Self-Trapping in Discrete Nonlinear Schrodinger Equation with Next-Nearest Neighbor Interaction

The dynamical self-trapping of an excitation propagating on one-dimensional of different sizes with nextnearest neighbor (NNN) interaction is studied by means of an explicit fourth order symplectic integrator. Using localized initial conditions, the time-averaged occupation probability of the initial site is investigated which is a function of the degree of nonlinearity and the linear coupling strengths. The self-trapping transition occurs at larger values of the nonlinearity parameter as the NNN coupling strength of the lattice increases for fixed size. Furthermore, given NNN coupling strength, the self-trapping properties for different sizes are considered which are some different from the case with general nearest neighbor (NN) interaction.

What can the changes in shield resistance tell us during the period of shearer's cutting and neighboring shields' advance?

In order to determine the influence of shearer's cutting and neighboring shields' advance on the support resistance variation, leg pressure data of all 235 shields in the panel LW61 of Cumberland coal mine were analyzed. The results show that the relationship between the leg pressure increment and the distance from shield to front drum of shearer is a quadratic function and that the higher leg pressure increment before shield advance tends to be related to adverse roof conditions. In addition, the three proposed leg pressure increment-related parameters and the three traditional parameters(time-weighted average pressure, setting pressure, and final pressure) of approximately 32000 shield supporting cycles were calculated by a self-developed software package to analyze the correlation between them. The results show that there is a powerful connection between them, and that the three proposed leg pressure increment-related parameters could be used as the indexes to evaluate the interaction between shields and the roof, and to identify the periodic weighting.

COMPUTER SIMULATION OF A SINGLE POLYMER CHAIN IN DIFFERENT SOLVENTS

In the present paper, the behavior of a single polymer chain under various solvent conditions was modeled by self-avoiding walks (SAW) with nearest neighbors attraction Ae on a simple cubic lattice. Determination of the 0-condition was based on the numerical results of the mean square radius of gyration and end-to-end distance. It was found that at the 0 temperature Delta epsilon /kT equals -0.27. The exponents a in the Mark-Houwink equation with different interaction parameters are consistent with the results of experiments: under 0-condition, alpha= 0.5, and for a good solvent alpha =0.74-0.84, respectively.

Computational Model of Edge Effects in Graphene Nanoribbon Transistors

We present a semi-analytical model incorporating the effects of edge bond relaxation,the third nearest neighbor interactions,and edge scattering in graphene nanoribbon fi eld-effect transistors(GNRFETs)with armchair-edge GNR(AGNR)channels.Unlike carbon nanotubes(CNTs)which do not have edges,the existence of edges in the AGNRs has a signifi cant effect on the quantum capacitance and ballistic I V characteristics of GNRFETs.For an AGNR with an index of m=3p,the band gap decreases and the ON current increases whereas for an AGNR with an index of m=3p+1,the quantum capacitance increases and the ON current decreases.The effect of edge scattering,which reduces the ON current,is also included in the model.