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991.
This paper presents work carried out within the Cesame project for the design of a multimedia highspeed distributed transport provider. The term transport provider is used to target a reference framework but does not preclude any standardized reference model. It gives the objectives and relates the main contributions obtained during the first year of the project. The goal of this task is to monitor, select and design services, protocols and mechanisms for defining a transport provider to support distributed multimedia services. As far as architectural aspects are concerned, a refinement of reference models is mandatory, and work on this topic has already been started within several institutions. Moreover, it is worth to mention that the transport provider will have first to run on top ofAtm/Aal networks and is expected on top of other networks. 相似文献
992.
Xinliang Xie Shuo Yin Rija-nirina Raoelison Chaoyue Chen Christophe Verdy Wenya Li Gang Ji Zhongming Ren Hanlin Liao 《材料科学技术学报》2021,86(27):20-55
Cold spraying(CS),or cold gas dynamic spray(CGDS),is an emerging solid-state powder deposition process,allowing fast and mass production and restoration of metallic components.CS of metal matrix composites(MMCs)has attracted increasing attention from academia and industry over the last decades,especially in the area of Al matrix composites(AMCs),which have demonstrated a high potential for applications in aerospace,automotive,and electronics industries.This article aims to summarize the recent development of CS-processed AMCs in terms of composite powder preparation,deposition pro-cessing,microstructure evolution,mechanical and corrosion properties.Furthermore,this review also reports the relevant research progress with the focus on post-treatments of the AMCs for CS additive manufacturing applications including heat treatment,hot rolling,and friction stir processing.Finally,the challenges and perspectives on the fabrication of advanced AMCs by CS are addressed. 相似文献
993.
Rashad Bantan Amal S. Hassan Ehab Almetwally M. Elgarhy Farrukh Jamal Christophe Chesneau Mahmoud Elsehetry 《计算机、材料和连续体(英文)》2021,68(3):2859-2875
Accelerated life testing has been widely used in product life testing experiments because it can quickly provide information on the lifetime distributions by testing products or materials at higher than basic conditional levels of stress, such as pressure, temperature, vibration, voltage, or load to induce early failures. In this paper, a step stress partially accelerated life test (SS-PALT) is regarded under the progressive type-II censored data with random removals. The removals from the test are considered to have the binomial distribution. The life times of the testing items are assumed to follow length-biased weighted Lomax distribution. The maximum likelihood method is used for estimating the model parameters of length-biased weighted Lomax. The asymptotic confidence interval estimates of the model parameters are evaluated using the Fisher information matrix. The Bayesian estimators cannot be obtained in the explicit form, so the Markov chain Monte Carlo method is employed to address this problem, which ensures both obtaining the Bayesian estimates as well as constructing the credible interval of the involved parameters. The precision of the Bayesian estimates and the maximum likelihood estimates are compared by simulations. In addition, to compare the performance of the considered confidence intervals for different parameter values and sample sizes. The Bootstrap confidence intervals give more accurate results than the approximate confidence intervals since the lengths of the former are less than the lengths of latter, for different sample sizes, observed failures, and censoring schemes, in most cases. Also, the percentile Bootstrap confidence intervals give more accurate results than Bootstrap-t since the lengths of the former are less than the lengths of latter for different sample sizes, observed failures, and censoring schemes, in most cases. Further performance comparison is conducted by the experiments with real data. 相似文献
994.
The main goal of this paper is to provide a general methodology and a practical approach for the design of gait pattern for biped robotic applications directly usable by researchers and engineers. This approach, which is based on CMAC neural network, is an alternative way in comparison to the traditional Central Pattern Generator. In the proposed method, the CMAC neural networks are used to learn basic motions (e.g. reference gait) and a Fuzzy Inference System allows to merge these reference motions in order to built more complex gaits. The results of our biped robotic applications show how to design a self-adaptive gait pattern according to average velocity and external perturbations. 相似文献
995.
The research presented in this paper introduces a relative representation of trajectories in space and time. The objective
is to represent space the way it is perceived by a moving observer acting in the environment, and to provide a complementary
view to the usual absolute vision of space. Trajectories are characterized from the perception of a moving observer where
relative positions and relative velocities are the basic primitives. This allows for a formal identification of elementary
trajectory configurations, and their relationships with the regions that compose the environment. The properties of the model
are studied, including transitions and composition tables. These properties characterize trajectory transitions by the underlying
processes that semantically qualify them. The approach provides a representation that might help the understanding of trajectory
patterns in space and time.
