Research on Zr50 Al15 Ni10 Cu25 bulk amorphous alloys prepared by mechanical alloying and low pressure sintering
作者：
Long, W. Y.* ;Ouyang, X. Q.;Zuo, C. G.;Zhu, L. G.;Gao, C.;...
期刊：
Powder Metallurgy ,2011年54(3):257-261 ISSN：0032-5899
通讯作者：
Long, W. Y.
作者机构：
[Zhu, L. G.; Long, W. Y.; Gao, C.; Zuo, C. G.; Ouyang, X. Q.; Lu, A. X.] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.;[Long, W. Y.] Hunan Agr Univ, Dept Appl Phys, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Long, W. Y.] C;Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.
关键词：
Mechanical alloying;Amorphous alloys;Activation energy;Low pressure sintering
摘要：
Amorphous Zr<inf>50</inf>Al<inf>15</inf>Ni<inf>10</inf>Cu<inf>25</inf> alloy powders were fabricated by mechanical alloying technique with commercially pure element powders. The effects of small amount of C, Si<inf>3</inf>N <inf>4</inf> and SiC powders addition on the thermal stability and crystallisation behaviour of the Zr<inf>50</inf>Al<inf>15</inf>Ni <inf>10</inf>Cu<inf>25</inf> amorphous alloy were investigated. The blended powders were compacted into bars by oil hydraulic press, and were sintered in argon atmosphere at different temperatures and pressures. The samples before and after sintering were characterised by X-ray diffraction, scanning electron microscopy, differential scanning calorimetry and electron tensile testing machine. The results demonstrated that a proper addition of Si<inf>3</inf>N <inf>4</inf> powders to the amorphous matrix can improve the thermal stability of the matrix. Suitable additives can help to improve the density and mechanical properties of the matrix in sintering process. ©2011 Institute of Materials, Minerals and Mining.
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Strong stability of the mono-tubular heat exchanger equation with output feedback
作者：
Chen, Jian-Hua* ;Lu, Wen-Ying;Peng, Dao-Lin
期刊：
Systems & Control Letters ,2011年60(1):15-18 ISSN：0167-6911
通讯作者：
Chen, Jian-Hua
作者机构：
[Lu, Wen-Ying; Chen, Jian-Hua] Hunan Univ Sci & Technol, Sch Math & Computat Sci, Xiangtan 411201, Hunan, Peoples R China.;[Peng, Dao-Lin] Hunan Agr Univ, Sch Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Chen, Jian-Hua] H;Hunan Univ Sci & Technol, Sch Math & Computat Sci, Xiangtan 411201, Hunan, Peoples R China.
关键词：
Mono-tubular heat exchanger equation;C(0)-semigroup;Strong stability;Miyadera-Voigt perturbation
摘要：
We investigate asymptotic behavior of the C0-semigroup T(t) associated with the mono-tubular heat exchanger equation with output feedback by a perturbation method. It is shown that T(t) is bounded if a constraint is satisfied by the parameters and the spatial distribution function. Further, applying the Arendt–Batty–Lyubich–Vu theorem, a criterion is established to judge strong stability of T(t).
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英文
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Correction to the Dirac field entropy of a Schwarzschild black hole by a modified dispersion relation
作者：
Zhao, Fan* ;He, Feng;Tang, JianFeng
期刊：
PHYSICAL REVIEW D ,2011年84(10):104007 ISSN：2470-0010
通讯作者：
Zhao, Fan
作者机构：
[Zhao, Fan] Hunan Agr Univ, Orient Sci & Technol Coll, Changsha 410128, Hunan, Peoples R China.;[Tang, JianFeng; Zhao, Fan] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[He, Feng] Hunan Univ Sci & Technol, Coll Phys & Elect Sci, Xiangtan 411201, Peoples R China.
通讯机构：
[Zhao, Fan] H;Hunan Agr Univ, Orient Sci & Technol Coll, Changsha 410128, Hunan, Peoples R China.
摘要：
Taking the WKB approximation to solve the Dirac field equation in a Schwarzschild black hole spacetime, we can get the classical momenta. Employing the classical momenta and state density equation corrected by a modified dispersion relation, we will obtain the number of quantum states with energy less than ω. Then, it is used to calculate the statistical-mechanical entropy of the Dirac field. Solving the integral for r exactly, we obtain the leading term of entropy that is proportional to the event horizon area, and correction terms take the form of A−1, but the logarithmic correction term by this approach is not given.
