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Cobalamin-dependent radical S-adenosyl-L-methionine protein functions with a partner to successively methylate tricyclic indole alkaloid for chuangxinmycin maturation and derivatization

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science China Chemistry 2025年第1期 308-316页

作者： Sili Wang Jiancheng Huang Yanan Du Wei Huang Yufeng Xue Xiaokun Xu Guannan Zhong Yuanyuan Shi Bin Hong Xiaoying Bian Wen Liu State Key Laboratory of Chemical Biology Shanghai Institute of Organic Chemistry University of Chinese Academy of SciencesChinese Academy of Sciences State Key Laboratory of Microbial technology Shandong University National Health Commission (NHC) Key Laboratory of Biotechnology for Microbial Drugs Institute of Medicinal BiotechnologyChinese Academy of Medical Science & Peking Union Medical College

Cobalamin(Cbl)-dependent radical S-adenosyl-L-methionine(SAM) proteins constitute the largest collection of the radical SAM superfamily that has hundreds of thousands of individual members. Many of these proteins are involved in the biosynthesis of pharmaceutically important natural products to catalyze chemically demanding reactions. In the biosynthetic pathway of chuangxinmycin(CXM), a unique indole alkaloid antibiotic with potent anti-infective activity, functionalization of the characteristic thiopyrano[4,3,2-cd]indole scaffold by regio-and stereoselective C3-methylation is believed to rely on a Cbl-dependent radical process, which, however, remained to be reconstituted biochemically. We here report the dissection of this enzymatic process, which requires the incorporation of Cxm8, a Cbl-dependent radical SAM protein, with Cxm9, a DUF5825family protein that shares no homology to any proteins of known functions. Cxm8 and Cxm9 function together by forming an unexpected heterodimeric complex that selectively catalyzes C3-methylation of the tricyclic indole-S-hetero ring system in a successive manner, achieving CXM and a recently identified, C3-dimethylated congener. Detailed biochemical characterization,isotope labeling, structural simulation and bioinformatics analysis rationalized the catalysis of the Cxm8/Cxm9 complex and particularly the necessity of the DUF5825 protein for C3-methylase activity. This is the first example that a Cbl-dependent protein acts with a partner to exhibit radical SAM activity.

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Observer-Based Controller Design for Singular Stochastic Markov Jump systems with State Dependent Noise

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Journal of systems science & Complexity 2016年第4期29卷 946-958页

作者： ZHAO Yong ZHANG Weihai college of Electrical Engineering and Automation and college of mathematics and systems science Shandong University of Science and TechnologyQingdao 266590China college of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China

This paper is concerned with the problem of observer-based controller design for singular stochastic Markov jump systems with state-dependent noise. Two concepts called "non-impulsiveness"and "mean square admissibility" are introduced, which are different from previous ones. Sufficient conditions for the open-and closed-loop singular stochastic Markov jump systems with state-dependent noise to be mean square admissible are provided in terms of strict LMIs. The controller gain and the observer gain which guarantee the resulting closed-loop error system to be mean square admissible are obtained in turn by solving the strict LMIs. A numerical example is presented to show the efficiency of the design approach.

关键词： Linear matrix inequalities observer-based controller singular stochastic systems stability.

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The (3+1)-dimensional generalized mKdV-ZK equation for ion-acoustic waves in quantum plasmas as well as its non-resonant multiwave solution

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Chinese Physics B 2020年第12期29卷 329-339页

作者： Xiang-Wen Cheng Zong-Guo Zhang Hong-Wei Yang college of mathematics and systems science Shandong University of Science and TechnologyQingdao 266590China School of mathematics and Statistics Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China

The quantum hydrodynamic model for ion-acoustic waves in plasmas is ***,we design a new disturbance expansion to describe the ion fluid velocity and electric field *** should be emphasized that the piecewise function perturbation form is new with great difference from the previous ***,based on the piecewise function perturbation,a(3+1)-dimensional generalized modified Korteweg–de Vries Zakharov–Kuznetsov(mKdV-ZK)equation is derived for the first time,which is an extended form of the classical mKdV equation and the ZK ***(3+1)-dimensional generalized time-space fractional mKdV-ZK equation is constructed using the semi-inverse method and the fractional variational ***,it is more accurate to depict some complex plasma processes and ***,the conservation laws of the generalized time-space fractional mKdV-ZK equation are ***,using the multi-exponential function method,the non-resonant multiwave solutions are constructed,and the characteristics of ion-acoustic waves are well described.

