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41.
B. Saha A.K. Das P.K. Mukherjee 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,14(1):33-37
Transition energies, oscillator strengths and transition probability values for radiative transitions have been calculated
for the highly ionised atoms of Si isoelectronic sequence from Mn11+ to Kr22+ for the singly excited states up to principal quantum number n = 7. Time-dependent coupled Hartree-Fock (TDCHF) theory has been used to estimate such transition properties. Most of the
results for the oscillator strengths and transition probabilities are new. Transition energies agree reasonably well with
available spectroscopic values.
Received 25 January 2000 and Received in final form 24 October 2000 相似文献
42.
Z.G. Zhang Z.S. Li S. Svanberg P. Palmeri P. Quinet E. Biémont 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2001,15(3):301-305
Lifetimes of three levels belonging to the configuration 4f
135d with J = 1 in Yb III have been measured for the first time using the time-resolved laser-induced fluorescence method. Experimental
transition probabilities have been deduced for the transitions between the levels studied and the ground state. The comparison
of the experimental lifetimes with theoretical data, deduced within the relativistic Hartree-Fock (HFR) approach, underlines
the dramatic importance of an adequate consideration of core-polarization effects in the theoretical model and the sensitivity
of one of the lifetime values to small correlation effects.
Received 2 April 2001 相似文献
43.
Experimental data on masses and lifetimes of unstable particles falls into a pattern, a brief review of some interesting consequences
is presented here. From the experience in semiclassical methods and recent advances in quantum chromodynamics, it is proposed
that an appropriate generalization of the Gutzwiller trace formula for field theories may lead to a systematic semiclassical
chromodynamics theory. The theory can be developed to get appropriate dynamics leading to an explanation of pattern discovered
in the empirical data. 相似文献
44.
The energy of gamma rays emitted after thermal neutron capture can nowadays be measured with parts-per-million precision. This precision allows one to measure tiny Doppler effects caused by recoil due to the preceding emission of gamma rays or neutrinos. The study of the Doppler profiles of gamma rays has given rise to new applications in nuclear and solid state physics 相似文献
45.
G. Dominiak‐Dzik W. Ryba‐Romanowski R. Lisiecki I. Fldvri 《Crystal Research and Technology》2007,42(12):1335-1340
Single crystal of bismuth tellurite Bi2TeO5 (BTO) doped with trivalent thulium (Tm3+) was grown by the Czochralski method and investigated by spectroscopic techniques (absorption, emission). Absorption and emission of the Tm:BTO crystal collected in the VIS‐IR spectral range are presented. Spectroscopic features were investigated as a function of the excitation light polarisation (E//X, Y, and Z axis of optical indicatrix) and sample temperature. The oscillator strength of the 3H6 → 3F4 transition at 1.7 μm was determined by numerical integration of the X, Y and Z polarised absorption spectra. The obtained values are: PX = 4.7 × 10−6, PY = 6.8 × 10−6 and PZ = 5.9 × 10−6 that gives a mean value Pmean = 5.8 × 10−6. Emission was observed from the 1G4 and 3H4 levels. The 3H4 and 1G4 excited state dynamics was studied. Decay curves and time constants of luminescence were collected at 5 and 300 K and analysed. The 3F4 → 3H6 luminescence at around 1.8 μm was too weak to be acquired from the low concentrated sample. However, based on optical data it was possible to estimate the radiative probability Arad of this transition and the 3F4 radiative lifetime. The resultant values are: Arad = 668 ± 0.4 s−1 and τrad = 1.5 ms. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
46.
Dr. Ryoichi Ishimatsu Dr. Tomohiko Edura Prof. Chihaya Adachi Prof. Koji Nakano Prof. Toshihiko Imato 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(14):4889-4898
The photophysical properties and electrogenerated chemiluminescence (ECL) of three donor–acceptor molecules composed of dicyanobenzene and methyl‐, tert‐butyl‐, and phenyl‐substituted carbazolyl groups, 1,2,3,5‐tetrakis(3,6‐disubstituted‐carbazol‐9‐yl)‐4,6‐dicyanobenzene (4CzIPN‐Me, 4CzIPN‐tBu, and 4CzIPN‐Ph, respectively) are described. These molecules show delayed fluorescence as a result of thermal spin upconversion from the lowest triplet state to the lowest singlet state at room temperature. The three molecules showed yellow to yellowish–red ECL. Remarkably, the ECL efficiencies of 4CzIPN‐tBu in dichloromethane reached almost 40 %. Moreover, stable ECL was emitted from 4CzIPN‐tBu and 4CzIPN‐Ph. In case of 4CzIPN‐Me, the ECL intensity decreased during voltage cycles because of polymerization. Quantum chemical calculations revealed that polymerization was inhibited by the steric hindrance of the bulky tert‐butyl and phenyl groups on the carbazolyl moieties and lowered the spin density on the carbazolyl groups through electron conjugation for 4CzIPN‐Ph. 相似文献
47.
