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141.
We investigate the analytical expression of the spectrum that is produced by scattering of a polychromatic plane light wave incident upon a rotational anisotropic particle. It is found that the appearance of extrema in the frequency shift of the scattered field can be exactly predicted by our derived equations of the rotation angle. Numerical examples are presented to illustrate the theoretical results and also to show the impact of the effective radius of the scattering potential on the frequency shift. 相似文献
142.
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146.
磁旋光效应实验的旋光特性研究和数据分析 总被引:1,自引:0,他引:1
通过磁旋光效应(法拉第效应)实验,对不同物质的旋光特性有所认识。实验发现,磁旋光性物质具有左旋和右旋之分,而且它的旋光方向是由磁场的方向来决定。根据实验数据分析获得磁场强度与偏振角之关系,观察磁场电流与旋光方向的关系,进一步了解不同介质的旋光特性。 相似文献
147.
X.P. Zhou 《Theoretical and Applied Fracture Mechanics》2010,54(2):110-116
A micro-mechanics-based model is developed to investigate microcrack damage mechanism of four stages of brittle rock under rotation of the principal stress axes. They consist of linear elastic, non-linear hardening, rapid stress drop and strain softening. The frictional sliding crack model is applied to analyze microcracks nucleation, propagation and coalescence. The strain energy density factor approach is applied to determine the critical condition of microcrack nucleation, propagation and coalescence. The inelastic strain increments are formulated within the framework of thermodynamics with internal variables. Rotation of principal stress axes affect the dynamic damage constitutive relationship and the failure strength of brittle rock. 相似文献
148.
Clegg RM 《Journal of fluorescence》2006,16(6):761-771
A simple derivation is given of the expression describing the anisotropy decay of luminescence for a solution of molecules
that can only undergo rotational diffusion about a single cylindrical axis. The usual derivations of the anisotropy decay
for this cylindrical model have simply taken limiting cases of the equations resulting from the general treatment of the anisotropy
decay of a completely anisotropic rotator or the rotation of an ellipsoid. The arguments presented here can be understood
without the mathematical sophistication required to follow the general derivations for the rotational diffusion of a completely
anisotropic rotator or ellipsoids. The underlying physical mechanisms leading to a multiple exponential decay of the fluorescence
anisotropy signal from a single axis rotating cylinder are clearly shown by following this derivation. The resulting expression
for the anisotropy decay is not new. However, the derivation is easily understood, and this article is meant as an introduction
to the more advanced treatments of anisotropy decay by rotational diffusion. After presenting the derivation of the rotating
cylinder, the corresponding steps of these general treatments and this simple model are indicated. The model is of special
interest for describing the anisotropy decay resulting from rotations of proteins within membranes. 相似文献
149.
F. Willaert K. Kyllönen H. Sarkkinen H. Mäder 《Journal of Molecular Spectroscopy》2008,248(2):146-152
The pure rotational spectra of CH2DI and CHD2I have been measured by microwave Fourier transform spectroscopy, millimeterwave spectroscopy and submillimeterwave spectroscopy. The quadrupole hyperfine structure due to iodine has been analyzed by direct diagonalization of the quadrupole tensor. For the J = 1-0 transition of the ground state of CH2DI, the quadrupole hyperfine structure due to deuterium could be resolved and the quadrupole coupling constant eQqaa(D) determined.Accurate rotational and centrifugal distortion constants (up to sextic terms) have been determined. They are compared to the constants derived from the ground state combination differences (GSCD). A good agreement is observed but it is also found that the two kinds of data (GSCD and microwave) are complementary and a combined fit allows us to significantly improve the accuracy of the constants. 相似文献
150.
Horst Kessler 《Angewandte Chemie (International ed. in English)》1970,9(3):219-235
Rotations and inversions in organic molecules are readily recognizable from the temperature dependence of the NMR spectra. The study of the effects of substituents on the activation barriers of such processes permits the elucidation of reaction mechanisms, and the stability limits of isomers can also be determined. The knowledge of the stability limits is necessary for the specific synthesis of stable rotamers and invertomers. 相似文献