摘要：
A graphene oxide (GO) film coated glassy carbon electrode (GCE) was fabricated for sensitive determination of 4-nitrophenol (4-NP). The GO-based sensor was characterized by scanning electron microscope, atomic force microscopy and electrochemical impedance spectroscopy. The electrochemical behaviors of 4-NP at the GO-film coated GCE were investigated in detail. In 0.1 M acetate buffer with a pH of 4.8, 4-NP yields a very sensitive and well-defined reduction peak at the GO-modified GCE. It is found that the GO film exhibits obvious electrocatalytic activity toward the reduction of 4-NP since it not only increases the reduction peak current but also lowers the reduction overpotential. Based on this, an electrochemical method was proposed for the direct determination of 4-NP. Various kinetic parameters such as transfer electron number, transfer proton number and standard heterogeneous rate constant were calculated, and various experimental parameters were also optimized. Under the optimal conditions, the reduction peak current varies linearly with the concentration of 4-NP ranging from 0.1 to 120 mu M, and the detection limit is 0.02 mu M at the signal noise ratio of 3. Moreover, the fabricated sensor presented high selectivity and long-term stability. This electrochemical sensor was further applied to determine 4-NP in real water samples, and it showed great promise for simple, sensitive, and quantitative detection of 4-NP. (C) 2011 Elsevier B.V. All rights reserved.
期刊：
Computer Vision and Image Understanding,2015年150:109-125 ISSN：1077-3142
通讯作者：
Peng, Xiaojiang(xiaojiang.peng@inria.fr)
作者机构：
[Peng, Xiaojiang] College of Computer Science and Technology, Hengyang Normal University, Hengyang, China;[Peng, Xiaojiang] LEAR Team, INRIA, Grenoble, France;[Wang, Limin; Wang, Xingxing; Qiao, Yu] Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China;Computer Vision Lab, ETH Zurich, Zurich, Switzerland
通讯机构：
[Peng, Xiaojiang] Hengyang Normal Univ, Coll Comp Sci & Technol, Hengyang, Peoples R China.;[Peng, Xiaojiang] Chinese Acad Sci, Shenzhen Inst Adv Technol, Shenzhen, Peoples R China.;[Peng, Xiaojiang] INRIA, LEAR Team, Grenoble, France.
关键词：
Action recognition;Bag of visual words;Fusion methods;Feature encoding
摘要：
Video based action recognition is one of the important and challenging problems in computer vision research. Bag of visual words model (BoVW) with local features has been very popular for a long time and obtained the state-of-the-art performance on several realistic datasets, such as the HMDB51, UCF50, and UCF101. BoVW is a general pipeline to construct a global representation from local features, which is mainly composed of five steps; (i) feature extraction, (ii) feature pre-processing, (iii) codebook generation, (iv) feature encoding, and (v) pooling and normalization. Although many efforts have been made in each step independently in different scenarios, their effects on action recognition are still unknown. Meanwhile, video data exhibits different views of visual patterns , such as static appearance and motion dynamics. Multiple descriptors are usually extracted to represent these different views. Fusing these descriptors is crucial for boosting the final performance of an action recognition system. This paper aims to provide a comprehensive study of all steps in BoVW and different fusion methods, and uncover some good practices to produce a state-of-the-art action recognition system. Specifically, we explore two kinds of local features, ten kinds of encoding methods, eight kinds of pooling and normalization strategies, and three kinds of fusion methods. We conclude that every step is crucial for contributing to the final recognition rate and improper choice in one of the steps may counteract the performance improvement of other steps. Furthermore, based on our comprehensive study, we propose a simple yet effective representation, called hybrid supervector, by exploring the complementarity of different BoVW frameworks with improved dense trajectories. Using this representation, we obtain impressive results on the three challenging datasets; HMDB51 (61.9%), UCF50 (92.3%), and UCF101 (87.9%).
摘要：
A unique 4-fold interpenetrated (10,3)-b copper(II) framework exhibits reversible dehydration and rehydration in a single-crystal-to-single-crystal (SC-SC) process, and the dehydrated material can encapsulate CH(3)OH molecules, again in a SC-SC fashion, and shows selective adsorption of H(2) and CO(2) over N(2).