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Low temperature synthesis of high quality carbon nanospheres through the chemical reactions between calcium carbide and oxalic acid
作者：
Xie, Yonggui* ;Huang, Qizhong;Huang, Baiyun;Xie, Xiangmin
期刊：
Materials Chemistry and Physics ,2010年124(1):482-487 ISSN：0254-0584
通讯作者：
Xie, Yonggui
作者机构：
[Huang, Baiyun; Xie, Yonggui; Huang, Qizhong] Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.;[Xie, Xiangmin] Hunan Agr Univ, Dept Appl Chem, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Xie, Yonggui] C;Cent S Univ, State Key Lab Powder Met, Changsha 410083, Hunan, Peoples R China.
关键词：
Chemical synthesis;Electron microscopy;Nanostructures;Raman spectroscopy
摘要：
Carbon nanospheres (CNSs) were synthesized through the chemical reactions of calcium carbide and oxalic acid without using catalysts. The chemical reactions were carried out in a sealed stainless steel pressure vessel with various molar ratios at temperatures of 65–250 °C. The synthesized CNSs have been characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) attached to the SEM, transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectroscopy. The total yield of carbonaceous materials relative to the starting material is about 4% (w/w). SEM and TEM results reveal that the percentage of CNSs is high (>95%). The CNSs that have been synthesized are roe-like spheres of relatively uniform size with diameters of 60–120 nm. The attached EDS result shows that the carbon content of CNSs reaches up to 98%.
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Preparation of Biodiesel by Transesterification of Rapeseed Oil with Methanol Using Solid Base Catalyst Calcined K2CO3/gamma-Al2O3
作者：
Liu, Xianghua;Xiong, Xingyao;Liu, Canming* ;Liu, Dengyou;Wu, Anjun;...
期刊：
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY ,2010年87(7):817-823 ISSN：0003-021X
通讯作者：
Liu, Canming
作者机构：
[Wu, Anjun; Liu, Canming; Liu, Xianghua; Liu, Dengyou] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Liu, Chunlin; Liu, Xianghua; Xiong, Xingyao] Key Lab Plant Resource Utilizat Hunan Prov, Changsha 410128, Hunan, Peoples R China.;[Hu, Qiulong] Hunan Agr Univ, Coll Hort & Gardening, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Liu, Canming] H;Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
关键词：
Biodiesel;Methanol;Rapeseed oil;Solid base catalyst;Transesterification
摘要：
We report here the preparation of biodiesel by transesterification of rapeseed oil with methanol using calcined K2CO3/gamma-Al2O3 as a solid base catalyst. The prepared catalysts were characterized using SEM, IR and BET, and their catalytic activities were evaluated. The reaction conditions were optimized, and in particular, the conversion can be as high as 98.62% under the optimal reaction conditions. In addition, the effect of the presence of water in the reaction system on the catalytic activity was also studied.
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英文
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Simultaneous separation of four flavonoids and two astragalosides from radix astragali by semi-preparative LC
作者：
Dong, Xinrong;Liang, Yizeng* ;Wang, Bing;Long, Xiaohong
期刊：
Chromatographia ,2010年71(3-4):225-231 ISSN：0009-5893
通讯作者：
Liang, Yizeng
作者机构：
[Dong, Xinrong; Liang, Yizeng; Wang, Bing] Cent S Univ, Coll Chem & Chem Engn, Res Ctr Modernizat Chinese Med, Changsha 410083, Peoples R China.;[Dong, Xinrong; Long, Xiaohong] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Liang, Yizeng] C;Cent S Univ, Coll Chem & Chem Engn, Res Ctr Modernizat Chinese Med, Changsha 410083, Peoples R China.
