In this paper, we obtain a supersymmetric generalization for the
classical Boussinesq equation. We show that the supersymmetric
equation system passes the Painlev\'{e test and we also calculate
its one- and two-soliton solutions.

This paper investigates structure equation and Mei conserved quantity
of Mei symmetry of Appell equations for non-Chetaev nonholonomic
systems. Appell equations and differential equations of motion for
non-Chetaev nonholonomic mechanical systems are established. A new
expression of the total derivative of the function with respect to
time $t$ along the trajectory of a curve of the system is obtained,
the definition and the criterion of Mei symmetry of Appell equations
under the infinitesimal transformations of groups are also given. The
expressions of the structure equation and the Mei conserved quantity
of Mei symmetry in the Appell function are obtained. An example is
given to illustrate the application of the results.

In this paper the new continuum traffic flow model proposed by Jiang
{\it et al is developed based on an improved car-following model, in
which the speed gradient term replaces the density gradient term in
the equation of motion. It overcomes the wrong-way travel which
exists in many high-order continuum models. Based on the continuum
version of car-following model, the condition for stable traffic flow
is derived. Nonlinear analysis shows that the density fluctuation in
traffic flow induces a variety of density waves. Near the onset of
instability, a small disturbance could lead to solitons determined by
the Korteweg--de-Vries (KdV) equation, and the soliton solution is
derived.

We present a scheme for probabilistic remote preparation of an
entangled two-qubit state with three parties from a sender to either
of two receivers. The quantum channel is composed of a partially
entangled two-qubit state and a partially entangled three-qubit
state. We calculate the successful total probabilities of the scheme
in general and particular cases, respectively. We also calculate
total classical communication cost in a general case and two
particular cases, respectively.

This paper reports that a quantum dense coding can be implemented
with ions confined in a linear trap and interacting with laser
beams. The scheme is insensitive to the interaction between the
quantum channel and the environment. The Bell-state measurement is
not involved and the probability of success in our scheme is $1.0$.

In this paper, we investigate the behaviour of the geometric phase
of a more generalized nonlinear system composed of an effective
two-level system interacting with a single-mode quantized cavity
field. Both the field nonlinearity and the atom--field coupling
nonlinearity are considered. We find that the geometric phase
depends on whether the index $k$ is an odd number or an even number
in the resonant case.
In addition, we also find that the geometric phase may
be easily observed when the field nonlinearity is not considered.
The fractional statistical phenomenon appears in
this system if the strong nonlinear atom--field coupling is
considered. We have also investigated the geometric phase of an
effective two-level system interacting with a two-mode quantized
cavity field.

A potential scheme is proposed for generating cluster states of many
atoms in cavity quantum electradynamics (QED), in which an unorthodox
encoding is employed with the ground state being qubit $\left\vert
0\right\rangle $ while two closely spaced upper states being qubit
$\left\vert 1\right\rangle $. Throughout the scheme the cavities can
be in thermal states but are only virtually excited. We show how to
create the cluster states by performing a two-step but no
single-qubit operation. Discussion is also carried out on the
experimental feasibility of our scheme.

The existence of decoherence-free subspace (DFS) has been discussed
widely. In this paper, we propose an alternative scheme for
generating the four-atom $W$ states by manipulating DF qubits. The
atoms are divided into two pairs and trapped in two separate optical
cavities. Manipulation of atoms within DFS may generate a two-atom
maximally entangled state in an individual cavity, which is a stable
state. After driving the system out of DFS, the atoms will interact
resonantly with the cavity field. The photons leaking from the
cavities interfere at the beamsplitter, which destroys which-path
information, and are finally detected by one of the detectors,
leading to the generation of a $W$ state. In addition, the numerical
simulation indicates that the fidelity of the prepared state can, for
a very wide parameter regime, be very close to unity.

This paper proposes an experimentally feasible scheme for
teleportation of an unknown two-atom entangled state, where a
cluster state is used as the quantum channel. This scheme does not
need any joint measurement. In addition, the successful probability
and fidelity of teleportation can both reach 1.0. The current scheme
can be realized within the current experimental technology.

Inspired by a recent paper [2002 {\it J. Opt. B {\bf 4 316] we
present an alternative scheme to teleport an entanglement of zero-
and one-photon states of a running-wave field. The scheme employs
only linear optical elements plus single-photon sources and
detectors.

