摘要:
We theoretically study the electron transport properties for two coupled single-walled carbon nanotube quantum dots connected to metallic electrodes under the irradiation of an external electromagnetic field at low temperatures. Using the standard nonequilibrium Green's function techniques, we examine the time-averaged transmission coefficient and linear conductance. It is shown that by some numerical examples, the photon-assisted inter-dot coupling causes Fano resonance and the conductance of the system is sensitive to the external field parameters. The transport dependence on the external field parameters may be used to detect the high-frequency microwave irradiation.
期刊:
MATCH-COMMUNICATIONS IN MATHEMATICAL AND IN COMPUTER CHEMISTRY,2008年59(1):171-190 ISSN:0340-6253
通讯作者:
Deng, Hanyuan
作者机构:
[Deng, Hanyuan] Hunan Normal Univ, Coll Math & Comp Sci, Changsha 410081, Hunan, Peoples R China.;[Chen, Shubo] Hunan City Univ, Dept Math, Yiyang 413000, Hunan, Peoples R China.
通讯机构:
[Deng, Hanyuan] H;Hunan Normal Univ, Coll Math & Comp Sci, Changsha 410081, Hunan, Peoples R China.
摘要:
The Hosoya index and the Merrifield-Simmons index of a graph are defined as the total numbers of its matchings and its independent sets, respectively. In this paper, we characterize the unicyclic graphs with extremal Hosoya indices and Merrifield-Simmons indices, respectively.
摘要:
A new method for protein separation by the gold nanotubules membrane based on the immunoreaction between antibody and antigen was described. The gold nanotubules can be electrolessly plated within the pores of polycarbonate nanoporous filtration membranes. The capture antibody, bovine IgG, was modified onto the inner wall of An nanotubules by glutaraldehyde interlinking method. The transport behaviour of detecting antibody through the nanotubules modified with capture antibody was investigated. When the diameter of the nanotubule was much larger than the size of the antibodies, there was no obvious difference between the transport rates for the proteins studied here through nanotubules. When the diameter of the nanotubule was ca. 30 nm, the transport of the goat anti-cat antibody through the nanotubules membrane was slow. Compared with goat anti-cat IgG, goat anti-bovine antibody transported through nanotubules membrane faster due to the immunoreaction between goat anti-bovine antibody and bovine IgG modified onto the pores of the membrane and the separation efficiency was 5.6. The results indicated that the gold nanotubule membranes showed good separating capability for protein without the loss of activity of the antibodies. (c) 2007 Published by Elsevier B.V.
摘要:
We propose a 5-D representation of DNA sequences based on the classifications of the four basic acid bases A,T,G, and C. The use of the 5-D representation is illustrated by constructing sequence invariants based on the entries in derived sequence matrices restricted to a selected width of a band along the main diagonal. As an application, we make a comparison for the first exon of beta-globin gene sequences belonging to eleven different species based on the 5-D representation.
期刊:
MATCH-COMMUNICATIONS IN MATHEMATICAL AND IN COMPUTER CHEMISTRY,2007年58(3):663-673 ISSN:0340-6253
通讯作者:
Chen, Shubo
作者机构:
[Chen, Shubo; Xia, Fangli] Hunan City Univ, Dept Math, Hunan 413000, Peoples R China.
通讯机构:
[Chen, Shubo] H;Hunan City Univ, Dept Math, Hunan 413000, Peoples R China.
摘要:
For a graph, the first Zagreb index M1 is equal to the sum of the squares of the degrees of the vertices, and the second Zagreb index M 2 is equal to the sum of the products of the degrees of pairs of adjacent vertices. This paper investigates the Zagreb indices of unicyclic graphs by introducing some transformations, and characterize the unicyclic graphs with the first five largest Zagreb indices and the unicyclic graphs with the first two smallest Zagreb indices, respectively.
摘要:
In this paper, the authors show a relation between the generalized convexity and super- (sub-)multiplicative property, and discuss some generalized convexity and inequalities involving the Gaussian hypergeornetric function, the generalized eta-distortion function eta(a)(K)(x) and the generalized Grotzsch function mu(a)(r). (c) 2007 Elsevier Inc. All rights reserved.
