The dynamics of two coupled spins-1/2 coupled to a spin-bath is
studied as an extended model of the Tessieri--Wilkie Hamiltonian. The
pair of spins served as an open subsystem is prepared in one of the
Bell states and the bath consisting of some spins-1/2 is in a thermal
equilibrium state from the very beginning. It is found that with
increasing coupling strength of the bath spins, the bath forms a
resonant antiferromagnetic order. The polarization correlation
between the two spins of the subsystem and the concurrence of it are
recovered to some extent in the isolated subsystem. This suppression
of the subsystem decoherence may be used to control the quantum
devices in practical applications.

This paper constructs more general exact solutions than $N$-soliton
solution and Wronskian solution for variable-coefficient
Kadomtsev--Petviashvili (KP) equation. By using the Hirota method
and Pfaffian technique, it finds the Grammian determinant-type
solution for the variable-coefficient KP equation (VCKP), the
Wronski-type Pfaffian solution and the Gram-type Pfaffian solutions
for the Pfaffianized VCKP equation.

In this paper the energy diffusion controlled reaction rate in dissipative Hamiltonian
systems is investigated by using the stochastic averaging method for quasi
Hamiltonian systems. The boundary value problem of mean first-passage time
(MFPT) of averaged system is formulated and the energy diffusion controlled
reaction rate is obtained as the inverse of MFPT. The energy diffusion
controlled reaction rate in the classical Kramers bistable potential and in
a two-dimensional bistable potential with a heat bath are obtained by using
the proposed approach respectively. The obtained results are then compared
with those from Monte Carlo simulation of original systems and from the
classical Kramers theory. It is shown that the reaction rate obtained by
using the proposed approach agrees well with that from Monte Carlo
simulation and is more accurate than the classical Kramers rate.

This paper studies the perturbation to symmetries and adiabatic
invariant for nonholonomic controllable mechanical systems with
non-Chetaev type constraints. It gives the exact invariants
introduced by the Lie symmetries of the nonholonomic controllable
mechanical system with non-Chetaev type constraints without
perturbation. Based on the definition of high-order adiabatic
invariants of mechanical system, the perturbation of Lie symmetries
for nonholonomic controllable mechanical system with non-Chetaev type
constraints with the action of small disturbances is investigated,
and a new type of adiabatic invariant of system are obtained. In the
end of this paper, an example is given to illustrate the application
of the results.

This paper studies the unified symmetry of a nonholonomic system of
non-Chetaev type with unilateral constraints in event space under
infinitesimal transformations of group. Firstly, it gives the
differential equations of motion of the system. Secondly, it obtains
the definition and the criterion of the unified symmetry for the
system. Thirdly, a new conserved quantity, besides the Noether
conserved quantity and the Hojman conserved quantity, is deduced from
the unified symmetry of a nonholonomic system of non-Chetaev type
with unilateral constraints. Finally, an example is given to
illustrate the application of the results.

We solve the generalized nonlinear Schr\"{o}dinger equation
describing the propagation of femtosecond pulses in a nonlinear
optical fibre with higher-order dispersions by using the direct
approach to perturbation for bright solitons, and discuss the
combined effects of the third- and fourth-order dispersions on
velocity, temporal intensity distribution and peak intensity of
femtosecond pulses. It is noticeable that the combined effects of the
third- and fourth-order dispersions on an initial propagated soliton
can partially compensate each other, which seems to be significant
for the stability controlling of soliton propagation features.

Using a new symmetry group theory, the transformation groups and
symmetries of the general Broer--Kaup system are obtained. The
results are much simpler than those obtained via the standard
approaches.

The coupled nonlinear Schr\"{o}dinger equations (CNLSEs) of two
symmetrical optical fibres are nonintegrable, however the transformed
CNLSEs have integrability. Integrability of the transformed CNLSEs is
proved by the Hamilton dynamics theory and Galilei transform. Making
use of a transform for CNLSEs and using the ansatz with Jacobi
elliptic function form, this paper obtains the exact optical pulse
solutions.

Beyond the Lamb--Dicke limit, this paper investigates the squeezing
properties of the trapped ion in the travelling-wave laser. It shows
that the squeezing properties of the trapped ion in the
travelling-wave laser are strongly affected by the sideband number
$k$, the Lamb--Dicke parameter $\eta$ and the initial average phonon
number.

