Direct synthesis of micro-coiled carbon fibers on graphite substrate using co-electrodeposition of nickel and sulfur as catalysts
WOS被引频次：11
SCI-E EI
作者：
Liu, Dengyou* ;Luo, Qimei;Wang, Huixian;Chen, Jinhua
期刊：
Materials and Design ,2009年30(3):649-652 ISSN：0261-3069
通讯作者：
Liu, Dengyou
作者机构：
[Luo, Qimei; Liu, Dengyou; Wang, Huixian] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Chen, Jinhua] Hunan Univ, Coll Chem & Chem Engn, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Liu, Dengyou] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
关键词：
Micro-coiled carbon fibers;Catalysts;Electrochemical deposition;Sulfur;Chemical vapour deposition;Scanning electron microscopy
摘要：
Micro-coiled carbon fibers were directly prepared on the graphite substrate using co-electrodeposition of nickel and sulfur as catalysts, in this paper. The diameter of coil and that of micro-coiled carbon fiber are about 800 nm and 400 nm, respectively. Compared with the current preparation methods of catalysts, electrochemical deposition is an effective, cheap and simple technique. Especially, this method is suitable for preparation of ally catalyst. The parameters of electrochemical deposition (deposition time and current density) have little influence on helix of growth and growth mechanism of carbon fibers. By adjusting the electrolyte solution, the amount of sulfur in catalyst are easily carried out, and it is found that sulfur content in catalyst plays an important role on morphological characteristics of carbon fibers. ©2008 Elsevier Ltd. All rights reserved.
语种：
英文
展开
Oxidant-Triggered C1-Benzylation of Isoquinoline by Iodine-Catalyzed Cross-Dehydrogenative-Coupling with Methylarenes
WOS被引频次：11
SCI-E
作者：
Shi, Xin;Zhang, Feng;Luo, Wen-Kun;Yang, Luo*
期刊：
Oxidant-Triggered C1-Benzylation of Isoquinoline by Iodine-Catalyzed Cross-Dehydrogenative-Coupling with Methylarenes ,2017年28(4):494-498 ISSN：0936-5214
通讯作者：
Yang, Luo
作者机构：
[Luo, Wen-Kun; Shi, Xin; Yang, Luo] Xiangtan Univ, Coll Chem, Minist Educ, Key Lab Environm Friendly Chem & Applicat, Xiangtan 411105, Hunan, Peoples R China.;[Zhang, Feng] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Yang, Luo] Xiangtan Univ, Coll Chem, Minist Educ, Key Lab Environm Friendly Chem & Applicat, Xiangtan 411105, Hunan, Peoples R China.
关键词：
Minisci reaction;benzylation;iodine;isoquinoline;isoquinolinone
摘要：
A practical iodine-catalyzed oxidative functionalization of isoquinolines with methylarenes is developed, which can be triggered by the selected oxidants to produce C1- or N-benzyl-substituted products selectively. This method utilizes readily available isoquinolines and methylarenes as starting materials and proceeds under metal-free conditions with broad substrate scope with respect to methylarenes, avoiding the usage of expensive metal catalysts and generation of halide and metal wastes. © Georg Thieme Verlag Stuttgart · New York-Synlett 2017.
语种：
英文
展开
Entanglement dynamics of a double two-photon Jaynes-Cummings model with Kerr-like medium
WOS被引频次：10
SCI-E EI CSCD
作者：
Ouyang Xi-Cheng;Fang Mao-Fa* ;Kang Guo-Dong;Deng Xiao-Juan;Huang Li-Yuan
期刊：
Chinese Physics B ,2010年19(3):55-60 ISSN：1674-1056
通讯作者：
Fang Mao-Fa
作者机构：
[Kang Guo-Dong; Ouyang Xi-Cheng; Deng Xiao-Juan; Fang Mao-Fa] Hunan Normal Univ, Coll Phys & Informat Sci, Changsha 410081, Hunan, Peoples R China.;[Ouyang Xi-Cheng] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Huang Li-Yuan] Changsha Univ, Dept Elect & Commun Engn, Changsha 410003, Hunan, Peoples R China.
通讯机构：
[Fang Mao-Fa] Hunan Normal Univ, Coll Phys & Informat Sci, Changsha 410081, Hunan, Peoples R China.
关键词：
entanglement sudden death;concurrence;two-photon Jaynes-Cummings model;Kerr-like medium
摘要：
In this paper, the entanglement dynamics of a double two-photon Jaynes-Cummings model with Kerr-like medium is investigated. It is shown that initial entanglement has an interesting subsequent time evolution, including the so-called entanglement sudden death effect. It is also shown analytically that the Kerr-like medium can repress entanglement sudden death and enhance the degree of atom-atom entanglement. A more interesting fact is that the Kerr effect is more obvious when each of the two cavities with have the Kerr-like medium than only one of them with the Kerr-like medium.
