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Your search keyword '"Zhang, Xin-fang"' showing total 198 results
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198 results on '"Zhang, Xin-fang"'

1. QQMR: A Structure-Preserving Quaternion Quasi-Minimal Residual Method for Non-Hermitian Quaternion Linear Systems

Author

Li, Tao, Wang, Qing-Wen, and Zhang, Xin-Fang

Subjects
Mathematics - Numerical Analysis, 15B33, 65F08, 65F10, 94A08
Abstract

The quaternion biconjugate gradient (QBiCG) method, as a novel variant of quaternion Lanczos-type methods for solving the non-Hermitian quaternion linear systems, does not yield a minimization property. This means that the method possesses a rather irregular convergence behavior, which leads to numerical instability. In this paper, we propose a new structure-preserving quaternion quasi-minimal residual method, based on the quaternion biconjugate orthonormalization procedure with coupled two-term recurrences, which overcomes the drawback of QBiCG. The computational cost and storage required by the proposed method are much less than the traditional QMR iterations for the real representation of quaternion linear systems. Some convergence properties of which are also established. Finally, we report the numerical results to show the robustness and effectiveness of the proposed method compared with QBiCG., Comment: 25 pages

Published
2024

4. Gl-QFOM and Gl-QGMRES: two efficient algorithms for quaternion linear systems with multiple right-hand sides

Author

Li, Tao, Wang, Qing-Wen, and Zhang, Xin-Fang

Subjects
Mathematics - Numerical Analysis
Abstract

In this paper, we propose the global quaternion full orthogonalization (Gl-QFOM) and global quaternion generalized minimum residual (Gl-QGMRES) methods, which are built upon global orthogonal and oblique projections onto a quaternion matrix Krylov subspace, for solving quaternion linear systems with multiple right-hand sides. We first develop the global quaternion Arnoldi procedure to preserve the quaternion Hessenberg form during the iterations. We then establish the convergence analysis of the proposed methods, and show how to apply them to solve the Sylvester quaternion matrix equation. Numerical examples are provided to illustrate the effectiveness of our methods compared with the traditional Gl-FOM and Gl-GMRES iterations for the real representations of the original linear systems., Comment: 24pages, 4 figures

Published
2023

8. A first-in-human phase 1 study of simnotrelvir, a 3CL-like protease inhibitor for treatment of COVID-19, in healthy adult subjects

Author

Yang, Xin-Mei, Yang, Yang, Yao, Bu-Fan, Ye, Pan-Pan, Xu, Yan, Peng, Shao-Ping, Yang, Yu-Mei, Shu, Pan, Li, Pei-Jin, Li, Shan, Hu, Hong-Lin, Li, Qian, Song, Lin-Lin, Chen, Ke-Guang, Zhou, Hai-Yan, Zhang, Ye-Hui, Zhao, Fu-Rong, Tang, Bo-Hao, Zhang, Wei, Zhang, Xin-Fang, Fu, Shu-Meng, Hao, Guo-Xiang, Zheng, Yi, Shen, Jing-Shan, Xu, Ye-Chun, Jiang, Xiang-Rui, Zhang, Lei-Ke, Tang, Ren-Hong, and Zhao, Wei

Published
2023
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9. Experimental review on Majorana zero-modes in hybrid nanowires

Author

Fu, Ji-Bang, Li, Bin, Zhang, Xin-Fang, Yu, Guang-Zheng, Huang, Guang-Yao, and Deng, Ming-Tang

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Applied Physics
Abstract

As the condensed matter analog of Majorana fermion, the Majorana zero-mode is well known as a building block of fault-tolerant topological quantum computing. This review focuses on the recent progress of Majorana experiments, especially experiments about semiconductor-superconductor hybrid devices. We first sketch Majorana zero-mode formation from a bottom-up view, which is more suitable for beginners and experimentalists. Then, we survey the status of zero-energy state signatures reported recently, from zero-energy conductance peaks, the oscillations, the quantization, and the interactions with extra degrees of freedom. We also give prospects of future experiments for advancing one-dimensional semiconductor nanowire-superconductor hybrid materials and devices., Comment: 16 pages, 9 figures

Published
2020
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16. Iterative solutions of generalized Sylvester quaternion tensor equations.

