5 results on '"Liu, Yifeng"'
Search Results
2. The dual built-in electric fields across CoS/MoS2 heterojunctions for energy-saving hydrogen production coupled with sulfion degradation.
- Author
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Gao, Kaiwen, Zhou, Min, Liu, Yifeng, Wang, Shuocheng, Fu, Rong, Wang, Zhaoyang, Guo, Jinghui, Liu, Ziang, Wang, Hairen, Zhao, Yan, and Wang, Qijun
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HYDROGEN evolution reactions , *ELECTRIC fields , *HYDROGEN production , *POLLUTANTS , *OXYGEN evolution reactions , *SULFURATION , *DESULFURIZATION - Abstract
A core/shell CoS/MoS 2 microflower with CoS/MoS 2 /CoS dual-heterojunctions, resembling a "ball of yarn," is successfully fabricated using a structure-breaking sulfuration strategy. The unique catalyst design of this system showcases dual built-in electric fields at the hierarchical interfaces, effectively enhancing the adsorption behavior of catalytic intermediates and reducing energy barriers in catalytic reactions for cost-effective hydrogen production and environmentally-friendly sulfion recycling. [Display omitted] • A "ball of yarn" microflower with CoS/MoS 2 /CoS dual-heterojunctions is fabricated via a structure-breaking sulfuration strategy. • The work function difference between CoS and MoS 2 induces electron polarization, creating dual built-in electric fields at interfaces. • The electrocatalytic coupling system only needs a cell voltage of 0.528 V at 10 mA/cm², maintaining long-term durability for over 168 hours. • DFT calculations confirm that CoS/MoS 2 interfaces enhance electron transfer, optimize catalytic adsorption, and lower energy barriers. Substituting the sluggish oxygen evolution reaction with the sulfur oxidation reaction can significantly reduce energy consumption and eliminate environmental pollutants during hydrogen generation. However, the progress of this technology has been hindered due to the lack of cost-effective, efficient, and durable electrocatalysts. In this study, we present the design and construction of a hierarchical metal sulfide catalyst with a gradient structure comprising nanoparticles, nanosheets, and microparticles. This was achieved through a structure-breaking sulfuration strategy, resulting in a "ball of yarn"-like core/shell CoS/MoS 2 microflower with CoS/MoS 2 /CoS dual-heterojunctions. The difference in work functions between CoS and MoS 2 induces an electron polarization effect, creating dual built-in electric fields at the hierarchical interfaces. This effectively modulates the adsorption behavior of catalytic intermediates, thereby reducing the energy barrier for catalytic reactions. The optimized catalyst exhibits outstanding electrocatalytic performance for both the hydrogen evolution reaction and the sulfur oxidation reaction. Remarkably, in the assembled electrocatalytic coupling system, it only requires a cell voltage of 0.528 V at 10 mA cm−2 and maintains long-term durability for over 168 h. This work presents new opportunities for low-cost hydrogen production and environmentally friendly sulfion recycling. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. Segmentation by weighted aggregation and perceptual hash for pedestrian detection.
- Author
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Liu, Yifeng, Zou, Lian, Li, Jie, Yan, Jia, Shi, Wenxuan, and Deng, Dexiang
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IMAGE segmentation , *AGGREGATION (Statistics) , *PEDESTRIANS , *PROBABILITY measures , *TRAFFIC monitoring , *IMAGE retrieval - Abstract
Main challenges of pedestrian detection are caused by the intra-class variation of pedestrians in clothing, scales, deformations, occlusions, and backgrounds. The prevalent detection frameworks employ a series of dense sliding windows, which are time-consuming. In this work, we equip the detection framework with another new strategy, and extract the new features, to eliminate the above requirements. Segmentation by weighted aggregation (SWA) provides a probability measure to segment objects from complex backgrounds. Perceptual hash (pHash) has shown its power in similar image retrieval because it is modification-tolerant and scale-invariant. The proposed approach uses binarized normed gradients (BING) to efficiently generate a small set of estimation proposals, and formulates SWA and pHash into a joint descriptor, called HASP, to improve the detection performance significantly. Experimental results both on INRIA dataset and ETH dataset have demonstrated the effectiveness and efficiency of the proposed approach. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
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4. Uniqueness of Fourier–Jacobi models: The Archimedean case.
- Author
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Liu, Yifeng and Sun, Binyong
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UNIQUENESS (Mathematics) , *JACOBI method , *ARCHIMEDEAN property , *UNITARY groups , *SYMPLECTIC groups , *FOURIER series - Abstract
Abstract: We prove uniqueness of Fourier–Jacobi models for general linear groups, unitary groups, symplectic groups and metaplectic groups, over an Archimedean local field. [Copyright &y& Elsevier]
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- 2013
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5. The effects and mechanisms of GM-CSF on endometrial regeneration.
- Author
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Liu, Juan, Ying, Yanyun, Wang, Siwen, Li, Jingyi, Xu, Jinqun, Lv, Pingping, Chen, Jianhua, Zhou, Caiyun, Liu, Yifeng, Wu, Yiqing, Huang, Yun, Chen, Yao, Chen, Lifen, Tu, Shijiong, Zhao, Wei, Yang, Min, Hu, Yanjun, Zhang, Runju, and Zhang, Dan
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GRANULOCYTE-macrophage colony-stimulating factor , *STROMAL cells , *CELL migration , *CEREBROSPINAL fluid examination , *ENDOMETRIUM - Abstract
• GM-CSF improves regeneration of injured endometrium in mice. • GM-CSF increases the proliferation of primary human endometrial glandular cell and the migration of stromal cell. • GM-CSF has potential application in clinical treatment for thin endometrium. Endometrial injury can result in thin endometrium and subfertility. Granulocyte macrophage colony stimulating factor (GM-CSF) contributes to tissue repair, but its role in endometrial regeneration has not been investigated. To determine the effect of GM-CSF on endometrial regeneration, we established a mouse model of thin endometrium by uterine perfusion with 20 μL 90% ethanol. Thin endometrium in mice was featured by lowered endometrial thickness, decreased expression of Ki67 in glandular cells, and a reduced number of implantation sites. To explore the mechanism of GM-CSF on endometrial regeneration, endometrium was obtained from patients undergoing hysterectomy or hysteroscopy and endometrial biopsy. Effects of GM-CSF on primary cultured human endometrial glandular and stromal cells were examined by the 5-bromo-2′-deoxyuridine (BrdU) proliferation assay and transwell migration assay, followed by exploration of the potential signaling pathway. GM-CSF intraperitoneal (i.p.) injection significantly increased endometrial thickness, expression of Ki67 in endometrial glandular cells, and the number of implantation sites. GM-CSF significantly promoted proliferation of primary human endometrial glandular cells and migration of stromal cells. GM-CSF activated p-Akt and increased expressions of p70S6K and c-Jun, which were blocked by LY294002. We found that GM-CSF could improve endometrial regeneration, possibly through activating PI3K/Akt signaling pathway. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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