共查询到20条相似文献,搜索用时 765 毫秒
1.
W. Szajna M. Zachwieja 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,55(3):549-555
The high-resolution emission spectrum of the A1
Π–X1Σ+ transition of AlH was observed in the 18 000–25 000 cm-1 spectral region using a conventional spectroscopic
technique. The AlH molecules were excited in an Al hollow-cathode
lamp filled with a mixture of Ne carried gas and a trace amount of
NH3. The emission from the discharge was observed with a plane
grating spectrograph and recorded by a photomultiplier tube. In
total 163 transition wave numbers belonging to six bands (0-0,1
and 1-0,1,2,3) were precisely measured and rotationally
analysed. In the final fit the present data have been combined
with available high-resolution measurements of the
vibration-rotation bands by White et al. [J. Chem. Phys. 99,
8371 (1993)]. This procedure enabled extracting molecular
constants for the A1
Π and X1
Σ+ states of AlH. A very
slight local perturbation has been discovered in the v=1
vibration level of the A1
Π state at J=5. This was probably
caused by the interaction with the a3Π state. 相似文献
2.
We present a first detailed experimental study of the C(3)1Σ+ state of the NaRb molecule converging
to the Na(3p) + Rb(5s) states of separated atoms. Two different high resolution spectroscopic methods
have been applied: the Fourier transform spectroscopy of laser induced fluorescence and the V-type
optical-optical double resonance polarization labeling spectroscopy. The entire data field for the
C1Σ+ state of Na85Rb and Na87Rb consists of rovibrational levels with v'=0–64
and J'=4–123. The data were incorporated into a direct fit of a single potential energy curve to the level
energies using the Inverted Perturbation Approach method. As the experimental data extend to the
“shelf" region of the potential at large internuclear separations of 8.5 ?, the C state's suitability
for photoassociation yielding cold heteronuclear NaRb is discussed.
Electronic supplementary material Online Material 相似文献
3.
N. F. Allard N. Bonifaci A. Denat 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,61(2):365-372
We have observed emission spectrum in dense plasmas of helium excited
by a corona discharge at 706.69 nm. In continuation of an analysis of
spectra obtained in gaseous helium at 300 K, we report on a study of
the line parameters of the observed spectra. We discuss the major importance of temperature
and perturber density in the broadening, shift and asymmetry measured from calculated profiles within
a unified line shape semi-classical theory. The comparison is done with existing data derived from experimental
spectra
at 300 K. The theoretical work is extended at lower temperatures down to 40 K. 相似文献
4.
X. T. Xu X. Shao C. H. Yu C. Y. Sun W. Huang E. Feng 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,65(3):383-390
The cross sections for rotational, fine-structure and projection-change transitions in
collision of MgH (2Σ+)
molecule with 3He and 4He atoms were computed at cold and ultracold
temperatures using the ab initio potential energy surface. The significant suppression
feature and resonance pattern caused by spin-rotation interaction were found and
discussed. The collisions exhibit a strong isotope effect in the ultracold regime. The
rotational relaxations of the fine-structure excited energy levels tendentiously preserve
the F index. The ratio of the cross sections for elastic and
spin-flipping collision with 3He partner is always greater than seven orders of
magnitude for the energy range 10-6−1cm-1 and suggests the
MgH molecule is a good candidate for 3He buffer gas cooling. 相似文献
5.
S.-W. Xu Y.-X. Xie Z.-K. Li X.-D. Wang B. Guo C.-G. Leng C.-F. Wang Y. Yu 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):347-351
The 1/2+ ground state and a 11/2- isomer of very neutron-deficient isotope 143Dy were produced by irradiation of an enriched target of 106Cd with 40Ca and studied by using a helium-jet fast tape-transport system in combination with proton-γ, X-γ and γ-γ coincidence measurements.
A simple ( EC + β+) decay scheme of 143mDy with a half-life of 3.0(3) s and a tentative ( EC + β+) decay scheme of 143gDy with a half-life of 5.6(10) s are proposed. As a by-product, the 347- and 545-keV γ transitions in 138Sm following the β-delayed proton emission of 139Gd decay and the 323-keV γ transition in 139Eu following the β-delayed proton emission of 140Tb decay could be observed for the first time.
Received: 20 August 2002 / Accepted: 28 October 2002 / Published online: 11 February 2003
RID="a"
ID="a"e-mail: xsw@ns.lzb.ac.cn
Communicated by D. Schwalm 相似文献
6.
Combining the Okubo-Zweig-Iizuka rule in the decay φ→ρπ→π+π?π0 with the ρ→4π decay amplitudes, we calculate the φ→2π+2π?π0 and φ→π+π?3π0 ones. The partial widths of the above φ decays are evaluated, and the excitation curves in e+e? annihilation are obtained, assuming reasonable particular relations among the parameters characterizing the anomalous terms of the HLS Lagrangian. The evaluated branching ratios Bφ→π+π?3π0 ≈ 2 × 10?7 and Bφ→2π+2π?π0 ≈ 7 × 10?7 are such that, with the luminosity L=500 pb?1 attained at DAΦNE φ factory, one may already possess about 1685 events of the decays φ→5π. 相似文献
7.
