This paper obtains the multi-component
Harry--Dym (H--D) hierarchy and its integrable couplings by
using two kinds of vector loop algebras \widetilde{G}_{3} and \widetilde{G}_{6}.
The Hamiltonian structures of the above system are
given by the quadratic-form identity. The method can be used
to produce the Hamiltonian structures of the other
integrable couplings or multi-component hierarchies.

This paper derives new discrete integrable system based on discrete
isospectral problem. It shows that the hierarchy is completely
integrable in the Liouville sense and possesses bi-Hamiltonian
structure. Finally, integrable couplings of the obtained system is
given by means of semi-direct sums of Lie algebras.

This paper discusses the conformal invariance by infinitesimal
transformations of canonical Hamilton systems. The necessary and
sufficient conditions of conformal invariance being Lie symmetrical
simultaneously by the action of infinitesimal transformations are
given. The determining equations of the conformal invariance are
gained. Then the Hojman conserved quantities of conformal invariance
by special infinitesimal transformations are obtained. Finally an
illustrative example is given to verify the results.

Asymptotic solutions up to third-order which describe irrotational
finite amplitude standing waves are derived in Lagrangian
coordinates. The analytical Lagrangian solution that is uniformly
valid for large times satisfies the irrotational condition and the
pressure p=0 at the free surface, which is in contrast with the
Eulerian solution existing under a residual pressure at the free
surface due to Taylor's series expansion. In the third-order
Lagrangian approximation, the explicit parametric equation and the
Lagrangian wave frequency of water particles could be obtained. In
particular, the Lagrangian mean level of a particle motion that is a
function of vertical label is found as a part of the solution which
is different from that in an Eulerian description. The dynamic
properties of nonlinear standing waves in water of a finite depth,
including particle trajectory, surface profile and wave pressure are
investigated. It is also shown that the Lagrangian solution is
superior to an Eulerian solution of the same order for describing
the wave shape and the kinematics above the mean water level.

Spatiotemporal multiple coherence resonances for calcium activities
induced by weak Gaussian white noise in coupled hepatocytes are
studied. It is shown that bi-resonances in hepatocytes are induced
by the interplay and competition between noise and coupling of
cells, in other words, the cell in network can be excited either by
noise or by its neighbour via gap junction which can transfer
calcium ions between cells. Furthermore, the intercellular annular
calcium waves induced by noise are observed, in which the wave
length decreases with noise intensity augmenting but increases
monotonically with coupling strength increasing. And for a fixed
noise level, there is an optimal coupling strength that makes the
coherence resonance reach maximum.

This paper presents a detailed analysis of the dependence of
degree of strain relaxation of the self-organized InAs/GaAs quantum
dot on the geometrical parameters. Differently shaped quantum dots
arranged with different transverse periods are simulated in this
analysis. It investigates the total residual strain energy that
stored in the quantum dot and the substrate for all kinds of quantum
dots with the same volume, as well as the dependence on both the
aspect ratio and transverse period. The calculated results show that
when the transverse period is larger than two times the base of the
quantum dots, the influence of transverse periods can be ignored.
The larger aspect ratio will lead more efficient strain relaxation.
The larger angle between the faces and the substrate will lead more
efficient strain relaxation. The obtained results can help to
understand the shape transition mechanism during the epitaxial
growth from the viewpoint of energy, because the strain relaxation
is the main driving force of the quantum dot's self-organization.

The influences of dipole--dipole interaction and detuning on the
entanglement between two atoms with different initial tripartite
entangled W-like states in the Tavis--Cummings model have been
investigated by means of Wootters' concurrence, respectively. The
results show that the entanglement between the two atoms can be
enhanced via appropriately tuning the strength of dipole--dipole
interaction of two atoms or the detunings between atom and cavity,
and the so-called sudden death effect can be weakened
simultaneously.

In this paper, we propose a scheme for implementing quantum game
(QG) in cavity quantum electrodynamics(QED). In the scheme, the
cavity is only virtually excited and thus the proposal is
insensitive to the cavity fields states and cavity decay. So our
proposal can be experimentally realized in the range of current
cavity QED techniques.

Recent years, several ways of implementing quantum games in different physical systems
have been presented. In this paper, we perform a theoretical analysis of an experimentally feasible
way to implement a two player
quantum game in cavity quantum electrodynamic(QED). In the scheme,
the atoms interact simultaneously with a highly detuned cavity mode
with the assistance of a classical field. So the scheme is
insensitive to the influence from the cavity decay and the thermal
field, and it does not require the cavity to remain in the vacuum
state throughout the procedure.

Based on thermo field dynamics (TFD) and using the thermo Wigner
operator in the thermo entangled state representation we derive the
Wigner function of number states at finite temperature (named thermo
number states). The figure of Wigner function shows that its shape
gets smoothed as the temperature rises, implying that the quantum
noise becomes larger.

This paper proposes a simple scheme for realizing one-qubit and
two-qubit quantum gates as well as multiqubit entanglement based on
dc-SQUID charge qubits through the control of their coupling to a 1D
transmission line resonator (TLR). The TLR behaves effectively as a
quantum data-bus mode of a harmonic oscillator, which has several
practical advantages including strong coupling strength,
reproducibility, immunity to 1/f noise, and suppressed spontaneous
emission. In this protocol, the data-bus does not need to stay
adiabatically in its ground state, which results in not only fast
quantum operation, but also high-fidelity quantum information
processing. Also, it elaborates the transfer process with the 1D
transmission line.

The analysis is based on the error rate and the secure communication
rate as functions of distance for three quantum-key-distribution
(QKD) protocols: the Bennett--Brassard 1984, the
Bennett--Brassard--Mermin 1992, and the coherent
differential-phase-shift keying (DPSK) protocols. We consider the
secure communication rate of the DPSK protocol against an arbitrary
individual attack, including the most commonly considered
intercept-resend and photon-number splitting attacks, and concluded
that the simple and efficient differential-phase-shift-keying
protocol allows for more than 200 km of secure communication
distance with high communication rates.

