共查询到20条相似文献,搜索用时 15 毫秒
1.
R. F. Tuktarov R. V. Khatymov P. V. Shchukin M. V. Muftakhov V. Yu. Markov O. A. Solomeshch 《JETP Letters》2009,90(7):515-518
The mean lifetimes of negative molecular ions of C60 fullerene and its fluoroderivatives C60F18 and C60F36 with respect to the autodetachment of electrons have been measured as functions of the ionizing electron energy by the method
of mass spectrometry of electron resonance capture. The lifetimes of negative ions in the compounds under investigation are
within the one-second range, and an increase in the number of addends leads to an increase in the lifetimes of negative ions
by 1.5–2.5 orders of magnitude. 相似文献
2.
许雪松 《原子与分子物理学报》2006,23(1):137-142
应用密度泛函B3LYP/6-31 G(d,p)方法对C8H8O-(H2O)n(n=1~5)团簇这种弱相互作用体系进行全自由度能量梯度优化,得到该系列团簇的稳定结构.计算结果表明,在该系列二元团簇中,一方面水分子数目的多少对苯基丙酮分子的结构影响很小,另一方面由于苯基丙酮分子的存在,破坏了团簇中水分子的对称性结构,在团簇内部极力形成O-H-O这样弯曲的有方向性的氢键.对苯基丙酮-水这样结构复杂的团簇,指认光谱的难度非常大,本文只讨论了与C=O有关的振动峰和水分子的对称伸缩振动的最强峰. 相似文献
3.
合成了新的Eu(C8H7O3)3·C12H8N2·H2O配合物.并经元素分析、摩尔电导、IR、UV、1H NMR等表征,初步确定配体3-甲氧基苯甲酸以桥式双齿形式和Eu(Ⅲ)配位. 相似文献
4.
Veličković SR Đustebek JB Veljković FM Veljković MV 《Journal of mass spectrometry : JMS》2012,47(5):627-631
Clusters of the type Li(n)X (X = halides) can be considered as potential building blocks of cluster-assembly materials. In this work, Li(n)Br (n = 2-7) clusters were obtained by a thermal ionization source of modified design and selected by a magnetic sector mass spectrometer. Positive ions of the Li(n)Br (n = 4-7) cluster were detected for the first time. The order of ion intensities was Li(2)Br(+) > Li(4)Br(+) > Li(5)Br(+) > Li(6)Br(+) > Li(3)Br(+). The ionization energies (IEs) were measured and found to be 3.95 ± 0.20 eV for Li(2)Br, 3.92 ± 0.20 eV for Li(3)Br, 3.93 ± 0.20 eV for Li(4)Br, 4.08 ± 0.20 eV for Li(5)Br, 4.14 ± 0.20 eV for Li(6)Br and 4.19 ± 0.20 eV for Li(7)Br. All of these clusters have a much lower ionization potential than that of the lithium atom, so they belong to the superalkali class. The IEs of Li(n)Br (n = 2-4) are slightly lower than those in the corresponding small Li(n) or Li(n)H clusters, whereas the IEs of Li(n)Br are very similar to those of Li(n) or Li(n)H for n = 5 and 6. The thermal ionization source of modified design is an important means for simultaneously obtaining and measuring the IEs of Li(n)Br (n = 2-7) clusters (because their ions are hermodynamically stable with respect to the loss of lithium atoms in the gas phase) and increasingly contributes toward the development of clusters for practical applications. 相似文献
5.
6.
Jun Feng YanLin Ye Biao Yang ChengJian Lin HuiMin Jia DanYang Pang ZhiHuan Li JianLing Lou QiTe Li XiaoFei Yang Jing Li HongLiang Zang Qiang Liu Wei Jiang ChenGuang Li Yang Liu ZhiQiang Chen HongYi Wu ChunGuang Wang Wei Liu Xiang Wang JingJing Li DiWen Luo Ying Jiang ShiWei Bai JinYan Xu NanRu Ma LiJie Sun DongXi Wang 《中国科学:物理学 力学 天文学(英文版)》2019,(1)
The inelastic excitations and cluster decay of ~(13)C have been measured using the reaction,9Be(~(13)C, ~(13)C* →~9Be + α)~9Be. We observe strong excitation to the 14.3-MeV(1/2-) resonant state from the cluster-decay channel, leading to an enhanced monopole matrix element of(6.3 ± 0.6) fm~2. This large cluster-related monopole strength is a clear indication of the cluster-structure domination of this state and is consistent with the recent prediction of the orthogonality condition model(OCM). It would be interesting to further explore the three-center molecular rotational band that is initiated from the observed band-head. 相似文献
7.
