Documents disponibles écrits par cet auteur

Analysis of the essential oils of pine cones of pinus koraiensis steb. et zucc. and P. sylvestris L. from China / Yang, X. in The journal of essential oil research, Vol. 22 N° 5 (Septembre/Octobre 2010) 

Public ISBD [article]  in The journal of essential oil research > Vol. 22 N° 5 (Septembre/Octobre 2010) . - pp. 446-448 Titre : Analysis of the essential oils of pine cones of pinus koraiensis steb. et zucc. and P. sylvestris L. from China Type de document : texte imprimé Auteurs : Yang, X., Auteur ; H. Zhang, Auteur ; Y. Zhang, Auteur Année de publication : 2011 Article en page(s) : pp. 446-448 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Pinus  koraiensis  Pinus  sylvestris  Pinaceae  Essential  oil  composition  α-pinene  Limonene  Aaromadendrene  α-longipinene Index. décimale : 646 Résumé : The chemical composition of the essential oil obtained from pine cones of Pinus koraiensis and Pinus sylvestris from northeast China was analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS), and 35 and 31 components were identified, respectively. α-pinene (35.2%), limonene (18.4%), β-pinene (8.7%), β-caryophyllene (3.5%) and myrcene (3.0%) were the main components in P. koraiensis cone oil. Aromadendrene (20.2%), α-pinene (18.5%), α-longipinene (10.5%) and α-terpineol (5.5%) were the main components in P. sylvestris cone oil. The antioxidant activity of the oils from P. koraiensis and P. sylvestris was evaluated using the DPPH. DEWEY : 665 ISSN : 1041-2905 En ligne : http://www.tandfonline.com/doi/abs/10.1080/10412905.2010.9700368 [article] Analysis of the essential oils of pine cones of pinus koraiensis steb. et zucc. and P. sylvestris L. from China [texte imprimé] / Yang, X., Auteur ; H. Zhang, Auteur ; Y. Zhang, Auteur . - 2011 . - pp. 446-448. Génie Chimique Langues : Anglais (eng) in The journal of essential oil research > Vol. 22 N° 5 (Septembre/Octobre 2010) . - pp. 446-448 Mots-clés : Pinus  koraiensis  Pinus  sylvestris  Pinaceae  Essential  oil  composition  α-pinene  Limonene  Aaromadendrene  α-longipinene Index. décimale : 646 Résumé : The chemical composition of the essential oil obtained from pine cones of Pinus koraiensis and Pinus sylvestris from northeast China was analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS), and 35 and 31 components were identified, respectively. α-pinene (35.2%), limonene (18.4%), β-pinene (8.7%), β-caryophyllene (3.5%) and myrcene (3.0%) were the main components in P. koraiensis cone oil. Aromadendrene (20.2%), α-pinene (18.5%), α-longipinene (10.5%) and α-terpineol (5.5%) were the main components in P. sylvestris cone oil. The antioxidant activity of the oils from P. koraiensis and P. sylvestris was evaluated using the DPPH. DEWEY : 665 ISSN : 1041-2905 En ligne : http://www.tandfonline.com/doi/abs/10.1080/10412905.2010.9700368