关键词：
Column liquid chromatography;Preparative LC;Macroporous resin;Isoflavonoids;Astragaloside;Radix Astragali
摘要：
An effective method for simultaneous separation of four flavonoids and two astragalosides was developed by semi-preparative high-performance liquid chromatography in this work. A crude sample was firstly cleaned-up from ethanol aqueous extract of Radix Astragali by LS-300B resin-based column chromatography and was further isolated by semi-preparative LC with a gradient elution of water-methanol. Six compounds including calycosin (3.5 mg), formononetin (2.6 mg), (6aR,11aR)-10-hydroxy-3,9-dimethoxypterocarpan (2.6 mg), (3R)-7,2′-dihydroxy-3′,4′-dimethoxyisoflavan) (2.0 mg), astragaloside I (5.4 mg) and astragaloside II (9.8 mg) were obtained with a recovery of 67.8, 77.2, 88.4, 85.3, 62.1 and 57.9%, respectively. Their chemical structures were confirmed by MS and NMR analysis. This study developed an effective and rapid method for simultaneous separation of multiple components from Radix astragali. © 2010 Vieweg+Teubner | GWV Fachverlage GmbH.
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英文
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Entanglement dynamics of a double two-photon Jaynes-Cummings model with Kerr-like medium
作者：
Ouyang Xi-Cheng;Fang Mao-Fa* ;Kang Guo-Dong;Deng Xiao-Juan;Huang Li-Yuan
期刊：
中国物理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] H;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.
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Concentration of components in Danggui-Buxue Decoction by macroporous resin chromatography guided with LC
作者：
Dong, Xinrong;Liang, Yizeng* ;Wang, Bing
期刊：
Chromatographia ,2010年72(7-8):725-730 ISSN：0009-5893
通讯作者：
Liang, Yizeng
作者机构：
[Dong, Xinrong; Liang, Yizeng; Wang, Bing] Cent S Univ, Res Ctr Modernizat Chinese Med, Coll Chem & Chem Engn, Changsha 410083, Peoples R China.;[Dong, Xinrong] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Liang, Yizeng] C;Cent S Univ, Res Ctr Modernizat Chinese Med, Coll Chem & Chem Engn, Changsha 410083, Peoples R China.
关键词：
Column liquid chromatography;Concentration of bioactive components;Astragalus membranaceus;Angelicae sinensis
摘要：
A method for simultaneous concentration of multiple bioactive components (MBCs) in Danggui-Buxue Decoction (DBD) was comprehensively investigated in this work. The column chromatography with macroporous resin ADS-7 as an absorbent was used for concentration of the MBCs in DBD under the guidance of liquid chromatography (LC). After one-run treatment with the resin, the contents of major flavonoids reached 18.3 and 13.9% in the eluting fraction of 50 and 70% ethanol, which were 177.2 and 134.6 times higher than those in DBD crude extract. The contents of main saponins reached 8.7 and 9.9% in the eluting fractions of 10 and 30% ethanol, which were 32.8 and 37.3 times higher than those in DBD crude extract; and ferulic acid and ligustilide were also enriched in the eluting fractions of 10 and 70% ethanol. © 2010 Vieweg+Teubner Verlag | Springer Fachmedien Wiesbaden GmbH.
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英文
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Surface self-diffusion of a Pt adatom on cuboctahedral and truncated decahedral clusters, size dependence
作者：
Yang, J. Y.* ;Hu, W. Y.;Tang, J. F.
期刊：
EUROPEAN PHYSICAL JOURNAL B ,2010年78(3):315-321 ISSN：1434-6028
通讯作者：
Yang, J. Y.
作者机构：
[Yang, J. Y.] Hunan Inst Engn, Dept Math & Phys, Xiangtan 411104, Peoples R China.;[Hu, W. Y.] Hunan Univ, Dept Appl Phys, Changsha 410082, Hunan, Peoples R China.;[Tang, J. F.] Hunan Agr Univ, Dept Appl Phys, Changsha 410028, Hunan, Peoples R China.
通讯机构：
[Yang, J. Y.] H;Hunan Inst Engn, Dept Math & Phys, Xiangtan 411104, Peoples R China.
关键词：
The European Physical Journal B;Condensed Matter;Complex Systems;journal;EPJ
摘要：
The self-diffusion of single Pt adatom on the surface of cuboctahedral and truncated decahedral clusters with 561-10179 atoms are studied within the context of the many-body potentials obtained via the embedded atom method. The minimum energy diffusion path and the corresponding energy barrier for adatom diffusion on the cuboctahedral and truncated decahedral clusters surfaces are determined through a combination of the quenched molecular dynamics and the nudged elastic band method. The calculated energy barriers are consistent with the available experimental data. The dependence of energy barrier for adatom diffusion across the step edge on the cluster size is found. For the larger cuboctahedral and truncated decahedral clusters, the simulations show that the movement of the adatom is confined to a central region, and the adatom may escape from the center region only at elevated temperatures. In addition, we also find that the truncated decahedral structure is more favorable over the cuboctahedral structure for smaller clusters. The cluster growth experiments support our results. © 2010 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.
