We have observed emission from singlet and triplet exciplexes in electron donor (D)–acceptor (A) organic electroluminescent systems. The exciplex singlet-to-triplet fraction appears to be a function ...of electronic properties of the (D–A) complex molecular components and applied electric field. The fluorescence from exciplex singlets could be eliminated using a heavy atom (Gd)-substituted acceptor molecule allowing the efficient intersystem crossing of singlet into triplet exciplex states. By this a pure exciplex electrophosphorescent diode has been realized. These findings are of importance for the understanding of the exciplex formation mechanism and, thus, for material choice in device applications.
The genome sequence of Corynebacterium glutamicum, a gram-positive soil bacterium widely used as an amino acid producer, was analyzed by a similarity-based approach to elucidate the pathway for the ...biosynthesis of L-methionine. The functions of candidate ORFs were derived by gene deletion and, if necessary, by homologous complementation of suitable mutants. Of nine candidate ORFs (four of which were known previously), seven ORFs (cg0754 (metX), cg0755 (metY), cg1290 (metE), cg1702 (metH), cg2383 (metF), cg2536 (aecD), and cg2687 (metB)) were demonstrated to be part of the pathway while two others (cg0961 and cg3086) could be excluded. C. glutamicum synthesizes methionine in three, respectively four steps, starting from homoserine. C. glutamicum possesses two genes with similarity to homoserine acetyltransferases but only MetX can act as such while Cg0961 catalyzes a different, unknown reaction. For the incorporation of the sulfur moiety, the known functions of MetY and MetB could be confirmed and AecD was proven to be the only functional cystathionine beta-lyase in C. glutamicum, while Cg3086 can act neither as cystathionine gamma-synthase nor as cystathionine beta-lyase. Finally, MetE and MetH, which catalyze the conversion of L-homocysteine to L-methionine, could be newly identified, together with MetF which provides the necessary N(5)-methyltetrahydrofolate.
Prospects for observation of scalar gluons (sgluons) and Dirac gluinos, as predicted by the hybrid N = 1/N = 2 supersymmetric model, at the CERN Large Hadron Collider are discussed.
We present unified approach for analyzing experiments on electroluminescence (EL) quantum efficiency (QE) with organic light-emitting diodes (OLEDs). A crucial aspect of the approach is that it ...yields a general formula that describes the ELQE(
j) based on the interplay between the current (
j) – dependent electron-hole recombination rate and EL quenching processes such as excitonic interactions and electric field-assisted dissociation of excited states occurring simultaneously within LEDs’ emitters. Experimental data on Pt
L
26Cl phosphor – based highly efficient OLEDs, are satisfactorily reproduced with this unified approach including the phosphor concentration dependent ratio in the population of monomolecular exciton- and bi-molecular excimer-emitting species.
We investigated a vertical organic field effect transistor (VOFET) behavior with an intermediate electrode formed by a tin (Sn) layer, whose growth presents a self-organized pattern grid with natural ...pores, fundamental to its operation. The choose of the materials to compose the channel formed by a fullerene (
C
60
) and a intermediate electrode of Sn brings a structure able to work with very low voltage and ambipolar gate biasing behavior, concomitantly. A explanation based on the importance of the roughness/pores in the intermediate electrode and the control of the energy barrier of the injection interface clarifies how to obtain the on–off state in unipolar VOFETs with ambipolar gate biasing. A theoretical basis support that when there is a low injection energy barrier inside and outside of the pores from a roughness intermediate electrode the electrical characterization its a combination of a very low voltage operation with a non negligible off-output current.
From the LHC to future colliders De Roeck, A; Ellis, J; Grojean, C ...
The European physical journal. C, Particles and fields,
04/2010, Letnik:
66, Številka:
3-4
Journal Article
Recenzirano
Odprti dostop
Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and ...prospects of LHC running with 10 to 300 fb−1 of integrated luminosity, of the proposed sLHC luminosity upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10 fb−1 of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because the Higgs properties are such that it is difficult to detect or because no Higgs boson exists, (iii) a missing-energy signal beyond the Standard Model is discovered as in some supersymmetric models, and (iv) some other exotic signature of new physics is discovered. In the contexts of these scenarios, the Working Groups reviewed the capabilities of the future colliders to study in more detail whatever new physics may be discovered by the LHC. Their reports provide the particle physics community with some tools for reviewing the scientific priorities for future colliders after the LHC produces its first harvest of new physics from multi-TeV collisions.
Numerous non-standard dynamics are described by contact-like effective interactions that can manifest themselves in electronapositron collisions only through deviations of the observables (cross ...sections, asymmetries) from the Standard Model predictions. If such a deviation were observed, it would be important to identify the actual source among the possible non-standard interactions as many different new physics scenarios may lead to very similar experimental signatures. We study the possibility of uniquely identifying the indirect effects of s-channel sneutrino exchange, as predicted by supersymmetric theories with R-parity violation, against other new physics scenarios in high-energy e + e - annihilation into lepton pairs at the International Linear Collider. These competitive models are interactions based on gravity in large and in TeV-scale extra dimensions, anomalous gauge couplings, Z a2 vector bosons and compositeness-inspired four-fermion contact interactions. To evaluate the identification reach on sneutrino exchange, we use as basic observable a double polarization asymmetry, that is particularly suitable to directly test for such s-channel sneutrino exchange effects in the data analysis. The availability of both beams being polarized plays a crucial role in identifying the new physics scenario.
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