Documents disponibles écrits par cet auteur

Dynamic behaviour and visco-elastic damage model of ultra-high performance cementitious composite / Jianzhong Lai in Cement and concrete research, Vol. 39 N° 11 (Novembre 2009) 

Public ISBD [article]  in Cement and concrete research > Vol. 39 N° 11 (Novembre 2009) . - pp. 1044–1051 Titre : Dynamic behaviour and visco-elastic damage model of ultra-high performance cementitious composite Type de document : texte imprimé Auteurs : Jianzhong Lai, Auteur ; Wei Sun, Auteur Année de publication : 2010 Article en page(s) : pp. 1044–1051 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Cement  composite;  Mechanical  properties;  Fiber  reinforcement;  Modeling Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : The dynamic behaviour of ultra-high performance cementitious composite (UHPCC) with compressive strength of 200 MPa with different steel fiber volume fractions was studied under impact using the split Hopkinson pressure bar. Three aspects of the testing: a gimbal device, wave shaping and direct strain measurement, were used to increase experimental accuracy. Results indicate that UHPCC has obvious strain rate effects. The peak stress, peak strain, elastic modulus and the area under the stress–strain curve increase with increasing strain rate. When the strain rate exceeds a threshold value, specimens with and without fibers begin to fracture. At high strain rate the unreinforced specimens fracture into small parts while fiber reinforced ones only have fine cracks on the edges. A visco-elastic damage model of UHPCC is proposed based on a nonlinear visco-elastic model (the ZWT model) and the material damage measured by the ultrasonic wave velocity method. DEWEY : 620.13 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609001720 [article] Dynamic behaviour and visco-elastic damage model of ultra-high performance cementitious composite [texte imprimé] / Jianzhong Lai, Auteur ; Wei Sun, Auteur . - 2010 . - pp. 1044–1051. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 39 N° 11 (Novembre 2009) . - pp. 1044–1051 Mots-clés : Cement  composite;  Mechanical  properties;  Fiber  reinforcement;  Modeling Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : The dynamic behaviour of ultra-high performance cementitious composite (UHPCC) with compressive strength of 200 MPa with different steel fiber volume fractions was studied under impact using the split Hopkinson pressure bar. Three aspects of the testing: a gimbal device, wave shaping and direct strain measurement, were used to increase experimental accuracy. Results indicate that UHPCC has obvious strain rate effects. The peak stress, peak strain, elastic modulus and the area under the stress–strain curve increase with increasing strain rate. When the strain rate exceeds a threshold value, specimens with and without fibers begin to fracture. At high strain rate the unreinforced specimens fracture into small parts while fiber reinforced ones only have fine cracks on the edges. A visco-elastic damage model of UHPCC is proposed based on a nonlinear visco-elastic model (the ZWT model) and the material damage measured by the ultrasonic wave velocity method. DEWEY : 620.13 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609001720