This paper proposes schemes for generating multiple-photon and
multiple-atom cluster states, respectively. The schemes are based on
the cavity input--output process and atomic or photonic states
measurement, and the successful probabilities approach unity in the
ideal case. The numerical simulations show that the produced
multiple-particle cluster states have high fidelity even if the
Lamb--Dicke condition is not satisfied. Some practical imperfections,
such as atomic spontaneous emission and output coupling inefficiency,
only decrease the success probability but exert no influence on the
fidelity of generated multiple-particle cluster states. From the
experimental point of view, smaller operation number and lack of need
for individual addressing keeps the schemes easy to implement. These
schemes may offer a promising approach to the generation of a
large-scale cluster state.

New unification theories predict large extra dimensions (LEDs). If
that is the case, gravity would be stronger at short ranges than what
Newtonian gravity predicts. LEDs could also have effects at atomic
level. In this paper we propose a new method to constrain the size of
`gravity-only' LEDs by analysing how these LEDs modify the energy of
the atomic transitions 1s--2s and 2s--2p (Lamb shift), in the
particular case of the hydrogen and muonium atoms. We estimate these
effects by using Bethe's non-relativistic treatment of Lamb shift. In
the particular case of three LEDs, which may be a candidate to
explain the interaction mechanism of dark matter particles, we have
found that current knowledge in atomic spectroscopy could constrain
their sizes to less than 10\,$\mu$m. Although our contributions do
not reach the sensitivity given by SN1987a, they are still slightly
better than recent constraints given by Inverse Square Law tests of
the E\"{o}t--Wash group at Washington University, which gave $R_{3}
< 36.6\,\mu$m.

This paper studies the effects of cross-correlations between the
real and imaginary parts of quantum noise on the laser intensity in
a saturation laser model. It derives the analytic expressions of the
intensity correlation function ${C(\tau)}$ and the associated
relaxation time ${T({C})}$ in the case of a stable locked phase
resulting from the cross-correlation ${\lambda_q}$ between the real
and imaginary parts of quantum noise. Based on numerical
computations it finds that the presence of cross correlations
between the real and imaginary parts of quantum noise slow down the
decay of intensity fluctuation, i.e., it causes the increase of
intensity fluctuation.

In this paper, based on the invariance principle of differential
equations, we propose a simple adaptive control method to
synchronize the network with coupling of the general form. Comparing
with other control approaches, this scheme only depends on each
node's state output. So we need not to know the concrete network
structure and the solutions of the isolate nodes of the network in
advance. In order to demonstrate the effectiveness of the method, a
special example is provided and numerical simulations are performed.
The numerical results show that our control scheme is very effective
and robust against the weak noise.

In this paper, the synchronization of a unified chaotic system is
investigated by the use of output feedback controllers; a two-input
single-output feedback controller and single-input single-output
feedback controller are presented to synchronize the unified chaotic
system when the states are not all measurable. Compared with the
existing results, the controllers designed in this paper have some
advantages such as small feedback gain, simple structure and less
conservation. Finally, numerical simulations results are provided to
demonstrate the validity and effectiveness of the proposed method.

The performance of synchronous reluctance motor (SynRM) degrades due
to chaos when its systemic parameters fall into a certain area. To
control the undesirable chaos in SynRM, a passive control law is
presented in this paper, which transforms the chaotic SynRM into an
equivalent passive system. It is proved that the equivalent system
can be asymptotically stabilized at the set equilibrium point,
namely, chaos in SynRM can be controlled. Moreover, in order to
eliminate the influence of undeterministic parameters, an adaptive
law is introduced into the designed controller. Computer simulation
results show that the proposed controller is very effective and
robust against the uncertainties in systemic parameters. The present
study may help to maintain the secure operation of industrial servo
drive system.

This paper investigates the function cascade synchronization of
chaos system. Combining cascade synchronization scheme, parametric
adaptive control and projective synchronization scheme, it proposes
a new function cascade synchronization scheme to address a
generalized-type synchronization problem of three famous chaotic
systems: the Lorenz system, Liu system and R\"{o}ssler system, the
states of two identical chaotic systems with unknown parameters can
be asymptotically synchronized by choosing different special
suitable error functions. Numerical simulations are used to verify
the effectiveness of the proposed synchronization techniques.

Interaction between transmission control protocol (TCP) and random
early detection (RED) gateway in the Internet congestion control
system has been modelled as a discrete-time dynamic system which
exhibits complex bifurcating and chaotic behaviours. In this paper, a
hybrid control strategy using both state feedback and parameter
perturbation is employed to control the bifurcation and stabilize the
chaotic orbits embedded in this discrete-time dynamic system of
TCP/RED. Theoretical analysis and numerical simulations show that the
bifurcation is delayed and the chaotic orbits are stabilized to a
fixed point, which reliably achieves a stable average queue size in
an extended range of parameters and even completely eliminates the
chaotic behaviour in a particular range of parameters. Therefore it
is possible to decrease the sensitivity of RED to parameters. By
using the hybrid strategy, we may improve the stability and
performance of TCP/RED congestion control system significantly.