采用紫外可见吸收、稳态荧光光谱和荧光衰减测量技术,观察了4-硝基-4'-氨基偶氮苯(NAA)在氯仿溶液中的光致变色现象及分子的跃迁能级和能级寿命。结果表明:NAA分子的顺反异构化反应并非一级反应;分子处于反式异构体和顺式异构体的跃迁能分别为255.6,240.2 kJ/mol;分子处于反式异构体的能级寿命为0.02 ns,处于顺式异构体的能级寿命为3.54 ns。顺反异构体的含量、NAA分子之间及NAA分子与溶剂分子之间的相互作用影响NAA分子激发态的能级寿命。 相似文献
48.
采用考虑Davidson修正的内收缩多参考组态相互作用(icMRCI+Q)方法结合相关一致基组aug-ccpV5Z和aug-cc-pV6Z计算了CF~+离子第一离解极限C~+(~2p_u)+F(~2P_u)对应的12个∧-S态(X~l∑~+,a~3∏,1~3∑~+,1~3Δ,1~1∑~-,1~1∑~-,1~3∑~-,2~1∑~+,1~1∏,2~3∏,2~1∏和2~3∑~+)所产生的23个Ω态的势能曲线.计算中考虑了旋轨耦合效应、核价相关和标量相对论修正以及将参考能和相关能分别外推至完全基组极限.基于得到的势能曲线,获得了束缚和准束缚的9个∧-S态和16个Ω态的光谱常数,并且X~1∑~+,a~3∏~(势阱一)∧-S态的光谱常数与已有的实验结果非常符合.此外,计算了CF自由基X~2∏态到CF~+离子束缚和准束缚的9个∧-S态的垂直电离势和绝热电离势,并且CF~+(X~1∑~+)←CF(X~2∏)和CF~+(a~3∏(势阱一))←CF(X~2∏)的垂直电离势和绝热电离势与相应的实验结果也非常符合.由a~3∏,1~1∏态和其他激发∧-S态势能曲线的交叉现象,借助于计算的旋轨耦合矩阵元,分析了a~3∏~(势阱一),1~1∏~(势阱一)和2~1∑~+态的预解离机理.计算的23个Ω态离解极限处的相对能量与实验结果十分吻合.最后计算了(2)0+~(势阱一)(v'=0-5),(1)1~(势阱一)(v'=0-5)和(2)1~(势阱一)(v'=0)到X0~+态跃迁的Franck-Condon因子和辐射寿命. 相似文献
49.
M. Kimura L. Pichl Y. Li H.-P. Liebermann R. J. Buenker I. F. Schneider 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(1):85-91
The positive water and hydronium ions are of interest in a
variety of chemical and biological applications. Here we study the
steric effect in charge transfer collisions, i.e. the spatial
dependence of single electron capture, in collisions mediated by
these ions. In particular, the steric effect is demonstrated in the
O+(2D)/H2 and H+/H2O charge transfer collisions in
the energy range of 100 eV/amu to 10 keV/amu. 相似文献
50.
M. Yamazaki N. Kishimoto K. Ohno 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(1):47-57
Collisional ionization of styrene (phenylethylene), 2-vinylpyridine, and
4-vinylpyridine with metastable He*(23S) atoms were studied by means of
collision-energy/electron-energy resolved two-dimensional Penning
ionization electron spectroscopy. Collision energy dependence of partial
ionization cross-sections, which reflects the anisotropic interactions
between a He*(23S) atom and the target molecules, indicates that
attractive interaction for the out-of-plane access of a He*(23S) atom
to phenyl group is stronger than that for the out-of-plane access to vinyl
group. Moreover, it was found for vinylpyridines that the attractive
interaction around π electrons became weaker than that for styrene, and
that the attractive interaction for the in-plane access to the nitrogen atom
is stronger than that for out-of-plane π-directions. However, in
2-vinylpyridine, the hydrogen atom of vinyl group prevents a He*(23S)
atom from approaching to the nitrogen atom along in-plane directions, and
thus the attractive interactions around the nitrogen atom were shielded by
the vinyl group. The experimentally observed anisotropic interactions were
qualitatively supported with ab initio model interaction potential calculations
between a Li (He*(23S)) atom and the target molecule. Concerning with
electronic structures of investigated molecules, the assignment of Penning
ionization electron spectrum for 4-vinylpyridine was discussed on the basis
of different behavior of collision-energy dependence of partial ionization
cross-sections, and the satellite ionization band in Penning ionization
electron spectra was also reported for styrene. 相似文献