Soliton breathers in spin-1 Bose–Einstein condensates

We consider a spin-1 Bose-Einstein condensate trapped in a harmonic potential with different nonlinearity coeffi- cients. We illustrate the dynamics of soliton breathers in two-component and three-component states by numerically solv- ing the one-dimensional time-dependent coupled Gross-Pitaecskii equations （GPEs）. We present that two condensates with repulsive interspecies interactions make elastic collision and novel soliton breathers are created in two-component state. We also demonstrate novel soliton breathers in three-component state with attractive coupling constants. Furthermore, possible reasons for creating soliton breathers are discussed.

Kuznetsov–Ma soliton and Akhmediev breather of higher-order nonlinear Schrdinger equation

In terms of Darboux transformation, we have exactly solved the higher-order nonlinear Schr6dinger equation that describes the propagation of ultrashort optical pulses in optical fibers. We discuss the modulation instability （MI） process in detail and find that the higher-order term has no effect on the MI condition. Under different conditions, we obtain Kuznetsov-Ma soliton and Akhmediev breather solutions of higher-order nonlinear Schredinger equation. The former describes the propagation of a bright pulse on a continuous wave background in the presence of higher-order effects and the soliton＇s peak position is shifted owing to the presence of a nonvanishing background, while the latter implies the modulation instability process that can be used in practice to produce a train of ultrashort optical soliton pulses.

Peregrine Rogue Waves Generated by the Interaction and Degeneration of Soliton-Like Solutions: Derivative Nonlinear Schrödinger Equation

We study the Peregrine rogue waves within the framework of Derivative Nonlinear Schrödinger equation, which is used to describe the propagation of Alfven waves in plasma physics and sub-picosecond or femtosecond pulses in nonlinear optics. The interaction and degeneration of two soliton-like solutions and its relations for the breather solution have been analyzed. The Peregrine rogue waves have been considered from the two kinds of formation processes: it can be generated through the limitation of the infinitely large period of the breather solutions, and it can be interpreted as the soliton-like solutions with different polarities. As a special example, a special Peregrine rogue wave is generated by a breather solution and phase solution, which is given by the trivial seed (zero solution).

一个(3+1)-维KdV方程的呼吸子解、孤子解及形态转换

研究了一个(3+1)-维Korteweg-de Vries(KdV)方程的呼吸子解和孤子分子的共振条件。首先,借助Hirota双线性导数法对一个(3+1)-维KdV方程进行双线性化,利用双线性形式求出该方程的呼吸子解。然后,在一定参数条件下,呼吸子解可以转换为其他类型的非线性波形态,比如W型波、双峰孤波、平行孤波和周期孤波等。最后,求出(x,y)、(x,z)、(x,t)、(y,z)、(y,t)、(z,t)等平面上的孤子分子的共振条件,并进行了动力学分析。

非局域非线性介质中的拉盖尔-高斯涡旋呼吸子和涡旋光孤子

在圆柱坐标系下,利用分离变量的方法求得了非局域克尔介质中拉盖尔-高斯光束传输的精确解析解。当输入功率等于临界功率时,光束演变为拉盖尔-高斯涡旋光孤子,是一种旋转的多环光孤子;当输入功率接近于临界功率时,光束在传输过程中形成拉盖尔-高斯涡旋呼吸子。结果表明,低阶的拉盖尔-高斯孤子呈现中空多峰亮环分布。

(3+1)维非线性方程的呼吸类和周期类孤子解

对(3+1)维的非线性方程借助符号计算软件,运用拓展的三波法,获得了方程的三孤子解,周期双孤子解,呼吸类的周期孤子解和呼吸类的双孤子解.结果表明:对于寻求多维非线性发展方程的多波解,拓展的三波法已成为一个比较直接和有效的工具.

