Exotic interactions between solitons of the （2＋1）-dimensional asymmetric Nizhnik-Novikov-Veselov system

Starting from the extended tanh-function method (ETM) based on the mapping method, the variable separation solutions of the (2+1)-dimensional asymmetric Nizhnik--Novikov--Veselov (ANNV) system are derived. By further study, we find that these variable separation solutions are seemingly independent of but actually dependent on each other. Based on the variable separation solution and by choosing appropriate functions, some novel and interesting interactions between special solitons, such as bell-like compacton, peakon-like compacton and compacton-like semi-foldon, are investigated.     

Non-completely elastic interactions in a （2＋1）-dimensional dispersive long wave equation

With the help of a modified mapping method,we obtain two kinds of variable separation solutions with two arbitrary functions for the(2+1)-dimensional dispersive long wave equation.When selecting appropriate multi-valued functions in the variable separation solution,we investigate the interactions among special multi-dromions,dromion-like multi-peakons,and dromion-like multi-semifoldons,which all demonstrate non-completely elastic properties.     

New exact solutions of (3+1)-dimensional Jimbo-Miwa system

By using the (G'/G)-expansion method and the variable separation method, a new family of exact solutions of the (3+1)-dimensional Jimbo-Miwa system is obtained. Based on the derived solitary wave solutions, we obtain some special localized excitations and study the interactions between two solitary waves of the system.     

New exact solutions of a （3＋1）-dimensional Jimbo-Miwa system

By using the (G'/G)-expansion method and the variable separation method, a new family of exact solutions of the (3+1)-dimensional Jimbo-Miwa system is obtained. Based on the derived solitary wave solutions, we obtain some special localized excitations and study the interactions between two solitary waves of the system.     

(2+1)维色散长波方程的新精确解及其复合波激发

利用Riccati方程展开法和变量分离法,得到了(2+1)维色散长波方程的变量分离解.根据得到的孤波解,构造出该方程新颖的复合波局域结构,研究了复合波随时间的演化.     

Quasi-Periodic Structures Based on Symmetrical Lucas Function of(2+1)-Dimensional Modified Dispersive Water-Wave System

By introducing the Lucas--Riccati method and a linear variable separationmethod, new variable separation solutions with arbitrary functions arederived for a (2+1)-dimensional modified dispersive water-wave system. Themain idea of this method is to express the solutions of this system aspolynomials in the solution of the Riccati equation that the symmetricalLucas functions satisfy. From the variable separation solution and byselecting appropriate functions, some novel Jacobian elliptic wave structurewith variable modulus and their interactions with dromions and peakons are investigated.     

Periodic Semifolded Solitary Waves for （2＋1）-Dimensional Variable Coefficient Broer-Kaup System

Applying the extended mapping method via Riccati equation, many exact variable separation solutions for the （2＆1 ）-dimensional variable coefficient Broer-Kaup equation are obtained. Introducing multiple valued function and Jacobi elliptic function in the seed solution, special types of periodic semifolded solitary waves are derived. In the long wave limit these periodic semifolded solitary wave excitations may degenerate into single semifolded localized soliton structures. The interactions of the periodic semifolded solitary waves and their degenerated single semifolded soliton structures are investigated graphically and found to be completely elastic.     

New Exact Solutions and Localized Structures for （3＋1）-Dimensional Burgers System

With an extended mapping approach and a linear variable separation method, new families of variable separation solutions （including solitary wave solutions, periodic wave solutions, and rational function solutions） with arbitrary functions for （3＋1）-dimensionai Burgers system is derived. Based on the derived excitations, we obtain some novel localized coherent structures and study the interactions between solitons.     

Interactions among special embed-solitons for the (3+1)-dimensional Burgers equation

With the help of a modified mapping method and a new mapping method, we re-study the (3+1)-dimensional Burgers equation, and derive two families of variable separation solutions. By selecting appropriate functions in the variable separation solution, we discuss the interaction behaviors among taper-like, plateau-type rings, and rectangle-type embed-solitons in the periodic wave background. All the interaction behaviors are completely elastic, and no phase shift appears after interaction.     

(2+1)维破裂孤子方程的多方孤子解及其混沌行为

利用投射方程法和变量分离法,得到(2+1)维破裂孤子方程的新显式精确解. 根据得到的孤立波解,利用 Weierstrassp 函数,构造出多方孤子局域结构. 利用两个混沌系统研究了破裂孤子方程的混沌行为. 关键词： 投射方程法 破裂孤子方程 多方孤子 混沌行为     

Two-dimensional model for mixtures of enantiomers,bent hard needles: a Monte Carlo simulation

We study the statistical mechanical conditions under which segregation of racemic mixtures of chiral molecules is possible in a two-dimensional fluid model. Motivated by experimental evidence indicating that chiral hydrophilic heads of amphiphilic molecules lying in a monolayer can crystallize undergoing a chiral phase separation, we propose a two-dimensional system to model the projection of the chiral head of amphiphilic molecules in a monolayer. The molecules of our model are infinitely hard and infinitely thin. We consider interactions with only a repulsive contribution where molecules have no effective area (two-dimensional volume). As a consequence all effects found are due to excluded area. The Monte Carlo Gibbs ensemble is used to study phase separation whereas constant pressure simulations are performed to obtain equations of state of pure and racemic systems. We find that for this simple model segregation is generally possible in the very high density regime.     

