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Your search keyword '"Yuan, Weizheng"' showing total 450 results
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450 results on '"Yuan, Weizheng"'

2. Super-resolution multicolor fluorescence microscopy enabled by an apochromatic super-oscillatory lens with extended depth-of-focus

Author

Li, Wenli, He, Pei, Fan, Yulong, Du, Yangtao, Gao, Bo, Chu, Zhiqin, An, Chengxu, Lei, Dangyuan, Yuan, Weizheng, and Yu, Yiting

Subjects
Physics - Optics
Abstract

Multicolor super-resolution imaging remains an intractable challenge for both far-field and near-field based super-resolution techniques. Planar super-oscillatory lens (SOL), a far-field subwavelength-focusing diffractive lens device, holds great potential for achieving sub-diffraction-limit imaging at multiple wavelengths. However, conventional SOL devices suffer from a numerical aperture (NA) related intrinsic tradeoff among the depth of focus (DoF), chromatic dispersion and focus spot size, being an essential characteristics of common diffractive optical elements. Typically, the limited DoF and significant chromatism associated with high NA can lead to unfavorable degradation of image quality although increasing NA imporves the resolution. Here, we apply a multi-objective genetic algorithm (GA) optimization approach to design an apochromatic binary-phase SOL that generates axially jointed multifoci concurrently having prolonged DoF, customized working distance (WD) and suppressed side-lobes yet minimized main-lobe size, optimizing the aforementioned NA-dependent tradeoff. Experimental implementation of this GA-optimized SOL demonstrates simultaneous focusing of blue, green and red light beams into an optical needle half of the incident wavelength in diameter at 428 um WD, resulting in an ultimate resolution better than one third of the incident wavelength in the lateral dimension. By integrating this apochromatic SOL device with a commercial fluorescence microscope, we employ the optical needle to perform, for the first time, three-dimensional super-resolution multicolor fluorescence imaging of the unseen fine structure of neurons at one go. The present study provides not only a practical route to far-field multicolor super-resolution imaging but also a viable approach for constructing imaging systems avoiding complex sample positioning and unfavorable photobleaching.

Published
2022

12. Hierarchical nested riblet surface for higher drag reduction in turbulent boundary layer.

Author

Ou, Zhaoyang, Zhou, Zidan, Zhou, Wenyuan, Wang, Daoyuan, Zhang, Kun, Kong, Zeyu, Tang, Yalin, He, Yang, and Yuan, Weizheng

Subjects
TURBULENT boundary layer, TURBULENT mixing, FLOW simulations, BOUNDARY layer (Aerodynamics), TURBULENCE, DRAG reduction
Abstract

Riblets can be potentially employed to passively reduce the turbulent friction drag. However, the drag reduction performance of riblets does not currently meet expectations, which could assist in emission reduction and energy conservation in green transportation. This study proposes and validates a topological form of hierarchical nested riblets (HNR) that significantly enhances the drag reduction performance. To explore the drag reduction enhancement mechanism, direct numerical simulations are performed for flow simulation on the riblet surface under different Reynolds numbers. The results show that under the riblet dimensionless spacing of the riblet s + ≈ 21 , the drag reduction performance of the HNR surface improves by about 70% compared to that of the uniform riblet surface, which is inspired by shark skin. From the perspective of turbulence statistics, the HNR surface reduces the turbulent mixing near the wall, weakening the momentum transfer. Furthermore, the transient flow field shows that the secondary riblet in HNR prevents some turbulent flow and streamwise vortices from entering the groove, considerably weakening the dispersive stress induced by the secondary flow. Moreover, owing to the influence of the secondary riblet, small-scale turbulence develops and strengthens into large-scale turbulent motion, which is advantageous to the boundary layer flow and results in drag reduction improvement. [ABSTRACT FROM AUTHOR]

Published
2024
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25. An optical measurement system for high precision alignment of imaging detectors

Author

Zeng, Xingchang, primary, Guan, Wei, additional, Zhao, Jin, additional, Huang, Peng, additional, Wang, Zhongqiang, additional, Zhang, Sen, additional, Zuo, Xiaozhou, additional, Xi, Gangyang, additional, Yu, Bingwei, additional, Zhang, Weiping, additional, Wang, Zhangli, additional, Zhang, Xiang, additional, Lv, Xianglian, additional, Yuan, Weizheng, additional, Wang, Xiaoxiao, additional, and He, Yang, additional

Published
2023
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49. Towards a Framework for Automatic Service Composition in Manufacturing Grid

Author

Zhang, Lei, Yuan, Weizheng, Wang, Wei, Hutchison, David, editor, Kanade, Takeo, editor, Kittler, Josef, editor, Kleinberg, Jon M., editor, Mattern, Friedemann, editor, Mitchell, John C., editor, Naor, Moni, editor, Nierstrasz, Oscar, editor, Pandu Rangan, C., editor, Steffen, Bernhard, editor, Sudan, Madhu, editor, Terzopoulos, Demetri, editor, Tygar, Dough, editor, Vardi, Moshe Y., editor, Weikum, Gerhard, editor, Zhuge, Hai, editor, and Fox, Geoffrey C., editor

Published
2005
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