语种：
英文
展开
A hybrid of CoOOH nanorods with carbon nanotubes as a superior positive electrode material for supercapacitors
WOS被引频次：10
SCI-E EI
作者：
Zhu, Lei;Wu, Wenyi;Wang, Xiaowei;Wu, Xiongwei* ;Tang, Weiping;Wu, Yuping
期刊：
RSC Advances ,2014年4(103):59088-59093 ISSN：2046-2069
通讯作者：
Wu, Xiongwei
作者机构：
[Zhu, Lei; Wu, Xiongwei; Wu, Yuping] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Zhu, Lei; Wang, Xiaowei; Wu, Yuping; Wu, Wenyi] Fudan Univ, Key Lab Mol Catalysis & Innovat Mat, Dept Chem & Shanghai, NEML, Shanghai 200433, Peoples R China.;[Zhu, Lei; Tang, Weiping] Shanghai Acad Spaceflight Technol, Shanghai Inst Space Power Sources SISP, Shanghai 200233, Peoples R China.
通讯机构：
[Wu, Xiongwei] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
摘要：
A hybrid of CoOOH nanorods with conductive MWCNTs is successfully prepared. Due to the introduction of MWCNTs, the diameter of the CoOOH nanorods is smaller than that of pristine CoOOH nanorods. Because of the conductive nanostructure network and smaller diameter of the CoOOH nanorods, it exhibits high capacitance, good high-rate capability and excellent cycling performance as a positive electrode for supercapacitors in a 0.5 mol L<sup>-1</sup> KOH aqueous electrolyte. Its specific capacity is 312 F g<sup>-1</sup> at the current density of 1 A g<sup>-1</sup>, and 182 F g<sup>-1</sup> even at the current density of 10 A g<sup>-1</sup>. After 10 000 full cycles, the capacitance retention is 97%. The hybrid is of great promise for practical application. ©The Royal Society of Chemistry 2014.
语种：
英文
展开
Multifractal detrended moving average analysis for texture representation
WOS被引频次：10
SCI-E
作者：
Wang, Fang* ;Wang, Lin;Zou, Rui-Biao
期刊：
Chaos (Woodbury, N.Y.) ,2014年24(3):033127 ISSN：1054-1500
通讯作者：
Wang, Fang
作者机构：
[Zou, Rui-Biao; Wang, Fang] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Wang, Lin] Univ New Brunswick, Dept Math & Stat, Fredericton, NB E3B 5A3, Canada.
通讯机构：
[Wang, Fang] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
摘要：
Multifractal detrended moving average analysis (MF-DMA) is recently employed to detect long-range correlation and multifractal nature in stationary and non-stationary time series. In this paper, we propose a method to calculate the generalized Hurst exponent for each pixel of a surface based on MF-DMA, which we call the MF-DMA-based local generalized Hurst exponent. These exponents form a matrix, which we denote by LHq. These exponents are similar to the multifractal detrended fluctuation analysis (MF-DFA)-based local generalized Hurst exponent. The performance of the calculated LHq is tested for two synthetic multifractal surfaces and ten randomly chosen natural textures with analytical solutions under three cases, namely, backward (θ = 0), centered (θ = 0.5), and forward (θ = 1) with different q values and different sub-image sizes. Two sets of comparison segmentation experiments between the three cases of the MF-DMA-based LHq and the MF-DFA-based LHq show that the MF-DMA-based LHq is superior to the MF-DFA-based LHq. In addition, the backward MF-DMA algorithm is more efficient than the centered and forward algorithms. An interest finding is that the LHq with q < 0 outperforms the LHq with q > 0 in characterizing the image features of natural textures for both the MF-DMA and MF-DFA algorithms. © 2014 AIP Publishing LLC.
