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Your search keyword '"Zhang, Xixi"' showing total 352 results
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352 results on '"Zhang, Xixi"'

2. High-performance magnesium/sodium hybrid ion battery based on sodium vanadate oxide for reversible storage of Na+ and Mg2+

Author

Wang, Xiaoke, Li, Titi, Zhang, Xixi, Wang, Yaxin, Li, Hongfei, Li, Hai-Feng, Zhao, Gang, and Han, Cuiping

Subjects
Condensed Matter - Materials Science, Physics - Chemical Physics
Abstract

Magnesium ion batteries (MIBs) are a potential field for the energy storage of the future but are restricted by insufficient rate capability and rapid capacity degradation. Magnesium-sodium hybrid ion batteries (MSHBs) are an effective way to address these problems. Here, we report a new type of MSHBs that use layered sodium vanadate ((Na, Mn)V8O20 5H2O, Mn-NVO) cathodes coupled with an organic 3,4,9,10-perylenetetracarboxylic diimide (PTCDI) anode in Mg2+/Na+ hybrid electrolytes. During electrochemical cycling, Mg2+ and Na+ co-participate in the cathode reactions, and the introduction of Na+ promotes the structural stability of the Mn-NVO cathode, as cleared by several ex-situ characterizations. Consequently, the Mn-NVO cathode presents great specific capacity (249.9 mAh g-1 at 300 mA g-1) and cycling (1500 cycles at 1500 mA g-1) in the Mg2+/Na+ hybrid electrolytes. Besides, full battery displays long lifespan with 10,000 cycles at 1000 mA g-1. The rate performance and cycling stability of MSHBs have been improved by an economical and scalable method, and the mechanism for these improvements was discussed.

Published
2024
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3. Virtual Student Mobility from Students' Perspectives: Case Study from Japan

Author

Enkhtur, Ariunaa, Li, Ming, and Zhang, Xixi

Abstract

International student exchange is integral to internationalization at higher education institutions and global human resource development in Japan. However, border closures and restrictions on physical mobility since 2020 due to the COVID-19 pandemic forced universities to adopt virtual mobility models to deliver international exchange programs. This study explores students' experiences of taking virtual exchange programs and their pedagogical implications for future virtual exchange programs. In this paper, we present one case of virtual student mobility implemented at one national university in Japan. Analysis of multiple data sets, including student surveys (n=789), reflection papers (n=420), and interviews with a program administrator and a faculty member, revealed that this type of virtual student mobility program has strong merits in promoting internationalization activities. Students were satisfied with the diverse interdisciplinary academic content, flexibility in taking the course, and opportunity to engage with the host university faculty members and international students. Many have expressed their interest in studying at the host university in person.

Published
2023

7. A Real-World Radio Frequency Signal Dataset Based on LTE System and Variable Channels

Author

Zhang, Shupeng, Zhang, Yibin, Zhang, Xixi, Sun, Jinlong, Lin, Yun, Gacanin, Haris, Adachi, Fumiyuki, and Gui, Guan

Subjects
Electrical Engineering and Systems Science - Signal Processing
Abstract

Radio Frequency Fingerprint (RFF) identification on account of deep learning has the potential to enhance the security performance of wireless networks. Recently, several RFF datasets were proposed to satisfy requirements of large-scale datasets. However, most of these datasets are collected from 2.4G WiFi devices and through similar channel environments. Meanwhile, they only provided receiving data collected by the specific equipment. This paper utilizes software radio peripheral as a dataset generating platform. Therefore, the user can customize the parameters of the dataset, such as frequency band, modulation mode, antenna gain, and so on. In addition, the proposed dataset is generated through various and complex channel environments, which aims to better characterize the radio frequency signals in the real world. We collect the dataset at transmitters and receivers to simulate a real-world RFF dataset based on the long-term evolution (LTE). Furthermore, we verify the dataset and confirm its reliability. The dataset and reproducible code of this paper can be downloaded from GitHub link: https://github.com/njuptzsp/XSRPdataset.

Published
2022

36. Vascular cambium stem cells: past, present and future.

Author

Wybouw, Brecht, Zhang, Xixi, and Mähönen, Ari Pekka

Subjects
*STEM cells, *CAMBIUM, *CELL physiology, *SIGNAL peptides, *MERISTEMS
Abstract

Summary: Secondary xylem and phloem originate from a lateral meristem called the vascular cambium that consists of one to several layers of meristematic cells. Recent lineage tracing studies have shown that only one of the cambial cells in each radial cell file functions as the stem cell, capable of producing both secondary xylem and phloem. Here, we first review how phytohormones and signalling peptides regulate vascular cambium formation and activity. We then propose how the stem cell concept, familiar from apical meristems, could be applied to cambium studies. Finally, we discuss how this concept could set the basis for future research. [ABSTRACT FROM AUTHOR]

Published
2024
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50. Activating and Stabilizing a Reversible four Electron Redox Reaction of I−/I+ for Aqueous Zn‐Iodine Battery.

Author

Wang, Chenggang, Ji, Xiaoxing, Liang, Jianing, Zhao, Shunshun, Zhang, Xixi, Qu, Guangmeng, Shao, Wenfeng, Li, Chuanlin, Zhao, Gang, Xu, Xijin, and Li, Huiqiao

Subjects
OXIDATION-reduction reaction, ELECTRONS, STORAGE batteries, ELECTRIC batteries
Abstract

Low capacity and poor cycle stability greatly inhibit the development of zinc‐iodine batteries. Herein, a high‐performance Zn‐iodine battery has been reached by designing and optimizing both electrode and electrolyte. The Br− is introduced as the activator to trigger I+, and coupled with I+ forming interhalogen to stabilize I+ to achieve a four‐electron reaction, which greatly promotes the capacity. And the Ni−Fe−I LDH nanoflowers serve as the confinement host to enable the reactions of I−/I+ occurring in the layer due to the spacious and stable interlayer spacing of Ni−Fe−I LDH, which effectively suppresses the iodine‐species shuttle ensuring high cycling stability. As a result, the electrochemical performance is greatly enhanced, especially in specific capacity (as high as 350 mAh g−1 at 1 A g−1 far higher than two‐electron transfer Zn‐iodine batteries) and cycling performance (94.6 % capacity retention after 10000 cycles). This strategy provides a new way to realize high capacity and long‐term stability of Zn‐iodine batteries. [ABSTRACT FROM AUTHOR]

Published
2024
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