This paper considers a class of oscillator for the El Ni?o/La
Ni?a-southern oscillation (ENSO) model. By using the homotopic
mapping method, it obtains approximations of the solution for the
ENSO model.

A class of generalized Vakhnemko equation is considered.
First, we solve the nonlinear differential equation by the homotopic
mapping method. Then, an approximate soliton solution for
the original generalized Vakhnemko equation is obtained. By this method
an arbitrary order approximation can be easily obtained and,
similarly, approximate soliton solutions of other nonlinear
equations can be acquired.

In this paper we use theoretical analysis and extensive
simulations to study zone inhomogeneity with the random asymmetric
simple exclusion process (ASEP). In the inhomogeneous zone, the
hopping probability is less than 1. Two
typical lattice geometries are investigated here. In case A, the lattice includes two
equal segments. The hopping probability in the left segment is equal
to 1, and in the right segment it is equal to p, which is less than
1. In case B, there are three equal segments in the system; the
hopping probabilities in the left and right segments are equal to
1, and in the middle segment it is equal to p, which is less than
1. Through theoretical analysis, we can discover the effect on these
systems when p is changed.

Variable coefficient nonlinear systems, the Korteweg
de Vries (KdV), the modified KdV (mKdV) and the nonlinear
Schr?dinger (NLS) type equations, are derived from the nonlinear
inviscid barotropic nondivergent vorticity equation in a beta-plane
by means of the multi-scale expansion method in two different ways,
with and without the so-called y-average trick. The
non-auto-B\"acklund transformations are found to transform the
derived variable coefficient equations to the corresponding standard
KdV, mKdV and NLS equations. Thus, many possible exact solutions can
be obtained by taking advantage of the known solutions of these
standard equations. Further, many approximate solutions of the
original model are ready to be yielded which might be applied to
explain some real atmospheric phenomena, such as atmospheric
blocking episodes.

This paper is devoted to studying the conformal invariance
and Noether symmetry and Lie symmetry of a holonomic mechanical
system in event space. The definition of the conformal invariance
and the corresponding conformal factors of the holonomic system in
event space are given. By investigating the relation between the
conformal invariance and the Noether symmetry and the Lie symmetry,
expressions of conformal factors of the system under these
circumstances are obtained, and the Noether conserved quantity and
the Hojman conserved quantity directly derived from the conformal
invariance are given. Two examples are given to illustrate the
application of the results.

This paper studies conformal invariance and generalized
Hojman conserved quantities of mechanico-electrical systems. The
definition and the determining equation of conformal invariance for
mechanico-electrical systems are provided. The conformal factor
expression is deduced from conformal invariance and Lie symmetry
under the infinitesimal single-parameter transformation group. The
generalized Hojman conserved quantities from the conformal
invariance of the system are given. An example is given to
illustrate the application of the result.

This paper studies conformal invariance and conserved
quantity of third-order Lagrange equations for non-conserved
mechanical systems. Third-order Lagrange equations, the definition
and a determining equation of conformal invariance of the system are
presented. The conformal factor expression is deduced from conformal
invariance and Lie symmetry. The necessary and sufficient condition
that conformal invariance of the system would have Lie symmetry under
single-parameter infinitesimal transformations is obtained. The
corresponding conserved quantity of conformal invariance is derived
with the aid of a structure equation. Lastly, an example is given to
illustrate the application of the results.

By using the technique of integration within an ordered
product of operators, the normal ordered density operator of the
photon-subtracted squeezed thermal state (PSSTS) is derived. Then
the corresponding Wigner function is presented by using the coherent
state representation of the Wigner operator. The nonclassical properties
of the PSSTS are discussed based on the negativity of the Wigner
function.

The entanglement property of two identical atoms,
initially entangled in Bell states, coupled to a single-mode cavity
is considered. Based on the reduced non-perturbative quantum master
equation method, the entanglement evolution of the two atoms with
decay is investigated beyond the conventional rotating-wave
approximation. We show that the counter-rotating wave terms,
usually neglected, have a great influence on the disentanglement
behaviour of the system. The phenomena of entanglement sudden death
and entanglement sudden birth will occur. In addition, we show that
the entanglement can be strengthened by introducing the
dipole--dipole interaction of the two atoms.

This paper presents a finite element calculation for the
electronic structure and strain distribution of self-organized
InAs/GaAs quantum rings. The strain distribution calculations are
based on the continuum elastic theory. An ideal three-dimensional
circular quantum ring model is adopted in this work. The electron
and heavy-hole energy levels of the InAs/GaAs quantum rings are
calculated by solving the three-dimensional effective mass
Schr?dinger equation including the deformation potential and
piezoelectric potential up to the second order induced by the
strain. The calculated results show the importance of strain and
piezoelectric effects, and these effects should be taken into
consideration in analysis of the optoelectronic characteristics of
strain quantum rings.

We examine the entanglement dynamics between two strongly
driven atoms off-resonantly coupled with a single-mode cavity via
the two-photon process with the help of negativity in two different
types of initial states. The results show that entanglement sudden
death may occur under both the above conditions and the sudden death
effect can be monitored by modulating the atom--cavity detunings.
Furthermore, we also find an atomic decoherence-free subspace so
that the initial entanglement between two atoms remains invariable
in application.

A scheme for approximate generation of an N-qubit phase
gate is proposed in cavity QED based on nonidentical coupling
between the atoms and the cavity. The atoms interact with a highly
detuned cavity-field mode, but quantum information does not transfer
between the atoms and cavity field, and thus the cavity decay is
negligible. The gate time does not rise with an increase in the
number of qubits. With the choice of a smaller odd number l
(related to atom--cavity coupling constants), the phase gate can be
generated with a higher fidelity and a higher success probability in
a shorter time (the gate time is much shorter than the atomic radiative
lifetime and photon lifetime). When the number of qubits N exceeds
certain small values, the fidelity and success probability rise
slowly with an increase in the number of qubits N. When
N\rightarrow\infty, the fidelity and success probability
infinitely approach 1, but never exceed 1.

This paper presents a scheme for high-capacity three-party
quantum secret sharing with quantum superdense coding, following
some ideas in the work by Liu et al (2002 Phys. Rev. A
65 022304) and the quantum secret sharing scheme by Deng
et al (2008 Phys. Lett. A 372 1957). Instead of using
two sets of nonorthogonal states, the boss Alice needs only to
prepare a sequence of Einstein--Podolsky--Rosen pairs in
d-dimension. The two agents Bob and Charlie encode their
information with dense coding unitary operations, and security is
checked by inserting decoy photons. The scheme has a high capacity
and intrinsic efficiency as each pair can carry 2lbd bits of
information, and almost all the pairs can be used for carrying
useful information.