In this paper, we study the Wigner function of coherent state of $N$
components, especially two components and three components. This
function consists of two terms: the Gaussian term and the
interference term with the negativity. The first term comprises $N$
Gaussian surfaces evenly centred on a circle of radius
$|\beta|=|\alpha|$ with a separate angle of
${2\pi}/{N}$, and the second term is composed of
$\frac{1}{2}N(N-1)$ Gaussian-cosine surfaces evenly centred in a
circular region of radius $|\beta|<|\alpha|$. Here, $\alpha$ is the
eigenvalue of the annihilation operator $a$, and $\beta$ is a
variable in some complex space in which the Wigner function is
defined. We have proved that the essential condition to eliminate the
negativity of the Wigner function is that the mean photon count of
the coherent state is equal to that of the Glouber coherent state.

Based on the idea that a squeezing process can be thought of as a
total cumulative effect of a large number of tiny squeezing
processes, we define a squeeze-like operator with a time-dependent
squeeze parameter. Applying this operator to and combining with a
system which includes a two-photon interaction between two atoms and
an initial vacuum cavity field, and resorting to a resonant strong
driving classical field, we obtain an unconventional geometric phase
gate with a shorter gating time.

We propose a scheme to implement two-qubit controlled quantum phase
gate(CQPG) via a single trapped two-level ion located
in the standing wave field of a quantum cavity, in which the trap works
beyond the Lamb--Dicke limit.
When the
light field is resonant with the atomic transition
$|g\rangle\leftrightarrow|e\rangle$ of the ion located at the
antinode of the standing wave, we can perform CQPG between the
internal and external states of the trapped ion; while the frequency
of the light field is chosen to be resonant with the first red
sideband of the collective vibrational mode of the ion located at
the node of the standing wave, we can perform CQPG between the
cavity mode and the collective vibrational mode of the trapped ion.
Neither the Lamb--Dicke approximation nor the assistant classical
laser is needed. Also we can generate a GHZ state if assisted with
a classical laser.

In this paper, the speed gradient (SG) model is extended to describe
the traffic flow on two-lane freeways. Terms related to lane change
are added into the continuity equations and velocity dynamic
equations. The empirically observed two-lane phenomena, such as lane
usage inversion and lane change rate versus density, are reproduced
by extended SG model. The local cluster effect is also investigated
by numerical simulations.

Many unique properties of complex networks result from heterogeneity. The measure and analysis of heterogeneity are
important and desirable to the research of the properties and
functions of complex networks. In this paper, the rank distribution
is proposed as a new statistic feature of complex networks. Based on
the rank distribution, a novel measure of the heterogeneity called a
normalized entropy of rank distribution (NERD) is proposed. The NERD
accords with the normal meaning of heterogeneity within the context
of complex networks compared with conventional measures. The
heterogeneity of scale-free networks is studied using the NERD. It
is shown that scale-free networks become more heterogeneous as the
scaling exponent decreases and the NERD of scale-free networks is
independent of the number of vertices, which indicates that the NERD
is a suitable and effective measure of heterogeneity for networks
with different sizes.

Aimed at lowering the effect of `rich get richer' in scale-free
networks with the Barab\'{a}si and Albert model, this paper
proposes a new evolving mechanism, which
includes dividing and preference attachment for the growth of a
network. A broad scale characteristic which is independent of the
initial network topology is obtained with the proposed model. By
simulating, it is found that preferential attachment causes the
appearance of the scale-free characteristic,
while the dividing will decrease the power-law behaviour and
drive the evolution of broad scale networks.

In this paper, chaotic behaviours in the fractional-order Liu system
are studied. Based on the approximation theory of fractional-order
operator, circuits are designed to simulate the fractional- order
Liu system with $q=0.1-0.9$ in a step of 0.1, and an experiment has
demonstrated the 2.7-order Liu system. The simulation results prove
that the chaos exists indeed in the fractional-order Liu system with
an order as low as 0.3. The experimental results prove that the
fractional-order chaotic system can be realized by using hardware
devices, which lays the foundation for its practical applications.

This paper deals with the problem of chaos control and
synchronization of the Chen--Liao system. From rigorous mathematic
justification, the chaotic trajectories of the Chen--Liao system are
led to a type of points whose four-dimensional coordinates have a
particular functional relation among them. Meanwhile, a new
synchronization manner, reduced-order generalized synchronization
(RGS), is proposed which has the characteristic of having a
functional relation between the slave and the partial master systems.
It is shown that this new synchronization phenomenon can be realized
by a novel technique. Numerical simulations have verified the
effectiveness of the proposed scheme.

