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71.
The effective mechanical properties of a polyurethane adhesive (oligoetherdiol, ‐triol, MDI) in gold joints (bond line thickness, dP = 35–550 µm) are studied in the linear deformation range by dynamic mechanical analysis in shear mode. These properties depend on dP: thin ones possess a higher dynamic glass transition temperature and show a narrower glass transition than the thick ones. The storage modulus rises with decreasing dP for the rubbery plateau. The results attest mechanical interphases in the polyurethane with increased crosslink density and reduced cooperative mobility than in bulk. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42058. 相似文献
72.
In this paper, we analyze the differences, similarities and complementariness which exist between two major domains of nowadays
information security: intrusion detection on one hand, virology and anti-viruses technologies on the other hand. This analysis
is built from two points of view. First, we compare, through the definitions that have been proposed by researchers of the
two communities, the goals that are actually pursued in each domain. Then, we compare the techniques that have been developed
to reach these goals. In the conclusion, we summarize our analysis and suggest that alert correlation is one way to make the
two fields cooperate. 相似文献
73.
Florent Monestier Jean-Jacques Simon Philippe Torchio Ludovic Escoubas Franois Flory Sandrine Bailly Remi de Bettignies Stephane Guillerez Christophe Defranoux 《Solar Energy Materials & Solar Cells》2007,91(5):405-410
We have investigated the short-circuit current density of organic solar cells based on poly (3-hexylthiophene)(P3HT)/6,6-phenyl C61-butyric acid methyl ester (PCBM) blend. In order to model charge collection efficiencies with respect to short circuit density in such blends, a full optical modeling of the cell is performed. From the distribution of the electromagnetic field, we compute the rate of exciton generation. This exciton generation rate is used as input in the transport equations of holes and electrons. Charge densities at steady state are obtained as solutions are used for computing short-circuit current densities generated in the cell. The dependence of short-circuit current densities versus the thickness of the blend is analyzed and compared with our experimental data and with data extracted from the literature. 相似文献
74.
Sofía De-León Almaraz Catherine Azzaro-Pantel Ludovic Montastruc Luc Pibouleau Oscar Baez Senties 《International Journal of Hydrogen Energy》2013
This work considers the potential future use of hydrogen in fuel cell electrical vehicles to face problems such as global warming, air pollution, energy security and competitiveness. The lack of current infrastructure has been identified as one of the main barriers to develop the hydrogen economy. This work is focused on the design of a hydrogen supply chain through mixed integer linear programming used to find the best solutions for a multi-objective optimization problem in which three objectives are involved, i.e., cost, global warming potential and safety risk. This problem is solved by implementing an ?-constraint method. The solution consists of a Pareto front, corresponding to different design strategies in the associated variable space. Multiple choice decision making is then recommended to find the best solution through an M-TOPSIS analysis. The model is applied to the Great Britain case study previously treated in the dedicated literature. Mono and multicriteria optimizations exhibit some differences concerning the degree of centralization of the network and the selection of the production technology type. 相似文献
75.
A new, simple, and fast one-pot synthesis of supported Au or Ag nanoparticles is implemented, for which a reactive Fe(II)-bearing green rust inorganic particle is used as an individual micro-reactor acting as both the reducing agent and support for the resulting metal nanoparticles. The mechanism involves both the solid-state oxidation of the green rust support (sulfate or carbonate) and the reduction-precipitation of soluble metal precursor. The resulting nanohybrids have a platy inorganic part supporting about one to ten nanoparticles with sizes in the 20 to 120 nm range. 相似文献
76.