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英文
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Effect of reactant phase form on the properties of LiFePO4 synthesized by carbothermal reduction method
作者：
Zhong, Mei-e* ;Zhou, Zhentao
期刊：
Solid State Ionics ,2010年181(35-36):1607-1610 ISSN：0167-2738
通讯作者：
Zhong, Mei-e
作者机构：
[Zhong, Mei-e] Hunan Agr Univ, Coll Sci, Changsha 410128, Peoples R China.;[Zhou, Zhentao] S China Univ Technol, Coll Mat Sci & Engn, Guangzhou 510640, Guangdong, Peoples R China.
通讯机构：
[Zhong, Mei-e] H;Hunan Agr Univ, Coll Sci, Changsha 410128, Peoples R China.
关键词：
Carbothermal reduction method;Cathode;LiFePO4;Lithium ion batteries
摘要：
Pure olivine LiFePO<inf>4</inf>/C composite compounds are synthesized by carbothermal reduction (CTR) method using trigonal anhydrous FePO<inf>4</inf> raw material. The physical and electrochemical properties of the prepared samples are investigated in comparison with those of a sample obtained from incompletely crystallized hydrous FePO<inf>4</inf>•2H<inf>2</inf>O. The olivine LiFePO<inf>4</inf>/C prepared with trigonal anhydrous FePO<inf>4</inf> has a high discharge capacity of 142 mAh g<sup>- 1</sup> at 0.1 C. The composite also displays a better rate capability, a higher discharge capacity and a more stable cycle-life than that synthesized with incompletely crystallized hydrous FePO<inf>4</inf>•2H<inf>2</inf>O. The improved electrochemical performance of trigonal anhydrous FePO<inf>4</inf> synthesis samples originates mainly from the single-phase structure and small particle size. ©2010 Elsevier B.V. All rights reserved.
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英文
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LSQR iterative common symmetric solutions to matrix equations AXB = E and CXD = F
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] H;Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
关键词：
Iterative method;Least-squares problem;Matrix equation;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 X0, a solution X* can be obtained within finite iteration steps if exact arithmetic was used, and the solution X * 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.
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英文
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Si3N4-doped Zr50Al15Ni10Cu25 glassy alloy by mechanical alloying and sintering process
作者：
Ouyang Xue-qiong;Long Wo-yun;Bian Jian-ze;Gao Chao;Lu An-xian*
期刊：
中南大学学报(英文版) ,2010年17(6):1125-1128 ISSN：2095-2899
通讯作者：
Lu An-xian
作者机构：
[Lu An-xian; Gao Chao; Ouyang Xue-qiong; Long Wo-yun] Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Long Wo-yun] Hunan Agr Univ, Dept Appl Phys, Changsha 410083, Hunan, Peoples R China.;[Bian Jian-ze] Barun Min Co Ltd, Baotou 014080, Peoples R China.
通讯机构：
[Lu An-xian] C;Cent S Univ, Sch Mat Sci & Engn, Changsha 410083, Hunan, Peoples R China.
关键词：
Zr-based metallic glass;mechanical alloying;sintering;activation energy
摘要：
Zr50Al15Ni10Cu25 amorphous powder was synthesized by mechanical alloying. The effect of Si3N4 addition on the crystallization behavior of the alloy during sintering process was studied. Thermal stability of the powders was performed by differential scanning calorimetry (DSC). The phase and microstructure of the powders and bulk specimens sintered were determined by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results show that, introducing 0.05% (mass fraction) Si3N4 can enhance the crystallization activation energy of the Zr50Al15Ni10Cu25 amorphous powders, which indicates that Si3N4 addition has hindrance effect on forming crystals from Zr50Al15Ni10Cu25 amorphous powder. However, 0.10% Si3N4 results in the decrease of the crystallization activation energy, which makes its crystallization process easy to occur.
