Nitrogen-containing graphene networks with high volumetric capacitance and exceptional rate capability
作者：
Wang, Deping;Hu, Wenming;Ma, Qian;Zhang, Xuefang;Xia, Xiaohong* ;...
期刊：
Carbon ,2019年154:13-23 ISSN：0008-6223
通讯作者：
Xia, Xiaohong;Liu, Hongbo
作者机构：
[Wang, Deping] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Hu, Wenming; Chen, Hui; Xia, Xiaohong; Ma, Qian; Xia, XH; Liu, HB; Zhang, Xuefang; Liu, Hongbo] Hunan Univ, Coll Mat Sci & Engn, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Xia, XH; Liu, HB] H;Hunan Univ, Coll Mat Sci & Engn, Changsha 410082, Hunan, Peoples R China.
关键词：
Graphene networks;Nitrogen-containing;Rate capability;Volumetric capacitance
摘要：
Graphene has attracted more attention as advanced electrodes for supercapacitors due to its unique geometry structure and outstanding physicochemical property. But its low specific capacitance, especially low volumetric capacitance, has greatly restricted the practical application of graphene electrode materials. Herein, we synthesized nitrogen-containing graphene networks by using 2, 3-diaminopyridine (O-DAP) as functional agent in a facile hydrothermal route. During the hydrothermal process, not only the pyrrolic-N, but also the pyrazine-N is produced in the graphene lattice at the edge/defect site of graphene because of the double –NH2 in DAP reactant. Owing to the high nitrogen content (17.5 at%), special nitrogen configuration, and high density (1.66 g cm−3), the N-containing graphene networks present high gravimetric capacitances up to 353 F g−1 and high volumetric capacitances over 586 F cm−3 in 1 M H2SO4 electrolyte. More remarkably, the N-containing graphene electrodes exhibit exceptional rate capability with a capacitance retention of 80.6% at a high current density of 20 A g−1 and good cycling stability of 91.5% retention after 5000 cycles in a symmetrical two-electrode configuration. © 2019 Elsevier Ltd
语种：
英文
展开
Silver coordination complex amplified electrochemiluminescence sensor for sensitive detection of coenzyme A and histone acetyltransferase activity
作者：
Chen, Hongjun;Liu, Xiu;Li, Wang* ;Peng, Yan;Nie, Zhou
期刊：
Biosensors and Bioelectronics ,2019年126:535-542 ISSN：0956-5663
通讯作者：
Li, Wang
作者机构：
[Chen, Hongjun] Hunan Univ Humanities Sci & Technol, Sch Mat & Environm Engn, Hunan Prov Key Lab Fine Ceram & Powder Mat, Loudi 417000, Peoples R China.;[Chen, Hongjun; Li, Wang; Nie, Zhou] Hunan Univ, Coll Chem & Chem Engn, State Key Lab Chemo Biosensing & Chemometr, Changsha 410082, Hunan, Peoples R China.;[Liu, Xiu] Hunan Univ Humanities Sci & Technol, CICFWC, Key Lab Pesticide Harmless Applicat, Loudi 417000, Peoples R China.;[Li, Wang] Cent South Univ Forestry & Technol, Natl Engn Lab Deep Proc Rice & Byprod, Changsha 410004, Hunan, Peoples R China.;[Peng, Yan] Hengyang Normal Univ, Coll Econ & Management, Hengyang 421008, Peoples R China.
通讯机构：
[Li, Wang] C;Cent South Univ Forestry & Technol, Natl Engn Lab Deep Proc Rice & Byprod, Changsha 410004, Hunan, Peoples R China.
关键词：
ECL amplification;Histone acetyltransferase;Signal-on;Silver coordination complex
摘要：
A kind of coenzyme A (CoA)-silver coordination complex (CoA-Ag) was in-situ developed and verified to accelerate the electron transferring and electrochemical catalysis of H2O2 decomposition to enhance the cathode ECL intensity of CdTe@CdS QDs. Afterward, a convenient label-free signal-on ECL approach was constructed for CoA detection with excellent specificity. In addition, the unique ECL enhancing phenomenon was also proposed to assay the enzymatic activity of histone acetyltransferases (HAT) and screen relevant inhibitors, exhibiting a promising potential in the practical application of biochemical research, disease diagnosis and drug discovery.