This paper presents a treatment of the entanglement
transfer between atoms in two distant cavities coupled by an optical
fibre. If the atoms resonantly and collectively interact with the
local single-mode cavity fields and the dipole--dipole interaction
between the atoms is neglected, then it shows that a complete
transfer of entanglement from one pair of atoms to another can be
deterministically realized. Furthermore, it also investigates the
effects of dipole--dipole interaction on entanglement transfer on
the condition that the interaction between the atoms and the cavity
is much weaker than the coupling between the cavity and the fibre.

Polarization filtering and atomic cell filtering
are applied in the identification of Stokes signals in an atomic
ensemble, and reduce the noise to a level of 10^ - 5 and 10^
- 4 respectively. Good Stokes signals are then obtained. In this
article the two filtering systems and the final Stokes output
are presented, and the optimization of the polarization filtering
system is highlighted.

We numerically study the fidelity of an electron in the
one-dimensional Harper model and in the one-dimensional slowly
varying potential model. Our results show that many properties of
the two models can be well reflected by the fidelity: (i) the mobility
edge and metal--insulator transition can be characterized by the
static fidelity; (ii) the extended state and localized state can be
identified by the dynamic fidelity. Therefore, it may broaden the
applied areas of the fidelity.

Following a recent proposal by Dhar et al (2006
Phys. Rev. Lett. 96 100405), we demonstrate experimentally
the preservation of quantum states in a two-qubit system based on a
super-Zeno effect using liquid-state nuclear magnetic resonance
techniques. Using inverting radiofrequency pulses and delicately
selecting time intervals between two pulses, we suppress the effect
of decoherence of quantum states. We observe that preservation of
the quantum state |11\rg with the super-Zeno effect is three times
more efficient than the ordinary one with the standard Zeno effect.

This paper discusses tunneling of scalar particles and
Dirac particles from the Taub-NUT-AdS black hole by the
Hamilton--Jacobi equation, initially used by Angheben et al,
and the Dirac equation, recently proposed by Kerner and Mann.
This is performed in the dragging coordinate frame so
as to avoid the ergosphere dragging effect. A general
form is obtained for the temperature of scalar and Dirac particles tunneling
from the Taub-NUT-Ads black hole, which is commensurate with other
methods as expected.

Introducing a new coordinate system and choosing a set of
appropriate matrices γ^μ , this paper attempts to
investigate the fermion tunneling of charged particles across the
event horizon from the Vaidya--Bonner de Sitter black hole. The result
shows that the tunneling rate of the non-static black hole is
related not only to the change of Bekenstein--Hawking entropy but
also to the integral of the changing horizon, which violates
unitary theory and is different from the stationary case.

This paper investigates the dynamics of dark solitons in a
Bose--Einstein condensate with a magnetic trap and an optical
lattice (OL) trap, and analyses the effects of the periodic OL
potential on the dynamics by applying the variational approach based
on the renormalized integrals of motion. The results show that the
dark soliton becomes only a standing-wave and free propagation
of the dark soliton is not possible when the periodic length of the
OL potential is approximately equal to the effective width of the
dark soliton. When the periodic length is very small or very large,
the effects of the OL potential on the dark soliton will be sharply
reduced. Finally, the numerical results confirm these theoretical
findings.

In this paper, with the full field operator \hat ψ
expressed in terms of a particle-number-conserving mean-field ansatz,
we investigate the dynamical behaviour of Bose--Einstein condensates
from microscopic physics. Including the first-order term
correction from single-particle excitation and the remaining
higher-order term correction from collective excitations
simultaneously, we obtain the formulation for a closed local
expression of quantum backreaction Q, and discuss the influence on
static Bose--Einstein condensates. Even though the quantum
backreaction is small, it still has some influence on its dynamics.

The nonequilibrium phase transition and the symmetry
revival induced by time delay in a bistable system are investigated.
The stationary probability distribution function (SPDF) of the
bistable system with time delay and correlated noises are calculated
by an analytical method and stochastic simulation respectively. The
analytical and simulative results indicate that: (1) There is a
certain value of λ (λ denotes the strength of
correlations between the multiplicative and additive noises) to make
the SPDF symmetric under some time delay; however, above or below
the given value, the symmetry will be broken; (2) With the
monotonic change of λ , the unimodal peak structure of SPDF
becomes bimodal at the beginning, then it becomes unimodal again; this
means that there is a reentrance phenomenon in the process; (3)
There is a critical value of delay time, which makes the lower peak
of SPDF equal to the higher one under the critical condition. This
means that the symmetry revival phenomenon emerges.

By establishing the discrete iterative mapping model of a
current mode controlled buck-boost converter, this paper studies the
mechanism of mode shift and stability control of the buck-boost
converter operating in discontinuous conduction mode with a ramp
compensation current. With the bifurcation diagram, Lyapunov
exponent spectrum, time-domain waveform and parameter space map, the
performance of the buck-boost converter circuit utilizing a
compensating ramp current has been analysed. The obtained results
indicate that the system trajectory is weakly chaotic and strongly
intermittent under discontinuous conduction mode. By using ramp
compensation, the buck-boost converter can shift from discontinuous
conduction mode to continuous conduction mode, and effectively
operates in the stable period-one region.

This paper applies washout filter technology to amplitude
control of limit cycles emerging from Hopf bifurcation of the van der
Pol--Duffing system. The controlling parameters for the appearance
of Hopf bifurcation are given by the Routh--Hurwitz criteria.
Noticeably, numerical simulation indicates that the controllers
control the amplitude of limit cycles not only of the weakly nonlinear van
der Pol--Duffing system but also of the strongly nonlinear van der
Pol--Duffing system. In particular, the emergence of Hopf bifurcation
can be controlled by a suitable choice of controlling parameters.
Gain-amplitude curves of controlled systems are also drawn.

In this article, we investigate cascading failures in
complex networks by introducing a feedback. To characterize the
effect of the feedback, we define a procedure that involves a
self-organization of trip distribution during the process of
cascading failures. For this purpose, user equilibrium with variable
demand is used as an alternative way to determine the traffic flow
pattern throughout the network. Under the attack, cost function
dynamics are introduced to discuss edge overload in complex networks,
where each edge is assigned a finite capacity (controlled by
parameter α). We find that scale-free networks without
considering the effect of the feedback are expected to be very
sensitive to α as compared with random networks, while this
situation is largely improved after introducing the feedback.