语种：
英文
展开
Aniline ortho C−H Sulfuration/Cyclization with Elemental Sulfur for Efficient Synthesis of 2‐Substituted Benzothiazoles under Metal‐Free Conditions
WOS被引频次：10
SCI-E
作者：
Jiang, Jingjing;Li, Guozheng;Zhang, Feng* ;Xie, Hao;Deng, Guo-Jun*
期刊：
Advanced Synthesis and Catalysis ,2018年360(8):1622-1627 ISSN：1615-4150
通讯作者：
Zhang, Feng;Deng, Guo-Jun
作者机构：
[Zhang, Feng; Deng, GJ; Xie, Hao; Li, Guozheng; Jiang, Jingjing; Deng, Guo-Jun] Xiangtan Univ, Key Lab Green Organ Synth & Applicat Hunan Prov, Key Lab Environm Friendly Chem & Applicat, Minist Educ,Coll Chem, Xiangtan 411105, Peoples R China.;[Zhang, Feng] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Zhang, F; Deng, GJ] Xiangtan Univ, Key Lab Green Organ Synth & Applicat Hunan Prov, Key Lab Environm Friendly Chem & Applicat, Minist Educ,Coll Chem, Xiangtan 411105, Peoples R China.;[Zhang, Feng] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
关键词：
2-substituted benzothiazoles;aromatic amines;elemental sulfur;metal-free
摘要：
A three-component synthesis of 2-substituted benzothiazoles from aryl amines, elemental sulfur and styrenes or aryl acetylenes in 1-methylpyrrolidin-2-one (NMP) is described. Two C−S and one C−N bonds were selectively formed in one-pot under metal-free conditions. (Figure presented.). © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
语种：
英文
展开
TBAI-catalyzed selective synthesis of sulfonamides and β-aryl sulfonyl enamines: coupling of arenesulfonyl chlorides and sodium sulfinates with tert-amines
WOS被引频次：10
ESI高被引 SCI-E
作者：
Jiang, Hongmei;Tang, Xiaoyue;Xu, Zhihui;Wang, Huixian;Han, Kang;Yang, Xiaolan;Zhou, Yuanyuan;Feng, Yong-Lai;Yu, Xian-Yong;Gui, Qingwen*
期刊：
Organic and Biomolecular Chemistry ,2019年17(10):2715-2720 ISSN：1477-0520
通讯作者：
Gui, Qingwen
作者机构：
[Zhou, Yuanyuan; Han, Kang; Tang, Xiaoyue; Yang, Xiaolan; Gui, Qingwen; Wang, Huixian; Feng, Yong-Lai; Jiang, Hongmei] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Gui, Qingwen; Xu, Zhihui; Jiang, Hongmei] Hunan Univ, Coll Chem & Chem Engn, State Key Lab Chemo Biosensing & Chemometr, Changsha 410082, Hunan, Peoples R China.;[Yu, Xian-Yong] Hunan Univ Sci & Technol, Minist Educ, Key Lab Theoret Organ Chem & Funct Mol, Taoyuan Rd 9, Xiangtan 411201, Peoples R China.
通讯机构：
[Gui, Qingwen] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Gui, Qingwen] Hunan Univ, Coll Chem & Chem Engn, State Key Lab Chemo Biosensing & Chemometr, Changsha 410082, Hunan, Peoples R China.
摘要：
A simple, practical and metal-free method has been developed for the synthesis of sulfonamides and β-arylsulfonyl enamines via the selective cleavage of C-N and C-H bonds through the iodine-catalyzed oxidation of arenesulfonyl chlorides and sodium sulfinates with tert-amines. The method uses commercially available inexpensive catalysts and oxidants, and has a wide substrate scope and operational simplicity. © The Royal Society of Chemistry.
语种：
英文
展开
Rhodium-catalyzed oxidative decarbonylative Heck-type coupling of aromatic aldehydes with terminal alkenes
WOS被引频次：10
SCI-E EI
作者：
Kang, Lei;Zhang, Feng;Ding, Lin-Ting;Yang, Luo*
期刊：
RSC Advances ,2015年5(122):100452-100456 ISSN：2046-2069
通讯作者：
Yang, Luo
作者机构：
[Ding, Lin-Ting; Kang, Lei; Yang, Luo] Xiangtan Univ, Coll Chem, Minist Educ, Key Lab Environm Friendly Chem & Applicat, Xiangtan 411105, Hunan, Peoples R China.;[Zhang, Feng] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Yang, Luo] Xiangtan Univ, Coll Chem, Minist Educ, Key Lab Environm Friendly Chem & Applicat, Xiangtan 411105, Hunan, Peoples R China.
摘要：
A rhodium-catalyzed oxidative decarbonylative Heck-type coupling of aromatic aldehydes with terminal alkenes to afford 1,2-disubstituted alkenes with good regio- and E-selectivity is developed. This reaction employs readily available aromatic aldehydes as the aryl electrophile counterpart and relies on selected acyl chloride as the crucial additive to activate the rhodium catalyst precursor. ©The Royal Society of Chemistry 2015.
语种：
英文
展开
Simultaneous melting of shell and core atoms, a molecular dynamics study of lithium–copper nanoalloys
WOS被引频次：10
SCI-E EI
作者：
Tang, Jianfeng;Yang, Jianyu*
期刊：
Journal of Nanoparticle Research ,2015年17(7):299- ISSN：1388-0764
通讯作者：
Yang, Jianyu
作者机构：
[Tang, Jianfeng] Hunan Agr Univ, Dept Appl Phys, Changsha 410128, Hunan, Peoples R China.;[Yang, Jianyu] Hunan Inst Engn, Xiangtan 411104, Peoples R China.
通讯机构：
[Yang, Jianyu] Hunan Inst Engn, Xiangtan 411104, Peoples R China.
