113,348 research outputs found
Tra oriente e occidente: città e iconografia dal XV al XIX secolo
No full texttesti di: G. Mangani, L. Nuti, F. I. Apolollonio, P. Clerici Maestosi, B. Marin, D. Stroffolino, M. Iuliano, A. Buccaro, L. Di Mauro, P. Miltenov, H. Jinnai, I. Principe, F. Marias, F,Pereda, F. Capano,I. Rosa, M. Iaccarino, F. Fiorani, M.B. Bettazzi, G. Mazz
Recensione a H. Schneider, Chronologisch-thematisch Verzeichnis sämtlicher Werke von Daniel François Esprit Auber (AWV)
No full textELECTRONIC-STRUCTURE OF A-SI1-XCX-H ALLOYS
No full textThe valence band states of a-Si1-xCx:H have been studied by combining photoemission and Auger spectroscopies. It was possible to establish the relative positions of the onsets and of the maxima of the local electronic-state density at C and Si atoms. It was also found that heteronuclear Si-C bonds are strongly favoured
Composite Cu-LaFeO3 conversion coatings on a 18Cr ferritic stainless steel for IT-SOFC interconnects: Effect of long-term air exposure at 700◦C on Cr diffusion barrier and electrical properties
No full textIn our previous study copper oxide additions were used to accelerate the formation of perovskite LaFeO3 conversion coatings on stainless steels from molten carbonate baths. Incorporation of copper particles into the growing coating was an additional effect resulting in the formation of a composite Cu-LaFeO3 structure. In continuation to our previous study, the aim of this work is to report the effect of copper additions on long-term stability and performance of perovskite conversion coatings under IT-SOFC interconnect conditions. To this end, a Cu-LaFeO3 coated K41 18Cr ferritic stainless steel was examined in air at 700◦C up to 1000 h. In order to simulate properly the situation of a real IT-SOFC cell, Area Specific Resistance (ASR) and Cr-barrier properties of the coated steel were evaluated simultaneously with a special coating characterization setup. Studies were conducted by comparison with single-phase LaFeO3 coatings obtained in a molten carbonate bath similar to that used for the formation of the composite Cu-LaFeO3 coatings but without the addition of copper oxide. Copper addition did not change the general morphology of the perovskite coating, which remains a multi-layer coating, being composed of an outer LaFeO3 crystalline layer, a middle Fe-rich oxide and two inner Fe-Cr rich oxide layers. However, copper was beneficial in promoting a thinner and more stable coating structure along with finer perovskite grain size. These structural improvements were further confirmed by the results obtained with electrical measurements that showed a better ASR behavior of the Cu-LaFeO3 coatings. On the other hand, no relevant copper effects could be detected on the coating oxidation stability and on the Cr-barrier properties of the perovskite conversion coatings. Both LaFeO3 and Cu-LaFeO3 coatings showed similarly high coating stability and excellent Cr-barrier capability in experiments conducted at 700◦C up to 1000 h. In definitive, dual-phase Cu-LaFeO3 seem more promising systems for IT-SOFC interconnects than single-phase LaFeO3 conversion coatings, although further improvements in ASR electrical properties are needed. © The Author(s) 2018
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
DISTRIBUTION OF OCCUPIED STATES IN A-C-H AND A-SI1-XCX-H ALLOYS AS DETERMINED BY TOTAL YIELD SPECTROSCOPY
No full textThe density of occupied states at the valence band edge and in the pseudo-gap is investigated by using Total yield spectroscopy. It is found that close to the valence band edge the yield spectra follow a (h-nu - E(v))3/(h-nu)2 dependence. A large increase of gap state density with increasing carbon content is also found
Growth of thin C60 films on hydrogenated Si (100) surfaces
No full textPhotoemission spectroscopies and atomic force microscopy (AFM) were performed on C-60 evaporated on the monohydride Si (100):H-(2 x 1) surface at different temperatures from room temperature up to 900 degrees C. X-ray photoelectron spectroscopy has revealed that the interaction is with the hydrogenated surface only for temperatures below 250 degrees C. Above this temperature the hydrogen starts to desorb and C-60 interacts directly with the clean silicon surface. The bond between C-60 and the Si(100):H-(2 x 1) surface is van der Waals' in character and is estimated to be of the same order of magnitude or even weaker than the C-60-C-60 interaction. AFM analysis was performed on multilayer samples grown in the range between room temperature and 200 degrees C. Room-temperature samples exhibit small Cs, islands. The order of the islands improves strongly when the temperature of the substrate is increased up to 200 degrees C. At this temperature the islands are all ordered with the hexagonal shape typical of C60 growth along the (111) direction and a lateral size of about 3000 Angstrom. (C) 2000 Elsevier Science B.V. All rights reserved
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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