In this paper, we apply a simple adaptive feedback control scheme to
synchronize two bi-directionally coupled chaotic systems. Based on
the invariance principle of differential equations, sufficient
conditions for the global asymptotic synchronization between two
bi-directionally coupled chaotic systems via an adaptive feedback
controller are given. Unlike other control schemes for
bi-directionally coupled systems, this scheme is very simple to
implement in practice and need not consider coupling terms. As
examples, the autonomous hyperchaotic Chen systems and the new
non-autonomous 4D systems are illustrated. Numerical simulations show
that the proposed method is effective and robust against the effect
of weak noise.

This paper presents chaos synchronization between two different chaotic
systems by using a nonlinear controller, in which the nonlinear functions of
the system are used as a nonlinear feedback term. The feedback controller is
designed on the basis of stability theory, and the area of feedback gain is
determined. The artificial simulation results show that this control method
is commendably effective and feasible.

This paper investigates the dynamical behaviour of network traffic
flow. Assume that trip rates may be influenced by the level of
service on the network and travellers are willing to take a faster
route. A discrete dynamical model for the day-to-day adjustment
process of route choice is presented. The model is then applied to a
simple network for analysing the day-to-day behaviours of network
flow. It finds that equilibrium is arrived if network flow consists
of travellers not very sensitive to the differences of travel cost.
Oscillations and chaos of network traffic flow are also found when
travellers are sensitive to the travel cost and travel demand in a
simple network.

This paper proposes a method of generating multipartite entanglement through using
d.c.\ superconducting quantum interference devices (SQUID) inside a standing
wave cavity. In this scheme, the d.c.\ SQUID works in the charge region. It
is shown that, a large number of important multipartite entangled states can
be generated by a controllable interaction between a cavity field and
qubits. It is even possible to produce entangled states involving different
cavity modes based on the measurement of charge qubits states. After such
superpositions states are created, the interaction can be switched off by
the classical magnetic field through the SQUID, and there is no information
transfer between the cavity field and the charge qubits.

Hidden Markov models (HMMs) have been used to model burst error
sources of wireless channels. This paper proposes a hybrid method of
using genetic algorithm (GA) and simulated annealing (SA) to train
HMM for discrete channel modelling. The proposed method is compared
with pure GA, and experimental results show that the HMMs trained by
the hybrid method can better describe the error sequences due to SA's
ability of facilitating hill-climbing at the later stage of the
search. The burst error statistics of the HMMs trained by the
proposed method and the corresponding error sequences are also
presented to validate the proposed method.

A shaped annular beam tri-heterodyne confocal microscope has been proposed
to improve the anti-environmental interference capability and the resolution
of a confocal microscope. It simultaneously detects far-, on-, and
near-focus signals with given phase differences by dividing the measured
light path of the confocal microscope into three sub-paths (signals).
Pair-wise real-time heterodyne subtraction of the three signals is used to
improve the anti-environmental interference capability, axial resolution,
and linearity; and a shaped annular beam super-resolution technique is used
to improve lateral resolution. Theoretical analyses and preliminary
experiments indicate that an axial resolution of about 1 nm can be achieved
with a shaped annular beam tri-heterodyne confocal microscope and its
lateral resolution can be better than 0.2 $\mu $m for $\lambda =632.8$~nm,
the numerical aperture of the lens of the microscope is NA $=0.85$, and the
normalized radius $\varepsilon =0.5$.

This paper gives theoretical analysis of visibility of fringes,
which is influenced by distances, temporal and spatial coherence
of source, in hard x-ray differential phase-contrast imaging
with microfocus x-ray source. According to the character of
longitudinal periodicity of the interferogram, the setup is
insensitive to mechanical drift and vibrations. The effect of
temporal coherence of x-ray source is investigated and its
related bandwidth is derived. Based on the theory of partially
coherent light, it shows that the requirement for the spatial
coherence of x-ray source is not strict and can be met by the
general microfocus x-ray tube for x-ray differential
phase-contrast imaging.

Based on a new screening Coulomb model, this paper discusses the effect of
electron screening on proton capture reaction of $^{23}$Mg. The derived
result shows that, in some considerable range of stellar temperatures, the
effect of electron screening on resonant reaction is prominent; on the
non-resonant reaction the effect is obvious only in the low stellar
temperatures. The reaction rates of $^{23}$Mg(p,$\gamma )^{24}$Al would
increase 15\%--25{\%} due to the fact that the electron screening are
considered in typical temperature range of massive mass white dwarfs, and
the results undoubtedly affect the nucleosynthesis of some heavier nuclei in
massive mass white dwarfs.

