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974 results on '"Li, Shifeng"'

1. High-accuracy numerical methods and convergence analysis for Schr\'odinger equation with incommensurate potentials

Author

Jiang, Kai, Li, Shifeng, and Zhang, Juan

Subjects
Mathematics - Numerical Analysis
Abstract

Numerical solving the Schr\"odinger equation with incommensurate potentials presents a great challenge since its solutions could be space-filling quasiperiodic structures without translational symmetry nor decay. In this paper, we propose two high-accuracy numerical methods to solve the time-dependent quasiperiodic Schr\"odinger equation. Concretely, we discretize the spatial variables by the quasiperiodic spectral method and the projection method, and the time variable by the second-order operator splitting method. The corresponding convergence analysis is also presented and shows that the proposed methods both have exponential convergence rate in space and second order accuracy in time, respectively. Meanwhile, we analyse the computational complexity of these numerical algorithms. One- and two-dimensional numerical results verify these convergence conclusions, and demonstrate that the projection method is more efficient.

Published
2023

2. On the approximation of quasiperiodic functions with Diophantine frequencies by periodic functions

Author

Jiang, Kai, Li, Shifeng, and Zhang, Pingwen

Subjects
Mathematics - Number Theory
Abstract

We present an analysis of the approximation error for a $d$-dimensional quasiperiodic function $f$ with Diophantine frequencies, approximated by a periodic function with period $[0,L)^d$. When $f$ has a certain regularity, its global behavior can be described by a finite number of Fourier components and has a polynomial decay at infinity. The dominant part of periodic approximation error is bounded by $O(L^{-1/s})$, where $L$ belongs to the best simultaneous approximation sequence of Fourier frequencies and $s$ is the number of different irrational elements in Fourier frequencies. Meanwhile, we discuss the optimal approximation rate. Finally, these analytical results are verified by some examples.

Published
2023

3. Crack Analysis and Improvement of Helicopter Engine Compartment Partition

Author

Yin, Zhongwei, Li, Shifeng, Cao, Jinhua, Lin, Changliang, Zhang, He, Chinese Society of Aeronautics and Astronautics, Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Ivanov, Vitalii, Series Editor, Haddar, Mohamed, Series Editor, Cavas-Martínez, Francisco, Editorial Board Member, di Mare, Francesca, Editorial Board Member, Kwon, Young W., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, and Xu, Jinyang, Editorial Board Member

Published
2024
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7. Numerical Methods and Analysis of Computing Quasiperiodic Systems

Author

Jiang, Kai, Li, ShiFeng, and Zhang, Pingwen

Subjects
Mathematics - Numerical Analysis
Abstract

Quasiperiodic systems are important space-filling ordered structures, without decay and translational invariance. How to solve quasiperiodic systems accurately and efficiently is of great challenge. A useful approach, the projection method (PM) [J. Comput. Phys., 256: 428, 2014], has been proposed to compute quasiperiodic systems. Various studies have demonstrated that the PM is an accurate and efficient method to solve quasiperiodic systems. However, there is a lack of theoretical analysis of PM. In this paper, we present a rigorous convergence analysis of the PM by establishing a mathematical framework of quasiperiodic functions and their high-dimensional periodic functions. We also give a theoretical analysis of quasiperiodic spectral method (QSM) based on this framework. Results demonstrate that PM and QSM both have exponential decay, and the QSM (PM) is a generalization of the periodic Fourier spectral (pseudo-spectral) method. Then we analyze the computational complexity of PM and QSM in calculating quasiperiodic systems. The PM can use fast Fourier transform, while the QSM cannot. Moreover, we investigate the accuracy and efficiency of PM, QSM and periodic approximation method in solving the linear time-dependent quasiperiodic Schr\"{o}dinger equation.

Published
2022

9. A general alternating-direction implicit Newton method for solving complex continuous-time algebraic Riccati matrix equation

Author

Li, Shifeng and Zhang, Kai Jiang Juan

Subjects
Mathematics - Numerical Analysis
Abstract

In this paper, applying the Newton method, we transform the complex continuous-time algebraic Riccati matrix equation into a Lyapunov equation. Then, we introduce an efficient general alternating-direction implicit (GADI) method to solve the Lyapunov equation. The inexact Newton-GADI method is presented to save computational amount effectively. Moreover, we analyze the convergence of the Newton-GADI method. The convergence rate of the Newton-GADI and Newton-ADI methods is compared by analyzing their spectral radii. Furthermore, we give a way to select the quasi-optimal parameter. Corresponding numerical tests are shown to illustrate the effectiveness of the proposed algorithms.

