http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/12048 2026-05-21T02:22:20Z 2026-05-21T02:22:20Z Hoang, Dinh Trien et al. http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/12810 2011-06-09T02:32:11Z 2010-01-01T00:00:00Z

The dependence of the nonlinear absorption coefficient of strong electromagnetic waves caused by electrons confined in rectangular quantum wires on the temperature of the system Hoang, Dinh Trien; et al. The nonlinear absorption of a strong electromagnetic wave caused by confined electrons in cylindrical quantum wires is theoretically studied by using the quantum kinetic equation for electrons. The problem is considered in the case electron-acoustic phonon scattering. Analytic expressions for the dependence of the nonlinear absorption coefficient of a strong electromagnetic wave by confined electrons in rectangular quantum wires on the temperature T are obtained. The analytic expressions are numerically calculated and discussed for GaAs/GaAsAl rectangular quantum wires.

2010-01-01T00:00:00Z Le, Trung Thanh http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/12808 2011-06-09T02:27:05Z 2010-01-01T00:00:00Z

All-optical NAND and AND gates based on 3x3 general interference multimode interference couplers Le, Trung Thanh This paper presents a new design method for all-optical NAND and AND logic gates based on 3x3 general interference multimode interference (GI MMI) coupler. The whole device is realized on the silicon on insulator (SOI) platform. The transfer matrix method (TMM) and three dimensional beam propagation method (3D-BPM) are used to optimally design these devices.

2010-01-01T00:00:00Z Duong, Ngoc Hai Nguyen, Tat Thang http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/12805 2011-06-09T02:22:25Z 2010-01-01T00:00:00Z

Development of a software package for 3D structured mesh generation Duong, Ngoc Hai; Nguyen, Tat Thang A 3D structured-mesh generation package has been developed using the transfinite interpolation (TFI) and/or the elliptic mesh generation methods to generate 3D structured meshes for the computational domain surrounding 3D regions (objects). A boundary stretching coefficient was used in the first method. And an attraction function was used in the second one. These stretching coefficient and attraction function are used to control the properties, i.e. the distribution density of the mesh points, of the meshes to be generated. The mesh generation function of the package is tested and shows its robustness. In addition, a friendly graphic user interface has also been designed and developed to assist in viewing and presenting the topographic data and the generated meshes. The package has been applied to the generation of 3D computational meshes used as the input of a computational fluid dynamics model for simulations of turbulent compressible atmospheric flows and air pollutant transport/dispersion in practical 3D domains.

2010-01-01T00:00:00Z Nguyen, Dinh Duc Nguyen, Thi Thuy http://tainguyenso.vnu.edu.vn/jspui/handle/123456789/12802 2011-06-09T02:14:03Z 2010-01-01T00:00:00Z

Composite cylinder under unsteady, axisymmetric, plane Nguyen, Dinh Duc; Nguyen, Thi Thuy With advantages such as high strength, high stiffness, high chemical resistance, light weight…composite tubes are widely applied in urban construction and petroleum industry. In this report, the authors used the displacement method to study the mechanical behavior (stress, strain…) of an infinite hollow cylinder made of composite material under unsteady, axisymmetric plane temperature field. In the numerical calculations, we mainly studied the influence of time and volume ratio of the particle on the displacement and thermoelastic stress of a cylinder made of Titanium /PVC composite.

2010-01-01T00:00:00Z