一维非线性单原子分立晶格振动的格孤波解和非传播呼吸子解

利用多重尺度方法和准分立方法,对一维非线性单原子分立晶格的振动方程进行求解,得到了其在布里渊区中心处和布里渊区边界上具有非传播的呼吸子解,而在晶格的其它处具有传播的包络孤子,亦即格孤波解.

氢键链中外场对扭结孤子和呼吸子的影响

利用导数展开法，分别研究了在氢键链中外场对于扭结孤子和呼吸子的影响，得到了孤子迁移率及其共振频率，并指出当外场频率ω０满足时，呼吸子发生相锁。当ω０＝ωＨ时，扭结孤子作共振运动．

一维单原子链非线性振动的孤子解和呼吸子解

运用连续极限近似,求解一维单原子链的非线性振动方程,得到了一维单原子晶格振动的孤子解,在考虑三次非简谐势的情况下,一维单原子链晶格振动具有扭结孤子解,在考虑具有四次非简谐势的情况下,得到一维单原子链晶格振动具有呼吸子解。

时空调制光子晶格中的空间光孤子（英文）

采用自相似方法,时空调制的光子晶格广义变系数的非线性薛定谔方程化简为常系数方程,将相关的表达式代入原方程,得到了不同传播形式的精确孤子解,并详细讨论了周期性分布的亮、暗呼吸子的传输性质.

Impurity-induced localization of Bose-Einstein condensates in one-dimensional optical lattices

The impurity-induced localization of two-component Bose-Einstein condensates loaded into deep one-dimensional optical lattices is studied both analytically and numerically. It is shown that, the analytical criteria for self-trapping and moving soliton/breather of the primary-component condensate are modified significantly by an admixture of an impurity component （the second component）. The realization of the self-trapped state and the moving soliton/breather states of the primary-component becomes more easy with the minor admixture of the impurity-component, even if the two components are partly overlapped.

Explicit Breather-Type and Pure N-Soliton Solution of DNLS^+ Equation with Nonvanishing Boundary Condition

Based on a newly revised inverse scattering transform for the derivative nonlinear SchrSdinger （DNLS＋） equation with nonvanishing boundary condition （NVBC）, the explicit breather- type and pure N-soliton solution has been derived by some algebra techniques. The two-breather solution and the pure double-soliton solution have been given as two typical examples in illustration of the general formula of the multi-soliton solution. The asymptotic behaviors of the N-soliton solution are discussed in detail.

mKdV方程的呼吸孤立子解

采用普遍用来求解非线性演化方程解析解的行波法求解在等离子体物理中得以广泛应用的mKdV方程,得到mKdV方程的一种特殊孤立子解-呼吸孤立子解,并用图形对呼吸孤立子的主要特征予以展示.

Abundant Lump Solutions and Interaction Phenomena to the Kadomtsev-Petviashvili-Benjamin-Bona-Mahony Equation

In this paper, we obtained a kind of lump solutions of the Kadomtsev-Petviashvili-Benjamin-Bona-Mahony (KP-BBM) equation with the assistance of Mathematica. Some contour plots with different determinant values are sequentially made to show that the corresponding lump solutions tend to zero when x2+y2→∞. Particularly, lump solutions with specific values of the include parameters are plotted, as illustrative examples. Finally, a combination of stripe soliton and lump soliton is discussed to the KP-BBM equation, in which such a solution presents two different interesting phenomena: lump-kink and lump-soliton. Simultaneously, breather rational soliton solutions are displayed.

Sine-Gordon Solitons and Breathers in Rod-like Magnetic Liquid Crystals under External Magnetic Field

To study the nonlinear phenomena in rod-like magnetic liquid crystals(RMLCs), this paper establishes the dynamic model of molecular motion when giving a twisting disturbance to the molecules under external magnetic field.We find the twist of the molecules under magnetic field can be propagated in the form of a traveling wave. The dynamic equation of the molecular twisting we derived satisfies the form of Sine-Gordon equation. We obtain two solutions of the Sine-Gordon equation by theoretical calculation: the kink and anti-kink solitons and breathers. The characteristics of those solitons and breathers are discussed.