By virtue of the well-behaved properties of the bipartite entangled
states representation, this paper analyse and solves some master
equations for generalized phase diffusion models, which seems
concise and effective. This method can also be applied to solve
other master equations.

This paper discusses the basic categories of noise in detecting high
frequency gravitational waves in the microwave band (～0.1--10 GHz), which contain shot noise from the laser and the
thermal radiation photons, thermal noise from statistical
fluctuation of the thermal photons and fluctuation of the
temperature, radiation press noise on the fractal membrane, the
noise caused by the scattering of the Gaussian Beam (GB) in the
detecting tube and noise in the microwave radiometers. The analysis
shows that a reasonable signal-to-noise ratio may be achieved for a
detecting device with the fixed power of GB (10^{5} W), only when
the temperature of the environment is no more than T=1 K, and the
optimal length of the microwave radiometers is about 0.3 m.

A Carnot cycle outside a Schwarzschild black hole is investigated in
detail. We propose a reversible Carnot cycle with a black hole being
the cold reservoir. In our model, a Carnot engine operates between a
hot reservoir with temperature T_{1} and a black hole with Hawking
temperature T_{H}. By naturally extending the ordinary Carnot
cycle to the black hole system, we show that the thermal efficiency
for a reversible process can reach the maximal efficiency 1-T_{H}/T_{1}. Consequently, black holes can be used to
determine the thermodynamic temperature by means of the Carnot cycle.
The role of the atmosphere around the black hole is discussed. We
show that the thermal atmosphere provides a necessary mechanism to
make the process reversible.

Many realistic networks have community structures, namely, a network
consists of groups of nodes within which links are dense but among
which links are sparse. This paper proposes a growing network model
based on local processes, the addition of new nodes intra-community
and new links intra- or inter-community. Also, it utilizes the
preferential attachment for building connections determined by
nodes' strengths, which evolves dynamically during the growth of the
system. The resulting network reflects the intrinsic community
structure with generalized power-law distributions of nodes' degrees
and strengths.

By developing multiple-scale method combined with
Wentzel--Kramer--Brillouin expansion, this paper analytically
studies the modulating effect of weakly periodic potential on the
dynamical properties of the Bose--Einstein condensates (BEC) trapped
in harmonic magnetic traps. A black--grey soliton transition is
observed in the BEC trapped in harmonic magnetic potential, due to
the weakly periodic potential modulating effect. Meanwhile, it finds
that with the slight increase of the weakly periodic potential
strength, the velocity of the soliton decreases, while its width
firstly decreases then increases, a minimum exists there. These
results show that the amplitude, velocity, and width of matter
solitons can be effectively managed by means of a weakly periodic
potential.

Stochastic resonance (SR) of a periodically driven time-delayed
linear system with multiplicative white noise and periodically
modulated additive white noise is investigated. In the condition of
small delay time, an approximate analytical expression of output
signal-to-noise ratio (SNR) is obtained. The analytical results
indicate that (1) there exists a resonance peak in the curve for
SNR versus time delay; (2) the time delay will suspend the SR
dramatically for SNR versus other parameters of the system, such as
noise intensity, correlation intensity, and signal frequency, once a
certain value is reached, the SR phenomenon disappears.

By adding frequency modulated signals to the intensity equation of
gain--noise model of the single-mode laser driven by two coloured
noises which are correlated, this paper uses the linear
approximation method to calculate the power spectrum and
signal-to-noise ratio (SNR) of the laser intensity. The results show
that the SNR appears typical stochastic resonance with the variation
of intensity of the pump noise and quantum noise. As the amplitude
of a modulated signal has effects on the SNR, it shows suppression,
monotone increasing, stochastic resonance, and multiple stochastic
resonance with the variation of the frequency of a carrier signal
and modulated signal.

Nonlinear response of the driven Duffing oscillator to periodic or
quasi-periodic signals has been well studied. In this paper, we
investigate the nonlinear response of the driven Duffing oscillator
to non-periodic, more specifically, chaotic time series. Through
numerical simulations, we find that the driven Duffing oscillator
can also show regular nonlinear response to the chaotic time series
with different degree of chaos as generated by the same chaotic
series generating model, and there exists a relationship between the
state of the driven Duffing oscillator and the chaoticity of the
input signal of the driven Duffing oscillator. One real-world and
two artificial chaotic time series are used to verify the new
feature of Duffing oscillator. A potential application of the new
feature of Duffing oscillator is also indicated.

A scheme for the impulsive control of nonlinear systems with
time-varying delays is investigated in this paper. Based on the
Lyapunov-like stability theorem for impulsive functional
differential equations (FDEs), some sufficient conditions are
presented to guarantee the uniform asymptotic stability of
impulsively controlled nonlinear systems with time-varying delays.
These conditions are more effective and less conservative than those
obtained. Finally, two numerical examples are provided to
demonstrate the effectiveness of the proposed method.

In this paper, we present a new car-following model by taking into
account the effects of the traffic interruption probability on the
car-following behaviour of the following vehicle. The stability
condition of the model is obtained by using the linear stability
theory. The modified Korteweg--de Vries (KdV) equation is constructed
and solved, and three types of traffic flows in the
headway sensitivity space---stable, metastable, and unstable---are
classified. Both the analytical and simulation results show that the
traffic interruption probability indeed has an influence on driving
behaviour, and the consideration of traffic interruption probability
in the car-following model could stabilize traffic flow.

