971 resultados para bridging


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Based on the electrostatic attraction Keggin-type polyoxometalate H4SiW12O40 (SiW12) and small molecule 4-aminobenzo-15-crown-5 ether (4-AB15C5) were alternately deposited on poly (allylamine hydrochloride) (PAH)-derived indium tin oxide (ITO) substrate through a layer-by-layer (LBL) self-assembly, forming a supramolecular multilayer film (film-A). SiW12 was also deposited on a glassy carbon electrode (GCE) derived by 4-AB15C5 via covalent bonding in 0.1 M NaCl aqueous solution and formed a composite monolayer film (film-B). UV-vis absorption spectroscopy, X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FTIR) spectroscopy measurements demonstrated that the interactions between SiW12 and 4-AB15C5 in both two film electrodes were the same and caused by the bridging action of oxonium ions. But, the nanostructure in the two film electrodes was different. 4-AB15C5 in film-A was oriented horizontally to ITO substrate, however, that in film-B was oriented vertically to GCE. Namely film-A corresponded to a layer structure, and film-B corresponded to an intercalation structure.

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The structure of the title compound, [Cu2Cl2(C12H10N2)](n), contains infinite CuCl staircase-like chains, which lie about inversion centres. The trans-1,2-di-4-pyrid-ylethyl-ene mol-ecules also lie about inversion centres and connect the CuCl chains through Cu-N coordination bonds into a two-dimensional organic-inorganic hybrid network. The planar sheets are stacked along the c axis and associated through weak C-H center dot center dot center dot Cl inter-actions. The results show a reliable structural motif with controllable separation of the CuCl chains by variation of the length of the ligand.

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Two novel organic-inorganic hybrid compounds, (H(2)enMe)(4)(H3O)[Ni(enMe)(2)].[Na3Mo12O52P8(OH)(10)].5H(2)O (1) and (H(2)enMe)(4)(H3O)[Cu(enMe)(2)].[Na3Mo12O52P8(OH)(10)].5H(2)O (2) (enMe = 1,2-diaminopropane), have been hydrothermally synthesized and characterized by elemental analyses, IR, EPR, XPS, UV-Vis spectra and TG analyses. Single crystal X-ray diffraction shows that 1 and 2 are isostructural compounds. Both the compounds exhibit an unusual two-dimensional (2-D) window-like network consisting of one-dimensional (1-D) chains of sodium molybdenum phosphate anions connected by transition metal coordination complexes cations. Compound 1 and 2 represent the first 2-D molybdenum phosphate skeleton pillared by transition metal complex fragments.

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Three prototypes of dinuclear complexes were obtained from the reactions of dilithium 1,2-dicarbacloso-dodecaborane-1,2-dichalcogenolates, (B10H10)C-2-(ELi)(2) (E = S, Se), with CpFe(CO)(2)Cl (1), CpRu(PPh3)(2)Cl (2), or [Cp*RuCl2](2) (3), respectively, and their structures have been determined by X-ray crystallography.

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Three bridging ligands (L) and their binuclear phenanthroline ruthenium(II) complexes {[Ru(1,10-phenanthroline)(2)](2)(L)}(PF6)(4) were synthesized and characterized by IR, H-1 NMR, and elemental analysis, where L are 1,8-adipoylamido-bis(1,10-phenanthroline-5-yl) (L-1), 1,11-azelaoylamidobis(1, 10-phenanthroline-5-yl) (L-2), and p-phthaloylamido-bis(1,10-phenanthroline-5-yl) (L-3).

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An organic-inorganic hybrid solid, (Cu(2,2'-bpy)(2))(2)Mo8O26, has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Dark green crystals crystallize in the orthorhombic system, space group Pna21, a = 24.164(5), b = 18.281(4), c = 11.877(2) Angstrom, alpha = 90 degrees, beta = 90 degrees, gamma = 90 degrees, V= 5247(2) Angstrom (3), Z = 4, lambda (MoK alpha) = 0.71073 Angstrom (R(F) = 0.0331 for 5353 reflections). Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range 1.69 degrees < theta < 25.04 degrees using the omega -scan technique. The structure was solved by the direct method and refined by full-matrix least squares on F-2 using SHELXL-93. The structure of this compound consists of discrete (Cu(2,2'-bpy)(2))(2)Mo8O26 clusters, constructed from beta -octamolybdate subunits ((Mo8O26)(4-)) covalently bonded to two (Cu(2,2'-bpy)(2))(2+) coordination complexes via bridging oxo groups that connect two adjacent molybdenum sites. (C) 2001 Academic Press.

