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IEEE/CAA Journal of Automatica Sinica 2020年第5期7卷 1335-1343页

作者： Lei liu Tingting Gao yan-jun liu Shaocheng Tong College of Science Liaoning University of TechnologyJinzhou 121001China IEEE

This paper concentrates on asymmetric barrier Lyapunov functions(ABLFs)based on finite-time adaptive neural network(NN)control methods for a class of nonlinear strict feedback systems with time-varying full state *** the process of backstepping recursion,the approximation properties of NNs are exploited to address the problem of unknown internal *** ABLFs are constructed to make sure that the time-varying asymmetrical full state constraints are always *** to the Lyapunov stability and finitetime stability theory,it is proven that all the signals in the closedloop systems are uniformly ultimately bounded(UUB)and the system output is driven to track the desired signal as quickly as possible near the *** the meantime,in the scope of finitetime,all states are guaranteed to stay in the pre-given ***,a simulation example is proposed to verify the feasibility of the developed finite time control algorithm.

关键词： Barrier Lyapunov functions constrained control finite time stability neural control

Adaptive Neural Control for Nonlinear MIMO Function Constraint Systems

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IEEE/CAA Journal of Automatica Sinica 2023年第3期10卷 816-818页

作者： Tianqi Yu yan-jun liu Lei liu College of Science Liaoning University of TechnologyJinzhou 121001China IEEE

Dear Editor,In this letter,a novel adaptive control design problem for uncertain nonlinear multi-input-multi-output(MIMO)systems with time-varying full state constraints is proposed,where the considered systems consist of various subsystems,and the states of each subsystem are interconnected *** is universally acknowledged that in the existing researches with state constraints,system constraint bounds are always constants or time-varying functions.

关键词： MIMO constraints Nonlinear

Fixed-Time Neural Control of a Quadrotor UAV With Input and Attitude Constraints

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IEEE/CAA Journal of Automatica Sinica 2023年第1期10卷 281-283页

作者： Benke Gao yan-jun liu Lei liu the School of Electrical Engineering Liaoning University of TechnologyJinzhou 121001China IEEE the College of Science Liaoning University of TechnologyJinzhou 121001China

Dear Editor, This letter is concerned with the attitude control of a quadrotor unmanned aerial vehicle(UAV) subject to the input constraint, attitude constraint and model uncertainty. Firstly, we construct an auxiliary system to eliminate the adverse impact of the input ***, we introduce the nonlinear state-dependent function to deal with the attitude constraint directly. Thirdly, the neural network is utilized to identify the unknown terms in the system. Finally.

关键词： Attitude constraint eliminate

Adaptive Neural Network-Based Control for a Class of Nonlinear Pure-Feedback Systems With Time-Varying Full State Constraints

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IEEE/CAA Journal of Automatica Sinica 2018年第5期5卷 923-933页

作者： Tingting Gao yan-jun liu Senior Member IEEE Lei liu Dapeng Li the college of science liaoning university of technologyJinzhou 121000，China ieee the school of electrical engineering liaoning university of technologyJinzhou 121000，China

Abstract--In this paper, an adaptive neural network （NN） control approach is proposed for nonlinear pure-feedback sys- tems with time-varying full state constraints. The pure-feedback systems of this paper are assumed to possess nonlinear function uncertainties. By using the mean value theorem, pure-feedback systems can be transformed into strict feedback forms. For the newly generated systems, NNs are employed to approximate unknown items. Based on the adaptive control scheme and backstepping algorithm, an intelligent controller is designed. At the same time, time-varying Barrier Lyapunov functions （BLFs） with error variables are adopted to avoid violating full state constraints in every step of the backstepping design. All closed- loop signals are uniformly ultimately bounded and the output tracking error converges to the neighborhood of zero, which can be verified by using the Lyapunov stability theorem. Two simulation examples reveal the performance of the adaptive NN control approach. Index TermsmAdaptive control, neural networks （NNs）, non- linear pure-feedback systems, time-varying constraints.

关键词： Adaptive control neural networks(NNs) nonlinear pure-feedback systems time-varying constraints

Biodesulfurization of vanadium-bearing titanomagnetite concentrates and pH control of bioleaching solution

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International Journal of Minerals,Metallurgy and Materials 2013年第10期20卷 925-930页

作者： Xiao-rong liu Sheng-cai Jiang yan-jun liu Hui Li Hua-jun Wang School of Materials Science and Engineering Shanghai Institute of Technology China Metallurgical Mining Corporation Civil and Environmental Engineering School University of Science and Technology Beijing

Vanadium-bearing titanomagnetite concentrates were desulfurized with Acidithiobacillus ferrooxidans （A. ferrooxidans）. The sulfur content of the concentrates was reduced from 0.69wt% to 0.14wt% after bioleaching for 15 d with a 10% pulp density at 30℃. Maintaining a stable pH value during biodesulfurization was critical because of high acid consumption, resulting from a combination of nonoxidative and oxidative dissolution of pyrrhotite in acid solution. It is discovered that the citric acid-disodium hydrogen phosphate buffer of pH 2.0 can control the solution pH value smoothly in the optimal range of 2.0-3.0 for A. ferrooxidans growth. Using the buffer in the volume fraction range of 5.0%-15.0% stimulates A. ferooxidans growth and improves the biodesulfurization efficiency. Compared with the buffer-free control case, the maximum increase of biodesulfurization rate is 29.7% using a 10.0vol% buffer. Bioleaching provides an alternative process for desulfurization of vanadium-bearing titanomagnetite ores.