O. Civitarese J. Suhonen H. Ejiri 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):353-358
We have performed a theoretical analysis of the ground-state-to-ground-state transitions in 100Mo and 116Cd, based on the quasiparticle random-phase approximation and on a straightforward perturbative scheme. The results show that
the single-state dominance found in the realistic calculations of the nuclear matrix elements, which is consistent with data,
can be viewed as a result of the interference between few two-quasiparticle configurations.
Received: 12 August 2002 / Accepted: 23 October 2002 / Published online: 18 February 2003
RID="a"
ID="a"e-mail: civitarese@fisica.unlp.edu.ar
Communicated by V.V. Anisovich 相似文献
8.
Numerical simulation of the effect of intramolecular electrostatic interactions on redistribution of relative intensities in the vibrational structure of (1 ~ 2)1Π–X1Σ+ rotationally resolved transitions of the KRb molecule is performed within the precision nonadiabatic model of coupled vibrational channels. It is established that mutual perturbation of electronically excited states modifies in a nontrivial way a nodal structure of nonadiabatic wavefunction of the (1 ~ 2)1Π complex, which is possible to use for rising efficiency of twostep laser synthesis and stabilization of ultracold ensembles of KRb molecules in the ground electronic state. 相似文献
9.
A. N. Vodin L. P. Korda A. O. Rastrepina G. E. Tuller I. V. Ushakov 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(6):761-765
The excitation function for the 40Ar(pγ)41K reaction at the accelerated proton energy E p= 450–2700 keV is studied. Positions of 168 resonances identified as levels of the 41K nucleus are observed in this energy range. The data for the proton energy E p < 1 MeV and E p > 2 MeV are obtained for the first time. Relative yields of γ rays observed in the decay of the resonances are calculated from a comparison with the yield of the calibrating resonance at E p= 1102 keV. Total radiation widths of the resonances are calculated on the basis of the data obtained. 相似文献
10.
Cross-sections, beam asymmetries, and recoil polarisations for the reactions γp → K
+Λ;γp → K
+Σ0, and γp → K
0Σ+ have been measured by the SAPHIR, CLAS, and LEPS Collaborations with high statistics and good angular coverage for centre-of-mass
energies between 1.6 and 2.3 GeV. The combined analysis of these data with data from π and η photoproduction reveals evidence
for new baryon resonances in this energy region. A new P11 state with mass 1840 MeV and width 140 MeV was observed contributing to most of the fitted reactions. The data demand the
presence of two D13 states at 1875 and, optimistically, at 2170 MeV. 相似文献
11.
Vida Zohrabi-Kalantari Philipp Heidler Marcel Kaiser Reto Brun Christoph Kamper Andreas Link 《Molecular diversity》2010,14(2):307-320
Abstract
A series of 30 adenosine derivatives with three different substituents at the N6-position were prepared in order to evaluate their potential to inhibit the pathogenic protozoa Plasmodium falciparum and Trypanosoma brucei in vitro. The rationale for synthesis of these structures was the high probability of interactions with multiple adenosine associated targets and the assumption that N6-substitutents should increase stability against adenosine deaminases and allow the molecules to diffuse across parasite membranes. Starting from inosine, the new compounds were prepared as single isomers using a polymer-assisted acylation protocol enabling the straightforward isolation of the target compounds in pure form. Three of the compounds displayed anti-plasmodial and one anti-trypanosomal activity in the single digit micromolar concentration range. 相似文献12.
A. A. Rimskii-Korsakov V. V. Koltsov V. V. Karasev 《Bulletin of the Russian Academy of Sciences: Physics》2016,80(8):880-883
The scheme of the β-decay of 234Th is still not completely clear. Only the upper bound (10 keV) of the energy of the isomeric transition from level T1/2 = 1.17 min of the 234Pa nucleus is known, and the correspondence between gamma quanta of several energies emitted in the β-decay of 234Th and specific nuclear levels of 234Pa has not been established. In this work, the isomeric transition energy of 2.6 ± 0.5 keV is determined via the γ-spectrometry of a 234Th source in γγ-coincidences, and a new 234Pa level populated in the β-decay of 234Th is introduced. 相似文献
13.
We discuss the reaction π-e- → π-e-π0 with the purpose of obtaining information on the γπ → ππ anomalous amplitude
3π. We compare a full calculation at
(p6) in chiral perturbation theory and various phenomenological predictions with the existing data of Amendolia et al. By integrating our theory results using Monte Carlo techniques, we obtain σ = 2.05 nb at
(p6) and σ = 2.17 nb after including the dominant electromagnetic correction. Both results are in good agreement with the experimental cross-section of σ = (2.11±0.47) nb. On the basis of the ChPT results one would extract from the experimental cross-section as amplitudes
3π(0)extr = (9.9±1.1) GeV-3 and
3π(0)extr = (9.6±1.1) GeV-3, respectively, which have to be compared with the low-energy theorem
3π = e/(4π2Fπ3) = 9.72GeV-3. We emphasize the need for new data to allow for a comparison of experimental and theoretical distributions and to obtain
3π with smaller uncertainty. 相似文献
14.
