The electron stimulated desorption was used to measure the surface diffusivity of atomic deuterium on clean and boron modified Ni 3(Al, Ti)(110) surfaces. Boron dosing was performed using a solid state boron ion sourc...The electron stimulated desorption was used to measure the surface diffusivity of atomic deuterium on clean and boron modified Ni 3(Al, Ti)(110) surfaces. Boron dosing was performed using a solid state boron ion source. Earlier studies showed that boron dissociates water readily at temperatures as low as 130?K and that the resulting atomic hydrogen is bound to the surface strongly. The surface diffusion coefficient of atomic D on 0.05 monolayer boron modified surface was measured to be about 10 times smaller than that on the clean surface. This slower diffusion of atomic hydrogen may explain why boron improves the ductility of polycrystalline Ni 3Al in moist environments.展开更多
This research plans to evaluate the changes and evolutions from the real world of key account management compared to literature review： How decisions are taken, what processes help to be successful on tenders, how to...This research plans to evaluate the changes and evolutions from the real world of key account management compared to literature review： How decisions are taken, what processes help to be successful on tenders, how to cooperate on a world basis, what methods facilitate conclusions. This work looks for a measure of evolution and changes during a negotiation process by KAM compared to existing literature research. Key account negotiators take strategic dimensions into account when starting a negotiation process. They measure the cost of negotiations, help their clients to position themselves properly, and develop partnerships. In general, researchers are more interested in organization and clients than in integrated processes. The process analysis is built on an in-depth analysis of Key Account Management （KAM） on three matters： an in-depth interview of 20 Key Account Managers from such companies as Air Liquide, Matra, Alcatel, GEC Alstom, Bull, EADS, PPG, an advertising agency and Omnicom on prospecting, partnerships, client’s effectiveness optimization, client’s qualification, lobbies, networks, international accounts. This research shows how KAM faces complex situations, how training and monitoring bring solutions to difficult situations, how information is managed through transparency relationships, TV shows, press media, information from shows and fairs, competitors evaluation. This work conceptualizes the KAM negotiation process and permits to managers to identify the different negotiation steps from their numerous mutual professional witnesses. The number of companies could have been larger, but we interviewed each salesperson in depth. Future work on key account salespeople should consider the following subjects： influence of KAM on tenders. Which ethical steps KAM can take with client companies to improve results. Innovation perception by clients is as a tool for success.展开更多
Background: Alopecia areata is a common condition of patchy hair loss that has been postulated to have an autoimmune pathogenesis involving inflammatory cytokines, including tumor necrosis factor (TNF) α. Etanercept ...Background: Alopecia areata is a common condition of patchy hair loss that has been postulated to have an autoimmune pathogenesis involving inflammatory cytokines, including tumor necrosis factor (TNF) α. Etanercept is a novel medication that blocks TNF-α-mediated processes. We report a case involving the recurrence of alopecia areata in a patient receiving etanercept. Observations: We describe a 49-year-old man with a history of rheumatoid arthritis and alopecia areata who developed a recurrence of his alopecia areata while being treated with etanercept for more than 2 years. Conclusions: The anti-TNF-αeffect of etanercept therapy may not be sufficient to prevent the recurrence of alopecia areata. The possible role of TNF-αin the pathogenesis of alopecia areata may be called into question if our observation is repeated.展开更多
The authors investigate the global properties of general autonomous systems on the plane and establish criteria for the nonexistence, existence and uniqueness of limit cycles. As application examples, the limit cycles...The authors investigate the global properties of general autonomous systems on the plane and establish criteria for the nonexistence, existence and uniqueness of limit cycles. As application examples, the limit cycles for some polynomial systems are studied.展开更多
The panel-type structures used in aerospace engineering can be subjected to severe highfrequency acoustic loadings in service. This paper evaluates the frequency-dependent random fatigue of panel-type structures made ...The panel-type structures used in aerospace engineering can be subjected to severe highfrequency acoustic loadings in service. This paper evaluates the frequency-dependent random fatigue of panel-type structures made of ceramic matrix composites（CMCs） under acoustic loadings. Firstly, the high-frequency random responses from the broadband random excitation will result in more stress cycles in a deinite period of time. The probability density distributions of stress amplitudes will be different in different frequency bandwidths, though the peak stress estimations are identical. Secondly, the fatigue properties of CMCs can be highly frequency-dependent. The fatigue evaluation method for the random vibration case is adopted to evaluate the fatigue damage of a representative stiffened panel structure. The frequency effect through S-N curves on random fatigue damage is numerically veriied. Finally, a parameter is demonstrated to characterize the mean vibration frequency of a random process, and hence this parameter can further be considered as a reasonable loading frequency in the fatigue tests of CMCs to obtain more reliable S-N curves.Therefore, the inluence of vibration frequency can be incorporated in the random fatigue model from the two perspectives.展开更多
