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941.
Francesco Caruso Steven Saverwyns Marina Van Bos Delia Francesca Chillura?Martino Anne-Emmanuelle Ceulemans Joris de Valck Eugenio Caponetti 《Applied Physics A: Materials Science & Processing》2012,107(1):197-202
In recent years, a growing attention has been addressed to the study of the varnish from early musical instruments. The surfaces
of nine historical Low Countries stringed musical instruments from the collection of the “Musical Instruments Museum” in Brussels
were non-destructively analysed by in situ micro-X-Ray Fluorescence spectroscopy in dispersive mode. It was found that the
main pigments dispersed in the varnish were iron- and manganese-based earths. The presence of a chromium-based pigment in
one of the analysed instruments makes it appreciably different from the others. Other findings were discussed and compared
with previously published results. The collection of such information plays a relevant role in the recovery of the applied
formulations that is an interesting issue for conservators, luthiers and art historians. 相似文献
942.
Estradé S Portillo J Mendoza J Kosta I Serret M Müller C Peiró F 《Micron (Oxford, England : 1993)》2012,43(8):910-915
Precession electron diffraction (PED) allows for diffraction pattern collection under quasi-kinematical conditions. The combination of PED with fast electron diffraction acquisition and pattern matching software techniques is used for the high magnification ultra-fast mapping of variable crystal orientations and phases, similarly to what is achieved with the Electron Backscattered Diffraction technique in Scanning Electron Microscopes at lower magnifications and longer acquisition times. Here we report, for the first time, the application of this PED-based orientation mapping technique to both metallic and semiconducting nanowires. 相似文献
943.
Highly stable gel electrolytes for dye solar cells based on chemically engineered polymethacrylic hosts 总被引:1,自引:0,他引:1
De Gregorio GL Agosta R Giannuzzi R Martina F De Marco L Manca M Gigli G 《Chemical communications (Cambridge, England)》2012,48(25):3109-3111
Four different species of ionically conductive polymers were synthesized and successfully implemented to formulate novel quasi-solid electrolytes for dye solar cells. A power conversion efficiency superior to 85% of the correspondent liquid electrolyte as well as an excellent cell's stability was demonstrated after 500 days of storage. 相似文献
944.
945.
Francesca Cagliari Maria Manuel Clementino Sandra Mantovani 《Journal of Pure and Applied Algebra》2012,216(11):2411-2424
Using Escardó’s characterization of injectivity via Kock–Zöberlein monads, we introduce suitable monads in comma categories of topological spaces that yield characterizations of fibrewise injectivity in topological T0-spaces, with respect to the class of embeddings, and of dense, of flat and of completely flat embeddings. Characterizations, in the category of topological spaces, of injective maps with respect to the same classes of embeddings follow easily from the results obtained for T0-spaces. Moreover, it is shown that, together with the corresponding embeddings, injective continuous maps form a weak factorization system in the category of topological (T0-)spaces and continuous maps. 相似文献
946.
947.
948.
Detto F Armani N Lazzarini L Toccoli T Verucchi R Aversa L Nardi MV Rossi B Salviati G Iannotta S 《Physical chemistry chemical physics : PCCP》2012,14(16):5705-5710
Unprecedented room temperature excitonic emissions are achieved from TiO(2) nanocrystals synthesized at 300 K by supersonic cluster beams. Transmission electron microscopy studies show the crystalline nature of the nanoparticles (NPs) with a diameter ranging from 5 to 30 nm. All the samples show mixed rutile and anatase phases as confirmed by Raman spectroscopy. XPS core level analyses evidence an O/Ti ratio of the as-grown nanoparticles of 2.30 ± 0.04. Two room temperature cathodoluminescence excitonic peaks observed at 3.16 and 3.25 eV are ascribed to the coexistence of rutile and anatase crystallographic phases respectively. Subsequent thermal treatments at 450 °C cause the complete quenching of the UV excitonic emissions and result in a more conventional broad visible band centered at 2.5 eV. HRTEM and XPS studies reveal that, after annealing, the NPs remain single crystals in nature with an O/Ti ratio of 2.20 ± 0.04. These results suggest a correlation between the emission properties and the oxygen concentration of our NPs. The achieved ability to tune the optical properties of TiO(2) nanoparticles is very promising for sensing and energy applications. 相似文献
949.
In this paper, numeration systems defined by recurrent sequences are considered. We present a class of recurrences yielding numeration systems for which the words corresponding to greedy expressions for natural numbers are easily described. Those sequences, in turn, enumerate classes of words with forbidden substrings. 相似文献
950.
The kinetics of the rearrangement of the Z-phenylhydrazone of 3-benzoyl-5-phenyl-1,2,4-oxadiazole (1) into the relevant 4-benzoylamino-2,5-diphenyl-1,2,3-triazole (2) induced by amines have been studied in five room-temperature ionic liquids (RTILs) at different temperatures. The kinetic data collected show that both cationic and anionic parts of RTILs significantly influence the reactivity of the title reaction. The calculated activation parameters allow us to advance hypotheses about the weak interactions operating in RTIL solutions. 相似文献