Published
2022

14. Carbon and oxygen isotope characteristics of carbonate rocks in the Mesoproterozoic Jixian System of the Ordos Basin and their implications

Author

Liu Xiaofeng, Hong Zenglin, Liang Jiwei, Guo Xiaodan, Xue Xuping, and Li Shifeng

Subjects
Medicine, Science
Abstract

Abstract The paleoenvironment of Jixian carbonate rocks in the Mesoproterozoic Ordos Basin is studied by carbon and oxygen isotope analyses, diagenetic environment analysis, and the restoration of paleosalinity and paleotemperature. The results indicate that the carbonate rocks of the Jixian System have always been in a near-surface environment and have not been deeply buried. The ranges of variation in δ13CPDB and δ18OPDB are relatively narrow, ranging from − 5.75 to 1.41‰ and − 8.88 to − 4.01‰, respectively, which is consistent with the stable tidal flat sedimentary environment during the Mesoproterozoic in the study area. The paleosalinity (Z) values range from 111.7 to 127.1, and the paleotemperature (T) values range from 32.7 to 57.33 °C, indicating a relatively warm paleoclimatic environment during the Mesoproterozoic era in the study area. The analysis shows that in a warm paleoclimatic environment, although carbon and oxygen isotopes, Z, and T have certain fluctuations, their ranges are relatively small, reflecting to some extent the stable tectonic environment of the study area during the Mesoproterozoic era. Comprehensive research shows that the Ordos Basin had a warm climate and a stable tectonic environment in the Mesoproterozoic, which may be a good response to the North China Block's position near the equator and continuous thermal subsidence in the Mesoproterozoic.

Published
2023
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19. Self-affirmation increases acceptance of information on COVID-19 vaccines and promotes vaccination intention

Author

Li, Shifeng, Xia, Yingchun, Zhao, Wei, Miao, Xiaohui, and Xu, Qiongying

Subjects
Self-affirmation (Psychology) -- Influence, Health behavior -- Analysis, Psychology and mental health
Abstract

Previous studies have shown that self-affirmation increases acceptance of a message and motivates health behavior change. The present study investigated whether self-affirmation increases the acceptance of persuasive messages on COVID-19 vaccines and promotes vaccination intention. A total of 144 participants were randomly assigned to the self-affirmation (n = 72) or control (n = 72) groups before reading a persuasive message on COVID-19 vaccines. The results revealed that the self-affirmation group showed significantly higher acceptance of persuasive information on COVID-19 vaccines than the control group. Additionally, the self-affirmation group also showed significantly higher post-experiment vaccination intention than the control group. Mediation analysis indicated that increased acceptance of persuasive information significantly mediated the beneficial effects of self-affirmation on post-experiment vaccination intention. The present study demonstrated that self-affirmation could be an effective strategy for increasing the acceptance of persuasive messages on COVID-19 vaccines and promoting vaccination intention., Author(s): Shifeng Li [sup.1] [sup.2] , Yingchun Xia [sup.1] [sup.2] , Wei Zhao [sup.1] [sup.2] , Xiaohui Miao [sup.1] [sup.2] , Qiongying Xu [sup.1] [sup.2] Author Affiliations: (1) grid.412260.3, 0000 [...]

Published
2023
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20. A Double Res-UNET with Attention Mechanism for Change Detection of Remote Sensing Images

Author

Li, Shifeng, Pan, Dongbo, Yuan, Jianjun, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, 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, 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, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Panigrahi, Bijaya Ketan, 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, Tan, Kay Chen, Series Editor, Qian, Zhihong, editor, Jabbar, M.A., editor, Cheung, Simon K. S., editor, and Li, Xiaolong, editor

Published
2023
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21. Impact Energy Absorption Features for Tensor-Skin Fuselage Box Structure

Author

Han, Liu, Qi, Hui, Li, Shifeng, Men, Kunfa, Wang, Jinliang, 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, and Chinese Society of Aeronautics and Astronautics, editor

Published
2023
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22. Bending Properties of Representative Composite Aircraft Structures Under Oil Pressure

Author

Han, Liu, Qi, Hui, Li, Shifeng, Zhang, Zhen, Gong, Shaobo, 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, and Chinese Society of Aeronautics and Astronautics, editor

Published
2023
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25. Numerical methods for the mass-conserved Ohta-Kawasaki equation

Author

Zhang, Juan, Li, Shifeng, and Jiang, Kai

Subjects
Mathematics - Numerical Analysis
Abstract

In this paper, we propose a numerical method to solve the mass-conserved Ohta-Kawasaki equation with finite element discretization. An unconditional stable convex split-ting scheme is applied to time approximation. The Newton method and its variant are used to address the implicitly nonlinear term. We rigorously analyze the convergence of the Newton iteration methods. Theoretical results demonstrate that two Newton iteration methods have the same convergence rate, and the Newton method has a smaller convergent factor than the variant one. To reduce the condition number of discretized linear system, we design two efficient block preconditioners and analyze their spectral distribution. Finally, we offer numerical examples to support the theoretical analysis and indicate the efficiency of the proposed numerical methods for the mass-conserved Ohta-Kawasaki equation., Comment: 28 pages, 9 figures