Network traffic prediction models can be grouped into two
types, single models and combined ones. Combined models integrate
several single models and thus can improve prediction accuracy.
Based on wavelet transform, grey theory, and chaos theory, this
paper proposes a novel combined model, wavelet--grey--chaos (WGC),
for network traffic prediction. In the WGC model, we develop a time
series decomposition method without the boundary problem by modifying
the standard \grave\rm a trous algorithm, decompose the network
traffic into two parts, the residual part and the burst part to
alleviate the accumulated error problem, and employ the grey model
GM(1,1) and chaos model to predict the residual part and the
burst part respectively. Simulation results on real network
traffic show that the WGC model does improve prediction accuracy.

Computational analysis of electrostatic
microelectromechanical systems (MEMS) requires an electrostatic
analysis to compute the electrostatic forces acting on
micromechanical structures and a mechanical analysis to compute the
deformation of micromechanical structures. Typically, the mechanical
analysis is performed on an undeformed geometry. However, the
electrostatic analysis is performed on the deformed position of
microstructures. In this paper, a new efficient approach to
self-consistent analysis of electrostatic MEMS in the small
deformation case is presented. In this approach, when the
microstructures undergo small deformations, the surface charge
densities on the deformed geometry can be computed without updating
the geometry of the microstructures. This algorithm is based on the
linear mode shapes of a microstructure as basis functions. A boundary
integral equation for the electrostatic problem is expanded into a
Taylor series around the undeformed configuration, and a new
coupled-field equation is presented. This approach is validated by
comparing its results with the results available in the literature
and ANSYS solutions, and shows attractive features comparable to
ANSYS.

A novel dual-emitter vacuum Compton detector (D-VCD) with
higher gamma ray detecting efficiency is proposed. The emitters are
made of Ta--Al clad metal. The gamma ray sensitivity is studied by
Monte Carlo simulation using the MCNP code. A comparison
between calculations and results measured by using the 1.25~MeV
gamma ray of Co-60 is also performed. Experimental sensitivities for
two sample D-VCDs with the same materials and structures are
1.92×10^ - 20 and 2.02×10^ -
20~C.cm^{2}/MeV separately, which are consistent with
the simulation result of 1.98×10^ -
20~C.cm^{2}/MeV and are 4 times higher than that of
VCD with a single Fe emitter. According to the simulation results, in
a gamma energy range from 0.5 to 3~MeV, the maximum sensitivity
variance for the D-VCD is less than 15%, and less than 5% in a
range from 1 to 2~MeV in particular. The novel D-VCD is applicable to
the detection of intense pulse gamma rays.

The 140~MeV/u ^40,48Ca+^9Be and ^58,64Ni+^9Be
reactions are simulated by the statistical abrasion ablation model,
and the simulation results are compared to the National
Superconducting Cyclotron Laboratory (NSCL) experimental data. By
comparing the fragment isotopic distributions of ^40,48Ca and
^58,64Ni, we study the isospin effect in the projectile
fragmentation induced by the neutron-rich nuclei at intermediate
energy experimentally and theoretically. It is found that the
isospin effect in projectile fragmentation decreases and even
disappears as the violence of the collision increases.

The particle spectra and Hanbury-Brown Twiss (HBT) radius
of Au+Au collisions at RHIC energy are investigated by a
hydrodynamical expanding source with both shear and bulk viscosities
(ζ). With a large width of the ratio of ζ to entropy
density s, both the particle transverse momentum spectra and the
ratio R_\rm out/R_\rm side of HBT radii in the direction of
the total transverse momentum of detected two particles (R_\rm
out) and perpendicular to both this direction and the beam
direction (R_\rm side) become a little steeper.

We observe strong energy-dependent quantum defects in the
scaled-energy Stark spectra for |M|=1 Rydberg states of barium
atoms at three scaled energies: ε=-2.000,
ε=-2.500 and ε=-3.000. In an attempt to
explain the observations, theoretical calculations of closed orbit
theory based on a model potential including core effect are
performed for non-hydrogenic atoms. While such a potential has been
uniformly successful for alkali atoms with a single valence
electron, it fails to match experimental results for barium atoms in
the 6sNp Rydberg states with two valence electrons. Our study
points out that this discrepancy is due to the strong perturbation
from the 5d8p state, which voids the simple approximation for
constant quantum defects of principle quantum number N.

A modified correlated spectroscopy (COSY) revamped with
asymmetric Z-gradient echo detection sequence was designed to
investigate the influence of diffusion behaviour on intermolecular
double-quantum coherence signal attenuation during the
pre-acquisition period. Theoretical formulas were deduced and
experimental measurements and simulations were performed. It is
found that the diffusion behaviour of intermolecular double-quantum
coherence in the pre-acquisition period may be different from that of
conventional single-quantum coherence, depending on the relative
orientation of diffusion weighting gradients to coherence selection
gradients. When the orientation of the diffusion weighting gradients is
parallel or anti-parallel to the orientation of the coherence
selection gradients, the diffusion is modulated by the distant
dipolar field. This study is helpful for understanding the signal
properties in intermolecular double-quantum coherence magnetic
resonance imaging.

We investigate the ionization dynamics of atoms by chirped
attosecond pulses using the strong field approximation method. The
pulse parameters are carefully chosen in the regime where the strong
field approximation method is valid. We analyse the effects of the
chirp of attosecond pulses on the energy distributions and the
corresponding left-right asymmetry of the ionized electrons. For a
single chirped attosecond pulse, the ionized electrons can be
redistributed and the left-right asymmetry shows oscillations
because of the introduction of the chirp. For time-delayed double
attosecond pulses at different intensities with the weaker one
chirped, exchanging the order of the two pulses shows a relative
shift of the energy spectra, which can be explained by the different
effective time delays of different frequency components because of
the chirp.

The photoelectron angular distributions (PADs) of hydrogen
atoms in an intense laser field of linear polarization are studied
using the S-matrix theory in the length gauge. The PADs show main
lobes along the laser polarization and jet-like structures sticking
from the waist of main lobes. Our previous prediction, based on a
nonperturbative scattering theory of photoionization developed by
Guo et al, showing that the number of jets on one side of PADs
may increase by one, three, or other odd numbers and may decrease by one
when one more photon is absorbed, is confirmed by this treatment.
Within the strong-field approximation, good agreement is obtained
between these two quite different treatments. We further study the
influence of the Coulomb attraction to PADs, by taking a
Coulomb--Volkov state as the continuum state of photoelectrons. We
find that under the influence of the Coulomb attraction, the PADs
change greatly but the predicted phenomena still appear. This study
verifies that the jet-like structures have no relation with the
angular momentum of photoelectrons.