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In this paper, we viewed the diel vertical migration (DVM) of copepod in the context of the animal's immediate behaviors of everyday concerns and constructed an instantaneous behavioral criterion effective for DVM and non-DVM behaviors. This criterion employed the function of 'venturous revenue' (VR), which is the product of the food intake and probability of the survival, to evaluate the gains and losses of the behaviors that the copepod could trade-off. The optimal behaviors are to find the optimal habitats to maximize VR. Two types of VRs are formulated and tested by the theoretical analysis and simulations. The sensed VR, monitoring the real-time changes of trade-offs and thereby determining the optimum habitat, is validated to be the effective objective function for the optimization of the behavior; whereas, the realized VR, quantifying the actual profit obtained by an optimal copepod in the sensed-VR-determined habitat, defines the life history of a specific age cohort. The achievement of a robust copepod overwintering stock through integrating the dynamics of the constituent age cohorts subjected to the instantaneous behavioral criterion for DVM clearly exemplified a possible way bridging the immediate pursuit of an individual and the end success of the population. (c) 2005 Published by Elsevier Ltd.

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In conservatories and music schools, the general practice for an aspiring pianist is to focus on solo performance learning mainly solo repertoire. With the advent of the advanced degree in collaborative piano, pianists could submerge themselves in the study of duo sonatas, larger chamber music ensembles, and art song. The appearance of this degree was an important step in the development of pianists, as this kind of work requires specific training and focus to master the vast repertoire involved. However it also more clearly brought out the invisible divide separating the solo pianist from the collaborative pianist, a.k.a. the accompanist. While geniuses such as Bach, Beethoven and Brahms were known to compose and perform all types of music, the appearance of super stars such as Liszt and Paganini helped bring into being the term accompanist and since then music world has tacitly embraced this divide. The goal of my dissertational study is to show that this divide need not exist. The three recitals which comprise this dissertational project were all performed at the University of Maryland, the first on 12 November 2010 at Gildenhom Recital Hall, the second at Ulrich Recital Hall on 10 September 2011, and the third at Gildenhorn Recital Hall on 11 November 2011. The repertoire included Rachmaninoff Prelude in g# minor op. 32 no. 12 and Etude-Tableaux in Eb minor op. 29 no. 5, Brahms Sonata for Piano and Violin in d minor op. 108, Mendelssohn Piano Trio in d minor op. 49, Chopin Sonata No.2 in Bb minor, Franck Sonata for Piano and Violin, Prokofiev Piano Concerto no. 2 in g minor op. 16 with pianist Elizabeth Brown as orchestra, Beethoven Sonata for Piano and Violin in A op 47 (Kreutzer), and Paul Schoenfield Cafe Music. All works with violin and cello were performed with violinist Rebecca Racusin, and cellist Devree Lewis. The recitals were recorded on compact discs and are archived within the Digital Repository at the University of Maryland(DRUM).

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Research supervision in the field of counselling and psychotherapy is a fruitful area for investigation in view of the fact that the research supervisory relationship is powerful and highly charged, whether consciously acknowledged or not. Researchers trained as counsellors and psychotherapists possess the skills to facilitate the emergence of, and work creatively with, impasses and crises, both in the research itself and the supervisory relationship, as a result of their training and experience in dealing with crisis and catharsis in clinical work. This paper will demonstrate these points using a case vignette from my work as a supervisor of research dissertations undertaken by students on a Masters in Therapeutic Counselling course. Drawing on narrative analysis, clinical supervision theory and discursive analysis it will look at the strengths and weaknesses of a 'psychotherapeutic' approach to research supervision.