This paper establishes the energy selective electron (ESE) engine
with double resonances as a refrigerator in one dimensional (1D)
system. It consists of two infinitely large electron reservoirs with
different temperatures and chemical potentials, and they are
perfectly thermally insulated from each other and interaction only
via a double `idealized energy filter' whose widths are all finite.
Taking advantage of the density of state and Fermi distribution in the 1D
system, the heat flux into each reservoir may then be calculated.
Moreover, the coefficient of performance may be derived from the
expressions for the heat flux into the hot and cold reservoirs. The
performance characteristic curves are plotted by numerical analysis.
The influences of the resonances widths, the energy position of
resonance and the space of two resonances on performance of the ESE
refrigerator are discussed. The results obtained here have
theoretical significance for the understanding of thermodynamic
performance of the micro--nano devices.

This paper studies the cascading failure on random networks and
scale-free networks by introducing the tolerance parameter of edge
based on the coupled map lattices methods. The whole work focuses on
investigating some indices including the number of failed edges,
dynamic edge tolerance capacity and the perturbation of edge. In
general, it assumes that the perturbation is attributed to the
normal distribution in adopted simulations. By investigating the
effectiveness of edge tolerance in scale-free and random networks,
it finds that the larger tolerance parameter λ can more
efficiently delay the cascading failure process for scale-free
networks than random networks. These results indicate that the
cascading failure process can be effectively controlled by
increasing the tolerance parameter λ. Moreover, the
simulations also show that, larger variance of perturbation can
easily trigger the cascading failures than the smaller one. This
study may be useful for evaluating efficiency of whole traffic
systems, and for alleviating cascading failure in such systems.

This paper illuminates the preparation of grating-like polystyrene
latex monolayer structure, which can minimize the effects of the
size deviation of spheres and the defect transfer on the accuracy as
calibration samples for microscopes. The latex films are grown on
freshly cleaved mica substrates by vertical deposition method. The
concentration dependence of the structure and the topography of
latex films is characterized by optical microscope,
ultraviolet--visible transmission spectrum and scanning probe
microscope. The origination of such a grating-like structure is also
discussed.

By using topological current theory, this paper studies the inner
topological structure of disclinations during the melting of
two-dimensional systems. From two-dimensional elasticity theory, it
finds that there are topological currents for topological defects in
homogeneous equation. The evolution of disclinations is studied, and
the branch conditions for generating, annihilating, crossing,
splitting and merging of disclinations are given.

The Ho:YAP crystal is grown by the Czochralski technique. The
room-temperature polarized absorption spectra of Ho:YAP crystal was
measured on a c-cut sample with 1 at% holmium. According to the
obtained Judd--Ofelt intensity parameters
Ω_{2}=1.42× 10^{20} cm^{2},
Ω_{4}=2.92× 10^{20} cm^{2}, and Ω_{6}=1.71× 10^{20} cm^{2}, this paper calculated the
fluorescence lifetime to be 6 ms for ^{5}I_{7}→^{5}I_{8}
transition, and the integrated emission cross section to be
2.24× 10^{-18} cm^{2}. It investigates the
room-temperature Ho:YAP laser end-pumped by a 1.91-μm Tm:YLF
laser. The maximum output power was 4.1 W when the incident
1.91-μm pump power was 14.4 W. The slope efficiency is
40.8%, corresponding to an optical-to-optical conversion
efficiency of 28.4%. The Ho:YAP output wavelength was centred at
2118 nm with full width at half maximum of about 0.8 nm.

The asymmetric photoionization of atoms irradiated by intense,
few-cycle laser pulses is studied numerically. The results show that
the pulse intensity affects the asymmetric photoionization in three
aspects. First, at higher intensities, the asymmetry becomes
distinctive for few-cycle pulses of longer durations. Second, as the
laser intensity increases, the maximal asymmetry first decreases
then increases after it has reached a minimal value. Last, the value
of the carrier-envelope phase corresponding to the maximal asymmetry
varies with the pulse intensity. This study reveals that the
increasing of pulse intensity is helpful for observing the
asymmetric photoionization.

The elastic scattering properties of ultracold ^{133}Cs_{2}
triplet state are investigated in detail. We construct a potential
curve of the ^{133}Cs_{2} triplet state, based on the latest ab initio
molecular potential data and show how the scattering
parameters are obtained by using three methods: the Numerov method,
the semiclassical method and the variable phase method, where the
scattering lengths of the ^{133}Cs_{2} triplet state, i.e.
301.79a_{0}, 300.67a_{0} and 310.81a_{0} are obtained respectively,
with a_{0} being the Bohr radius. We also calculate the effective
range and the number of bound states for the ^{133}Cs_{2} triplet
state. Our results are in agreement with the recent experimental
data and the theoretical calculations. This confirms that the
results of the scattering properties of the ultracold ^{133}Cs_{2}
triplet state, calculated by using these three methods, are
reliable.

By using coordinate transformation method, this paper obtains an
useful equation of designing meta-material cloaks embedded in
anisotropic medium. This equation is the generalization of what was
introduced early by Pendry et al (2006 \textit{Science}
{312 1780) and can be more widely used. As an example of its
applications, this paper deduces the material parameter equation for
cylinder cloaks embedded in anisotropic medium, and then offers the
numerical simulation. The results show that such a cylinder cloak
has perfect cloaking performance and therefore verifies the method
proposed in this paper.

Metallic gratings with narrow slits can lead to special optical
properties such as strongly enhancing the transmission and
considerably strengthening the polarized effect. A narrow-band
filter suitable for application in optical communication is
designed by sandwiching a metallic grating between two identical
dielectric films. The maximum transmission can reach 96% after
optimizing the parameters of films and grating at a central
wavelength of 1053 nm. It is the first time, to our knowledge, that
such high transmission has been reported since the discovery of
the extraordinarily high transmission through periodic holes or
slits; moreover, the extremely polarized effect is also found in P
mode of this symmetric grating.