The algebraic energy method (AEM) is applied to the study of
molecular dissociation energy $D_e$ for 11 heteronuclear diatomic
electronic states: $a^3\Sigma^+$ state of NaK, $X^2\Sigma^+$ state
of XeBr, $X^2\Sigma^+$ state of HgI, $X^1\Sigma^+$ state of LiH,
$A^3\Pi(1)$ state of ICl, $X^1\Sigma^+$ state of CsH, $A(^3\Pi_1)$
and $B0^+(^3\Pi)$ states of ClF, $2^1\Pi$ state of KRb,
$X^1\Sigma^+$ state of CO, and $c^3\Sigma^+$ state of NaK molecule.
The results show that the values of $D_e$ computed by using the AEM
are satisfactorily accurate compared with experimental ones. The AEM
can serve as an economic and useful tool to generate a reliable
$D_e$ within an allowed experimental error for the electronic states
whose molecular dissociation energies are unavailable from the
existing literature.

This paper reports that the ultraviolet and visible upconversion luminescence from the
$^{4}\S_{3 / 2}$, $^{2}\G_{9 / 2}$ and $^{2}\P_{3 / 2}$ levels have been
observed in Er$^{3 + }$:YAG following 647.2~nm excitation of the
$^{4}\F_{9 / 2}$ multiple. Upconversion luminescence intensity dependence on
pump power was recorded. The measured decay profiles were theoretically
fitted by kinetics theory and the basically good agreements were achieved.
The results indicate that some energy transfer processes proposed to explain
the observed upconversion phenomena are reasonable.

A complex optical model potential modified by incorporating the
concept of bonded atom, which takes into consideration the
overlapping effect of electron clouds between atoms in a molecule, is
firstly employed to calculate the absolute differential, elastic
integrated and moment transfer cross sections for electron scattering
by OCS over the incident energy range from 200 to 1000\,eV using the
additivity rule model at Hartree--Fock level. The calculated results
are compared with those obtained by experiment and other theories
wherever available, and good agreement is obtained over a wide energy
range. It is shown that the additivity rule model together with the
modified potential is completely suitable for calculating the
absolute differential, elastic integrated and moment transfer cross
sections of electron scattering by molecules such as OCS.

A systematic study on the structure and electronic properties of gold
clusters doped each with one copper atom has been performed using the
density functional theory. The average bond lengths in the Au$_{n -
1}$Cu ($n \le 9$) bimetallic clusters are shorter than those in
the corresponding pure gold clusters. The ionization potentials of
the bimetallic clusters Au$_{n-1}$Cu ($n \le 9$) are larger than
those of the corresponding homoatomic gold clusters except for
Au$_{5}$. The energy gaps of the Au--Cu binary clusters are narrower
than those of the Au$_{n}$ clusters except AuCu and Au$_{3}$Cu. No
obvious even--odd effect exists in the variations of the electron
affinities and ionization potentials for the Au$_{n - 1}$Cu ($n \le
$ 9) clusters, which is in contrast to the case of gold clusters
Au$_{n}$.

The liquid crystal spatial light modulator (LC SLM) is very suitable
for wavefront correction and optical testing and can produce a
wavefront with large phase change and high accuracy. The LC SLM is
composed of thousands of pixels and the pixel size and shape have
effects on the diffractive characteristics of the LC SLM. This paper
investigates the pixel effect on the phase of the wavefront with the
scalar diffractive theory. The results show that the maximum optical
path difference modulation is 41\,$\mu$m to produce the paraboloid
wavefront with the peak to valley accuracy better than $\la$/10.
Effects of the mismatch between the pixel and the period, and black
matrix on the diffraction efficiency of the LC SLM are also analysed
with the Fresnel phase lens model. The ability of the LC SLM is
discussed for optical testing and wavefront correction based on the
calculated results. It shows that the LC SLM can be used as a
wavefront corrector and a compensator.

The influence of degenerate four-wave mixing (FWM) on the performance of
supercontinuum-based multiwavelength optical source has been investigated in
detail experimentally and theoretically. Numerical simulation results show
that the degenerate FWM effect has a deteriorative influence on the spectral
uniformity and the optical signal-to-noise ratio (OSNR) of
supercontinuum-based optical source, and by suppressing degenerate FWM
effect the performance enhancement of the supercontinuum can be achieved
successfully. These results are also confirmed by our experiments.
Experimentally, by suppressing degenerate FWM the crosstalk of adjacent
channels to the filtered channel can be reduced by as much as 15 dB, and
consequently the measured receiver sensitivity at 10 Gbit/s for the filtered
optical source is improved from $-1.7$ to $-17.8$~dBm.