期刊：
Biosensors and Bioelectronics,2014年54:468-475 ISSN：0956-5663
通讯作者：
Qian, D
作者机构：
[Qian, Dong; Li, Junhua] State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;[Deng, Miao; Liu, Youcai; Tan, Gongrong; Qian, Dong; Jiang, Jianbo; Peng, Sanjun; Li, Junhua; Liu, Jinlong] College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China;[Li, Junhua; Feng, Yonglan] Department of Chemistry and Material Science, Hengyang Normal University, Hengyang 421008, China
通讯机构：
[Qian, Dong] Cent S Univ, Coll Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.
摘要：
Well-dispersed Pd nanoparticles were facilely anchored on graphene oxide (Pd/GO) via a one-pot chemical reduction of the Pd2+ precursor without any surfactants and templates. The morphology and composition of the Pd/GO nanocomposite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FUR) and energy dispersive analysis of X-ray (EDX). The stepwise fabrication process of the Pd/GO modified electrode and its electrochemical sensing performance towards paracetamol was evaluated using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The experimental results indicate that the as-synthesized Pd nanoparticles are relatively uniform in size (5-10 nm) without large aggregation and uniformly distributed in the carbon matrix with the overall Pd content of 28.77 wt% in Pd/GO. Compared with the GO modified electrode, the Pd/GO modified electrode shows a better electrocatalytic activity to the oxidation of paracetamol with lower oxidation potential and larger peak current, so the Pd/GO nanocomposite can be used as an enhanced sensing platform for the electrochemical determination of paracetamol. The kinetic parameters of the paracetamol electro-oxidation at Pd/GO electrode were studied in detail, and the determination conditions were optimized. Under the optimal conditions, the oxidation peak current is linear to the paracetamol concentration in the ranges of 0.005-0.5 mu M and 0.5-80.0 mu M with a detection limit of 2.2 nM. Based on the high sensitivity and good selectivity of the Pd/GO modified electrode, the proposed method was successfully applied to the determination of paracetamol in commercial tablets and human urines, and the satisfactory results confirm the applicability of this sensor in practical analysis. (C) 2013 Elsevier B.V. All rights reserved.
摘要：
A new kind of nanocomposite based on silver nanoparticles (AgNPs)/graphene oxide (GO) was conveniently achieved through a green and low-cost synthesis approach using glucose as a reducing and stabilizing agent, and the synthetic procedure can be easily used for the construction of a disposable electrochemical sensor on glassy carbon electrode (GCE). The nanocomposite was detailedly characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS). The experimental results demonstrated that the nanocomposite possessed the specific features of both silver nanoparticles and graphene, and the intrinsic high specific area and the fast electron transfer rate ascribed to the nanohybrid structure could improve its electrocatalytic performance greatly. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed to evaluate the electrochemical properties of AgNPs/GO/GCE towards tryptophan, and the AgNPs/GO film exhibited a distinctly higher activity for the electro-oxidation of tryptophan than GO film with tenfold enhancement of peak current. The oxidation mechanism and the kinetic parameters were investigated, and analysis operation conditions were optimized. Under the selected experimental conditions, the oxidation peak currents were proportional to tryptophan concentrations over the range of 0.01 mu M to 50.0 mu M and 50.0 mu M to 800.0 mu M, respectively. The detection limit was 2.0 nM (S/N=3). Moreover, the proposed method is free of interference from tyrosine and other coexisting species. The resulting sensor displays excellent repeatability and long-term stability; finally it was successfully applied to detect tryptophan in real samples with good recoveries, ranging from 99.0% to 103.0%. (C) 2012 Elsevier B.V. All rights reserved.
作者机构：
[Qiu, Cheng-Wei; Mei, Shengtao; Mehmood, M.Q.; Siew, S.Y.; Zhang, Lei; Zhang, Tianhang; Danner, Aaron; Hussain, Sajid; Ling, Xiaohui] Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, Singapore;[Qiu, Cheng-Wei; Mei, Shengtao] Graduate School for Integrative Sciences and Engineering, National University of Singapore, Centre for Life Sciences (CeLS), #05-01, 28 Medical Drive, Singapore, Singapore;[Liu, Hong; Huang, Kun; Teng, Jinghua] Institute of Materials Research, Engineering Agency for Science Technology and Research (ASTAR) Innovis, #08-03 2 Fusionopolis Way, Singapore, Singapore;[Ling, Xiaohui] College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang, China;[Zhang, Shuang] School of Physics and Astronomy, University of Birmingham, Birmingham, United Kingdom
通讯机构：
[Qiu, Cheng-Wei] Natl Univ Singapore, Dept Elect & Comp Engn, 4 Engn Dr 3, Singapore 117583, Singapore.;[Qiu, Cheng-Wei] Natl Univ Singapore, Ctr Life Sci CeLS, Grad Sch Integrat Sci & Engn, 05-01,28 Med Dr, Singapore 117456, Singapore.
