[en] We investigate the zero and finite temperature transport properties of a quasi-two dimensional electron gas in a GaAs/InGaAs/GaAs quantum well under a magnetic field, taking into account many-body effects via a local-field correction. We consider the surface roughness, roughness-induced piezoelectric, remote charged impurity and homogenous background charged impurity scattering. The effects of the quantum well width, carrier density, temperature and local-field correction on resistance ratio are investigated. We also consider the dependence of the total mobility on the multiple scattering effect. (author)

[en] We propose a version of deformed quantum field based on deformed commutation relations between creation and annihilation operators. As consequence, the model leads to the corrections for the transition amplitudes of the processes with the presence of identical particles

[en] Microtrons are accelerators of electrons and are simultaneous source of Bremsstrahlung photon flux and fission neutrons. In 1982, a microtron of seventeen trajectories Microtron MT - 17 was put into operation at the National Institute of Physics of Vietnam. Though very modest, microtrons are very useful for developing countries such as Vietnam in both fundamental and applied physics research. During the recent years by using the above mentioned MT - 17 and microtrons from other institutes we have carried out different investigation. In this report we present some results obtained in the studies of photonuclear reactions and photon activation analysis in the giant dipole resonance region. (author)

[en] The Monte-Carlo transport code, MCNP, has been applied in simulating organ dose for the MIRD-5 type adult phantom from isotropic semi-infinite photon sources in the air with source energies from 10 keV to 5 MeV. The minimum radius of source representing the semi-infinite source size is also determined. The obtained results of the organ dose were also compared with K. F. Eckerman et al. It is found that the present data are lower than those of K. F. Eckerman et al. However, the present data are lower than those of K. F. Eckerman et al in all energy regions. A possible reason is the difference in calculated by the Monte Carlo method, while those of K. F. Eckerman et al were calculated by the deterministic method. (author)

[en] We discuss the decay of squarks (s top and s bottom) into quarks (top and bottom) and gluinos in the Minimal Supersymmetric Standard Model (MSSM) with complex parameters At, Ab. the analytical and numerical results for the decay widths are given. We show that the effect of these CP phases on the decay widths of s top and s bottom decay can be quite significant in a large region of the MSSM parameter space. SUSY-QCD corrections to the decay widths have been included. (author)

[en] In this article the gradient force of optical trap using two counter- propagating pulsed Gaussian beam and the Brownian motion in optical force field are investigated. The influence of the energy and duration time of optical pulsed Gaussian beams on stability of nano-particle in trap is simulated and discussed. (author)

[en] SnO₂ nanorods have been successfully prepared by hydrothermal method using tin chloride, ammonia, sodium hydroxide and cetyltrimethyl ammonium bromide (CTAB) as starting materials. Structural properties and surface morphologies of the SnO₂ nanorods were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). the experimental results show that diameters of the nanorods are around 100 nm to 300 nm with length of several micrometers. in the preparation process of nanorods, the surfactant CTAB plays an important role in the formation and growth processes of SnO₂ nanorods. The gas sensitivity experiments have demonstrated that the SnO₂ nanorods exhibit a good sensitivity to alcohol vapors, which may offer potential applications in the gas sensors. (author)

[en] We present a theory of the band-bending effects on two-dimensional (2D) carriers confined in symmetrically-modulated square quantum wells. We develop a tractable variational evaluation several physical quantities that are important in the theory of 2D systems. Analytic expressions of the envelop wave function and the 2D screening form factor allow us to compute various electronic properties such as electrical mobility, density of states in the presence or in the absence magnetic fields, and Landau level broadening. (author)

[en] Organometal halide perovskite materials have shown high potential as light absorbers for photovoltaic applications. In this work, perovskite planar solar cells were fabricated on corning substrates with the structure as follows: the first layer made of tantalum-doped tin oxide as transparent contact material, followed by sputtering niobium-doped titanium oxide as the compact electron transport layer; covered with perovskite CH₃NH₃PbI₃ as the light harvester by combination between spin-coating and dipping methods; CuSCN was evaporated as the hole transport layer; the final thin Al/Ag electrodes were deposited. This configuration is shortly described as Al/TTO/NTO/CH₃NH₃PbI₃/CuSCN/Ag. Such heterojunctions are expected to be suitable for the development of efficient hybrid solar cells. The fabricated cells were measured under the air mass 1.5 illumination condition, showed the rectification effect and exhibited a power conversion efficiency of 0.007%, with a open circuit voltage of 53.2 mV, a short circuit current of 0.36 mA/cm², and a form factor of 37%. The power conversion efficiency will be further optimized in near future. (author)

[en] We study the production of Higgs and Z bosons which has been proposed as an option of e"+e"- collision at the ILC, CLIC with the polarization of the electron and positron beams in Randall-Sundrum model (RSM). The differential cross-sections are presented and numerical evaluation is given. Based on the results, we show that the advantageous direction to collect Higgs is perpendicular to the direction of the initial e"- beam. With the high integrated luminosity and at the high degree of polarization, the reaction can give observable cross-sections in future accelerators (ILC, CLIC). (author)