The resistively--capacitively--inductively-shunted (RCL-shunted)
Josephson junction (RCLSJJ) shows chaotic behaviour under some
parameter conditions. Here a scheme for controlling chaos in the
RCLSJJ is presented based on the linear feedback theory. Numerical
simulations show that this scheme can be effectively used to control
chaotic states in this junction into stable periodic states.
Moreover, the different stable period states with different period
numbers can be obtained by appropriately adjusting the feedback
intensity and delay time without any pre-knowledge of this system
required.

This paper demonstrates and analyses double heteroclinic tangency in
a three-well potential model, which can produce three new types of
bifurcations of basin boundaries including from smooth to Wada basin
boundaries, from fractal to Wada basin boundaries in which no
changes of accessible periodic orbits happen, and from Wada to Wada
basin boundaries. In a model of mechanical oscillator, it shows that
a Wada basin boundary can be smooth.

The dynamics of discrete time delayed Hopfield neural networks is
investigated. By using a difference inequality combining with the
linear matrix inequality, a sufficient condition ensuring global
exponential stability of the unique equilibrium point of the
networks is found. The result obtained holds not only for constant
delay but also for time-varying delays.

In this paper, we report the dynamical behaviours of a
four-dimensional autonomous continuous dissipative system analysed
when the parameter is varied in the range we are interested in. The
system changes its dynamical modes between periodic motion and
quasiperiodic motion. Furthermore, the existence of two-torus is
investigated numerically by means of Lyapunov exponents. By taking
advantage of phase portraits and Poincar\'{e} sections, two types of
the two-torus are observed and proved to have the structure of ring
torus and horn torus, both of which are known to be the standard
tori.

Based on the Routh--Hurwitz criterion, this paper investigates the
stability of a new chaotic system. State feedback controllers are
designed to control the chaotic system to the unsteady equilibrium
points and limit cycle. Theoretical analyses give the range of value
of control parameters to stabilize the unsteady equilibrium points of
the chaotic system and its critical parameter for generating Hopf
bifurcation. Certain nP periodic orbits can be stabilized by
parameter adjustment. Numerical simulations indicate that the method
can effectively guide the system trajectories to unsteady equilibrium
points and periodic orbits.

Single-wavelength anomalous diffraction (SAD) phasing is
increasingly important in solving de novo protein structures.
Direct methods have been proved very efficient in SAD phasing. This
paper aims at probing the low-resolution limit of direct-method SAD
phasing. Two known proteins TT0570 and Tom70p were used as test
samples. Sulfur-SAD data of the protein TT0570 were collected with
conventional Cu-K\alpha source at 0.18nm resolution. Its
truncated subsets respectively at 0.21, 0.30, 0.35 and 0.40nm
resolutions were used in the test. TT0570 Cu-K$\alpha$ sulfur-SAD
data have an expected Bijvoet ratio <\vert\Delta F\vert>/\ \sim
0.55%. In the 0.21nm case, a single run of OASIS-DM-ARP/wARP
led automatically to a model containing 1178 of the total 1206
residues all docked into the sequence. In 0.30 and 0.35nm cases,
SAD phasing by OASIS-DM led to traceable electron density maps. In
the 0.40nm case, SAD phasing by OASIS-DM resulted in a degraded
electron density map, which may be difficult to trace but still
contains useful secondary-structure information. Test on real
0.33nm selenium-SAD data of the protein Tom70p showed that even
automatic model building was not successful, the combination of
manual tracing and direct-method fragment extension was capable of
significantly improving the electron-density map. This provides the
possibility of effectively improving the manually built model before
structure refinement is performed.

The B-spline basis set plus complex scaling method is applied to the
numerical calculation of the exact resonance parameters $E_r}$
and $\Ga/2$ of a hydrogen atom in parallel electric and magnetic
fields. The method can calculate the ground and higher excited
resonances accurately and efficiently. The resonance parameters with
accuracies of $10^{-9}-10^{-12}$ for hydrogen atom in parallel
fields with different field strengths and symmetries are presented
and compared with previous ones. Extension to the calculation of
Rydberg atom in crossed electric and magnetic fields and of atomic
double excited states in external electric fields is discussed.

Charge state distribution of 0.8MeV/u uranium ions after
transmission through a thin carbon foil has been studied. It is
observed that the charge state distribution is equilibrated after
the uranium ions have passed through a 15 $\mu $g/cm$^{2}$ carbon
foil. The equilibrated average charge state is 33.72 and the charge
equilibration time of uranium ions in carbon foil is less than
5.4fs.