关键词：
Energy storage;Melting;Modeling and simulation;Molecular dynamics;Nanoalloy;Solid–liquid interface
摘要：
Melting of nanoalloys originates from the alloy surface and gradually propagates into the interior region. The thermal stability of Li cores and Cu shells nanoalloy with size of 3.5 nm is studied through molecular dynamics and embedded atom method with the use of potential energy, Lindemann index, and radial distribution function. Results show that the shell and core Li atoms are melted in two steps: first, some Li atoms in the core migrate to the nanoalloy surface and maintain a typical solid state despite that the system temperature is higher than the bulk melting point of Li because of Li solidification in the solid–liquid interface; second, the shell and core Li atoms are simultaneously melted at high temperatures. A comparative study of [email protected] nanoalloys with different Li atomic numbers shows that thermal stability is enhanced with the decreasing number of Li atoms within the nanoalloys because of weak binding for Cu thin shells. © 2015, Springer Science+Business Media Dordrecht.
语种：
英文
展开
High-performance LiTi2 (PO4 )3 @carbon anode using double carbon sources for aqueous lithium ion battery
WOS被引频次：10
SCI-E EI
作者：
Zhou, Nan;Huang, Shengxiong;Hong, Tao;Luo, Wei;Tian, Yun;Lu, Xiangyang;Zhou, Zhi*
期刊：
Ceramics International ,2017年43(12):9327-9333 ISSN：0272-8842
通讯作者：
Zhou, Zhi
作者机构：
[Hong, Tao; Huang, Shengxiong; Luo, Wei; Zhou, Nan; Zhou, Zhi] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Tian, Yun; Lu, Xiangyang; Zhou, Nan; Zhou, Zhi] Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.;[Tian, Yun; Lu, Xiangyang; Zhou, Nan; Zhou, Zhi] Hunan Agr Univ, Hunan Prov Univ Key Lab Agr Biochem & Biotransfor, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Zhou, Zhi] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
关键词：
Anode;Aqueous lithium ion battery;Composite;Double carbon sources;LiTi 2 (PO 4 ) 3
摘要：
In this paper, LiTi<inf>2</inf>(PO<inf>4</inf>)<inf>3</inf>@carbon composite as anode for aqueous lithium ion battery has been successfully synthesized by in-situ carbon coating method using oxalic acid and glucose as double carbon sources. XRD results confirm the rhombohedral NASICON-type LiTi<inf>2</inf>(PO<inf>4</inf>)<inf>3</inf>structure of the as-prepared composite. The LiTi<inf>2</inf>(PO<inf>4</inf>)<inf>3</inf>@carbon composite using double carbon sources (LTP-OG-10) disperses well, and the coated carbon layer has the appropriate thickness of 3–7 nm, which result in proper balance of the good electrical conductivity and the fast kinetics of diffusion of lithium ions. LTP-OG-10 exhibits better electrochemical performance compared with those using oxalic acid (LTP-O) or glucose (LTP-G) single carbon source. LTP-OG-10 anode delivers the discharge capacity of 112.5 mA h g<sup>−1</sup>, 96.8 mA h g<sup>−1</sup>, and 54.2 mA h g<sup>−1</sup>at 0.2 C, 5 C and 20 C, respectively, much larger than that of LTP-O and LTP-G. Moreover, LTP-OG-10 demonstrated excellent cycling performance, with the capacity retention of 71.1% after 400 cycles at 0.2 C, 22.9% higher than that of LTP-G. The good electrochemical properties of LTP-OG-10 is mainly ascribed to the increase of defects, high-quality and appropriate thickness of carbon layer. Our study reveals that preparing LiTi<inf>2</inf>(PO<inf>4</inf>)<inf>3</inf>@carbon composite using double carbon sources is an efficient approach to enhance its electrochemical properties. ©2017 Elsevier Ltd and Techna Group S.r.l.
语种：
英文
展开
Effects of solute size on solid-solution hardening in vanadium alloys: A first-principles calculation
WOS被引频次：9
SCI-E EI
作者：
Zhang, Xingming;Tang, Jianfeng;Deng, Lei;Deng, Huiqiu* ;Xiao, Shifang;Hu, Wangyu
期刊：
Scripta Materialia ,2015年100:106-109 ISSN：1359-6462
通讯作者：
Deng, Huiqiu
作者机构：
[Xiao, Shifang; Deng, Huiqiu; Hu, Wangyu; Zhang, Xingming] Hunan Univ, Sch Phys & Elect, Dept Appl Phys, Changsha 410082, Hunan, Peoples R China.;[Deng, Lei; Tang, Jianfeng; Zhang, Xingming] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Deng, Huiqiu] Hunan Univ, Sch Phys & Elect, Dept Appl Phys, Changsha 410082, Hunan, Peoples R China.
