New integrable hierarchies from vertex operator representations of polynomial Lie algebras

We give a representation–theoretic interpretation of recent discovered coupled soliton equations using vertex operators construction of affinization of not simple but quadratic Lie algebras. In this setup we are able to obtain new integrable hierarchies coupled to each Drinfeld–Sokolov of A, B, C, D hierarchies and to construct their soliton solutions.     

Structural and electronic properties of Bin (n = 2-14) clusters from density-functional calculations

The structural and electronic properties of Bi_n (n = 2-14) clusters have been systematically studied using gradient-corrected density-functional theory. For each cluster size, a number of structural isomers were constructed and optimized to search for the lowest-energy structure. The competition of several structural patterns such as cages, superclusters, and layered structures leads to the alternating appearance of these configurations as global minima. Although the tendency of Bi to form puckered-layer structures is already well-known, the electronic states of Bi_n clusters are still far from that of the bulk. As well, a remarkable even-odd atom number oscillation is observed in the structural and electronic properties of the clusters, implying that the stability of Bi_n clusters is mainly dominated by the electron shell effect rather than by geometrical packing. The theoretically calculated values for electron affinities agree well with available experimental data.     

海森堡模型中量子隐形传递的研究

通过对海森堡模型中量子热纠缠的研究,进而研究以海森堡热纠缠混合态为信道的量子隐形传递,计算出纠缠度和保真度,分析外界环境(温度、磁场等)对热纠缠及隐形传递的影响.     

Synthesis and photocatalytic activity of porous polycrystalline NiO nanowires

Porous polycrystalline NiO nanowires were prepared via thermal decomposition of the nickelous precursor synthesized via the hydrothermal reaction of nickel chloride with trisodium citrate dehydrate (C₆H₅Na₃O₇⋅2H₂O) in ethanol–H₂O binary solution. The porous polycrystalline nanowires with the diameters of 350 to 450 nm were constructed from NiO nanocrsystals with the cubic structure and the sizes of 8 to 12 nm. The photocatalytic activity of the as-prepared porous NiO nanowires for the degradation of acid scarlet dye was studied. It was found that their photocatalytic activity was stronger than that of NiO powders.     

中立型对数种群模型正周期解的存在性新结果

运用k-集压缩算子的拓扑度抽象连续定理,研究了如下一类高阶微分方程的周期解存在性问题x(m)(t)= r(t)-a(t)x(t-σ)-b(t)x(m)(t-τ).并将其应用于研究一类中立型对数种群模型dN/dt= N(t) [r(t)-a(t) In N(t-σ-b(t)d/(dt)In N(t-τ)]的正周期解存在性...     

Synchronization of chaotic delayed neural networks with impulsive and stochastic perturbations

In this paper, we study the exponential synchronization problem of a class of chaotic delayed neural networks with impulsive and stochastic perturbations. The involved time delays include time-varying delays and unbounded distributed delays. Employing the method of impulsive delay differential inequality, several new sufficient conditions ensuring the exponential synchronization are obtained, which can be easily checked by LMI Control Toolbox in Matlab. Compared with the previous methods, our method does not resort to complicated Lyapunov–Krasovkii, and the results derived are independent of the time-varying delays and do not require the differentiability of delay functions and the monotony of the activation functions. Finally, a numerical example and its simulation is given to show the effectiveness of the obtained results in this paper.     

A simple hydrothermal route to synthesis of rod-like MnOOH and spindle-shaped MnCO3

A simple hydrothermal route was developed to synthesis of rod-like manganese oxyhydroxide (MnOOH) and spindle-shaped manganese carbonate (MnCO₃) based on the redox reactions between potassium permanganate (KMnO₄) and ??-cyclodextrin (??-CD) without extra surfactant or template. At the mass ratio between ??-CD and KMnO₄ of 0.25, MnOOH nanorods with the diameter about 40?C400?nm and the length in the range of 2?C10???m could be facilely prepared in high yield. However, spindle-shaped MnCO₃ microparticles were prepared when the mass ratio between ??-CD and KMnO₄ was increased to 1.5. The as-prepared products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and high-resolution transmission electron microscopy. The formation mechanisms of rod-like MnOOH and spindle-shaped MnCO₃ were preliminarily discussed.     

Existence and asymptotic estimates of periodic solutions of El Nio mechanism of atmospheric physics

This paper is devoted to studying the El Nin o mechanism of atmospheric physics. The existence and asymptotic estimates of periodic solutions for its model are obtained by employing the technique of upper and lower solution, and using the continuation theorem of coincidence degree theory.     

The periodic solution to Nino-Southern the model for the El oscillation

A class of oscillator of the EI Nifio-Southern oscillation model is considered. Using Mawhin＇s continuation theorem, a result on the existence of periodic solutions for ENSO model is obtained.