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英文
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MULTIPLICITY OF SOLUTIONS FOR A FOURTH-ORDER IMPULSIVE DIFFERENTIAL EQUATION VIA VARIATIONAL METHODS
作者：
Sun, Juntao;Chen, Haibo* ;Zhou, Tiejun
期刊：
BULLETIN OF THE AUSTRALIAN MATHEMATICAL SOCIETY ,2010年82(3):446-458 ISSN：0004-9727
通讯作者：
Chen, Haibo
作者机构：
[Chen, Haibo; Sun, Juntao] 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] C;Cent S Univ, Dept Math, Changsha 410075, Hunan, Peoples R China.
关键词：
impulsive differential equation;boundary value problem;critical points;variational methods
摘要：
In this paper, we deal with the multiplicity of solutions for a fourth-order impulsive differential equation with a parameter. Using variational methods and a 'three critical points' theorem, we give some new criteria to guarantee that the impulsive problem has at least three classical solutions. An example is also given in order to illustrate the main results. Copyright © Australian Mathematical Publishing Association Inc. 2010.
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英文
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A note on the Lyapunov exponent in continued fraction expansions
作者：
Cheng, Jianzhong* ;Shen, Lu-Ming
期刊：
TURKISH JOURNAL OF MATHEMATICS ,2010年34(2):145-151 ISSN：1300-0098
通讯作者：
Cheng, Jianzhong
作者机构：
[Cheng, Jianzhong] PLA, Basis Dept Commun, Wuhan, Peoples R China.;[Cheng, Jianzhong] PLA, Commanding Coll, Wuhan, Peoples R China.;[Shen, Lu-Ming] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Cheng, Jianzhong] P;PLA, Basis Dept Commun, Wuhan, Peoples R China.
关键词：
Continued fractions;Levy constant;Hausdorff dimension
摘要：
Let T : [0, 1) --> [0, 1) be the Gauss transformation. For any irrational x is an element of [0, 1), the Lyapunov exponent alpha(x) of x is defined as alpha(x) = lim(n-->infinity) 1/n log |(T(n))'(x)|. By Birkoff Average Theorem, one knows that alpha(x) exists almost surely. However, in this paper, we will see that the non-typical set {x is an element of [0, 1) : lim(n-->infinity) 1/n log |(T(n))'(x)| does not exist} carries full Hausdorff dimension.
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英文
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Nonenzymatic glucose sensor based on gold–copper alloy nanoparticles on defect sites of carbon nanotubes by spontaneous reduction
作者：
Liu, Dengyou;Luo, Qimei* ;Zhou, Fuqiang
期刊：
Synthetic Metals ,2010年160(15-16):1745-1748 ISSN：0379-6779
通讯作者：
Luo, Qimei
作者机构：
[Luo, Qimei; Zhou, Fuqiang; Liu, Dengyou] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Luo, Qimei] H;Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
关键词：
Glucose detection;Functional carbon nanotubes;Spontaneous reduction;Catalysis
摘要：
Gold (Au) and copper (Cu) alloy catalysts were deposited on the defect sites of carbon nanotubes by spontaneous reduction among AuCl<inf>4</inf> <sup>-</sup>, Cu<sup>2+</sup> and oxygen-containing functional groups. Compared with AuCu alloy catalysts prepared by adsorption methods and electrochemical deposition methods, AuCu alloy catalysts show excellent catalytic ability to glucose by spontaneous reduction. The linear range of nonenzymatic sensors that were prepared by spontaneous reduction for glucose detection is 0.08-9.26 mM, and detection limit is 4 μM. In addition, there are high sensitivity (22 μA mM<sup>-1</sup>), reproducibility (96%) and stability (95% after 60 days). Selectivity of this nonenzymatic sensor for ascorbic, uric acid and acetaminophen was also obtained. ©2010 Elsevier B.V.
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英文
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Conductive three-dimensional ordered nano-gold film: Ultrasensitive electrochemical sensing platform for clinical immunoassay
作者：
Liu, Dengyou;Gao, Zhixi;Luo, Qimei;Wu, Zai-Sheng*
期刊：
Talanta ,2010年82(4):1175-1180 ISSN：0039-9140
通讯作者：
Wu, Zai-Sheng
作者机构：
[Luo, Qimei; Liu, Dengyou] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Wu, Zai-Sheng] Hunan Univ, Coll Chem & Chem Engn, State Key Lab Chemo Biosensing & Chemometr, Changsha 410082, Hunan, Peoples R China.;[Gao, Zhixi] Zunyi Normal Coll, Dept Chem, Zunyi 563002, Guizhou, Peoples R China.
