343,210 research outputs found
Fluorescent Silicon Clusters and Nanoparticles
The fluorescence of silicon clusters is reviewed. Atomic clusters of silicon
have been at the focus of research for several decades because of the relevance
of size effects for material properties, the importance of silicon in
electronics and the potential applications in bio-medicine. To date numerous
examples of nanostructured forms of fluorescent silicon have been reported.
This article introduces the principles and underlying concepts relevant for
fluorescence of nanostructured silicon such as excitation, energy relaxation,
radiative and non-radiative decay pathways and surface passivation.
Experimental methods for the production of silicon clusters are presented. The
geometric and electronic properties are reviewed and the implications for the
ability to emit fluorescence are discussed. Free and pure silicon clusters
produced in molecular beams appear to have properties that are unfavourable for
light emission. However, when passivated or embedded in a suitable host, they
may emit fluorescence. The current available data show that both quantum
confinement and localised transitions, often at the surface, are responsible
for fluorescence. By building silicon clusters atom by atom, and by embedding
them in shells atom by atom, new insights into the microscopic origins of
fluorescence from nanoscale silicon can be expected.Comment: 5 figures, chapter in "Silicon Nanomaterials Sourcebook", editor
Klaus D. Sattler, CRC Press, August 201
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Genetic algorithm approach to find the best input variable partitioning
Conference PaperThis paper presents a variable partition algorithm which combines the quasi-reduced ordered multiple-terminal multiple-valued decision diagrams and genetic algorithms (GAs). The algorithm is better than the previous techniques which find a good functional decomposition by non-exhaustive search and expands the range of searching for the best decomposition providing the optimal subtable multiplicity. The possible solutions are evaluated using the gain of decomposition for a multiple-output multiple-valued logic function. The distinct feature of GA is the possible solutions being coded by real numbers. Here the simplex-based crossover is proposed to use for the recombination stage of GA. It permits to increase the GA coverag
Special Libraries, February 1924
Volume 15, Issue 2https://scholarworks.sjsu.edu/sla_sl_1924/1001/thumbnail.jp
Musik und Film : Hilfsmittel, Lexika, Verzeichnisse
Inhalt: 1. Bibliographien 2. Musikographien, Diskographien, Filmographien 3. Biographica, Werkverzeichnisse, Personenlexik
Special Libraries, February 1924
Volume 15, Issue 2https://scholarworks.sjsu.edu/sla_sl_1924/1001/thumbnail.jp
The SIMBAD astronomical database
Simbad is the reference database for identification and bibliography of
astronomical objects. It contains identifications, `basic data', bibliography,
and selected observational measurements for several million astronomical
objects. Simbad is developed and maintained by CDS, Strasbourg. Building the
database contents is achieved with the help of several contributing institutes.
Scanning the bibliography is the result of the collaboration of CDS with
bibliographers in Observatoire de Paris (DASGAL), Institut d'Astrophysique de
Paris, and Observatoire de Bordeaux. When selecting catalogues and tables for
inclusion, priority is given to optimal multi-wavelength coverage of the
database, and to support of research developments linked to large projects. In
parallel, the systematic scanning of the bibliography reflects the diversity
and general trends of astronomical research.
A WWW interface to Simbad is available at: http://simbad.u-strasbg.fr/SimbadComment: 14 pages, 5 Postscript figures; to be published in A&A
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