The authors establish the existence of a large class of mathematical entropies (the so-called weak entropies) associated with the Euler equations for an isentropic, compressible fluid governed by a general pressure la...The authors establish the existence of a large class of mathematical entropies (the so-called weak entropies) associated with the Euler equations for an isentropic, compressible fluid governed by a general pressure law. A mild assumption on the behavior of the pressure law near the vacuum is solely required. The analysis is based on an asymptotic expansion of the fundamental solution (called here the entropy kernel) of a highly singular Euler- Poisson-Darboux equation. The entropy kernel is only Holder continuous and its regularity is carefully inversti- gated. Relying on a notion introduced earlier by the authors, it is also proven that, for the Euler equations, the set of eatropy flux-splittings coincides with the set of entropies-entropy fluxes. There results imply the existence of a flux-splitting consistent with all of the entropy inequalities.展开更多
An approach is introduced to construct global discontinuous solutions in L~∞ for HamiltonJacobi equations. This approach allows the initial data only in L~∞ and applies to the equations with nonconvex Hamiltonians....An approach is introduced to construct global discontinuous solutions in L~∞ for HamiltonJacobi equations. This approach allows the initial data only in L~∞ and applies to the equations with nonconvex Hamiltonians. The profit functions are introduced to formulate the notion of discoatinuous solutions in L~∞. The existence of global discontinuous solutions in L~∞ is established. These solutions in L~∞ coincide with the viscosity solutions and the minimax solutions, provided that the initial data are continuous. A prototypical equation is analyzed to examine the L~∞ stability of our L~∞ solutions. The analysis also shows that global discontinuous solutions are determined by the topology in which the initial data are approximated.展开更多
We establish a criterion for the uniqueness of periodic solutions for a class of second-order equations. We also give an application to a polynomial system and corrections to some known results.
文摘The electron stimulated desorption was used to measure the surface diffusivity of atomic deuterium on clean and boron modified Ni 3(Al, Ti)(110) surfaces. Boron dosing was performed using a solid state boron ion source. Earlier studies showed that boron dissociates water readily at temperatures as low as 130?K and that the resulting atomic hydrogen is bound to the surface strongly. The surface diffusion coefficient of atomic D on 0.05 monolayer boron modified surface was measured to be about 10 times smaller than that on the clean surface. This slower diffusion of atomic hydrogen may explain why boron improves the ductility of polycrystalline Ni 3Al in moist environments.
文摘This research plans to evaluate the changes and evolutions from the real world of key account management compared to literature review： How decisions are taken, what processes help to be successful on tenders, how to cooperate on a world basis, what methods facilitate conclusions. This work looks for a measure of evolution and changes during a negotiation process by KAM compared to existing literature research. Key account negotiators take strategic dimensions into account when starting a negotiation process. They measure the cost of negotiations, help their clients to position themselves properly, and develop partnerships. In general, researchers are more interested in organization and clients than in integrated processes. The process analysis is built on an in-depth analysis of Key Account Management （KAM） on three matters： an in-depth interview of 20 Key Account Managers from such companies as Air Liquide, Matra, Alcatel, GEC Alstom, Bull, EADS, PPG, an advertising agency and Omnicom on prospecting, partnerships, client’s effectiveness optimization, client’s qualification, lobbies, networks, international accounts. This research shows how KAM faces complex situations, how training and monitoring bring solutions to difficult situations, how information is managed through transparency relationships, TV shows, press media, information from shows and fairs, competitors evaluation. This work conceptualizes the KAM negotiation process and permits to managers to identify the different negotiation steps from their numerous mutual professional witnesses. The number of companies could have been larger, but we interviewed each salesperson in depth. Future work on key account salespeople should consider the following subjects： influence of KAM on tenders. Which ethical steps KAM can take with client companies to improve results. Innovation perception by clients is as a tool for success.
