Gannan Normal University

Ganzhou, China

Gannan Normal University

Ganzhou, China
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Xu X.,Beijing Normal University | Ye Z.,Beijing Normal University | Zhang Z.,Gannan Normal University
Applied Mathematics Letters | Year: 2015

In this paper we investigate the regularity criterion for the local in time classical solution to the 3D incompressible magnetohydrodynamic equations. We prove that if ∇×u belongs to L2(0,T;B∞, ∞-1), then the local solution (u,B) can be extended beyond time T. As a consequence, this result extends several previous works. © 2014 Elsevier Ltd. All rights reserved.


Chen D.,Gannan Normal University | Savidge T.,Baylor College of Medicine | Savidge T.,Texas Childrens Hospital
Science | Year: 2015

Fried et al. (Reports, 19 December 2014, p. 1510) demonstrate electric field-dependent acceleration of biological catalysis using ketosteroid isomerase as a prototypic example. These findings were not extended to aqueous solution because water by itself has field fluctuations that are too large and fast to provide a catalytic effect. Given physiological context, when water electrostatic interactions are considered, electric fields play a less important role in the catalysis.


Tang S.,Gannan Normal University | Zhang S.,Gannan Normal University
Journal of Physical Chemistry C | Year: 2011

The first-principles calculations have been used to investigate the structural and electronic properties of fluorographene nanoribbons and hybrid fluorographene-graphene nanoribbons. Our results indicate that both zigzag and armchair fluorographene nanoribbons are always semiconductors with width-dependent band gaps. The zigzag hybrid nanoribbons with F-terminated graphene edge are half-semiconductors with the two spin channels having a different band gap, qualitatively different from the graphene nanoribbons and hybrid graphane-graphene nanoribbons. The electronic properties of partially fluorinated zigzag graphene nanoribbons were well tuned by edge chemical modification and by control of the number of fluorinated zigzag carbon chains. With NH2 or CH3 groups passivating the graphene side edge, the half-metallicity in zigzag hybrid nanoribbons was realized. Interestingly, the partially fluorinated zigzag graphene nanoribbons with NH2 and CH3 groups may produce half-metallic → half-semiconducting behavior transition when the fluorographene widths gradually increase due to the chemical potential difference change. Therefore, fluorination of graphene nanoribbons will provide a novel way to tune the properties with potential applications to nanotechnology. © 2011 American Chemical Society.


Xiao X.,Gannan Normal University | Li Y.-L.,Jiangxi University of Science and Technology
European Physical Journal D | Year: 2013

Entangled states in high dimensional systems are of great interest due to the extended possibilities they provide in quantum information processing. Recently, Sun et al. [Phys. Rev. A 82, 052323 (2010)] and Kim et al. [Nat. Phys. 8, 117 (2012)] pointed out that weak measurement and quantum weak measurement reversal can actively combat decoherence. We generalize their studies from qubits to qutrits under amplitude damping decoherence. We find that the qutrit-qutrit entanglement can be partially retrieved for certain initial states when only weak measurement reversals are performed. However, we can completely defeat amplitude damping decoherence for any initial states by the combination of prior weak measurements and post optimal weak measurement reversals. The experimental feasibility of our schemes is also discussed. © EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2013.


Tang S.,Gannan Normal University | Cao Z.,Xiamen University
Physical Chemistry Chemical Physics | Year: 2012

Graphene oxides (GOs) may offer extraordinary potential in the design of novel catalytic systems due to the presence of various oxygen functional groups and their unique electronic and structural properties. Using first-principles calculations, we explore the plausible mechanisms for the oxidative dehydrogenation (ODH) of propane to propene by GOs and the diffusion of the surface oxygen-containing groups under an external electric field. The present results show that GOs with modified oxygen-containing groups may afford high catalytic activity for the ODH of propane to propene. The presence of hydroxyl groups around the active sites provided by epoxides can remarkably enhance the C-H bond activation of propane and the activity enhancement exhibits strong site dependence. The sites of oxygen functional groups on the GO surface can be easily tuned by the diffusion of these groups under an external electric field, which increases the reactivity of GOs towards ODH of propane. The chemically modified GOs are thus quite promising in the design of metal-free catalysis. © 2012 the Owner Societies.


