Thứ Hai, 28 tháng 8, 2017

Tái lập Hội Thư viện: Kinh nghiệm ở In-đô-nê-xia

Authors: Gani, Fuad
Zen, Zulfikar
Keywords: Thông tin thư viện;Hiệp hội thư viện;Inđônêxia
Issue Date: 2009
Publisher: Đại học Quốc gia Hà Nội
Description: tr. 467-475
Kỷ yếu đại hội cán bộ thư viện các nước Đông Nam Á lần thứ 14
URI: http://repository.vnu.edu.vn/handle/VNU_123/31286
Appears in Collections:Kỷ yếu Hội nghị - Hội thảo (LIC)

Các lý thuyết kinh tế trong bối cảnh khủng hoảng kinh tế toàn cầu và thực tiễn Việt Nam

Keywords: Kinh tế học;Lý thuyết kinh tế
Issue Date: 2010
Publisher: H. : ĐHQGHN
Description: 442 tr.
URI: http://repository.vnu.edu.vn/handle/VNU_123/34214
Appears in Collections:Kỷ yếu Hội nghị - Hội thảo (LIC)

Thứ Sáu, 25 tháng 8, 2017

Study of self-diffusion in semiconductors by statistical moment method

Authors: Vu, Van Hung
Nguyen, Quang Hoc
Phan, Thi Thanh Hong
Keywords: self-diffusion;statistical moment method
Issue Date: 2004
Publisher: H. : ĐHQGHN
Series/Report no.: Vol. 20;No. 1 (2004)
Abstract: Using the statistical moment method, self-diffusion in semiconductors is studied including the anharmonic effects of lattice vibrations. The interaction energies between atoms in semiconductors are estimated by applying many-body potential. The activation energy Q and pre-exponential factor D{) of the self-diffusion coefficient are given in closed forms. The values of Q and D0 are calculated for Si and GaAs at high temperature region near the melting temperatures and they shown to be in good agreement with the experimental data.
Description: p. 23-30
URI: http://repository.vnu.edu.vn/handle/VNU_123/57889
ISSN: 2588-1124
Appears in Collections:Mathematics and Physics

Thứ Ba, 22 tháng 8, 2017

Thermodynamic and correlation effects in atomic vibration of bcc crystals containing dopant atom

Authors: Nguyen, Van Hung
Ho, Khac Hieu
Nguyen, Cong Toan
Keywords: Thermodynamic effects;correlation effects;atomic vibration;dopant atom
Issue Date: 2006
Publisher: H. : ĐHQGHN
Series/Report no.: Vol. 22;No. 1 (2006)
Abstract: A new procedure for calculation and analysis of thermodynamic and correlation effects of bcc crystals under in fluence of dopant atom in the X-ray Absorption Fine Structure (XAFS) has been developed. Analytical expression for the Displacement-displacement Correlation Function (DCF) CR has been derived based on the derived Mean Square Relative Displacement (MSRD) 2 Ơ2 and Mean Square Displacement (MSD) u of bcc crystals containing dopant atom. Numerical calculations have been carried out for Fe doped by w and by Cr atom. They are found to be in good agreement with experiment.
Description: p. 26-32
URI: http://repository.vnu.edu.vn/handle/VNU_123/57779
ISSN: 2588-1124
Appears in Collections:Mathematics and Physics

Image and video compression for wireless networks

Authors: Ho, Anh Tuy
Nguyen, Vinh An
Keywords: video compression;Image compression;wireless networks
Issue Date: 2006
Publisher: H. : ĐHQGHN
Series/Report no.: Vol. 22;No. 1 (2006)
Abstract: The demands for transmission of image, video and multimedia over wireless networks are increasing very rapidly. The inherently characteristics of wireless medium as bandwidth narrowing, interferences and fading are big challenges. The traditional compression techniques can not adapt to this changes. In this paper, we will discuss of issues of using wavelet compression for image and video over wireless networks. This paper also introduces some change of wavelet parameters in order to improve quality of transmission image and video over wireless network conditions.
Description: p. 33-46
URI: http://repository.vnu.edu.vn/handle/VNU_123/57780
ISSN: 2588-1124
Appears in Collections:Mathematics and Physics

Thứ Năm, 10 tháng 8, 2017

Electronic Structure of a Molecular Magnet from Salicylate Based Copper Complex

Authors: Nguyen, Duc Tho
Nguyen, Thuy Trang
Hoang, Nam Nhat
Keywords: Molecular magnet;DFT;Electronic structure
Issue Date: 2012
Publisher: H. : ĐHQGHN
Series/Report no.: Vol. 28;No. 1 (2012)
Abstract: The electronic structure of the metallo-organic compound Cu(SA)2(2-PM)2 (2-PM is 2-pyridylmethanol) is presented. The calculation was performed using the Density Functional Theory with unrestricted spin polarized model and large wave function basis sets which include the polarized and diffuse functions. The single point energy calculation for the isolated molecule gave the HOMO-LUMO separation of 3.8 eV and the LDA+U band structure calculation showed the band gap of only 0.38 eV. The calculated magnetic moment per molecule is comparable to the experimentally observed value.
Description: p. 26-31
URI: http://repository.vnu.edu.vn/handle/VNU_123/56354
ISSN: 2588-1124
Appears in Collections:Mathematics and Physics

Dynamics and mechanism diffusion in silica liquid: Insight from simulation

Authors: Nguyen, Thi Thanh Ha
Nguyen, Quang Bau
Pham, Khac Hung
Keywords: silica liquid;Dynamics;mechanism
Issue Date: 2012
Publisher: H. : ĐHQGHN
Series/Report no.: Vol. 28;No. 1 (2012)
Abstract: 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.
Description: p. 32-38
URI: http://repository.vnu.edu.vn/handle/VNU_123/56358
ISSN: 2588-1124
Appears in Collections:Mathematics and Physics