语种：
英文
展开
Existence and Multiplicity of Solutions for Semilinear Elliptic Systems with Periodic Potential
作者：
Che, Guofeng;Chen, Haibo* ;Yang, Liu
期刊：
Bulletin of the Malaysian Mathematical Sciences Society ,2019年42(4):1329-1348 ISSN：0126-6705
通讯作者：
Chen, Haibo
作者机构：
[Che, Guofeng; Chen, Haibo] Cent S Univ, Sch Math & Stat, Changsha 410083, Hunan, Peoples R China.;[Yang, Liu] Hengyang Normal Univ, Sch Math & Stat, Hengyang 421002, Peoples R China.
通讯机构：
[Chen, Haibo] C;Cent S Univ, Sch Math & Stat, Changsha 410083, Hunan, Peoples R China.
关键词：
Ground state;Nehari–Pankov manifold;Semilinear elliptic systems;Strongly indefinite functional;Variational methods
摘要：
In this paper, we consider the following semilinear elliptic systems:
$$\begin{aligned} \left\{ \begin{array}{ll} \displaystyle -\Delta u+V(x)u=F_{u}(x, u, v),\quad \text{ in } \mathbb {R}^{N},\\ -\Delta v+V(x)v=F_{v}(x, u, v),\quad \text{ in } \mathbb {R}^{N},\\ \end{array} \right. \end{aligned}$$
where
$$V:\mathbb {R}^{N}\rightarrow \mathbb {R},~F_{u}(x,u,v)$$
and
$$F_{v}(x,u,v)$$
are periodic in x. We assume that 0 is a right boundary point of the essential spectrum of
$$-\triangle +V$$
. Under appropriate assumptions on
$$F_{u}(x, u, v)$$
and
$$F_{v}(x, u, v)$$
, we prove the above system has a ground-state solution by using the Nehari-type technique in a strongly indefinite setting. Furthermore, the existence of infinitely many geometrically distinct solutions is obtained via variational methods. Recent results from the literature are improved and extended.
语种：
英文
展开
Normal estimation via shifted neighborhood for point cloud
作者：
Cao, Junjie;Chen, He;Zhang, Jie* ;Li, Yujiao;Liu, Xiuping;...
期刊：
Journal of Computational and Applied Mathematics ,2018年329:57-67 ISSN：0377-0427
通讯作者：
Zhang, Jie
作者机构：
[Liu, Xiuping; Li, Yujiao; Cao, Junjie; Chen, He] Dalian Univ Technol, Sch Math Sci, Dalian, Peoples R China.;[Cao, Junjie] Nanchang Hangkong Univ, Coll Math & Informat Sci, Nanchang, Jiangxi, Peoples R China.;[Zhang, Jie] Liaoning Normal Univ, Sch Math, Dalian, Peoples R China.;[Zou, Changqing] Hengyang Normal Univ, Hengyang, Hunan, Peoples R China.
通讯机构：
[Zhang, Jie] L;Liaoning Normal Univ, Sch Math, Dalian, Peoples R China.
会议名称：
International Conference on Information and Computational Science (ICICS)
会议时间：
AUG 02-06, 2016
会议地点：
Dalian Univ Technol, Dalian, PAKISTAN
会议主办单位：
Dalian Univ Technol
关键词：
Normal estimation;Point cloud;Neighborhood shift
摘要：
For accurately estimating the normal of a point, the structure of its neighborhood has to be analyzed. All the previous methods use some neighborhood centering at the point, which is prone to be sampled from different surface patches when the point is near sharp features. Then more inaccurate normals or higher computation cost may be unavoidable. To conquer this problem, we present a fast and quality normal estimator based on neighborhood shift. Instead of using the neighborhood centered at the point, we wish to locate a neighborhood containing the point but clear of sharp features, which is usually not centering at the point. Two specific neighborhood shift techniques are designed in view of the complex structure of sharp features and the characteristic of raw point clouds. The experiments show that our method out-performs previous normal estimators in either quality or running time, even in the presence of noise and anisotropic sampling. © 2017 Elsevier B.V.
语种：
英文
展开
Pyridine-enriched graphene sheets for high volumetric performance supercapacitors
作者：
Zhang, Xuefang;Wang, Deping;Yang, Min;Xia, Xiaohong* ;Chen, Hui;...
