Search results for "Coupling"
showing 10 items of 1862 documents
Higher-order effects for the coupling constant in asymptotically free theories
1977
It is shown that the two-loop contribution to the Callan-Symanzik $\ensuremath{\beta}$ function leads to an effective coupling constant which may be quite different from the value obtained from the standard one-loop calculation. This correction is larger than that due to finite quark masses. Possible implications for the comparison between asymptotically free theories and experiment are discussed.
Tevatron Combination of Single-Top-Quark Cross Sections and Determination of the Magnitude of the Cabibbo-Kobayashi-Maskawa Matrix Element Vtb
2015
et al.
Single and Double Beta-DecayQValues among the TripletZr96,Nb96, andMo96
2016
The atomic mass relations among the mass triplet ^{96}Zr, ^{96}Nb, and ^{96}Mo have been determined by means of high-precision mass measurements using the JYFLTRAP mass spectrometer at the IGISOL facility of the University of Jyvaskyla. We report Q values for the ^{96}Zr single and double β decays to ^{96}Nb and ^{96}Mo, as well as the Q value for the ^{96}Nb single β decay to ^{96}Mo, which are Q_{β}(^{96}Zr)=163.96(13), Q_{ββ}(^{96}Zr)=3356.097(86), and Q_{β}(^{96}Nb)=3192.05(16) keV. Of special importance is the ^{96}Zr single β-decay Q value, which has never been determined directly. The single β decay, whose main branch is fourfold unique forbidden, is an alternative decay path to the…
Co-Evolutionary Coupling via a Digital-bio Ecosystem : A Suggestion for a New R&D Model in the Digital Economy
2019
A solution to the critical problem of a dilemma between R&D expansion and productivity decline that a majority of information and communication technology (ICT) leaders have been confronting in the digital economy is expected. It can be expected by a spinoff from economic functionality-seeking GDP-based coevolution cycle to supra-functionality beyond an economic value-seeking uncaptured GDP-driven coevolution cycle. However, the transformation dynamism remains a black box. By means of numerical simulations based on empirical analyses of the development trajectories of global ICT leaders, focusing on Amazon and Finland, together with an intensive review of preceding analyses, this paper atte…
Electronic coupling responsible for energy transfer in columnar liquid crystals
1999
Electronic coupling is the driving force for energy transfer in molecular materials and consists of several components. We determine the strength of dipolarrmultipolar coupling and coupling due to orbital overlap for excitation transport in triphenylene columnar liquid crystals. We use time-resolved fluorescence spectroscopy and computer simulations. The fit of the experimental and simulated fluorescence decays reveals that the transfer process is dominated by short range interactions .multipolar and orbital overlap but the contribution of long range dipolar interactions cannot be neglected. q 1999 Elsevier Science B.V. All rights reserved.
Electron-phonon heat transport in degenerate Si at low temperatures
2004
The thermal conductance between electrons and phonons in a solid state system becomes comparatively weak at sub‐Kelvin temperatures. In this work five batches of thin heavily doped silicon‐on‐insulator samples with the electron concentration in the range of 2.0–16 × 1019 cm–3 were studied. Below 1 K all the samples were in the dirty limit of the thermal electron‐phonon coupling, where the thermal phonon wavelength exceeds the electron mean free path. The heat flow between electrons and phonons is proportional to (T6e–T6ph), where Te (Tph) is the electron (phonon) temperature. The constant of proportionality of the heat flow strongly depends on the electron concentration and its magnitude is…
EPR Studies of Atomic Impurities in Rare Gas Matrices
2003
In this article we give an overview of the matrix isolation technique combined with electron paramagnetic resonance (EPR) detection for embedded atomic impurities in solid rare gases. A special emphasis is put on impurity – matrix coupling effects combining both experimental and theoretical approaches.
Design of Radiation-Hardened Rare-Earth Doped Amplifiers through a Coupled Experiment/Simulation Approach
2013
International audience; We present an approach coupling a limited experimental number of tests with numerical simulations regarding the design of radiation-hardened (RH) rare earth (RE)-doped fiber amplifiers. Radiation tests are done on RE-doped fiber samples in order to measure and assess the values of the principal input parameters requested by the simulation tool based on particle swarm optimization (PSO) approach. The proposed simulation procedure is validated by comparing the calculation results with the measured degradations of two amplifiers made with standard and RH RE-doped optical fibers, respectively. After validation, the numerical code is used to theoretically investigate the …
Carbocatalytic Oxidative Dehydrogenative Couplings of (Hetero)Aryls by Oxidized Multi‐Walled Carbon Nanotubes in Liquid Phase
2019
HNO3-oxidized carbon nanotubes catalyze oxidative dehydrogenative (ODH) carbon-carbon bond formation between electron-rich (hetero)aryls with O-2 as a terminal oxidant. The recyclable carbocatalytic method provides a convenient and an operationally easy synthetic protocol for accessing various benzofused homodimers, biaryls, triphenylenes, and related benzofused heteroaryls that are highly useful frameworks for material chemistry applications. Carbonyls/quinones are the catalytically active site of the carbocatalyst as indicated by model compounds and titration experiments. Further investigations of the reaction mechanism with a combination of experimental and DFT methods support the compet…
ChemInform Abstract: Oxidative Transformation of Aryls Using Molybdenum Pentachloride
2012
Molybdenum pentachloride combines a strong Lewis acid character with an unusually high oxidation potential creating a powerful reagent for oxidative transformations. Since the oxidative coupling reaction of aryls is induced at an extraordinarily high reaction rate, a variety of labile groups, e.g. iodo, tert-alkyl, etc., are tolerated on the aromatic core. Furthermore, the co-formed molybdenum salts can either be exploited for template effects to obtain uncommon geometries in a preferred manner, or redox-play starts after aqueous workup. Therefore MoCl5 represents a unique and easily available reagent.