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131.
Jean-Claude Loulergue Sen-Lu Xu 《Journal of Infrared, Millimeter and Terahertz Waves》1986,7(1):171-182
A thermal imaging system using a liquid-liquid interface has been studied, which utilizes the extreme temperature sensitivity of surface tension (Marangoni Effect). Theoretical considerations for the design and the operating conditions of the device are given. The experimental results using a detection by polarization interferometer indicate that the limitations on such a device are primarily due to the finite film thickness of the upper solution (on the order of 50–80 μm). This system was able to image 1°C with a limiting resolution of ten lines pair per millimeter. 相似文献
132.
Sara Bals Jo Verbeeck Gustaaf Van Tendeloo Yi-Lin Liu Jean-Claude Grivel 《Journal of the American Ceramic Society》2005,88(2):431-436
The microstructural and compositional evolution during initial annealing of a superconducting (Bi,Pb)2 Sr2 Ca2 Cu3 O10+δ /Ag tape is studied using quantitative transmission electron microscopy. Special attention is devoted to the occurrence of Pb-rich liquids, which are crucial for the Bi2 Sr2 CaCu2 O8+δ to (Bi,Pb)2 Sr2 Ca2 Cu3 O10+δ transformation. Ca and/or Pb-rich (Bi,Pb)2 Sr2 CaCu2 O8+δ grains dissolve into a liquid, which reacts with Ca-rich phases to increase the liquid's Ca-content. This leads to (Bi,Pb)2 Sr2 Ca2 Cu3 O10+δ formation. Apparently, a Ca/Sr ratio of around 1 is sufficient to keep (Bi,Pb)2 Sr2 Ca2 Cu3 O10+δ nucleation going. It is confirmed that Ag particles are transported from the Ag-sheath into the oxide core by the liquid and not by mechanical treatment of the tape. 相似文献
133.
Magalie Roy Michel Gubelmann-Bonneau Hervé Ponceblanc Jean-Claude Volta 《Catalysis Letters》1996,42(1-2):93-97
Dispersion of vanadium and molybdenum phosphates on titanium oxide (anatase) below the monolayer gives good catalysts for direct oxidation of ethane to acetic acid. By comparison with the dispersion of only vanadium phosphate, the higher selectivity to acetic acid for vanadium and molybdenum phosphates has been explained by an interaction between molybdenum and vanadium as it can be deduced from electron spin resonance and laser Raman spectroscopy studies. 相似文献
134.
Yannis Chryssoulakis Jean-Claude Poignet Georgia Manoli 《Journal of Applied Electrochemistry》1987,17(4):857-867
Electrochemical reduction of AlCl3 dissolved in acidic AlCl3-n-butyl-pyridinium chloride melt was studied by linear sweep voltammetry and chronopotentiometry at tungsten and platinum electrodes, in the Al2Cl 7 ? concentration range 0.3 to 0.5 M between 30 and 60°C. Al2Cl 7 ? bulk reduction was preceded by a nucleation (tungsten) or alloy formation phenomenon (platinum). The overall results agree rather well with the mechanism: $$\begin{gathered} 2AlCl_4^ - \rightleftarrows Al_2 Cl_7^ - + Cl^ - \hfill \\ 4Al_2 Cl_7^ - + 3e \rightleftarrows Al + 7AlCl_4^ - \hfill \\ \end{gathered} $$ The electrochemical reaction appeared quasi-reversible. Calculated values of the product of the transfer coefficient by the number of the electron exchanged in the rate determining step were in the range 0.45 to 0.7. Diffusion coefficients for Al2Cl 7 ? were calculated. 相似文献
135.
The air circulation inside an enclosure with multiple openings and local heat sources was studied by means of a mathematical model. After a number of comparisons to studies in an experimental apparatus, it was concluded that a turbulence model should be introduced in order to improve the mathematical simulation. Two turbulence models, one based on the algebraic and the other on the differential (K-?-G) model of the turbulent viscosity, were investigated. The differential model provided only small improvements in the results and increased the running costs substantially when compared to the algebraic model. Hence the utilisation of the differential model was not justified in these simulations. The combined effect of the forced convection through the enclosure and the natural convection from the heat sources was simulated in an attempt to study the air circulation and the air temperature inside the building of an aluminum reduction plant. 相似文献
136.