关键词：
Vanadium alloys;Solute size;Solubility;Stacking fault energy;First-principles calculation
摘要：
We performed first-principles calculations to quantify the effect of 26 transition metals on the mechanical properties of vanadium (V) alloys. The generalized stacking-fault (GSF) energies of the solutes were evaluated in three slip systems. Solutes with similar atomic radii to that of V present high GSF energies, which increase the energy barrier for double-kink nucleation and result in excellent strengthening effect. This size effect indicates that noble metals can significantly improve the mechanical strength of V alloys.
语种：
英文
展开
Photoluminescence properties and energy transfer in a novel Sr8ZnY(PO4)(7):Tb3+,Eu3+ phosphor with high thermal stability and its great potential for application in warm white light emitting diodes
WOS被引频次：9
SCI-E
作者：
Xia, Mao;Wu, Xianbo;Zhong, Yuan;Hintzen, H. T. (Bert);Zhou, Zhi* ;Wang, Jing*
期刊：
Journal of Materials Chemistry C ,2019年7(10):2927-2935 ISSN：2050-7526
通讯作者：
Zhou, Zhi;Wang, Jing
作者机构：
[Xia, Mao; Zhong, Yuan; Wu, Xianbo; Zhou, Zhi] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Xia, Mao; Zhong, Yuan; Wu, Xianbo; Zhou, Zhi; Wang, Jing] Hunan Agr Univ, Hunan Opt Agr Engn Technol Res Ctr, Changsha, Hunan, Peoples R China.;[Xia, Mao] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.;[Hintzen, H. T. (Bert)] Delft Univ Technol, Fac Sci Appl, Sect Fundamental Aspects Mat & Energy, Grp Luminescent Mat, Delft, Netherlands.;[Wang, Jing] Sun Yat Sen Univ, Sch Chem, Sch Mat Sci & Engn, Guangzhou 510275, Guangdong, Peoples R China.
通讯机构：
[Zhou, Zhi] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Zhou, Z; Wang, J] Hunan Agr Univ, Hunan Opt Agr Engn Technol Res Ctr, Changsha, Hunan, Peoples R China.;[Wang, Jing] Sun Yat Sen Univ, Sch Chem, Sch Mat Sci & Engn, Guangzhou 510275, Guangdong, Peoples R China.
摘要：
Terbium and europium co-doped Sr8ZnY(PO4)7 phosphors are successfully prepared through a high temperature solid-state reaction (SSR). The crystal structure of the as-prepared samples was identified to be Sr8ZnY(PO4)7 (SZYP) pure phase by an X-ray powder diffraction technique. Under near-ultraviolet light excitation (378 nm), the SZYP:Tb3+ and SZYP:Eu3+ phosphors show green and red emission peaking at 545 and 618 nm, respectively. Moreover, an effective energy transfer process from Tb3+ to Eu3+ could be verified by the concentration dependence of emission intensity and lifetime. The energy transfer mechanism between Tb3+ and Eu3+ is determined to be governed by dipole-dipole interactions. The internal quantum efficiency (IQE) is evaluated to be as high as about 91%. The temperature-dependent spectra indicate that the SZYP:Tb3+,Eu3+ phosphor shows a high thermal stability. Furthermore, the as-fabricated white LED devices exhibit an excellent correlated color temperature (CCT) of 3223 K, a color rendering index (Ra) of 85.8 and a luminance efficiency of 37.4 lm W-1. All results imply that the SZYP:Tb3+,Eu3+ phosphors have a great potential for application in white LEDs. © 2019 The Royal Society of Chemistry.
语种：
英文
展开
First-principles study of the binding preferences and diffusion behaviors of solutes in vanadium alloys
WOS被引频次：9
SCI-E EI
作者：
Deng, Lei;Zhang, Xingming;Tang, Jianfeng;Deng, Huiqiu;Xiao, Shifang;Hu, Wangyu*
期刊：
Journal of Alloys and Compounds ,2016年660:55-61 ISSN：0925-8388
通讯作者：
Hu, Wangyu
作者机构：
[Deng, Lei; Tang, Jianfeng; Zhang, Xingming] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Tang, Jianfeng; Hu, Wangyu] Hunan Univ, Coll Mat Sci & Engn, Changsha 410082, Hunan, Peoples R China.;[Xiao, Shifang; Deng, Huiqiu; Hu, Wangyu] Hunan Univ, Sch Phys & Elect, Dept Appl Phys, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Hu, Wangyu] Hunan Univ, Sch Phys & Elect, Dept Appl Phys, Changsha 410082, Hunan, Peoples R China.