Chip-based atom interferometers bring together the
advantages of atom chips and Bose--Einstein condensates. Their central
prerequisite is that a condensate can be coherently split into two
halves with a determined relative phase. This paper demonstrates the
dynamical splitting and merging of an atom cloud with two U-wires on
an atom chip. Symmetrical and asymmetrical splittings are realized
by applying a bias field with dif\/ferent directions and
magnitudes. The trajectories of the splitting are consistent with
theoretical calculations. The atom chip is a good candidate for
constructing an atom interferometer.

Thin ferromagnetic films with in-plane magnetic anisotropy
are promising materials for obtaining high microwave permeability.
The paper reports a M?ssbauer study of the field induced
in-plane uniaxial anisotropy in electro-deposited FeCo alloy films.
The FeCo alloy films were prepared by the electro-deposition method
with and without an external magnetic field applied parallel to the
film plane during deposition. Vibrating sample magnetometry and
M?ssbauer spectroscopy measurements at room temperature indicate
that the film deposited in external field shows an in-plane uniaxial
anisotropy with an easy direction coinciding with the external field
direction and a hard direction perpendicular to the field direction,
whereas the film deposited without external field does not show any
in-plane anisotropy. M?ssbauer spectra taken in three geometric
arrangements show that the magnetic moments are almost constrained
in the film plane for the film deposited with applied magnetic
field. Also, the magnetic moments tend to align in the direction
of the applied external magnetic field during deposition, indicating
that the observed anisotropy should be attributed to directional
ordering of atomic pairs.

The interference between two dissociating wave packets of
the \textrmI_{2} molecule driven by femtosecond laser pulses is
theoretically studied by using the time-dependent quantum wave packet
method. Both the internuclear distance- and velocity-dependent
density functions are calculated and discussed. It is demonstrated
that the interference pattern is determined by the phase difference
and the delay time between two pump pulses. With two identical
pulses with a delay time of 305~fs and a FWHM of 20~fs, more
interference fringes can be observed, while with two pump pulses
with a delay time of 80~fs and a FWHM of 20~fs, only a few
interference fringes can be observed.

A new theoretical model of the triatomic molecular wake effect
is proposed and applied to molecular ions D_{3}^{+} and
HD_{2}^{+} while passing through a solid. The wake effects
resulting from the reactions of the two similar ions with thin carbon
foil are also investigated by using the Coulomb explosion technique. The
experimental results are in good agreement with theoretical
estimates and the molecular structure of HD_{2}^{+} is
determined by using the model.

This paper introduces a correlation--polarization potential
with high order terms for vibrational excitation in
electron--molecule
scattering. The new polarization potential generalizes the two-term
approximation so that it can better reflect the dependence of
correlation and polarization effects on the position coordinate of
the scattering electron. It applies the new potential on the
vibrational excitation scattering from N_{2} in an energy range
which
includes the ^{2}П_{g} shape resonance. The good agreement of
theoretical resonant peaks with experiments shows that polarization
potentials with high order terms are important and should be
included in vibrational excitation scattering.

During the assembly of many viruses, a powerful molecular
motor packages the genome into a preassembled capsid. The Bacillus
subtilis phage φ 29 is an excellent model system to investigate
the DNA packaging mechanism because of its highly efficient
\textitin vitro DNA packaging activity and the development of a
single-molecule packaging assay. Here we make use of structural and
biochemical experimental data to build a physical model of DNA
packaging by the φ 29 DNA packaging motor. Based on the model,
various dynamic behaviours such as the packaging rate, pause
frequency and slip frequency under different ATP concentrations, ADP
concentrations, external loads as well as capsid fillings are
studied by using Monte Carlo simulation. Good agreement is obtained
between the simulated and available experimental results. Moreover,
we make testable predictions that should guide future experiments
related to motor function.

Symmetric tapered dielectric structures in metal have
demonstrated applications such as the nanofocusing of surface
plasmon polaritons, as well as the waveguiding of V-channel
polaritons. Yet the fabrication of smooth-surfaced tapered structure
remains an obstacle to most researchers. We have successfully
developed a handy method to fabricate metal-sandwiched tapered
nanostructures simply with electron beam lithography. Though these
structures are slightly different from conventional symmetric
V-shaped structures, systematic simulations show that similar
functionality of surface plasmon polariton nanofocusing can still be
achieved. When parameters are properly selected,
wavelength-selective nanofocusing of surface plasmon polaritons can
be obtained.

This paper describes a multi-reflected mode based on a
narrow waveguide to enlarge the interferential area of surface
plasmon polaritons (SPPs). A reasonable thickness of metal film is
coated under the waveguide, the incident angle and the waveguide
thickness are optimized in order to effectively increase
interferential area. This is a key point for research into the
Goos--H\"anchen shift to optimize the waveguide thickness. Finally,
the SPP interferential field is simulated with the finite-difference
time-domain (FDTD) technique to prove the optimized results, and
indicates that not only is the interferential area enlarged, but
the high contrast is also maintained. Furthermore, the mode can
fabricate some specific interferential patterns by adding some
modulating techniques to the waveguide. So the mode has potential
application in the fabrication of sub-wavelength patterns.

This paper reports that Goos--H\"anchen (GH) shifts
occurring on a symmetrical metal-cladding waveguide are
experimentally identified. It was found that there exists a critical
thickness of the upper metal layer, h_cr, above which negative
shift is observed and, reversely, positive shift occurs. Both
positive and negative GH shifts near the critical thickness do not vary
dramatically and can achieve a maximum on the submillimeter scale, which
is different from simulated results using the stationary-phase
method. It also shows that this critical thickness, h_cr, can be
obtained at the position for zero reflectivity by setting the
intrinsic damping to be the same as the radiative damping. The GH
effects observed near the critical thickness are produced by extreme
distortion of the reflected beam profiles, which limits the
amplitude of the GH shift and, further, the sensitivity of the GH optical
sensor based on the symmetrical metal-cladding waveguide.

The dual-frequency grating measurement theory is
proposed in order to carry out the measurement of a discontinuous
object. Firstly, the reason why frequency spectra are produced by
low frequency gratings and high frequency gratings in the field of
frequency is analysed, and the relationship between the wrapped-phase and
the unwrapping-phase is discussed. Secondly, a method to combine the
advantages of the two kinds of gratings is proposed: one stripe is
produced in the mutation part of the object measured by a suitable
low frequency grating designed by MATLAB, then the phase produced by
the low frequency grating need not be unfolded. The integer series of
stripes is produced by a high frequency grating designed by MATLAB
based on the frequency ratio of the two kinds of gratings and the
high frequency wrapped-phase, and the high frequency unwrapping-phase
is then obtained. In order to verify the correctness of the
theoretical analysis, a steep discontinuous object of 600×600
pixels and 10.00~mm in height is simulated and a discontinuous object
of ladder shape which is 32.00~mm in height is used in experiment.
Both the simulation and the experiment can restore the discontinuous
object height accurately by using the dual-frequency grating measurement theory.

