A change in the rate of heterogeneous chemical reactions due to the presence of Toda solitons

It is demonstrated in this paper that an interesting application of Toda solitons could be as catalytical agents in chemical and biomolecular processes. Toda lattice modeling has been recently extended to proteins and in particular to DNA. We show here that the consequence of this approach would be a significant local lattice contraction. This, in turn, would result in an increase of the rate of chemical reactions for admolecules. Subsequently, two separate statistical treatments are used to estimate the relative change of the reaction rate. A comparison of the two results is provided, too.     

Spectrophotometric studies on the interaction between myricetin and lysozyme in the absence or presence of Cuor Fe

The binding of myricetin to lysozyme (Lys) in aqueous solution was investigated by fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy (UV) and circular dichroism (CD) spectra under physiological conditions. There are also many metal ions present in body, thus the research about the effect of metal ions on the interaction of drugs with proteins is crucial. In this study, we have investigated the effect of both familiar metal ions Cu²⁺ and Fe³⁺ on the interaction between myricetin and Lys by using spectroscopy technique at pH 7.40, for the first time. Spectrophotometric observations are rationalized in terms of a static quenching process in a static quenching way. The cause of showing upward curvy patterns in Stern-Volmer plots was analyzed. The binding constants and binding sites of myricetin with Lys with or without Cu²⁺ and Fe³⁺ at different concentrations of myricetin were calculated. UV/vis measurements on the enzymatic activity of Lys with or without Cu²⁺ in the absence or presence of myricetin indicated that the interaction between myricetin and Lys led to a reduction in the activity of Lys. Furthermore, the effect of pH on the binding constant of myricetin with Lys was also examined.     

From topological charge information to sets of solitons in quadratic non-linear media

We describe the principle of operation of a new class of optical devices operating in quadratic non-linear media that mix wave front topological charge dislocations nested in focused light beams and produce certain patterns of bright spatial solitons. Central to the device behaviour is the orbital angular momentum of the light beams.     

Hidden symmetry in the presence of fluxes

We derive the most general first-order symmetry operator for the Dirac equation coupled to arbitrary fluxes. Such an operator is given in terms of an inhomogeneous form ω   which is a solution to a coupled system of first-order partial differential equations which we call the generalized conformal Killing–Yano system. Except trivial fluxes, solutions of this system are subject to additional constraints. We discuss various special cases of physical interest. In particular, we demonstrate that in the case of a Dirac operator coupled to the skew symmetric torsion and U(1)$U(1)$ field, the system of generalized conformal Killing–Yano equations decouples into the homogeneous conformal Killing–Yano equations with torsion introduced in D. Kubiznak et al. (2009) [8] and the symmetry operator is essentially the one derived in T. Houri et al. (2010) [9]. We also discuss the Dirac field coupled to a scalar potential and in the presence of 5-form and 7-form fluxes.     

Critical theories of phase transition between symmetry protected topological states and their relation to the gapless boundary theories

Symmetry protected topological states (SPTs) have the same symmetry and the phase transition between them are beyond Landau?s symmetry breaking formalism. In this paper we study (1) the critical theory of phase transition between trivial and non-trivial SPTs, and (2) the relation between such critical theory and the gapless boundary theory of SPTs. Based on examples of SO(3)$\mathrm{SO}(3)$ and SU(2)$\mathrm{SU}(2)$ SPTs, we propose that under appropriate boundary condition the critical theory contains the delocalized version of the boundary excitations. In addition, we prove that the boundary theory is the critical theory spatially confined between two SPTs. We expect these conclusions to hold in general and, in particular, for discrete symmetry groups as well.     

Doped graphene: the interplay between localization and frustration due to the underlying triangular symmetry

An intuitive explanation of the increase in localization observed near the Dirac point in doped graphene is presented. To do this, we renormalize the tight binding Hamiltonians in such a way that the honeycomb lattice maps into a triangular one. Then, we investigate the frustration effects that emerge in this Hamiltonian. In this doped triangular lattice, the eigenstates have a bonding and antibonding contribution near the Dirac point, and thus there is a kind of Lifshitz tail. The increase in frustration is related to an increase in localization, since the number of frustrated bonds decreases with disorder, while the frustration contribution raises.     

