1,630 research outputs found

    Deceleration of the solar wind in the Earth foreshock region: ISEE 2 and IMP 8 observations

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    The deceleration of the solar wind in the region of the interplanetary space filled by ions backstreaming from the Earth bow shock was studied using a two spacecraft technique. This deceleration, which is correlated with the "diffuse" but not with the "reflected" ion population, depends on the solar wind bulk velocity: at low velocities (below 300 km/sec) the velocity decrease is about 5 km/sec, while at higher velocities (above 400 km/sec) the decrease may be as large as 30 km/sec. Along with this deceleration, the solar wind undergoes a deflection of about 1 deg away from the direction of the Earth bow shock. The energy balance shows that the kinetic energy loss far exceeds the thermal energy which is possibly gained by the solar wind, therefore, at least part of this energy must go into waves and/or into the backstreaming ions

    Origin of the Exclusive Ternary Electroluminescent Behavior of BN‐Doped Nanographenes in Efficient Single‐Component White Light‐Emitting Electrochemical Cells

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    White-light-emitting electrochemical cells (WLECs) still represent a significant milestone, since only a few examples with moderate performances have been reported. Particularly, multiemissive white emitters are highly desired, as a paradigm to circumvent phase separation and voltage-dependent emission color issues that are encountered following host:guest and multilayered approaches. Herein, the origin of the exclusive white ternary electroluminescent behavior of BN-doped nanographenes with a B3N3 doping pattern (hexa-perihexabenzoborazinocoronene) is rationalized, leading to one of the most efficient (approximate to 3 cd A(-1)) and stable-over-days single-component and single-layered WLECs. To date, BN-doped nanographenes have featured blue thermally activated delayed fluorescence (TADF). This doping pattern provides, however, white electroluminescence spanning the whole visible range (x/y CIE coordinates of 0.29-31/0.31-38 and average color rendering index (CRI) of 87) through a ternary emission involving fluorescence and thermally activated dual phosphorescence. This temperature-dependent multiemissive mechanism is operative for both photo- and electroluminescence processes and holds over the device lifespan, regardless of the device architecture, active layer composition, and operating conditions. As such, this work represents a new stepping-stone toward designing a new family of multiemissive white emitters based on BN-doped nanographenes that realizes one of the best-performing single-component white-emitting devices compared to the prior-art

    Deep shower interpretation of the cosmic ray events observed in excess of the Greisen-Zatsepin-Kuzmin energy

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    We consider the possibility that the ultra-high-energy cosmic ray flux has a small component of exotic particles which create showers much deeper in the atmosphere than ordinary hadronic primaries. It is shown that applying the conventional AGASA/HiRes/Auger data analysis procedures to such exotic events results in large systematic biases in the energy spectrum measurement. SubGZK exotic showers may be mis-reconstructed with much higher energies and mimick superGZK events. Alternatively, superGZK exotic showers may elude detection by conventional fluorescence analysis techniques.Comment: 22 pages, 5 figure

    Successful private–public funding of paediatric medicines research: lessons from the EU programme to fund research into off-patent medicines

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    The European Paediatric Regulation mandated the European Commission to fund research on off-patent medicines with demonstrated therapeutic interest for children. Responding to this mandate, five FP7 project calls were launched and 20 projects were granted. This paper aims to detail the funded projects and their preliminary results. Publicly available sources have been consulted and a descriptive analysis has been performed. Twenty Research Consortia including 246 partners in 29 European and non-European countries were created (involving 129 universities or public funded research organisations, 51 private companies with 40 SMEs, 7 patient associations). The funded projects investigate 24 medicines, covering 10 therapeutic areas in all paediatric age groups. In response to the Paediatric Regulation and to apply for a Paediatric Use Marketing Authorisation, 15 Paediatric Investigation Plans have been granted by the EMAPaediatric Committee, including 71 studies of whom 29 paediatric clinical trials, leading to a total of 7,300 children to be recruited in more than 380 investigational centres. Conclusion: Notwithstanding the EU contribution for each study is lower than similar publicly funded projects, and also considering the complexity of paediatric research, these projects are performing high-quality research and are progressing towards the increase of new paediatric medicines on the market. Private–public partnerships have been effectively implemented, providing a good example for future collaborative actions. Since these projects cover a limited number of offpatent drugs and many unmet therapeutic needs in paediatrics remain, it is crucial foreseeing new similar initiatives in forthcoming European funding programmes