This paper proposes a scheme for teleporting a two-atom entangled
state using leaky cavities. It uses resonant atom--cavity interaction
to map the atomic state onto the cavity field. Then it utilizes the
interference of polarized photons to establish the correlation
between the distant sender and receiver. The advantage of the scheme
is that the fidelity is independent of the cavity decay rate, atomic
decay and detection efficiency.

This paper investigates the effects of walk-off among optical pulses
on cross-phase modulation induced modulation instability in the
normal dispersion region of an optical fibre with high-order
dispersion. The results indicate that, in the case of high-order
dispersion, the walk-off effect takes on new characteristics and will
influence considerably the shape, position and especially the number
of the spectral regions of the gain spectra of modulation
instability.
Not only the group-velocity mismatch, but also the difference
of the third-order dispersion of two optical waves will alter the gain
spectra of modulation instability but in different ways. Depending on the
values of the walk-off parameters, the number of the spectral regions may
increase from two to at most four, and the spectral shape and position may
change too.

This paper studies the focusing properties of a two-dimensional
photonic crystal (PC) slab consisting of a triangular lattice of
metallic cylinders immersed in a dielectric background. Through the
analysis of the equifrequency-surface contours and the field
patterns of a point source placed in the vicinity of the PC slab, it
finds that both the image distance and image quality can be
controlled by simply adjusting the refractive index of the
background material.

Temperature and strain characteristics of uniform fibre grating with
tapered metal coatings have been analysed theoretically, by which
adjustable chirp characteristics of such gratings are shown.
Electroplating is adopted to fabricate such gratings, and the tapered
metal coating is obtained by gradually drawing the fibre grating out
of the solution during the process of electroplating. The gradually
changing cross-sectional area of the metal coating is calculated by a
newly suggested numerical method. By combining the theoretical and
numerical simulation analyses, the gratings' characteristics are
given at various temperatures and strains. The results obtained using
such a method are also testified by experiments.

A chirped fibre Bragg grating according to ITU-T suggested L-band
(2nd channel $\lambda _{1}=1570.83$~nm; 80th channel $\lambda
_{2}=1603.57$ nm) with more than 1800 ps/nm single channel dispersion
compensation is presented in this paper, of which the cladding mode
loss, the delay curve ripple and the power fluctuation of the
reflected spectrum are less than 0.5 dB, 50 ps and 0.25 dB,
respectively. With this new FBG as dispersion compensation device, a
$2\times 10$ Gb/s wavelength division multiplexing (WDM) L-band
transmission of 600 km based on conventional single mode fibre (G.652
fibre) is performed without forward error correction. The bit error
rate (BER) is less than 10$^{ - 12}$ and the power penalties of the
2{nd} and 80{th} channel of L-band are 1.8~dB and 2.0~dB,
respectively.

This paper describes the research on the materials and design methods
for advanced smart radiator devices (SRDs) on large-area flexible
substrates utilized on spacecraft. The functional material is
thermochromic vanadium dioxide. The coating design of SRD is similar
to the design of broadband filter coatings in a mid-infrared region.
The multilayer coatings have complex structures. Coating materials
must be highly transparent in a required spectrum region and also
mechanically robust enough to endure the influence from the rigorous
environments of outer space. The number of layers must be very small,
suitable for the deposition on large-area flexible substrates. All
the coatings are designed initially based on optical calculation and
practical experience, and then optimized by the TFCALC software.
Several designs are described and compared with each other. The
results show that the emittance variability of the designed SRDs is
great than 400\%, more advanced than the reported ones.

A novel single-mode single-polarization (SMSP) photonic crystal fibre
has been proposed and analysed based
on the polarization-dependent coupling and absorption effect via a full-vector finite element method with perfectly matched
layers. The numerical results predict that very efficient SMSP operation can
be achieved with both high bandwidth and high extinction ratio at low loss
penalty. Effects of the fibre structural parameters on the SMSP bandwidth
and extinction ratio have been explored, which will provide useful
guide for the design and fabrication of the fibre. The results obtained
will be instructive for the realization of new SMSP fibres with high
performance.