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Collaborative approaches in leadership and management are increasingly acknowledged to play a key role in successful institutions in the learning and skills sector (LSS) (Ofsted, 2004). Such approaches may be important in bridging the potential 'distance' (psychological, cultural, interactional and geographical) (Collinson, 2005) that may exist between 'leaders' and 'followers', fostering more democratic communal solidarity. This paper reports on a 2006-07 research project funded by the Centre for Excellence in Leadership (CEL) that aimed to collect and analyse data on 'collaborative leadership' (CL) in the learning and skills sector. The project investigated collaborative leadership and its potential for benefiting staff through trust and knowledge-sharing in communities of practice (CoPs). The project forms part of longer-term educational research investigating leadership in a collaborative inquiry process (Jameson et al., 2006). The research examined the potential for CL to benefit institutions, analysing respondents' understanding of and resistance to collaborative practices. Quantitative and qualitative data from senior managers and lecturers was analysed using electronic data in SPSS and Tropes Zoom. The project aimed to recommend systems and practices for more inclusive, diverse leadership (Lumby et al., 2005). Collaborative leadership has increasingly gained international prominence as emphasis shifted towards team leadership beyond zero-sum 'leadership'/ 'followership' polarities into more mature conceptions of shared leadership spaces, within which synergistic leadership spaces can be mediated. The relevance of collaboration within the LSS has been highlighted following a spate of recent government-driven policy developments in FE. The promotion of CL addresses concerns about the apparent 'remoteness' of some senior managers, and the 'neo-management' control of professionals which can increase 'distance' between leaders and 'followers' and may de-professionalise staff in an already disempowered sector. Positive benefit from 'collaborative advantage' tends to be assumed in idealistic interpretations of CL, but potential 'collaborative inertia' may be problematic in a sector characterised by rapid top-down policy changes and continuous external audit and surveillance. Constant pressure for achievement against goals leaves little time for democratic group negotiations, despite the desires of leaders to create a more collaborative ethos. Yet prior models of intentional communities of practice potentially offer promise for CL practice to improve group performance despite multiple constraints. The CAMEL CoP model (JISC infoNet, 2006) was linked to the project, providing one practical way of implementing CL within situated professional networks.The project found that a good understanding of CL was demonstrated by most respondents, who thought it could enable staff to share power and work in partnership to build trust and conjoin skills, abilities and experience to achieve common goals for the good of the sector. However, although most respondents expressed agreement with the concept and ideals of CL, many thought this was currently an idealistically democratic, unachievable pipe dream in the LSS. Many respondents expressed concerns with the 'audit culture' and authoritarian management structures in FE. While there was a strong desire to see greater levels of implementation of CL, and 'collaborative advantage' from the 'knowledge sharing benefit potential' of team leadership, respondents also strongly advised against the pitfalls of 'collaborative inertia'. A 'distance' between senior leadership views and those of staff lower down the hierarchy regarding aspects of leadership performance in the sector was reported. Finally, the project found that more research is needed to investigate CL and develop innovative methods of practical implementation within autonomous communities of professional practice.

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Exploring climate and anthropogenic impacts on marine ecosystems requires an understanding of how trophic components interact. However, integrative end-to-end ecosystem studies (experimental and/or modelling) are rare. Experimental investigations often concentrate on a particular group or individual species within a trophic level, while tropho-dynamic field studies typically employ either a bottom-up approach concentrating on the phytoplankton community or a top-down approach concentrating on the fish community. Likewise the emphasis within modelling studies is usually placed upon phytoplankton-dominated biogeochemistry or on aspects of fisheries regulation. In consequence the roles of zooplankton communities (protists and metazoans) linking phytoplankton and fish communities are typically under-represented if not (especially in fisheries models) ignored. Where represented in ecosystem models, zooplankton are usually incorporated in an extremely simplistic fashion, using empirical descriptions merging various interacting physiological functions governing zooplankton growth and development, and thence ignoring physiological feedback mechanisms. Here we demonstrate, within a modelled plankton food-web system, how trophic dynamics are sensitive to small changes in parameter values describing zooplankton vital rates and thus the importance of using appropriate zooplankton descriptors. Through a comprehensive review, we reveal the mismatch between empirical understanding and modelling activities identifying important issues that warrant further experimental and modelling investigation. These include: food selectivity, kinetics of prey consumption and interactions with assimilation and growth, form of voided material, mortality rates at different age-stages relative to prior nutrient history. In particular there is a need for dynamic data series in which predator and prey of known nutrient history are studied interacting under varied pH and temperature regimes.

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Meeting the world’s energy demand is a major challenge for society over the coming century. To identify the most sustainable energy pathways to meet this demand, analysis of energy systems on which policy is based must move beyond the current primary focus on carbon to include a broad range of ecosystem services on which human well-being depends. Incorporation of a broad set of ecosystem services into the design of energy policy will differentiates between energy technology options to identify policy options that reconcile national and international obligations to address climate change and the loss of biodiversity and ecosystem services. In this paper we consider our current understanding of the implications of energy systems for ecosystem services and identify key elements of an assessment. Analysis must consider the full life cycle of energy systems, the territorial and international footprint, use a consistent ecosystem service framework that incorporates the value of both market and non-market goods, and consider the spatial and temporal dynamics of both the energy and environmental system. While significant methodological challenges exist, the approach we detail can provide the holistic view of energy and ecosystem services interactions required to inform the future of global energy policy.

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