Search results for "DEPENDENCE"
showing 10 items of 2462 documents
Band-to-Band and Band-to-Acceptor Photoluminescence Studies in InSe under Pressure
1999
We report on photoluminescence (PL) measurements under pressure on p-type N-doped InSe at 10 K and on n-type Si-doped InSe at room temperature. Low-temperature PL of N-doped InSe is dominated by a band-to-acceptor peak. From the pressure dependence of the ionization energy of the N related shallow acceptor, the pressure change of the hole effective mass is estimated through the Gerlach-Pollmann model for hydrogenic levels in uniaxial crystals and discussed in the framework of a k p model. Room temperature PL in Si-doped InSe is dominated by a band-to-band peak exhibiting a pressure shift in agreement with previous works. This PL peak has been measured up to 7 GPa and a steep reversible decr…
�ber die Abh�ngigkeit des Polarisationsgrades vom Streuwinkel bei Mott-Streuung langsamer Elektronen
1965
The angular dependence of polarizationP(Θ) of electrons elastically scattered by a beam of mercury atoms is measured in a double scattering experiment for electron energies of 0,9; 1,2; and 1,5 keV. The results are compared with theory and found to be in good agreement. Maximum degree of polarization measured isP=0,53±0,10 (electron current 10−12A).
The resistivity and thermopower of amorphous Mg-Zn alloys
1983
The resistivity and thermopower of amorphous Mg-Zn alloys have been computed as a function of temperature and composition. The diffraction model incorporating the dynamical partial structure factors is applied. The effect of the electron mean free path is investigated. The authors find that the resistivity is well described by the model, and that the inclusion of the mean free path does not change the results considerably. In the case of thermopower the diffraction model turns out to be inadequate: it gives a composition dependence which is against the experimental evidence. This suggests that there exists another scattering mechanism, which is not accounted for by the diffraction model. Th…
High‐temperature behavior of impurities and dimensionality of the charge transport in unintentionally and tin‐doped indium selenide
1993
A systematic study of the electron transport and shallow impurity distribution in indium selenide above room temperature or after an annealing process is reported by means of far‐infrared‐absorption and Hall‐effect measurements. Evidences are found for the existence of a large concentration of deep levels (1012–1013 cm−2), related to impurities adsorbed to stacking faults in this material. Above room temperature impurities can migrate from those defect zones and then become shallow in the bulk. The subsequent large increase of 3D electrons can change the dimensionality of the electron transport, which in most cases was 2D. The temperature dependence of the resistivity parallel to the c axis…
Transport properties of nitrogen doped p‐gallium selenide single crystals
1996
Nitrogen doped gallium selenide single crystals are studied through Hall effect and photoluminescence measurements in the temperature ranges from 150 to 700 K and from 30 to 45 K, respectively. The doping effect of nitrogen is established and room temperature resistivities as low as 20 Ω cm are measured. The temperature dependence of the hole concentration can be explained through a single acceptor‐single donor model, the acceptor ionization energy being 210 meV, with a very low compensation rate. The high quality of nitrogen doped GaSe single crystals is confirmed by photoluminescence spectra exhibiting only exciton related peaks. Two phonon scattering mechanisms must be considered in orde…
"Table 7" of "Measurement of the production cross section for W-bosons in association with jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS de…
2011
The cross section times branching ratio for W+jets in the electron channel as a function of the next-to-leading jet PT.
"Table 5" of "Measurement of the production cross section for W-bosons in association with jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS de…
2011
The cross section times branching ratio for W+jets in the electron channel as a function of the leading jet PT.
Quantitative prediction of gas-phase F19 nuclear magnetic shielding constants
2008
Benchmark calculations of (19)F nuclear magnetic shielding constants are presented for a set of 28 molecules. Near-quantitative accuracy (ca. 2 ppm deviation from experiment) is achieved if (1) electron correlation is adequately treated by employing the coupled-cluster singles and doubles (CCSD) model augmented by a perturbative correction for triple excitations [CCSD(T)], (2) large (uncontracted) basis sets are used, (3) gauge-including atomic orbitals are used to ensure gauge-origin independence, (4) calculations are performed at accurate equilibrium geometries [obtained from CCSD(T)/cc-pVTZ calculations correlating all electrons], and (5) vibrational averaging and temperature corrections…
Political Instability, Transnational Tourist Companies and Destination Recovery in the Middle East after 9/11
2007
The change and mobility of images is one of the main forces influencing contemporary tourism. Tourists decide whether to travel to a destination or not on the basis of changing destination images. This is especially true for tourism destinations in the Middle East and North Africa after 9/11. But how do security related destination images affect the actions of the supply side agents? While the impact of incidents of violent political unrest and the consequent changes in destination images on tourist behaviour has been subject to wide academic research, there is a lack of similar studies concerning the supply side. The interdependencies and interactions of transnational hotel companies, loca…
The Impact of Corporate Board Characteristics on Firm Value: A Literature Survey
2018
This chapter provides a review of theoretical and empirical studies that analyze the effects of board characteristics on firm performance. It serves the purpose of demonstrating different approaches to studying corporate board characteristics as well as the importance of examining these characteristics, namely, board size, board independence, board leadership, gender diversity, board busyness and staggered boards.