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Your search keyword '"Zhang, Zikai"' showing total 120 results
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120 results on '"Zhang, Zikai"'

101. Autologous decellularized extracellular matrix promotes adipogenic differentiation of adipose derived stem cells in low serum culture system by regulating the ERK1/2-PPARγ pathway

Author

Qian, Yao, primary, Chen, Hao, additional, Pan, Tianyun, additional, Li, Tian, additional, Zhang, Zikai, additional, Lv, Xuling, additional, Wang, Jingping, additional, Ji, Ziwan, additional, He, Yucang, additional, Li, Liqun, additional, and Lin, Ming, additional

Published
2021
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116. Segmented compressed sensing scheme for uwb channel estimation

Author

Deqiang Wang, Li Guozhu, Li Zhiyong, and Zhang Zikai

Subjects
Compressed sensing, Matching (graph theory), Electronic engineering, Waveform, Scale (descriptive set theory), Realization (systems), Matching pursuit, Signal, Computer Science::Information Theory, Communication channel, Mathematics
Abstract

Due to the high bandwidth of ultra-wideband (UWB) signals, channel estimation is regarded as a challenging issue involved in the realization of digital UWB receivers. Fortunately, the compressed sensing (CS) theory provides a promising way to solve this problem with much lower sampling rate. In traditional CS-based channel estimation schemes, researchers estimate the whole channel waveform at a time. Usually, the implementation complexity is nontrivial. In this paper, we propose a segmented CS-based channel estimation scheme. Specifically, the channel waveform is estimated in a segment by segment manner. For each segment, both the sparsity of the signal and the required scale of the measurement matrix are relatively lower. As a result, the implementation complexity can be reduced effectively. In order to improve the channel estimation performance in noisy environments, making use of the prior information on the UWB signals, we propose a weighted orthogonal matching pursuit (WOMP) algorithm. In WOMP, a weighted matching progress is performed such that dominating components of the target signal can be recovered more reliably. Simulation results show that good performance can be achieved by using our proposed scheme.

Published
2014

117. On the Engendering of Chinese Analects.

Author

Zhang Zikai

Abstract

Up to now, there is also blind spots and mistaken ideas about the forming of analects, and confuse about their difference. In fact, three analects sprang from unlike culture. During the last stage of Spring and Autumn Period, as education spread and affected by the concept of expounding on predecessors' theories without producing anything original itself, Confucius's disciples recorded teaching content as The Analects of Confucius: The Chan school in the Early Tang followed the teaching method of Indian Buddhism, and regarded language as skillful means, which emulated samgiti and Sutra to sum up master's speech. Inspired by monks, scholars of Neo-Confucianism in Song Dynasty explained theories in college and took notes imitating The Analects of Confucius. In a word, analects ars the results of either developing separately or reflecting each other of the culture of China and India, which shows the different ideas of language. [ABSTRACT FROM AUTHOR]

Published
2009

118. Are residents more willing to buy and pay for electric vehicles under the “carbon neutrality”?

Author

Zhang, Zikai, Sheng, Ni, Zhao, Daiqing, Cai, Kaihan, Yang, Guiming, and Song, Qingbin

Abstract

The transportation sector will be critical to the successful pursuit of the carbon neutrality goal in China. Electric vehicles (EVs) have seemed to be an important solution, for reducing carbon emissions, and residents’ support will be essential to achieve the extensive use of EVs. Thus, this study aimed to explore Macao residents’ willingness to buy (WTB) and pay for (WTP) EVs through 406 questionnaires, and to determine the influencing factors. The results showed that convenience, actual cost and environmental benefits are the consideration factors for residents to purchase EVs. It was found that 90.14% of respondents were willing to buy an EV. For WTP, however, the proportion fell to 56.71%. The environmental benefits, battery range, charging convenience and safety of EVs, and consumer income are all positively correlated with respondents’ WTB. For their WTP, potential pollution from fuel vehicles, driving frequency and environmental benefits of EVs were more important. Using the contingent valuation method (CVM), it was estimated that respondents’ WTP value is about 15041.10 MOP (much lower than market value gap: 50000 MOP). In summary, the existing policies in Macao are insufficient to guide and improve the residents’ WTB and WTP. In the future, the government should strengthen publicity, especially to young consumers, and give EV owners some privileges, to stimulate residents’ WTB and WTP. In addition, in the context of carbon neutrality, more attention should be paid to cleaner power generation in Macao.

Published
2022
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119. Research on the causal mechanism of a rock burst accident in a longwall roadway and its prevention measures.

Author

Chen Y, Zhang Z, Cao C, Bao S, Wang S, and Xu G

Abstract

Based on the disaster characteristics and the geo-conditions at the scene, in this study, the occurrence mechanism of a serious rock burst accident that occurred in the Tangshan Coal Mine, China, was analysed. Ground stress measurements showed that the mine is in a high ground stress area dominated by horizontal tectonic stress around 33 MPa. Laboratory testing revealed that the coal was a hard seam of 8.3 MPa over bedded by a thick and hard roof stratum with uniaxial compressive strength of 66 MPa. The calculation results indicated that the accident occurred in the roof rebounding area. It is proposed that the hard roof and the hard coal seam formed a seesaw structure around the working face. The vertical pressure relief caused the rib coal mass to lose its clamping forces from the roof and floor and rush into the roadway, resulting in a rock burst accident. Based on the causality mechanism of the rock burst disaster developed in this study, pertinent coal bump prevention measures have been undertaken in practice. Large-diameter boreholes were drilled to eliminate the pivot effect of the seam. Roof blasting was undertaken to prevent the roof from forming a seesaw plank. To summarize, a new causality mechanism for rock burst in coal mines under hard roof and hard seam geo-conditions was developed., (© 2023. The Author(s).)

Published
2023
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