New collectors for the flotation of unactivated marmatite / Run-qing Liu in Minerals engineering, Vol. 23 N° 2 (Janvier 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 2 (Janvier 2010) . - pp. 99-103 Titre : New collectors for the flotation of unactivated marmatite Type de document : texte imprimé Auteurs : Run-qing Liu, Auteur ; Wei Sun, Auteur ; Yue-hua Hu, Auteur Article en page(s) : pp. 99-103 Note générale : Génie Minier Métallurgie Langues : Anglais (eng) Mots-clés : Sulfide  ores  Froth  flotation  Flotation  collectors Index. décimale : 622 Industrie minière Résumé : Three thiophenol collectors were tested for the flotation of marmatite without activation by copper sulfate. Flotation tests showed that marmatite flotation increased according to the following order: 2-fluoro thiophenol < 2-hydroxy thiophenol < 2-amino thiophenol. All these thiophenols exhibited a better flotation property for marmatite than butyl xanthate. Infrared spectra indicated that 2-amino thiophenol and 2-hydroxy thiophenol chemically adsorbed onto the surface of marmatite. 2-Fluoro thiophenol adsorbed physically onto the surface of marmatite. Quantum chemical calculations indicated that the energy of the highest occupied molecular orbital (HOMO) for 2-amino thiophenol was the highest among the tested collectors and we thus determined that its collecting ability should be the strongest. This agreed with the experimentally determined flotation results. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VDR-4XDKC9K-1&_user=6 [...] [article] New collectors for the flotation of unactivated marmatite [texte imprimé] / Run-qing Liu, Auteur ; Wei Sun, Auteur ; Yue-hua Hu, Auteur . - pp. 99-103. Génie Minier Métallurgie Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 2 (Janvier 2010) . - pp. 99-103 Mots-clés : Sulfide  ores  Froth  flotation  Flotation  collectors Index. décimale : 622 Industrie minière Résumé : Three thiophenol collectors were tested for the flotation of marmatite without activation by copper sulfate. Flotation tests showed that marmatite flotation increased according to the following order: 2-fluoro thiophenol < 2-hydroxy thiophenol < 2-amino thiophenol. All these thiophenols exhibited a better flotation property for marmatite than butyl xanthate. Infrared spectra indicated that 2-amino thiophenol and 2-hydroxy thiophenol chemically adsorbed onto the surface of marmatite. 2-Fluoro thiophenol adsorbed physically onto the surface of marmatite. Quantum chemical calculations indicated that the energy of the highest occupied molecular orbital (HOMO) for 2-amino thiophenol was the highest among the tested collectors and we thus determined that its collecting ability should be the strongest. This agreed with the experimentally determined flotation results. DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6VDR-4XDKC9K-1&_user=6 [...]

Preparation of hydrolyzate of hogwash oil (HHO) and its application in separating diaspore from kaolinite / Wei Sun in Minerals engineering, Vol. 23 N° 9 (Août 2010) 

Public ISBD [article]  in Minerals engineering > Vol. 23 N° 9 (Août 2010) . - pp. 670–675 Titre : Preparation of hydrolyzate of hogwash oil (HHO) and its application in separating diaspore from kaolinite Type de document : texte imprimé Auteurs : Wei Sun, Auteur ; Kui Ouyang, Auteur ; Limin Zhang, Auteur Année de publication : 2011 Article en page(s) : pp. 670–675 Note générale : Génie Minier Langues : Anglais (eng) Mots-clés : Recycling  Flotation  collectors  Oxide  ores  Mineral  processing Résumé : Hydrolyzate of hogwash oil (HHO) was prepared at ambient pressure using hogwash oil that was collected from the dietary industry as a raw material by means of non-pressurized multistage hydrolyzation. Before hydrolyzation, the collected hogwash oil was subject to pre-treatment that included deposition edulcoration, acidification degumming and deodorization by digestion as well as vacuum dewatering. Components of the synthesized products were detected by gas chromatography and the results indicated that unsaturated fatty acids are the major components. Using HHO as a collector, the flotation behavior of diaspore and kaolinite was investigated. The reaction mechanisms of diaspore and kaolinite with HHO are discussed based on a zeta potential test. The results showed that a concentrate with a mass ratio of Al2O3 to SiO2 of 14.42 and an Al2O3 recovery of 81.80% can be obtained at a feed mass ratio of Al2O3 to SiO2 of 5. This indicated that the HHO is a potential collector for separating diaspore from aluminosilicate minerals in bauxite. The results also suggested a possible way to reuse discarded hogwash oil to avoid environmental pollutio DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000907 [article] Preparation of hydrolyzate of hogwash oil (HHO) and its application in separating diaspore from kaolinite [texte imprimé] / Wei Sun, Auteur ; Kui Ouyang, Auteur ; Limin Zhang, Auteur . - 2011 . - pp. 670–675. Génie Minier Langues : Anglais (eng) in Minerals engineering > Vol. 23 N° 9 (Août 2010) . - pp. 670–675 Mots-clés : Recycling  Flotation  collectors  Oxide  ores  Mineral  processing Résumé : Hydrolyzate of hogwash oil (HHO) was prepared at ambient pressure using hogwash oil that was collected from the dietary industry as a raw material by means of non-pressurized multistage hydrolyzation. Before hydrolyzation, the collected hogwash oil was subject to pre-treatment that included deposition edulcoration, acidification degumming and deodorization by digestion as well as vacuum dewatering. Components of the synthesized products were detected by gas chromatography and the results indicated that unsaturated fatty acids are the major components. Using HHO as a collector, the flotation behavior of diaspore and kaolinite was investigated. The reaction mechanisms of diaspore and kaolinite with HHO are discussed based on a zeta potential test. The results showed that a concentrate with a mass ratio of Al2O3 to SiO2 of 14.42 and an Al2O3 recovery of 81.80% can be obtained at a feed mass ratio of Al2O3 to SiO2 of 5. This indicated that the HHO is a potential collector for separating diaspore from aluminosilicate minerals in bauxite. The results also suggested a possible way to reuse discarded hogwash oil to avoid environmental pollutio DEWEY : 622 ISSN : 0892-6875 En ligne : http://www.sciencedirect.com/science/article/pii/S0892687510000907

