共查询到20条相似文献,搜索用时 93 毫秒
1.
S. O. Adamson V. V. Kuverova G. K. Ozerov G. V. Golubkov Sh. Sh. Nabiev M. G. Golubkov 《Russian Journal of Physical Chemistry B, Focus on Physics》2018,12(4):620-631
Ab initio calculations of the adiabatic potential curves and matrix elements of radial nonadiabatic coupling of the N2 molecule for the states related to dissociation limits I–V were performed. The most important spectral characteristics of the adiabatic states agreed well with the available experimental and theoretical data. The diabatic states were constructed. The diabatic quantum defects and radial matrix elements of the configuration interaction of the dissociative and Rydberg configurations whose states converge to the ground state \(X^{2}\Sigma{_g^+}\) and the first electronically excited state A2Πu of the \(\rm{N_2^+}\) ion were calculated. The possibility of using the results for calculating the cross sections and rate constants of dissociative recombination and associative ionization within the framework of the multichannel quantum defect theory was discussed. 相似文献
2.
G. V. Golubkov M. G. Golubkov R. J. Buenker 《Journal of Experimental and Theoretical Physics》2011,112(2):187-192
A theory is developed to describe dissociative recombination of a slow electron with a ground-state molecular ion of oxygen
driven by a strong monochromatic electromagnetic field. Mathematically, the theory is based on the time-independent formalism
of radiative scattering matrix whose poles correspond to dressed intermediate states of the complex. The analysis embraces
both transitions to dissociative states and laserinduced nonadiabatic transitions to intermediate bound states of valence
configurations. Key reaction mechanisms are considered, and a classification is given of all allowed transitions to dissociative
states. Partial and total reaction cross sections are calculated by taking into account the contributions from Rydberg, valence,
and dissociative states of O2**. A detailed discussion of results is presented, and feasibility of laser control of the reaction is demonstrated. 相似文献
3.
By means of a flight-time difference apparatus the two collision induced processes of dissociative vibrational excitations $$H_2^ + (10keV,1s\sigma _g ) + target \to (H_2^ + )*(1s\sigma _g ) \to H^ + + H(1s)$$ and $$H_2^ + (10keV,1s\sigma _g ) + target \to (H_2 )*(unspecified) \to H + H$$ have been determined from an asymmetry in the lab-frame resulting from deflections of the centers-of-mass of the incident projectiles. H++H velocity distributions from vibrational excitations of the electronic ground state of the H 2 + ions will be presented which have been directly measured. Competition of any of the higher lying electronically excited states of the projectiles is estimated to be negligible. In the case of dissociative electron capture combined with simultaneous deflections of the centers-of-mass the electronic states of the intermediate H2 molecules and of the H fragments could not be specified. 相似文献
4.
Employing48Ca as the core, the structure of51V is studied in the framework of a conventional shell-model. A pairing-plus-surface-tensor-interaction is used as the effective
two-body interaction. Besides all configurations arising from 1f
7/2 and 2p
3/2 single-particle orbits, configurations of the form
wheren
1+n
2=3 (the number of extracore protons) andn
2 = 1, 2 are also considered. Low-lying energy levels are calculated and a satisfactory agreement with the experimental values
is obtained. Our calculated density of states is higher than that reported previously. We also present theB(E2) values for transitions between low-lying levels and the spectroscopic factors for the50Ti (3He, d)51V reaction. The dependence of the interaction parameters on the mass number of the core nucleus is also studied. 相似文献
5.
