found that the photocatalytic degradation of RhB over RE3+-Ag3VO4 (2 wt %) followed pseudo-first-order kinetics. A possible mechanism for RhB photocatalytic degradation over RE3+-Ag3VO4 catalysts is also proposed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900835g [article] Enhanced photocatalytic activity of Ag3VO4 loaded with rare-earth elements under visible-light irradiation [texte imprimé] / Hui Xu, Auteur ; Huaming Li, Auteur ; Xu, Li, Auteur . - 2010 . - pp. 10771–10778. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 24 (Décembre 2009) . - pp. 10771–10778 Mots-clés : Rare-earth  element  Wetness  impregnation  technique  Photocatalytic  activities Résumé : Rare-earth-loaded Ag3VO4 catalysts (RE3+-Ag3VO4, RE = Nd, Sm, and Eu) were prepared by the wetness impregnation technique and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activities of the samples were evaluated by rhodamine B (RhB) dye degradation under visible-light irradiation. It was found that the presence of rare-earth oxides in the host Ag3VO4 could decrease the band gap and accelerate the separation of photogenerated electron−hole pairs, which led to higher photocatalytic activities. Among the rare-earth-loaded samples, Nd3+-loaded Ag3VO4 catalyst showed the highest photocatalytic activity. The optimum contents of Nd3+, Eu3+, and Sm3+ were found to be 2, 3, and 2 wt %, respectively. It was also found that the photocatalytic degradation of RhB over RE3+-Ag3VO4 (2 wt %) followed pseudo-first-order kinetics. A possible mechanism for RhB photocatalytic degradation over RE3+-Ag3VO4 catalysts is also proposed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900835g

Output Feedback Adaptive Robust Control of Uncertain Linear Systems With Disturbances / Yao, Bin in Transactions of the ASME . Journal of dynamic systems, measurement, and control, Vol. 128 N°4 (Decembre 2006) 

Public ISBD [article]  in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 128 N°4 (Decembre 2006) . - 938-945 p. Titre : Output Feedback Adaptive Robust Control of Uncertain Linear Systems With Disturbances Titre original : Commande Robuste Adaptative de Rétroaction de Rendement des Systèmes Linéaires Incertains avec des Perturbations Type de document : texte imprimé Auteurs : Yao, Bin, Auteur ; Xu, Li, Auteur Article en page(s) : 938-945 p. Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Projection  discontinue  Arrangement  robuste  adaptif  Commande  de  rétroaction  Système  linéaire  Perturbation  paramétrique  Rétroaction  robuste Index. décimale : 629.8 Résumé : In this paper, a discontinuous projection based output feedback adaptive robust control (ARC) scheme is constructed for a class of linear systems subjected to both parametric uncertainties and disturbances that might be output dependent. An observer is first designed to provide exponentially convergent estimates of the unmeasured states. This observer has an extended filter structure so that on-line parameter adaptation can be utilized to reduce the effect of possible large disturbances that have known shapes but unknown amplitudes. Estimation errors that come from initial state estimates and uncompensated disturbances are dealt with via certain robust feedback at each step of the backstepping design. Compared to other existing output feedback robust adaptive control schemes, the proposed method explicitly takes into account the effect of disturbances and uses both parameter adaptation and robust feedback to attenuate their effects for an improved tracking performance. Experimental results on the control of an iron core linear motor are presented to illustrate the effectiveness and achievable performance of the proposed scheme. En cet article, une projection discontinue basée arrangement robuste adaptatif de commande de rétroaction de rendement (ARC) est construite pour une classe des systèmes linéaires soumis aux deux incertitudes et perturbations paramétriques qui pourraient être personne à charge produite. Un observateur est d'abord conçu pour fournir des évaluations exponentiellement convergentes des états immesurés. Cet observateur a une structure prolongée de filtre de sorte que l'adaptation en ligne de paramètre puisse être utilisée pour réduire l'effet des grandes perturbations possibles qui ont su des formes mais des amplitudes inconnues. Des erreurs d'évaluation qui viennent des évaluations d'état initial et des perturbations incompensées sont traitées par l'intermédiaire de certaine rétroaction robuste à chaque étape de la conception backstepping. Comparé à l'autre commande adaptative robuste de rétroaction existante de rendement complote, la méthode proposée tient compte explicitement de l'effet des perturbations et emploie l'adaptation de paramètre et la rétroaction robuste pour atténuer leurs effets pour une exécution de cheminement améliorée. Des résultats expérimentaux sur la commande d'un moteur linéaire de noyau de fer sont présentés pour illustrer l'efficacité et l'exécution réalisable de l'arrangement proposé. En ligne : byao@purdue.edu [article] Output Feedback Adaptive Robust Control of Uncertain Linear Systems With Disturbances = Commande Robuste Adaptative de Rétroaction de Rendement des Systèmes Linéaires Incertains avec des Perturbations [texte imprimé] / Yao, Bin, Auteur ; Xu, Li, Auteur . - 938-945 p. Génie Mécanique Langues : Anglais (eng) in Transactions of the ASME . Journal of dynamic systems, measurement, and control > Vol. 128 N°4 (Decembre 2006) . - 938-945 p. Mots-clés : Projection  discontinue  Arrangement  robuste  adaptif  Commande  de  rétroaction  Système  linéaire  Perturbation  paramétrique  Rétroaction  robuste Index. décimale : 629.8 Résumé : In this paper, a discontinuous projection based output feedback adaptive robust control (ARC) scheme is constructed for a class of linear systems subjected to both parametric uncertainties and disturbances that might be output dependent. An observer is first designed to provide exponentially convergent estimates of the unmeasured states. This observer has an extended filter structure so that on-line parameter adaptation can be utilized to reduce the effect of possible large disturbances that have known shapes but unknown amplitudes. Estimation errors that come from initial state estimates and uncompensated disturbances are dealt with via certain robust feedback at each step of the backstepping design. Compared to other existing output feedback robust adaptive control schemes, the proposed method explicitly takes into account the effect of disturbances and uses both parameter adaptation and robust feedback to attenuate their effects for an improved tracking performance. Experimental results on the control of an iron core linear motor are presented to illustrate the effectiveness and achievable performance of the proposed scheme. En cet article, une projection discontinue basée arrangement robuste adaptatif de commande de rétroaction de rendement (ARC) est construite pour une classe des systèmes linéaires soumis aux deux incertitudes et perturbations paramétriques qui pourraient être personne à charge produite. Un observateur est d'abord conçu pour fournir des évaluations exponentiellement convergentes des états immesurés. Cet observateur a une structure prolongée de filtre de sorte que l'adaptation en ligne de paramètre puisse être utilisée pour réduire l'effet des grandes perturbations possibles qui ont su des formes mais des amplitudes inconnues. Des erreurs d'évaluation qui viennent des évaluations d'état initial et des perturbations incompensées sont traitées par l'intermédiaire de certaine rétroaction robuste à chaque étape de la conception backstepping. Comparé à l'autre commande adaptative robuste de rétroaction existante de rendement complote, la méthode proposée tient compte explicitement de l'effet des perturbations et emploie l'adaptation de paramètre et la rétroaction robuste pour atténuer leurs effets pour une exécution de cheminement améliorée. Des résultats expérimentaux sur la commande d'un moteur linéaire de noyau de fer sont présentés pour illustrer l'efficacité et l'exécution réalisable de l'arrangement proposé. En ligne : byao@purdue.edu