    The Power Manager for the LHCb On-Line Farm

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    The Power Manager is a tool of the LHCb FMC (Farm Monitoring and Control System) which allows - in an OS-independent manner and without requiring expensive network-controlled power distributors - to switch the farm nodes on and off, and to monitor their physical condition: power status (on/off), temperatures, fan speeds and voltages. The Power Manager can operate on farm nodes whose motherboards and network interface cards implement the IPMI (Intelligent Platform Management Interface) specifications, version 1.5 or subsequent, and copes with several IPMI limitations

    The Process Controller for the LHCb On-LIne Farm

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    The Process Controller is a tool of the LHCb FMC (Farm Monitoring and Control System) in charge of keeping a list of applications up and running on the farm nodes. It tipically runs on a few control PCs each one watching ~200 farm nodes and performs its task by maintaining the list of scheduled applications for each controlled farm node and by interacting with the Task Manager Servers running on the farm nodes to start processes, to obtain the notification of process termination, to re-spawn the terminated processes (if requested) and to stop processes. Processes can be added to or removed from the scheduled application list for one or more nodes by means of DIM commands, while DIM services provide the list of scheduled applications for each controlled farm node together with their properties, the number of re-spawns and the re-spawn times

    Direction-dependent secondary bonds and their stepwise melting in a uracil-based molecular crystal studied by infrared spectroscopy and theoretical modeling

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    Three types of supramolecular interactions are identified in the three crystallographic directions in crystals of 1,4-bis[(1-hexylurac-6-yl)ethynyl]benzene, a uracil-based molecule with a linear backbone. These three interactions, characterized by their strongest component, are: intermolecular double H-bonds along the molecular axis, London dispersion interaction of hexyl chains connecting these linear assemblies, and π\pi--π\pi stacking of the aromatic rings perpendicular to the molecular planes. On heating, two transitions happen, disordering of hexyl chains at 473 K, followed by H-bond melting at 534 K. The nature of the bonds and transitions was established by matrix-isolation and temperature-dependent infrared spectroscopy and supported by theoretical computations

    Two-dimensional core–shell donor–acceptor assemblies at metal–organic interfaces promoted by surface-mediated charge transfer

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    Organic charge transfer (CT) complexes obtained by combining molecular electron donors and acceptors have attracted much interest due to their potential applications in organic opto-electronic devices. In order to work, these systems must have an electronic matching – the highest occupied molecular orbital (HOMO) of the donor must couple with the lowest unoccupied molecular orbital (LUMO) of the acceptor – and a structural matching, so as to allow direct intermolecular CT. Here it is shown that, when molecules are adsorbed on a metal surface, novel molecular organizations driven by surface-mediated CT can appear that have no counterpart in condensed phase non-covalent assemblies of donor and acceptor molecules. By means of scanning tunneling microscopy and spectroscopy it is demonstrated that the electronic and self-assembly properties of an electron acceptor molecule can change dramatically in the presence of an additional molecular species with marked electron donor character, leading to the formation of unprecedented core–shell assemblies. DFT and classical force-field simulations reveal that this is a consequence of charge transfer from the donor to the acceptor molecules mediated by the metallic substrate

    Dysprosium-carboxylate nanomeshes with tunable cavity size and assembly motif through ionic interactions

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    We report the design of dysprosium directed metallo-supramolecular architectures on a pristine Cu(111) surface. By an appropriate selection of the ditopic molecular linkers equipped with terminal carboxylic groups (TPA, PDA and TDA species), we create reticular and mononuclear metal–organic nanomeshes of tunable internodal distance, which are stabilized by eight-fold Dy⋯O interactions. A thermal annealing treatment for the reticular Dy:TDA architecture gives rise to an unprecedented quasi-hexagonal nanostructure based on dinuclear Dy clusters, exhibiting a unique six-fold Dy⋯O bonding motif. All metallo-supramolecular architectures are stable at room temperature. Our results open new avenues for the engineering of supramolecular architectures on surfaces incorporating f-block elements forming thermally robust nanoarchitectures through ionic bonds
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