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Based on the extended Huygens-Fresnel integral,the analytic expressions for Bessel-Gaussian beams(BGBs) with optical vortices propagating in turbulent atmosphere are derived.The average intensity properties and the beam quality(Power in bucket) in the far field of Bessel-Gaussian beams with optical vortices propagating in turbulent atmosphere are investigated.It is found that intensity profiles of Bessel-Gaussian beams experienced successive variations and the phase singularity rapidly fades away during propagating in turbulent atmosphere.The process is closely related with the number of topological charge,the beam′s waist width and the strength of atmospheric turbulence.The maintenance of singularity of vortex beams with larger topological charge in turbulent atmosphere is better than that for vortex beams with smaller topological charge.In addition,based on the theory of power in bucket,the influence of topological charge,the beam′s waist width and the strength of atmospheric turbulence on the beam quality of Bessel-Gaussian beams is explored in detail.

运用密度泛函理论计算了氧（O）在Nb3Ge表面的吸附，结果表明O倾向于吸附在Nb原子周围，并与Nb的电子轨道发生了明显的交叠，O与Nb形成兼具共价键和离子键特性的化学键。利用X射线光电子能谱对自然氧化的Nb3Ge表面进行成分分析发现：氧化层中只存在Nb的氧化物，理论计算结果与实验结果一致。由于O容易与Nb结合，最外层的Nb因逐渐氧化而耗尽，在接触势的驱使下，内部的Nb原子与最外层的Ge原子交换，最终使得Nb与O的形成氧化物在Nb3Ge表面聚集，在该氧化层下面是由于Nb的耗尽而形成的Ge聚集层。