Selective oxidation of cyclohexane over transition - metal - incorporated HMS in a solvent - free system / Jun Li in Industrial & engineering chemistry research, Vol. 49 N° 11 (Juin 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5392–5399 Titre : Selective oxidation of cyclohexane over transition - metal - incorporated HMS in a solvent - free system Type de document : texte imprimé Auteurs : Jun Li, Auteur ; Yong Shi, Auteur ; Xu, Li, Auteur Année de publication : 2010 Article en page(s) : pp. 5392–5399 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Cyclohexane  Oxidation Résumé : Mesostructure materials A-HMS (A = Ce, Ti, Co, Al, Cr, V, Zr) were synthesized with cetylamine as the structure director and tetraethyl orthosilicalite as the silica source. CeO2/V-HMS and CeO2/Al-HMS were prepared by dipping-calcination method. The materials were characterized by X-ray diffraction (XRD), UV−vis, Fourier transform infrared (FT-IR), N2 adsorption−desorption, inductively coupled plasma−atomic emission spectroscopy (ICP-AES), transmission electron microscopy (TEM), and 27Al magic angle spinning nuclear magnetic resonance (MAS NMR). The incorporated ions were mostly in the framework of the mesoporous materials, which were confirmed by the XRD, FT-IR, UV−vis, and 27Al MAS NMR analyses. The solids obtained were employed as heterogeneous catalysts for the selective oxidation of cyclohexane with oxygen (O2) as oxidant in a solvent-free system. The material CeO2/V-HMS exhibited the highest activity with about 18% conversion of cyclohexane but 68% total selectivity to cyclohexanol and cyclohexanone. The performance of Al(40)-HMS is satisfying for nearly 10% conversion of cyclohexane and 93% total selectivity to the desired products. Also, Al(40)-HMS is efficient for its excellent recyclable property in the oxidation of cyclohexane. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100092x [article] Selective oxidation of cyclohexane over transition - metal - incorporated HMS in a solvent - free system [texte imprimé] / Jun Li, Auteur ; Yong Shi, Auteur ; Xu, Li, Auteur . - 2010 . - pp. 5392–5399. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 11 (Juin 2010) . - pp. 5392–5399 Mots-clés : Cyclohexane  Oxidation Résumé : Mesostructure materials A-HMS (A = Ce, Ti, Co, Al, Cr, V, Zr) were synthesized with cetylamine as the structure director and tetraethyl orthosilicalite as the silica source. CeO2/V-HMS and CeO2/Al-HMS were prepared by dipping-calcination method. The materials were characterized by X-ray diffraction (XRD), UV−vis, Fourier transform infrared (FT-IR), N2 adsorption−desorption, inductively coupled plasma−atomic emission spectroscopy (ICP-AES), transmission electron microscopy (TEM), and 27Al magic angle spinning nuclear magnetic resonance (MAS NMR). The incorporated ions were mostly in the framework of the mesoporous materials, which were confirmed by the XRD, FT-IR, UV−vis, and 27Al MAS NMR analyses. The solids obtained were employed as heterogeneous catalysts for the selective oxidation of cyclohexane with oxygen (O2) as oxidant in a solvent-free system. The material CeO2/V-HMS exhibited the highest activity with about 18% conversion of cyclohexane but 68% total selectivity to cyclohexanol and cyclohexanone. The performance of Al(40)-HMS is satisfying for nearly 10% conversion of cyclohexane and 93% total selectivity to the desired products. Also, Al(40)-HMS is efficient for its excellent recyclable property in the oxidation of cyclohexane. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100092x