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811.
812.
Yue Liu 《Journal of Differential Equations》2004,203(1):159-183
Ostrovsky equation describes the propagation of long internal and surface waves in shallow water in the presence of rotation. In this model dispersion is taken into account while dissipation is neglected. Existence and nonexistence of localized solitary waves is classified according to the sign of the dispersion parameter (which can be either positive or negative). It is proved that for the case of positive dispersion the set of solitary waves is stable with respect to perturbations. The issue of passing to the limit as the rotation parameter tends to zero for solutions of the Cauchy problem is investigated on a bounded time interval. 相似文献
813.
In order to clarify the dynamical aspects of the peptide structure, N-methylpropionamide (NMPA) was investigated as an example of peptide molecules: XCONHY (X=CH3CH2 and Y=CH3 for NMPA), paying special attention to the internal rotation of the two methyl groups. NMPA was found to have an almost planar skeleton with an extended syn/trans conformation, as indicated by the observed value of Iaa+Ibb−Icc, and its rotational spectra were interpreted in terms of group G18 consisting of six symmetry species: A1, A2, E1, E2, E3, and E4. The A1 and E2 spectra were observed split in most of b-type transitions, yielding the internal-rotation potential barrier V3 of 796 (21) cm−1 for CH3 in the ethyl group referred to as C-CH3. The spectra of the three E species: E1, E3, and E4 appeared several tens to thousands MHz apart from the corresponding A1 spectra, suggesting the internal-rotation potential barrier of CH3 bonded to the nitrogen, called N-CH3, to be quite low. In sharp contrast with the A1 spectra, which were well fitted to the ordinary asymmetric-rotor spectral pattern, a few higher-order terms were required to reproduce the E1 spectra, presumably because of the low N-CH3 barrier. The spectral analysis thus performed, in fact, led to the V3 of 80.06487 (14) cm−1, an order of magnitude lower than that of C-CH3. The E3 and E4 spectra were found to form triplets with the corresponding E1 lines at the center, and the E3-E1 and E4-E1 splittings were explained essentially by the contributions of the C-CH3 internal rotation combined with the kinetic-energy coupling between the two methyl groups. The torsion around the C-C bond between the ethyl and carbonyl groups was suggested by an ab initio calculation to be of double minimum nature, but the observed A1 spectra did not show any indication of such a double-minimum potential for the C-C torsion, although the possibility of a small hump being present at a planar conformation could not be entirely eliminated. The present results on NMPA along with those obtained on other peptide molecules will be of some significance in clarifying important problems of structural biology such as protein folding and signal transfer through biological systems. 相似文献
814.
The rotation dynamics of C60 molecules in organic superconductor K3C60 has been investigated from the viewpoint of intramolecular interaction. It is determined that the rotation of C60 at mom temperature has been frozen up within a small region of rotation angle (0°–50°), and pointed out that the reason for
the freeze is the physical interaction rather than the geometrical hindrance. The computations of the interactions for alkali-doped
compounds A3-x
A′
x
C60 (x = 1, 2, 3; A, A′ = K, Rb, Cs) other than K3C60 have also been camed out. Fmm the obtained results, it is seen that the superconducting transition temperatures T, are strongly
connected with the interactions in them, and this observation is consistent with the discovery of the correlation between
Tc, and lattice constants a.
Project supported by the National Natural Science Foundation of China. 相似文献
815.
816.
MORRISON Robert C. 《物理化学学报》2018,34(3):263-269
In this work,the Fukui functions of the two ~2P resonance states of Be,a ~2P resonance state of Mg~–,and a ~2D resonance state of Ca~– have been determined.The trajectories of these resonance states,in conjunction with the complex rotation of the Hamiltonian,were used to determine their wave functions.The electron densities,Fukui functions,and values of the hyper-radiusr~2were computed from these wave functions.The Fukui functions have negative regions in the valence shell in addition to the inner shell regions,indicating screening effects of the outer temporary electron.Selected configuration interactions with up to quadruple excitations were used along the trajectories and for computing the final wave function.Based on this data,the densities,Fukui functions,andr~2were calculated. 相似文献
817.
Multiple internal reflection spectroscopy (MIRS) was applied to analyse atomic bonds at deep (500 m) interfaces of directly bonded Si/Si wafer pairs. It is shown that under the conditions used the polarized spectra contain information only about the interface layer a few nanometers thick. Examples are given of analysing the Si-H- and SiO-H vibration modes and bands of undissociated water in interfaces of bonded hydrophobic and hydrophilic wafer pairs, respectively, after annealing at temperatures between 200 and 1100 °C. Variations of the bonding behaviour (especially caused by alterations of the Si-H bonds) are discussed.Dedicated to Professor Dr. rer.nat. Dr. h.c. Hubertus Nickel on the occasion of his 65th birthday 相似文献
818.
The method described by Strobl and Hagedorn to analyze the Raman spectrum internal modes of semi-crystalline polyethylene has been applied to a set of selected polyethylene samples crystallized under controlled conditions. The crystallite structure can be described in terms of the relative amounts of the crystalline orthorhombic phase, the liquid-like amorphous phase and the interfacial region. The dependence of the level of crystallinity on molecular weight and crystallization conditions is very similar to that found by other methods. However, this method allows for the quantitative determination of the interfacial content which becomes significant for molecular weights greater than about 1×105 for linear polyethylene fractions, and for all the branched samples and copolymers. The degree of crystallinity determined from density measurements is equal to the sum of the crystallinity and interfacial content obtained from the Raman analysis while enthalpy of fusion measurements yield values which are equal to just the crystallinity content. The difference between the level of crystallinity obtained from density and enthalpy of fusion is thus found to be primarily due to interfacial contributions.Dedicated to Prof. Dr. F. H. Müller 相似文献
819.
本文根据散射内标和公共背景法的有关理论,导出了两个X-射线荧光光谱分析校正方程,将背景、基体吸收和重叠干扰校正,以及校正曲线定量分析等多种运算合并进行,因而应用起来十分简便,两个方程在数学形式上与目前使用的X-射线光谱仪计算机程序中通用的数学模型相似,便于推广应用。 相似文献
820.
高效毛细管电泳测定混合氯化稀土中的稀土元素 总被引:3,自引:0,他引:3
研究了在以含有紫外吸收的咪唑为背影电解质和以α-羟基异丁酸为络合剂的缓冲液体系中,用毛细管电泳间接外法检测和然土离子的方法,讨论了各操作条件对稀土离子分离泊影响。 相似文献