In this paper, polarization properties and propagation
characteristics of polymer photonic crystal fibres with elliptical
core and non-hexagonal symmetry structure are investigated by using
the full vectorial plane wave method. The results show that the
birefringence of the fibre is induced by asymmetries of both the
cladding and the core. Moreover, by adjusting the non-symmetrical
ratio factor of cladding $\eta$ from 0.4 to 1 in step 0.1, we find
the optimized design parameters of the fibre with high
birefringence and limited polarization mode dispersion, operating in
a single mode regime at an appropriate wavelength range. The range of
wavelength approaches the visible and near-infrared which is
consistent with the communication windows of polymer optical fibres.

CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES

In this paper a systematic ferromagnetic resonance study shows that an in-plane
magnetic anisotropy in the patterned micron octagon
permalloy (Ni$_{80}$Fe$_{20})$ elements is mainly determined by the element
geometry. The easy-axis is along the edge of the elements, and the hard-axis
is along the diagonal. The shape anisotropy of the octagon elements is
determined by square and equilateral octagon, and the theoretical calculation
was studied on the shape anisotropy. The shape anisotropy
of rectangular was calculated by using the same theory.

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

Nanocrystalline FeB alloys have been prepared with optimized grain
size and internal stress. Samples prepared under different annealing
conditions are analysed by x-ray diffraction, and the permeability
$\mu(\omega)$ is measured by HP8510B Vector Network Analyser in the
frequency range 2--18GHz. The results show that annealing leads to
the growth of the grain size and reduces the internal stress, and
smaller grain size and larger internal stress favours the magnetic
dissipation.

In this paper, we present a micromagnetic design for high field
sensors. The hard layer of the sensors is L1$_{0}$--FePt which is
magnetized perpendicularly to film plane and the sense layer is NiFe
which is magnetized in the film plane. The magnetization
configurations of the hard and sense layers at different external
magnetic fields have been simulated. In micromagnetic simulation, the
sense field up to one tesla can be reached by using this sensor. We
find that whether the sensor has a symmetric or an asymmetric
field-sensing window is determined by the coercive field of the hard
layer and the demagnetizing field of the sense layer.

Er$^{3+}$-doped lithium-potassium mixed alkali aluminophosphate
glasses belonging to the oxide system
$x$K$_2$O-(15-$x$)Li$_2$O-4B$_2$O$_3$-11Al$_2$O$_3$-5BaO-65P$_2$O$_5$
are obtained in a semi-continuous melting quenching process.
Spectroscopic properties of Er$^{3+}$-doped glass matrix have been
analysed by fitting the experimental data with the standard
Judd--Ofelt theory. It is observed that Judd--Ofelt intensity
parameters ${\it\Omega}_ t (t= 2$, 4 and 6) of Er$^{3+}$ change when
the second alkali is introduced into glass matrix. The variation of
line strength $S_{\rm ed}$[$^4$I$_{13/2}$,$^4$I$_{15/2}$] follows the
same trend as that of the ${\it\Omega}_6$ parameter. The effect of
mixed alkali on the spectroscopic properties of the aluminophosphate
glasses, such as absorption cross-section, stimulated emission
cross-section, spontaneous emission probability, branching ratio and
the radiative lifetime, has also been investigated in this paper.

The speed performance and static power dissipation of the
ultra-thin-body (UTB) MOSFETs have been comprehensively investigated,
with both DC and AC behaviours considered. Source/drain extension
width ($L_{\rm sp})$ and silicon film thickness $(t_{\rm si})$ are
two independent parameters that influence the speed and static power
dissipation of UTB silicon-on-insulator (SOI) MOSFETs respectively,
which can result in
great design flexibility. Based on the different effects
of physical and geometric parameters on device characteristics, a method to
alleviate the contradiction between power dissipated and speed of UTB SOI MOSFETs is
proposed. The optimal design regions of $t_{\rm si}$ and
$L_{\rm sp}$ for
low operating power and high performance logic applications are
given, which may shed light on the design of UTB SOI MOSFETs.

We investigate theoretically the electron transport for a two-level
quantum channel (wire) with Rashba spin--orbit coupling under the
irradiation of a longitudinally-polarized external laser field at low
temperatures. Using the method of equation of motion for Keldysh
nonequilibrium Green function, we examine the time-averaged spin
polarized conductance for the system with photon polarization
parallel to the wire direction. By analytical analysis and a few
numerical examples, the interplay effects of the external laser field
and the Rashba spin--orbit coupling on the spin-polarized conductance
for the system are demonstrated and discussed. It is found that the
longitudinally-polarized laser field can adjust the spin polarization
rate and produce some photon sideband resonances of the conductance
for the system.