This paper studies the propagation properties of Gauss--Bessel beams
in a turbulent atmosphere. Based on the extended Huygens--Fresnel
principle, it derives the intensity distribution expression for such
beams propagating in a turbulent atmosphere. Then the influence of
turbulence and source beam parameters on the beam propagation is
studied in great detail. It finds that the intensity distribution of
Gauss--Bessel beams will change into Gaussian profile in a turbulent
atmosphere, and that stronger turbulence and smaller topological
charges will lead to a faster changing.

This paper calculates light scattering by a spherical water particle
containing densely packed inclusions at a visible wavelength
0.55 \mum by a combination of ray-tracing and Monte Carlo
techniques. While the individual reflection and refraction events at
the outer boundary of a sphere particle are considered by a
ray-tracing program, the Monte Carlo routine simulates internal
scattering processes. The main advantage of this method is that the
shape of the particle can be arbitrary, and multiple scattering can
be considered in the internal scattering processes. A dense-medium
light-scattering theory based on the introduction of the static
structure factor is used to calculate the phase function and
asymmetry parameters for densely packed inclusions. Numerical
results of the single scattering characteristics for a sphere
containing multiple densely packed inclusions are given.

This paper proposes an efficient scheme for deterministic generation
of entangled coherent states for two atomic samples. In the scheme
two collections of atoms are trapped in an optical cavity and driven
by a classical field. Under certain conditions the two atomic
samples evolve from an coherent state to an entangled coherent
state. During the interaction the cavity mode is always in the
vacuum state and the atoms have no probability of being populated in
the excited state. Thus, the scheme is insensitive to both the
cavity decay and atomic spontaneous emission.

The fidelity of the generated Schr?dinger Cat state (SCS) of a
single trapped ion in the Lamb--Dicke approximation is discussed.
The results show that the fidelity significantly decreases with the
values of Lamb--Dicke parameter η and coherent state amplitude
α increasing. For η= 0.20 and α= 3, the
typical values of experimental parameters, the fidelity is rather
low (30%). A scheme for generating the SCS is proposed without
making the Lamb--Dike approximation in laser--ion interaction, and
the fidelity of the generated SCS is about 99% for the typical
values of experimental Lamb--Dicke parameters.

In an open ladder-type resonant atomic system, variation in relative
phase between probe and driving fields does not affect the transient
evolution of populations, but it has remarkable effects on gain and
dispersion of the probe field. No matter whether an incoherent pump
is present or absent, transient and stationary gains without
inversion (GWI) always can be obtained by choosing an appropriate
value of the relative phase. When the incoherent pump is absent，the
values of transient and stationary GWIs are much larger and the time
interval required to reach the stationary value is longer than those
when the incoherent pump is present. Varying the exit rate and the
ratio between injection rates can obviously change the
phase-dependent GWI. In addition, in the transient evolution
process, the phenomenon of high dispersion (refractive index)
without absorption occurs at some values of relative phase. In the
corresponding closed system, the stationary GWI can be obtained by
choosing an appropriate value of relative phase only when incoherent
pump exists, moreover the gain is smaller than that in the open
system.

By introducing the two-mode entangled state representation
<η| whose one mode is a fictitious one
accompanying the system mode, this paper presents a new approach for
deriving density operator for describing continuum photodetection
process.

We introduce a new kind of four-mode continuous variable entangled
state in Fock space. The completeness relation and the partly
nonorthonormal property of such a state are proven. The scheme to
generate this state is presented by combining a symmetrical
beamsplitter, a parametric down-conversion and a polarizer. After
making a single-mode quadrature amplitude measurement, the remaining
three modes are kept in entanglement. And its applications are also
discussed.

Under a nonresonant condition, we theoretically investigate hybrid
absorptive-dispersive optical bistability and multistability
behaviours in a three-level Δ-type system by using a microwave
field to drive a hyperfine transition between two upper excited
states inside a unidirectional ring cavity. We find that the optical
bistability and multistability behaviours can be controlled by
adjusting the intensity of the microwave field or the intensity of
the coherent coupling field. Furthermore, our studies show an
interesting phenomenon of the transition from the optical
bistability to the optical multistability only by changing the
negative detuning of the coupling field into the positive detuning
of the coupling field.

A diode-end-pumped Nd:YAG dual-wavelength laser operating at 1319
and 1338 nm is demonstrated. The maximum average output power of
the quasi-continuous wave linearly polarized dual-wavelength laser
is obtained to be 2.1 W at a repetition rate of 50 kHz with an
output power instability of less than 0.38% and beam quality
factor M^{2} of 1.45. Using the two lines, the highly coherent and
narrow linewidth terahertz radiation of 3.23 THz can be generated
in an organic 4-N, N-dimethylamino--methyl-stilbazolium tosylate
(DAST) crystal. Meanwhile, the multi-wavelength red laser at 659.5,
664 and 669 nm is generated by frequency doubling and sum frequency
processes in a lithium triborate (LBO) crystal. The average red
laser output power is enhanced up to 1.625 W at a repetition rate
of 15 kHz with an output power instability of better than 0.53%
and beam quality factor M^{2} of 6.05. Using the three lines, it
is possible to generate the multi-wavelength THz radiation of 3.3,
3.43 and 6.73 THz in an appropriate difference frequency crystal.

The terahertz (THz) spectrum absorptions of nematic liquid crystal
(LC) material, i.e. N-(p-methoxybenzylidene)-p-butylaniline (MBBA),
and its relevant compounds are simulated in this paper by using the
density functional theory (DFT) method. A strong absorptive
frequency is located at 3.65 THz for the MBBA, which is in
agreement with experimental data found in the literature. The result
suggests that the DFT method is effective for dealing with the
anisotropic nematic LC compounds.