Ludovic Charpentier Marianne Balat-Pichelin Diletta Sciti Laura Silvestroni 《Journal of the European Ceramic Society》2013,33(15-16):2867-2878
Ultra-high temperature ceramics having melting points above 3500 K and high thermal conductivities are envisaged as future receivers of concentrating solar power plants. The high pressure and solar temperature reactor (Réacteur Hautes Pression et Température Solaire, REHPTS) implemented at the focus of the Odeillo 5 kW solar furnace was used to investigate the oxidation of three refractory carbides containing different sintering additives (HfC/MoSi2, ZrC/MoSi2, ZrC/TaSi2) that could be considered as promising candidates. The concentration of the additive, TaSi2 or MoSi2, was 20 vol%. Each kind of sample was oxidized in air for 20 min at 1800, 2000 and 2200 K. Experiments were filmed using a video camera and the gaseous phases were analyzed in situ by mass spectrometry. Various post-test characterizations have shown that the nature of the carbide and additive strongly affects the composition of the oxide layer and therefore the high-temperature behaviour. 相似文献
77.
Schull G Douillard L Fiorini-Debuisschert C Charra F Mathevet F Kreher D Attias AJ 《Nano letters》2006,6(7):1360-1363
A two-dimensional molecular sieve has been realized. It consists of a host matrix of molecularly engineered building blocks self-assembled at the liquid-solid interface. The simultaneous size- and shape-dependent dynamics of different guest molecules is observed in situ, in real time with submolecular resolution using a scanning tunneling microscope both at the liquid-solid interface and under vacuum. The temperature-dependent dynamics reveals that the diffusion proceeds through thermally activated channeling between single-molecule surface cavities. 相似文献
78.
Tunable acousto-optic spectral imager for atmospheric composition measurements in the visible spectral domain 总被引:1,自引:0,他引:1
E Dekemper N Loodts B Van Opstal J Maes F Vanhellemont N Mateshvili G Franssens D Pieroux C Bingen C Robert L De Vos L Aballea D Fussen 《Applied optics》2012,51(25):6259-6267
We describe a new spectral imaging instrument using a TeO2 acousto-optical tunable filter (AOTF) operating in the visible domain (450-900?nm). It allows for fast (~1 second), monochromatic (FWHM ranges from 0.6?nm at 450?nm to 3.5?nm at 800?nm) picture acquisition with good spatial resolution. This instrument was designed as a breadboard of the visible channel of a new satellite-borne atmospheric limb spectral imager, named the Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere (ALTIUS), that is currently being developed. We tested its remote sensing capabilities by observing the dense, turbulent plume exhausted by a waste incinerator stack at two wavelengths sensitive to NO2. An average value of 6.0±0.4×1017 molecules?cm-2 has been obtained for the NO2 slant column density within the plume, close to the stack outlet. Although this result was obtained with a rather low accuracy, it demonstrates the potential of spectral imaging by using AOTFs in remote sensing. 相似文献
79.
Emilien Buet Jean-Baptiste Dubois Patrick Olier Ludovic Thilly Florence Lecouturier Pierre-Olivier Renault 《International Journal of Material Forming》2012,5(2):121-127
The structure refinement is a challenge for conductors used for the winding of resistive coils producing non-destructive pulsed magnetic fields over 80T. These nanocomposite conductors composed of a conducting multiscale Cu matrix embedding Nb reinforcing nanofilaments are usually manufactured by using a Severe Plastic Deformation (SPD) process based on hot extrusion, accumulative cold drawing and bundling (ADB) steps [Thilly et al. Philos Mag A 82:925, 2002]. Equal-channel angular extrusion (ECAE) is investigated here as an alternative route since it may provide faster refinement to obtain the ultrafine structure needed for optimized electrical and mechanical properties of the conductors. Therefore, copper-niobium specimens obtained by hot extrusion were processed by ECAE at room temperature. The specific die of the ECAE tool used here is constituted by a round channel with three angles corresponding to a total equivalent strain of about 2.5. Deformed samples were examined by optical microscopy and characterized by hardness profiles and x-ray diffraction (texture pole figures). After one ECAE-pass, the shape of the samples is modified but no trace of damage appeared at the Cu-Nb interfaces. An increase of the hardness values localized in the copper matrix is revealed whereas the hardness of the niobium remains unchanged. Prior to ECAE, the hot extrusion process induced a fibre texture for both copper and niobium. Two fibre texture components were observed for copper: <111> and <200>. A single <110> fibre texture component is evidenced for the niobium. After ECAE a significant variation of the texture is observed in relation with the strong shear induced by this process. 相似文献
80.