The phenomena of super energy flows are studied theoretically and
numerically in a parallel-plate waveguide which is filled with two
layered equally-thick different media, i.e. air and specific
left-handed materials (LHM) with $\epsilon_{{\rm
r}1}=-1/(1+\delta)+\i\gamma$ and $\mu_{{\rm
r}1}=-(1+\delta)+\i\gamma$. In this special waveguide,
two-directional super-energy flows are excited by a three-dimensional
horizontal electric dipole at the same time, which has transmission
patterns different from those of two-dimensional source and
three-dimensional vertical electric dipole. We also show that the
retardation and loss in LHM are sensitive to the amplitude of super
power densities, and the dimensions of waveguide determine the
propagating modes, which makes super energy flows more practical.

This paper extends the definition of fractional Fourier transform
(FRFT) proposed by Namias V by using other orthonormal bases for
$L^{2}\left( R \right)$ instead of Hermite--Gaussian functions. The
new orthonormal basis is gained indirectly from multiresolution
analysis and orthonormal wavelets. The so defined FRFT is called
wavelets-fractional Fourier transform.

We propose a scheme for the implementation of remote controlled-NOT
gates and entanglement swapping via geometric phase gates in
ion-trap systems. The proposed scheme uses the two ground states of
the $\Lambda$-type ions as memory instead of the vibrational mode.
And the system is robust against the spontaneous radiation and the
dephasing.

Considering a system in which a single photon and a coherent field
propagate through a Kerr medium, when the weak cross-Kerr
interaction between the coherent state and the single photon under
decoherence is involved, this paper derives analytically a
macroscopic superposition state by the superoperator method and
investigates the influences of decoherence on the coherence
properties of the obtained state. It finds that the macroscopic
superposition state will experience evolution from a pure
superposition state to a mixed state in a dissipative environment
and the Kerr effect makes the field display a periodic revival from
decoherence for a short time.

In this paper, we propose a physical scheme to realize quantum SWAP
gate by using a large-detuned single-mode cavity field and two
identical Rydberg atoms. It is shown that the scheme can also be used
to create multi-atom cluster state. During the interaction between
atom and cavity, the cavity is only virtually excited and thus the
scheme is insensitive to the cavity field states and cavity decay.
With the help of our scheme it is very simple to prepare the $N$-atom
cluster state with perfect fidelity and probability. The practical
feasibility of this method is also discussed.

We present a theory for quantum interference of four photons
generated by spontaneous parametric down-conversion. Detailed
investigation of the dependence of fourfold coincidence count rate
on time delay between the incident and the reflective pump laser
pulses is carried out. Gaussian type dependence is found, and good
agreement between our theoretical results and experimental data
reported in the literature is achieved.

In this paper, the compositions in a laser absorption region can be
determined from the experiment of laser impulse coupling. When the
ambient pressure varies from 9325 to 33325Pa, the compositions are
vapour and plasma; while from 35325 to 101325Pa, they are ambient air
and plasma. By analysing the relation between the degree of
compression and the ambient pressure, the compositions can be
determined and the variation of plasma can be explained.

This paper theoretically studies the double-pumped fibre-optical
parametric amplifiers (FOPAs) in photonic crystal fibres. Two
distinct working regimes of FOPAs are researched, which depend on the
dispersion at the central wavelength of the two pumps. Extremely
broad tuning range can be obtained when the central pump wavelength
is in the normal dispersion regime and is insensitive to the
wavelength separation between the two pumps, while the tuning range
is narrow in the anomalous dispersion regime and can be significantly
enhanced by increasing the wavelength separation. Impacts of
higher-order dispersions and temporal walk-off on the gain spectra
are also discussed.

This paper reports a continuous-wave (CW) mid-infrared intracavity
singly resonant optical parametric oscillator based on periodically
poled lithium niobate (PPLN) pumped by a diode-end-pumped CW
Nd:YVO$_{4}$ laser. Considering the thermal lens effects, it adopted
an optical ballast lens and the near-concentric cavity for better
operation. At the PPLN's grating period of 28.5\,$\mu$m and the
temperature of 140\du, the maximum idler output power of 155\,mW at
3.86\,$\mu$m has been achieved when the 808\,nm pump power is
8.5\,W, leading to an optical-to-optical conversion efficiency of
1.82{\%}.

By employing a simple model of describing three-level lasers, we have
theoretically investigated the effect of photon lifetime on the
output dynamics of Er-doped distributed feedback fibre lasers. And
based on the theoretical analysis we have proposed a promising method
to suppress self-pulsing behaviour in the fibre lasers.