One of the important characteristic of adaptive mirrors is the
thermal stability of surface flatness. In this paper, the thermal
stability from 13℃ to 25℃ of a 20-actuator
bimorph deformable mirror is tested by a Shack--Hartmann wavefront
sensor. Experimental results show that, the surface P--V of bimorph
increases nearly linearly with ambient temperature. The ratio is
0.11μm/℃ and the major component of surface
displacement is defocused, compared with which, astigmatism, coma
and spherical aberration contribute very small. Besides, a finite
element model is built up to analyse the influence of thickness,
thermal expansion coefficient and Young's modulus of materials on
thermal stability. Calculated results show that bimorph has the best
thermal stability when the materials have the same thermal expansion
coefficient. And when the thickness ratio of glass to PZT is 3 and
Young's modulus ratio is approximately 0.4, the surface instability
behaviour of the bimorph manifests itself most severely.

A general numerical tool, based on thermal diffusion equation and
full-vectorial eigen-mode equation, has been presented for the
systematic analysis of graded index channel waveguide fabricated by
ion exchange on Er^{3+} doped glass. Finite difference method
with full-vectorial formulation (FV-FDM) is applied to solving the
full-vectorial modes of graded index channel waveguide for the first
time. The coupled difference equations based on magnetic fields in
FV-FDM are derived from the Taylor series expansion and accurate
formulation of boundary conditions. Hybrid nature of vectorial
guided modes for both pump (980 nm) and signal light (1550 nm) are
demonstrated by the simulation. Results show that the fabrication
parameters of ion exchange, such as channel opening width and time
ratio of second step to first step in ion exchange, have large
influence on the properties of waveguide. By optimizing the
fabrication parameters, maintenance of monomode for signal light and
improvement of the gain dynamics can be achieved in Er^{3+}
doped waveguide amplifier (EDWA) fabricated by ion exchange
technique. This theoretical model is significant for the design and
fabrication of EDWA with ion exchange technique. Furthermore, a
single polarization EDWA, which operates at wavelength from 1528 nm
to 1541 nm for HE polarization, is numerically designed.

This paper presents a Kerr-lens mode-locked Ti:sapphire laser at the
repetition rate of 525 MHz, stable laser pulse as short as 10 fs
with average output power of 480 mW is obtained. By injecting the
pulse into photonics crystal fibre, octave-spanning spectrum covered
from 500 to 1050 nm is generated, carrier-envelope phase frequency
with signal-to-noise ratio of 31dB is measured, which paves the way
for the generation of a compact frequency comb.

Using the finite element method, this paper investigates lateral
stress-induced propagation characteristics in a photonic crystal
fibre of hexagonal symmetry. The results of simulation show the
strong stress dependence of effective index of the fundamental
guided mode, phase modal birefringence and confinement loss. It also
finds that the contribution of the geometrical effect that is
related only to deformation of the photonic crystal fibre and the
stress-related contribution to phase modal birefringence and
confinement loss are entirely different. Furthermore,
polarization-dependent stress sensitivity of confinement loss is
proposed in this paper.

This paper investigates the zero dispersion wavelength and
dispersion slope control of hollow-core photonic bandgap fibres
(PBGFs) by using a full-vector finite element method. By simulation
we found that theoretically the zero dispersion wavelength can be
tailored by respectively changing the rounded diameter of air holes,
pitch, refractive index, normalized thickness of core rings, and
hole diameter to pitch ratio. At the same time the tailoring of
dispersion slope can also be realized by changing the rounded diameter
of air holes or pitch or normalized thickness of core rings. To
illustrate the reasonability of fibre designs, this paper also gives
the variance of normalized interface field intensity which measures
the scattering loss relatively versus wavelength for different
designs. From the viewpoint of loss, varying the rounded diameter
and the thickness of core ring could shift zero wavelength but it is
difficult to get the required parameters within so tiny range in
practical drawing of PBGFs, on the other hand, it is possible in
practice to respectively alter the pitch and refractive index to
shift zero wavelength. But varying hole diameter to pitch ratio is
not worthwhile because they each induce large increase of loss and
narrowness of transmission bandwidth. The zero dispersion wavelength
can be engineered by respectively varying the rounded diameter of air
holes, pitch, refractive index, and normalized thickness of core
rings without incurring large loss penalties.

By making a comparison between the acoustic equations and the
2-dimensional (2D) Maxwell equations, we obtain the material
parameter equations (MPE) for acoustic elliptical cylindrical
cloaks. Both the theoretical results and the numerical results
indicate that an elliptical cylindrical cloak can realize perfect
acoustic invisibility when the spatial distributions of mass density
and bulk modulus are exactly configured according to the proposed
equations. The present work is the meaningful exploration of
designing acoustic cloaks that are neither sphere nor circular
cylinder in shape, and opens up possibilities for making complex and
multiplex acoustic cloaks with simple models such as spheres,
circular or elliptic cylinders.

Based on multi-fluid volume fraction and piecewise parabolic method
(PPM), a multi-viscosity-fluid hydrodynamic code MVPPM
(Multi-Viscosity-Fluid Piecewise Parabolic Method) is developed and
applied to the problems of shock-induced hydrodynamic interfacial
instability and mixing. Simulations of gas/liquid interface
instability show that the influences of initial perturbations on the
fluid mixing zone (FMZ) growth are significant, especially at the
late stages, while grids have only a slight effect on the FMZ width,
when the interface is impulsively accelerated by a shock wave
passing through it. A numerical study of the hydrodynamic
interfacial instability and mixing of gaseous flows impacted by
re-shocks is presented. It reveals that the numerical results are in
good agreement with the experimental results and the mixing growth
rate strongly depends on initial conditions. Ultimately, the jelly
layer experiment relevant to the instability impacted by exploding
is simulated. The shape of jelly interface, position of front face
of jelly layer, crest and trough of perturbation versus time are
given; their simulated results are in good agreement with
experimental results.

PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES

This paper demonstrates the triggering and guiding of the stationary
high voltage (HV) discharges at 5--40 kV by using plasma filaments
generated by femtosecond laser pulses in air. A significant
reduction of the breakdown voltage threshold due to the
pre-ionization of the air gap by laser filamentation is observed.
The discharge experiments are performed by using laser pulses with
different energy from 15--60 mJ. The electron density of filaments
is detected by sonography method. The influence of the electron
density of laser filaments on the triggering and guiding HV
discharge is experimentally investigated. The results have shown
that the behaviour of plasma filaments can strongly affect the
efficiency of triggering and guiding HV discharge.

This paper presents the anisotropic optical feedback of a single
frequency intra-cavity He--Ne laser. A novel phenomenon was
discovered that the laser output an elliptical polarized frequency
instead of the initial linear polarized one. Two intensities with a
phase difference were detected, both of which were modulated in the
form of cosine wave and a fringe shift corresponds to a λ/2
movement of the feedback mirror. The phase difference can be
continuously modulated by the wave plate in the external cavity.
Frequency stabilization was used to stabilize the laser frequency so
as to enlarge the measuring range and improve the measurement
precision. This anisotropic optical feedback system offers a
potential displacement measurement technology with the function of
subdivision of λ/2 and in-time direction judgment.
The three-mirror Fabry--Perot cavity model is used to present the
experimental results. Given the lack of need of lasing adjustment,
this full intra-cavity laser can significantly improve the
simplicity and stability of the optical feedback system.

The propagation of the fast muon population mainly due to
collisional effect in a dense deuterium--tritium (DT for short)
mixture is investigated and analysed within the framework of the
relativistic Fokker--Planck equation. Without the approximation that
the muons propagate straightly in the DT mixture, the muon
penetration length, the straggling length, and the mean transverse
dispersion radius are calculated for different initial energies, and
especially for different densities of the densely compressed DT
mixture in our suggested muon-driven fast ignition (FI). Unlike
laser-driven FI requiring super-high temperature, muons can catalyze
DT fusion at lower temperatures and may generate an ignition sparkle
before the self-heating fusion follows. Our calculation is important
for the feasibility and the experimental study of muon-driven FI.

Xu Xiao-Yuan, Wang Jun, Yu Yi, Wen Yi-Zhi, Yu Chang-Xuan, Liu Wan-Dong, Wan Bao-Nian, Gao Xiang, N. C. Luhmann, C. W. Domier, Jian Wang, Z. G. Xia, Zuowei Shen

Chin. Phys. B 2009, 18 (3): 01153; doi: 10.1088/1674-1056/18/3/052
Full Text: PDF (588KB) (
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The fluctuation of the electron temperature has been measured by
using the electron cyclotron emission imaging in the Hefei Tokamak-7
(HT-7) plasma. The electron temperature fluctuation with a broadband
spectrum shows that it propagates in the electron diamagnetic drift
direction, and the mean poloidal wave-number \bar{k}_{θ} is
calculated to be about 1.58 cm^{-1}, or
\bar{k}_{θ} ρ_{s}≈ 0.34. It indicates that the
fluctuation should come from the electron drift wave turbulence. The
linear global scaling of the electron temperature fluctuation with
the gradient of electron temperature is consistent with the mixing
length scale qualitatively. Evolution of spectrum of the fluctuation
during the sawtooth oscillation phases is investigated, and the
fluctuation is found to increase with the gradient of electron
temperature increasing during most phases of the sawtooth
oscillation. The results indicate that the electron temperature
gradient is probably the driver of the fluctuation enhancement. The
steady heat flux driven by electron temperature fluctuation is
estimated and compared with the results from power balance
estimation.

The usual (1+1)-dimensional Schwartz Boussinesq equation is extended
to the (1+1)-dimensional space--time symmetric form and the general
(n+1)-dimensional space--time symmetric form. These extensions are
Painlevé integrable in the sense that they possess the Painlevé
property. The single soliton solutions and the periodic travelling
wave solutions for arbitrary dimensional space--time symmetric form
are obtained by the Painlevé—B?acklund transformation.

This paper studies the collision dynamics of bright soliton in
Bose--Einstein condensate with trapezoid potential. It is found that
besides the total reflection and total transmission, one bright
soliton can be divided into two bright solitons with different
amplitudes in a controllable manner.

Plasmas with vertically elongated cross-sections tend to be unstable
to an axis-symmetric instability. This paper studies the
magnetohydrodynamic equilibria in elongated plasmas after failure of
vertical feedback control by using magnetic data for EAST device.
Vertical forces on the vessel due to the induced polodial and
toroidal currents are evaluated. The maximum force of the Fz_{pol} in vertical displacement events for EAST designed parameters
is given.

This paper reports that a simulation of glow discharge in pure
helium gas at the pressure of 1.333×10^{3} Pa under a
high-voltage nanosecond pulse is performed by using a
one-dimensional particle-in-cell Monte Carlo collisions (PIC--MCC)
model. Numerical modelling results show that the cathode sheath is
much thicker than that of anode during the pulse discharge, and that
there exists the phenomenon of field reversal at relative high
pressures near the end of the pulse, which results from the
cumulative positive charges due to their finite mobility during the
cathode sheath expansion. Moreover, electron energy distribution
function (EEDF) and ion energy distribution function (IEDF) have
been also observed. In the early stage of the pulse, a large amount
of electrons can be accelerated above the ionization threshold
energy. However, in the second half of the pulse, as the field in
bulk plasma decreases and thereafter the reverse field forms due to
the excessive charges in cathode sheath, although the plasma density
grows, the high energy part of EEDF decreases. It concludes that the
large volume non-equilibrium plasmas can be obtained with
high-voltage nanosecond pulse discharges.

CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES

The microscopic structures and the bonding properties of Y-doped and undoped (01\bar {1}8)/[04\bar {4}1]/180° (∑37) grain boundaries in alumina are investigated by using \textit{ab initio} method. The formation energy of grain boundary and the segregation energy of Y to grain boundary are acquired. Electronic structures, potential distributions, bond orders and effective charges of Y-doped and undoped ∑37 GB systems are calculated. Our results reveal that the higher strength Y--O bond than Al--O bond is ascribed to the hybridization of Y(4p, 3d) with O(2s). Meanwhile, dopant Y also causes a change in potential distribution in the grain boundary region, thereby further affecting the transport property of ceramic alumina.