8.
《Nuclear Physics A》1999,646(3):387-396
The 3He(3He,2p)4He and 3H(3H,2n)su4He reactions are studied in a microscopic cluster model. We search for resonances in the 3He+3He and 4He + p + p channels using methods that treat the two- and three-body resonance asymptotics correctly. Our results show that the existence of a low-energy resonance or virtual state, which could influence the 7Be and 8B solar neutrino fluxes, is rather unlikely. Our calculated 3He(3He,2p)4He and 3H(3H,2n)4He cross sections are in a good general agreement with the experimental data. 相似文献
9.
The yield of H(+) in the metastable He*(2(3)S, 1s2s) stimulated desorption (MSD) on an H2O/Na/Fe surface has been found to depend on the spin of the incident He*. By combination with the spin-resolved analysis for the surface electronic structure, it is indicated that the neutralization of the hole in the OH 3 sigma molecular orbital, which is created by the incident He*, by Na 3s electrons plays a crucial role in the spin polarization of the H (+) MSD intensity. The dependence of the spin polarization of H(+) MSD on the kinetic energy of the desorbed H(+) has been observed, and it is discussed based on the Menzel-Gomer-Readhead model. 相似文献
10.
《Nuclear Physics A》1988,486(2):285-305
11.
《中国物理 B》2015,(6)
The values of cross-section ratio Rk1 of direct k-fold ionization cross section(σk) to direct single ionization cross section(qσ1) of Ne impacted by C+(q = 1–3) ions in an energy range of 10 ke V/u–500 ke V/u are measured in this work.The experimental data are compared with the results from our multi-electron classical over-barrier ionization(ME-COBI)model,showing that the model can give a good estimate to the experimental data. 相似文献
12.
E. Holub N. Cindro O. Bersillon J. Jary 《Zeitschrift für Physik A Hadrons and Nuclei》1979,289(4):421-431
The (n, 2n) cross sections for about 80 nuclei ranging fromA=45 to 209 were calculated using the evaporation model. The calculation was performed for incident energiesE n which satisfy the conditionU R =E n +Q n ,2n=6±1 MeV. For 11 nuclei in the above mass region, (n, 2n) excitation functions were calculated from threshold to 20 MeV. In all calculations a single set of input parameters was consistently used. The influence of the level-density parameter and neutron cross sections on the evaporation model was tested. All calculated results were compared with experimental data. The systematic discrepancy between experimental data and evaporation calculations leads to the necessity of introducing the preequilibrium emission mechanism. 相似文献
13.
R. Muhida M. David M. M. Rahman W. A. Diño H. Nakanishi H. Kasai K. Fukutani T. Okano 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,38(1):99-101
We investigate the molecular orientation dependence of the (o)rtho-(p)ara H2 conversion on Fe(OH)3 cluster. Taking Fermi's contact interaction as perturbation, we find that the o-p H2 conversion yield for the molecular orientation angle θ= 10○ with respect to the surface normal is larger than that for θ= 70○. 相似文献
14.
基于密度泛函理论的第一性原理计算方法,本文对ConAgm(n+m=13)团簇的几何结构进行优化后,研究了C2H4分子在这类团簇的表面吸附行为,讨论了团簇的平均结合能、二阶能量差分、稳定性、DOS以及吸附前后键长的变化情况。结果表明,C2H4在团簇top位的吸附主要为物理吸附,而在face位和bridge位的吸附主要为化学吸附。吸附后,C2H4@Ag13的稳定性高于C2H4@Co13,且在face位吸附时C2H4@Co2Ag11的结构最为稳定。随着Co原子数的增加,团簇中原子间成键能力减弱,而d电子轨道则呈现出较强的相互作用,并导致其向能量相对高处发生转移 相似文献
15.