Published
2019

31. High-efficiency nonlinear frequency conversion enabled by optimizing the ferroelectric domain structure in x-cut LNOI ridge waveguide

Author

Su, Yawen, primary, Zhang, Xinyu, additional, Chen, Haiwei, additional, Li, Shifeng, additional, Ma, Jianan, additional, Li, Wei, additional, Niu, Yunfei, additional, Qin, Qi, additional, Yang, Shaoguang, additional, Deng, Yu, additional, Zhang, Yong, additional, Hu, Xiaopeng, additional, and Zhu, Shining, additional

Published
2024
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37. Research on Typical Joint Technology of Composite Stiffened Skin-Fuselage Frame

Author

Han, Liu, Qi, Hui, Li, Rui, Liu, Pingan, Li, Shifeng, Zhan, Zhen, Wang, Jinliang, Chinese Society of Aeronautics and Astronautics, 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, 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, and Zhang, Junjie James, Series Editor

Published
2022
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38. Targeting PARP11 to avert immunosuppression and improve CAR T therapy in solid tumors

Author

Zhang, Hongru, Yu, Pengfei, Tomar, Vivek S., Chen, Xiangjie, Atherton, Matthew J., Lu, Zhen, Zhang, Hong-Guang, Li, Shifeng, Ortiz, Angelica, Gui, Jun, Leu, N. Adrian, Yan, Fangxue, Blanco, Andres, Meyer-Ficca, Mirella L., Meyer, Ralph G., Beiting, Daniel P., Li, Jinyang, Nunez-Cruz, Selene, O’Connor, Roddy S., Johnson, Lexus R., Minn, Andy J., George, Subin S., Koumenis, Constantinos, Diehl, J. Alan, Milone, Michael C., Zheng, Hui, and Fuchs, Serge Y.

Published
2022
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40. Who Are the Nonresponders to Intervention among Chinese Children Learning English as a Second Language?

Author

Xu, Qinfang, Tao, Sha, Li, Shifeng, Wang, Wenjing, Li, Beilei, and Joshi, R. Malatesha

Abstract

The purpose of this study was to examine the profiles of nonresponders among native Chinese-speaking students struggling in English reading before and after an intensive intervention in phonological awareness as well as letter knowledge. Struggling English learners (n = 72) were screened from 668 Grade 4 students based on their English word recognition, school English examinations, and nominations by teachers. About 43% of struggling readers were remediated in decoding skills after the intervention. Nonresponders were profiled on both phonological and orthographic processing skills in their first and second languages. More than 76% of nonresponders showed deficits in English rapid letter naming, letter sound knowledge and English orthographic image. Nonresponders also had deficits in Chinese phonological memory and rapid digit naming. Rapid letter naming made the most contribution to word reading after intervention and letter sound knowledge was the only significant predictor in 1-year follow-up word reading. The findings suggest that Chinese poor English learners have difficulties in both phonological and orthographic processing in English reading. Educational implications are discussed using the triangle model.

Published
2021
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49. Perceived Quality of Parent-Child Relationships by Chinese Primary School Students: The Role of Parents' Education and Parent-Child Literacy Activities

Author

Li, Shifeng, Nan, Nan, Xu, Qiongying, and Li, Jiayue

Abstract

Previous studies have revealed that the perceived quality of the parent-child relationship is essential for both physical health and psychological well-being. However, most studies have treated the perceived quality of this relationship as an independent variable. In this study, we considered it a dependent variable and examined the role of parents' education and parent-child literacy activities on children's perceived quality of the parent-child relationship. One hundred and eighty-six Chinese primary school students and their parents from low socioeconomic backgrounds participated in this study. Parents' educational level and the parent-child literacy activity status were assessed based on parents' reports, whereas parent-child relationships were assessed based on children's reports. Results showed that parents' educational level positively correlated with the frequency of parent-child literacy activities and children's perceptions of the quality of the parent-child relationship. There was also a significant positive correlation between the frequency of parent-child literacy activities and children's perceptions of the quality of the parent-child relationship. Further analyses showed that the frequency of parent-child literacy activities mediated the connection between parents' educational level and children's perceived quality of the parent-child relationship. These results suggest that boosting the frequency of parent-child literacy activities may be a useful strategy for facilitating the parent-child relationship.

Published
2020
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