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Marcel Stangl Jörg Acker Volker Hoffmann Wolfgang Gruner Klaus Wetzig 《Mikrochimica acta》2006,156(1-2):159-162
This article presents investigations regarding the incorporation of organic impurities in thin electroplated Cu metallizations.
RF-GD-OES (radio frequency glow discharge optical emission spectrometry) was used for detection of C and H as indicators for
incorporated hydrocarbon molecules. The presented results indicate a fragmentation of incorporated hydrocarbons and their
constrict segregation near the Cu surface. The bilateral relationship between incorporated organic impurities and intrinsic
stress behavior is associated with the Gorky effect. 相似文献
995.
Marcel Goic Máximo Bosch Juan P Castro 《The Journal of the Operational Research Society》2015,66(1):160-171
Growth in operational complexity is a worldwide reality in the retail industry. One of the most tangible expressions of this phenomenon is the vast increase in the number of products offered. To cope with this problem, the industry has developed the ‘category management’ approach, in which groups of products with certain common characteristics are grouped together into ‘categories’, managed as if they were independent business units. In this paper, we propose a model to evaluate relative category performance in a retail store, considering they might have different business objectives. Our approach is based on Data Envelopment Analysis techniques and requires a careful definition of the resources that categories use to contribute to achieving their business objectives. We illustrate how to use our approach by applying it to the evaluation of several categories in a South American supermarket. The empirical results show that, even for very conservative assumptions, the model has a significant discriminatory power, identifying 25% of the sample as not operating efficiently. Although efficiency scores might exhibit a relatively large dispersion, the set of efficient units is robust to data variations. 相似文献
996.
Controlling the Shape of Evaporating Droplets by Ionic Strength: Formation of Highly Anisometric Silica Supraparticles
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Marcel Sperling Prof. Dr. Orlin D. Velev Prof. Dr. Michael Gradzielski 《Angewandte Chemie (International ed. in English)》2014,53(2):586-590
Anisometric silica supraparticles are produced by a simple process of evaporation of sessile droplets containing fumed silica deposited on a superhydrophobic substrate. The shape of the supraparticles is directly controlled by the salt (NaCl) concentration, becoming anisometric beyond a threshold concentration, as quantified by light microscopy. This process is easily extended to supraparticles containing further functional colloidal components. 相似文献
997.
Ricardo?Couso-Santamaría José?D.?Edelstein Ricardo?SchiappaEmail author Marcel?Vonk 《Communications in Mathematical Physics》2015,335(1):285-307
The holomorphic anomaly equations describe B-model closed topological strings in Calabi–Yau geometries. Having been used to construct perturbative expansions, it was recently shown that they can also be extended past perturbation theory by making use of resurgent transseries. These yield formal nonperturbative solutions, showing integrability of the holomorphic anomaly equations at the nonperturbative level. This paper takes such constructions one step further by working out in great detail the specific example of topological strings in the mirror of the local \({\mathbb{C}\mathbb{P}^2}\) toric Calabi–Yau background, and by addressing the associated (resurgent) large-order analysis of both perturbative and multi-instanton sectors. In particular, analyzing the asymptotic growth of the perturbative free energies, one finds contributions from three different instanton actions related by \({\mathbb{Z}_3}\) symmetry, alongside another action related to the Kähler parameter. Resurgent transseries methods then compute, from the extended holomorphic anomaly equations, higher instanton sectors and it is shown that these precisely control the asymptotic behavior of the perturbative free energies, as dictated by resurgence. The asymptotic large-order growth of the one-instanton sector unveils the presence of resonance, i.e., each instanton action is necessarily joined by its symmetric contribution. The structure of different resurgence relations is extensively checked at the numerical level, both in the holomorphic limit and in the general nonholomorphic case, always showing excellent agreement with transseries data computed out of the nonperturbative holomorphic anomaly equations. The resurgence relations further imply that the string free energy displays an intricate multi-branched Borel structure, and that resonance must be properly taken into account in order to describe the full transseries solution. 相似文献
998.
Corina Cheptea Valeriu Sunel Jacques Desbrieres Marcel Popa 《Journal of heterocyclic chemistry》2013,50(2):366-372
The synthesis of new derivatives of 1,3,4‐thiadiazoles and 1,2,4‐triazoles was achieved using the 1,4‐disubstituted thiosemicarbazides as intermediaries. 相似文献
999.
Abstract The well-known tricyclic sesquiterpenoid (?)-sativene, isolated in 1965 from Helminthosporium sativum and shown to possess structure and absolute configuration as indicated by structure 1 3, has been implicated3,4 as an intermediate in the biogenesis of the fungal toxin (?)-helminthosporal (2)5. Two total syntheses of the racemic modification of sativene have been reported6,7. A closely related sesquiterpenoid, (+)-cyclosativene, was isolated from Abies magnifica A. Murr. and was shown to possess structure 3 8,9. The absolute configuration of this material, although not established unambiguously, has been proposed10 as indicated by formula 3. The total synthesis of cyclosativene has not as yet been achieved directly, although it has been obtained indirectly via acid-promoted rearrangement of sativene8,9,11,12. We report herein a total synthesis of (+)-sativene (4) and (+)-cyclosativene (3) via a stereoselective route which unambiguously establishes the absolute configuration of both natural products. 相似文献
1000.