16.
本以α-呋喃甲酸(C5O3H4)和邻菲罗啉(C12H8N2)为配体,在乙醇8溶剂中与硝酸镧反应,合成了与稀土离子La(Ⅲ)的三元混配配合物。经元素分析确定其配合物的组成为La(C5O3H3)·C12H8N2·H2O,同时还通过了IR、^1HNMR、UV、TG-DTA等谱光的测试与分析,表征了配合物的组成结构和性质。IR、^1HNMR和UV谱的分析结果表明配体羧酸是以脱质子的酸根形式与中心稀土离子 相似文献
17.
《Physica B+C》1977,86(1):79-84
A renormalized spin-wave theory is developed for the layer-type ferromagnet (C3H7NH3)2CuCl4. In contrast with the case of K2CuF4, the main perturbation to the isotropic intralayer exchange interaction leading to three-dimensional long-range order is here the anisotropy in the intraplanar interaction. An analytical expression for the magnetization of the two-dimensional Heisenberg ferromagnet with a weak anisotropy in the intraplanar exchange as well as interplanar interactions has been obtained. It is shown that an excellent agreement between theory and experiment can be obtained using the interaction constants estimated in previous investigations, and further that the spin-wave interactions have a significant effect on the temperature dependence of the magnetization. 相似文献
18.
M. Mitsui Y. Matsumoto N. Ando A. Nakajima 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2005,34(1-3):169-172
Cluster anions of 2,2’-bithiophene, (2T)n-, were produced up
to n ∼500 in the gas-phase. The energetics of the excess electron in
the (2T)n- clusters with n =1-100 were explored by
negative ion photoelectron spectroscopy. When the vertical detachment
energies (VDEs) obtained from the photoelectron spectra were analyzed by a
plot against n-1/3, it has been revealed that the excess electron
trapping level thus extrapolated is located at ∼0.8 eV below the
conduction band minimum (i.e. LUMO) of the 2T thin film. The large slope of
the VDEs vs. n-1/3 plot suggests that the neutral 2T molecules
surrounding the anion core take non-planar twisted conformations with
permanent dipole moments, resulting in the exceedingly deep trapping of the
excess electron in the 2T cluster anions. 相似文献
19.
The possibility to construct intercluster interaction potentials in continuous and discrete spectra is shown in one‐channel cluster model based on the classification of orbital states according to Young schemes. These potentials usually contain Pauli forbidden states, and correctly describe elastic scattering phase shifts taking into account resonance behavior and main characteristics of the bound states of nuclei in the considering cluster channel. The versions of intercluster interaction potentials describing the resonance nature of some phase shifts of the n7Li elastic scattering at low energies and the P2 ground state of 8Li in the n7Li cluster channel have been constructed for the demonstration of this approach. The possibility of describing the total cross sections of 7Li (n,γ)8Li within the energies from 5 meV (5 · 10‐3 eV) to 1 MeV, including resonance at 0.25 MeV, has been demonstrated for the potentials obtained in the potential cluster model with forbidden states. 相似文献
20.
本文采用密度泛函理论方法,研究了氢气分子在硼取代富勒烯C19Bn+(n=0-3)表面的非解离吸附态、化学吸附态、及吸附态之间转换过渡态的结构和能量,得到了吸附态之间转换反应的势能面. 研究表明通过调整体系的离子化电荷可以调整吸附位点的电荷布居数,随着硼取代富勒烯离子化体系C19Bn+的吸氢活性位点电荷布居数增大,氢分子被极化的程度以及氢分子在材料表面的吸附能均逐渐增大,同时改变电荷布居数也对氢气分子在表面吸附态间转变势垒高度产生了量级为几个Kcal/mol的影响. 希望我们的研究能够对富勒烯储氢的进一步发展提供参考. 相似文献