Author

Zhang, Xin-Fang, Li, Tao, and Ou, Yi-Gui

Subjects
*QUATERNIONS, *KRONECKER products, *EQUATIONS
Abstract

This paper is concerned with the iterative solutions to a class of generalized Sylvester quaternion tensor equations. From the Kronecker product and the properties of quaternion tensors, we propose the biconjugate A-orthogonal residual stabilized and the generalized product-type biconjugate A-orthogonal residual methods in their tensor forms for solving the original tensor equation. As an application, the proposed methods are tested with some colour video restoration problems. Numerical results show the effectiveness of our methods compared with some existing methods. [ABSTRACT FROM AUTHOR]

Published
2024
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29. The Pretreatment of Xiaoqinglong Decoction Alleviates Inflammation and Oxidative Damage and Up-Regulates Angiotensin-Converting Enzyme 2 in Lipopolysaccharide-Induced Septic Acute Lung Injury Rats

Author

Su, Jing-Chao, primary, Cheng, Chen, additional, Wang, Cai-Yun, additional, Zhang, Yi, additional, He, Ya-Ting, additional, Guo, Zi-Wei, additional, Liu, Xin-Yue, additional, Liu, Wen-Mei, additional, Zhang, Yu-Jie, additional, Xu, Shu-Wen, additional, Zhang, Xin-Yue, additional, Liu, Zi-Bing, additional, and Zhang, Xin-Fang, additional

Published
2022
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37. Two new cytotoxic cycloartane triterpenoids from Aphanamixis polystachya (Wall.) R. N. Parker

Author

Wang, Yi-ting, Fan, Shi-rui, Cai, Jie-yun, Guo, Jing-jing, Zhang, Xin-fang, Yang, Bi-juan, Hao, Xiao-jiang, and Chen, Duo-zhi

Abstract

Two new cycloartane triterpenoids, (24 R)-cycloartane-3β,24,25,30-tetrol (1) and (24 R)-24,25,30-trihydroxy-9,19-cycloartane-3-one (2), along with three known compounds (3-5) were isolated from leaves and twigs of Aphanamixis polystachya. The new compounds were elucidated based on comprehensive spectroscopic analysis, including 1 D, 2 D NMR and HREIMS. The in vitro cytotoxic activities evaluation of five human cancer cell lines revealed that compound 1 exhibited cytotoxic activity on all of tested human cancer cell lines, while compound 2 only had specific activity on SMMC-7721 cell line.

Published
2021
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38. Two new cytotoxic cycloartane triterpenoids from Aphanamixis polystachya (Wall.) R. N. Parker.

Author

Wang, Yi-ting, Fan, Shi-rui, Cai, Jie-yun, Guo, Jing-jing, Zhang, Xin-fang, Yang, Bi-juan, Hao, Xiao-jiang, and Chen, Duo-zhi

Subjects
TRITERPENOIDS, CELL lines, CANCER cells, TWIGS
Abstract

Two new cycloartane triterpenoids, (24 R)-cycloartane-3β,24,25,30-tetrol (1) and (24 R)-24,25,30-trihydroxy-9,19-cycloartane-3-one (2), along with three known compounds (3-5) were isolated from leaves and twigs of Aphanamixis polystachya. The new compounds were elucidated based on comprehensive spectroscopic analysis, including 1 D, 2 D NMR and HREIMS. The in vitro cytotoxic activities evaluation of five human cancer cell lines revealed that compound 1 exhibited cytotoxic activity on all of tested human cancer cell lines, while compound 2 only had specific activity on SMMC-7721 cell line. [ABSTRACT FROM AUTHOR]

Published
2022
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40. Gradient based iterative methods for solving symmetric tensor equations.

Author

Li, Tao, Wang, Qing‐Wen, and Zhang, Xin‐Fang

Subjects
NUMERICAL solutions to equations, POSITIVE systems, NONLINEAR equations, CONJUGATE gradient methods, EQUATIONS
Abstract

The steepest descent and conjugate gradient methods are classical gradient based iterative methods for solving symmetric positive definite linear system Ax=b. In this article, we are concerned with the numerical solution of the tensor equation 𝒜xm−1=b by those well‐known iterations in which 𝒜 is an mth order n‐dimensional symmetric tensor. Then we prove that the developed iterative methods converge locally linearly under some appropriate conditions. Finally, some numerical experiments are provided to illustrate the feasibility and effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]

Published
2022
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47. Hermitian and skew-Hermitian splitting methods for solving a tensor equation.

Author

Li, Tao, Wang, Qing-Wen, and Zhang, Xin-Fang

Subjects
HERMITIAN forms, EQUATIONS, EINSTEIN field equations, EINSTEIN manifolds
Abstract

The present paper deals with the numerical solution of non-Hermitian positive definite tensor equation A ∗ N X = B under the Einstein product. Firstly, we extend the Hermitian and skew-Hermitian splitting (HSS) method to solve the tensor equation. Then we propose a new Hermitian splitting (NHS) method under some certain conditions, which is expected to converge faster than the HSS iteration. We also present the optimal parameters of both the HSS and NHS methods. Moreover, we apply the Smith technique to give two modified methods which can greatly accelerate the convergence rate. The performed numerical examples illustrate that the proposed methods are feasible and efficient. [ABSTRACT FROM AUTHOR]

Published
2021
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