通讯机构：
[Wu, Zai-Sheng] H;Hunan Univ, Coll Chem & Chem Engn, State Key Lab Chemo Biosensing & Chemometr, Changsha 410082, Hunan, Peoples R China.
关键词：
Antibody;Human immunoglobulin G;Three-dimensional ordered nano-gold film;Ultrasensitive electrochemical clinic immunoassay
摘要：
A simple, reusable and ultrasensitive electrochemical clinic immunoassay is proposed via developing a versatile CTDONG (conductive three-dimensional ordered nano-gold) film-modified gold electrode, in which ferrocene derivative and human immunoglobulin G (hIgG) are used as signaling probe and model molecule, respectively. A signal-on signaling mechanism is achieved by utilizing a sandwich format of the primary antibody/hIgG/the secondary antibody labeled with Ferrocene (PAb/Ag/SAb). Owing to the combination of the advantages of CTDONG film with the versatility of ferrocene derivatives, a substantially enhanced signal accompanied by a low background peak current is achieved. By this sensing scheme, target molecule can be readily quantified in a comparatively wide dynamic range (8.1 ×10<sup>-13</sup>-6.2 ×10<sup>-10</sup> M) with a relatively low detection limit (2.7 ×10 <sup>-13</sup> M). In addition to a greatly improved signal gain, this immunosensor gives a favourable reusability and good reproducibility. Moreover, the CTDONG film-based sensing interface shows excellent anti-interference ability to the coexistent proteins. Meanwhile, the recovery test and determination of target molecule in real samples have confirmed the feasibility of designed sensing system for clinic immunoassay of protein molecules, demonstrating the potential application of described CTDONG film in the development of biomolecule assay platforms. ©2010 Elsevier B.V. All rights reserved.
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英文
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Some metric properties on the GCF fraction expansion
作者：
Shen, Luming* ;Zhou, Yuyuan
期刊：
Journal of Number Theory ,2010年130(1):1-9 ISSN：0022-314X
通讯作者：
Shen, Luming
作者机构：
[Shen, Luming; Zhou, Yuyuan] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Shen, Luming] H;Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
关键词：
GCF fraction;Partial quotients;Metric properties
摘要：
In Schweiger (2003) [1], Fritz Schweiger introduced the algorithm of the generalized continued fraction (GCF), and in Zhong (2008) [2]. 1 Zhong studied some basic metric properties of the GCF. In this paper, under the restriction of -1 < epsilon(k) <= 1, the "0-1" law and the central limit theorem Of quotients in the GCF expansions are studied. (C) 2009 Elsevier Inc. All rights reserved.
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英文
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On analytic formulas of Feynman propagators in position space
作者：
Zhang Hong-Hao* ;Feng Kai-Xi;Qiu Si-Wei;Zhao An;Li Xue-Song
期刊：
中国物理C ,2010年34(10):1576-1582 ISSN：1674-1137
通讯作者：
Zhang Hong-Hao
作者机构：
[Zhao An; Qiu Si-Wei; Zhang Hong-Hao; Feng Kai-Xi] Sun Yat Sen Univ, Sch Phys & Engn, Guangzhou 510275, Guangdong, Peoples R China.;[Li Xue-Song] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Zhang Hong-Hao] S;Sun Yat Sen Univ, Sch Phys & Engn, Guangzhou 510275, Guangdong, Peoples R China.
关键词：
Feynman propagator;Klein-Gordon field;Dirac field;arbitrary dimensional spacetime
摘要：
We correct an inaccurate result of previous work on the Feynman propagator in position space of a free Dirac field in (3 + 1)-dimensional spacetime; we derive the generalized analytic formulas of both the scalar Feynman propagator and the spinor Feynman propagator in position space in arbitrary (D + 1)-dimensional spacetime; and we further find a recurrence relation among the spinor Feynman propagator in (D+1)-dimensional spacetime and the scalar Feynman propagators in (D+1)-, (D-1)- and (D+3)-dimensional spacetimes. ©2010 Chinese Physical Society and the Institute of High Energy Physics of the Chinese Academy of Sciences and the Institute of Modern Physics of the Chinese Academy of Sciences and IOP Publishing Ltd.