The green and red up-conversion emissions centred at about 534, 549
and 663\,nm of wavelength, corresponding respectively to the
${^{2}}H_{11 / 2} \to {^{4}}I_{15 / 2}$, ${^{4}}S_{3 / 2} \to
{^{4}}I_{15 / 2}$ and ${^{4}}F_{9 / 2} \to {^{4}}I_{15 / 2}$
transitions of Er$^{3 + }$ ions, have been observed for the Er$^{3 +
}$-doped silicate glass excited by a 978\,nm semiconductor laser
beam. Excitation power dependent behaviour of the up-conversion
emission intensity indicates that a two-photon absorption
up-conversion process is responsible for the green and red
up-conversion emissions. The temperature dependence of the green
up-conversion emissions is also studied in a temperature range of
296--673\,K, which shows that Er$^{3 + }$-doped silicate glass can
be used as a sensor in high-temperature measurement.

This paper reports that a two-dimensional single-defect photonic
crystal waveguide in the \textit{$\Ga$-K} direction with triangular
lattice on a silicon-on-insulator substrate is fabricated by the
combination of electron beam lithography and inductively coupled
plasma etching. A ministop band (MSB) is observed by the measurement
of transmission characteristics. It results from the coupling
between the two modes with the same symmetry, which is analysed from
the stimulated band diagram by the effective index and the
two-dimensional plane wave expansion methods. The parameter working
on the MSB is the ratio of the radius of air holes to the lattice
constant, $r/a$. It is obtained that the critical $r/a$ value
determining the occurrence or disappearance of MSB is 0.36. When
$r/a $ is larger than or equal to 0.36, the MSB occurs. However,
when $r/a $ is smaller than 0.36, the MSB disappears.

A simple model for approximate bandgap structure calculation of
all-solid photonic bandgap fibre based on an array of rings is
proposed. In this model calculated are only the potential modes of a
unit cell, which is a high-index ring in the low-index background for
this fibre, rather than the whole cladding periodic structure based
on Bloch's theorem to find the bandgap. Its accuracy is proved by
comparing its results with the results obtained by using the accurate
full-vector plane-wave method. High speed in computation is its great
advantage over the other exact methods, because it only needs to find
the roots of one-dimensional analytical expressions. And the results
of this model, mode plots, offer an ideal environment to explore the
basic properties of photonic bandgap clearly.

The central problem of the lattice Boltzmann method (LBM) is to
construct a discrete equilibrium. In this paper, a multi-speed 1D
cell-model of Boltzmann equation is proposed, in which the
cell-population equilibrium, a direct non-negative approximation to
the continuous Maxwellian distribution, plays an important part. By
applying the explicit one-order Chapman--Enskog distribution, the
model reduces the transportation and collision, two basic evolution
steps in LBM, to the transportation of the non-equilibrium
distribution. Furthermore, 1D dam-break problem is performed and the
numerical results agree well with the analytic solutions.

Frequency shifts of the acetylene saturated absorption lines at
1.5\,$\mu$m with temperature, gas pressure and laser power have been
investigated in detail. The second-order Doppler effect, the recoil
effect, the Zeeman effect, the pressure shift and the power shift
are taken into consideration. The magnitudes of those shifts caused
by various effects are evaluated. In order to reproduce the
stability of $5.7\times10^{ - 14}$ obtained by Edwards, all
necessary conditions are given. The results show that when there is
a larger external magnetic field, the Zeeman shift could not be
neglected, so that the shield should be employed. And the design of
a long cavity is advantageous to reduce the influence of the
second-order Doppler effect. The results also show that at least
$\pm $2.5\du\ temperature control for cavity can effectively prevent
several effects and improve the frequency stability.

The total internal partition sums were calculated in the product
approximation at temperatures up to 5000\,K for the asymptotic
asymmetric-top HO$_{2}$ molecule. The calculations of the rotational
partition function and the vibrational partition function were
carried out with the rigid-top model and in the harmonic oscillator
approximation, respectively. Our values of the total internal
partition sums are consistent with the data of HITRAN database with
$-$0.14{\%} at 296\,K. Using the calculated partition functions, we
have calculated the line intensities of $\nu _{2}$ band of HO$_{2}$
at several high temperatures. The results showed that the calculated
line intensities are in very good agreement with those of HITRAN
database at temperatures up to 3000\,K, which provides a strong
support for the calculations of partition functions and line
intensities at high temperatures. Then we have extended the
calculation to higher temperatures. The simulated spectra of
$\nu_{2}$ band of the asymptotic asymmetric-top HO$_{2}$ molecule at
4000 and 5000\,K are also obtained.

CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES

It has been confirmed that glass-forming ability (GFA) of
supercooled liquids is related to not only liquid phase stability
but also the crystallization resistance. In this paper, it is found
that the liquid region interval ($T_{\rm l}-T_{\rm g})$
characterized by the normalized parameter of $T_{\rm g}$/$T_{\rm l}$
could reflect the stability of glass-forming liquids at the
equilibrium state, whilst the normalization of supercooled liquid
region $\Delta T_{\rm x}$=($T_{\rm x}-T_{\rm g})$, i.e. $\Delta
T_{\rm x}$/$T_{\rm x}$ (wherein $T_{\rm l}$ is the liquidus
temperature, $T_{\rm g}$ the glass transition temperature, and
$T_{\rm x}$ the onset crystallization temperature) could indicate
the crystallization resistance during glass formation. Thus, a new
parameter, defined as $\xi =T_{\rm g}$/$T_{\rm l}+\Delta T_{\rm
x}$/$T_{\rm x}$ is established to predict the GFA of supercooled
liquids. In comparison with other commonly used criteria, this
parameter demonstrates a better statistical correlation with the GFA
for various glass-forming systems including metallic glasses, oxide
glasses and cryoprotectants.

Temperature dependence of ratio between dielectric anisotropy and
order parameter of fluorinated nematic liquid crystal is
investigated by using a semi-empirical molecular orbital package
that can accurately calculate an angle between molecular dipole
moment and long axis. We optimize the molecular conformations with
three semi-empirical Hamiltonians AM1, PM3 and PM5, and then make a
comparison between computational results and experimental
measurements. It is shown that the results obtained from AM1 method
are in good agreement with the measurements. The present study
offers an applicable method to predict the dielectric properties of
liquid crystal material.

The formation and mechanical properties of amorphous copper are
studied using molecular dynamics simulation. The simulations of
tension and shearing show that more pronounced plasticity is found
under shearing, compared to tension. Apparent strain hardening and
strain rate effect are observed. Interestingly, the variations of
number density of atoms during deformation indicate free volume
creation, especially under higher strain rate. In particular, it is
found that shear induced dilatation does appear in the amorphous
metal.

Asymmetric plate impact experiments are conducted on LY12 aluminium
alloy in a pressure range of 85--131\,GPa. The longitudinal sound
speeds are obtained from the time-resolved particle speed profiles of
the specimen measured with Velocity Interferometer System for Any
Reflector (VISAR) technique, and they are shown to be good agreement
with our previously reported data of this alloy in a pressure range
of 20--70\,GPa, and also with those of 2024 aluminium reported by
McQueen. Using all of the longitudinal speeds and the corresponding
bulk speeds calculated from the Gruneisen equation of state (EOS),
shear moduli of LY12 aluminium alloy are obtained. A comparison of
the shear moduli in the solid phase region with those estimated from
the Steinberg model demonstrate that the latter are systematically
lower than the measurements. By re-analysing the pressure effect on
the shear modulus, a modified equation is proposed, in which the
pressure term of $P/\eta^{1/3}$ in the Steinberg model is replaced by
a linear term. Good agreement between experiments and the modified
equation is obtained, which implies that the shear modulus of LY12
aluminium varies linearly both with pressure and with temperature
throughout the whole solid phase region. On the other hand, shear
modulus of aluminium in a solid-liquid mixed phrase region decreases
gradually and smoothly, a feature that is very different from the
drastic dropping at the melting point under static conditions.

Our lattice dynamics simulation of Xe-hydrate with four-site TIP4P
oxygen-shell model can accurately reproduce each peak position in
the inelastic incoherent neutron scattering spectrum at the acoustic
band (below 15\,meV) and yield correct relative intensity. Based on
the results, the uncertain profile at $\sim $6\,meV is assigned to
anharmonic guest modes coupled strongly to small cages. Blue shift
is proposed in phonon dispersion sheet in the case of anticrossing
and found to be an evident signal for guest--host coupling that
explains the anomalous thermal conductivity of clathrate hydrate.

Electronic properties of the (001) surface of cubic BaZrO$_{3}$ with
BaO and ZrO$_{2}$ terminations have been studied using
first-principles calculations. Surface structure, partial density of
states, band structure and surface energy have been obtained. We
find that the largest relaxation appears in the first layer of
atoms, and the relaxation of the BaO-terminated surface is larger
than that of the ZrO$_{2}$-terminated surface. The surface rumpling
of the BaO-terminated surface is also larger than that of the
ZrO$_{2}$-terminated surface. Results of surface energy calculations
reveal that the BaZrO$_{3}$ surface is likely to be more stable than
the PbZrO$_{3}$ surface.

