Lump,lumpoff and predictable rogue wave solutions to the (2+1)-dimensional asymmetrical Nizhnik-Novikov-Veselov equation

This paper mainly uses Hirota bilinear form to investigate the (2+1)-dimensional asymmetrical Nizhnik-Novikov-Veselov equation. We obtain the general lump solutions and discuss its positiveness, the propagation path, amplitude and position at any time. Based on the general lump solutions, lumpoff solutions which a combination of lump solitons and stripe solitons, are also triumphantly acquired. Similarly, according to the general lump solutions, we are also consider a particular rogue wave by introducing a pair of stripe solitons, and research its predictability which include the time of the rogue wave appearance, position at time, propagation path and the maximum value of wave height. Finally, some figures are given to explain the movement mechanism of these solutions.     

Non-trivial effect of the in-plane shear elasticity on the phase transitions of fixed-connectivity meshwork models

We numerically study the phase structure of two types of triangulated spherical surface models, which includes an in-plane shear energy in the Hamiltonian, and we found that the phase structure of the models is considerably influenced by the presence of the in-plane shear elasticity. The models undergo a first-order collapsing transition and a first-order (or second-order) transition of surface fluctuations; the latter transition was reported to be of second-order in the first model without the in-plane shear energy. This leads us to conclude that the in-plane elasticity strengthens the transition of surface fluctuations. We also found that the in-plane elasticity decreases the variety of phases in the second model without the in-plane energy. The Hamiltonian of the first model is given by a linear combination of the Gaussian bond potential, a one-dimensional bending energy, and the in-plane shear energy. The second model is obtained from the first model by replacing the Gaussian bond potential with the Nambu-Goto potential, which is defined by the summation over the area of triangles.     

Photon-assisted shot noise due to the charging effect in a quantum dot device

We have investigated the spectral density of shot noise for an ultra-small quantum dot(QD) system in the Coulomb blockade regime when irradiated with microwave fields (MWFs) by employing a nonequilibrium Green’s function technique. The shot noise is sensitive to Coulomb interaction, and the photon-assisted Coulomb blockade behaviour strongly modifies the mesoscopic transport. We have calculated the first and second derivatives of shot noise in the strong and weak coupling regimes to compare the theoretical results with existing experimental results. In the strong coupling regime, the first and second derivatives of shot noise display Fano type peak-valley structures around the charging channel 2E _c due to Coulomb interaction. When the magnitudes of the MWFs are sufficiently large, the system displays channel blockade due to photon irradiation. The photon-assisted and Coulomb blockade steps in the noise — as well as the resonant behaviour in the differential noise — are smeared by increasing temperature. The Coulomb interaction suppresses the shot noise, but the ac fields can either suppress the shot noise(balanced case) or enhance the shot noise(unbalanced case). The suppression of shot noise caused by ac fields in the balanced case is greater than that caused by Coulomb interaction in our system. Super-Poissonian shot noise may be induced due to the compound effects of strong Coulomb interaction and photon absorption-emission processes.     

Optimized Monte Carlo analysis for generalized ensembles

We present a new, maximum-likelihood based method to combine data from a multiple number of Monte Carlo simulations performed within any type of ensemble. The method offers an efficient iterative scheme to obtain the density of states of a wide range of energies as well as of other macroscopic variables. It should in particular be useful for the study of systems with a rough energy landscape. Received 4 June 2002 Published online 14 October 2002 RID="a" ID="a"e-mail: borg@alf.nbi.dk     

Rest Energy of Classical Self Fields of Point Gravitating Sources

A variant of Brans-Dicke theory is discussed in which the singularities of electric, scalar and metric sector of classical self fields of a point gravitating source are in Jordan frame suppressed and their energy - momentum tensor is integrable. The total energy of the classical electron Coulomb field is finite and in accordance with special relativistic expression m ₀ c ². The same may be said with respect to total rest energy of the quasi-Coulomb field, i.e. the scalar self-field of the source in the case of electron and in the case of a source with zero electric charge. Although (pseudo-)Einstein equations in (pseudo-)Pauli frame are modified, all experimental predictions concerning gravitational effects of macroscopic (celestial) bodies are in accordance with that of GRT.     

Noncommutative Unification of General Relativity and Quantum Mechanics. A Finite Model

We construct a model unifying general relativity and quantum mechanics in a broader structure of noncommutative geometry. The geometry in question is that of a transformation groupoid given by the action of a finite group on a space E. We define the algebra of smooth complex valued functions on , with convolution as multiplication, in terms of which the groupoid geometry is developed. Owing to the fact that the group G is finite the model can be computed in full details. We show that by suitable averaging of noncommutative geometric quantities one recovers the standard space-time geometry. The quantum sector of the model is explored in terms of the regular representation of the algebra , and its correspondence with the standard quantum mechanics is established.     

Dynamical behavior of electron transport in AlGaAs/GaAs double-barrier structures under a high-frequency radiation field

We investigate the time-dependent dynamical behavior of electron transport in AlGaAs/GaAs double-barrier structures under a high-frequency radiation field. The effects of the radiation field with different amplitude and frequency on the real-time and mean current-voltage curves are taken into account. We find that the amplitude and frequency of the radiation field affect the final stable state current-voltage (I-V) behaviors, which leads to the switching between different current states at a smaller bias than that of the absence of the radiation field, and both current hysteresis and resonant peaks are suppressed by the external radiation field. The high radiation field strength can make the resonant peak of current split and the hysteresis of current disappear. This effect provides the potential to use double-barrier structure as a THz photoelectric switch.     

智能光网络的应用探讨

随着传输技术的不断进步和数据及互联网业务的迅猛发展,智能光网络的应用越来越广泛。智能光网络具有路由自动恢复、动态支持业务、网络可靠灵活等技术特点。智能光网络的网络结构采用网状组网方式,其控制平面采用分布式处理方式并与网络管理系统共同完成网络的控制与管理,智能光网络可以从现有骨干网络和城域核心网络进行引入。     

基于B/S结构的高性能SAR图像处理系统

文章提出了一种基于浏览器/服务器（B/S）结构的SAR图像处理系统的解决方案,通过将用户交互界面与图像计算功能的分离,充分利用了服务器的强大计算能力和浏览器灵活的访问方式,自然的实现了SAR图像处理及情报上传功能,在我们实际的应用中取得了较好的效果.