This paper reports that the nickel silicide ohmic contacts to n-type
6H-SiC have been fabricated. Transfer length method test patterns
with NiSi/SiC and NiSi$_{2}$/SiC structure are formed on N-wells
created by N$^{ + }$ ion implantation into Si-faced p-type 6H-SiC
epilayer respectively. NiSi and NiSi$_{2}$ films are prepared by
annealing the Ni and Si films separately deposited. A two-step
annealing technology is performed for decreasing of oxidation
problems occurred during high temperature processes. The specific
contact resistance $\rho _{c}$ of NiSi contact to n-type 6H-SiC as
low as 1.78$\times $10$^{ - 6}\Omega $cm$^{2}$ is achieved after a
two-step annealing at 350~${^\circ}$C for 20 min and 950${^\circ}$C
for 3 min in N$_{2}$. And 3.84$\times $10$^{ - 6}\Omega $cm$^{2}$ for
NiSi$_{2}$ contact is achieved. The result for sheet resistance
$R_{\rm sh}$ of the N$^{ + }$ implanted layers is about 1210$\Omega
/\square$. X-ray diffraction analysis shows the formation of nickel
silicide phases at the metal/n-SiC interface after thermal annealing.
The surfaces of the nickel silicide after thermal annealing are
analysed by scanning electron microscope.

In this paper, a threshold voltage model for high-$k$ gate-dielectric
metal--oxide--semiconductor field-effect transistors (MOSFETs) is
developed, with more accurate boundary conditions of the gate
dielectric derived through a conformal mapping transformation method
to consider the fringing-field effects including the influences of
high-$k$ gate-dielectric and sidewall spacer. Comparing with similar
models, the proposed model can be applied to general situations where
the gate dielectric and sidewall spacer can have different dielectric
constants. The influences of sidewall spacer and high-$k$ gate
dielectric on fringing field distribution of the gate dielectric and
thus threshold voltage behaviours of a MOSFET are discussed in
detail.

Through magnetization measurement with a SQUID magnetometer the heat
treatment optimization of an international thermonuclear experimental
reactor (ITER)-type internal-Sn Nb$_{3}$Sn superconducting wire has been
investigated. The irreversibility temperature $T^*(H)$, which is mainly
dependent on A15 phase composition, was obtained by a warming and cooling
cycle at a fixed field. The hysteresis width $\Delta M(H)$ which reflects
the flux pinning situation of the A15 phase is determined by the sweeping
of magnetic field at a constant temperature. The results obtained from
differently heat-treated samples show that the combination of $T^*(H)$ with
$\Delta M(H)$ measurement is very effective for optimizing the heat reaction
process. The heat treatment condition of the ITER-type wire is optimized at
675$\,^\circ$C/128~h, which results in a composition closer to stoichiometric
Nb$_{3}$Sn and a state with best flux pinning.

This paper reports that the Zn$_{0.95}$Co$_{0.05}$O polycrystalline
powder and thin film were prepared by sol-gel technique under the
similar preparation conditions. The former does not show typical
ferromagnetic behaviour, while the latter exhibits obvious
ferromagnetic properties at 5 K and room temperature. The UV--vis
spectra and x-ray absorption spectra show that Co$^{2 + }$ ions are
homogeneously incorporated into ZnO lattice without forming secondary
phases. The distinct difference between film and powder sample is the
$c$-axis (002) preferential orientation indicated by the x-ray
diffraction pattern and field emission scanning electron microscopy
measurement, which may be the reason why Zn$_{0.95}$Co$_{0.05}$O film
shows ferromagnetic behaviour.

The quantum tunnelling of magnetization (QTM) in single crystals of
the single molecule magnet (Mn$_{1-x}$Cr$_x$)12-Ac ($x$=0, 0.03,
0.04, 0.05) has been investigated. In comparison with its parent
Mn12-Ac, a greater rate of magnetization relaxation and a lower
effective potential-energy barrier have been observed in Cr-doping
samples. This modulation of QTM due to the Cr-doping could be
attributed to the small change of $S_z$ due to the smaller spin of Cr
itself and additional intrinsic but distributed transverse and
longitudinal anisotropy raised by a subtle change of the local
environment in the magnetic Mn12 core.