R. Riahi Ph. Teulet Z. Ben Lakhdar A. Gleizes 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,56(1):61-66
The weighted total cross section (WTCS) theory has been applied to the
electron-H2 collision to obtain excitation, ionisation and dissociation
cross section and rate coefficients of the X 1Sg+^{1}\!\Sigma _{g}^{+}, c
3Pu^{3}\!\Pi _{u}, a 3Sg+^{3}\!\Sigma _{g}^{+}, e $^{3}\!\Sigma
_{u}^{+}$^{3}\!\Sigma
_{u}^{+} and B′
1Su+^{1}\!\Sigma _{u}^{+} states. Calculation has
been performed in the temperature range 1500 K–15000 K. Rate coefficients
are calculated from WTCS assuming Maxwellian energy distribution functions
for electrons and heavy particles. Thermal equilibrium results are presented
and fitting parameters (a, b and c) are given for each reaction rate
coefficient: k(θ) = a (θb)
exp(-c/θ). 相似文献
6.
J. Lozeille A. Fioretti C. Gabbanini Y. Huang H. K. Pechkis D. Wang P. L. Gould E. E. Eyler W. C. Stwalley M. Aymar O. Dulieu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,39(2):261-269
We present detailed experimental spectra and accurate theoretical interpretation of resonance-enhanced
two-photon ionization of ultracold rubidium molecules in the
14000–17000 cm-1 transition energy range. The dimers are formed in a
magneto-optical trap by photoassociation followed by radiative decay into the a 3Σu+
lowest triplet state. The theoretical treatment of the process, which reproduces the main features
of the spectra, takes into account the photoassociation and decay steps as well as the resonant ionization through the manifold
of intermediate gerade states correlated to the 5S + 4D limit. In particular, the energy of the v=1 level of the
potential well has been determined for the first time. In addition, a tight constraint has been put on the position of the
a 3Σu+
repulsive wall. Finally, magnetic trapping of
rubidium molecules in the a 3Σu+ state is demonstrated.
Electronic supplementary material Online Material 相似文献
7.
H. Rauch 《The European physical journal. Special topics》2008,159(1):27-36
Measurements of the π0 and direct photon nuclear modification
factors in p+p and A+A collisions in the PHENIX experiment
at RHIC will be reviewed and
recent results at
GeV will be presented. Using
for the first time the p+p reference measured in the same
experiment instead of averaging world data the π0 suppression
turns out to be almost as large at
GeV as at
GeV, implying gluon densities dNg/dy>800.
Possible origins of photon suppression at high pT in
GeV are discussed in light of the new results on
photon RAA at
GeV. 相似文献
8.
A new solid substrate-room temperature phosphorescence (SS-RTP) method for the determination of trace manganese (II) has been
established. It bases on the fact that fullerol (R) emits strong and stable room temperature phosphorescence (RTP) on filter
paper substrate. H2O2 can oxidize R to cause the SS-RTP quenching. But manganese (II) can obstruct H2O2 to oxidize R, and enhance the RTP of R. α,α′-Bipyridine (Bipy) can sensitize the RTP. After adding Bipy, the ΔI
p enhances 7 times than that without Bipy. Under the optimum conditions, the linear dynamic range of this method is 0.016–1.12 pg spot−1 with a detection limit (L.D.) of 4.6 fg spot−1 ( is the absolute mass of Mn2+), and the regression equation of working curve is ΔI
p=25.20 + 63.55 (pg spot−1), n=6, r=0.9983. For 0.016 and 1.12 pg spot−1 Mn2+, RSDS are 4.3 and 4.8%, respectively (n=7). This method has been applied to the determination of trace manganese (II) in actual sample with high sensitivity and
good selection. And the reaction mechanism of SS-RTP is discussed. 相似文献
9.
The nuclear spectroscopic quadrupole moments for the πh9/25/2-, 1/2-[541] and the πh11/29/2-, 9/2-[514] isomeric states in 169Ta have been measured employing the time differential perturbed angular-distribution technique following the nuclear reaction
159Tb(16O, 6nγ)169Ta at beam energy 104 MeV. The ratio of the intrinsic quadrupole moments
has been derived as 1.87(13) from the measured quadrupole precession frequencies of the corresponding states. The model-independent
analysis of the equilibrium deformation indicates strong prolate- and oblate-driving nature of the 1/2-[541] and 9/2-[514] orbitals in 169,171Ta isotopes, respectively. 相似文献
10.