A new kind of quantum optical state, photon-added and
-subtracted displaced Fock states, is introduced by applying the
inverse of bosonic creation and annihilation operators to
displaced Fock states. The quantum statistical properties of these
states are investigated by numerical methods. Numerical results
indicate that these states reveal some interesting non-classical
properties, such as anti-bunching effects, sub-Poisson
distributions and negativities of their Wigner
functions.

We explore the possibility of an N-qubit (N>3) Grover
search in cavity QED, based on a fast operation of an N-qubit
controlled phase-flip with atoms in resonance with the cavity mode.
We demonstrate both analytically and numerically that our scheme
can be achieved efficiently to find a marked state with high
fidelity and high success probability. As an example, a ten-qubit
Grover search is simulated specifically under the discussion of
experimental feasibility and challenge. We argue that our scheme is
applicable to the case involving an arbitrary number of qubits. As
cavity decay is involved in our quantum trajectory treatment, we
can analytically understand the implementation of a Grover search
subject to dissipation, which will be very helpful for relevant
experiments.

We theoretically analysed the linewidth of the probe
absorption spectrum in a cold Cs atom--molecule system. The
tunnelling coupling between the two excited molecular states,
especially for the Cs atom--molecule system, plays an important role in
obtaining the sub-natural linewidth of the probe absorption spectrum.
For example, when the tunnelling couple strength fulfils \sigma
_12=10γ _ab_{1}, the linewidth is only about 0.66~MHz.
Moreover, since the linewidth of interest is dominated by the
tunnelling coupling, the absorption peak becomes very narrow even in
the case of large pump laser intensities.

Si^{+} ion-implanted silicon wafers are annealed
at different temperatures from room temperature to 950~℃ and then
characterized by using the photoluminescence (PL) technique at
different recorded temperatures (RETs). Plentiful optical features
are observed and identified clearly in these PL curves. The PL
spectra of these samples annealed in different temperature ranges
are correspondingly dominated by different emission peaks. Several
characteristic features, such as an R line, S bands, a W line, the
phonon-assistant W^\rm TA and Si^\rm TO peaks, can be
detected in the PL spectra of samples annealed at different
temperatures. For the samples annealed at 800~\du, emission
peaks from the dislocations bounded at the deep energy levels of the
forbidden band, such as D_1 and D_{2} bands, can be observed at a
temperature as high as 280~K. These data strongly indicate that a
severe transformation of defect structures could be manipulated by
the annealing and recorded temperatures. The deactivation energies of
the main optical features are extracted from the PL data at
different temperatures.

The intrinsic features involving a circularly symmetric beam
profile with low divergence, planar geometry as well as the increasingly
enhanced power of vertical-cavity surface-emitting lasers (VCSELs)
have made the VCSEL a promising pump source in direct end bonding to
a solid-state laser medium to form the minimized, on-wafer
integrated laser system. This scheme will generate a surface contact
pump configuration and thus additional end thermal coupling to the
laser medium through the joint interface of both materials, apart from
pump beam heating. This paper analytically models temperature
distributions in both VCSEL and the laser medium from the end thermal
coupling regarding surface contact pump configuration using a
top-emitting VCSEL as the pump source for the first time. The
analytical solutions are derived by introducing relative temperature
and mean temperature expressions. The results show that the end
contact heating by the VCSEL could lead to considerable temperature
variations associated with thermal phase shift and thermal lensing
in the laser medium. However, if the central temperature of the
interface is increased by less than 20~K, the end contact heating
does not have a significant thermal influence on the laser medium. In
this case, the thermal effect should be dominated by pump beam
heating. This work provides useful analytical results for further
analysis of hybrid thermal effects on those lasers pumped by a direct
VCSEL bond.

We analyse surface solitons at the interface between a
one-dimensional photonic superlattice and a uniform medium with weak
nonlocal nonlinearity. We demonstrate that in deep lattices there
exist three kinds of surface solitons when the propagation constant
exceeds a critical value, including two on-site solitons and one
off-site soliton. These three kinds of surface solitons have unique
dynamical properties. If the relative depth of the superlattice is low,
there is only one kind of off-site soliton; however, the solitons of
this kind can propagate stably, unlike their deep superlattice
counterparts. Dipole surface solitons are also investigated, and the
stable domain is given.

We theoretically study the beam dynamical behaviour in a
modulated optical lattice with a quadratic potential in a
photovoltaic photorefractive crystal. We find that two different
Bloch oscillation patterns appear for the excitation of both broad
and narrow light beams. One kind of optical Landau--Zener tunnelling
also appears upon the Bloch oscillation and can be controlled by
adjusting the parameter of the optical lattice. Unlike the case of
linear potential, the energy radiation due to Landau--Zener
tunnelling can be confined in modulated lattices of this kind. For
high input intensity levels, the Landau--Zener tunnelling is
suppressed by the photovoltaic photorefractive nonlinearity and a
symmetry breaking of beam propagation from the modulational
instability appears.

This article theoretically studies the influence of
inhomogeneous abdominal walls on focused therapeutic ultrasound
based on the phase screen model. An inhomogeneous tissue is
considered as a combination of a homogeneous medium and a phase
aberration screen. Variations of acoustic parameters such as peak
positive pressure, peak negative pressure, and acoustic intensity
are discussed with respect to the phase screen statistics of
human abdominal walls. Results indicate that the abdominal wall can
result in energy loss of the sound in the focal plane. For a
typical human abdominal wall with correlation length of 7.9~mm and
variance of 0.36, the peak acoustic intensity radiated from a 1~MHz
transmitter with a radius of 30~mm can be reduced by about 14% at
the focal plane.

PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES

Dispersion relation matrices, with the screened Coulomb
interaction between a charged dust particle and all other particles
taken into account, are derived for waves in body centred cubic
(bcc) and face centred cubic (fcc) lattices in three-dimensional
strongly coupled complex plasma crystals separately. The matrices
are then calculated in characteristic directions to obtain the
longitudinal and transverse eigenmodes. The longitudinal and
transverse waves for these cases are discussed separately.

CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES

X-ray powder diffraction, resistivity and magnetization
studies have been performed on polycrystalline Nd(Fe_{x}Mn_1
- x)_{2}Si_{2} (0 ≤ x ≤ 1) compounds which crystallize in
a ThCr_{2}Si_{2}-type structure with the space group I4/mmm.
The field-cooled temperature dependence of the magnetization curves
shows that, at low temperatures, NdFe_{2}Si_{2} is
antiferromagnetic, while the other compounds show ferromagnetic
behaviour. The substitution of Fe for Mn leads to a decrease in
lattice parameters a, c and unit-cell volume V. The Curie
temperature of the compounds first increases, reaches a maximum
around x=0.7, then decreases with Fe content. However, the
saturation magnetization decreases monotonically with increasing Fe
content. This Fe concentration dependent magnetization of
Nd(Fe_{x}Mn_{1-x})_{2}Si_{2} compounds can be well explained
by taking into account the complex effect on magnetic properties due
to the substitution of Mn by Fe. The temperature's square dependence on
electrical resistivity indicates that the curve of
Nd(Fe_0.6Mn_0.4)_{2}Si_{2} has a quasi-linear character
above its Curie temperature, which is typical of simple metals.

This paper reports that anomalous local order in
liquid and glassy AlFeCe alloy has been detected by x-ray
diffraction measurements. The addition of the element Ce has a great
effect on this local structural order. The element Ce favours
interpenetration of the icosahedra by sharing a common face and
edges. It argues that frustration between this short-range order
and the long-range crystalline order controls the glass-forming
ability of these liquids. The obtained results suggest that a system
having a stronger tendency to show local icosahedral order should be
a better glass-former. This scenario also naturally explains the
close relationship between the local icosahedral order in a liquid,
glass-forming ability, and the nucleation barrier. Such topological
local order has also been analysed directly using the reverse Monte
Carlo method. It also estimated the fraction of local ordered and
disordered structural units in a glassy AlFeCe alloy.

This paper uses a molecular static approach with a
many-body potential to investigate the surface energetic and bonding
characteristics of tetrahexahedral platinum nanocrystals enclosed by
high-index facets such as 210, 310, 410,
520 and 730. It mainly focuses on the effect of
crystal size and surface Miller index on these characteristics. The
results show that the surface energy and dangling bond density
increase with decreasing diameter of tetrahexahedral nanocrystals and
generally show an order of 210 > 730 >
520 > 310 > 410. However, this order is not
valid at crystal sizes below 7~nm or so. The results of corresponding
surfaces are also presented for comparison.

NiZn ferrite/polyvinylpyrrolidone composite fibres were
prepared by sol--gel assisted electrospinning.
Ni_{0.5}Zn_{0.5}Fe_{2}O_{4} nanofibres with a pure cubic
spinel structure were obtained subsequently by calcination of the
composite fibres at high temperatures. This paper investigates the
thermal decomposition process, structures and morphologies of the
electrospun composite fibres and the calcined
Ni_{0.5}Zn_{0.5}Fe_{2}O_{4} nanofibres at different
temperatures by thermo-gravimetric and differential thermal
analysis, x-ray diffraction, Fourier transform infrared spectroscopy
and field emission scanning electron microscopy. The magnetic
behaviour of the resultant nanofibres was studied by a vibrating
sample magnetometer. It is found that the grain sizes of the nanofibres
increase significantly and the nanofibre morphology gradually
transforms from a porous structure to a necklace-like nanostructure
with the increase of calcination temperature. The
Ni_{0.5}Zn_{0.5}Fe_{2}O_{4} nanofibres obtained at 1000~℃
for 2~h are characterized by a necklace-like morphology and
diameters of 100--200~nm. The saturation magnetization of the random
Ni_{0.5}Zn_{0.5}Fe_{2}O_{4} nanofibres increases from 46.5
to 90.2~emu/g when the calcination temperature increases from 450 to
1000~\du. The coercivity reaches a maximum value of 11.0~kA/m at a
calcination temperature of 600~\du. Due to the shape anisotropy, the
aligned Ni_{0.5}Zn_{0.5}Fe_{2}O_{4} nanofibres exhibit an
obvious magnetic anisotropy and the ease magnetizing direction is
parallel to the nanofibre axis.

The Si on SiC heterojunction is still poorly understood,
although it has a number of potential applications in electronic and
optoelectronic devices, for example, light-activated SiC power
switches where Si may play the role of an light absorbing layer. This
paper reports on Si films heteroepitaxially grown on the Si face of
(0001) n-type 6H-SiC substrates and the use of B_{2}H_6 as a
dopant for p-Si grown at temperatures in a range of
700--950~\du. X-ray diffraction (XRD) analysis and transmission
electron microscopy (TEM) tests have demonstrated that the samples
prepared at the temperatures ranged from 850~℃ to 900~℃ are
characterized as monocrystalline silicon. The rocking XRD curves
show a well symmetry with FWHM of 0.4339° Omega. Twin
crystals and stacking faults observed in the epitaxial layers might
be responsible for widening of the rocking curves. Dependence of the
crystal structure and surface topography on growth temperature is
discussed based on the experimental results. The energy band structure
and rectifying characteristics of the Si/SiC heterojunctions are
also preliminarily tested.

This paper reports on a comparative study of the spatial
distributions of the electrical, optical, and structural properties
in an AlGaN/GaN heterostructure. Edge dislocation density in the GaN
template layer is shown to decrease in the regions of the wafer
where the heterostructure sheet resistance increases and the GaN
photoluminescence band-edge energy peak shifts to a high wavelength.
This phenomenon is found to be attributed to the local compressive
strain surrounding edge dislocation, which will generate a local
piezoelectric polarization field in the GaN layer in the opposite
direction to the piezoelectric polarization field in the AlGaN layer and
thus help to increase the two-dimensional electron gas
concentration.

This paper studies numerically the thermo-mechanical
effects of ZrO_{2} thermal barrier coatings (TBCs) irradiated by
a high-intensity pulsed ion beam in consideration of the surface
structure. Taking the deposited energy of ion beams in TBCs as the
source term in the thermal conduction equation, the distribution of
temperature in TBCs was simulated. Then, based on the
distribution, the evolution of thermal stress was calculated by the
finite element method. The results show that tensile radial stress
formed at the valley of TBC surfaces after irradiation by HIPIB.
Therefore, if cracks happen, they must be at valleys instead of
peaks. As for the stress waves, no matter whether through peak or valley
position, tensile and compressive stresses are present alternately
inside TBCs along the depth direction, and the strength of stress
decreases with time.

This paper calculates the elastic, thermodynamic and
electronic properties of pyrite (Pa\bar 3) RuO_{2} by the
plane-wave pseudopotential density functional theory (DFT) method.
The lattice parameters, normalized elastic constants, Cauchy
pressure, brittle--ductile relations, heat capacity and Debye
temperature are successfully obtained. The Murnaghan equation of
state shows that pyrite RuO_{2} is a potential superhard material.
Internal coordinate parameter increases with pressure, which
disagrees with experimental data. An analysis based on electronic
structure and the pseudogap reveals that the bonding nature in RuO_{2}
is a combination of covalent, ionic and metallic bonding. A study of
the elastic properties indicates that the pyrite phase is isotropic under
usual conditions. The relationship between brittleness and ductility shows
that pyrite RuO_{2} behaves in a ductile matter at zero pressure
and the degree of ductility increases with pressure.

