共查询到20条相似文献,搜索用时 15 毫秒
1.
K. I. Arshinov A. S. Dudarenok N. N. Lavrentieva V. V. Nevdakh 《Journal of Applied Spectroscopy》2011,78(5):646-649
Relative coefficients of collisional broadening caused by N2O molecules and their temperature dependences are determined for absorption lines (1000–0001 transition, R-branch) of the CO2 molecule. 相似文献
2.
K. I. Arshinov O. N. Krapivnaya V. V. Nevdakh V. N. Shut 《Journal of Applied Spectroscopy》2017,84(5):739-743
3.
Kiichirou?Koyasu Wilko?Westh?user Marco?Niemietz Jan?Heinen Gerd?Gantef?r 《Applied Physics A: Materials Science & Processing》2009,96(3):679-684
Using time-resolved photoelectron spectroscopy, the decay channels of AuO2− and Au2O2− following photoexcitation with 3.1-eV photons have been studied. For AuO2−, a state with a rather long lifetime of 30 ps has been identified. Its decay path could not be determined but photodesorption
can be excluded. For Au2O2−, the spectra indicate O2 desorption after 3.1-eV photoexcitation on a time scale of 1 ps. While comparing these results on Au
n
O2− with analogous data on Ag
n
O2− clusters, a discernible pattern emerges: for dissociatively bound O2(AuO2−, Ag3O2−), there are long-living excited states which do not decay by oxygen desorption, while for molecular chemisorption (Au2O2−, Ag2O2−, Ag4O2−, Ag8O2−), the 3.1-eV photoexcitation triggers fast O2 desorption with a high quantum yield. 相似文献
4.
Lukáš Pichl 《Czechoslovak Journal of Physics》2005,55(2):167-171
An accurate calculation of the lowest negative electronic state of H
2
-
(fixed nuclei) is reported using the CCSD(T) method and doubly augmented cc-pv5z basis set. Comparison has been made with the reference data by Senekowitsch et al. [Chem. Phys. Lett. 111 (1984) 211]. Owing to larger size of the basisset and inclusion of triple excitations, no vertical shift in this work is necessary to reproduce the asymptotics of H + H -. In addition, the effect of basis-set truncation is estimated, based on the complete-basis-set extrapolation method. The contribution of correlated electron-proton motion to the electron-energy curve for H2
– dynamics is pointed out.Dedicated to Prof. Jií Horáek on the occasion of his 60th birthday. 相似文献
5.
N. E. Sluchanko A. N. Azarevich A. V. Bogach S. Yu. Gavrilkin V. V. Glushkov S. V. Demishev A. V. Dukhnenko A. B. Lyashchenko K. V. Mitsen V. B. Filipov 《JETP Letters》2011,94(8):642-646
The specific heat of the ZrB12 compound in the normal and superconducting states (T
C
≈ 6 K) has been studied in the 1.9–7 K temperature range for high-quality single crystals with different relative contents
of boron isotopes. For Zr10B12, ZrnatB12, and Zr11B12 dodecaborides, the electron density of states and the electronphonon coupling constant, λe-ph ∼ 0.4, are found. The dependence of the thermodynamic and upper critical fields, as well as of the Ginzburg-Landau parameter
(κ = 0.8–1.14) on temperature and isotope composition is determined. The results suggest the existence of the magnetic field
induced phase transition at T* = 4–5 K, which is not related to the transition from type-I to type-II superconductivity. The possibilities of the existence
of two-gap superconductivity and a structural phase transition at T* in zirconium dodecaboride are discussed. 相似文献
6.
We perform a theoretical study based on dispersion relations of the reaction γγ → π
0
π
0 emphasizing the low-energy region. We discuss how the ƒ
0(980) signal emerges in γγ → ππ within the dispersive approach and how this fixes to a large extent the phase of the isoscalar S-wave γγ → ππ amplitude above the threshold. This allows us to make sharper predictions for the cross-section at lower energies and our results could then
be used to distinguish between different ππ isoscalar S-wave parameterizations with the advent of new precise data on ππ → π
0
π
0. We compare our dispersive approach with an updated calculation employing the unitary chiral perturbation theory (U
gC
PT). We also pay special attention to the role played by the σ-resonance in γγ → ππ and calculate its coupling and width to γγ, for which we obtain Γ(σ → γγ) = (1.68 ± 0.15) keV. 相似文献
7.
We use experimental data on e + e ? → (η′)π+π? and conservation of vector current to estimate the branching fractions of τ? decay to η(η′)π?π0ντ. The obtained values are compared to the experimental results. 相似文献
8.