(3+1)维Burgers系统的瞬内嵌孤子和瞬锥形孤子

利用投射方程法和变量分离法,得到了(3+1)维Burgers系统的变量分离解(包括孤波解、周期波解和有理函数解).根据孤波解和有理函数解,构造出Burgers系统新颖的局域结构,例如瞬内嵌孤子和瞬锥形孤子.     

Chiral separation in microflows

Molecules that only differ by their chirality, so-called enantiomers, often possess different properties with respect to their biological function. Therefore, the separation of enantiomers presents a prominent challenge in molecular biology and has long been a main pursuit of organic chemistry. We suggest a new separation technique for chiral molecules that is based on the transport properties in a microfluidic flow with spatially variable vorticity. Because of their size the thermal fluctuating motion of the molecules must be taken into account. These fluctuations play a decisive role in the proposed separation mechanism.     

Towards the origin of effective An(III)/Ln(III) separation by tridentate N-donor ligands: a theoretical study on atomic charges and polarisabilities for Cm(III)/Gd(III) separation

Soft N-donor ligand have shown to separate An(III) from Ln(III). The origin of the selectivity has not been entirely identified, and similar ligands show very different separation qualities. In this study we present a theoretical investigation of several relevant N-donor ligands in terms of atomic charges and polarisabilities obtained from an atoms in molecules approach. These allow new insights into the bonds between the ligands’ nitrogen atoms and the metal cation and explain a major part of the selectivity towards actinide ions. We deduct the superiority of 2,6-bis(1,2,4-triazine-3-yl)pyridines in separation quality compared to similar ligands for the Cm(III)/Gd(III) separation. Furthermore, improvements of existing ligands are developed that allow not only a direct experimental confirmation but also a systematic experimental study of the interactions and their influence on the selectivity.     

Interaction Behaviors Between Special Dromions in the(2+1)-Dimensional Broer-Kaup-Kupershmidt Equation

A modified mapping method is used to obtain variable separation solution with two arbitrary functions of the(2+1)-dimensional Broer-Kaup-Kupershmidt equation.Based on the variable separation solution and by selecting appropriate functions,we discuss the completely elastic head-on collision between two dromion-lattices,non-completely elastic "chase and collision" between two multi-dromion-pairs and completely non-elastic interaction phenomenon between anti-dromion and dromion-pair.     

(2+1)维破裂孤子方程的多 Solitoff 解及其演化

借助计算机 Maple 软件系统,利用拓展的(G'/G)方法和变量分离方法, 得到(2+1)维破裂孤子方程的精确解. 根据得到的孤立波解, 构造出多 Solitoff 局域结构, 研究了孤子随时间的演化.     

Soliton Fusion and Fission Phenomena in the (2+1)-Dimensional Variable Coefficient Broer-Kaup System

In this paper, the general projective Riccati equation method is applied to derive variable separation solutions of the (2+1)-dimensional variable coefficient Broer-Kaup system. By further studying, we find that these variable separation solutions obtained by PREM, which seem independent, actually depend on each other. Based on the variable separation solution and choosing suitable functions p and q, new types of fusion and fission phenomena among bell-like semi-foldons are firstly investigated.     

惰性气体氦、氖、氩原子与氢(氘、氚)分子碰撞截面的理论计算

原子分子相互作用在许多物理过程中都十分重要.原子分子碰撞过程中转动激发截面的研究是确定原子与分子间相互作用的理想方法,许多理论和实验工作者在这方面做了大量工作,并得到理论和实验数据.本文用密耦近似计算了惰性气体He、Ne、Kr与h2、D2、T2碰撞的弹性和转动激发截面,原子入射能量分别为0.05 eV、0.15eV、0.20eV和0.25eV.     

Modelling the interaction in a benzene dimer

The interaction between aromatic rings is a fundamental problem in material science and biochemistry. These interactions are generally found to stabilise protein molecules and the double helical structure of DNA, and they also play an important role in the recognition processes in biological and non-biological systems. However, the complexity and variety in the structures and components of aromatic compounds are major obstacles to investigating their interactions. In this study, the simplest case of aromatic interactions, which is the interaction between two benzene rings, is modelled using a continuous approximation. Assuming a constant atomic surface density and modelling the structure of a benzene molecule as a combination of two rings, namely an inner carbon ring and an outer hydrogen ring, the van der Waals interaction between any two benzene rings can be obtained as the sum of four interactions. The major result obtained here is an analytical expression for the potential energy which can then be used to predict equilibrium configurations for two interacting benzene molecules. Moreover, we find that at sufficiently large distances between the two benzene molecules, the orientational angle φ at which the interaction energy is a minimum can be approximated by the arctan of the ratio of two separation distances in two mutually perpendicular directions.     

Nonpropagating Solitary Waves in (2+1)-Dimensional Nonlinear Systems

By means of extended homogeneous balance method and variable separation approach, quite a general variable separation solution of the (2+1)-dimensional Broer-Kaup-Kupershmidt equation is derived. From the variable separation solution and by selecting appropriate functions, a new class of (2+1)-dimensional nonpropagating solitary waves are found. The novel features exhibited by these new structures are first revealed.