Defect vector gap solitons in photonic lattices

The existence and general properties of different kinds of defect vector gap solitons in one dimensional optically induced photonic defect lattice with focusing saturable nonlinearity in photorefractive crystal are analyzed. The defect is well localized in a single site with two existence forms, namely repulsive and attractive defect. Propagation constants of two beams that compose defect vector gap solitons could be from same gap or from different gaps. We show that some kinds of unstable scalar defect gap solitons could be stabilized by their corresponding vector cases.     

Nonlinear charge transport mechanism in periodic and disordered DNA

We study a model for polaron-like charge transport mechanism along DNA molecules with emphasis on the impact of parametrical and structural disorder. Our model Hamiltonian takes into account the coupling of the charge carrier to two different kinds of modes representing fluctuating twist motions of the base pairs and H-bond distortions within the double helix structure of λ-DNA. Localized stationary states are constructed with the help of a nonlinear map approach for a periodic double helix and in the presence of intrinsic static parametrical and/or structural disorder reflecting the impact of ambient solvent coordinates. It is demonstrated that charge transport is mediated by moving polarons and breather compounds carrying not only the charge but also causing local temporal deformations of the helix structure through the traveling torsion and bond breather components illustrating the interplay of structure and function in biomolecules.     

ESR and ENDOR studies of solitons and polarons in conjugated polymers

Nonlinear excitations such as solitons and polarons in conjugated polymers carry spins. In this case electron spin resonance (ESR) and electron-nuclear double resonance (ENDOR) provide unique methods to determine their wave functions. In this review article, the case of solitons in polyacetylene, CH_x, and polarons in an electroluminescent polymer, poly(paraphenylene vinylene) (PPV) are discussed as typical examples. High-resolution proton ENDOR spectra, obtained with stretch-oriented samples, yield the half extension of the excitations of 18 carbon atoms and 4 phenyl rings for CH_x and PPV, respectively. These extensions are well described by the theories in the case of finite electron correlation. In addition, light-induced ESR technique is shown to be useful in obtaining site-selective information of spin distribution in the case of PPV derivatives, as well as the excitation spectra of polarons.     

Abundant different types of exact soliton solution to the (4+1)-dimensional Fokas and (2+1)-dimensional breaking soliton equations

The prime objective of this paper is to explore the new exact soliton solutions to the higher-dimensional nonlinear Fokas equation and(2+1)-dimensional breaking soliton equations via a generalized exponential rational function(GERF) method. Many different kinds of exact soliton solution are obtained, all of which are completely novel and have never been reported in the literature before. The dynamical behaviors of some obtained exact soliton solutions are also demonstrated by a choice of appropriate values of the free constants that aid in understanding the nonlinear complex phenomena of such equations. These exact soliton solutions are observed in the shapes of different dynamical structures of localized solitary wave solutions, singular-form solitons, single solitons,double solitons, triple solitons, bell-shaped solitons, combo singular solitons, breather-type solitons,elastic interactions between triple solitons and kink waves, and elastic interactions between diverse solitons and kink waves. Because of the reduction in symbolic computation work and the additional constructed closed-form solutions, it is observed that the suggested technique is effective, robust, and straightforward. Moreover, several other types of higher-dimensional nonlinear evolution equation can be solved using the powerful GERF technique.     

一水柠檬酸单晶的激光拉曼光谱

本文报道了一水柠檬酸在不同几何配置下的拉曼光谱。从一些谱峰的位移,各向异性及退偏振可以判断,晶体分子中存在较强的氢键。由CC,CO,CO谱线的频移等实验结果可以判断,由于氢键的影响,分子间的耦合及众多COO     

一水柠檬酸单晶的激光拉曼光谱

本文报道了一水柠檬酸在不同几何上的拉曼光谱。从一些谱峰的位移,各向异性及退偏振可以判断,晶体分子存在较中的氢键。由Ｃ－Ｃ,Ｃ－Ｏ,Ｃ＝Ｏ谱线的频移等实验结果可以判断,由于氢键的影响。分子间的耦合及从多ＣＯＯ＾－基团的电荷离域作用,使Ｃ－Ｃ,Ｃ－Ｏ单键带有部分双键的特性,而Ｃ＝Ｏ则带有部分单键的特点。     

C_8H_8O_7H_2O单晶的振动光谱

Ｃ８Ｈ８Ｏ７Ｈ２Ｏ单晶的振动光谱李丽霞（山东大学环境工程系济南２５０１００）ＴｈｅＶｉｂｒａｔｉｏｎａｌＳｐｅｃｔｒｕｍｏｆＣ８Ｈ８Ｏ７Ｈ２ＯＣｒｙｓｔａｌＬｉＬｉＸｉａ（ＥｎｖｉｒｏｎｍｅｎｔａｌＥｎｇｉｎｅｒｉｎｇＤｅｐａｒｔｍｅｎｔ，Ｓｈａｎｄ...     