V. I. Murav’ev 《Physics of the Solid State》2004,46(5):853-857
The parameters of hyperfine interactions in Pb3+F 8 ? F a ? tetragonal clusters of MeF2 crystals (Me=Ca, Sr, Ba) are interpreted. The contributions of the spin polarization to the parameters of the proper hyperfine interaction and additional (ligand) hyperfine interactions are calculated in the approximation of weak binding between a charge-compensating ion F a ? and a cubic fragment in the tetragonal cluster. It is demonstrated that correct inclusion of the contributions from the spin polarization to the ligand isotropic hyperfine interaction for the F a ? ion leads to anomalously large parameters of this interaction for MeF2 crystals. These results are in agreement with experimental data. 相似文献
9.
Red-light-emitting Y2O3:Eu3+ thin-film phosphors were synthesized using a sol–gel process. The effect of Mg2+ and Al3+ co-dopants on the Y2O3:Eu3+ thin-film phosphor photoluminescence (PL) property was investigated. At a certain concentration, both Mg2+ and Al3+ co-dopants were found to further enhance the PL emission intensity of Y2O3:Eu3+ thin-film phosphors. The optimum PL emission intensity was observed in Y2O3:12%Eu3+, 7%Mg2+ and Y2O3:12%Eu3+, 2%Al3+ phosphor films. From our results, the enhancement of the emission intensity by the Mg2+ and Al3+ co-dopants is explained in terms of the creation of defect states near the Y(4d+5s) conduction band, which overlap with the Eu3+ charge-transfer state (CTS). The overlapping leads to CTS broadening and consequently induces higher absorption and hence an increase of the emission intensity. From X-ray diffraction results, we have found that there is no additional phase formed in the co-doped phosphor films. PACS 68.55.Ln; 78.55.-m; 81.20.Fw 相似文献
10.
Halogen-substituted barium indate Ba2In2O5 based brownmillerites Ba1.95In2O4.9F0.1 and Ba1.95In2O4.9Cl0.1 have been synthesized. It has been verified radiographically that the single-phase condition is satisfied. The effect of the substituent ion nature on parameters of the crystalline lattice and lengths of In–O bonds has been revealed. The propensity of the phases under study for hydration and formation of energetically unequal ОН– groups in the structure has been proved. In both the cases of doping, the degree of hydration decreased as compared to barium indate Ba2In2O5, which is caused by the participation of the halide ion in the tetrahedral site of indium. 相似文献
11.
I. A. Semerikov I. V. Zalivako A. S. Borisenko K. Y. Khabarova N. N. Kolachevsky 《Journal of Russian Laser Research》2018,39(6):568-574
We propose a method for EIT ground state cooling of 171Yb+ ion, which involves three light fields with detuning on a MHz scale. The steady-state mean vibrational quantum number is calculated to be less than 0.005. Efficient cooling is achievable in a motional-mode frequency range of 2π · (1.5 ± 0.5 MHz). 相似文献
12.
The results of earlier calculations of τ → (π0, η, η′, K0)K–ντ processes in the extended Nambu–Jona-Lasinio model are compared. The full widths of these processes are given. The contributions of intermediate vector and scalar mesons both in the ground state and in the first radially excited one (K*(892), K*(1410), K0*(800), K0*(1430), ρ(770), and ρ(1450)) are taken into account. The results are in reasonable agreement with the experimental data. 相似文献
13.
Zhi-Gang Wang Shao-Long Wan 《The European Physical Journal C - Particles and Fields》2007,50(4):781-791
In this article, we calculate the vector form factors f+
Kπ(Q2) and f-
Kπ(Q2) within the framework of the light-cone QCD sum rule approach. The numerical values of f+
Kπ(Q2) are compatible with existing theoretical calculations, and the central value of f+
Kπ(0) (f+
Kπ(0)=0.97) is in excellent agreement with the values from chiral perturbation theory and lattice QCD. The values of |f-
Kπ(0)| are very large compared to the theoretical calculations and experimental data, and they cannot give any reliable prediction.
At large momentum transfer with Q2 > 5 GeV2, the form factors f+
Kπ(Q2) and |f-
Kπ(Q2)| can either show the asymptotic behavior of or decrease more quickly than ; more experimental data are needed to select the ideal sum rules.
PACS 12.38.Lg; 12.38.Bx; 12.15.Hh 相似文献
14.
A. Mokhles Gerami K. Johnston H. P. Gunnlaugsson K. Nomura R. Mantovan H. Masenda Y. A. Matveyev T. E. Mølholt M. Ncube S. Shayestehaminzadeh I. Unzueta H. P. Gislason P. B. Krastev G. Langouche D. Naidoo S. Ólafsson the ISOLDE collaboration 《Hyperfine Interactions》2016,237(1):75
Emission Mössbauer spectroscopy has been utilised to characterize dilute 57Fe impurities in In 2O3 following implantation of 57Mn (T 1/2 = 1.5 min.) at the ISOLDE facility at CERN. From stoichiometry considerations, one would expect Fe to adopt the valence state 3 + , substituting In 3+, however the spectra are dominated by spectral lines due to paramagnetic Fe2+. Using first principle calculations in the framework of density functional theory (DFT), the density of states of dilute Fe and the hyperfine parameters have been determined. The hybridization between the 3d-band of Fe and the 2p band of oxygen induces a spin-polarized hole on the O site close to the Fe site, which is found to be the cause of the Fe2+ state in In 2O3. Comparison of experimental data to calculated hyperfine parameters suggests that Fe predominantly enters the 8b site rather than the 24d site of the cation site in the Bixbyite structure of In 2O3. A gradual transition from an amorphous to a crystalline state is observed with increasing implantation/annealing temperature. 相似文献
15.