A recurrence procedure for a sequential construction of kernels \(G_{{l_1},{l_2}}^l\) (c, c1, c2) appearing upon the expansion of a nonlinear collision integral of the Boltzmann equation in spherical harmonics is developed. The starting kernel for this procedure is kernel G0,00 (c, c1, c2) of the collision integral for the distribution function isotropic with respect to the velocities. Using the recurrence procedure, a set of kernels \(G_{{l_1},{l_2}}^{ + l}\) (c, c1, c2) for a gas consisting of hard spheres and Maxwellian molecules is constructed. It is shown that the resultant kernels exhibit similarity and symmetry properties and satisfy the relations following from the conservation laws. 相似文献
11.
J. Lecointre D. S. Belic S. Cherkani-Hassani P. Defrance 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,63(3):441-448
Absolute cross sections for electron impact dissociation of ND+ leading to the formation of D+ have been measured by applying the animated electron-ion beam method in the energy range from the reaction threshold up to
2.5 keV. The maximum inclusive cross section is observed to be (16.8 ± 0.8) × 10−17 cm2 at the electron energy of 65.1 eV. The appearance energy for the D+ production is measured to be (4.0 ± 0.5) eV. Collected data are analyzed in details by means of an original procedure in
order to determine separately the contributions of dissociative channels. A specific Monte Carlo modeling has been developed,
which is proven to reconstruct adequately the dissociative ionization cross section. The present energy thresholds provide
information about the ground and excited states of the molecular ion, as well as about the possible population of the vibrational
levels. The reaction D2(v) + N+ (or H2(v) + N+) is a probable source for that population and it constitutes the first step of the molecular activated processes, so the
corresponding chain of reactions has to be considered to study the chemistry of plasma sources. 相似文献
12.
D P Ahalpara 《Pramana》1978,10(4):399-408
Collective bands of the positive parity states in odd-A f
7/2 shell nuclei are described in the framework of deformed Hartree-Fock theory by projecting states from lowest energy intrinsic
states with (d
3
2/−1
f
7
2/n+1
) one hole configurations. In the calculation empirical (d
3/2 −f
7/2)2 effective matrix elements have been used to test the tacit assumptions of the Bansal and French model. 相似文献
13.
F. Song L. Han C. Zou J. Su K. Zhang L. Yan J. Tian 《Applied physics. B, Lasers and optics》2007,86(4):653-660
Upconversion blue emissions of Tm3+-ion-heavy-doped NaY(WO4)2 crystals are investigated with three different near-infrared pump mechanisms. The dependence of upconversion efficiency on
the pump mechanism is analyzed from the scope of the concentration quenching effect. Three cross-relaxation processes, , , and , which influence the upconversion dominantly in the Tm3+-heavy-doped system, are demonstrated theoretically and experimentally. The results indicate that Yb3+ ions can weaken the concentration quenching effect of Tm3+ ions significantly so that the blue emission efficiency can be enhanced by one order of magnitude. At the same time, the
wavelength of the pump source also has considerable influence on both the population of some crucial energy levels and the
upconversion mechanism. Experiments show that the upconversion blue emission in Tm3+/Yb3+ co-doped NaY(WO4)2 crystal under 980-nm laser diode excitation is the most intensive of these three different near-infrared pump mechanisms.
The conclusions are confirmed by spectra measurements and calculations of Judd–Ofelt theory and Miyakawa–Dexter theory.
PACS 42.70.Hj; 78.55.-m 相似文献
14.