期刊：
Journal of Solid State Electrochemistry ,2018年22(6):1921-1931 ISSN：1432-8488
通讯作者：
Xia, Xiaohong;Liu, Hongbo
作者机构：
[Chen, Hui; Chen, Yuxi; Yang, Min; Xia, Xiaohong; Xia, XH; Liu, HB; Zhang, Xuefang; Liu, Hongbo] Hunan Univ, Coll Mat Sci & Engn, Changsha, Hunan, Peoples R China.;[Wang, Deping] Hengyang Normal Univ, Coll Chem & Mat Sci, Hengyang 421008, Hunan, Peoples R China.;[Chen, Yuxi; Xia, Xiaohong; Xia, XH; Liu, HB; Liu, Hongbo] Hunan Univ, Hunan Prov Key Lab Adv Carbon Mat & Appl Technol, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Xia, XH; Liu, HB] H;Hunan Univ, Coll Mat Sci & Engn, Changsha, Hunan, Peoples R China.;Hunan Univ, Hunan Prov Key Lab Adv Carbon Mat & Appl Technol, Changsha 410082, Hunan, Peoples R China.
关键词：
Capacitance;Electrolytes;Nitrogen;Pyridine;Redox reactions;Supercapacitor;2,6-diaminopyridine;Capacitance retention;Gravimetric capacitance;High nitrogen content;High volumetric performance;Mild reaction conditions;Pseudocapacitance;Reversible redox reactions;Graphene
摘要：
Pyridine-enriched graphene sheets (DAP-RGOs) have been successfully prepared at mild reaction conditions from graphene oxide (GO) and 2, 6-diaminopyridine (DAP). High nitrogen content in DAP-RGOs can be readily achieved in a range of 13.1– 17.2% by controlling the feed ratios of reactants. The pyridine moieties grafted on the graphene sheets take place a reversible redox reaction and demonstrate faradaic capacitive behavior. Due to its high density (1.59 g cm−3) and reasonable nitrogen content (14.4%), the as-prepared DAP-RGO sample exhibits both high volumetric and gravimetric capacitances of 504 F cm−3 and 317 F g−1 at current density of 0.1 A g−1 in 1 M H2SO4 electrolyte, respectively. Furthermore, the assembled supercapacitor shows an excellent cycling stability with capacitance retention of 90% after 5000 cycles at 2 A g−1 ©Springer-Verlag GmbH Germany, part of Springer Nature 2018
语种：
英文
展开
Generation of double-ring-shaped cylindrical vector beams by modulating Pancharatnam–Berry phase
作者：
Chen, Huan;Ling, Xiaohui;Li, Qianguang;Lv, Hao;Yu, Huaqing;...
期刊：
Optik ,2017年134:227-232 ISSN：0030-4026
通讯作者：
Yi, Xunong
作者机构：
[Li, Qianguang; Chen, Huan; Yi, Xunong; Lv, Hao; Yu, Huaqing] Hubei Engn Univ, Coll Phys & Elect Informat Engn, Xiaogan 432000, Peoples R China.;[Ling, Xiaohui] Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421002, Peoples R China.;[Chen, Huan; Yi, Xunong] Hubei Engn Univ, Hubei Key Lab Qual Control Characterist Fruits &, Xiaogan 432000, Peoples R China.
通讯机构：
[Yi, Xunong] H;Hubei Engn Univ, Coll Phys & Elect Informat Engn, Xiaogan 432000, Peoples R China.
