Moving Compacton—like Kink in a Purely Anharmonic Lattice with Symmetric On—Site Potential

We study the moving compacton-like kink in the system of a purely anharmoinc lattice with symmetric onsite poential by a direct algebraic method.It is found that the localization of the compactons is related to the nonlinear coupling parameter Cnl and the potential barrier height V0 of the double well potential,and the velocity of the propagation of the compacton is determined by the localization parameter q and the potential barrier height V0.Numerical calculation results demonstrate that the compacton is stable when it moves along the lattice chain.     

Propagation and collision of compacton-like kinks in Klein—Gordon lattice system

We study the propagation and collision of the compacton-like kinks in the system of an anharmonic lattice with a double well on-site potential by a direct algebraic method and numerical experiments. It is found that the localization of the compacton-like kinks is related to the nonlinear coupling parameter Cnl and the potential barrier height V0 of the double well potential. The velocity of the propagation of the compacton-like kinks is determined by the linear coupling parameter Cl, the nonlinear coupling parameter Cnl and the localization parameter q. Numerical experiments demonstrate that appropriate Cl is not detrimental to a stable propagation of the compacton-like kinks. However, the collision of compacton-like kinks and anti-kinks in the lattice with comparatively small Cl leads to the emergence of a discrete stationary breather and small amplitude nonlinear oscillation background, while moderate Cl results in the emergence of two deformed kinks with radiating oscillations and lower propagation velocities.     

Synthesis of superconductor MgCNi3 with carbon nanotubes

MgCNi3, an intermetallic compound superconductor with a cubic perovskite crystal structure, has been synthesized using fine Mg and Ni powders and carbon nanotubes （CNTs） as starting materials by the conventional powder metallurgy method. The composition, microstructure and superconductivity are characterized using x-ray diffraction （XRD）, energy dispersive x-ray （EDX） analysis, scanning electron microscopy （SEM）, and superconducting quantum interference device （SQUID） magnetometer. The results indicate that the phases of the synthesized samples are MgCNi3 （major phase） and traces of C and MgO. The MgCNi3 particle sizes range from several hundreds of nanometres to several micrometres. The onset superconducting transition temperature Tc of the MgCNi3 sample is about 7.2 K. The critical current density Jc is about 3.44 × 10^4 A/cm^2 calculated according to the Bean model from the magnetization hysteresis loop of the slab MgCNi3 sample at 5 K and zero applied field.     

一维金刚石结构晶格的非线性局域模

用多重尺度法研究了质量均匀相互作用力交替变化的原子链形成的非线性局域振动模式,这 种原子链模拟了金刚石结构晶格沿〈111〉晶向或一维分子链的振动,通过多重尺度展开分 析得出,原子位移分布服从微扰的非线性Schrdinger方程,求得了相应的定态解和传播解 ,其结果与相互作用力相同质量交替分布的另一种形式的一维双原子晶格的结果有所不同, 其原因是金刚石结构晶格的对称性相对差些. 关键词： 金刚石结构 非线性局域模 多重尺度法     

Evolution of soliton-like train in Klein--Gordon lattice system

This paper studies the evolution of wave in the system of a pure anharmonic lattice with a double well on-site potential by numerical calculation. It finds that an initial distribution of static or moving wave can evolve into two travelling soliton-like trains with contrary directions and a region of oscillation in this lattice system. It presents that some cases with cosine-square-shape and Gaussian-shape initial distribution of static or moving wave will produce ordered soliton-like train. Careful numerical observation shows that the centre oscillation region in this system may act as a resource of generating soliton-like train.