Using a first-principles approach based on density
functional theory, this paper studies the electronic and dynamical
properties of β-V_{2}O_5. A smaller band gap and much
wider split-off bands have been observed in comparison with α
-V_{2}O_5. The Raman- and infrared-active modes at the
\varGamma point of the Brillouin zone are evaluated with LO/TO
splitting, where the symbol denotes the longitudinal and transverse
optical model. The nonresonant Raman spectrum of a β-V_{2}O_5
powder sample is also computed, providing benchmark theoretical
results for the assignment of the experimental spectrum. The computed
spectrum agrees with the available experimental data very well. This
calculation helps to gain a better understanding of the transition
from α - to β-V_{2}O_5.

Based on the heat diffusion equation of multilevel
interconnects, a novel analytical thermal model for multilevel
nano-scale interconnects considering the via effect is presented,
which can compute quickly the temperature of multilevel
interconnects, with substrate temperature given. Based on the
proposed model and the 65~nm complementary metal oxide semiconductor
(CMOS) process parameter, the temperature of nano-scale
interconnects is computed. The computed results show that the via
effect has a great effect on local interconnects, but the reduction
of thermal conductivity has little effect on local interconnects.
With the reduction of thermal conductivity or the increase of
current density, however, the temperature of global interconnects
rises greatly, which can result in a great deterioration in their
performance. The proposed model can be
applied to computer aided design (CAD) of very large-scale
integrated circuits (VLSIs) in nano-scale technologies.

CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES

Constant temperature and pressure molecular dynamics
(MD) simulations are performed to investigate the thermal
expansivity of MgO at high pressure, by using effective
pair-wise potentials which consist of Coulomb, dispersion, and
repulsion interactions that include polarization effects through the
shell model (SM). In order to take into account non-central forces
in crystals, the breathing shell model (BSM) is also introduced into
the MD simulation. We present a comparison between the volume
thermal expansion coefficient α dependences of pressure P
at 300 and 2000~K that are obtained from the SM and BSM potentials
and those derived from other experimental and theoretical methods in
the case of MgO. Compared with the results obtained by using the SM
potentials, the MD results obtained by using BSM potentials are more
compressible. In an extended pressure and temperature range, the α
value is also predicted. The properties of MgO in a
pressure range of 0--200~GPa at temperatures up to 3500~K are summarized.

Using density-functional calculations within the
generalized gradient approximation (GGA)+U framework, we
investigate the structural, electronic, and magnetic properties of
the ground states of SrFeO_{n} (n=2 and 2.5). The magnetism
calculations show that the ground states of both SrFeO_{2} and
SrFeO_2.5 have G type antiferromagnetic ordering, with indirect
band gaps of 0.89 and 0.79~eV, respectively. The electronic
structure calculations demonstrate that Fe cations are in the
high-spin state of
(d_z^{2})^{2}(d_xz,d_yz)^{2}(d_xy)^{1}(d_x^{2}-y^{2})^{1}(S=2),
unlike the previous prediction of
(d_xz,d_yz)^{3}(d_xy)^{1}(d_z^{2})^{1}(d_x^{2}-y^{2})^{1}(S=2)
for SrFeO_{2}, and in the high-spin state of
(d_xy,d_xz,d_yz,d_x^{2}-y^{2},d_z^{2})^5(S=5/2)
for SrFeO_2.5.

The displacement damage dose methodology for analysing and
modelling the performance of triple-junction InGaP_{2}/GaAs/Ge
solar cells in an electron radiation environment is presented.
Degradations at different electron energies are correlated with
displacement damage dose (D_\rm d). One particular electron
radiation environment, relative to a geosynchronous earth orbit (GEO),
is chosen to calculate the total D_\rm d behind the different
thicknesses coverglasses to predict the performance degradation at
the end of the 15-year mission.

A ZnO nanowire (NW) field-effect transistor (FET) is
fabricated and characterized, and its characterization of
ultraviolet radiation is also investigated. On the one hand, when
the radiation time is 5~min, the radiation intensity increases
to 5.1~μ W/cm^{2}, while the saturation drain current (I_\rm
dss) of the nanowire FET decreases sharply from 560 to 320~nA. The
field effect mobility (μ ) of the ZnO nanowire FET drops from
50.17 to 23.82~cm^{2}/(V.s) at V_\rm DS=2.5~V, and
the channel resistivity of the FET increases by a factor of 2. On
the other hand, when the radiation intensity is 2.5~μ W/cm^2
, the DC performance of the FET does not change significantly with
irradiation time (its performances at irradiation times of 5 and
20~min are almost the same); in particular, the I_\rm dss of NW FET
only reduces by about 50~nA. Research is underway to reveal the intrinsic
properties of suspended ZnO nanowires and to explore their device
applications.

ZnO nanopowder is successfully synthesized by annealing
the precursors in oxygen gas using the chemical precipitation method.
Structural and optical properties of thus synthesized ZnO nanopowder
are characterized by scanning electron microscopy (SEM) and
photoluminescence (PL). The morphology of ZnO nanopowders evolves
from nanorod to cobble as annealing temperature increases from 500
to 1000~\du, while spiral structures are observed in the samples
annealed at 900 and 1000~\du. The PL spectra of ZnO nanopowder
consist of largely green and yellow emission bands. The green
emission from ZnO nanopowder depends strongly on the annealing
temperature with a peak intensity at a temperature lower than 800~℃
while the yellow emission is associated with interstitial oxygen
\rm O_\i.

Fundamentals of the Schottky contacts and the
high-temperature current conduction through three kinds of Schottky
diodes are studied. N-Si Schottky diodes, GaN Schottky diodes and
AlGaN/GaN Schottky diodes are investigated by I--V--T
measurements ranging from 300 to 523~K. For these Schottky diodes, a
rise in temperature is accompanied with an increase in barrier
height and a reduction in ideality factor. Mechanisms are
suggested, including thermionic emission, field emission,
trap-assisted tunnelling and so on. The most remarkable finding in
the present paper is that these three kinds of Schottky diodes are
revealed to have different behaviours of high-temperature reverse
currents. For the n-Si Schottky diode, a rise in temperature is
accompanied by an increase in reverse current. The reverse current
of the GaN Schottky diode decreases first and then increases with
rising temperature. The AlGaN/GaN Schottky diode has a trend
opposite to that of the GaN Schottky diode, and the dominant
mechanisms are the effects of the piezoelectric polarization field and
variation of two-dimensional electron gas charge density.

