103,895 research outputs found
e-Science and its implications
No full textAfter a definition of e-science and the Grid, the paper begins with an overview of the technological context of Grid developments. NASA’s Information Power Grid is described as an early example of a ‘prototype production Grid’. The discussion of e-science and the Grid is then set in the context of the UK e-Science Programme and is illustrated with reference to some UK e-science projects in science, engineering and medicine. The Open Standards approach to Grid middleware adopted by the community in the Global Grid Forum is described and compared with community based standardization processes used for the Internet, MPI, Linux and the Web. Some implications of the imminent data deluge that will arise from the new generation of e-science experiments in terms of archiving and curation are then considered. The paper concludes with remarks about social and technological issues posed by Grid enabled ‘collaboratories’ in both scientific and commercial contexts
Versatile Coordination Chemistry of Hexa- tert-butyl-octaphosphine
No full textThe octaphosphine {cyclo-(P4tBu3)}2 (1) possesses a multifaceted coordination chemistry. The predominant binding mode is a P,P-chelate, e.g., in the monometallic chelate complex [MLL′(1-κ2P2,P4′)] in which the ligand 1 adopts a gauche conformation. Examples include square-planar (M = RhI, L = CO, L′ = Cl (2), M = PdII, L = L′ = Cl (3), M = PtII, L = L′ = Cl (9)), tetrahedral (M = Co-I, L = NO, L′ = CO (4)), and trigonal-planar complexes [ML(1-κ2P2,P4′)] (M = Pd0, L = PPh3, (5), M = CuI, L = Br (6)). With 2 equiv of [CuBr(SMe2)], a dinuclear complex [(CuBr)2(1-κ2P2,P2′,κ2P4,P4′)] (7) was obtained which features a synperiplanar conformation of the octaphosphine. A second coordination mode was also observed in [PtCl2(1-κ2P1,P2′)] (10) in which the bridge phosphorus atom in octaphosphine 1 is involved in the chelation, with the ligand in an antiperiplanar conformation. Thermolysis of selected complexes showed them to be suitable candidates for the generation of phosphorus-rich metal phosphides MPx (x > 1)
Unser Lieblingselement: Phosphor
No full textDas Element zwischen Fluch und Segen feiert dieses Jahr den 350. Jahrestag seiner Entdeckung. Es entfacht nicht nur Streichhölzer, sondern war auch Bestandteil von Kampfstoffen. Ebenso vielseitig ist seine Chemie
Unexpected Isomerization of Hexa-tert-butyl-octaphosphane
No full textOctaphosphane {cyclo-(P4tBu3)}2 (1) undergoes an unexpected isomerization reaction to the constitutional isomer 2,2′,2′′,2′′′,3,3′-hexa-tert-butyl-bicyclo[3.3.0]octaphosphane (2) in the presence of Lewis acidic metal salts. The mechanism of this reaction is discussed and elucidated with DFT calculations. The results underline the fascinating similarity between phosphorus-rich and isolobal carbon compounds. The new bicyclic octaphosphane 2 shows a dynamic behavior in solution and reacts with [AuCl(tht)] (tht=tetrahydrothiophene) to give a mono- ([AuCl(2-κP3)], 3) and a dinuclear complex ([(AuCl)2(2-κP3,κP3′)], 4). With cis-[PdCl2(cod)] (cod=1,5-cyclooctadiene), the chelate complex ([PdCl2(2-κ2P2,P2′)], 5) with a different coordination mode of the ligand was obtained
e-Science and its implications for the library community
No full textExplains the nature of the ‘e-Science’ revolution in 21st century scientific research and its consequences for the library community.
The concepts of e-Science are illustrated by a discussion of the CombeChem, eBank and SmartTea projects. The issue of open access is then discussed with reference to arXiv, PubMed Central and EPrints. The challenges these trends present to the library community are discussed in the context of the TARDis project and the University of Southampton Research Repository.
Increasingly academics will need to collaborate in multidisciplinary teams distributed across several sites in order to address the next generation of scientific problems. In addition, new highthroughput devices, high resolution surveys and sensor networks will result in an increase in scientific data collected by several orders of magnitude. To analyze, federate and mine this data will require collaboration between scientists and computer scientists; to organize, curate and preserve this data will require collaboration between scientists and librarians. A vital part of the developing research infrastructure will be digital repositories containing both publications and data.
The paper provides a synthesis of e-Science concepts, the question of open access to the results of scientific research, and a changing attitude towards academic publishing and communication. The paper offers a new perspective on coming demands on the library and is of special interest to librarians with strategic tasks
Building Quality Assurance into Metadata Creation: an Analysis based on the Learning Objects and e-Prints Communities of Practice
No full textThis paper challenges some of the assumptions underlying the metadata creation process in the context of two communities of practice, based around learning object repositories and open e-Print archives. The importance of quality assurance for metadata creation is discussed and evidence from the literature, from the practical experiences of repositories and archives, and from related research and practices within other communities is presented. Issues for debate and further investigation are identified, formulated as a series of key research questions. Although there is much work to be done in the area of quality assurance for metadata creation, this paper represents an important first step towards a fuller understanding of the subject.
An Experimental Analysis of Optimal Renewable Resource Management: The Fishery
No full textExperimental economics, Renewable resources, Dynamic decision making, Decisions under risk and uncertainty, Misperceptions of feedback,
Catalogue of Meteorites G. T. Prior, Seconde édition revue par Max H. Hey, 1953
No full textJérémine Elisabeth. Catalogue of Meteorites G. T. Prior, Seconde édition revue par Max H. Hey, 1953. In: Bulletin de la Société française de Minéralogie et de Cristallographie, volume 77, 7-9, 1954. p. 1285
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
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