关键词：
First-principles calculations;Solute diffusion;Solute-solute binding;Solute-vacancy binding;V alloys
摘要：
In order to elucidate the role of solutes in vanadium alloys, the solute diffusions and the interactions of solute-solute and solute-vacancy have been investigated by means of the first-principles calculations. It is shown that large solutes are energetically favorable to combine with adjacent solute and to form the solute-solute nearest-neighbor pairs. In order to obtain qualitative understanding, the charge density differences for some special solute-solute binding are plotted to analyze the bonding interaction between solute atom and their nearest-neighbor host atoms. The solute-solute binding energies indicated that apart from the 3d transition metals, there is a clear trend of increasing binding energy with increasing solute volume. In particular, large solutes have larger binding energies for bonding with vacancies and can be considered as vacancy trappers in the crystal. As a comparison with solute diffusions, the self-diffusion coefficients of vanadium are determined. Activation energies for vacancy-mediated solute diffusion in vanadium are also determined. We conclude that the major contribution to the activation energy comes from the diffusion energy barrier, and both all follow the same trend. The noble metals have higher migration barriers than others, which means that these elements are inactive in the vanadium alloys. By contrast, the barriers for the large solutes almost cease to exist due to the formation of stable solute-centered divacancy. ©2015 Published by Elsevier B.V.
语种：
英文
展开
Variational methods to the second-order impulsive differential equation with Dirichlet boundary value problem
WOS被引频次：9
SCI-E EI
作者：
Liu, Zhisu;Chen, Haibo* ;Zhou, Tiejun
期刊：
Computers & Mathematics with Applications ,2011年61(6):1687-1699 ISSN：0898-1221
通讯作者：
Chen, Haibo
作者机构：
[Chen, Haibo; Liu, Zhisu] Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.;[Zhou, Tiejun] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Chen, Haibo] Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.
关键词：
Dirichlet boundary value problem;Impulsive effects;Variational methods;Critical points
摘要：
In this paper, we study the existence of solutions for a class of second-order impulsive differential equation. By using the critical point theorem of Y. Jabri and an even functional theorem, we give some new criteria to guarantee that the impulsive differential equation has at least one solution, infinitely many solutions under the assumption that a nonlinear term satisfies sublinear, superlinear, asymptotically linear, respectively. Some recent results are extended and conditions of assumptions are simplified. Finally, some examples are presented to illustrate our main results.
语种：
英文
展开
Influence of Encapsulated Water on Luminescence Energy, Line Width, and Lifetime of Carbon Nanotubes: Time Domain Ab Initio Analysis
WOS被引频次：9
SCI-E EI
作者：
Li, Wei* ;Long, Run;Hou, Zhufeng;Tang, Jianfeng;Prezhdo, Oleg V.*
期刊：
Journal of Physical Chemistry Letters ,2018年9(14):4006-4013 ISSN：1948-7185
通讯作者：
Li, Wei;Prezhdo, Oleg V.
作者机构：
[Tang, Jianfeng; Li, Wei] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Li, Wei] Jilin Univ, Inst Theoret Chem, Lab Theoret & Computat Chem, Changchun 130023, Jilin, Peoples R China.;[Long, Run] Beijing Normal Univ, Minist Educ, Coll Chem, Key Lab Theoret & Computat Photochem, Beijing 100875, Peoples R China.;[Hou, Zhufeng] NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 3050047, Japan.;[Prezhdo, Oleg V.] Univ Southern Calif, Dept Chem, Los Angeles, CA 90089 USA.
通讯机构：
[Li, Wei] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Li, Wei] Jilin Univ, Inst Theoret Chem, Lab Theoret & Computat Chem, Changchun 130023, Jilin, Peoples R China.;[Prezhdo, Oleg V.] Univ Southern Calif, Dept Chem, Los Angeles, CA 90089 USA.
摘要：
In a broad range of applications, carbon nanotubes (CNTs) are in direct contact with a condensed-phase environment that perturbs CNT properties. Experiments show that water molecules encapsulated inside of semiconducting CNTs reduce the electronic energy gap, enhance elastic and inelastic electron-phonon scattering, and shorten the excited-state lifetime. We rationalize the observed effects at the atomistic level using real-time time-dependent density functional theory combined with nonadiabatic molecular dynamics. Encapsulated water makes the nanotube more rigid, suppressing radial breathing modes while enhancing and slightly shifting the optical G-mode. Water screens Coulomb interactions and shifts charge carrier energies and wave functions. The screening, together with distortion of the CNT geometry and lifting of orbital degeneracy, produces a luminescence red shift. Enhanced elastic and inelastic electron-phonon scattering explains line width broadening and shortening of the excited-state lifetime. The influence of water on the CNT properties is similar to that of defects;however, in contrast to defects, water creates no new phonon modes or electronic states in the CNTs. The atomistic understanding of the influence of the condensed-phase environment on CNT optical, electronic, and vibrational properties, and electron-vibrational dynamics guides design of novel CNT-based materials.<br/> Copyright ©2018 American Chemical Society.
