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Your search keyword '"Zhou, Yueming"' showing total 115 results
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115 results on '"Zhou, Yueming"'

1. Circularly polarized RABBIT applied to a Rabi-cycling atom

Author

Liao, Yijie, Olofsson, Edvin, Dahlström, Jan Marcus, Pi, Liang-Wen, Zhou, Yueming, and Lu, Peixiang

Subjects
Physics - Atomic Physics
Abstract

We utilize the reconstruction of attosecond beating by interference of two-photon transitions (RABBIT) technique to study the phase of a Rabi-cycling atom using circularly polarized extreme ultraviolet and infrared (IR) fields, where the IR field induces Rabi oscillations between the 2s and 2p states of lithium. Autler-Townes splittings are observed in sidebands of the photoelectron spectra and the relative phases of outgoing electron wave packets are retrieved from the azimuthal angle. In this RABBIT scheme, more ionization pathways beyond the usual two-photon pathways are required. Our results show that the polar-angle-integrated and polar-angle-resolved RABBIT phases have different behaviors when the XUV and IR fields have co- and counter-rotating circular polarizations, which are traced back to the different ionization channels according to the selection rules in these two cases and their competition relying on the propensity rule in laser-assisted photoionization.

Published
2023

4. Magnetic-Field effect in Laser-assisted XUV ionization

Author

Liang, Jintai, Zhou, Yueming, Jiang, Wei-Chao, Li, Min, and Lu, Peixiang

Subjects
Physics - Atomic Physics
Abstract

The magnetic-field effect of the laser pulse is investigated in laser-assisted XUV ionization. By numerically solving the three-dimensional time-dependent Schr\"odinger equation, we find that the photoelectron momentum distribution is distorted by the magnetic-field effect of the IR streaking field. It results in a transverse-momentum- and time-delay-dependent longitudinal photoelectron momentum shift, which is further analytically confirmed by employing the nondipole corrected strong field approximation. We also demonstrate that the magnetic field does not affect the time shift retrieved from the streaking spectrum, although the streaking spectrum is apparently altered by the momentum shift induced by the magnetic-field effect. Our work reveals the time-resolved nondipole effect of the laser pulse by the attosecond streaking technique.

Published
2022

7. Proton tunneling in the dissociation of H2+ and its asymmetric isotopologues driven by circularly polarized THz laser pulses.

Author

Tian, Yidian, Liu, Kunlong, Wang, Yuchen, Zhou, Yueming, and Lu, Peixiang

Abstract

Light-induced deprotonation of molecules is an important process in photochemical reactions. Here, we theoretically investigate the tunneling deprotonation of H 2 + and its asymmetric isotopologues driven by circularly polarized THz laser pulses. The quasi-static picture shows that the field-dressed potential barrier is significantly lowered for the deprotonation channel when the mass asymmetry of the diatomic molecule increases. Our numerical simulations demonstrate that when the mass symmetry breaks, the tunneling deprotonation is significantly enhanced and the proton tunneling becomes the dominant dissociation channel in the THz driving fields. In addition, the simulated nuclear momentum distributions show that the emission of the proton is directed by the effective vector potential for the deprotonation channel and, meanwhile, the angular distribution of the emitting proton is affected by the alignment and rotation of the molecule induced by the rotating field. [ABSTRACT FROM AUTHOR]

Published
2024
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8. Energy-dependent photoion angular distributions in two-body Coulomb explosions of molecules.

Author

Guo, Keyu, Li, Yingbin, Li, Min, Cao, Chuanpeng, Duan, Xueqing, Liu, Yang, Liu, Yupeng, Li, Zichen, Xu, Jingkun, Zhou, Yueming, Yu, Benhai, and Lu, Peixiang

Abstract

We experimentally study two-body Coulomb explosions of CO2, O2, and CH3Cl molecules in intense femtosecond laser pulses. We observe an obvious variation in the ionic angular distribution of the fragments with respect to the kinetic energy releases (KERs). Using a classical model based on ab initio potential energy curves, we find that the dependence of the ionic angular distribution on the KER is relevant to the fact that the accurate potential energy deviates significantly from the value determined by applying the Coulomb interaction approximation at a relatively small internuclear distance of the molecule. We show that the KER-dependent ionic angular distribution provides an effective way to determine the critical internuclear distance at which the Coulomb interaction approximation holds or breaks down without relying on the knowledge of the accurate potential energy curves. [ABSTRACT FROM AUTHOR]

Published
2024
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10. Intelligent Feeding Algorithm for Recirculating Aquaculture System Based on Deep Learning

Author

Yang, Jinhui, Wu, Haofeng, Yang, Junchao, Zhou, Yueming, Shen, Yu, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, S. Shmaliy, Yuriy, editor, and Abdelnaby Zekry, Abdelhalim, editor

Published
2022
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17. The optimized field amplitude ratio for nonsequential double ionization by counter-rotating two-color circularly polarized fields.