A comprehensive understanding of the organic semiconductor material
pentacene is meaningful for organic field-effect transistors (OFETs).
Thin films of pentacene are the most mobile molecular films known to
date. This paper reported that the pentacene sample was successfully
synthesized. The purity of pentacene is up to 95\%. The results of a
joint experimental investigation based on a combination of infrared
absorption spectra, mass spectra (MS), element analysis, x-ray
diffraction (XRD) and atom force microscopy (AFM). The authors
fabricated OFET with the synthesized pentacene. Its field effect
mobility is about 1.23\,cm$^2$/(V$\cdot$s) and on--off ratio is above
10$^{6}$.

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

In this paper the growth mechanism of a Te/Bi$_{2}$Te$_{3}$ novel
structure is studied by \textit{ab-initio} calculations. The results
show that the growth of Te nanorods is determined by the adsorption
energy of Te atoms on different crystalline Te surfaces. The
adsorption energy of Te on the Te (001) surface is 3.29 eV, which is
about 0.25 eV higher than that of Te on the Te (110). This energy
difference makes the preferential growth direction along the $<001>$
direction. In addition, the higher surface energy of
Bi$_{2}$Te$_{3}$ (110) and the lattice misfit between crystalline
Bi$_{2}$Te$_{3}$ and Te along $<001>$ direction are considered to
explain the growth of the Bi$_{2}$Te$_{3}$ nanoplatelets, in which
Volmer--Weber model is used. The theoretical results are in
agreement with experimental observation.

This paper presents calculating results of the two-dimensional
electron gas (2DEG) distributions in AlGaN/GaN material system by
solving the Schr\"{o}dinger and Poisson equations self-consistently.
Due to high 2DEG density in the AlGaN/GaN heterojunction interface,
the exchange correlation potential should be considered among the
potential energy item of Schr\"{o}dinger equation. Analysis of the
exchange correlation potential is given. The dependencies of the
conduction band edge, 2DEG density on the Al mole fraction are
presented. The polarization fields have strong influence on 2DEG
density in the AlGaN/GaN heterojunction, so the dependency of the
conduction band edge on the polarization is also given.

We investigate the spin-flip process through double quantum dots
coupled to two half-metallic ferromagnetic leads in series. By means
of the slave-boson mean-field approximation, we calculate the
density of states in the Kondo regime for two different
configurations of the leads. It is found that the transport shows
some remarkable properties depending on the spin-flip strength.
These effects may be useful in exploiting the role of electronic
correlation in spintronics.

Intensive blue photoluminescence (PL) was observed at room
temperature from the nanocrystalline-Si/SiO$_{2}$ (nc-Si/SiO$_{2})$
multilayers (MLs) obtained by thermal annealing of
SiO/SiO$_{2}$\,MLs for the first time. By controlling the size of
nc-Si formed in SiO sublayer from 3.5 to 1.5 nm, the PL peak
blueshifts from 457 to 411 nm. Combining the analysis of TEM, Raman
and absorption measurement, this paper attributes the blue PL to
multiple luminescent centres at the interface of nc-Si and
SiO$_{2}$.

The scalability of the tunnel-regenerated multi-active-region
(TRMAR) structure has been investigated for the application in
light-emitting diodes (LEDs). The use of the TRMAR structure was
proved theoretically to have unique advantages over conventional
single-active-layer structures in virtually every aspect, such as
high quantum efficiency, high power and low leakage. Our study
showed that the TRMAR LED structure could obtain high output power
under low current injection and high wall-plug efficiency compared
with the conventional single-active-layer LED structure.

Based on the results of explicit forms of free energy density for
each possible arrangement of magnetization fluxes in large-scale
two-dimensional (2D) square $\pi $-loop arrays given by Li
\textit{et al} [2007 {\em Chin. Phys.} {\bf 16} 1450], the
field-cooled superconducting phase transition is further
investigated by analysing the free energy of the arrays with a
simplified symmetrical model. Our analytical result is exactly the
same as that obtained in Li's paper by means of numerical
calculations. It is shown that the phase transition splits into two
branches with either ferromagnetic or anti-ferromagnetic flux
ordering, which depends periodically on the strength of external
magnetic flux $\phi_{\e}$ through each loop and monotonically on the
screen parameter $\beta $ of the loops in the arrays. In principle,
the diagram of the phase branches is similar to that of its
one-dimensional counterpart. The influence of thermal fluctuation on
the flux ordering during the transition from normal to
superconducting states of the $\pi $-loop arrays is also discussed.