J. Lecointre H. Cherkani-Hassani S. Cherkani-Hassani D. S. Belic J. J. Jureta P. Defrance 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,60(2):331-345
Absolute cross sections for electron-impact single ionization, dissociative
excitation and dissociative ionization of the ethynyl radical ion
(C2D+)^+) have been measured for electron energies ranging from the
corresponding reaction thresholds to 2.5 keV. The animated crossed
electron-ion beam experiment is used and results have been obtained for the
production of C2D2+, C2+, C2+_2^+ , CD+, C+ and
D+. The maximum of the cross section for single ionization is found to
be (2.01 ± 0.02) × 10-17 cm2, at the incident electron
energy of 105 eV. Absolute total cross sections for the various singly
charged fragments production are observed to decrease by a factor of almost
three, from the largest cross-section measured for C+, over C2+_2^+
and CD+ down to that of D+. The maxima of the cross sections are
obtained to be (14.5 ± 0.5) × 10-17 cm2 for C2+_2^+,
(12.1 ± 0.1) × 10-17 cm2 for CD+, (27.7 ±
0.2) × 10-17 cm2 for C+ and (11.1 ± 0.8) × 10-17 cm2 for D+.
The smallest cross section is measured to
be (1.50 ± 0.04) × 10-18 cm2 for the production of the
doubly charged ion C2+. Individual contributions for dissociative
excitation and dissociative ionization are determined for each
singly-charged product. The cross sections are presented in closed analytic
forms convenient for implementation in plasma simulation codes. Kinetic
energy release distributions of dissociation fragments are seen to extend
from 0 to 6 eV for the heaviest fragment C2+_2^+, up to 11.0 eV for
CD+, 14.2 eV for C+ and 11.2 eV for D+ products. 相似文献
15.
C. Wheldon Tz. Kokalova W. von Oertzen S. Thummerer H. G. Bohlen B. Gebauer A. Tumino T. N. Massey G. de Angelis M. Axiotis A. Gadea Th. Kröll N. Mărginean D. R. Napoli M. De Poli C. Ur D. Bazzacco S. M. Lenzi C. Rossi Alvarez S. Lunardi R. Menegazzo P. G. Bizzeti A. M. Bizzeti-Sona 《The European Physical Journal A - Hadrons and Nuclei》2005,26(3):321-326
Cluster states up to 12 MeV in the stable light nucleus 21Ne, based on the 16O + n + α molecular configurations, have been populated in the incomplete-fusion reaction 16 8O(73Li, np)2110Ne at 29.4 MeV. The observation of both intra- and inter-band transitions leads to a re-interpretation of some levels in the
Kπ =
- and Kπ =
- bands. The implications of this re-ordering on the octupole doublet bands are examined. The data allow a more accurate determination
of some previously uncertain level energies. The “missing” Iπ =
- level is also discussed. 相似文献
16.
J. Moc 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,61(2):397-402
We have studied the interaction of Al13-_{13}^{-} anion
cluster with H2. Both the long range interaction and dissociative
adsorption have been examined using the established correlated ab initio
methods, MP2 and CCSD(T), in conjunction with the augmented correlation
consistent basis sets up to aug-cc-pVTZ. The formation of the weakly bound
(physisorbed) end-on anion complex Al13-_{13}^{-}...H2 is
predicted for the interacting Al...H distances of 3.95 ? with the
H-H axis pointing towards the ‘hollow’ site of Al13-_{13}^{-} and binding
energy (De)D_{e}) of 0.7 kcal/mol at the estimated complete basis set (CBS)
limit of CCSD(T). The barrier height for H2 dissociation on
Al13-_{13}^{-} of 41.6 (42.9) kcal/mol calculated at the ZPVE-corrected
CCSD(T)/aug-cc-pVTZ (estimated CCSD(T)/CBS) level is at least twice as large
as that evaluated by us for a dissociative adsorption of H2 on an
open-shell Al13 neutral cluster. To our knowledge, this report presents
the first “benchmark” quality study of the physisorption and dissociative
chemisorption of molecular hydrogen on Al13-_{13}^{-} anion cluster. 相似文献
17.