相似文献
Valérie NoyonEmail: |
996.
997.
The reaction between the diglycidylether of bisphenol A (DGEBA) and 4,9-dioxa-1,12-dodecanediamine (DDDD) has been studied by means of isothermal and dynamic differential scanning calorimetry. The enthalpy of the reaction of an epoxy group with an amino-hydrogen has been determined to be 112 ± 5 kJ/mol. A kinetic model has been validated. It involves two competitive mechanisms: one is catalysed by the hydroxy groups initially present on the epoxy chain or generated during the reaction (activation energy 77 ± 5 kJ/mol), the other is not catalysed with a higher activation energy (103 ± 3 kJ/mol). For each isothermal curing, the kinetics are not modified by gelation. Evaluated from the gel times, the overall activation energy of the reaction is equal to 62 ± 2 kJ/mol. 相似文献
998.
Lipid composition of normal and hypertrophic bovine thyroids 总被引:1,自引:0,他引:1
The phospholipid content of bovine thyroid tissue amounts to 70% of total lipid. Triglycerides and cholesterol are the main neutral lipids. Only trace amounts of free fatty acid and esterified cholesterol are found, while two not yet identified components also are present. The distribution of lipid phosphorus in the different phospholipid classes is as follows: phosphatidyl choline, 43.0%; phosphatidyl ethanolamine, 25.2%; phosphatidyl serine, 5.6%; phosphatidyl inositol, 6.5%; sphingomyelin, 14.0%; cardiolipin, 2.8%; lysophosphatidyl choline, <1%; and phosphatidic acid, <1%. The phosphatidyl ethanolamines are rich in plasmalogens. The fatty acid patterns in the different lipid classes are reported. The essential differences between normal and hypertrophic bovine thyroid tissue are higher water content and lower triglyceride and sphingomyelin values for hypertrophic tissue. 相似文献
999.
Haifaa Mokbel Cyril Poriel Joëlle Rault‐Berthelot Frédéric Dumur Didier Gigmes Joumana Toufaily Tayssir Hamieh Daniela Cordella Christophe Detrembleur Jacques Lalevée 《应用聚合物科学杂志》2016,133(12)
A novel photoinitiator based on a spiroxanthene scaffold in the presence of an iodonium salt is proposed for the cationic ring‐opening polymerization of a diepoxide, as well as for the free‐radical polymerization of an acrylate upon violet LED exposure (385 and 405 nm). Good‐to‐excellent rates of polymerization and final conversions are obtained. These systems are characterized by a higher reactivity compared with that of anthracene/iodonium salt used as reference for cationic near UV polymerization. The addition of a poly(ionic liquid) improves the cationic polymerization profiles. The photochemical mechanisms are studied by steady‐state photolysis, fluorescence, and electron spin resonance spin‐trapping techniques. Molecular orbital calculations give an insight into the light absorption properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43213. 相似文献
1000.
The use of liquid sodium as a coolant in sodium-cooled fast reactors (SFR) circuits requires studying the consequences of a sodium fire for safety analysis, and particularly the toxicological impact of sodium fire aerosols. More particularly, the carbonation of sodium fire aerosols from sodium hydroxide (NaOH) to sodium carbonate (Na2CO3) is investigated. A new kinetic model, based on the CO2 reactive absorption and the two-film theory, is developed to describe the carbonation process of NaOH solutions, taking into account the NaOH aerosols' initial characteristics in equilibrium with the atmosphere. This model is applied for the case of NaOH aerosols considering the CO2 absorption at the particle external surface. The estimation for the model parameters is detailed as function of NaOH degree of conversion, relative humidity (RH), and temperature. By comparisons with available experimental data, the absorption interfacial area is empirically estimated over the studied range of RH and initial particle diameter. The global sensitivity study of the model confirms its capabilities to describe NaOH aerosols' carbonation, waiting for new experimental data for validation.
© 2016 American Association for Aerosol Research 相似文献