语种：
英文
展开
Stage extraction of capsaicinoids and red pigments from fresh red pepper (Capsicum) fruits with ethanol as solvent
WOS被引频次：8
SCI-E EI
作者：
Dong, Xinrong* ;Li, Xia;Ding, Lei;Cui, Fuzhi;Tang, Zuojiao;Liu, Zhonghua
期刊：
LWT - Food Science and Technology ,2014年59(1):396-402 ISSN：0023-6438
通讯作者：
Dong, Xinrong
作者机构：
[Dong, Xinrong; Cui, Fuzhi; Tang, Zuojiao; Ding, Lei; Li, Xia] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Liu, Zhonghua; Dong, Xinrong] Hunan Agr Univ, Natl Res Ctr, Engn Technol Funct Ingredients Bot, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Dong, Xinrong] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
关键词：
Stage extraction;Capsaicinoids;Red pigments;Carotenoids;Fresh red pepper (Capsicum)
摘要：
A method for stage extraction of capsaicinoids and red pigments from fresh red peppers (FRPs) was developed in this work. Firstly, capsaicinoids were extracted from FRPs without any drying process by 40%-50% ethanol. Then red colorants without piquancy were extracted from the residues after removal of capsaicinoids using 95% ethanol as solvent with the conditions of 90 degrees C of temperature of water bath, 4 mL/g of ratio of solvent to material and 120 min of extraction time. The yield of red pigments were 89.8% of total content of red colorants in FRPs, which is about 2.2 times that of dry red peppers (DRPs) dried from equivalent FRPs. Compared with conventional methods, the new processes were simple, but gave a high yield of red pigments without remain of toxic solvent. (C) 2014 Elsevier Ltd. All rights reserved.
语种：
英文
展开
Folate-conjugated Fe3O4 nanoparticles for in vivo tumor labeling
WOS被引频次：8
SCI-E EI CSCD
作者：
Zhou, Chun-jiao;Wang, Shao-hua;Zhou, Yu;Rong, Peng-fei;Chen, Zi-zi;Liu, Jin-yan;Zhou, Jian-da*
期刊：
Transactions of Nonferrous Metals Society of China ,2013年23(7):2079-2084 ISSN：1003-6326
通讯作者：
Zhou, Jian-da
作者机构：
[Zhou, Chun-jiao; Zhou, Yu] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Zhou, Jian-da; Chen, Zi-zi; Wang, Shao-hua; Liu, Jin-yan; Rong, Peng-fei] Cent S Univ, Xiangya Hosp 3, Changsha 410013, Hunan, Peoples R China.
通讯机构：
[Zhou, Jian-da] Cent S Univ, Xiangya Hosp 3, Changsha 410013, Hunan, Peoples R China.
关键词：
Fe3O4 nanoparticles;superparamagnetic property;folic acid;tumor;conjugation;magnetic resonance imaging (MRI);cell labeling
摘要：
Highly biocompatible superparamagnetic Fe<inf>3</inf>O<inf>4</inf> nanoparticles were synthesized by amide of folic acid (FA) ligands and the NH<inf>2</inf>-group onto the surface of Fe<inf>3</inf>O<inf>4</inf> nanoparticles. The as-synthesized folate-conjugated Fe<inf>3</inf>O<inf>4</inf> nanoparticles were characterized by X-ray diffraction diffractometer, transmission electron microscope, FT-IR spectrometer, vibrating sample magnetometer, and dynamic light scattering instrument. The in vivo labeling effect of folate-conjugated Fe<inf>3</inf>O<inf>4</inf> nanoparticles on the hepatoma cells was investigated in tumor-bearing rat. The results demonstrate that the as-prepared nanoparticles have cubic structure of Fe<inf>3</inf>O <inf>4</inf> with a particle size of about 8 nm and hydrated diameter of 25.7 nm at a saturation magnetization of 51 A·m<sup>2</sup>/kg. These nanoparticles possess good physiological stability, low cytotoxicity on human skin fibroblasts and negligible effect on Wistar rats at the concentration as high as 3 mg/kg body mass. The folate-conjugated Fe<inf>3</inf>O<inf>4</inf> nanoparticles could be effectively mediated into the human hepatoma Bel 7402 cells through the binding of folate and folic acid receptor, enhancing the signal contrast of tumor tissue and surrounding normal tissue in MRI imaging. It is in favor of the tumor cells labeling, tracing, magnetic resonance imaging (MRI) target detection and magnetic hyperthermia. ©2013 The Nonferrous Metals Society of China.
语种：
英文
展开
Rapid green synthesis of gold nanocatalyst for high-efficiency degradation of quinclorac
WOS被引频次：8
SCI-E EI Medline
作者：
Shi, Guorong* ;Li, Yulu;Xi, Gaihong;Xu, Qinqin;He, Zijun;Liu, Yating;Zhang, Jianhui;Cai, Jun
期刊：
Journal of Hazardous Materials ,2017年335(Volume 335):170-177 ISSN：0304-3894
通讯作者：
Shi, Guorong
作者机构：
[Shi, Guorong; Xu, Qinqin; Cai, Jun; He, Zijun; Li, Yulu] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Liu, Yating; Shi, Guorong; Xi, Gaihong] Hunan Agr Univ, Tobacco Res Inst, Changsha 410128, Hunan, Peoples R China.;[Zhang, Jianhui] Hunan Inst Food Qual Supervis Inspect & Res, Changsha 410111, Hunan, Peoples R China.
