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991.
V.P. Nayyar 《Optical and Quantum Electronics》2002,34(7):697-705
Using statistical approach the author has solved the equations for the mutual coherence function of partially coherent Gaussian laser beams in graded-index fibres. The expressions for the complex degree of coherence and the intensity distribution have also been shown that the self-focusing length inside the fibre depends upon the degree of coherence. The result have been discussed for both conical and cylindrical guides. 相似文献
992.
993.
用YAG激光制备类金刚石薄膜及其光学折射率研究 总被引:2,自引:2,他引:0
用高功率的Nd^3+:YAG脉冲激光轰击真空室内的石墨靶,形成激光等离子体雾状物质,在硅衬底上沉积形成类金刚石薄膜,用椭圆偏振光谱法测量不同衬底温度下制备的系列样品的厚度和折射率,发现随着衬底温度的升高,薄膜的厚度减小而的折射率增大,这种可以控制折射率米化的薄膜,可能为光学增透增反膜的制备提供一种新方法。 相似文献
994.
995.
Chun Gen Liu 《数学学报(英文版)》2005,21(2):237-248
In this paper, we consider the relation of the Morse index of a closed geodesic with
the Maslov–type index of a path in a symplectic group. More precisely, for a closed geodesic c on
a Riemannian manifold M with its linear Poincaré map P (a symplectic matrix), we construct a
symplectic path γ(t) starting from identity I and ending at P, such that the Morse index of the closed
geodesic c equals the Maslov–type index of γ. As an application of this result, we study the parity of
the Morse index of any closed geodesic.
Project 10071040 supported by NNSF, 200014 supported by Excellent. Ph.D. Funds of ME of China, and PMC
Key Lab. of ME of China 相似文献
996.
Dispersive two-beam Fourier interferograms of N2-gas in the visible wave number range are calculated numerically for nonabsorbing as well as absorbing gas and compared with experiment. Some problems of inverse Fourier transformation of dispersive interferograms are also discussed. 相似文献
997.
998.
The chemistry of N2H4 on Si(100)2 × 1 and Si(111)7 × 7 has been studied using scanning tunneling microscopy. At low coverages on Si(100)2 × 1 at room temperature the adsorption sites are distributed randomly on the surface and are imaged as dark spots in the dimer row by the STM. Upon annealing the substrate at 600 K, both isolated reaction products, as well as clusters of reaction products are formed on the surface. The STM images show that the majority of the isolated reaction products are adsorbed symmetrically across the dimers. Based on previous HREELS data, these are most likely NHx groups. However, the clusters are not well resolved. Because of this we speculate that they are not simply symmetrically adsorbed NHx groups, but likely have a more complicated internal structure. At higher coverages, the STM images show that the predominant pathway for adsorption is with the N---N bond parallel to the surface, in agreement with HREELS studies of this system. On Si(111)7 × 7, the molecule behaves in a manner which is similar to NH3. That is, at low coverages the molecule adsorbs preferentially at center adatoms due to the greater reactivity of these sites, while at higher coverages it also reacts with the corner adatoms. 相似文献
999.
1000.