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121.
Armand Buchs Alain Glangetas Jean M. J. Tronchet 《Journal of mass spectrometry : JMS》1975,10(11):970-980
The mass spectra of three stereoisomeric 1,2-5,6-di-O-isopropylidene-α-D -hexofuranoses have been investigated. Fragmentation mechanisms based upon the results which were obtained with deuterium labelled molecules are proposed. 相似文献
122.
Armand Gautier 《Fresenius' Journal of Analytical Chemistry》1901,40(6):420-422
Ohne Zusammenfassung 相似文献
123.
Armand Bertrand 《Fresenius' Journal of Analytical Chemistry》1880,19(1):346
Ohne Zusammenfassung 相似文献
124.
S. Charpentier A. Kassiba S. Fusil X. Armand M. Cauchetier J. C. Fayet J. Emery 《Applied magnetic resonance》1997,12(2-3):255-267
EPR investigations are performed in SiC and SiOC nanometric powders annealed between 1200 and 1800°C. By using different EPR frequency bands and a suitable spectra analysis, three quite different paramagnetic defects with well defined $\tilde g_i $ (i=1, 2, 3) and hyperfine $\tilde A_i $ (i=1, 2) tensors account for the EPR signal in these materials. The defects are characterized by $\tilde g_1 $ (g 1 ‖ =2.0046(3), g 1 ? =2.0023(3)), $\tilde g_2 $ (g 2 ‖ =2.0037(3), g 2 ? =2.0028(3)) and isotropic $\tilde g_3 $ (2.0030(3)) tensors. In SiC powders, the defects assignment is discussed with respect to the different SiC forms, namely α-SiC and β-SiC polytypes as well as amorphous SiC and carbon present in minor concentration in the network. In SiOC powders, the above defects are evidenced only at high annealing temperature (T a≥1200°C) when the oxygen contained is highly reduced. 相似文献
125.
Yahya Pezeshki Armand Baboli Naoufel Cheikhrouhou Mohammad Modarres Mohammad R. Akbari Jokar 《European Journal of Operational Research》2013
Coordination of decentralized supply chains using contract design is a problem that has been widely addressed in the literature. We consider a divergent supply chain including a supplier and several retailers producing fashion products with short sale seasons. The retailers cooperate with the supplier as sales agents; i.e., they work in the framework of revenue sharing contracts. Because of their proximity to the market, retailers can provide more accurate demand forecasts to the supplier that is used to decide on issues such as capacity building and market prices with regard to retailers stiff due dates, different lead times and different price-dependent demand functions. To ensure abundant supply and cope with the demand variability, the retailers have an incentive to exaggerate their private forecast information. In this study, we propose a new rewarding-punishing coordination mechanism based on trust between supply chain tiers, considered as a differentiation factor between honest and deceptive partners. An optimization model is developed as a building block of this mechanism. An approximation method is used to simplify and solve the problem. The model is then implemented using Monte-Carlo simulation in four different situations, according to 10 different strategies for forecast information sharing. The findings from the tests show that the mechanism including trust as a decisional factor performs better than ‘No Trust’ mechanism in all situations. These results suggest that taking into account Trust in designing coordination mechanism may have significant influence on the financial performance of the supply chain. 相似文献
126.
Kazi Akikur Rahman Tadeusz Bak Armand Atanacio Mihail Ionescu Janusz Nowotny 《Ionics》2018,24(2):327-341
The present chain of five papers considers the concept of solar-to-chemical energy conversion using TiO2-based semiconductors. The series reports the effect of chromium on the key performance-related properties of polycrystalline TiO2 (rutile), including electronic structure, photocatalytic activity, intrinsic defect disorder, electrochemical coupling and surface versus bulk properties. In this work, we show that the effect of chromium on photocatalytic performance of TiO2 depends on its elemental content and the related defect disorder that is determined by oxygen activity in the oxide lattice. At high oxygen activity, chromium leads to enhanced photocatalytic performance only for dilute solid solutions (up to 0.04–0.043 at.% Cr). Higher chromium content results in a decrease of photocatalytic activity below that for pure TiO2, despite the observed substantial decrease of the band gap. The photocatalytic performance of Cr-doped TiO2 annealed in reducing conditions is low within the entire studied range of compositions. The obtained results led to derivation of a theoretical model representing the mechanism of the light-induced reactivity of TiO2 with water and the related charge transfer. The photocatalytic performance is considered in terms of a competitive effect of several key performance-related properties. The performance is predominantly influenced by the concentration of titanium vacancies acting as reactive surface sites related to anodic charge transfer. 相似文献
127.
Supported by the National Science Foundation during 1986–1988 at the Mathematical Sciences Research Institute, Berkeley, and
at the Institute for Advanced Study, Princeton. 相似文献
128.
129.
Acetylenic and diacetylenic mesomorphic monomers have been prepared in order to obtain long conjugated polymers able to give high non-linear optical hyperpolarizabilities. Here we report the synthesis of such monomers incorporating cholesteryl and methoxybiphenyl groups; their structural and thermal behaviour are described. The occurrence of mesophases in the acetylenic and diacetylenic derivatives is discussed as a function of the spacer length and of the size of the mesogen moiety. The diacetylenic derivatives containing the methoxybiphenyl groups do not exhibit any liquid-crystalline behaviour but are able to polymerize under U.V. radiation. 相似文献
130.
This paper develops a method for finding the whole set of efficient points of a multiobjective linear problem. Two algorithms are presented; the first one describes the set of all efficient vertices and all efficient rays of the constraint polyhedron, while the second one generates the set of all efficient faces. The method has been tested on several examples for which numerical results are reported.The authors are grateful to Professor W. Stadler and an anonymous referee for their helpful comments and corrections. 相似文献