通讯机构：
[Shi, Guorong] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
关键词：
Au NPs;gold nanoparticles;Au/SCM;gold nanoparticles immobilized on NaOH-pretreated yeast;SPR;surface plasmon resonance;kobs;rate constant;Quinclorac;Saccharomyces cerevisiae;Nanoparticle;Catalyst;Reductive dechlorination
摘要：
Porous chemical pretreated Saccharomyces cerevisiae was used as support, stabilizer, and reducing agent for the rapid green synthesis of gold nanocatalyst. Au nanoparticles (Au NPs) were generated through in-situ reduction of the absorbed Au(III) by the reductive functional groups of mannoproteins in yeast cell wall. The obtained spherical mono-dispersed Au NPs have an average particle diameter of 9.99 ± 1.63 nm as evidenced by TEM image, and exhibits excellent catalytic activity for the dechlorination of quinclorac to 8-quinoline-carboxylic acid by sodium borohydride. The reductive dechlorination of quinclorac is chemical reaction controlled and follows pseudo-first-order kinetic model. The rate constant increases with the increase of the temperature and decrease of the initial quinclorac concentration. The present synthesis protocol of Au nanocatalyst has the advantages of rapid, convenient and mild operation, high catalytic dechlorination efficiency and organic solvent-free nature. ©2017 Elsevier B.V.
语种：
英文
展开
LSQR iterative common symmetric solutions to matrix equations AXB = e and CXD = F
WOS被引频次：8
SCI-E EI
作者：
Chen, Yabo;Peng, Zhenyun;Zhou, Tiejun*
期刊：
Applied Mathematics and Computation ,2010年217(1):230-236 ISSN：0096-3003
通讯作者：
Zhou, Tiejun
作者机构：
[Chen, Yabo; Zhou, Tiejun] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Peng, Zhenyun] Guilin Univ Elect Technol, Guilin 541004, Peoples R China.
通讯机构：
[Zhou, Tiejun] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
关键词：
Iterative method;Matrix equation;Least-squares problem;Matrix nearness problem
摘要：
A new matrix based iterative method is presented to compute common symmetric solution or common symmetric least-squares solution of the pair of matrix equations AXB = E and CXD = F. By this iterative method, for any initial matrix X<inf>0</inf>, a solution X<sup>*</sup> can be obtained within finite iteration steps if exact arithmetic was used, and the solution X <sup>*</sup> with the minimum Frobenius norm can be obtained by choosing a special kind of initial matrix. In addition, the unique nearest common symmetric solution or common symmetric least-squares solution X to given matrix X in Frobenius norm can be obtained by first finding the minimum Frobenius norm common symmetric solution or common symmetric least-squares solution of the new pair of matrix equations. The given numerical examples show that the matrix based iterative method proposed in this paper has faster convergence than the iterative methods proposed in [1,2] to solve the same problems. ©2010 Elsevier Inc. All rights reserved.
语种：
英文
展开
Efficient synthesis of 1,2-benzisothiazoles from: O -haloarylamidines and elemental sulfur via N-S/C-S bond formation under transition-metal-free conditions
WOS被引频次：8
SCI-E
作者：
Xie, Hao;Li, Guozheng;Zhang, Feng* ;Xiao, Fuhong;Deng, Guo-Jun*
期刊：
Green Chemistry ,2018年20(4):827-831 ISSN：1463-9262
通讯作者：
Deng, Guo-Jun;Zhang, Feng
作者机构：
[Xie, Hao; Li, Guozheng; Deng, Guo-Jun; Xiao, Fuhong] Xiangtan Univ, Coll Chem, Key Lab Green Organ Synth & Applicat Hunan Prov, Key Lab Environm Friendly Chem & Applicat,Minist, Xiangtan 411105, Peoples R China.;[Zhang, Feng] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Deng, Guo-Jun] Xiangtan Univ, Coll Chem, Key Lab Green Organ Synth & Applicat Hunan Prov, Key Lab Environm Friendly Chem & Applicat,Minist, Xiangtan 411105, Peoples R China.;[Zhang, Feng] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
摘要：
An efficient method for the synthesis of 1,2-benzisothiazoles from amidines and elemental sulfur via N-S/C-S bond formation under transition-metal-free conditions is described. This reaction is performed smoothly under simple conditions to give the corresponding products in good to high yields with good functional group tolerance. © The Royal Society of Chemistry.
语种：
英文
展开