A closer look at the local responses of twin and grain boundaries in Cu to stress at the nanoscale with possible transition from the P–H to the inverse P–H relation / L. Yue in Acta materialia, Vol. 58 N° 7 (Avril 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 7 (Avril 2010) . - pp. 2677–2684 Titre : A closer look at the local responses of twin and grain boundaries in Cu to stress at the nanoscale with possible transition from the P–H to the inverse P–H relation Type de document : texte imprimé Auteurs : L. Yue, Auteur ; H. Zhang, Auteur ; D.Y. Li, Auteur Année de publication : 2011 Article en page(s) : pp. 2677–2684 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Nano-twinning  Nano-grains  Inverse  Petch–Hall  relation  Molecular  dynamics  Simulation Résumé : Nanocrystalline copper is considered to be a candidate for electrical contacts for dynamic systems because of its intrinsic conductivity and enhanced fretting resistance. However, the enhanced electron scattering at high-density grain boundaries significantly deteriorates the overall conductivity of nanocrystalline copper. Recent studies suggest that nanosized twin boundaries in copper might be a solution to such a dilemma. To better understand the general mechanical behavior of nanotwin boundaries, we conducted molecular dynamics simulation studies to investigate responses of both nanotwin and nanograin boundaries in copper to stress at the nanoscale, particularly in the critical range of 5–25 nm where the inverse Petch–Hall relation (P–H) may occur in nanocrystalline copper. The obtained results suggest that the twin boundary blocks dislocation movement more effectively and the degree of emitting dislocations under stress is considerably lower than that of grain boundary, leading to superior mechanical behavior. The inverse P–H relation is not applicable to the nanotwinned system. It is also demonstrated that the inverse P–H relation occurring in nanograined materials does not necessarily result from grain boundary sliding. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410000029 [article] A closer look at the local responses of twin and grain boundaries in Cu to stress at the nanoscale with possible transition from the P–H to the inverse P–H relation [texte imprimé] / L. Yue, Auteur ; H. Zhang, Auteur ; D.Y. Li, Auteur . - 2011 . - pp. 2677–2684. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 7 (Avril 2010) . - pp. 2677–2684 Mots-clés : Nano-twinning  Nano-grains  Inverse  Petch–Hall  relation  Molecular  dynamics  Simulation Résumé : Nanocrystalline copper is considered to be a candidate for electrical contacts for dynamic systems because of its intrinsic conductivity and enhanced fretting resistance. However, the enhanced electron scattering at high-density grain boundaries significantly deteriorates the overall conductivity of nanocrystalline copper. Recent studies suggest that nanosized twin boundaries in copper might be a solution to such a dilemma. To better understand the general mechanical behavior of nanotwin boundaries, we conducted molecular dynamics simulation studies to investigate responses of both nanotwin and nanograin boundaries in copper to stress at the nanoscale, particularly in the critical range of 5–25 nm where the inverse Petch–Hall relation (P–H) may occur in nanocrystalline copper. The obtained results suggest that the twin boundary blocks dislocation movement more effectively and the degree of emitting dislocations under stress is considerably lower than that of grain boundary, leading to superior mechanical behavior. The inverse P–H relation is not applicable to the nanotwinned system. It is also demonstrated that the inverse P–H relation occurring in nanograined materials does not necessarily result from grain boundary sliding. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410000029

First-principles calculations of the elastic, phonon and thermodynamic properties of Al12Mg17 / H. Zhang in Acta materialia, Vol. 58 N° 11 (Juin 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 11 (Juin 2010) . - pp. 4012–4018 Titre : First-principles calculations of the elastic, phonon and thermodynamic properties of Al12Mg17 Type de document : texte imprimé Auteurs : H. Zhang, Auteur ; S.L. Shang, Auteur ; Y. Wang, Auteur Année de publication : 2011 Article en page(s) : pp. 4012–4018 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : First-principles  electron  theory  Intermetallic  compounds  Elastic  behavior  Thermodynamics Résumé : The elastic, phonon and thermodynamic properties of Al12Mg17 have been investigated by first-principles calculations. The obtained structural parameters, phonon dispersion curves and the predicted thermodynamic properties for all the phases studied herein agree well with available experimental data. The temperature-dependent single-crystal elastic constants are also predicted along with the polycrystalline aggregate properties, including bulk modulus, shear modulus, Young’s modulus, and Poisson’s ratio. The brittleness of Al12Mg17 that we predict is consistent with experiments, in contrast to the previous calculation showing ductile behavior. Detailed analysis of density of states further explains the present theoretical findings. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410001655 [article] First-principles calculations of the elastic, phonon and thermodynamic properties of Al12Mg17 [texte imprimé] / H. Zhang, Auteur ; S.L. Shang, Auteur ; Y. Wang, Auteur . - 2011 . - pp. 4012–4018. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 11 (Juin 2010) . - pp. 4012–4018 Mots-clés : First-principles  electron  theory  Intermetallic  compounds  Elastic  behavior  Thermodynamics Résumé : The elastic, phonon and thermodynamic properties of Al12Mg17 have been investigated by first-principles calculations. The obtained structural parameters, phonon dispersion curves and the predicted thermodynamic properties for all the phases studied herein agree well with available experimental data. The temperature-dependent single-crystal elastic constants are also predicted along with the polycrystalline aggregate properties, including bulk modulus, shear modulus, Young’s modulus, and Poisson’s ratio. The brittleness of Al12Mg17 that we predict is consistent with experiments, in contrast to the previous calculation showing ductile behavior. Detailed analysis of density of states further explains the present theoretical findings. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645410001655

Optimal multi-period service capacity allocation and pricing allowing for uncertain competitive entry / H. Zhang in Journal of the operational research society (JORS), Vol. 61 N° 5 (Mai 2010) 