Chenal Alexandre; Nizard Philippe; Forge Vincent; Pugniere Martine; Roy Marie-Odile; Mani Jean-Claude; Guillain Florent; Gillet Daniel 《Protein engineering, design & selection : PEDS》2002,15(5):383-391
We investigated whether the structural and functional behaviorsof two unrelated protein domains were modified when fused. TheIgG-binding protein ZZ derived from staphylococcal protein Awas fused to the N- and/or C-terminus of the diphtheria toxintransmembrane domain (T). T undergoes a conformational changefrom a soluble native state at neutral pH to a molten globule-likestate at acidic pH, leading to its interaction with membranes.We found that this molten globule state was not connected tothe GdnHCl-induced unfolding pathway of T. The pH-induced transitionof T, and also the unfolding of T and ZZ at neutral and acidicpH, were unchanged whether the domains were isolated or fused.The position of ZZ, however, influenced the solubility of Tnear its pKi. SPR measurements revealed that T has a high affinityfor membranes, isolated or within the fusion proteins (KD<10-11 M). This work shows that in the case of T and ZZ, thefusion of protein domains with different stabilities does notalter the structural changes involved in folding and function.This supports the use of T as a soluble membrane anchor. 相似文献
137.
Particle systems are important building block for simulating vivid and detail-rich effects in virtual world.One of the most difficult aspects of particle systems has been detecting collisions between particles and mesh surface.Due to the huge computation,a variety of proxy-based approaches have been proposed recently to perform visually correct simulation.However,all either limit the complexity of the scene,fail to guarantee non-penetration,or are too slow for real-time use with many particles.In this paper,we propose a new octree-based proxy for colliding particles with meshes on the GPU.Our approach works by subdividing the scene mesh with an octree in which each leaf node associates with a representative normal corresponding to the normals of the triangles that intersect the node.We present a view-visible method,which is suitable for both closed and non-closed models,to label the empty leaf nodes adjacent to nonempty ones with appropriate back/front property,allowing particles to collide with both sides of the scene mesh.We show how collisions can be performed robustly on this proxy structure in place of the original mesh,and describe an extension that allows for fast traversal of the octree structure on the GPU.The experiments show that the proposed method is fast enough for real-time performance with millions of particles interacting with complex scenes. 相似文献
138.
Yliès Falcone Laurent Mounier Jean-Claude Fernandez Jean-Luc Richier 《Formal Methods in System Design》2011,38(3):223-262
Runtime enforcement is a powerful technique to ensure that a program will respect a given set of properties. We extend previous
work on this topic in several directions. Firstly, we propose a generic notion of enforcement monitors based on a memory device
and finite sets of control states and enforcement operations. Moreover, we specify their enforcement abilities w.r.t. the
general Safety-Progress classification of properties. Furthermore, we propose a systematic technique to produce a monitor from the automaton recognizing a given safety, guarantee, obligation or response property.
Finally, we show that this notion of enforcement monitors is more amenable to implementation and encompasses previous runtime
enforcement mechanisms. 相似文献
139.
Spatial interaction (SI) is the process whereby entities at different points in physical space make contacts, demand/supply decisions or locational choices. The entities can be individuals or firms and the choices can include housing, jobs, production quantities, exports, imports, face-to-face contacts, schools, retail centres and activity centres. The first SI models can be grouped under the generic heading gravity models. Their main characteristic is that they model the behaviour of demand or supply segments, rather than that of individuals and firms. This article traces the development of these models from their inception in the early part of the twentieth century to the present. The key advances include the replacement of the gravity analogy by the more general concepts of entropy or information theory, a statistical framework commonly used in physics. With the arrival of the regional science paradigm over 50 years ago, a key challenge has been to broaden these models compared to those arising in spatial economics, thus arriving at a more inclusive probabilistic framework. These efforts are discussed here, as well as inclusion of geographical advances, embracing activities as generators of travel, time-geography, recognition of spatial interdependencies, and use of neuro-computing principles.JEL Classification:
C190, C450, C610, R00 相似文献
140.
本课题采用理论分析方法研究了现有低浓磨浆强度对于不含挡坝等距直齿磨盘低浓磨浆过程的强度表征效果。结果表明,单个磨齿交错区域的净法向力(fnnet)及切向力(ftnet)是目前唯一具有实际意义的有效低浓磨浆强度,其不仅适用于不含挡坝等距直齿磨盘低浓磨浆过程的表征,并可扩展至含挡坝磨盘及弧形齿磨盘。而具有实际意义的比边缘负荷(SELC及SELT)的应用具有一定的局限性,仅适用于恒定参数磨盘低浓磨浆过程的强度表征。实际上,低浓磨浆强度的合理建立、选择及应用不仅反映对磨浆机理的认知,且直接影响低浓磨浆过程的优化控制、齿型参数设计及选择。 相似文献