Phương Nhi

Nguyen, Thi Hue Vu, Thi Thanh Tam Nguyen, Anh Tuan In this report, we use a sum-frequency generation vibrational spectroscopy to measure SFG spectra from 1-Butanol monolayers on pure water and halide saline solution interfaces. These spectra indicate that halide anions have different effects on the structure of 1-Butanol monolayer/water interfaces. The obtained SFG spectra suggest that the I¯ anions mostly disturb the interfacial structure due to their largest surface propensity among those investigated. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/55391   Title:  Effect of halide anions on structure of 1-butanol monolayer/water interface probed by sum-frequency vibrational spectroscopy Authors:  Nguyen, Thi Hue Vu, Thi Thanh Tam Nguyen, Anh Tuan Keywords:  Interfacial structure;Sum-frequency vibrational spectroscopy;1-Butanol;halide salt Issue Date:  2017 Publisher:  H. : ĐHQGHN Series/Report no.:  Vol. 3...

Vu, Ngoc Tuoc Nguyen, Thi Thao The advancement of technology has now made to enable not only growth materials in layer-by-layer or even in sub-layer with a desired ingredient. Further, it is expected to enable to manipulate on material layers at the desired address. This opens up opportunities for creating porous structures with specific allotropes - the purpose of materials engineering geometry. Zinc oxide (ZnO) material, along with wurtzite and zinblende, has been found in a large number of allotropes with substantially different properties, and hence, applications. Therefore, predicting and synthesizing new classes of ZnO allotropes is of great significance and has been gaining considerable interest. Herein, we perform a density functional theory based study, predicting several new series of ZnO hollow structures using the engineering geometry approach. The geometry of the building blocks allows for obtaining a variety of triangular, low-density nanoporous, and flexib...

Nguyen, Van Yen Nguyen, Van Hong Le, The Vinh The structural characteristics of liquid PbSiO3 have been investigated by means of the molecular dynamics simulation. The simulations were done in a microcanonical ensemble, using pair potentials. Models consisting of 5000 atoms (1000 Pb, 1000 Si and 3000 O) were constructed at different pressures and at temperatures 3200 K. The local structure and network topology were analyzed through radial distribution function, bond angle distributions and coordination number distribution. The local environment around Pb atoms and continuity of silica and lead oxide sub-networks as well as their change under compression are also discussed in detail, moreover, we have used visualization techniques illustrated network structure. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/55813   Title:  The Structure of Liquid PbSiO3: Insight from Analysis and Visualization of Molecular Dynamics Data Authors:...

Tran, Ngoc Spectroscopic properties of Dy3+ and Ce3+ ions doped alkali metal borate glasses (70-x-y)B2O3.15Li2CO­­3.15Na2CO3.xDy2O3 and yCeO2 (BLN:Dy,Ce) fabricated by melting method have been studied. Energy transfer from the absorption and fluorescence center has been discussed. Judd–Ofelt (J-O) theory has been used to evaluate various spectroscopic properties such as oscillator strengths (fexp, fcal), intensity parameters Ωl(l=2,4,6), spontaneous transition probabilities (AR), radiative life times (tR) and luminescence branching ratios (σexp, σR). The cross-relaxation mechanism was discussed for BLN glass. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/55972   Title:  Optical Properties of Dy3+ and Ce3+ in Borate Glass Authors:  Tran, Ngoc Keywords:  Alkali metal borate glass;Energy transfer;cross-relaxation mechanism Issue Date:  2015 Publisher:  H. : ĐHQGHN Series/Report no.:  Vol. 31;No. 1 (2015) ...

Nguyen, The Binh Nguyen, Dinh Thanh Nguyen, Quang Dong Nguyen, Thi Trinh Using Nd:YAG laser we studied to produce platinum nanoparticles (PtNPs) in solution of polyvinyl pyrrolidone (C6H9NO)n (PVP) by laser ablation method. The influence of average laser power, laser irradiation time, laser wave length and concentration of PVP solution in water on morphology, size distribution of PtNPs was investigated. The mean diameter of the PtNPs in 0.01M PVP solution was of 9 nm. The results on an optimum laser ablation process for preparation of PtNPs in PVP solution were discussed in this paper. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/56061   Title:  Preparation of Platinum Nanoparticles in Solution of Polyvinyl Pyrrolydone (PVP) by Laser Ablation Method Authors:  Nguyen, The Binh Nguyen, Dinh Thanh Nguyen, Quang Dong Nguyen, Thi Trinh Keywords:  Laser ablation;plasmon resonance;nanoparticle;second harmonic Issue Date: ...