RBF Networks-based adaptive inverse model control system for electronic throttle / Yuan Xiaofang in IEEE Transactions on control systems technology, Vol. 18 N° 3 (Mai 2010) 

Public ISBD [article]  in IEEE Transactions on control systems technology > Vol. 18 N° 3 (Mai 2010) . - pp. 750-756 Titre : RBF Networks-based adaptive inverse model control system for electronic throttle Type de document : texte imprimé Auteurs : Yuan Xiaofang, Auteur ; Wang Yaonan, Auteur ; Wei Sun, Auteur Année de publication : 2011 Article en page(s) : pp. 750-756 Note générale : Génie Aérospatial Langues : Anglais (eng) Mots-clés : Back-propagation  Electronic  throttle  Inverse  model  control  Model  identification  Neural  networks Index. décimale : 629.1 Résumé : An electronic throttle is a dc-motor-driven valve that regulates air inflow into the combustion system of the engine. An effective controller for electronic throttle is not easy to accomplish since the plant is burdened with strong nonlinear effects of stick-slip friction, spring, and gear backlash. In this brief, an adaptive inverse model control system (AIMCS) is designed for the plant, and two radial basis function (RBF) neural networks are utilized in the AIMCS. The plant is identified by a RBF networks identifier, which provides the sensitivity information of the plant to the control input. And another RBF networks is utilized as inverse model controller established by inverse system method. The RBF networks are offline learned firstly and are online trained using back propagation algorithms. To guarantee convergence and for faster learning, adaptive learning rates are developed. Simulation and experiment results show the effectiveness of the AIMCS. DEWEY : 629.1 ISSN : 1063-6536 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5256140 [article] RBF Networks-based adaptive inverse model control system for electronic throttle [texte imprimé] / Yuan Xiaofang, Auteur ; Wang Yaonan, Auteur ; Wei Sun, Auteur . - 2011 . - pp. 750-756. Génie Aérospatial Langues : Anglais (eng) in IEEE Transactions on control systems technology > Vol. 18 N° 3 (Mai 2010) . - pp. 750-756 Mots-clés : Back-propagation  Electronic  throttle  Inverse  model  control  Model  identification  Neural  networks Index. décimale : 629.1 Résumé : An electronic throttle is a dc-motor-driven valve that regulates air inflow into the combustion system of the engine. An effective controller for electronic throttle is not easy to accomplish since the plant is burdened with strong nonlinear effects of stick-slip friction, spring, and gear backlash. In this brief, an adaptive inverse model control system (AIMCS) is designed for the plant, and two radial basis function (RBF) neural networks are utilized in the AIMCS. The plant is identified by a RBF networks identifier, which provides the sensitivity information of the plant to the control input. And another RBF networks is utilized as inverse model controller established by inverse system method. The RBF networks are offline learned firstly and are online trained using back propagation algorithms. To guarantee convergence and for faster learning, adaptive learning rates are developed. Simulation and experiment results show the effectiveness of the AIMCS. DEWEY : 629.1 ISSN : 1063-6536 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5256140