By using a sol-gel clue, a set of polycrystalline perovskite samples
La$_{1 - x}$Ag$_{x}$MnO$_{3}$ with a nominal doping level $x$ ranging
from 0.05 to 0.45 has been synthesized. The chemical composition and
the magnetism of the samples were investigated. A little Ag was found
seeping from the samples in the sintering process when the doping
level exceeded 0.05 and the sintering temperature was higher than
700\du\, resulting in the samples being in multiphase. The magnetic
transition points of the samples have been found to decrease with
increasing sintering temperature. A concentration-dependent $T_{\rm
c}$ similar to that of bivalent metal ion doped perovskite, has been
obtained. We believe that the Ag seeping in the sintering process is
responsible for those magnetic characteristics.

We develop a modified two-step method of growing high-density and
narrow size-distribution InAs/GaAs quantum dots (QDs) by molecular
beam epitaxy. In the first step, high-density small InAs QDs are
formed by optimizing the continuous deposition amount. In the second
step, deposition is carried out with a long growth interruption for
every 0.1 InAs monolayer. Atomic force microscope images show that
the high-density ($\sim $5.9$\times $10$^{10}$\,cm$^{ - 2})$ good
size-uniformity InAs QDs are achieved. The strong intensity and
narrow linewidth (27.7\,meV) of the photoluminescence spectrum show
that the QDs grown in this two-step method have a good optical
quality.

Lidar (Light detection and ranging) has special capabilities for
remote sensing of many different behaviours of the atmosphere. One
of the techniques which show a great deal of promise for several
applications is Raman scattering. The detecting capability,
including maximum operation range and minimum detectable gas
concentration is one of the most significant parameters for lidar
remote sensing of pollutants. In this paper, based on the new method
for evaluating the capabilities of a Raman lidar system, we present
an evaluation of detecting capability of Raman lidar for monitoring
atmospheric CO$_{2}$ in Hefei. Numerical simulations about the
influence of atmospheric conditions on lidar detecting capability
were carried out, and a conclusion can be drawn that the maximum
difference of the operation ranges caused by the weather conditions
alone can reach about 0.4 to 0.5km with a measuring precision within
30ppmv. The range of minimum detectable concentration caused by the
weather conditions alone can reach about 20 to 35 ppmv in vertical
direction for 20000 shots at a distance of 1 km on the assumption
that other parameters are kept constant. The other corresponding
parameters under different conditions are also given. The capability
of Raman lidar operated in vertical direction was found to be
superior to that operated in horizontal direction. During practical
measurement with the Raman lidar whose hardware components were
fixed, aerosol scattering extinction effect would be a significant
factor that influenced the capability of Raman lidar. This work may
be a valuable reference for lidar system designing, measurement
accuracy improving and data processing.

This paper deals with the coverage analysis problem of elliptical
orbits. An algorithm based on ergodic theory, for long-term coverage
of elliptical orbits, is proposed. The differential form of the
invariant measure is constructed via the perturbation on mean
orbital elements resulted from the $J_{2}$ term of non-spherical
shape of the earth. A rigorous proof for this is then given.
Different from the case of circular orbits, here the flow and its
space of the dynamical system are defined on a physical space, and
the real-value function is defined as the characteristic function on
station mask. Therefore, the long-term coverage is reduced to a
double integral via Birkhoff--Khinchin theorem. The numerical
implementation indicates that the ergodic algorithm developed is
available for a wide range of eccentricities.

Investigations of low energy transfer trajectories are important for
both celestial mechanics and astronautics. Methodologies using the
theories from dynamical systems are developed in recent years. This
paper investigates the dynamics of the earth--moon system. Low
energy transfer trajectories are solved numerically by employing a
hybrid strategy: first, a genetic hide and seek method performs a
search in large domain to confine the global minimum $f({\eta})$
(objective function) region; then, a deterministic Nelder--Mead
method is utilized to refine the minimum quickly. Some transfer
trajectories of the spacecraft in the earth--moon system are
successfully simulated which verify the desired efficiency and
robustness of the method of this paper.

In this paper, the propagation of x-ray bursts
in the magnetoplasma of pulsar magnetosphere is discussed. The electromagnetic
interaction between x-ray bursts and magnetoplasma is described as some geometry.
The electromagnetic effects of surface superstrong magnetic
field and dynamic effects of outflowing magnetoplasma of pulsars are
treated as an optical metric. The Gordon metric is introduced to
represent the gravitational metric and optical metric. So the
propagation of x-ray bursts in magnetoplasma of pulsars can be
described as x-ray bursts transmitting in an effective space
characterized by Gordon metric. The modification of gravitational
redshift, attributed to the flowing magnetoplasma of pulsars, is
obtained and it is shown that the modification is of redshift and can
reach the same magnitude as the gravitational redshift for ordinary
pulsars.