关键词： ion-acoustic waves piecewise function perturbation (3+1)-dimensional generalized time-space fractional mKdV-ZK equation non-resonant multiwave solution

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Soliton solution to the complex modified Korteweg–de Vries equation on both zero and nonzero background via the robust inverse scattering method

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Communications in Theoretical Physics 2022年第7期74卷 30-40页

作者： Yong Zhang Yanwei Ren Huanhe Dong college of mathematics and systems science Shandong University of Science and TechnologyQingdao 266590China college of Economics and Management Shandong University of Science and TechnologyQingdao 266590China

In this paper, based on the robust inverse scattering method, we construct two kinds of solutions to the focusing modified Korteweg–de Vries equation. One is the classical soliton solution under the zero background condition and the other one is given through the nonzero ***, for the nonzero background case, we choose a special spectral parameter such that the nonzero background solution is changed into the rational travelling waves. Finally, we also give a simple analysis of the soliton as the time t is large, then we give the comparison between the exact solution and the asymptotic solution.

关键词： robust inverse scattering method modified Korteweg-de Vries equation soliton solution rational travelling waves asymptotic analysis

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Magnetohydrodynamics hemodynamics hybrid nanofluid flow through inclined stenotic artery

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Applied mathematics and Mechanics(English Edition) 2023年第3期44卷 459-476页

作者： B.K.SHARMA R.GANDHI T.ABBAS M.M.BHATTI Department of mathematics Birla Institute of Technology and SciencePilani 333031India Department of mathematics Division of Science and TechnologyUniversity of EducationLahore 54770Pakistan college of mathematics and systems science Shandong University of Science and TechnologyQingdao 266590Shandong ProvinceChina

The present study aims to perform computational simulations of twodimensional(2D)hemodynamics of unsteady blood flow via an inclined overlapping stenosed artery employing the Casson fluid model to discuss the hemorheological properties in the arterial region.A uniform magnetic field is applied to the blood flow in the radial direction as the magneto-hemodynamics effect is *** entropy generation is discussed using the second law of *** influence of different shape parameters is explored,which are assumed to have varied shapes(spherical,brick,cylindrical,platelet,and blade).The Crank-Nicolson scheme solves the equations and boundary conditions governing the *** a given critical height of the stenosis,the key hemodynamic variables such as velocity,wall shear stress(WSS),temperature,flow rate,and heat transfer coefficient are computed.

关键词： overlapping stenosis hematocrit-dependent viscosity Au-Cu/blood hybrid nanofluid entropy generation shape effect

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Prescribed Performance Finite-Time Tracking Control for Uncertain Nonlinear systems

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Journal of systems science & Complexity 2019年第3期32卷 803-817页

作者： JING Yuanwei LIU Yang ZHOU Shaowei college of Information science and Engineering Northeastern University Shenyang 110819 China college of mathematics and systems science Shandong University of Science and Technology Qingdao 266590 China

This work investigates the finite-time tracking control problem for a class of uncertain strict-feedback nonlinear systems from a new perspective. First, a novel concept called finite-time performance function (FTPF) is defined. Further, a new sufficien t condition of finite-time st ability is derived and the tracking error can converge to a predefined region within a finite-time interval. The design process of the proposed technique is simpler. Finally, four simulation examples are carried out to illustrate the effectiveness of presented method.