关键词：
Fruits;Gaussian distribution;Polarization;Vectors;Berry phase;Circularly polarized;Coherent superpositions;Cylindrical vector beam;Gaussian components;Jones matrix;Polarization angle;Vector beams;Gaussian beams
摘要：
In this work, we propose a method for generating double-ring-shaped cylindrical vector beams by modulating Pancharatnam–Berry phase (PBP). The theoretical analysis shows that the output field can be expressed as the coherent superposition of two circularly polarized Laguerre–Gaussian components with opposite polarization handness and opposite helical index when a linearly polarized fundamental Gaussian beam inputs the metasurface designed based on PBP. Such a superposition of Laguerre–Gaussian modes forms a double-ring-shaped cylindrical vector beam. Additionally, the local polarization orientation can be manipulated by changing the polarization angle of the input field. Our experimental results agree well with the theoretical expectation. We believe that PBP provides an extra choice to manipulate the phase and polarization of optical field. © 2017 Elsevier GmbH
语种：
英文
展开
Mesh saliency detection via double absorbing Markov chain in feature space
作者：
Liu, Xiuping;Tao, Pingping;Cao, Junjie* ;Chen, He;Zou, Changqing
期刊：
VISUAL COMPUTER ,2016年32(9):1121-1132 ISSN：0178-2789
通讯作者：
Cao, Junjie
作者机构：
[Liu, Xiuping; Cao, Junjie; Chen, He; Tao, Pingping] Dalian Univ Technol, Sch Math Sci, Dalian 116024, Peoples R China.;[Zou, Changqing] Hengyang Normal Univ, Coll Comp Sci & Technol, Hengyang 421000, Peoples R China.;[Zou, Changqing] Simon Fraser Univ, Sch Comp Sci, Burnaby, BC V5A 1S6, Canada.
通讯机构：
[Cao, Junjie] D;Dalian Univ Technol, Sch Math Sci, Dalian 116024, Peoples R China.
关键词：
Mesh saliency;Absorbing Markov chain;Feature space;Foreground cues
摘要：
We propose a mesh saliency detection approach using absorbing Markov chain. Unlike most of the existing methods based on some center-surround operator, our method employs feature variance to obtain insignificant regions and considers both background and foreground cues. Firstly, we partition an input mesh into a set of segments using Ncuts algorithm and then each segment is over segmented into patches based on Zernike coefficients. Afterwards, some background patches are selected by computing feature variance within the segments. Secondly, the absorbed time of each node is calculated via absorbing Markov chain with the background patches as absorbing nodes, which gives a preliminary saliency measure. Thirdly, a refined saliency result is generated in a similar way but with foreground nodes extracted from the preliminary saliency map as absorbing nodes, which inhibits the background and efficiently enhances salient foreground regions. Finally, a Laplacian-based smoothing procedure is utilized to spread the patch saliency to each vertex. Experimental results demonstrate that our scheme performs competitively against the state-of-the-art approaches.
语种：
英文
展开
Kinetics, equilibrium, and thermodynamics investigation on the adsorption of lead(II) by coal-based activated carbon
作者：
Yi, Zhengji;Yao, Jun* ;Zhu, Mijia;Chen, Huilun;Wang, Fei;...
期刊：
SpringerPlus ,2016年5(1):1-12 ISSN：2193-1801
通讯作者：
Yao, Jun
作者机构：
[Liu, Xing; Yi, Zhengji] Hengyang Normal Univ, Dept Chem & Mat Sci, Coll Hunan Prov, Key Lab Funct Organometall Mat, Hengyang 421008, Peoples R China.;[Yao, Jun; Wang, Fei; Chen, Huilun; Yi, Zhengji; Zhu, Mijia] Univ Sci & Technol Beijing, Sch Civil & Environm Engn, Xueyuan Rd 30, Beijing 100083, Peoples R China.;[Yao, Jun; Wang, Fei; Chen, Huilun; Yi, Zhengji; Zhu, Mijia] Univ Sci & Technol Beijing, Natl Int Cooperat Base Environm & Energy, Xueyuan Rd 30, Beijing 100083, Peoples R China.;[Yao, Jun] China Univ Geosci, Sinohungarian Joint Lab Environm Sci & Hlth, Sch Water Resource & Environm Engn, Beijing 100083, Peoples R China.
通讯机构：
[Yao, Jun] U;[Yao, Jun] C;Univ Sci & Technol Beijing, Sch Civil & Environm Engn, Xueyuan Rd 30, Beijing 100083, Peoples R China.;Univ Sci & Technol Beijing, Natl Int Cooperat Base Environm & Energy, Xueyuan Rd 30, Beijing 100083, Peoples R China.;China Univ Geosci, Sinohungarian Joint Lab Environm Sci & Hlth, Sch Water Resource & Environm Engn, Beijing 100083, Peoples R China.
