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Propagation properties and radiation force of circular Airy Gaussian vortex beams in strongly nonlocal nonlinear medium 下载免费PDF全文
We study the abruptly autofocusing and autodefocusing properties of the circular Airy Gaussian vortex(CAi GV)beams in strongly nonlocal nonlinear medium for the first time through numerical simulations.The magnitude of topological charges and the position of the vortex could change not only the light spot pattern but also the intensity contrast.Meanwhile,we can change the position of the autofocusing and autodefocusing planes by changing the parameter of the incident beam.Furthermore,we can control the peak intensity contrast through choosing properly the truncation factor.As for the radiation force,we study the gradient and the scattering forces of CAi GV beams on Rayleigh dielectric sphere.Our analyses demonstrate that the radiation force can be enhanced by choosing proper parameters of CAi GV beams. 相似文献
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In accordance with nonperturbative quantum scattering theory,we investigate photoelectron angular distributions(PADs) from above-threshold detachment(ATD) of negative ions irradiated by circularly polarized few-cycle laser fields.Electrons ejected on the polarization plane demonstrate distinct anisotropies in angular distributions which distinctly vary with the carrier-envelope(CE) phase.The anisotropy is caused by interference between transition channels;it also depends strongly on laser frequency,pulse duration,and kinetic energy of photoelectrons.Optimal emission of photoelectrons,which varies with CE phase,makes it possible to control photoelectron motion. 相似文献
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为了澄清非磁性离子在不同替代位置对YBCO体系超导电性影响的物理机制,本文利用正电子湮没及相关实验手段对YBa2Cu3-x(Zn,Al)xO7-δ(x=0.0~0.4)体系进行了系统研究.结果表明,Zn对Cu(2)位的占据造成电子局域化的增强效应直接影响到了载流子的配对和有效输运,对体系的超导电性产生较强的抑制,使得Tc急剧下降;而Al对Cu-O链区域的替代则是通过对电子的弱局域化效应,最终对载流子库区产生影响,弱化了载流子向导电层CuO2面的转移,从而影响到体系的超导电性. 相似文献
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为阐明磁性离子在不同替代位置对YBCO体系超导电性的影响机制,利用正电子湮没及相关实验手段结合数值模拟,系统研究了Fe和Ni掺杂的YBa2Cu3O7-δ体系. 结果表明,Fe和Ni离子在替代过程中均以离子团簇的形式进入晶格. 当离子进入CuO2面时,由于团簇改变了周围的电子结构,造成电子的局域化,并直接影响了电子对的配对和输运,因而强烈抑制了体系的超导电性.而当掺杂离子进入Cu-O链区时,它们同样通过团簇的形式改变周围
关键词:
YBCO超导体
磁性离子替代
正电子湮没
数值模拟 相似文献
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We theoretically and experimentally study self-accelerating and self-breathing Bessel-like beams that fol- low arbitrary trajectories, including hyperbolic, hyperbolic secant, and three-dimensional (3D) spiraling trajectories. The beams have an overall Bessel-like profile in transverse dimensions; however, the intensity of their central main lobe breathes while traveling along a curved trajectory. Such beams can be readily generated experimentally through appropriate phase modulation of the optical wavefront. The beams con- tribute to the design of new families of self-accelerating beams. 相似文献
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通过静电纺丝技术制备了铜镍纳米粒子掺杂的碳纳米纤维(CuNi-CNFs),并用于过氧化氢(H_2O_2)的电分析检测。CuNi-CNFs纳米复合材料的组分、结构通过X射线衍射、拉曼光谱等方法进行了表征。该纳米复合材料中,CNFs具有较大的比表面积和良好的导电性,而CuNi纳米粒子具有良好的电催化活性。由于Cu,Ni和CNFs的协同作用,CuNi-CNFs纳米复合材料对H_2O_2表现出良好的电催化作用,传感器的线性范围为0. 01~6 mmol/L。 相似文献
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