作者机构：
[Zhou, Xinxing; Liu, Yachao; Luo, Hailu; Shu, Weixing; Ling, Xiaohui; Wen, Shuangchun; Fan, Dianyuan; Chen, Shizhen] Laboratory for Spin Photonics, School of Physics and Electronics, Hunan University, Changsha, 410082, China;[Ling, Xiaohui; Yi, Xunong; Fan, Dianyuan] SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology, Key Laboratory of Optoelectronic Devices, Systems of Ministry of Education and Guangdong Province, Shenzhen University, Shenzhen, 518060, China;[Ling, Xiaohui] Department of Physics and Electronic Information Science, Hengyang Normal University, Hengyang, 421002, China
关键词：
geometric phase;metamaterial;photonic spin Hall effect
摘要：
The photonic spin Hall effect (SHE) in the reflection and refraction at an interface is very weak because of the weak spin-orbit interaction. Here, we report the observation of a giant photonic SHE in a dielectric-based metamaterial. The metamaterial is structured to create a coordinate-dependent, geometric Pancharatnam-Berry phase that results in an SHE with a spin-dependent splitting in momentum space. It is unlike the SHE that occurs in real space in the reflection and refraction at an interface,which results from the momentum-dependent gradient of the geometric Rytov-Vladimirskii-Berry phase. We theorize a unified description of the photonic SHE based on the two types of geometric phase gradient, and we experimentally measure the giant spin-dependent shift of the beam centroid produced by the metamaterial at a visible wavelength. Our results suggest that the structured metamaterial offers a potential method of manipulating spin-polarized photons and the orbital angular momentum of light and thus enables applications in spin-controlled nanophotonics.
作者机构：
[Deng, Peihong] Department of Chemistry and Material Science, Hengyang Normal University, Hengyang 421008, PR China. Electronic address: dph1975@163.com;[Xu, Zhifeng; Kuang, Yunfei] Department of Chemistry and Material Science, Hengyang Normal University, Hengyang 421008, PR China
通讯机构：
[Deng, Peihong] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
关键词：
spin Hall effect of light;spin Hall shift;geometric phase;weak measurements
摘要：
The spin Hall effect (SHE) of light, as an analogue of the SHE in electronic systems, is a promising candidate for investigating the SHE in semiconductor spintronics/valleytronics, high-energy physics and condensed matter physics, owing to their similar topological nature in the spin-orbit interaction. The SHE of light exhibits unique potential for exploring the physical properties of nanostructures, such as determining the optical thickness, and the material properties of metallic and magnetic thin films and even atomically thin two-dimensional materials. More importantly, it opens a possible pathway for controlling the spin states of photons and developing next-generation photonic spin Hall devices as a fundamental constituent of the emerging spinoptics. In this review, based on the viewpoint of the geometric phase gradient, we give a detailed presentation of the recent advances in the SHE of light and its applications in precision metrology and future spin-based photonics.
期刊：
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY,2010年10(8):4868-4874 ISSN：1533-4880
通讯作者：
Yuan, Yali
作者机构：
[Ding, Jianqiang] Zhenhai Center for Disease Control and Prevention, Ningbo 315200, China;[Xu, Jinsheng] Department of Chemistry and Materials Science, Hengyang Normal University, Hengyang 421008, China;[Deng, Jian; Yuan, Yali] School of Chemistry and Chemical Engineering, University of South China, Hengyang 421001, China;[Guo, Jianbo] School of Public Health, University of South China, Hengyang 421001, China
通讯机构：
[Yuan, Yali] Univ S China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.
会议主办单位：
(1) School of Chemistry and Chemical Engineering, University of South China, Hengyang 421001, China; (2) Zhenhai Center for Disease Control and Prevention, Ningbo 315200, China; (3) Department of Chemistry and Materials Science, Hengyang Normal University, Hengyang 421008, China; (4) School of Public Health, University of South China, Hengyang 421001, China
期刊：
GREEN CHEMISTRY,2012年14(5):1268-1271 ISSN：1463-9262
通讯作者：
Wang, DP
作者机构：
[Yu, Jiangxi; Li, Junhua; Zhang, Fuxing; Wang, Deping; Kuang, Daizhi] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.;[Yu, Jiangxi; Li, Junhua; Zhang, Fuxing; Kuang, Daizhi] Hengyang Normal Univ, Coll Hunan Prov, Key Lab Funct Organometall Mat, Hengyang 421008, Peoples R China.