Multipeaked polarons in a nonlinear lattice

Non-standard solutions for polarons in nonlinear lattices are investigated by analytical and numerical methods. These solutions represent polarons with several peaks in the envelope and are bound states of several solitons due to electron–phonon interactions.     

Non-linear transport by solitons in nanofibers of polymers in high magnetic field

Nonlinear local excitations like solitons, polarons, and bipolarons are known to be responsible for physical properties of conducting polymers. Recent experiments on nano-fibers in high electric and magnetic fields provide a further insight by demonstrating an effect of vanishing magnetoconductance (MC) in the polyacetylene (PA)—in contrast to other polymers. Here we present new experimental data and describe the theoretical model based on notion of solitons—dimerization kinks which can carry either the spin or the charge; they are allowed only in the PA with its degenerate ground state. The solitons experience a confinement force due to the interchange coupling which is erased by the electric field and disappears above critical field strength. The unbinding by tunneling allows for the transport of individual solitons, which sweeps off the spins residing at electronic intragap states associated with polarons, hence the vanishing MC.     

Surface superlattice solitons in nonlocal nonlinear media

We analyse surface solitons at the interface between a one-dimensional photonic superlattice and a uniform medium with weak nonlocal nonlinearity. We demonstrate that in deep lattices there exist three kinds of surface solitons when the propagation constant exceeds a critical value, including two on-site solitons and one off-site soliton. These three kinds of surface solitons have unique dynamical properties. If the relative depth of the superlattice is low, there is only one kind of off-site soliton; however, the solitons of this kind can propagate stably, unlike their deep superlattice counterparts. Dipole surface solitons are also investigated, and the stable domain is given.     

一类高对称结构碳布基球的键长和结合能

根据经验性模型势描述碳原子的相互作用，计算了一类高对称结构碳布基球键长和结合能，并初步分析了键长和结合能随布基球半径变化的规律 关键词：     

Evolution of dual-wavelength solitons in an erbium-doped fiber laser

We report on experimental observations of dual-wavelength solitons in a passively mode-locked erbium-doped fiber laser. Two kinds of dual-wavelength solitons with different spectrum shapes are achieved. One is exhibited to have spectrum sidebands and the other one is shown to have the smooth profile without any sideband. The mode-locking mechanism at different central wavelengths is analyzed. Experimental results suggest that the pump level together with the cavity filtering effect play key roles in the generation of the dual-wavelength solitons.     

Stability of elliptic vortex solitons in anisotropic nonlocal media

Elliptic vortex solitons are investigated in anisotropic nonlocal media with more general formulations. We address the existence and dynamics of such solitons analytically and numerically. The solution of elliptic vortex solitons depends on the eccentricity of both the input beam and nonlocal response function. With different degrees of nonlocality, we numerically investigate the evolution of the elliptic vortex solitons, and find that, typically, the elliptic vortex solitons with single and double charges collapse into spiraling dipole- and tripolelike soliton clusters, respectively.     

光折变明孤子的自偏转演化特性

利用一维稳态光折变空间光孤子的统一理论，研究了负载电阻对屏蔽、光伏和屏蔽光伏明孤子自偏转特性的影响。结果表明，无论加载电阻与否，这三种类型的光折变明孤子具有类似的自偏转特性，即孤子波沿一个抛物线轨迹运动。调节负载电阻可以改变孤子的偏转幅度，其中屏蔽光伏明孤子的可调范围最大。     

