Phương Nhi 21

Nguyen, Quang Bau Dao, Thu Hang Doan, Minh Quang Nguyen, Thi Thanh Nhan We have studied magneto-thermoelectric effects in quantum well in the presence of electromagnetic wave. The analytic expression for Ettingshausen coefficient (EC) in the Quantum Well with parabolic potential (QWPP) in the presence of Electromagnetic wave (EMW) is calculated by using the quantum kinetic equation for electrons. The dependence of EC on the frequency, the amplitude of EMW, the Quantum Well parameters and the temperature are obtained. The results are numerically calculated, plotted, and discussed for GaAs/GaAsAl Quantum Well to clearly show the dependence of EC on above parameters and the results in this case are compared with the case in the bulk semiconductors. We realize that as the temperature increases, the EC decreases. The results show appearance of the Shubnikov–de Haas (SdH) oscillations when we survey the dependence of EC on the magnetic field. Chi tiết xin mời tham khảo tại ht...

Dam, Nhan Ba Luu, Tuan Tai In this report, we studied the effect of electrolyte concentration on the electrochemical and magnetic properties of the LaNi4.6Ge0.4 alloys used as the negative electrode in Ni-MH rechargeable batteries. Effect of electrolyte concentration on the electrochemical and magnetic properties of the LaNi4.6Ge0.4 alloys was investigated by the measurements of magnetization curves and charge-discharge performance of the material. The results showed that the composition electrolyte solution KOH(5.1) + LiOH(0.9), the charge-discharge performance is the highest. With this concentration of magnetization curves show superparamagnetic status and the magnetized values is the highest. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/55427   Title:  Study the Influences of Electrolyte Solution on the Electrochemical and Magnetic Properties of LaNi4.6Ge0.4 Alloys Authors:  Dam, Nhan Ba Luu, Tuan Tai Keywords:  Nano;...

Vu, Phi Tuyen Alkali borotellurite glass (ABTe) doped with concentration of 0.5 mol% Sm3+ ions was prepared by melting method. The absorption, luminescence spectra and lifetime of ABTe:Sm3+ have been measured at room temperature. The results were analyzed using Judd–Ofelt (JO) theory, that gives the Ωλ intensity parameters, transition probabilities (AR), calculated branching ratios (βR), measured branching ratios (βmes) and stimulated emission cross-sections (σλp) for 4G5/2→6HJHHJ transitions. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/55544 Title:  Judd-Ofelt Parameters of Sm3+-doped Alkali Telluroborate Glasses Authors:  Vu, Phi Tuyen Keywords:  Alkali borotellurite glass;Judd-Ofelt theory Issue Date:  2016 Publisher:  H. : ĐHQGHN Series/Report no.:  Vol. 32;No. 1 (2016) Description:  p. 61-66 URI:  http://repository.vnu.edu.vn/handle/VNU_123/55544 ISSN:  2588-1124 Appears in Collectio...

Nguyen, Van Hung Trinh, Thi Hue Nguyen, Ba Duc In this work, Morse potential parameters of bcc crystals have been calculated based on the calculation of volume per atom and atomic number in each elementary cell, as well as the energy of sublimation, the compressibility and the lattice constant. They are used for studying the anharmonic interatomic effective potential, local force constant in XAFS (X-ray Absorption Fine Structure) theory. Numerical results for Fe, W and Mo are found to be in good agreement with experiment and with those of other theories. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/55814   Title:  Calculation of Morse Potential Parameters of bcc Crystals and Application to Anharmonic Interatomic Effective Potential, Local Force Constant Authors:  Nguyen, Van Hung Trinh, Thi Hue Nguyen, Ba Duc Keywords:  Morse potential parameter;effective potential;local force constant;bcc crystals Issue Date:  20...

Dang, Thi Bich Hop Pham, Hong Quang Do, Thi Kim Anh Do, Phuc Quan Ngo, Dinh Sang The deposition of Copper-Selenium thin films was studied by using a combination of Cyclic Voltammetry (CV) and Electrochemical Quartz Crystal Microbalance (EQCM). The values of the equivalent atomic mass (M/z) grown at the gold EQCM sensor during electrodeposition at varying potentials and constant potentials were analyzed to understand the mechanism of the growing process. The composition of the films determined by EDS supports the assumption of the deposition process which is based on the EQCM studies. The obtained results indicate the role of sulfamic acid as a comlexing agent. The concentration of 20 mM of sulfamic acid and the growing potential of - 0.9 V were found to be the most suitable conditions for deposition of Copper-Selenium layers towards CIGS thin film solar cell application. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/56229   Title:...

Nguyen, Thi Thanh Ha Nguyen, Quang Bau Pham, Khac Hung In this paper, we numerically study the diffusion mechanism at atomic level in silica liquid via molecular dynamics simulation. The model consisting of 1998 particles and using the BKS potential has been constructed at the temperature from 2600 to 4500 K. Furthermore, we track the evolution of network units with x=4, 5 and 6 over different time. The simulation shows that the diffusivity depends strongly not only on the rate of the exchanging the coordinated oxygens, but also on the correlation effect. This effect is caused by the specific distribution of the exchanging coordinated oxygens (ECO) through the space which leads to spatially heterogeneous dynamics in the liquid. Analyzing the temperature dependence of the correlation coefficient F we found that the slowdown in dynamics near glass transition point is ascribed from percolation of the domains where high frequent exchanging coordinated oxygens occurs. Chi t...

Nguyen, Quy Thuong Delay fault and glitch fault cause hazards that are structure hazard and function hazard. During design process we can use many methods to identify and remove structural hazard [1-2], [3]. However, with function hazards, determination and remove much more difficult. In this paper we introduce a new solution to determine the structure hazard by the Truth table - Matrix mathematics Method and method for determining function hazard over how to determine crosstalk fault [4-71. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/56481   Title:  Detection of the location of the hazard during and after the design of combinational circuits Authors:  Nguyen, Quy Thuong Keywords:  Structure hazard;function hazard;truth table;multiplication matrix;hazard - algebra;crosstalk fault Issue Date:  2011 Publisher:  H. : ĐHQGHN Series/Report no.:  Vol. 27;No. 2 (2011) Description:  p. 123-130 URI:...