Author

Wang, Qian, Xu, Jingkun, Cao, Chuanpeng, Liang, Jintai, Li, Min, Liu, Kunlong, Huang, Cheng, and Zhou, Yueming

Subjects
ECONOMIES of scale
Abstract

With a classical trajectory Monte Carlo model, we systematically study the laser intensity and field amplitude ratio dependence of nonsequential double ionization by counter-rotating two-color circularly polarized fields (800 and 1600 nm). The results show that the optimized field amplitude ratio changes with the laser intensity, which is attributed to the shift of the most probable amplitude ratio of electron returning with the laser intensity. Moreover, the laser intensity-dependent double ionization probability curve shows a remarkable dip in the transition region between the nonsequential and sequential channels. It can be well explained by the reduction of the probability of electron returning with the increase of the laser intensity. [ABSTRACT FROM AUTHOR]

Published
2024
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18. In-line attosecond photoelectron holography for single photon ionization.

Author

Liu, Yanhong, Cao, Wei, Yao, Ling-hui, Pi, Liang-Wen, Zhou, Yueming, and Lu, Peixiang

Abstract

The momentum distribution of photoelectrons in H2+ molecules subjected to an attosecond pulse is theoretically investigated. To better understand the laser–molecule interaction, we develop an in-line photoelectron holography approach that is analogous to optical holography. This approach is specifically suitable for extracting the amplitude and phase of the forward-scattered electron wave packet in a dissociating molecule with atomic precision. We also extend this approach to imaging the transient scattering cross-section of a molecule dressed by a near infrared laser field. This attosecond photoelectron holography sheds light on structural microscopy of dissociating molecules with high spatial-temporal resolution. [ABSTRACT FROM AUTHOR]

Published
2024
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32. ZIM1 Combined with Hydrogel Inhibits Senescence of Primary PαS Cells during In Vitro Expansion

Author

Zhou, Yueming Tian, Menglong Hu, Xuenan Liu, Xu Wang, Dazhuang Lu, Zheng Li, Yunsong Liu, Ping Zhang, and Yongsheng

Subjects
stem cells, cellular senescence, transcriptomics, Wnt pathway, hydrogel
Abstract

Bone marrow stem cells (BMSCs) are a promising source of seed cells in bone tissue engineering, which needs a great quantity of cells. Cell senescence occurs as they are passaged, which could affect the therapeutic effects of cells. Therefore, this study aims to explore the transcriptomic differences among the uncultured and passaged cells, finding a practical target gene for anti-aging. We sorted PαS (PDGFR-α+SCA-1+CD45-TER119-) cells as BMSCs by flow cytometry analysis. The changes in cellular senescence phenotype (Counting Kit-8 (CCK-8) assay, reactive oxygen species (ROS) test, senescence-associated β-galactosidase (SA-β-Gal) activity staining, expression of aging-related genes, telomere-related changes and in vivo differentiation potential) and associated transcriptional alterations during three important cell culture processes (in vivo, first adherence in vitro, first passage, and serial passage in vitro) were studied. Overexpression plasmids of potential target genes were made and examed. Gelatin methacryloyl (GelMA) was applied to explore the anti-aging effects combined with the target gene. Aging-related genes and ROS levels increased, telomerase activity and average telomere length decreased, and SA-β-Gal activities increased as cells were passaged. RNA-seq offered that imprinted zinc-finger gene 1 (Zim1) played a critical role in anti-aging during cell culture. Further, Zim1 combined with GelMA reduced the expression of P16/P53 and ROS levels with doubled telomerase activities. Few SA-β-Gal positive cells were found in the above state. These effects are achieved at least by the activation of Wnt/β-catenin signaling through the regulation of Wnt2. The combined application of Zim1 and hydrogel could inhibit the senescence of BMSCs during in vitro expansion, which may benefit clinical application.

Published
2023
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