通讯机构：
[Wang, Deping] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
摘要：
6,7-Dihydroquinolin-8(5H)-one oxime (L3) was found to serve as a superior ligand for the CuI-catalyzed N-arylation of imidazoles with aryl iodides, bromides, and electron-deficient chlorides in water. Moreover, the CuI/L3 catalyst system enabled the coupling reactions to take place smoothly with high yields under a low catalyst loading (0.1-1 mol% CuI and 0.2-2 mol% L3).
摘要：
A highly sensitive and mercury-free method for determination of bisphenol A (BPA) was established using a glassy carbon electrode that was modified with carboxylated multi-walled carbon nanotubes. A sensitive oxidation peak is found at 550 mV in linear sweep voltammograms at pH 7. Based on this finding, trace levels of bisphenol A can be determined over a concentration range that is linear from 10 nM to 104 nM, the correlation coefficient being 0.9983, and the detection limit (S/N = 3) being 5.0 nM. The method was successfully applied to the determination of BPA in food package. A new electrochemical method was developed for the determination of bisphenol A based on carboxylated multi-walled carbon nanotubes modified electrode.
作者：
Xu, Zhifeng;Uddin, Khan Mohammad Ahsan;Kamra, Tripta;Schnadt, Joachim;Ye, Lei
期刊：
ACS Applied Materials and Interfaces,2014年6(3):1406-1414 ISSN：1944-8244
通讯作者：
Ye, L
作者机构：
[Kamra, Tripta; Xu, Zhifeng; Ye, Lei; Uddin, Khan Mohammad Ahsan] Division of Pure and Applied Biochemistry, Lund University, Box 124, 221 00 Lund, Sweden;[Kamra, Tripta; Schnadt, Joachim] Division of Synchrotron Radiation Research, Lund University, Box 118, 221 00 Lund, Sweden;[Xu, Zhifeng] Key Laboratory of Functional Organometallic Materials, College of Hunan Province, Hengyang, Hunan 421008, China;[Xu, Zhifeng] Department of Chemistry and Material Science, Hengyang Normal University, Hengyang, Hunan 421008, China
通讯机构：
[Ye, Lei] Lund Univ, Div Pure & Appl Biochem, Box 124, S-22100 Lund, Sweden.
关键词：
Electronic band structure;Graphene;Doping;Density-functional theory
摘要：
A pathway to open the band gap of graphene by p-n codoping is presented according to the first principles study. Two models are used: Lithium adsorbed on Boron-doped graphene (BC) and Boron-Nitrogen (B/N) codoping into graphene. The stability of Lithium adsorbed on BC is firstly analyzed, showing that the hollow site is the most stable configuration, and there is no energy barrier from some metastable configurations to a stable one. After the p-n codoping, the electronic structures of graphene are modulated to open a band gap with width from 0.0 eV to 0.49 eV, depending on the codoping configurations. The intrinsic physical mechanism responsible for the gap opening is the combination of the Boron atom acting as hole doping and Nitrogen (Lithium) as electron doping. (C) 2011 Elsevier B.V. All rights reserved.
摘要：
Assembly reactions of 5-(isonicotinamido) isophthalic acid (H(2)INAIP) with Ln(2)O(3) or Ln(NO3)(3)center dot 6H(2)O together with NaOH in the presence of AgNO3 result in formation of two series of new 4d-4f heterometallic coordination polymers {[LnAg(INAIP)(2)]center dot 3H(2)O}(n)[Ln = Nd (1), Sm (2), Eu (3), Gd (4), Tb (5)] and {[LnAg(INAIP)(2)(H2O)]center dot xH(2)O}(n) [Ln = La (6), Pr (7), Nd (8), x = 0; Dy (9), Er (10), x = 1]. The results of single-crystal X-ray diffraction analysis indicate that 1-5 are isomorphous and have 2-fold interpenetrated 3D structure with 3-nodal net Point (Schlafli) symbol for net: (4.6(2))(4)(4(4).6(6).8(15).10(3)), while 6-10 are isostructural with similar non-interpenetrating 3D frameworks containing 2D lanthanide-carboxylate bilayers. The results indicate that the reaction conditions have great influence on the structure of the resulting complexes in this system. Furthermore, 3 and 5 show intense red and green fluorescent emissions, respectively, and the emission bands of Nd(III) were observed in the near IR region for 1. The magnetic properties of 1-5, 9 and 10 were investigated.
