scholarly journals Spiral autofocusing Airy beams carrying power-exponent-phase vortices

2014 ◽  
Vol 22 (7) ◽  
pp. 7598 ◽  
Author(s):  
Peng Li ◽  
Sheng Liu ◽  
Tao Peng ◽  
Gaofeng Xie ◽  
Xuetao Gan ◽  
...  
Keyword(s):  
2021 ◽  
pp. 127635
Author(s):  
Jinfu Zeng ◽  
Qinlang Zhang ◽  
Xuejuan Liu ◽  
Yan Chen ◽  
Yiping Xu ◽  
...  
Keyword(s):  

Author(s):  
Qian Huang ◽  
Mengting Zhang ◽  
Siyu Tu ◽  
Kejia Wang ◽  
Zhengang Yang ◽  
...  
Keyword(s):  

Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 320-328
Author(s):  
Delin Sun ◽  
Minggao Zhu

Abstract In this paper, the energy dissipation in a bolted lap joint is studied using a continuum microslip model. Five contact pressure distributions compliant with the power law are considered, and all of them have equal pretension forces. The effects of different pressure distributions on the interface stick-slip transitions and hysteretic characteristics are presented. The calculation formulation of the energy dissipation is introduced. The energy dissipation results are plotted on linear and log-log coordinates to investigate the effect of the pressure distribution on the energy distribution. It is shown that the energy dissipations of the lap joints are related to the minimum pressure in the overlapped area, the size of the contact area and the value of the power exponent. The work provides a theoretical basis for further effective use of the joint energy dissipation.


Nanophotonics ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Qingqing Cheng ◽  
Juncheng Wang ◽  
Ling Ma ◽  
Zhixiong Shen ◽  
Jing Zhang ◽  
...  

AbstractAiry beams exhibit intriguing properties such as nonspreading, self-bending, and self-healing and have attracted considerable recent interest because of their many potential applications in photonics, such as to beam focusing, light-sheet microscopy, and biomedical imaging. However, previous approaches to generate Airy beams using photonic structures have suffered from severe chromatic problems arising from strong frequency dispersion of the scatterers. Here, we design and fabricate a metasurface composed of silicon posts for the frequency range 0.4–0.8 THz in transmission mode, and we experimentally demonstrate achromatic Airy beams exhibiting autofocusing properties. We further show numerically that a generated achromatic Airy-beam-based metalens exhibits self-healing properties that are immune to scattering by particles and that it also possesses a larger depth of focus than a traditional metalens. Our results pave the way to the realization of flat photonic devices for applications to noninvasive biomedical imaging and light-sheet microscopy, and we provide a numerical demonstration of a device protocol.


2020 ◽  
Vol 102 (6) ◽  
Author(s):  
Zihao Pang ◽  
Xiaoyan Zhou ◽  
Zhenglin Liu ◽  
Daomu Zhao

2003 ◽  
Vol 67 (1) ◽  
pp. 115-119
Author(s):  
Alireza Abdollahi

Let c ≥ 0, d ≥ 2 be integers and be the variety of groups in which every d-generator subgroup is nilpotent of class at most c. N.D. Gupta asked for what values of c and d is it true that is locally nilpotent? We prove that if c ≤ 2d + 2d−1 − 3 then the variety is locally nilpotent and we reduce the question of Gupta about the periodic groups in to the prime power exponent groups in this variety.


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