关键词： Finite-time boundedness prescribed performance control uncertain nonlinear systems

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Survey on applications of algebraic state space theory of logical systems to finite state machines

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science China(Information sciences) 2023年第1期66卷 5-24页

作者： Yongyi YAN Daizhan CHENG Jun-E FENG Haitao LI Jumei YUE college of Information Engineering Henan University of Science and Technology Institute of systems science Chinese Academy of Sciences School of mathematics Shandong University School of mathematics and Statistics Shandong Normal University college of Agricultural Equipment Engineering Henan University of Science and Technology

Algebraic state space theory(ASST) of logical systems, developed based on the semi-tensor product(STP) which is a new matrix analysis tool built in recent ten years, provides an algebraic analysis approach for many fields of science, such as logical dynamical systems, finite-valued systems, discrete event dynamic systems, and networked game systems. This study focuses on comprehensively surveying the applications of the ASST method to the field of finite state machines(FSMs). Some necessary preliminaries on the method are first reviewed. Then the applications of the method in the FSM field are reviewed, including deterministic FSMs, nondeterministic FSMs, probabilistic FSMs, networked FSMs, and controlled and combined FSMs. In addition, other applications related to both STP and FSMs are surveyed, such as the application of FSM to Boolean control networks and the application of graph theory to FSMs. Finally, some potential research directions with respect to the ASST method in the FSM field are predicted.

关键词： Boolean control network Boolean network finite state machine learning system semi-tensor product (STP) ASST

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An Online Exploratory Maximum Likelihood Estimation Approach to Adaptive Kalman Filtering

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IEEE/CAA Journal of Automatica Sinica 2025年第1期 228-254页

作者： Jiajun Cheng Haonan Chen Zhirui Xue Yulong Huang Yonggang Zhang the college of Intelligent systems science and Engineering Harbin Engineering University the Engineering Research Center of Navigation Instruments Ministry of Education the college of Intelligent systems science and Engineering the college of Future technology Harbin Engineering University IEEE

Over the past few decades, numerous adaptive Kalman filters(AKFs) have been proposed. However, achieving online estimation with both high estimation accuracy and fast convergence speed is challenging, especially when both the process noise and measurement noise covariance matrices are relatively inaccurate. Maximum likelihood estimation(MLE) possesses the potential to achieve this goal, since its theoretical accuracy is guaranteed by asymptotic optimality and the convergence speed is fast due to weak dependence on accurate state ***, the maximum likelihood cost function is so intricate that the existing MLE methods can only simply ignore all historical measurement information to achieve online estimation,which cannot adequately realize the potential of MLE. In order to design online MLE-based AKFs with high estimation accuracy and fast convergence speed, an online exploratory MLE approach is proposed, based on which a mini-batch coordinate descent noise covariance matrix estimation framework is developed. In this framework, the maximum likelihood cost function is simplified for online estimation with fewer and simpler terms which are selected in a mini-batch and calculated with a backtracking method. This maximum likelihood cost function is sidestepped and solved by exploring possible estimated noise covariance matrices adaptively while the historical measurement information is adequately utilized. Furthermore, four specific algorithms are derived under this framework to meet different practical requirements in terms of convergence speed, estimation accuracy,and calculation load. Abundant simulations and experiments are carried out to verify the validity and superiority of the proposed algorithms as compared with existing state-of-the-art AKFs.

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Existence of Nontrivial Solutions for Superlinear Three-Point Boundary Value Problems

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Acta Mathematicae Applicatae Sinica 2017年第4期33卷 1043-1052页

作者： Hong-yu LI college of mathematics and systems science Shandong University of Science and Technology Qingdao 266590China mathematics and science college Shanghai Normal University Shanghai 200234 China

In this paper, we investigate the existence of nontrivial solutions for some superlinear second order three-point boundary value problems by applying new fixed point theorems in ordered Banach spaces with the lattice ... 详细信息

关键词： lattice three-point boundary value problem sign-changing solution

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Haken 3-Manifolds in Small Covers

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Chinese Annals of mathematics,Series B 2023年第4期44卷 549-560页

作者： Lisu WU Li YU college of mathematics and systems science Shandong University of Science and TechnologyTsingtao 266590ShandongChina Department of mathematics Nanjing UniversityNanjing 210093China

The authors prove that a 3-dimensional small cover M is a Haken manifold if and only if M is aspherical or equivalently the underlying simple polytope is a flag *** addition,they find that M being Haken is also equiva... 详细信息

关键词： Small cover Haken manifold Incompressible surface Flag polytope

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