Tang S.,Gannan Normal University | Zhang S.,Gannan Normal University
Journal of Physical Chemistry C | Year: 2013

The first-principles calculations have been used to investigate the electronic and magnetic properties of hybrid boron nitride nanoribbons (BNNR) and sheets, which are constructed by the B-rich or N-rich grain boundaries (GB) with the pentagon-heptagon (5-7) line defect joining together the normal zigzag and armchair BN segments. Our results show that, in contrast to the pristine BN systems, the hybrid BN nanostructures with 5-7 line defects possess some unique electronic and magnetic properties. The hybrid BNNR with H-passivated edge and BN sheet are semiconductors with notably reduced band gap due to the presence of line defect state, as compared to the normal BN systems. The band gaps of H-passivated hybrid BNNR with B-rich and N-rich GB exhibit the different variation with the ribbons width. The hybrid BNNR created by B-rich GB with bare N edge for all widths are half-semiconductors with the ferromagnetic ground state, whereas for the hybrid BNNR with bare zigzag B edge the antiferromagnetic → nonmagnetic semiconductor transition occurred when its narrow zigzag segment is changed to the wider one. Interestingly, totally different from the perfect zigzag BNNR, the hybrid BNNR with two-H-terminated B edge exhibit the metallic → half-semiconducting → half-metallic behavior transitions as its number of zigzag BN chains gradually increases due to the compressed zigzag edge. Therefore, the hybrid BN nanostructures constructed by GB with 5-7 line defects may provide potential applications for BN-based nanoelectronic and spintronic devices. © 2013 American Chemical Society.


Wang T.,Gannan Normal University
2010 International Conference on Intelligent Computation Technology and Automation, ICICTA 2010 | Year: 2010

This paper presents a new feature weighting method to improve the performance of support vector machine (SVM). The basic idea of this method is to translate the feature weight learning into the problem of choosing a kernel suitable for SVM classification. In more detail, this method tunes the width parameters of Gaussian ARD (Automatic Relevance Determination) kernel via optimizing a kernel evaluation criterion, i.e., kernel polarization. By using gradient ascent technique, each learned parameter indicates the relative importance of the corresponding feature. The proposed method is demonstrated with some UCI machine learning benchmark examples. © 2010 IEEE.


Zhang Z.,Gannan Normal University
Zeitschrift fur Angewandte Mathematik und Physik | Year: 2015

In this paper, we would like to improve the recent results of Yamazaki on the regularity criteria for the threedimensional magentohydrodynamic equations © 2014 Springer Basel.


Tang S.,Gannan Normal University | Cao Z.,Xiamen University
Journal of Physical Chemistry C | Year: 2012

The interactions of ammonia with graphene oxides (GO) were studied by density functional theory calculations. Our results indicate that the adsorption of NH 3 on GO is generally stronger than that on graphene because of the presence of diverse active defect sites, such as the hydroxyl and epoxy functional groups and their neighboring carbon atoms. These surface oxygen sites can form OH···N and O···HN hydrogen bonds with NH 3 and enhance charge transfers from NH 3 to the graphene oxide. The dissociation of the adsorbed NH 3 into the chemisorbed NH 2 or NH species through the H atom abstractions leads to hydroxyl group hydrogenation and ring-opening of epoxy group. The reactions of NH 3 with the hydroxyl and epoxy groups are predicted to be exothermic with different energy barriers, depending on the oxidation species and the atomic arrangement of these groups. The hydroxyl group exhibits relatively higher reactivity toward hydrogen abstraction from the adsorbed NH 3 than the epoxy group in GO with a single oxygen group. The presence of a neighboring OH group may activate the oxygen groups to facilitate the surface reaction of NH 3. Followed by the ring-opening of the epoxy group, the newly formed hydroxyl group can be removed by the second H atom abstraction from NH 2. The calculated density of states of the adsorbed systems also reveals strong interactions between GO and NH 3. The calculated results show good agreement with available experimental observations. © 2012 American Chemical Society.


Zhang Z.,Gannan Normal University
Zeitschrift fur Angewandte Mathematik und Physik | Year: 2015

This paper concerns about the Cauchy problem for the three-dimensional Navier–Stokes equations and provides a regularity criterion in terms of the gradient of one velocity component. This improves previous results. © 2015, Springer Basel.

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