D. Elsner A. Süle P. Barneo P. Bartsch D. Baumann J. Bermuth R. Böhm D. Bosnar M. Ding M. Distler D. Drechsel I. Ewald J. Friedrich J. M. Friedrich S. Grözinger P. Jennewein S. Kamalov F. H. Klein M. Kohl K. W. Krygier H. Merkel P. Merle U. Müller R. Neuhausen Th. Pospischil M. Potokar G. Rosner H. Schmieden M. Seimetz O. Strähle L. Tiator Th. Walcher M. Weis 《The European Physical Journal A - Hadrons and Nuclei》2006,27(1):91-97
The reaction p(e, e'p)π0 has been studied at Q2 = 0.2 (GeV/c)2 in the region of W = 1232MeV. From measurements left and right of
, cross-section asymmetries ρLT have been obtained in forward kinematics ρLT(
= 20°) = (- 11.68±2.36stat±2.36sys) and backward kinematics ρLT(
= 160°) = (12.18±0.27stat±0.82sys) π0. Multipole ratios
{S1+ * M1+}/| M1+|2 and
{S0+ * M1+}/| M1+|2 were determined in the framework of the MAID2003 model. The results are in agreement with older data. The unusally strong
negative
{S0+ * M1+}/| M1+|2 required to bring also the result of Kalleicher et al. in accordance with the rest of the data is almost excluded. 相似文献
18.
N. S. Malyshev V. V. Kuverova G. K. Ozerov G. V. Golubkov M. G. Golubkov S. O. Adamson 《Russian Journal of Physical Chemistry B, Focus on Physics》2017,11(1):77-82
A method taking into account valence (non-Rydberg) and dissociative configurations has been developed for calculation of potential energy surfaces of the NO molecule in an intense IR radiation field. The resonance rovibronic structure of the Rydberg molecule–laser field quantum system has been analyzed within the steady-state formalism of the radiation collision matrix using multi-channel quantum defect theory. Special conditions for field control of predissociation involving intermediate Rydberg and valence states have been formulated. 相似文献
19.
We derive, in model-independent way, the spin structure of the matrix element for the reaction of associative Θ+-pentaquark production, π
± + d → Θ+ + Σ±, in the threshold region and in collinear kinematics. The expressions for the polarization observables in this reaction are
found assuming spin 1/2 and different parities for Θ+. We have proved that such a reaction can be used for a model-independent determination of the P parity of Θ+ only by measuring the Θ+ polarization. Other polarization observables, such as the dependence of the Σ± polarization on the vector and tensor deuteron polarizations, are insensitive to the Θ+ parity under the considered kinematical conditions. The linear and quadratic relations between polarization observables in
(Θ+ is unpolarized) do not depend on the parity of the Θ+ pentaquark. The analysis performed for this reaction is also applicable without any modification to the reaction K
+ + d → Θ+ + p. Using the pole model for the reaction mechanism, we estimated the value of the cross section for the reaction K
+ + d → Θ+ + p near the threshold.
The text was submitted by the authors in English. 相似文献
20.
Yu. M. Andreev S. I. Bityukov N. V. Krasnikov A. N. Toropin 《Physics of Atomic Nuclei》2007,70(10):1717-1724
The LHC (CMS) discovery potential in the search for supersymmetry and lepton-flavor violation in neutralino decays using the
e
± μ∓ + E
T
miss
signature is studied. A detailed study is done for the CMS test points LM1-LM9. It is shown that, for the point LM1, it is
possible to detect lepton-flavor violation in neutralino decays with lepton-flavor-violating branching Br(
→ μ±
e
∓
) ≥ 0.04 Br(
→ e
+
e
−
, μ+ μ−
) for an integral luminosity of 10 fb−1. The discovery potential in the mSUGRA-SUSY scenario with tan β = 10, sgn(μ) = + in the (m
0, m
1/2) plane using the e
± μ∓ + E
T
miss
signature is determined.
The text was submitted by the authors in English. 相似文献