Modern Physics Letters B

Heat transfer in double-layer systems with superfluid helium as one of the layers is studied in this paper. Double-layer systems like heater-helium and helium-detector were considered. The limiting cases of the relation of the non-helium layer length and the length of the heat wave in it were investigated. The unusual resonances were found in the double-layer system helium-detector. Analytical expressions for width and amplitudes of these resonances were obtained. At the same time it was found that the resonance width in helium can be determined not by the dissipative properties of helium, but by the thermodynamic parameters of the detector.

The aim of this study is to investigate the effects of gold nanoparticles on breast cancer tumor. A theoretical approach has been adopted to probe the nanophotolysis technique using short pulse laser. The influences of various parameters including number of ions, shock front, energy distribution function, laser fluence are discussed in detail. Computational results suggest that spherical gold nanoparticles provides a promising platform for selective killing of abnormal cells in breast cancer tumor.

10-nm-thick amorphous LaAlO₃ film was deposited on n-type Si (001) substrate at 600°C by magnetron sputtering and then annealed in N₂ ambience at 300°C for 2 min using a rapid thermal annealing furnace. Grazing incidence X-ray diffraction analyses indicated that the post-annealed LaAlO₃ film was still amorphous. The root-mean-square roughness of the post-annealed sample is a little smaller than that of the as-grown sample, which could stem from the densification of LaAlO₃ film after post-annealing. No obvious hysteretic behavior was observed in the capacitance–voltage measurement and the dielectric constant of LaAlO₃ film was estimated to be 16.7. Due to the deficiency of oxygen vacancy after post-annealing, the low leakage current density of the post-annealed film with EOT of 2.33 nm is about 5.52 × 10^-5 A/cm² at +1 MV/cm. Moreover, it is found that both the as-grown and post-annealed capacitors satisfy Ohmic conduction behavior at the whole positive measured electric fields.

The dynamical behavior of tumor growth model driven by Lévy noise terms is investigated. For α = 2 and β = 0, the process driven by white Lévy noise approach to the standard Gaussian white noise can be viewed in the analysis of the steady-state probability distribution and the mean first-passage time. When β → 0, the index α would increase the mean first-passage time as scale σ < 0 and shorten the mean first-passage time as scale σ > 0. A nonzero β parameter induces α to decrease the mean first-passage time. Thus analyzing the initial situation of tumor is very important to obtain more therapy time.

A mode separation approach in the nanoring resonator by a cascaded slot cavity is proposed and numerically investigated using the finite-difference time-domain (FDTD) method. With the cascaded slot cavity, the specified modes in the nanoring can be separated to realize a wide free spectral range (FSR) or single channel filtering, which provides a free degree to the plasmonic filters design. Simulation results also demonstrate that the full-width at half-maximum (FWHM) of the single channel filter obtained from the cascaded slot cavity can be effectively reduced to meet various requirements.

In this paper, we model the tick-by-tick dynamics of markets by using the continuous-time random walk (CTRW) model. We employ a sum of products of power law and stretched exponential functions for the waiting time probability distribution function; this function can fit well the waiting time distribution for BUND futures traded at LIFFE in 1997.

Nonlinear Schrödinger equations and corresponding quantum hydrodynamic (QHD) equations are widely used in studying of ultracold boson–fermion mixtures and superconductors. In this article, we show that more exact account of interaction in Bose–Einstein condensate (BEC), in comparison with the Gross–Pitaevskii (GP) approximation, leads to the existence of a new type of solitons. We use a set of QHD equations in the third order by the interaction radius (TOIR), which corresponds to the GP equation in the first order by the interaction radius. We analytically obtain a soliton solution which is an area of increased atom concentration. The conditions for existence of the soliton are studied. It is shown what solution exists if the interaction between the particles is repulsive. Particle concentration has been achieved experimentally for the BEC is of order of 10¹²–10¹⁴ cm^-3. In this case the solution exists if the scattering length is of the order of 1 μm, which can be reached using the Feshbach resonance. It is one of the limit case of existence of the solution. The corresponding scattering length decrease with the increasing of concentration of particles. We have shown that account of interaction up to TOIR approximation leads to new effects. The investigation of effects in the TOIR approximation gives a more detail information on interaction potentials between the atoms and can be used for a more detail investigation of the interatomic potential structure.

The author has developed a discrete model for simulation to calculate the threshold voltage (V_T) shift caused by charge trapping and detrapping in a thin film transistor (TFT) under a time-varying bias. The model divides continuous states into discrete states and simplifies tunneling among the discrete states to keep track of their occupancies. The simulation is carried out for a TFT that has traps in the gate dielectric uniformly distributed perpendicular to the semiconductor/dielectric interface and the results account for the stretched-exponential time dependence of V_T shift.