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991.
Andrea Ravasio Laura Boggioni Incoronata Tritto Cristina D'arrigo Angelo Perico Julia Hitzbleck Jun Okuda 《Journal of polymer science. Part A, Polymer chemistry》2009,47(21):5709-5719
The in situ synthesis of ethylene‐co‐norbornene copolymers/multi‐walled carbon nanotubes (MWNTs) nanocomposites was achieved by rare‐earth half‐sandwich scandium precursor [Sc(η5‐C5Me4SiMe3)(η1‐CH2SiMe3)2(THF)] (1) activated by [Ph3C][B(C6F5)4], through a non‐PFT (Polymerization Filling Technique) approach. MWNTs nanocomposites with low aluminum residue were obtained with excellent yields even though small amounts of triisobutylaluminium were needed as scavenger to prevent catalyst poisoning by MWNT impurities. MWNT bundles were disaggregated and highly coated with Poly(ethylene‐co‐norbornene) [P(E‐co‐N)] as revealed by transmission electron microscopy. Interestingly, P(E‐co‐N) copolymers showed Tg over 130 °C as well as norbornene content over 50 mol %; both values were higher than those obtained by the cationic active species in 1 /[Ph3C][B(C6F5)4]. A series of copolymerization reactions by 1 /[Ph3C][B(C6F5)4]/AliBu3 without MWNTs produced copolymers with the same unexpected features. The NMR analysis revealed the presence of rac‐ENNE and rac‐ENNNE sequences. Thus, AliBu3 changed the stereoirregular alternating copolymer microstructure produced by 1 /[Ph3C][B(C6F5)4]. We conclude that AliBu3 is not only a scavenger for CNT impurities, but it reacts with the THF ligand to give coordinatively unsaturated active species. Finally, P(E‐co‐N)/MWNT masterbatches were mixed with commercial TOPAS to produce cyclic olefin copolymer nanocomposites with excellent dispersion of filler. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5709–5719, 2009 相似文献
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Chiara Guarino Fabio Fuselli Alessandro La Mantia Lucia Longo Angelo Faberi Rosa Maria Marianella 《Rapid communications in mass spectrometry : RCM》2010,24(6):705-713
A common fraud in the dairy field is the addition of sheep's milk to goat's cheeses, because it has a very similar taste to goat's milk, but is more available, and is commonly considered to have a better capacity to curdle. For similar reasons, and due to economic convenience, sheep's cheeses may also contain fraudulent cow's milk. In order to detect this fraud, an EU official method may be used, but it is only a qualitative method (presence/absence of cow's milk). A method able to quantify the presence of sheep's milk during cheese production in goat's and cow's cheeses was developed. The method is based on liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI‐MS/MS) analysis of peptides of a casein extract from the cheese. By a simple procedure, caseins are extracted from cheeses, solubilized, digested with plasmin, and subsequently analyzed by LC/ESI‐MS/MS. A typical sheep's peptide produced by plasmin hydrolysis (m/z = 860) was accurately selected and analyzed to understand if, and by how much, a declared pure goat's cheese contains sheep's milk. By analyzing the same peptide it is also possible to detect if, and by how much, a declared pure sheep's milk contains, or not, cow's milk. The method was applied to several goat's and cow's cheese samples. Quantitation was performed with a calibration curve obtained by analyzing curd cheeses containing different percentages of sheep's milk. The method detection limit and method quantitation limit were evaluated. This method appears accurate and suitable for detecting up to 2% of sheep's milk in cheeses. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Renato M. Angelo 《Foundations of Physics》2009,39(2):109-119
The polemical term “interaction-free measurement” (IFM) is analyzed in its interpretative nature. Two seminal works proposing
the term are revisited and their underlying interpretations are assessed. The role played by nonlocal quantum correlations
(entanglement) is formally discussed and some controversial conceptions in the original treatments are identified. As a result
the term IFM is shown to be consistent neither with the standard interpretation of quantum mechanics nor with the lessons
provided by the EPR debate. 相似文献
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Motivated by a renewed interest in generalizations of classical almost periodicity (originally due to Harald Bohr), we develop
a theorem of Bochner within the framework of almost periodic functions in the sense of Stepanov. As a result we establish
some conditions that guarantee the existence of Stepanov almost periodic solutions to differential equations with Stepanov
almost periodic coefficients. Finally, we extend a now classic theorem of Favard originally stated for classical almost periodic
functions to the Stepanov almost periodic case.
相似文献
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