The Interaction of Peregrine Solitons

We theoretically investigate the interaction of two in-phase and out-of-phase Peregrine sofitons in a Kerr nonlinear medium, addressing both the cases of first- and second-order solitons. Upon adjusting the interval between the sofitons, their interactions exhibit different properties. If the interval is sufficiently large, two Peregrine sofitons will propagate individually and will not interact each other. However, if the interval is not very large, the Peregrine solitons will strongly interact and display varying behavior.     

超细碳酸钙微球的制备

采用乳状液膜与共沉淀结合法制备超细碳酸钙微球,考察了不同反应条件对碳酸钙形貌的影响。获得的试样使用X-射线衍射(XRD)、场发射扫描电镜(FESEM)、红外光谱(FT-IR)以及激光粒度仪等手段予以表征。结果表明,吐温-80和PVP的添加量分别为4 mL和0.5 g时,制备出了颗粒大小约为5μm的碳酸钙微球;碳酸钙材料的物相组成和形貌与溶液中吐温-80体积含量以及PVP含量密切相关。     

两个新型氮氧自由基及其配合物的合成、晶体结构和磁性

合成并表征了两种新的含有酰氨基取代的氮氧自由基配体L1和L2。将L1和L2与六氟乙酰丙酮盐(Co(II), Ni(II),Mn(II))配位得到五个新的单核金属配合物L1Co(hfac)2, L1Ni(hfac)2, L2Co(hfac)2,L2Ni(hfac)2和L2Mn(hfac)2。对L1和L2及其配合物的结构和磁性进行了表征，在配合物中氮氧自由基的氧和取代基羰基氧均和金属离子配位，自由基和金属离子之间存在着强的反铁磁相互作用。     

Isoscaling of the Fission Fragments with Langevin Equation

The Langevin equation is used to simulate the fission process of ^112Sn ^112Sn and ^116Sn ^116Sn. The mass distribution of the fission fragments are given by assuming the process of symmetric fission or asymmetric fission with the Gaussian probability sampling. The isoscaling behaviour has been observed from the analysis of fission fragments of both the reactions, and the isoscaling parameter α seems to be sensitive to the width of fission probability and the beam energy.     

Isoscaling Behaviour in the Isospin-Dependent Quantum Molecular Dynamics Model

The isoscaling behaviour is investigated in a frame of isospin-dependent quantum molecular dynamics models. The isotopic yields ratio Y2/Y1 for reactions ^48Ca ^48Ca and ^40 Ca ^4oCa at different entrance channels are simulated and presented, the relationship between the isoscaling parameter and the entrance channel is analysed, the results show that a and β reduce with the rise of incident energies and increase with the impact parameter b, which can be attributed to the temperature varying of the pre-fragments in different entrance channels. The relation of a and symmetry-term coefficient Csym reveals that the chemical potential difference △μ is sensitive to thesymmetry-term coefficient Csym, and raises with the increasing Csym.     

Dynamical Convergence Trajectory in Networks

It is well known that topology and dynamics are two major aspects to determine the function of a network. We study one of the dynamic properties of a network： trajectory convergence, i.e. how a system converges to its steady state. Using numerical and analytical methods, we show that in a logical-like dynamical model, the occurrence of convergent trajectory in a network depends mainly on the type of the fixed point and the ratio between activation and inhibition links. We analytically proof that this property is induced by the competition between two types of state transition structures in phase space： tree-like transition structure and star-like transition structure. We show that the biological networks, such as the cell cycle network in budding yeast, prefers the tree-like transition structures and suggest that this type of convergence trajectories may be universal.     

A Quasi-Symmetric Coupled Quantum Well and Its Electric-Optical Properties

We propose a novel coupled quantum well structure, i.e. a quasi-symmetric coupled quantum well (QSCQW). Based on the demands of optical switching devices for quantum well materials, the QSCQW configuration is further optimized. Consequently, in the case of low applied electric field 25kV/cm and low absorption loss 100cm^-1, a large field-induced refractive index change (for TE mode, n = 0.0106; for TM mode, n = 0.0115) is obtained in the QSCQW structure at the operation wavelength 1550hm. The value is in one or two order of magnitude larger than that in a rectangular quantum well and about 50% larger than that of five-step asymmetric coupled quantum well structure under the same working conditions. The refractive index change obtained with the optimized QSCQW under so low absorption loss and applied electric field is very attractive for semiconductor optical switching devices. This manifests that the QSCQW structure has a great potential for applications in ultra-fast and low-voltage optical switches and in travelling wave modulators.     

漫话数列压轴题

数列是高中数学的重要内容,又是学习高等 数学的基础,在历年的高考中占有重要的地位, 纵观近几年的高考,对数列知识点的考查,大多 是以一道选择题或填充题,一道解答题的形式出 现,有效地考查了学生的逻辑推理能力,运算能 力,以及运用相关知识分析问题、解决问题能力, 且在命题的方向上常与函数、方程、不等式等知 识进行有机的组合,使试题变得更具新意,能更 有效考查学生的思维品质和创新意识,试题也具 有较好的区分度. 一、要注重an与Sn的关系并把其作为 解题的突破口,来寻求数列压轴题的 解题途径. 　　案例1(2004年广西高…     

基于Delaunay三角法的电压门控钾离子通道的分类和拓扑结构识别

本文构建了一个Delaunay模型对电压门控钾离子(Kv)通道进行预测。该方法通过建立一系列带有隐含变量的单纯形来分类电压门控钾离子通道,然后通过未知序列在主成分空间里面的投影来预测结构。结果表明该模型无论是在分类和结构预测上均可以得到很好的结果。