Repeater optimization is the key for SOC (System on Chip)
interconnect delay design. This paper proposes a novel optimal model
for minimizing power and area overhead of repeaters while meeting
the target performance of on-chip interconnect lines. It also
presents Lagrangian function to find the number of repeaters and
their sizes required for minimizing area and power overhead with
target delay constraint. Based on the 65 nanometre CMOS technology,
the computed results of the intermediate and global lines show that
the proposed model can significantly reduce area and power of
interconnected lines, and the better performance will be achieved
with the longer line. The results compared with the reference paper
demonstrate the validity of this model. It can be integrated into
repeater design methodology and CAD (computer aided design) tool for
interconnect planning in nanometre SOC.

Using first-principles techniques, we investigate the (001) surfaces
of cubic PbHfO_{3} (PHO) and BaHfO_{3} (BHO) terminated with
both AO (A=Pb and Ba) and HfO_{2}. Surface structure, partial
density of states, band structure, and surface energy are obtained.
The BaO surface is found to be similar to its counterpart in BHO.
For the HfO_{2}-terminated surface of cubic PHO, the largest
relaxation appears on the second-layer atoms but not on the
first-layer ones. The analysis of the structure relaxation
parameters reveals that the rumpling of the (001) surface for PHO is
stronger than that for BHO. The surface thermodynamic stability is
explored, and it is found that both the PbO- and the BaO-terminated
surfaces are more stable than the HfO_{2}-terminated surfaces for
PHO and BHO, respectively. The surface energy calculations show that
the (001) surface of PHO is more easily constructed than that of
BHO.

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

This paper studies the effects of He atom on the spin-polarized
electronic properties of nickel under pressures using {\it ab
initio} pseudopotential plan-wave method. Under high pressures, the
compound of NiHe_{0.25} can exist and helium-bubble can not create
in Ni. A pressure-induced ferromagnetic to paramagnetic phase
transition has been predicted in NiHe_{0.25} at about 218 GPa. It
is found that under pressures, the magnetic property of Ni atoms is
more strongly affected by He atom than by H atom and that the
behaviour of He atom in Ni are completely different from that of H
atom, like the bonding characteristics and the electron transfer.

Structural, thermodynamic and electronic properties of zinc-blende
AlN under pressure are investigated by first-principles calculations
based on the plane-wave basis set. Through the analysis of enthalpy
variation of AlN in the zinc-blende (ZB) and the rock-salt (RS)
structures with pressure, we find the phase transition of AlN from
ZB to RS structure occurs at 6.7 GPa. By using the quasi-harmonic
Debye model, we obtain the heat capacity C_{V}, Debye temperature
Θ_{D}, Grüneisen parameter γ and thermal
expansion coefficient α. The electronic properties including
fundamental energy gaps and hydrostatic deformation potentials are
investigated and the dependence of energy gaps on pressure is
analysed.

We study the time evolution of a state vector in a square
tight-binding lattice, focusing on its evolution localized over the
system surfaces. In this tight-binding lattice, the energy of atomic
orbital centred at surface site is different from that at the
interior (bulky) site by an energy shift U. It is shown that for
the state vector initially localized on a surface, there exists an
exponential law (y=a\e^{x/b+y0}) determined by the absolute
value of the energy shift, |U|, which describes the
transition of the state evolving on the square tight-binding
lattice, from delocalized over the whole lattice to localized over
the surfaces.

This paper reports that the multi-walled carbon nanotubes
(MWCNT)/nylon-6 (PA6) nanocomposites with different MWCNT loadings
have been prepared by a simple melt-compounding method. The
electrical, dielectric, and surface wetting properties of the
CNT/PA6 composites have been studied. The temperature dependence of
the conductivity of the CNT/PA6 composite with 10.0wt% CNT
loading (σ_{RT}～ 10^{4}S/cm) are measured, and
afterwards a charge-energy-limited tunnelling model (ln σ (T)
～T^{-1/2}) is found. With increasing CNT weight percentage from
0.0 to 10.0 wt%, the dielectric constant of the CNT/PA6
composites enhances and the dielectric loss tangent increases two
orders of magnitude. In addition, water contact angles of the
CNT/PA6 composites increase and the composites with CNT loading
larger than 2.0wt% even become hydrophobic. The obtained
results indicate that the electrical and surface properties of the
composites have been significantly enhanced by the embedded carbon
nanotubes.

This paper investigates the frequency-selective property of a planar
layer consisting of period arrays both theoretically and
experimentally for different polarizations at arbitrary incident
angle. The novel element is designed by loading the rectangular
microstrip element with L-shaped conducting patch at its two ends.
Based on the spectral-domain method, the frequency response
including angle effect and polarization effect of the frequency
selective surface (FSS) structure are analysed and the plots of the
frequency versus transmission coefficient are obtained. As a result
of the numerical analysis, it is shown that if the source
polarization is changed, polarization-independence of previous FSS
design can be achieved only for normal incidence, which limits most
FSS applications. But in our proposed structure, the better
polarization-independency for arbitrary incident angle can be
achieved. It is observed that the simulated result comes very close
to the experimental result.

This paper proposes an oxide filled extended trench gate super
junction (SJ) MOSFET structure to meet the need of higher frequency
power switches application. Compared with the conventional trench
gate SJ MOSFET, new structure has the smaller input and output
capacitances, and the remarkable improvements in the breakdown
voltage, on-resistance and switching speed. Furthermore, the SJ in the
new structure can be realized by the existing trench etching and
shallow angle implantation, which offers more freedom to SJ MOSFET
device design and fabrication.