文摘Background: Alopecia areata is a common condition of patchy hair loss that has been postulated to have an autoimmune pathogenesis involving inflammatory cytokines, including tumor necrosis factor (TNF) α. Etanercept is a novel medication that blocks TNF-α-mediated processes. We report a case involving the recurrence of alopecia areata in a patient receiving etanercept. Observations: We describe a 49-year-old man with a history of rheumatoid arthritis and alopecia areata who developed a recurrence of his alopecia areata while being treated with etanercept for more than 2 years. Conclusions: The anti-TNF-αeffect of etanercept therapy may not be sufficient to prevent the recurrence of alopecia areata. The possible role of TNF-αin the pathogenesis of alopecia areata may be called into question if our observation is repeated.
基金the National Natural Science Foundation of China (No. 19531070) andShuGuang Plan.
文摘The authors investigate the global properties of general autonomous systems on the plane and establish criteria for the nonexistence, existence and uniqueness of limit cycles. As application examples, the limit cycles for some polynomial systems are studied.
基金supports from the National Natural Science Foundation of China (No. 11572086 , No. 11402052 )the New Century Excellent Talent in University (NCET-11-0086)+3 种基金the Natural Science Foundation of Jiangsu province (No. BK20140616 )the Fundamental Research Funds for the Central Universities and the Scientiic Research Innovation Program of Jiangsu Province College Postgraduates (KYLX_0093, KYLX15_0092)the China Scholarship Council ( 201506090047 )the Ministry of Education, Science and Technological Development of Republic of Serbia ( TR 35011 and ON 74001 )
文摘The panel-type structures used in aerospace engineering can be subjected to severe highfrequency acoustic loadings in service. This paper evaluates the frequency-dependent random fatigue of panel-type structures made of ceramic matrix composites（CMCs） under acoustic loadings. Firstly, the high-frequency random responses from the broadband random excitation will result in more stress cycles in a deinite period of time. The probability density distributions of stress amplitudes will be different in different frequency bandwidths, though the peak stress estimations are identical. Secondly, the fatigue properties of CMCs can be highly frequency-dependent. The fatigue evaluation method for the random vibration case is adopted to evaluate the fatigue damage of a representative stiffened panel structure. The frequency effect through S-N curves on random fatigue damage is numerically veriied. Finally, a parameter is demonstrated to characterize the mean vibration frequency of a random process, and hence this parameter can further be considered as a reasonable loading frequency in the fatigue tests of CMCs to obtain more reliable S-N curves.Therefore, the inluence of vibration frequency can be incorporated in the random fatigue model from the two perspectives.
文摘The authors establish the existence of a large class of mathematical entropies (the so-called weak entropies) associated with the Euler equations for an isentropic, compressible fluid governed by a general pressure law. A mild assumption on the behavior of the pressure law near the vacuum is solely required. The analysis is based on an asymptotic expansion of the fundamental solution (called here the entropy kernel) of a highly singular Euler- Poisson-Darboux equation. The entropy kernel is only Holder continuous and its regularity is carefully inversti- gated. Relying on a notion introduced earlier by the authors, it is also proven that, for the Euler equations, the set of eatropy flux-splittings coincides with the set of entropies-entropy fluxes. There results imply the existence of a flux-splitting consistent with all of the entropy inequalities.
文摘An approach is introduced to construct global discontinuous solutions in L~∞ for HamiltonJacobi equations. This approach allows the initial data only in L~∞ and applies to the equations with nonconvex Hamiltonians. The profit functions are introduced to formulate the notion of discoatinuous solutions in L~∞. The existence of global discontinuous solutions in L~∞ is established. These solutions in L~∞ coincide with the viscosity solutions and the minimax solutions, provided that the initial data are continuous. A prototypical equation is analyzed to examine the L~∞ stability of our L~∞ solutions. The analysis also shows that global discontinuous solutions are determined by the topology in which the initial data are approximated.
基金Project supported by the National Natural Science Foundation of China(10371072)
文摘We establish a criterion for the uniqueness of periodic solutions for a class of second-order equations. We also give an application to a polynomial system and corrections to some known results.