关键词：
Adsorption;Coal-based activated carbon (CBAC);Isotherm;Kinetics;Pb(II);Thermodynamics
摘要：
The goal of this research is to investigate the feasibility of using activated coal-based activated carbon (CBAC) to adsorb Pb(II) from aqueous solutions through batch tests. Effects of contact time, pH, temperature and initial Pb(II) concentration on the Pb(II) adsorption were examined. The Pb(II) adsorption is strongly dependent on pH, but insensitive to temperature. The best pH for Pb(II) removal is in the range of 5.0–5.5 with more than 90 % of Pb(II) removed. The equilibrium time was found to be 60 min and the adsorption data followed the pseudo-second-order kinetics. Isotherm data followed Langmuir isotherm model with a maximum adsorption capacity of 162.33 mg/g. The adsorption was exothermic and spontaneous in nature. The Fourier transform infrared spectroscopy and scanning electron microscopy analysis suggested that CBAC possessed a porous structure and was rich in carboxyl and hydroxyl groups on its surface, which might play a major role in Pb(II) adsorption. These findings indicated that CBAC has great potential as an alternative adsorbent for Pb(II) removal. © 2016, The Author(s).
语种：
英文
展开
Stabilized enzyme immobilization on micron-size PSt-GMA microspheres: Different methods to improve the carriers' surface biocompatibility
作者：
Peng, Gang;Hou, Xiaohui;Liu, Bailing* ;Chen, Hualin;Luo, Rong
期刊：
RSC Advances ,2016年6(94):91431-91439 ISSN：2046-2069
通讯作者：
Liu, Bailing
作者机构：
[Peng, Gang] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Peng, Gang] Hengyang Normal Univ, Hunan Prov Coll, Key Lab Funct Organomet Mat, Hengyang 421008, Peoples R China.;[Chen, Hualin; Peng, Gang; Liu, Bailing; Luo, Rong; Hou, Xiaohui] Chinese Acad Sci, Chengdu Inst Organ Chem, Renminnan Rd 9, Chengdu 610041, Sichuan, Peoples R China.
通讯机构：
[Liu, Bailing] C;Chinese Acad Sci, Chengdu Inst Organ Chem, Renminnan Rd 9, Chengdu 610041, Sichuan, Peoples R China.
摘要：
Stabilized immobilization of biomacromolecules on carriers with appropriate orientation and minimum conformational changes is very important in the biochemical and biomedical fields. In this study, PSt-GMA(polystyrene-glycidyl methacrylate) microspheres were utilized as the carriers of immobilizing glucose oxidase (GOD). To improve the carrier's biocompatibility, anionic sulfonate groups and different length of spacer arms were introduced onto the microspheres' surface. The effect of carrier surface properties on the activity and stability of immobilized enzymes was investigated. The results show that the introduction of sulfonate groups and spacer arms could effectively reduce the unspecific adsorption of enzymes and improve their stabilities. Besides, with the increase of the length of spacer arms, both the immobilization amount and stabilities of immobilized GOD could be increased under different experimental conditions. ©2016 The Royal Society of Chemistry.
语种：
英文
展开
The surface characteristics of chitosan modified PSt-GMA microspheres influenced the interactions and properties of immobilized pepsin
作者：
Peng, Gang;Meng, Xu;Wang, Bin;Liu, Bailing* ;Chen, Hualin
期刊：
JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY ,2015年52(1):20-29 ISSN：1060-1325
通讯作者：
Liu, Bailing
作者机构：
[Peng, Gang] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Peng, Gang] Hengyang Normal Univ, Key Lab Funct Organometall Mat, Hunan Prov Coll, Hengyang 421008, Peoples R China.;[Chen, Hualin; Peng, Gang; Meng, Xu; Liu, Bailing; Wang, Bin] Chinese Acad Sci, Chengdu Inst Organ Chem, Chengdu 610041, Sichuan, Peoples R China.;[Liu, Bailing] Chinese Acad Sci, Chengdu Inst Organ Chem, Renminnan Rd 9, Chengdu 610041, Sichuan, Peoples R China.
通讯机构：
[Liu, Bailing] C;Chinese Acad Sci, Chengdu Inst Organ Chem, Renminnan Rd 9, Chengdu 610041, Sichuan, Peoples R China.