Public ISBD [article]  in Journal of the operational research society (JORS) > Vol. 61 N° 5 (Mai 2010) . - pp. 780–789 Titre : Optimal multi-period service capacity allocation and pricing allowing for uncertain competitive entry Type de document : texte imprimé Auteurs : H. Zhang, Auteur ; H. I. Mesak, Auteur Année de publication : 2010 Article en page(s) : pp. 780–789 Note générale : Recherche opérationnelle Langues : Anglais (eng) Mots-clés : Capacity  allocation  Nonlinear  programming  Pricing  Service  operations  Simulation Index. décimale : 001.424 Résumé : A nonlinear programming model is formulated in this paper to determine the optimal scheme of capacity allocation and prices over a multi-period planning horizon for a service provider in the absence and presence of uncertain competitive entry. The model is solved for constant, decreasing, and increasing price sensitivities employing a combination of analytical and numerical methods. The study highlights the importance of advance selling of service prior to its eventual consumption in the spot period and investigates the impact of uncertain competitive entry on the optimal capacity allocation policy and its related profit if the entry is more or less likely or if the rival is more or less influential. The findings of the study reveal that the conclusions drawn from a two-period model are not necessarily generalizable to a model of a multi-period planning horizon. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n5/abs/jors200929a.html [article] Optimal multi-period service capacity allocation and pricing allowing for uncertain competitive entry [texte imprimé] / H. Zhang, Auteur ; H. I. Mesak, Auteur . - 2010 . - pp. 780–789. Recherche opérationnelle Langues : Anglais (eng) in Journal of the operational research society (JORS) > Vol. 61 N° 5 (Mai 2010) . - pp. 780–789 Mots-clés : Capacity  allocation  Nonlinear  programming  Pricing  Service  operations  Simulation Index. décimale : 001.424 Résumé : A nonlinear programming model is formulated in this paper to determine the optimal scheme of capacity allocation and prices over a multi-period planning horizon for a service provider in the absence and presence of uncertain competitive entry. The model is solved for constant, decreasing, and increasing price sensitivities employing a combination of analytical and numerical methods. The study highlights the importance of advance selling of service prior to its eventual consumption in the spot period and investigates the impact of uncertain competitive entry on the optimal capacity allocation policy and its related profit if the entry is more or less likely or if the rival is more or less influential. The findings of the study reveal that the conclusions drawn from a two-period model are not necessarily generalizable to a model of a multi-period planning horizon. DEWEY : 001.424 ISSN : 0361-5682 En ligne : http://www.palgrave-journals.com/jors/journal/v61/n5/abs/jors200929a.html

Study on the corrosion behavior of NdFeB permanent magnets in nitric acid and oxalic acid solutions with electrochemical techniques / H. Zhang in Materials and corrosion, Vol. 62 N° 4 (Avril 2011) 

Public ISBD [article]  in Materials and corrosion > Vol. 62 N° 4 (Avril 2011) . - pp. 346–351 Titre : Study on the corrosion behavior of NdFeB permanent magnets in nitric acid and oxalic acid solutions with electrochemical techniques Type de document : texte imprimé Auteurs : H. Zhang, Auteur ; Z. L. Song, Auteur ; S. D. Mao, Auteur Année de publication : 2011 Article en page(s) : pp. 346–351 Note générale : Génie Mécanique Langues : Anglais (eng) Mots-clés : Corrosion  behavior  Corrosion  mechanisms  Electrochemical  measurements  Electrochemical  noise  NdFeB  magnets Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Corrosion behavior of sintered NdFeB magnets in nitric acid and oxalic acid was investigated. The experiment results indicated that NdFeB is strongly corroded in nitric acid solution, and is passivated in oxalic acid solution. Based on the corrosion behavior, the possible corrosion mechanisms are discussed. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905498/abstract [article] Study on the corrosion behavior of NdFeB permanent magnets in nitric acid and oxalic acid solutions with electrochemical techniques [texte imprimé] / H. Zhang, Auteur ; Z. L. Song, Auteur ; S. D. Mao, Auteur . - 2011 . - pp. 346–351. Génie Mécanique Langues : Anglais (eng) in Materials and corrosion > Vol. 62 N° 4 (Avril 2011) . - pp. 346–351 Mots-clés : Corrosion  behavior  Corrosion  mechanisms  Electrochemical  measurements  Electrochemical  noise  NdFeB  magnets Index. décimale : 620.1 Essais des matériaux. Défauts des matériaux. Protection des matériaux Résumé : Corrosion behavior of sintered NdFeB magnets in nitric acid and oxalic acid was investigated. The experiment results indicated that NdFeB is strongly corroded in nitric acid solution, and is passivated in oxalic acid solution. Based on the corrosion behavior, the possible corrosion mechanisms are discussed. DEWEY : 620.1 ISSN : 0947-5117 En ligne : http://onlinelibrary.wiley.com/doi/10.1002/maco.200905498/abstract