Yu. B. Burkatovskaya V. M. Bystritsky G. N. Dudkin A. R. Krylov A. S. Lysakov S. Gazi J. Huran B. A. Nechaev V. N. Padalko A. B. Sadovsky Yu. G. Tuleushev M. Filipowicz A. V. Philippov 《Physics of Particles and Nuclei Letters》2016,13(2):190-197
The cross section of the reaction D(4He, γ)6Li with titanium and zirconium deuterides as targets is measured for incident 4He+ ion energies of 30 and 36 keV, respectively. The ion beam is generated by a Hall pulsed plasma accelerator. For the first time, upper limits on the cross section of the reaction D(4He, γ)6Li at ultralow energies are imposed (at 90% confidence level): σ ≤ 1.2 × 10?35 cm2 for the TiD2 target and E(4He+) = 30 keV, and σ ≤ 7 × 10?36 cm2 for the ZrD2 target and E(4He+) = 36 keV 相似文献
15.
16.
Y. Kojima M. Shibata A. Taniguchi T. Hanafusa E. Yoshida K. Shizuma Y. Kawase S. Yamada 《The European Physical Journal A - Hadrons and Nuclei》2003,16(3):331-336
The β--decay of 151Pr produced by the thermal neutron-induced fission of 235U has been studied using an on-line isotope separator. From an internal-conversion electron measurement with a Si(Li) detector,
K-conversion coefficients were obtained for 20 γ-transitions. Spins and parities of 6 excited levels in 151Nd were newly determined from the deduced multipolarities: even parities for the 543 and 627 keV levels, odd parities for
250 and 599 keV, (3/2, 5/2)+ for 685 keV, and (1/2, 3/2)+ for 880 keV. The level structure was compared with the rotation-vibration coupling Nilsson model.
Received: 28 June 2002 / Accepted: 31 October 2002 / Published online: 25 February 2003
RID="a"
ID="a"e-mail: ykojima@hiroshima-u.ac.jp
Communicated by J. ?yst? 相似文献
17.
The ground-state energies and the squared moduli of the ground-state wave functions are calculated for the 3H, 3,4,6He, 6Li, and 9Be nuclei by Feynman’s continual (path) integrals method. The results are in satisfactory agreement with experimental data. 相似文献
18.
An experiment devoted to studying neutron–neutron angular correlations in the slow-neutroninduced fission of 233U, 235U and 239Pu nuclei was performed. The experimentally determined angular dependence of the number of neutron–neutron coincidences was compared with the results of a Monte Carlo simulation for various values of the neutron-detection threshold in the range between 490 and 2080 keV. It was found that the experimental angular distributions in question can be described well under the assumption that 2% to 5% of all prompt fission neutrons are emitted isotropically in the laboratory frame. Probably, such neutrons can be interpreted as so-called scission neutrons directly associated with the nuclear-rupture instant. Energy distributions of this component were also obtained from the present analysis. 相似文献
19.
L. Gialanella F. Strieder L. Campajola A. D'Onofrio U. Greife G. Gyurky G. Imbriani G. Oliviero A. Ordine V. Roca C. Rolfs M. Romano D. Rogalla C. Sabbarese E. Somorjai F. Terrasi H.P. Trautvetter 《The European Physical Journal A - Hadrons and Nuclei》2000,9(3):303-305
The absolute cross section σ (E) of the radiative capture reaction p(7Be,γ)8B at the center-of-mass energy E = 992 keV has been measured using a radioactive 7Be ion beam and a windowless gas target system filled with H2 gas. The 8B residual nuclides were detected with a recoil separator consisting of momentum and velocity filters and a ΔE-E detector
telescope. The 8B yield was observed concurrently with the 7Be + p elastic scattering yield, relating σ(E) to the Rutherford scattering cross section. The resulting value, σ(E) = 0.41
± 0.11 μb, leads to an S(E) factor at zero energy of S(0) = 16 ± 4 eV b, in fair agreement with recommended values.
Received: 8 February 2000 相似文献
20.
A. V. Bogomyagkov V. P. Druzhinin E. B. Levichev A. I. Mil’shtein S. V. Sinyatkin 《Physics of Particles and Nuclei Letters》2018,15(7):740-744
The possibility of producing and studying thus far unobserved dimuonium atoms (μ+μ?) using low-energy colliding е+е? beams is considered. Possible collider implementations are discussed, processes affecting its efficiency are investigated, and its parameters are estimated. The collider can probably also be used for high-luminosity experiments on the study of π± and η mesons. 相似文献