Selective flotation of chalcopyrite and marmatite by MBT and electrochemical analysis / Wenqing Qin in Industrial & engineering chemistry research, Vol. 51 N° 35 (Septembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 35 (Septembre 2012) . - pp. 11538-11546 Titre : Selective flotation of chalcopyrite and marmatite by MBT and electrochemical analysis Type de document : texte imprimé Auteurs : Wenqing Qin, Auteur ; Fen Jiao, Auteur ; Wei Sun, Auteur Année de publication : 2012 Article en page(s) : pp. 11538-11546 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Flotation Résumé : Various collectors were compared in the selective flotation of copper-zinc ore by using isopropyl ethylthionocarbamate (Z-200), buthl xanthate, ammonium dibutyl dithiophosphate, and mercapto benzothiazole (MBT). The latter showed effective selectivity in the flotation of chalcopyrite and marmatite and was selected for a detailed study by using cyclic voltammetry and Tafel. The results of microflotation pointed out that the flotation of marmatite was significantly affected by CuSO4 activation. At weakly alkaline pH, marmatite activated by Cu2+ is dependent on Cu2+ concentration shown in electrochemical tests, and the activation products were Cu2S and CuS. The increasing addition of Cu2+ may remove the hydroxide and S0, resulting in considerable activation. The corrosion of marmatite is accelerated with the addition of CuSO4. Mechanisms are suggested for the selectivity of chalcopyrite/marmatite by MBT: the hydrophilic hydroxides (Zn(OH)2 and Fe(OH)3) are formed on the marmatite surface, which renders the marmatite surface hydrophilic and hampers the reaction between MBT and marmatite-activated products, while the hydrophobic compounds (MBT)2 and Cu(MBT)2 formed on the chalcopyrite surface improve the flotability of chalcopyrite. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26324803 [article] Selective flotation of chalcopyrite and marmatite by MBT and electrochemical analysis [texte imprimé] / Wenqing Qin, Auteur ; Fen Jiao, Auteur ; Wei Sun, Auteur . - 2012 . - pp. 11538-11546. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 35 (Septembre 2012) . - pp. 11538-11546 Mots-clés : Flotation Résumé : Various collectors were compared in the selective flotation of copper-zinc ore by using isopropyl ethylthionocarbamate (Z-200), buthl xanthate, ammonium dibutyl dithiophosphate, and mercapto benzothiazole (MBT). The latter showed effective selectivity in the flotation of chalcopyrite and marmatite and was selected for a detailed study by using cyclic voltammetry and Tafel. The results of microflotation pointed out that the flotation of marmatite was significantly affected by CuSO4 activation. At weakly alkaline pH, marmatite activated by Cu2+ is dependent on Cu2+ concentration shown in electrochemical tests, and the activation products were Cu2S and CuS. The increasing addition of Cu2+ may remove the hydroxide and S0, resulting in considerable activation. The corrosion of marmatite is accelerated with the addition of CuSO4. Mechanisms are suggested for the selectivity of chalcopyrite/marmatite by MBT: the hydrophilic hydroxides (Zn(OH)2 and Fe(OH)3) are formed on the marmatite surface, which renders the marmatite surface hydrophilic and hampers the reaction between MBT and marmatite-activated products, while the hydrophobic compounds (MBT)2 and Cu(MBT)2 formed on the chalcopyrite surface improve the flotability of chalcopyrite. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26324803

Study of ion cluster reorientation process of geopolymerisation reaction using semi-empirical AM1 calculations / Zhang Yunsheng in Cement and concrete research, Vol. 39 N° 12 (Décembre 2009) 

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Visible - light - induced heterostructured Zn – Al – In mixed metal oxide nanocomposite photocatalysts derived from a single precursor / Guoli Fan in Chemical engineering journal, Vol. 174 N° 1 (Octobre 2011) 

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