关键词：
pepsin immobilization;PSt-GMA microsphere;stabilization;enzymatic activity;Chitosan modified microsphere
摘要：
The surface characteristics of carriers outstandingly influence the application of immobilized enzymes. Because of its biocompatible and multi-functional groups, chitosan was introduced into poly(styrene-co-glycidyl methacrylate) (PSt-GMA) microspheres with/without spacer-arms. Pepsin was immobilized onto these microspheres by a simple and mild process, and then its enzymatic activity was evaluated. As for the different modified microspheres, the interactions between the carrier and enzyme molecules would be different, influencing the immobilized system. The experimental results suggested that the optimal pH for immobilized enzyme was close to the optimal reaction pH of free enzyme. It was also found that the Freundlich model fit the immobilized process better than the Langmuir model. In addition, pepsin immobilized onto chitosan modified microspheres (CMM, M3-M4) possessed a higher affinity to substrate, hemoglobin. Compared to free pepsin, the optimal reaction temperature of immobilized pepsin onto modified microspheres (M2-M4) shifted toward higher temperature. Furthermore, the thermal and storage stabilities of pepsin after immobilization were enhanced, particularly for pepsin immobilizing onto CMMs. The pepsin linked onto M3/M4 still retained approximately 70% of enzymatic activity after storing 50 days, compared to below 20% for free pepsin. In a word, CMMs provide more interactions and biocompatible surface for immobilized enzymes. © 2015 Copyright © Taylor & Francis Group, LLC.
语种：
英文
展开
Successive iteration and positive solutions for boundary value problem of nonlinear fractional q-difference equation
作者：
Liu Yang;Haibo Chen;Liping Luo;Zhenguo Luo
期刊：
Journal of Applied Mathematics and Computing ,2013年42(1-2):89-102 ISSN：1598-5865
通讯作者：
Yang, L.(yangliu19731974@yahoo.com.cn)
作者机构：
[Liu Yang; Liping Luo; Zhenguo Luo] Department of Mathematics and Computing Sciences, Hengyang Normal University, Hengyang, People’s Republic of China;[Haibo Chen] Department of Mathematics, Central South University, Changsha, People’s Republic of China
通讯机构：
[Liu Yang] D;Department of Mathematics and Computing Sciences, Hengyang Normal University, Hengyang, People’s Republic of China
关键词：
Existence and uniqueness;Iterative schemes;Positive solution;Q-difference equation;Successive iteration;Boundary value problems;Difference equations
摘要：
In this paper, we investigate the positive solutions for a class of nonlinear q-fractional boundary value problem. We not only obtain the existence and uniqueness of positive solutions, but also establish the iterative schemes for approximating the solutions, which is benefit for computation and application. © 2012 Korean Society for Computational and Applied Mathematics.
语种：
英文
展开
Infinitely many homoclinic solutions for some second order Hamiltonian systems
作者：
Yang, Liu;Chen, Haibo* ;Sun, Juntao
期刊：
NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS ,2011年74(17):6459-6468 ISSN：0362-546X
通讯作者：
Chen, Haibo
作者机构：
[Chen, Haibo; Yang, Liu; Sun, Juntao] Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.;[Yang, Liu] Hengyang Normal Univ, Dept Math & Comp Sci, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Chen, Haibo] C;Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.
关键词：
Critical points;Hamiltonian systems;Homoclinic solutions;Second orders;Fountains;Hamiltonians
摘要：
In this paper, we investigate the existence of infinitely many homoclinic solutions for a class of second order Hamiltonian systems. By using fountain theorem due to Zou, we obtain two new criteria for guaranteeing that second order Hamiltonian systems have infinitely many homoclinic solutions. Recent results in the literature are generalized and significantly improved. © 2011 Elsevier Ltd. All rights reserved.
语种：
英文
展开
The multiplicity of solutions for fourth-order equations generated from a boundary condition
作者：
Yang, Liu;Chen, Haibo* ;Yang, Xiaoxia
期刊：
Applied Mathematics Letters ,2011年24(9):1599-1603 ISSN：0893-9659
通讯作者：
Chen, Haibo
作者机构：
[Chen, Haibo; Yang, Liu; Yang, Xiaoxia] Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.;[Yang, Liu] Hengyang Normal Univ, Dept Math & Computat Sci, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Chen, Haibo] C;Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.
关键词：
Fourth-order differential systems;Solution generated from a boundary condition;Critical point
摘要：
In this work, we investigate a boundary value problem for fourth-order differential systems. By using variational methods and a three-critical-point theorem, we establish sufficient conditions under which such a system possesses two solutions generated from a boundary condition. To illustrate the main results, an example is given.
