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A novel adaptive-impulsive synchronization of fractional-order chaotic systems

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Chinese Physics B 2015年第10期24卷 86-92页

作者： Leung Y.T.Andrew li xian-feng Chu Yan-Dong Zhang Hui Department of Architecture and Civil Engineering City University of Hong Kong School of Mathematics and Physics Lanzhou Jiaotong University School of Mechatronic Engineering Lanzhou Jiaotong University

A novel adaptive-impulsive scheme is proposed for synchronizing fractional-order chaotic systems without the necessity of knowing the attractors＇ bounds in priori. The nonlinear functions in these systems are supposed to satisfy local lipschitz conditions but which are estimated with adaptive laws. The novelty is that the combination of adaptive control and impulsive control offers a control strategy gathering the advantages of both. In order to guarantee the convergence is no less than an expected exponential rate, a combined feedback strength design is created such that the symmetric axis can shift freely according to the updated transient feedback strength. All of the unknown lipschitz constants are also updated exponentially in the meantime of achieving synchronization. Two different fractional-order chaotic systems are employed to demonstrate the effectiveness of the novel adaptive-impulsive control scheme.

关键词： adaptive-impulsive synchronization fractional order chaotic systems combined feedbackstrength

Symmetry and Period-Adding Windows in a Modified Optical Injection Semiconductor Laser Model

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Chinese Physics Letters 2012年第1期29卷 1-4页

作者： li xian-feng Andrew Y-T.Leung CHU Yan-Dong Department of Mathematics Lanzhou Jiaotong UniversityLanzhou 730070 Department of Civil and Architectural Engineering City University of Hong KongHong Kong

Hierarchical structural symmetry of periodic islands embedded in the chaotic region of modified optical injection semiconductor lasers(MOISLs)is expounded upon in phase *** onset of the bifurcation cascade shows remarkable accumulation *** cascade follows a specific period-adding ***-similarities and infinite spiral nestings shrinking beyond a certain point of the periodic hub are revealed to affirm the existence of self-organized distribution of periodicity and chaos in phase diagrams.

关键词： periodic bifurcation symmetry

Development of a monolithic polymer pipette for solid-phase extraction of liquiritigenin in rat plasma

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Chinese Chemical Letters 2012年第6期23卷 723-726页

作者： Hong Wu Zhang Kang li Zhi xian liang feng YangWang Qi Wen Lu School of Pharmacy Guangdong Pharmaceutical College Guangzhou 510006 China

A monolithic polymer column with mixed-mode interaction was prepared by in situ polymerization in a 1000μL pipette. Two kinds of monomers, butyl methacrylate （BMA） and 2-（dimethylamino）ethyl methacrylate （DMAM） were applied to constructing the mixed-mode interaction of monolithic polymer column. Its solid-phase extraction properties for liquiritigenin （LQG） were evaluated by high performance liquid chromatography （HPLC） with a gradient elution procedure. After the extraction procedure was optimized, the maximum binding capacity and extraction recovery following the optimal extraction procedure were investigated. Calibration curve was expressed as A = 65.9C ＋ 4.53 （r2 = 0.998） with a linear range of 0.151-1.80μg/mL. The experimental results indicate that the monolithic polymer pipette presents good extraction efficiency for LQG. It can be envisaged that the developed monolithic polymer pipette possesses the potential for its application to the enrichment of other flavonoids compounds being similar to the structure of LQG.

关键词： Monolithic polymer pipette Solid phase extraction High performance liquid chromatography liquiritigenin

Spatiotemporal changeof vegetationcoverage recovery and its driving factors in the Wenchuan earthquake-hit areas

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Journal of Mountain Science 2021年第11期18卷 2854-2869页

作者： SUN Xiao-fei YUAN lin-guo ZHOU Ying-zhi SHAO Huai-yong li xian-feng ZHONG Ping Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 611756China College of Earth Science Chengdu University of TechnologyChengdu 610059China Natural Resources and Planning Bureau of Nanchong Nanchong 637000China Department of Geography National University of SingaporeKent Ridge 117570Singapore

Vegetation coverage recovery after the Wenchuan earthquake has important implications for preventing post-seismic geohazards and soil ***,spatiotemporal changes in vegetation coverage recovery and its driving factors have not been sufficiently studied in the quake-hit *** paper aims to analyze vegetation coverage recovery and its driving factors in the quake-hit areas using monadic linear regression,coefficient of variation,and geographical ***,we used Moderate-resolution Imaging Spectroradiometer(MODIS)data to calculate the vegetation coverage from 2008 to 2018 in the quake-hit ***,we assessed the trend and stability of vegetation recovery in the quake-hit areas based on vegetation ***,combined with topography,climate,soil type,vegetation type,and human activities in the quake-hit areas,the driving factors affecting vegetation coverage recovery were *** results showed that the vegetation coverage level in the quake-hit areas recovered about 90%of that before the *** coverage recovery was mainly improved in a stepwise manner:increasing and then stabilizing,then increasing and stabilizing ***,soil type,and road density were the main factors affecting vegetation coverage recovery,and the interaction among all factors positively strengthened their impacts on vegetation coverage *** addition,the results also revealed the categories that were conducive to vegetation coverage recovery among the same environmental factors and can provide a scientific reference for vegetation coverage recovery in the quake-hit areas.