Vu, Thi Thuy Anh Nguyen, Dinh Duc To increase the thermal resistance of various structural components in high-temperature environments, research reports focusing nonlinear axisymmetric response of thin FGM shallow spherical shells with ceramic – metal – ceramic layers (S-FGM) under uniform external pressure and temperature. Equilibrium and compatibility equations for shallow spherical shells are derived by using the classical shell theory and specialized for axisymmetric deformation with both geometrical nonlinearity and initial geometrical imperfection. One-term deflection mode is assumed and explicit expressions of buckling loads and load–deflection curves are determined due to Galerkin method. Stability analysis for a clamped spherical shell shows the effects of material and geometric parameters, edge restraint and temperature conditions, and imperfection on the behavior of the shells. The results were compared with the P-FGM spherical shell symmetry axis (ceramic – m...

Nguyen, Quy Thuong Composite material with polymer matrix - titanium particle is qidely applied in Vietnam, today. In this paper, the bending of thin polymer composite plate with Titanium particles under the effect of the steady temperature field is investigated. The paper has established the boundary problem of a simply supported composite plate reinforced by particles under the influence of steady heat transfer process. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/56346   Title:  Detection o f the location o f the hazard during and after the design o f combinational circuits Authors:  Nguyen, Quy Thuong Keywords:  Composite plate;bending;steady heat transfer;polymer PVC Issue Date:  2012 Publisher:  H. : ĐHQGHN Series/Report no.:  Vol. 28;No. 2 (2012) Description:  p. 77-83 URI:  http://repository.vnu.edu.vn/handle/VNU_123/56346 ISSN:  2588-1124 Appears in Collections: Mathematics a...

Nguyen, Van Mau We deal with a class of function equation in plane geometry. The main our purpose is to describe the general solutions of the following functional equation iin plane geometry. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/56444   Title:  On the solution of a class of function equation in plane geometry Authors:  Nguyen, Van Mau Keywords:  Mathematics;plane geometry Issue Date:  2011 Publisher:  H. : ĐHQGHN Series/Report no.:  Vol. 27;No. 2 (2011) Description:  p. 85-89 URI:  http://repository.vnu.edu.vn/handle/VNU_123/56444 ISSN:  2588-1124 Appears in Collections: Mathematics and Physics

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 (shess, 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. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/56681   Title:  Composite cylinder under unsteady, axisymmetric, plane temperature field Authors:  Nguyen, Dinh Duc Nguyen, Thi Thuy Keywords:  Composite cylinder;temperature field Issue Date:  2010 Publisher:  H. : ĐHQGHN Series/Report no.:  Vol. 26;N...

Nguyen, Van Hung Ngo, Trong Hai Tong, Sy Tien Le, Hai Hung Anharmonic effective potential, effective local force constant, thermal expansion coefficient, three leading cumulants, and EXAFS (Extended X-ray Absorption Fine Structure) of hep crystals have been studied. Analytical expressions for these quantities have been derived. Numerical calculations have been carried out for Zn and Cd. They show a good agreement with experiment results measured at HASYLAB (DESY, Germany) and unnegligible anharmonic effects in the considered quantities. Chi tiết xin mời tham khảo tại http://repository.vnu.edu.vn/handle/VNU_123/56734   Title:  Anharmonic effective potential, thermodynamic parameters, and EXAFS of hep crystals Authors:  Nguyen, Van Hung Ngo, Trong Hai Tong, Sy Tien Le, Hai Hung Keywords:  Anharmonic effective potential;thermodynamic parameters;EXAFS of hep crystals Issue Date:  2009 Publisher:  H. : ĐHQGHN Series/Report no.:  Vol. 25;No....