关键词： titanomagnetite vanadium biodesulfurization Acidithiobacillus ferrooxidans citric acid disodium hydrogenphosphate

Estimation Based Adaptive Constraint Control for a Class of Coupled String Systems

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IEEE/CAA Journal of Automatica Sinica 2022年第8期9卷 1536-1539页

作者： Sai Zhang Li Tang yan-jun liu College of Science Liaoning University of TechnologyJinzhou 121001China

Dear editor,In this letter,the boundary tension constraint-based adaptive boundary control problem is investigated for a class of flexible string systems with unknown boundary disturbances and unknown parameters,with ... 详细信息

关键词： boundary letter constraint

In-situ monitoring of cell-secreted lactate by electrochemiluminescence sensing under biomimetic microfluidic confinement

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Chinese Chemical Letters 2022年第5期33卷 2705-2707页

作者： Yixin liu Yuanyuan Yao Beibei yang yan-jun liu Baohong liu Department of Chemistry Shanghai Stomatological Hospitaland State Key Lab of Molecular Engineering of PolymersFudan UniversityShanghai 200433China Shanghai Key Laboratory of Medical Epigenetics International Co-laboratory of Medical Epigenetics and Metabolism(Ministry of Science and Technology)Institutes of Biomedical SciencesFudan UniversityShanghai 200032China College of Biological Chemical Sciences and EngineeringJiaxing UniversityJiaxing 314001China Department of Chemistry and Chemical Engineering Nantong UniversityNantong 226000China

Cell migration proceeds in 3D matrices in vivo,which can naturally switch to distinct phenotypes for bet-ter invasion in confined *** studies of important metabolites under confinement are extremely meaningful for comprehensive insights into cancer *** integration of cell confine-ment device and analytical techniques is a key point for in-situ analysis of significant metabolites in ***,an electrochemiluminescence(ECL)sensing platform was designed for in-situ monitoring of cell-secreted lactate in highly confined *** 3-μm confiner was exactly fabricated via mi-crofabrication and microfluidics technique,and cells in high confinement and low adhesion tended to be round with contractile blebs on cell ***,in-situ monitoring of lactate was successfully achieved on the ECL platform with the catalysis of lactate oxidase,in which the levels in different time intervals were acquired in the luminol-hydrogen peroxide ***,the results were verified by the liquid chromatography-tandem mass spectrometry(LC-MS/MS)technology,which showed similar fluctuations with the ECL *** system offered an available avenue for metabolites analysis in highly confined microenvironments,which may advance deeper insights into metabolic mechanisms of cancer metastasis.

关键词： Confinement ECL sensing platform In-situ monitoring

Integral Barrier Lyapunov function-based adaptive control for switched nonlinear systems

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Science China(Information Sciences) 2020年第3期63卷 212-225页

作者： Lei liu yan-jun liu Aiqing CHEN Shaocheng TONG C.L.Philip CHEN College of Science Liaoning University of Technology Computer Science and Engineering South China University of Technology Navigation College Dalian Maritime University

This paper presents an adaptive control method for a class of uncertain strict-feedback switched nonlinear systems. First, we consider the constraint characteristics in the switched nonlinear systems to ensure that all states in switched systems do not violate the constraint ranges. Second, we design the controller based on the backstepping technique, while integral Barrier Lyapunov functions(i BLFs) are adopted to solve the full state constraint problems in each step in order to realize the direct constraints on state ***, we introduce the Lyapunov stability theory to demonstrate that the adaptive controller achieves the desired control goals. Finally, we perform a numerical simulation, which further verifies the significance and feasibility of the presented control scheme.

关键词： adaptive control switched nonlinear systems integral Barrier Lyapunov functions backstepping technique full state constraints

Novel chiral thioureas for highly enantioselective Michael reactions of malonates to nitroalkenes

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Chinese Chemical Letters 2009年第3期20卷 310-313页

作者： Li jun yan Quan Zhong liu Xue Lian Wang Laboratory of Applied Chemistry and Pollution Control Technology College of Chemistry and Chemical Engineering China West Normal University Nanchong 637002 China

Highly efficient Michael addition reactions of malonates to nitroalkenes catalyzed by novel chiral thioureas derived from optically pure BINOL and amino acids are reported. Various trans-nitroalkenes reacted with malo... 详细信息

关键词： Michael addition Thiourea Enantioselectivities Nitroalkene and malonate

A New Antimicrobial Flavonol Glycoside from Alchornea davidii

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Chinese Chemical Letters 2003年第2期14卷 179-180页

作者： Gui You CUI jun yan liu Ren Xiang TAN Institute of Functional Biomolecules School of Life SciencesNanjing UniversityNanjing 210093

A new flavonol glycoside, isorhamnetin-3-O-b-D-xyloside, was isolated from the extract of leaves and twigs of Alchornea davidii (Euphorbiaceae). Its structure was established on the basis of the spectral analysis and chemical degradation. Antimicrobial assay showed that it moderately inhibited the growth of test bacteria (Staphylococcus aureus, Bacillus subtilis and Pseudomonas fluorescens) and fungi (Candida albicans, Aspergillus niger and Trichophyton rubrum) with MICs at 50 g/mL.

关键词： Alchornea davidii Euphorbiaceae flavonol glycoside antimicrobial activity.