关键词： Wenchuan earthquake Vegetation coverage recovery Geographical detector Driving factors

Evolution of Morphology and Properties of Sulfonated Poly(ether ether ketone ketone) Membranes Fabricated via Electrospinning

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Chemical Research in Chinese Universities 2010年第1期26卷 157-160页

作者： MA Hai-song HAO Xiu-feng li xian-feng ZHAO Cheng-ji FU Tie-zhu NA Hui ZHANG Ming-lei Alan G. MacDiarmid Institute College of Chemistry Jilin University Changchun 130012 P. R. China Prosthetic Department of the Hospital of Stomatology Jilin University Changchun 130021 P. R. China

Sulfonated poly（ether ether ketone kctone）（SPEEKK） membranes with different degrees of sulfonation（DS） were successfully prepared via electrospinning method. The morphology of the resulted membranes varies from nanospheres to nanofibers with increasing the concentration of SPEEKK. The conductivities of the membranes prepared under the same condition increase with the DS increasing. The spherical morphological membranes with a DS of 1.2 show the highest proton conductivity, 0.55 S/cm, which is much higher than those of the membranes prepared via normal solution evaporation method. The results show that electrospinning is an efficient method to prepare high performance SPEEKK membranes with different morphologies.

关键词： Proton conductivity Electrospinning Membrane

Mechanical Properties and Microstructure of In Situ TiB_2-7055 Composites

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Chinese Journal of Aeronautics 2006年第B12期19卷 66-70页

作者： CHEN dong LE Yong-kang BAI liang MA Nai-heng li xian-feng WANG Hao-wei The State Key laboratory of Metal Matrix Composites Shanghai Jiao Tong University Shanghai 200030 China

In order to fabricate a kind of high strength particulate reinforced aluminum-matrix composites, the high strength aluminum alloy 7055 was selected as a matrix. Composites reinforced with varying amounts of TiB2 particles were synthesized using the in situ method, and their mechanical properties and microstructure were analyzed. It is found that the in situ TiB2 particles sized from 50 to 400 um uniformly disperse in the matrix. With the weight fraction of TiB2 particles increasing, the elastic modulus as well as the yield strength and the ultimate tensile strength increase, while the ductility decrease. The improvement of strength could be attributed to good bonding between TiB2 and the matrix, and also the TiB2 particles act as a barrier to dislocation.

关键词： metal matrix composite in situ mechanical properties microstructure

Least squares weighted twin support vector machines with local information

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Journal of Central South University 2015年第7期22卷 2638-2645页

作者：花小朋徐森李先锋 School of Information Engineering Yancheng Institute of Technology School of Computer Science and Technology China University of Mining and Technology

A least squares version of the recently proposed weighted twin support vector machine with local information(WLTSVM) for binary classification is formulated. This formulation leads to an extremely simple and fast algorithm, called least squares weighted twin support vector machine with local information(LSWLTSVM), for generating binary classifiers based on two non-parallel hyperplanes. Two modified primal problems of WLTSVM are attempted to solve, instead of two dual problems usually solved. The solution of the two modified problems reduces to solving just two systems of linear equations as opposed to solving two quadratic programming problems along with two systems of linear equations in WLTSVM. Moreover, two extra modifications were proposed in LSWLTSVM to improve the generalization capability. One is that a hot kernel function, not the simple-minded definition in WLTSVM, is used to define the weight matrix of adjacency graph, which ensures that the underlying similarity information between any pair of data points in the same class can be fully reflected. The other is that the weight for each point in the contrary class is considered in constructing equality constraints, which makes LSWLTSVM less sensitive to noise points than WLTSVM. Experimental results indicate that LSWLTSVM has comparable classification accuracy to that of WLTSVM but with remarkably less computational time.

关键词： least squares similarity information hot kernel function noise points

The model of taking electronic medical records as the core for information construction in hospitals＂

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Chinese Medical Journal 2013年第2期126卷 373-377页

作者： WU Tao XU Ke li Ping li xian-feng XU Wei-guo Xinhua Hospital Shanghai Jiao Tong University School ofMedicine Shanghai 200092 China

The development of hospital information has been carried out for nearly 50 years, and originally started Le hospital information system （HIS）1 So far HIS isas the hospital information system （HIS）J So far HIS is the most widely and deeply used management system for hospitals in China.2 ＂General function standard for hospital information system＂ issued by China＇s Ministry of Health in 2002 defined that ＂The hospital information system refers to using of computer hardware and software technology, network communications technology, and other modem technology to comprehensively manage personnel, logistics, and finance in various departments in hospital. Gather, store, treat, extract, transport, aggregate,and process data in various stages of the medical activities, so that provide comprehensive and automatic information management and service to the hospital.＂

关键词： electronic medical record hospital information construction

Near-Yrast Structures in Odd-Odd 122I Nucleus

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Chinese Physics Letters 2012年第9期29卷 40-44页

作者： liU Gong-Ye li li li xian-feng YU De-Yang SUN Ji li Cong-Bo MA Ying-Jun WU Xiao-Guang HE Chuang-Ye ZHENG Yun ZHU li-Hua ZHAO Yan-Xin College of Physics Jilin UniversityChangchun 130012 China Institute of Atomic Energy Beijing 102413 School of Physics and Nuclear Energy Engineering Beihang UniversityBeijing 100191 Department of Physics Heilongjiang UniversityHaerbin 150080

Excited states of the odd-odd nucleus 122I are investigated via the fusion-evaporation reaction 116Cd(11B,5n)at a beam energy of 68 *** two most strongly populated bands in 122I are observed up to excitation energies around 10.5 *** possible configurations at lower spins are assigned toπh_(11/2)■νh_(11/2) andπh_(11/2)■νd_(5/2) based on the observed population,B(M1)/B(E2)values,alignments and signature splitting.E1 transitions are observed connecting theπh_(11/2)■νd_(5/2) band to theπh_(11/2)■νh_(11/2) band,which may be evidence of octupole *** terminations caused by the full alignment of the valence nucleons outside the 114Sn core are observed in both bands.

关键词： bands alignment connecting