氢键分子系统的非线性激发和质子的传导特性

我们首先介绍了氢键系统的特性和质子在此系统中的运动特点及国际上对此问题研究的进展和存在的问题。接着较全面地描述我们提出的新理论的物理学基础、模型的特征和所形成的两类缺陷和质子孤子的特性。这个模型的最大特点是存在两类不同性质的非线性相互作用 ,它们之间的竞争和平衡导致了两类不同的缺陷和相应孤子的出现 ,这两类缺陷的协同和交替运动使质子在氢键系统中从一处传递到另一处。因此 ,此模型能完整地解释质子在氢键系统中的传递 ,在此基础上我们研究了重离子作非简谐振动和系统中存在的杂质及氢离子的迁移所产生的偶极矩等效应对质子孤子的影响以及在外场存在时 ,质子运动的特点 ,求出了质子在电场作用下的迁移率和传导率、大约分别为 (6 5 - 6 .9)× 1 0 - 6(m2 /v .s)和(7.6 - 8.1 )× 1 0 - 3/(Ωm) ,它刚好处在半导体范围内 ,与实验结果基本吻合。并且我们研究了质子传递的量子力学特性和质子孤子存在的临界温度     

Nonlinear polariton waves in an optical double lattice with photo-induced transport of atoms

The process of photo-induced transport of cold atoms in optical lattices is discussed for the case in which the direct tunneling of atoms is suppressed but transport of an atom is possible as a result of simultaneous absorption and reemission of two photons with different energies. Proceeding from the Bose-Hubbard model for two kinds of traps of a one-dimensional optical lattice, a set of equations describing the propagation of an ultrashort pulse of biharmonic radiation accompanied by a transfer of populations of traps of such a double lattice is derived. It was found that, depending on the choice of boundary conditions, there exist two types of stationary solitary waves corresponding to the propagation of a coupled pair of soliton pulses: a pair of bright solitons and a coupled pair of dark and bright solitons.     

Crystal field and molecular structure in solid C60

The crystal field in the orientationally disordered phase of C₉₀-fullerite is derived from an intermolecular potential model, which takes into account the geometric difference between double bonds and single bonds. The molecules are modelled as rigid bodies, atoms and single bonds are treated as single interaction centers, while double bonds are described by a distribution of interaction centers along the bond. The crystal field is expanded in terms of cubic rotator functions. The calculated expansion coefficients are compared with empirical values derived from diffraction data. The angular dependence of the crystal field, resulting from an anticlockwise rotation of the molecule around the [111] axis, exhibits an absolute and a secondary minimum at angles of 98° and 38° respectively. The self interaction of the molecule in a deformable lattice is investigated.     

N,N-二(8-羟基-5-喹啉甲基)甘氨酸乙酯的量子化学研究

运用分子轨道理论中的半经验AM1、PM 3方法和Hartree Fock从头算方法 ,通过能量梯度全优化率先计算了新近合成的化合物N ,N 二 (8 羟基 5 喹啉甲基 )甘氨酸乙酯的平衡几何构型、电子结构以及生成热、偶极矩等分子基本性质 ,并联系经典有机电子结构理论进行讨论。三种方法得到的结构参数基本一致 ,和实验测量的晶体结构符合较好。在稳定构型基础上 ,用AM1方法进行正则振动频率分析 ,得到C—C双键、C—N单双键、C—O单双键和羟基OH的振动基频 ,和实验测得的红外光谱特征峰吻合较好     

Soliton dynamical properties of Boseben Einstein condensates trapped in a double square well potential

We first present an analytical solution of the single and double solitions of Bose-Einstein condensates trapped in a double square well potential using the multiple-scale method. Then, we show by numerical calculation that a dark soliton can be transmitted through the square well potential. With increasing depth of the square well potential, the amplitude of the dark soliton becomes larger, and the soliton propagates faster. In particular, we treat the collision behaviour of the condensates trapped in either equal or different depths of the double square well potential. If we regard the double square well potential as the output source of the solitons, the collision locations (position and time) between two dark solitons can be controlled by its depth.     

Gray solitons in parity-time symmetric potentials

We numerically study the gray solitons in parity-time (PT) symmetric potentials. Simulated results show that there are two kinds of gray solitons, the dip-shaped gray solitons and the hump-shaped solitons, and both of them can be stable. Hump-shaped solitons can always exist, but the grayness of a stable dip-shaped gray soliton should exceed a threshold value. More interesting, it is discovered that when propagating in PT symmetric potentials, the gray solitons have no transverse deviation, and this is a phenomenon different from the usual gray solitons.