摘要：
Assembly reactions of pyridyl-and carboxylate-containing ligand 5-(isonicotinamido)isophthalic acid (H(2)INAIP) with corresponding metal salts result in formation of six new coordination polymers, namely {[Mn(INAIP)(DMF)]center dot 0.5DMF}(n) (1), {[Mn(INAIP)(H2O)(2)]center dot 4H(2)O}(n) (2), {[Co(INAIP)(H2O)]center dot 2H(2)O}(n) (3), {[Co(INAIP)(bpy)(0.5)]}(n) (4), {[Co(INAIP)(Him)(H2O)]center dot H2O}(n) (5), and {[Cu(INAIP)(Him)(H2O)]center dot H2O}(n) (6) (DMF N,N-dimethylformamide, bpy - 4,4'-bipyridine, Him imidazole). The results of single-crystal X-ray diffraction analysis indicate that 1 is a two-fold interpenetrated three-dimensional (3D) framework with sra topology, complexes 2, 5 and 6 have two-dimensional (2D) network structure with (6,3) topology, while 3 and 4 have infinite 2D bi-layer structure with different topologies. Complex 3 exhibits a 4-connected network with the Schlafli symbol (4(3).6(3)), and 4 displays a (4,5)-connected net with Schlafli symbol (4(3).5(2).6)(4(3).5(5).6(2)). The magnetic and adsorption properties of the complexes were investigated.
作者机构：
[Xia, Li-Xin] Department of Physics, Henan University of Science and Technology, Luoyang, 471003, China;[Zhang, Deng-Yu; Wang, Xin-Wen] Department of Physics and Electronic Information Science, Hengyang Normal University, Hengyang, 421008, China;[Wang, Zhi-Yong] National Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093, China;[Wang, Xin-Wen] Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing, 100875, China
通讯机构：
[Wang, Xin-Wen] Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.
关键词：
Multipartite entanglement;Quantum-information splitting;Asymmetric distribution
期刊：
Nonlinear Analysis, Theory, Methods and Applications,2010年73(2):440-449 ISSN：0362-546X
通讯作者：
Sun, JT
作者机构：
[Yang, Liu; Chen, Haibo; Sun, Juntao] Department of Mathematics, Central South University, Changsha, 410075 Hunan, China;[Yang, Liu] Department of Mathematics, Hengyang Normal University, Hengyang, 421008 Hunan, China
通讯机构：
[Sun, Juntao] Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.
关键词：
34B08;34B37;Impulsive differential equations;Boundary value problems;Critical points;Variational method;Local linking
摘要：
We report on a highly sensitive glucose biosensor that was fabricated from a composite made from mesoporous hydroxyapatite and mesoporous titanium dioxide which then were ultrasonically mixed with multi-walled carbon nanotubes to form a rough nanocomposite film. This film served as a platform to immobilize glucose oxidase onto a glassy carbon electrode. The morphological and electrochemical properties of the film were examined by scanning electron microscopy and electrochemical impedance spectroscopy. Cyclic voltammetry and chronoamperometry were used to characterize the electrochemical performances of the biosensor which exhibited excellent electrocatalytic activity to the oxidation of glucose. At an operating potential of 0.3 V and pH 6.8, the sensor displays a sensitivity of 57.0 μA mM−1 cm−2, a response time of <5 s, a linear dynamic range from 0.01 to 15.2 mM, a correlation coefficient of 0.9985, and a detection limit of 2 μM at an SNR of 3. No interferences are found for uric acid, ascorbic acid, dopamine and most carbohydrates. The sensor is stable and was successfully applied to the determination of glucose in real samples. Mesoporous hydroxyapatite, titanium dioxide and multi-walled carbon nanotubes were ultrasonically mixed to form a rough nanofilm, and a new glucose biosensor was fabricated based on this nanofilm. The biosensor had great bioelectrocatalytic activity to glucose oxidation, and it exhibited a high sensitivity, wide linear dynamic range and high selectivity for glucose determination.
作者机构：
[Ding, Chunxia] College of Science, Hunan Agricultural University, Changsha, China;[Deng, Peihong; Zeng, Rongying; Xu, Zhifeng] Department of Chemistry and Material Science, Hengyang Normal University, Hengyang, China;[Zeng, Rongying] College of Resource and Environment, Hunan Agricultural University, Changsha, China
通讯机构：
[Deng, Peihong] Hengyang Normal Univ, Dept Chem & Mat Sci, Hengyang 421008, Peoples R China.