We are herewith reporting the 151Eu Mössbauer spectra collected on a polycrystalline powder sample of Eu0.75Y0.25MnO3 from 15 K to room temperature. All the spectra consist of a single line, whose shape and related sample thickness are dependent on the temperature T. The thermal trend of the mean square displacement of Eu ion, obtained from the spectra analysis, clearly reveals a large low-temperature anharmonicity and in concomitance with the onset of the magnetic ordering consists in a linear strong decrease interrupted by two narrow wells at 29.5 K and 40 K. This behavior is interpreted in connection with the transfer of spectral weight from the 120 cm-1 optical phonon to the electromagnonic modes. The T-trend of the central shift shows that Eu3+ electronic ground state in the magnetically ordered phase differs from the one in the paramagnetic state. Finally, the temperature dependence of the hyperfine field under T N gives a contribution to interpret some controversial features regarding the phase-diagram. 相似文献
16.
The near-threshold 12C(02+) resonance provides unique possibility for fast helium burning in stars, as predicted by Hoyle to explain the observed abundance
of elements in the Universe. Properties of this resonance are calculated within the framework of the α cluster model whose
two-body and three-body effective potentials are tuned to describe the α-α scattering data, the energies of the 01+ and 02+ states, and the 01+-state rootmean-square radius. The extremely small width of the 02+ state, the 02+ → 01+ monopole transition matrix element, and transition radius are found in remarkable agreement with the experimental data. The
02+-state structure is described as a system of three α particles oscillating between the ground-state-like configuration and
the elongated chain configuration whose probability exceeds 0.9. 相似文献
17.
18.
V. P. Tarasov G. A. Kirakosyan 《Russian Journal of Physical Chemistry B, Focus on Physics》2016,10(4):582-586
The effect of the 16O ? 18O substitution in the coordination sphere of permanganate anion MnO 4 ? on the chemical shift of 55Mn nuclei have been studied by 17O and 55Mn NMR. Time constants τ n,k of oxygen exchange in the water–permanganate anion system have been estimated. In nearly neutral solutions (pH ≈ 6.8–7.2), the oxygen exchange time is on the order of tens of hours. Bubbling gaseous HCl through this solution for a few seconds leads to the equilibrium distribution of oxygen isotopes in the manganese coordination sphere. The observed temperature dependences of isotope-induced 55Mn NMR shifts in Mn16 O 44-n 18 O n – (n = 0–4) have been treated as a result of rovibrational averaging of Mn–O bond lengths. The change in the Mn—O bond length in caused by the 16O → 18O isotope substitution is on the order of 10–4 Å. 相似文献
19.
A frequency stabilized, tuneable CO2 laser is used to measure the unsaturated absorption coefficients of pure carbon dioxide gas at pressures of 1 and 100 Torr
and temperatures of 296–700 K. The radiative transition probability and the temperature dependence of the collisional self-broadening
coefficient are determined for the R22 absorption line of the 1000-0001 transition of the CO2 molecule. The exponent on the temperature is found to depend on the method used to determine the collisional self-broadening
coefficient. 相似文献
20.
I. D. Petrov V. L. Sukhorukov M. W. Ruf H. Hotop 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,53(3):289-302
Absolute photoionization cross sections for Ne atoms in the excited
levels (Paschen notation
) were calculated at near threshold energies within
the configuration interaction Pauli-Fock approach including core polarization.
The computed spectra and the lineshape parameters of the odd parity
2p1/2
5ns′/d′ autoionizing resonances are
found to be in good agreement with high resolution laser spectroscopic
results. Guided by the theoretical results, improved analyses of the measured
spectra by superimposed Fano-type profiles were achieved. Theoretical
predictions are presented for resonances which have not yet been studied
experimentally. In addition, we report the absolute partial photoionization
cross sections for the 2P3/2 and 2P1/2 channel at
photoelectron energies up to 7 eV. Except for the highest lying 2p1(1S0) level, these cross sections monotonically decrease with
energy (as reported earlier in single-electron calculations for the
Ne(2p53p) configuration) with branching ratios which essentially reflect
the core composition of the 2px levels. For the 2p1 level the resonance structure and the
partial cross sections are strongly influenced by a
Cooper-Seaton minimum in the d3/2
′ channel,located just above the 2P1/2 ionization limit. 相似文献