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英文
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A further discussion of the Hausdorff dimension in Engel expansions
作者：
Shen, Lu-ming*
期刊：
ACTA ARITHMETICA ,2010年143(3):271-276 ISSN：0065-1036
通讯作者：
Shen, Lu-ming
作者机构：
[Shen, Lu-ming] Huazhong Univ Sci & Technol, Sch Math & Stat, Wuhan 430072, Hubei, Peoples R China.;[Shen, Lu-ming] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.
通讯机构：
[Shen, Lu-ming] H;Huazhong Univ Sci & Technol, Sch Math & Stat, Wuhan 430072, Hubei, Peoples R China.
关键词：
Engel expansion;partial quotients;Hausdorff dimension
摘要：
In [GA], the Engel expansion transformation of x E(0,1] was defined as Tx = di(x)x — 1, where di(x) = [1/x] + 1, and thepartial quotients {(x)}n>1 of the Engel expansion were defined by d(X) =di(Tn-1(X)).
语种：
英文
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Characterization of yeast cells as a microencapsulation wall material by Fourier-transform infrared spectroscopy
作者：
Shi, Guorong* ;Rao, Liqun;Xie, Qingji;Li, Jun;Li, Benxiang;...
期刊：
Vibrational Spectroscopy ,2010年53(2):289-295 ISSN：0924-2031
通讯作者：
Shi, Guorong
作者机构：
[Shi, Guorong; Xiong, Xingyao] Key Lab Hunan Crop Germplasm Innovat & Utilizat, Changsha 410128, Hunan, Peoples R China.;[Li, Jun; Shi, Guorong; Li, Benxiang] Hunan Agr Univ, Coll Sci, Changsha 410128, Hunan, Peoples R China.;[Rao, Liqun] Hunan Agr Univ, Coll Biosci & Biotechnol, Changsha 410128, Hunan, Peoples R China.;[Xie, Qingji] Hunan Normal Univ, Coll Chem & Chem Engn, Minist Educ China, Key Lab Chem Biol & Tradit Chinese Med Res, Changsha 410081, Hunan, Peoples R China.
通讯机构：
[Shi, Guorong] K;Key Lab Hunan Crop Germplasm Innovat & Utilizat, Changsha 410128, Hunan, Peoples R China.
关键词：
FT-IR spectroscopy;Multivariate analysis;S. cerevisiae;Chlorogenic acid;Microencapsulation
摘要：
The chemically induced structural changes of yeast cells as a wall material for the microencapsulation of chlorogenic acid (CGA) were investigated by the Fourier-transform infrared (FT-IR) spectroscopy. Results indicate that the encapsulation performance of S. cerevisiae cells was largely affected by the composition of the culture medium, and the optimal composition of the culture medium was obtained in terms of the encapsulation yield of CGA. The yeast cells cultured under optimal conditions were subject to chemical treatment by sodium chloride, cetyltrimethylammonium bromide (CTAB), Triton X-100, sodium dodecyl sulfate (SDS) or ethanol. The chemical treatments notably changed the encapsulation properties of S. cerevisiae cells for CGA, with the highest encapsulation yield in the CTAB case. All the chemical treatments decreased the FT-IR absorption bands for proteins and nucleic acids of S. cerevisiae cells but increased those for lipids and fatty acids, and it is thus rather difficult to discuss the relationship between the encapsulation yield and the wall structures derived from the original FT-IR spectra. In contrast, multivariate analyses on the second derivative transformation FT-IR spectra of the yeast cell wall materials indicate that under various culture and chemical treatment conditions, the encapsulation yield of yeast cells for CGA was positively correlated with its IR absorption ratios of 1157 cm<sup>-1</sup> to 1043 cm<sup>-1</sup> (D1157/D1043) and of 1537 cm<sup>-1</sup> to 1043 cm<sup>-1</sup> (D1537/D1043) significantly (p <0.05), whereas negatively correlated with those of 1080 cm<sup>-1</sup> to 1043 cm<sup>-1</sup> (D1080/D1043), 1458 cm<sup>-1</sup> to 1043 cm<sup>-1</sup> (D1458/D1043) and 1740 cm<sup>-1</sup> to 1043 cm <sup>-1</sup> (D1740/D1043) significantly (p <0.05). The five absorption ratios proposed here from the second derivative transformation FT-IR spectra may be a rapid gauge for predicting the encapsulation properties of yeast cells and screening out optimal yeast cells for encapsulation of other species. ©2010 Elsevier B.V. All rights reserved.
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英文
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