This paper investigates a simplified metal induced crystallization
(MIC) of a-Si, named solution-based MIC (S-MIC). The nickel inducing
source was formed on a-Si from salt solution dissolved in de-ionized
water or ethanol. a-Si thin film was deposited with low pressure
chemical vapour deposition or plasma enhanced chemical vapour
deposition as precursor material for MIC. It finds that the content
of nickel source formed on a-Si can be controlled by solution
concentration and dipping time. The dependence of crystallization
rate of a-Si on annealing time illustrated that the linear density
of nickel source was another critical factor that affects the
crystallization of a-Si, besides the diffusion of nickel disilicide.
The highest electron Hall mobility of thus prepared S-MIC poly-Si is
45.6cm^{2}/(V.s). By using this S-MIC poly-Si, thin
film transistors and display scan drivers were made, and their
characteristics are presented.

Resonant tunnelling diodes (RTDs) have negative differential
resistance effect, and the current--voltage characteristics change
as a function of external stress, which is regarded as
meso-piezoresistance effect of RTDs. In this paper, a novel micro-accelerometer based on AlAs/GaAs/In_{0.1}Ga_{0.9}As/GaAs/AlAs
RTDs is designed and fabricated to be a four-beam-mass structure,
and an RTD-Wheatstone bridge measurement system is established to
test the basic properties of this novel accelerometer. According to
the experimental results, the sensitivity of the RTD based micro-accelerometer is adjustable within a range of 3 orders when the bias
voltage of the sensor changes. The largest sensitivity of this RTD
based micro-accelerometer is 560.2025 mV/g which is about 10 times
larger than that of silicon based micro piezoresistive
accelerometer, while the smallest one is 1.49135 mV/g.

This paper predicts the elastic and thermodynamic characteristics of
TiB_{2} crystal through the method of density functional theory
within the generalized gradient approximation (GGA). The five
independent elastic constants (C_{ij}), the bulk modulus
(B_{0}), the dependence of bulk modulus (B_{0}) on temperature
T and pressure P and the coefficient of thermal expansion
(α_{L}) at various temperatures have been evaluated and
discussed. According to calculation, the bulk modulus will increase
with increasing pressure while decrease with the increasing
temperature. The coefficient of thermal expansion is consistent with
the famous Grüneisen's law when the temperature is not too high.
The obtained results agree well with the experimental and other
theoretical results.

The local structure distortion, the spin Hamiltonian (SH)
parameters, and the electric fine structure of the ground state for
Mn^{2+}(3d^{5}) ion in ZnO crystals are systematically
investigated, where spin--spin (SS), spin--other--orbit (SOO) and
orbit--orbit (OO) magnetic interactions, besides the well-known
spin--orbit (SO) coupling, are taken into account for the first
time, by using the complete diagonalization method. The theoretical
results of the second-order zero-field splitting (ZFS) parameter
D, the fourth-order ZFS parameter (a-F), the Zeeman
g-factors: g_{//} and g_{⊥}, and the energy differences of
the ground state: \delta_{1} and \delta_{2} for Mn^{2+} in
Mn^{2+}: ZnO are in good agreement with experimental measurements
when the three O^{2-} ions below the Mn^{2+} ion rotate by
1.085^{o} away from the [111]-axis. Hence, the local structure
distortion effect plays an important role in explaining the
spectroscopic properties of Mn^{2+} ions in Mn^{2+}: ZnO
crystals. It is found for Mn^{2+} ions in Mn^{2+}: ZnO crystals
that although the SO mechanism is the most important one, the
contributions to the SH parameters, made by other four mechanisms,
i.e. SS, SOO, OO, and SO～SS～SOO～OO mechanisms, are
significant and should not be omitted, especially for calculating
ZFS parameter D.

This paper reports that amorphous magnetic microwires
(Fe_{79}Si_{16}B_{5}) have been fabricated by a
melt-extraction technique and have been annealed at 600℃ and
750℃ respectively. Differential scanning calorimeter
measurements show that nanocrystalline magnetic phase (α-Fe)
has been formed in the amorphous matrix when it was annealed at
600℃. Hard magnetic phase (Fe_{2}B) was formed in the
microwires annealed at 750℃, which increases the magnetic
coercivity. Microwave permittivity and permeability are found to be
dependent on the microstructures. The permittivity fitting results
show that multi Lorentzian dispersion processes exist. For
microwires annealed at 750℃, their resonance peaks due to
the domain wall movements and natural resonance are found higher
than those of microwires annealed at 600℃. The microwave
absorption performance of microwires annealed at 600℃ is
found better than microwires annealed at 750℃.

This paper investigates the effect of growth temperature on
morphology, structure and photoluminescence (PL) of Tb-doped boron
nitride (BN) films grown by magnetron sputtering, and the
relationships of growth-temperature-structure-PL by scanning
electron microscopy, transmission electron microscopy and PL. The
characteristic emission lines of the Tb^{3+} were observed in the
PL spectra at room temperature. The 473-K-grown film is mainly
consisted of amorphous BN particles. With the growth temperature
increasing up to 1273 K, the amount of amorphous BN decreases,
while the amount of turbostratic BN increases. Correspondingly, the
PL intensities from the Tb^{3+} ions increase with the increase of
temperature in the range of 473--1273 K.

A period-varying folded waveguide is formed by varying the period of
a folded waveguide. It has the advantages of the space harmonic
selectivity and the wide bandwidth. However, the regularities of the
variety of these period-varying folded waveguides are unavailable
from the published papers. In order to solve this problem, the
principle of the space harmonic selectivity of a period-varying
folded waveguide is analysed, and the conditions to select the space
harmonic for this slow wave system are obtained. In addition, the
space harmonic selectivities for a linear period-varying folded
waveguide and a hyperbolic sine-varying period folded waveguide are
also analysed as examples.

8000 CROSSDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY

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