We have performed the first-principles calculation to investigate the
origins of ferroelectricities and different polarization behaviours
of superlattices BaTiO$_{3}$/SrTiO$_{3}$ and PbTiO$_{3}$/SrTiO$_{3}$. The
density of state (DOS) and electronic charge profiles show that there are
strong hybridizations between atoms Ti and O and between atoms Pb and O
which play very important roles in producing the ferroelectricities of
superlattices BaTiO$_{3}$/SrTiO$_{3}$ and PbTiO$_{3}$/SrTiO$_{3}$. Owing to
the decline of internal electric field in SrTiO$_{3}$ (ST) layer, the
tetragonality and polarizations of superlattices decrease with increasing
the fraction of SrTiO$_{3}$ in the superlattices. We find that the
polarization of PbTiO$_{3}$/SrTiO$_{3}$ is larger$_{ }$than that of
BaTiO$_{3}$/SrTiO$_{3}$ at the same ratio of components, because the
polarization mismatch between PbTiO$_{3}$ and SrTiO$_{3}$ is larger than
that between BaTiO$_{3}$ and SrTiO$_{3}$. The polarization and tetragonality
are enhanced with respect to those of bulk tetragonal BaTiO$_{3}$ in the
superlattices BaTiO$_{3}$/SrTiO$_{3}$, while the polarization and
tetragonality are reduced with respect to those of bulk tetragonal
PbTiO$_{3}$ in superlattices PbTiO$_{3}$/SrTiO$_{3}$.

The absorption and emission spectra of the YVO$_4$ single crystal
co-doped with 1 at.\% Nd$^{3+}$ and 1 at.\% Yb$^{3+}$ are
investigated. The efficient Nd$^{3+}$ $\rightarrow$ Yb$^{3+}$ energy
transfer and the back transfer (Yb$^{3+}\rightarrow$ Nd$^{3+}$) are
observed at room temperature. The fluorescence lifetime of the
$^4$F$_{3/2}$ level of Nd$^{3+}$ in Nd,Yb:YVO$_4$ is measured under
808\,nm laser light excitation. The efficiency of
Nd$^{3+}\rightarrow$ Yb$^{3+}$ energy transfer in YVO$_4$ is
determined to be about 34\%.

A simplified n-ZnO/p-Si heterojunction has been prepared by growing
n-type ZnO rods on p-type silicon wafer through the chemical vapour
deposition method. The reflectance spectrum of the sample shows an
independent absorption peak at 384 nm, which may be originated from
the bound states at the junction. In the photoluminescence spectrum a
new emission band is shown at 393 nm, besides the bandedge emission
at 380 nm. The electroluminescence spectrum of the n-ZnO/p-Si
heterojunction shows a stable yellow luminescence band centred at 560
nm，which can be attributed to the emission from trapped states.
Another kind of discrete ZnO rod has also been prepared on such
silicon wafer and is encapsulated with carbonated polystyrene for
electroluminescence detection. This composite structure shows a weak
ultraviolet electroluminescence band at 395 nm and a yellow
electroluminescence band. These data prove that surface modification
which blocks the transverse movement of carriers between neighbouring
nanorods plays important roles in the ultraviolet emission of ZnO
nanorods. These findings are vital for future display device design.

8000 CROSSDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY

Ryde and Petrosian have pointed out that the rise phases of
gamma-ray burst (GRB) pulses originate from the widths of the
intrinsic pulses and their decay phases are determined by the
curvature effect of the expanding fireball surface based on their
simplified formula. In this paper we investigate in detail the issue
based on the formula in Ref.[20], which is derived based on a model
of highly symmetric expanding fireballs, where the Doppler effect is
the key factor to be concerned about, and no terms are omitted in
their derivation. Our analyses show that the decay phases of the
observed pulses originate from the contributions from both the
curvature effect of the expanding fireball and the two timescales of
the local pulses, and the rise phases of the observed pulses only
come from the two timescales of the local pulses. Associated with a
local pulse with both rise and decay portions, the light curve of
GRBs in the rise portion is expected to undergo a concave phase and
then a convex one, whereas that in the decay portion is expected to
evolve by an opposite process. And the ratio of the concave timescale
to the convex one in the rise phase of the observed pulse linearly
increases with the ratio of the rising timescale to the decay one of
the local pulse ($r_{\rm rd}$), whereas the ratio of the convex
timescale to the concave timescale in its decay phase linearly
decreases with $r_{\rm rd}$. The two correlations are independent of
the local pulse forms and the rest-frame radiation forms. But the
different forms of local pulses and the different values of $r_{\rm
rd}$ gives rise to the diversity of the light curve pulse shapes. We
test a sample of 86 GRB pulses detected by the BATSE instrument on
board the Compton Gamma Ray Observatory and find that the
characteristics do exist in the light curve of GRBs.

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