语种：
英文
展开
Nonlocal Boundary Value Problem for Impulsive Differential Equations of Fractional Order
作者：
Yang, Liu* ;Chen, Haibo
期刊：
Advances in Difference Equations ,2011年2011(1):1-16 ISSN：1687-1839
通讯作者：
Yang, Liu
作者机构：
[Chen, Haibo; Yang, Liu] Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.;[Yang, Liu] Hengyang Normal Univ, Dept Math & Computat Sci, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Yang, Liu] C;Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.
关键词：
Positive Constant;Fractional Order;Fractional Derivative;Fractional Calculus;Fractional Differential Equation
摘要：
We study a nonlocal boundary value problem of impulsive fractional differential equations. By means of a fixed point theorem due to O'Regan, we establish sufficient conditions for the existence of at least one solution of the problem. For the illustration of the main result, an example is given.
语种：
英文
展开
Existence and Multiplicity of Periodic Solutions Generated by Impulses
作者：
Yang, Liu;Chen, Haibo*
期刊：
Abstract and Applied Analysis ,2011年2011:1-15 ISSN：1085-3375
通讯作者：
Chen, Haibo
作者机构：
[Chen, Haibo; Yang, Liu] Cent S Univ, Dept Math, Changsha 421008, Hunan, Peoples R China.;[Yang, Liu] Hengyang Normal Univ, Dept Math & Comp Sci, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Chen, Haibo] C;Cent S Univ, Dept Math, Changsha 421008, Hunan, Peoples R China.
关键词：
We investigate the existence and multiplicity of periodic solutions for a class of second-order differential systems with impulses. By using variational methods and critical point theory;we obtain such a system possesses at least one nonzero;two nonzero;or infinitely many periodic solutions generated by impulses under different conditions;respectively. Recent results in the literature are generalized and significantly improved. Published: 2011 First available in Project Euclid: 12 August 2011 zbMATH: 1253.34046 MathSciNet: MR2800077 Digital Object Identifier: 10.1155/2011/310957
摘要：
We investigate the existence and multiplicity of periodic solutions for a class of second-order differential systems with impulses. By using variational methods and critical point theory, we obtain such a system possesses at least one nonzero, two nonzero, or infinitely many periodic solutions generated by impulses under different conditions, respectively. Recent results in the literature are generalized and significantly improved.
语种：
英文
展开
Variational methods to fourth-order impulsive differential equations
作者：
Juntao Sun;Haibo Chen;Liu Yang
期刊：
Journal of Applied Mathematics and Computing ,2011年35(1-2):323-340 ISSN：1598-5865
通讯作者：
Sun, J.(sunjuntao2008@163.com)
作者机构：
[Liu Yang; Haibo Chen; Juntao Sun] Department of Mathematics, Central South University, Changsha, Hunan 410075, China;[Liu Yang] Department of Mathematics, Hengyang Normal University, Hengyang, Hunan 421008, China
通讯机构：
[Juntao Sun] D;Department of Mathematics, Central South University, Changsha, People’s Republic of China
关键词：
Abrupt change;Critical points;Critical-point theory;Dynamical behaviors;Evolution process;Fourth-order;Impulsive differential equation;Mathematical descriptions;Multiplicity of solutions;Nontrivial solution;Variational methods;Boundary value problems;Dynamical systems
摘要：
Many dynamical systems have impulsive dynamical behaviors due to abrupt changes at certain instants during the evolution process. The mathematical description of these phenomena leads to impulsive differential equations. In this paper, we study the existence and multiplicity of solutions for fourth-order impulsive differential equations. By using the variational methods and critical point theory, we give some new criteria to guarantee that the impulsive problem has at least one nontrivial solution, infinitely many distinct solutions under some different conditions, respectively. Some examples are given in this paper to illustrate the feasibilities of our main results. © 2009 Korean Society for Computational and Applied Mathematics.
语种：
英文
展开
Positive solutions of asymptotically linear Schrödinger–Poisson systems with a radial potential vanishing at infinity
作者：
Sun, Juntao* ;Chen, Haibo;Yang, Liu
期刊：
NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS ,2011年74(2):413-423 ISSN：0362-546X
通讯作者：
Sun, Juntao
作者机构：
[Chen, Haibo; Sun, Juntao; Yang, Liu] Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.;[Yang, Liu] Hengyang Normal Univ, Dept Math, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Sun, Juntao] C;Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.