The effect of Fe-doping on the magnetic properties of the
ABO_{3}-type perovskite cobaltites La_{0.7}Ba_{0.3}Co_1 -
yFe_yO_{3} (0 ≤ y ≤ 0.80) is reported. With no
apparent structural change in any doped sample, the Curie
temperature (T_{C}) and the magnetization (M) are greatly
suppressed for y ≤ 0.30 samples, while a distinct increase in
T_{C} for the y=0.40 sample is observed. With the further
increase of Fe concentration, T_{C} increases monotonically.
Griffiths-like phases in 0.40 ≤ y ≤ 0.60 samples are
confirmed. The formation of the Griffiths-like phase is ascribed to
B-site disordering induced isolation of ferromagnetic (FM)
clusters above T_{C}.

The temperature effect on tunnelling splitting in the
spin--boson model with a super-ohmic bath is studied by the small
polaron theory. The coherent--incoherent transition temperature is
calculated and its dependence on dissipation strength and bare
tunnelling splitting is analysed. In additional to the traditional
transition point described in textbooks, a new kind of transition
is found in the low dissipation region, showing different
temperature dependence in the transition. The relation to the
corresponding transition in the polaron--phonon system is also
discussed.

Nb/Al-AlO_{x}/Nb tunnel junctions with controllable
critical current density J_{c} are fabricated using the
standard selective Nb etching process. Tunnel barriers are formed in
different oxygen exposure conditions (oxygen pressure P and
oxidation time t), giving rise to J_{c} ranging from
100~A/cm^{2} to above 2000 A/cm^{2}. J_{c} shows a familiar
linear dependence on P×t in logarithmic scales. We calculate
the energy levels of the phase- and flux-type qubits using the
achievable junction parameters and show that the fabricated
Nb/Al-AlO_{x}/Nb tunnel junctions can be used conveniently for
quantum computation applications in the future.

We study (Ga, Mn)As diluted magnetic semiconductors in
terms of the Ruderman--Kittel--Kasuya--Yosida quantum spin model in
Green's function approach. Random distributions of the magnetic
atoms are treated by using an analytical average of magnetic
configurations. Average magnetic moments and spin excitation spectra
as functions of temperature can be obtained by solving
self-consistent equations, and the Curie temperature T_{C} is
given explicitly. T_{C} is proportional to magnetic atomic
concentration, and there exists a maximum for T_{C} as a
function of carrier concentration. Applied to (Ga, Mn)As, the
theoretical results are consistent with experiment and the
experimental T_{C} can be obtained with reasonable parameters.
This modelling can also be applied to other diluted magnetic
semiconductors.

β-Mn_{2}V_{2}O_7 crystals with strip
shape are successfully prepared by the molten salt method in a closed
crucible, and are characterized by x-ray diffraction (XRD),
scanning electron microscopy (SEM), transmission electron microscopy
(TEM), selected area of electron diffraction (SAED) and
high-resolution transmission electron microscopy (HRTEM). The
results indicate that the sample is of the β
-Mn_{2}V_{2}O_{7} crystal with monoclinic symmetry, level
natural cleavage facets and directional growth. Magnetic properties
are measured by vibration sample magnetometry (VSM) at room
temperature, and the magnetic hysteresis loop indicates that the
β-Mn_{2}V_{2}O_{7} has anti-ferromagnetic properties
with low coercive force and remnant magnetization. The magnetic
measurement results in different directions exhibit that the β
-Mn_{2}V_{2}O_{7} has magnetic anisotropy, which is due to
the fact that the magnetic interaction energy of the β
-Mn_{2}V_{2}O_{7} is lowest only when the electron configuration
is in a certain direction.

Simulations are performed on clusters of finite size to
study the effects of size and current-path structure on
magnetotransport in spatially-confined samples. Magnetotransport
networks are established and calculated based on fractal structures
including Koch curves and percolation backbones extracted from
regular lattices. The structure pattern of clusters is shown to play
an important role in the magnetotransport behaviours by affecting
the magnetoresistance fluctuations due to spin disorder in the
systems of small size, which suggests the possibility of controlling
the magnetotransport by the design of current-path
configurations.

Hole-net structure silicon is fabricated by laser
irradiation and annealing, on which a photoluminescence (PL) band in a
the region of 650--750~nm is pinned and its intensity increases
obviously after oxidation. It is found that the PL intensity changes
with both laser irradiation time and annealing time. Calculations
show that some localized states appear in the band gap of the
smaller nanocrystal when Si=O bonds or Si--O--Si bonds are
passivated on the surface. It is discovered that the density and the
number of Si=O bonds or Si--O--Si bonds related to both the
irradiation time and the annealing time obviously affect the
generation of the localized gap states of hole-net silicon, by which
the production of stimulated emission through controlling oxidation
time can be explained.

8000 CROSSDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY

This paper addresses the problem of estimating lower
atmospheric refractivity under the nonstandard propagation conditions
frequently encountered in low altitude maritime radar applications.
The vertical structure of the refractive environment is modeled by
using a five-parameter model, and the horizontal structure is modeled
as range-independent. The electromagnetic propagation in the
troposphere is simulated by using a split-step fast Fourier
transform based on parabolic approximation to the wave equation. A
global search marked as a modified genetic algorithm (MGA) for the 5
environmental parameters is performed by using a genetic algorithm
(GA) integrated with a simulated annealing technique. The retrieved
results from simulated runs demonstrate the ability of this method
to make atmospheric refractivity estimations. A comparison with the classical GA
and the Bayesian Markov Chain Monte Carlo (Bayesian-MCMC) technique
shows that the MGA can not only shorten the inverse time but also
improve the inverse precision. For real data cases, the inversion
values do not match the reference data very well. The
inverted profile, however, can be used to synoptically describe
the real refractive structure.

Complex networks have been studied across many fields of science
in recent years. In this paper, we give a brief introduction of
networks, then follow the original works by Tsonis et al
(2004, 2006) starting with data of the surface temperature from 160
Chinese weather observations to investigate the topology of
Chinese climate networks. Results show that the Chinese climate network
exhibits a characteristic of regular, almost fully connected
networks, which means that most nodes in this case have the same number
of links, and so-called super nodes with a very large number of
links do not exist there. In other words, though former results show
that nodes in the extratropical region provide a property of
scale-free networks, they still have other different local fine
structures inside. We also detect the community of the Chinese
climate network by using a Bayesian technique; the effective number
of communities of the Chinese climate network is about four in this
network. More importantly, this technique approaches results in
divisions which have connections with physics and dynamics; the
division into communities may highlight the aspects of the dynamics
of climate variability.

[an error occurred while processing this directive]