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95. Photoelectron Spectra Induced by Broad-Band Chaotic Light
from a Structured Sontinuum
Van Cao Long, Wieslaw Leoski, and Khoa Doan Quoc
Quantum Optics and Engineering Division, Institute of Physics,
Zielona Góra University, ul. Prof. A. Szafrana 4a, 65-516 Zielona
Góra, Poland
The different ionization processes of atoms in laser fields are center
of interest in both theoretical and experimental researches in atomic
physics since long time. One of the most interesting example of
these processes is so-called laser induced autoionisation in which a
nontrivial structure of continuum occurs due to mixing of the
ionising states with continuum. In this paper we consider a model
for laser-induced autoionisation introduced before in [1]. Following
[2] we assume that the laser light is decomposed into two parts: the
deterministic or coherent part and the one, being randomly
fluctuating chaotic component, which is a -correlated, Gaussian,
Markov and stationary process (white noise). This model for the
field is interesting by itself, because it describes electric field
amplitude of the multimode laser, operating without any correlation
between the modes. We solve a set of coupled stochastic integrodifferential
equations, describing a double Fano model for
autoionisation. We determine the exact photoelectron spectrum and
compare it with our results obtained before in [1] and [2].
Our paper is organised as follows: After an introduction, in the
second section we present some details of our model and derive the
equation for atomic operators. In the third part our results are
presented and discussed. Instead of presenting rather complicated
formula (some details of the calculations leading to that formula can
be found in the appendix) we have restricted ourselves to the two
interesting physical limits: weak and strong fluctuations.
References
[1] W. Leoński, R. Tanaś and S. Kielich 1987 J. Opt. Soc. Am. B4
72.
[2] V. Cao Long, M. Trippenbach 1986 Z. Phys. B 63 267.
Báo cáo Treo
V. Vật lý tính toán, mô phỏng và mô hình hóa.
96. Inferring Amino Acid Interactions in Proteins using Maximum
Entropy Approach
Trinh Xuan Hoang
Institute of Physics, VAST, 10 Dao Tan, Ba Dinh, Ha Noi
The principle of maximum entropy is a powerful approach for
statistical inference which is maximally non-committal to missing
information. We review current methods for deducing knowledgebased
potentials in proteins and present a novel technique, based on
the principle of maximum entropy, for deriving the solvation energy
parameters of amino acids from the knowledge of the solvent
accessible areas in experimentally determined native state
structures.
Báo cáo Mời
97. Some Theoretical Issues of Wireless High Power Transmissions
and a Mathematical Model of the Wireless Solar Power
Transmission Problem from an Orbit in the Space to the Earth’s
Surface.
Dao Khac An
Institute of Materials Science, VAST, 18 Hoang Quoc Viet, Cau Giay,
Hanoi Viet nam
The application of radio for telecommunications that has
tremendous results throughout the 20th century, where the signals
containing structural information with the nano-micro watt ranging
power are wirelessly transmitted between stations. In 1900 Nicola
Tesla, an inventor and scientist proposed the use of radio waves to
transmit power instead of using high voltage power lines. Since then
the theoretical and practical results of WPT have not been improved
so much. Recently due to a lack of energy supply for the mankind,
one has intensively concentrated to develop and solve the issues of
wireless power transmission (WPT) for energy charging to the
electrical equipments, and also to find sustainable new sources of
clean energy. This presentation outlines briefly some issues and
challenges of WPT such as some theoretical and methodological
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issues of WPT by near field, by far field, then the presentation will
focus on some our research results of building mathematical model
of wireless solar power transmission problem from an space orbit to
the Earth’s surface using high power microwave beam. The
mathematical formulas of Maxwell equation system and formula of
high energy flux for WPT with abnormal features of transmission
environment and some main influences factors of space and earth’s
atmosphere on the WPT are presented. The challenges and
orientation developments are also offered and discussed.
(computional physics)
Báo cáo Miệng
98. Atomic Mechanism of Homogeneous Melting of bcc Fe at Limit of
Superheating
Tran Phuoc Duy and Vo Van Hoang
Department of Applied Physics, Faculty of Applied Science, Institute
of Technology of HochiMinh City , 268 Ly Thuong Kiet Street,
District 10, HochiMinh City-Vietnam
Atomic mechanism of homogeneous melting of the bulk bodycentered
cubic (bcc) Fe has been studied via monitoring spatiotempmiệng
arrangement of liquid-like atoms during heating
process. Calculations were performed by molecular dynamics
simulation. Liquid-like atoms were detected by the Lindemann
critrerion of melting. We found that liquid-like atoms occur
randomly in crystalline matrix at temperature far below the melting
point due to local instability of the crystal lattice. Number of liquidlike
atoms increases with increasing temperature and they have a
tendency to form clusters and melting occurs when percolated
liquid-like cluster is formed in the crystalline model. Occurrence of
melting is also accompanied by the sudden changes in various static
and thermodynamic quantities. However, total melting can be
reached at the point far above the melting one. We found three
characteristic temperatures of the homogeneous melting of bcc Fe.
Báo cáo Miệng
99. Computer Simulation of Microscopic Bubbles in Amorphous
alloy Co 81.5 B 18.5
Hội nghị Vật lý lý thuyết toàn quốc lần thứ 35
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Pham Huu Kien, Pham Khac Hung, and Vu Van Hung
Department of Computational Physics, Hanoi University of
Technology. Department of Physics, Hanoi University of Education
Simulation of the diffusion mechanism via microscopic bubbles in
amorphous materials is carried out using the statistical relaxation
models Co 81.5 B 18.5 containing 2×10 5 atoms. The present work is
focused on the role of these bubbles for self-diffusion in amorphous
solids. It was found that the numbers of the vacancy bubbles (VB)
in amorphous Co 81.5 B 18.5 vary from 1.4×10 -3 to 4×10 -3 per atom
depending on the relaxation degree. The simulation shows the
collective character of the atomic movement upon diffusion atoms
moving. Due to the large size in comparison with B atom, the jump
of a Co diffuses atom leads to a significant local rearrangement of
the atoms located near the VB. Meanwhile, B diffuses like the
movement of an interstitial impurity through the boron-VB.
Diffusion coefficients have been calculated via the vacancy bubbles
and they are consistent with experimental data. The effect of the
relaxation is also investigated and interpreted as a result of vacancybubble
annihilation during thermal annealing.
Keywords: Bubbles; Amorphous alloys; Vacancy bubbles;
Diffusion mechanism; Statistical relaxation.
Báo cáo Miệng
100. Computational Design of Mn 4 Molecules with Strong
Intramolecular Exchange Coupling
Nguyen Anh Tuan (1), Tran Thi Thuy Nu (1), Nguyen Van
Thanh (1), Vu Van Khai (1,2), Shin-ichi Katayama (3), Nguyen
Huy Sinh (1), Dam Hieu Chi (1,3)
1 Faculty of Physics, Hanoi University of Science, 334 Nguyen Trai,
Thanh Xuan, Hanoi, Vietnam
2 National Univesity of Civil Engineering, 55 Giai Phong, Hai Ba
Trung, Hanoi, Vietnam
3 School of Materials Science, Japan Advanced Institute of Science
and Technology, 1-1, Asahidai, Nomi, Ishikawa, 923-1292 Japan
Tel.: 01234 686969, Email: tuanna@hus.edu.vn; tuanna@vnu.edu.vn
Single-molecule magnets (SMMs) are high-spin molecules that can
function as magnets below their blocking temperature (T B ). They
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