浅海中孤立子内波引起的声能量起伏

当孤立子内波的波阵面与声传播路径所成角度较大时,简正波耦合是导致声信号起伏的主要因素。研究了浅海中孤立子内波引起的声能量起伏规律,给出声场起伏的耦合简正波表达式,并使用抛物方程模型进行仿真。数值分析表明,接收点声强随时间变化呈准周期性。在频谱图中能够得到声强起伏的主导频率,主导频率与孤立子内波沿声传播路径的移动速度成正比,与无扰动波导中简正波在距离上的干涉周期(对应于射线理论中临界声线的跨度)成反比,与孤立子内波的形状无关。此外,对声强频谱的垂直结构进行了分析,该结构与对声场起伏起主要作用简正波的本征函数相关。     

Sine-Gordon solitons in the presence of a noisy potential

We study the interaction of sine-Gordon solitons with two kinds of impurity potentials localized in space and varying randomly in time. the production of modified kink-antikink pairs is observed with different features depending respectively on the additive or multiplicative nature of the noise.     

On the absence of charge symmetry in electrostatic interaction between charged drops and hard particles

It is shown that the analytical expressions for the energy and force of electrostatic interaction between charged conducting particles (drops), a point charge, and a finite-size particle, as well as between a particle (a drop or a point charge) and a conducting plane, are asymmetric with respect to the sign of one of the charges. This is because the polarization interaction is always attractive irrespective of the signs of interacting particles. The absence of this symmetry leads to the self-constriction of charged aerodispersed systems containing a condensed phase, for example, plasma or liquid-droplet systems.     

Degenerate Hopf bifurcation in the presence of symmetry

We investigate the bifurcation of time-periodic states from a stationary state destabilized by the undamping of a set of modes associated with a degenerate pair of complex-conjugate frequencies. This problem is of particular interest for bifurcations in driven systems with symmetry whose order-parameter dimension n is even and n ≥ 4. For this case of a degenerate Hopf bifurcation a star of symmetry-equivalent limit cycles bifurcates in analogy to the star of symmetry-related domains arising at a symmetry-breaking phase transition in equilibrium systems. We illustrate this fact by analyzing a concrete example with n = 4. Within the framework of an amplitude expansion, we explicitly construct the time-periodic states and discuss their stability. In particular, it is shown that fairly general conclusions for the bifurcation behaviour can be drawn on the sole basis of the knowledge of the order-parameter symmetry.     

Gauge hierarchy in the presence of discrete symmetry

We discuss the gauge hierarchy problem in theories that posses an additional discrete symmetry. As examples, we consider two models based on the gauge groups U(1)_L×U(1)_Rand SU(2)_L×SU(2)_R×U(1), with parity transformation as the discrete symmetry. By employing a minimal choice of Higgs multiplets there is no freedom, in the semi-classical approximation, to arrange for an arbitrary hierarchy. Either one has a left-right symmetric phase (no hierarchy) or a totally asymmetric phase (infinite hierarchy). It is shown that radiative corrections, à la Coleman-Weinberg, do not smooth out the transition region separating the two phases. A finite gauge hierarchy is not realized.     

Dissipative optical solitons in the absence of bistability and modulation instability

Transversely one-dimensional localized field structures in a wide-aperture interferometer with inertialess nonlinearity of a threshold form are analyzed theoretically for the case when modulation instability of the transversely homogeneous field distributions is absent. It is shown that dissipative solitons exist even in the case of monostability (in the absence of bistability of the homogeneous distributions). In this case, the number of types of solitons turns out to be finite. The possibility of existence of pulsating solitons in an interferometer with inertialess nonlinearity is indicated.     

Adiabatic behavior of sine-Gordon solitons in the presence of perturbations

The behavior of sine-Gordon solitons in the presence of weak perturbations is considered. The procedure is based on the exact inverse scattering solution of the unperturbed sine-Gordon equation. Accounting for perturbations such as those arising from impurities, external forces as well damping and spatially inhomogeneous frequencies the corresponding perturbed operator equation can be solved by the Green's function technique if one expands the Green's operator in terms of a set of biorthogonal eigenfunctions. Ordinary linear differential equations prescribing the time evolution of the scattering data are obtained. Instead of solving the inverse scattering problem completely the adiabatic assumption is then used anticipating the result that solitons maintain their integrity to a high degree. Explicit solutions for the one-soliton dynamics are presented.Work supported by the Deutsche Forschungsgemeinschaft through the Sonderforschungsbereich Nr. 162 Plasmaphysik Bochum/Jülich