(2+1)维Ito方程的孤子解和有理解

基于Hirota双线性方法,得到(2+1)维Ito方程的双线性形式,由此可以求得(2+1)维Ito方程的N-孤子解.在二孤子解的基础上,对参数取共轭,可以得到一阶的呼吸子解;再对二孤子解用长波极限和参数限制,则可以得到Ito方程的一阶有理解.

(2+1)-维5阶KdV方程的相互作用解

使用Hirota双线性方法求出(2+1)-维5阶Kd V方程的单孤子解、呼吸子解、Lump孤子解,并且通过理论计算的方法得到Lump型孤子的运动轨迹、有效体积、有效动能等动力学特征量,然后通过单孤子解与呼吸子解的叠加方式发现呼吸子被单孤子吞噬的现象,以及探究Lump型孤子与单孤子的相互作用过程中所表现出来的碰撞、反弹、吸收、分裂等粒子性特征,从而揭示现象背后所反映出来的物理学规律。

Transcription's bubble under the influence of long-range interactions and helicoidal coupling

The influence of power-low long-range interactions （LRI） and helicoidal coupling （HC） on the properties of localized solitons in a DNA molecule when a ribonucleic acid polymerase （RNAP） binds to it at the physiological temperature is analytically and numerically investigated in this paper. We have made an analogy with the Heisenberg model Hamiltonian of an anisotropic spin ladder with ferromagnetic legs and anti-ferromagnetic rung coupling. When we limit ourselves to the second-order terms in the Taylor expansion, the DNA dynamics is found to be governed by a completely integrable nonlinear Schr？dinger （NLS） equation. In this case, results show that increasing the value of HC force or LRI parameter enhances the bubble height and reduces the number of base pairs which form the bubble. For the fourth-order terms in a Taylor expansion, results are closely resembling those of second-order terms, and are confirmed by numerical investigation. These results match with some experimental data and thus provide a better representation of the base pairs opening in DNA which is essential for the transcription process.

Localized waves of the coupled cubic–quintic nonlinear Schrdinger equations in nonlinear optics

We investigate some novel localized waves on the plane wave background in the coupled cubic-quintic nonlinear Schrdinger （CCQNLS） equations through the generalized Darboux transformation （DT）. A special vector solution of the Lax pair of the CCQNLS system is elaborately constructed, based on the vector solution, various types of higher-order localized wave solutions of the CCQNLS system are constructed via the generalized DT. These abundant and novel localized waves constructed in the CCQNLS system include higher-order rogue waves, higher-order rogues interacting with multi-soliton or multi-breather separately. The first-and second-order semi-rational localized waves including several free parameters are mainly discussed：（i） the semi-rational solutions degenerate to the first-and second-order vector rogue wave solutions; （ii） hybrid solutions between a first-order rogue wave and a dark or bright soliton, a second-order rogue wave and two dark or bright solitons; （iii） hybrid solutions between a first-order rogue wave and a breather, a second-order rogue wave and two breathers. Some interesting and appealing dynamic properties of these types of localized waves are demonstrated, for example, these nonlinear waves merge with each other markedly by increasing the absolute value of α. These results further uncover some striking dynamic structures in the CCQNLS system.

非局域耦合带有自PT对称Schrdinger方程的N重达布变换

目前,关于非线性薛定谔方程的研究工作取得了巨大的成果,然而对于PT对称的非局域耦合薛定谔方程所做的研究比较少.主要研究非局域耦合薛定谔方程,我们从3×3 Lax对出发,利用达布变换的方法,得到新解与旧解之间的关系.经过复杂的计算,得到1-孤子解,2-孤子解以及N-孤子解计算公式.最后,利用画图软件,得到一些孤子演化图,其中包括亮孤子波解,呼吸波解和怪波.同时,显示了两孤子之间的弹性相互碰撞,它们的振幅在相互作用后,除了相移之外保持不变.