关键词：
Asymptotically linear;Non-Linearity;Nonlinear SchrdingerPoisson system;Positive solution;Vanishing potential;Variational methods;Asymptotic analysis
摘要：
In this paper, we study the SchrdingerPoisson system -Δu+V(x) u+λφ(x)u=K(x)f(u),inR3,-Δφ=u2,u>0,inR3, and prove the existence of positive solutions for system (SP) when the nonlinearity f has growth at most linear for λ small, allowing the potential V(x) to vanish at infinity. In addition, also we obtain the nonexistence of a nontrivial positive solution for λ<14. © 2010 Elsevier Ltd. All rights reserved.
语种：
英文
展开
Existence and multiplicity of solutions to even order ordinary differential equations via variational methods
作者：
Yang, Liu* ;Chen, Haibo
期刊：
NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS ,2010年72(7-8):3422-3428 ISSN：0362-546X
通讯作者：
Yang, Liu
作者机构：
[Chen, Haibo; Yang, Liu] Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.;[Yang, Liu] Hengyang Normal Univ, Dept Math, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Yang, Liu] C;Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.
关键词：
Critical point theory;Multiplicity of solutions;Non-Linearity;Nontrivial solution;Positive definite kernels;Projective operator;Two-point boundary value problem;Variational methods;Control nonlinearities;Dynamical systems;Equations of state;Integral equations;Mathematical operators;Nonlinear equations;Ordinary differential equations
摘要：
In this paper, we study the existence and multiplicity of solutions for two-point boundary value problems for even order ordinary differential equation. By using the critical point theory and the property of projective operator, we establish some conditions on the nonlinearity which guarantee that the nonlinear Hammerstein integral equation with quasi-positive definite kernel has at least one solution, two nontrivial solutions and finite pairs of solutions, respectively. As an application, we get the corresponding results for two-point boundary value problems for even order ordinary differential equation. Moreover, an example is presented to illustrate our main results. © 2009 Elsevier Ltd. All rights reserved.
语种：
英文
展开
The existence and multiplicity of solutions for an impulsive differential equation with two parameters via a variational method
作者：
Sun, Juntao* ;Chen, Haibo;Yang, Liu
期刊：
NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS ,2010年73(2):440-449 ISSN：0362-546X
通讯作者：
Sun, Juntao
作者机构：
[Chen, Haibo; Sun, Juntao; Yang, Liu] Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.;[Yang, Liu] Henyang Normal Univ, Dept Math, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Sun, Juntao] C;Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.
关键词：
Critical points;Impulsive differential equation;Local linking;Variational method;Variational methods;Equations of state;Ordinary differential equations;Boundary conditions
摘要：
In this paper, we study the existence and multiplicity of classical solutions for a second-order impulsive differential equation with periodic boundary conditions. By using a variational method and critical point theory, we give some new criteria to guarantee that the impulsive problem has at least one solution, two solutions and infinitely many solutions when the parameter pair (c,λ) lies in different intervals, respectively. Some examples are given in this paper to illustrate the main results. © 2010 Elsevier Ltd. All rights reserved.
语种：
英文
展开
Unique positive solutions for fractional differential equation boundary value problems
作者：
Yang, Liu;Chen, Haibo*
期刊：
Applied Mathematics Letters ,2010年23(9):1095-1098 ISSN：0893-9659
通讯作者：
Chen, Haibo
作者机构：
[Chen, Haibo; Yang, Liu] Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.;[Yang, Liu] Hengyang Normal Univ, Dept Math, Hengyang 421008, Hunan, Peoples R China.
通讯机构：
[Chen, Haibo] C;Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.
关键词：
Boundary value problem;Fractional differential equation;Iterative schemes;Positive solution;Riemann-Liouville differentiation
摘要：
In this work, we consider the uniqueness of positive solutions for fractional differential equation boundary value problems. Our results can not only guarantee the existence of a unique positive solution, but also be applied to construct an iterative scheme for approximating it. © 2010 Elsevier Ltd. All rights reserved.
语种：
英文
展开
