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991.
提出一个根据拉曼基频模及其倍频模的斯托克斯和反斯托克斯拉曼成分的不同共振行为来探测样品与激光共振的系统能级的方法.此方法被应用到不均匀单壁碳纳米管束样品中某一径向呼吸模频率为219波数的金属型碳纳米管.通过分析呼吸模及其倍频模和切向模的共振行为,获得了该碳纳米管的电子跃迁能量,并获得纳米管C-C最近邻重叠积分因子为2.80 eV.此数值可以很好的解释单壁碳纳米管径向呼吸模的共振行为.
关键词:
单壁碳纳米管
呼吸模
共振拉曼散射
电子跃迁能 相似文献
992.
993.
994.
Least-squares forecasts for vibration frequencies of diatomic molecules, most with 10–12 valence electrons, are combined with those obtained from neural networks, both trained on critical data. It is required that the standard deviation bounds of the one prediction lie within the bounds of the other; this requirement results in 69 molecules, 50 of which may not have been studied before. The composite standard deviations of the composite predictions average 5.9%, so there is a 68% chance that each of these 50 predictions will prove to be within 5.9% of its ultimately correct value. As a test, 28 literature values, for 12 of the molecules, were found; of these 28 values, 78.6% fall between the lower and upper composite standard deviation limits. 相似文献
995.
Robynne Kirkpatrick Narumol Jariyasopit Joseph W. Nibler Arthur Maki Timothy Hubler 《Journal of Molecular Spectroscopy》2008,248(2):153-160
The infrared spectrum of [1.1.1]propellane has been recorded at high resolution (0.002 cm−1) with individual rovibrational lines resolved for the first time. This initial report presents the ground state constants for this molecule determined from the analysis of five of the eight infrared-allowed fundamentals ν9(e′), ν10(e′), ν12(e′), , as well as of several combination bands. In nearly all cases it was found that the upper states of the transitions exhibit some degree of perturbation but, by use of the combination difference method, the assigned frequencies provided over 4000 consistent ground state difference values. Analysis of these gave for the parameters of the ground state the following values, in cm−1: B0 = 0.28755833(14), DJ = 1.1313(5) × 10−7, DJK = −1.2633(7) × 10−7, HJ = 0.72(4) × 10−13, HJK = −2.24(13) × 10−13, and HKJ = 2.25(15) × 10−13, where the numbers in parentheses indicate twice the uncertainties in the last quoted digit(s) of the parameters. Gaussian ab initio calculations, especially with the computed anharmonic corrections to some of the spectroscopic parameters, assisted in the assignments of the bands and also provided information on the electron distribution in the bridge-head carbon-carbon bond. 相似文献
996.
HAN Yin-Xia LI Jing-Hui 《理论物理通讯》2008,49(2):385-390
The phenomenon of the resonant activation (RA) of a particle over a fluctuating potential barrier with a four-value noise is investigated. It is shown that the mean first passage time (MFPT) displays six minima as the function of the transition rates γ1, γ2, γ3, γ4, γ5, and 76 of the four-value noise, respectively. In addition, the effect of other parameters of the system, such as the noise strength D of the additive Gaussian white noise and the parameter value a, b, c, and d of the four-value noise, on the RAs is also investigated. 相似文献
997.
JIANG Zhan-Feng LI Hong 《理论物理通讯》2008,50(12):1453-1456
A on,dimensional ring subject to Rashba spin-orbit coupling is investigated. When it is attached to a lead with spin-dependent chemical potential, there will be charge current in the ring. The charge current response is resonantly maximized when the Fermi energy of the lead is equal to any energy level of the 1D ring. And if two probes are attached to the ring, the electric voltage between them creates sawtooth-like wave, which indicates the direction of the charge current. A ferromagnetic lead can also induce persistent charge current, which can be detected by magnetization intensity measurement. 相似文献
998.
U. Staub V. Scagnoli Y. Bodenthin M. García‐Fernández R. Wetter A. M. Mulders H. Grimmer M. Horisberger 《Journal of synchrotron radiation》2008,15(5):469-476
An experimental approach to the analysis of charge, magnetic and orbital ordering in 3d transition‐metal oxides is presented. The technique combines two important components: azimuthal rotations around the Bragg wavevector and polarization analysis of the Bragg intensities in the range 500–900 eV. The polarization analysis is performed using graded multilayers, which are translated and rotated in the vacuum chamber. It is shown why these two components are important to determine the origin of the Bragg scattered signals and how they allow us to separate the different contributions. Examples are given for the oxygen K and the Mn, Co, Ni and Cu L2,3‐edges, and the advantages and drawbacks of this experimental technique are discussed. 相似文献
999.
两轴四框架结构光电稳瞄吊舱减振器谐振频率计算与试验 总被引:2,自引:1,他引:1
根据振动理论分析两轴四框架系统选择减振器的要点,对某型直升机内外框架刚性连接的吊舱进行扫频振动试验,测量了谐振频率和谐振点的扫频放大率,绘制了放大率曲线。通过使用放大率曲线计算内外框架刚性连接时系统的三向刚度。并根据减振器刚度值,利用弹簧串联刚度的计算方法计算了使用减振器系统的三向刚度和谐振频率。重新进行试验后,结果表明系统谐振频率和放大率都满足要求。该结构使用减振器的要点是:减振器放大段位于伺服带宽内,系统谐振频率避开外界扰动频率以及放大率应尽可能小。 相似文献
1000.
Solvability for Riemann-Stieltjes integral boundary value problems of Bagley-Torvik equations at resonance
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In this paper, we study the solvability for Riemann-Stieltjes integral boundary value problems of Bagley-Torvik equations with fractional derivative under resonant conditions. Firstly, the kernel function is presented through the Laplace transform and the properties of the kernel function are obtained. And then, some new results on the solvability for the boundary value problem are established by using Mawhin''s coincidence degree theory. Finally, two examples are presented to illustrate the applicability of our main results. 相似文献