摘要:
A polymer electrolyte based on poly(vinylidene) fluoride-hexafluoropropylene was prepared by evaporating the solvent of dimethyl formamide, and non-woven fabric was used to reinforce the mechanical strength of polymer electrolyte and maintain a good interfacial property between the polymer electrolyte and electrodes. Polymer lithium batteries were assembled by using LiCoO2 as cathode material and lithium foil as anode material. Scanning electron microscopy, alternating current impedance, linear sweep voltammetry and charge-discharge tests were used to study the properties of polymer membrane and polymer Li-ion batteries. The results show that the technics of preparing polymer electrolyte by directly evaporating solvent is simple. The polymer membrane has rich micro-porous structure on both sides and exhibits 280% uptake of electrolyte solution. The electrochemical stability window of this polymer electrolyte is about 5.5 V, and its ionic conductivity at room temperature reaches 0.151 S/m. The polymer lithium battery displays an initial discharge capacity of 138 mA·h/g and discharge plateau of about 3.9 V at 0.2 current rate. After 30 cycles, its loss of discharge capacity is only 2%. When the battery discharges at 0.5 current rate, the voltage plateau is still 3.7 V. The discharge capacities of 0.5 and 1.0 current rates are 96% and 93% of that of 0.1 current rate, respectively.
作者机构:
[Zhong, WB] Hunan Univ, Coll Mat Sci & Engn, Changsha 410082, Peoples R China.;Hunan City Univ, Dept Mech, Yiyang 413000, Peoples R China.;Beijing Inst Chem Technol, Dept Polymer Sci, Beijing 100029, Peoples R China.
通讯机构:
[Zhong, WB] H;Hunan Univ, Coll Mat Sci & Engn, Changsha 410082, Peoples R China.
摘要:
Polypyrrole (PPy) nanowire networks have been synthesized in high yield (higher than 90%) by chemical oxidative polymerization of pyrrole in the presence of hexadecyltrimethylammonium bromide (HTAB) and organic diacids (oxalic acid, tartaric acid, or glutaric acid) and triacid (citric acid). The diameter of nanowire is 60−90 nm. The influence of reaction conditions, such as polymerization temperature, polymerization time, and the molar ratios of HTAB to organic acids and pyrrole, on the morphologies of the PPy nanowire networks has been systematically investigated. In addition, the interconnected PPy nanoparticles are prepared without using HTAB. The film of PPy nanowire networks and nanoparticles is superhydrophilic. A plausible formation mechanism of PPy nanowire networks is discussed.
摘要:
Summary: Polyaniline (PANI) nanowires and sub‐micro/nanostructured dendrites are synthesized and immobilized on PP‐g‐PAA film surfaces via routine oxidative polymerization of aniline under different conditions, where grafting poly(acrylic acid) (PAA) served as a template and dopant, and SDS as a surfactant. The immobilized PANI enhances the surface hydrophilicity of the poly(propylene) (PP) films, and a superhydrophilic surface is obtained in this way. The mechanism of forming different morphologies of PANI and of correspondingly obtaining a superhydrophilic surface are briefly discussed. FESEM image shows the PANI sub‐micro/nanostructured dendrites immobilized on the surfaces of PP films. The modified surface is highly hydrophilic with a water contact angle of 3°.
期刊:
Applied Mathematics and Computation,2006年177(1):105-110 ISSN:0096-3003
通讯作者:
Li, Fan-Liang
作者机构:
[Li, Fan-Liang] Hunan City Coll, Dept Math & Computat Sci, Yi Yang 413000, Peoples R China.;Hunan Univ, Coll Math & Econometr, Changsha 410082, Peoples R China.
通讯机构:
[Li, Fan-Liang] H;Hunan City Coll, Dept Math & Computat Sci, Yi Yang 413000, Peoples R China.
关键词:
skew-centrosymmetric matrix;left and right inverse eigenvalue;optimal approximation;EIGENVALUE PROBLEMS
摘要:
The left and right inverse eigenvalue problem of skew-centrosymmetric matrices and its optimal approximation are considered. New necessary and sufficient conditions for the solvability of the problem are derived, the general expression of the solution is given. The optimal approximate solution and some numerical experiments are also provided.
摘要:
The title compound, C40H36O5, was synthesized from p-anisaldehyde and acetophenone. The central six-membered ring adopts a chair conformation and most of the bulky side groups are located in equatorial positions. The hydroxyl group is involved in weak intra- and intermolecular hydrogen bonding.