Modern Physics Letters B

A novel chemical alloying method of high-pressure and high-temperature (HPHT) has been used for the synthesis of bulk-skutterudite ${\mathrm{\text{In}}}_{0.5}{\mathrm{\text{Co}}}_4{\mathrm{\text{Sb}}}_{11.5}{\mathrm{\text{Te}}}_{0.5}$. Through HPHT method, the synthesis time has been shortened from a few days to 30min. The samples of ${\mathrm{\text{In}}}_{0.5}{\mathrm{\text{Co}}}_4{\mathrm{\text{Sb}}}_{11.5}{\mathrm{\text{Te}}}_{0.5}$ skutterudites were synthesized at 1.8–3.3GPa. We have studied the phase, the microstructure, and the temperature-dependent thermoelectric properties. The Seebeck coefficient, electrical conductivity and thermal conductivity were measured in the temperature range of 295–673K. As we expected, the thermal conductivity of sample ${\mathrm{\text{In}}}_{0.5}{\mathrm{\text{Co}}}_4{\mathrm{\text{Sb}}}_{11.5}{\mathrm{\text{Te}}}_{0.5}$ decreased with the increase of the synthetic pressure. A maximal ZT of 0.64 was achieved for the ${\mathrm{\text{In}}}_{0.5}{\mathrm{\text{Co}}}_4{\mathrm{\text{Sb}}}_{11.5}{\mathrm{\text{Te}}}_{0.5}$ synthesized at 1.8GPa at 673K. These results revealed that HPHT method may be helpful for optimizing electrical conductivity and thermal conductivity in a comparatively independent way.

Dynamics of few cycle optical pulses in non-Fermi liquid was considered. Energy spectrum of non-Fermi liquid was taken from the AdS/CFT correspondence. Conditions of quasiparticle excitation existence were defined. Non-Fermi liquid parameters impact on the shape of few cycle pulses were estimated.

In this paper, a new car-following model is proposed by considering driver’s desired velocity according to Transportation Cyber Physical Systems. The effect of driver’s desired velocity on traffic flow has been investigated through linear stability theory and nonlinear reductive perturbation method. The linear stability condition shows that driver’s desired velocity effect can enlarge the stable region of traffic flow. From nonlinear analysis, the Burgers equation and mKdV equation are derived to describe the evolution properties of traffic density waves in the stable and unstable regions respectively. Numerical simulation is carried out to verify the analytical results, which reveals that traffic congestion can be suppressed efficiently by taking driver’s desired velocity effect into account.

Under the condition of strong electron–LO–phonon coupling in a RbCl quantum pseudodot (QPD) with an applied magnetic field (MF), the eigenenergies and the eigenfunctions of the ground and the first excited states (GFES) are obtained by using a variational method of the Pekar type (VMPT). A single qubit can be realized in this two-level quantum system. The electron’s probability density oscillates in the RbCl QPD with a certain period of $T_0=7.933$ fs when the electron is in the superposition state of the GFES. The results indicate that due to the presence of the asymmetrical structure in the z direction of the RbCl QPD, the electron’s probability density shows double-peak configuration, whereas there is only peak if the confinement is a symmetric structure in the x and y directions of the RbCl QPD. The oscillating period is an increasing function of the cyclotron frequency and the polaron radius, whereas it is a decreasing one of the chemical potential of the two-dimensional electron gas and the zero point of the pseudoharmonic potential (PP).

First-principles calculations are performed to study the effect of isotropic stress on the electronic and magnetic properties of cubic bixbyite Indium oxide $({\mathrm{\text{In}}}_2{\mathrm{\text{O}}}_3)$ doped with substitution C impurities. In comparison with undoped ${\mathrm{\text{In}}}_2{\mathrm{\text{O}}}_3$ materials, the defects can induce a spin moment with 2 $\mu$B when two C atoms substitutes for two O atoms in the system. In addition, the spin moment remains the same under the condition of strain less than 2%. When the strain is more than 2%, there is a sharp transition to a high-spin magnetic moment with 4 $\mu$B and it stays in this position with the increase of strain. This high magnetoelastic effect could be utilized to design pressure-tunable spin devices based on C-doped ${\mathrm{\text{In}}}_2{\mathrm{\text{O}}}_3$.

The crystal structure, electronic structure and optical properties of N-doped ${\mathrm{\text{SiO}}}_2$ with different N impurity concentrations were calculated by density function theory within GGA+U method. The crystal distortion, impurity formation energy, band gap, band width and optical parameter of N-doped ${\mathrm{\text{SiO}}}_2$ are closely related with N impurity concentration. Based on the calculated results, there are three new impurity energy levels emerging in the band gap of N-doped ${\mathrm{\text{SiO}}}_2$, which determine the electronic structure and optical properties. The variations of optical properties induced by N doping are predominately determined by the unsaturated impurity states, which are more obvious at higher N impurity concentration. In addition, all the doping effects of N in both $\alpha$-quartz ${\mathrm{\text{SiO}}}_2$ and $\beta$-quartz ${\mathrm{\text{SiO}}}_2$ are very similar. According to these findings, one could understand the relationship between nitrogen concentration and optical parameter of ${\mathrm{\text{SiO}}}_x{\mathrm{\text{N}}}_y$ materials, and design new optoelectrionic Si–O–N compounds.

In this paper, a $(2+1)$-dimensional generalized variable-coefficient Sawada–Kotera (gvcSK) equation is investigated, which describes many nonlinear phenomena in fluid dynamics and plasma physics. Based on the properties of binary Bell polynomials, we present a Hirota’s bilinear equation to the gvcSK equation. By virtue of the Hirota’s bilinear equation, we obtain the N-soliton solutions and the quasi-periodic wave solutions of the gvcSK equation, which can be reduced to the ones of several integrable equations such as Sawada–Kotera, modified Caudrey–Dodd–Gibbon–Sawada–Kotera, isospectral BKP equations and etc. Furthermore, we obtain the relationship between the soliton solutions and periodic solutions by considering the asymptotic properties of the periodic solutions.

Electrical, optical and polarization characteristics of nanosecond discharges in the short interelectrode gap have been experimentally researched. The conditions and mechanisms of accelerated electrons formation are established. The estimates of energy, the length of accelerated electrons run and electron beam generation efficiency in the investigated discharge are obtained. The formation of electron beams is confirmed by the studies of polarization of spontaneous discharge irradiation.