This paper studies conformal invariance and conserved quantities of
Hamilton system. The definition and the determining equation of
conformal invariance for Hamilton system are provided. The
relationship between the conformal invariance and the Lie symmetry
are discussed, and the necessary and sufficient condition that the
conformal invariance would be the Lie symmetry of the system under
the infinitesimal one-parameter transformation group is deduced. It
gives the conserved quantities of the system and an example for
illustration.

Based on the weak Noether symmetry proposed by Mei F X, this paper
discusses the weak Noether symmetry for nonholonomic system of
non-Chetaev type, and presents expressions of three kinds of
conserved quantities by weak Noether symmetry. Finally, the
application of this new results is showed by a practical example.

In this paper the conformal invariance by infinitesimal
transformations of first order Lagrange systems is discussed in
detail. The necessary and sufficient conditions of conformal
invariance and Lie symmetry simultaneously by the action of
infinitesimal transformations are given. Then it gets the Hojman
conserved quantities of conformal invariance by the infinitesimal
transformations. Finally an example is given to illustrate the
application of the results.

This paper presents a computational fluid dynamics approach for
micro droplet impacting on a flat dry surface. A two-phase flow
approach is employed using FLUENT VOF multiphase model to calculate
the flow distributions upon impact. The contact line velocity is
tracked to calculate the dynamic contact angle through user defined
function program. The study showed that the treatment of contact
line velocity is crucial for the accurate prediction of droplet
impacting on poor wettability surfaces. On the other hand, it has
much less influence on the simulation of droplet impacting on good
wettability surfaces. Good fit between simulation results and
experimental data is obtained using this model.

The quantum secure direct communication (QSDC) protocol with a
random basis and order is analysed and an effective attack, i.e.
teleportation attack, is presented. An eavesdropper can obtain half
of the transmitted secret bits with the help of this special attack.
It is shown that quantum teleportation can be employed to weaken the
role of the order-rearrangement encryption at least in a certain
circumstance. Meanwhile, a possible improvement on this protocol is
proposed, which makes it secure against this kind of attack.

This paper proves that it is impossible to identify orthogonally
time-separated Bell states. If two qubits of a Bell state interact
with the measurement apparatus at different time, any attempt to
identify this state will disturb it.

In this paper, we consider the entanglement dynamics of a four-qubit
model [2006 {\em Phys. Rev.} A \textbf{74} 042328] where two
entangled qubits a and b locally interact with separate
qubits A and B via the spin-exchange-like Hamiltonian. We
study the effect of purity of initial entangled state of qubits
a, b on the entanglement evolution and its relation with energy
transfer. Also, we find that the total bipartite entanglement of
qubits a, b plus A, B is not a constant any longer when the
initial entangled state of a, b is not pure, which is a
complement to the result in the paper [2007 {\em J. Phys.} B
\textbf{40} S45] for the pure case.

This paper proposes a scheme for implementing the teleportation of
an arbitrary unknown two-atom state by using a cluster state of four
identical 2-level atoms as quantum channel in a thermal cavity. The
two distinct advantages of the present scheme are: (i) The
discrimination of 16 orthonormal cluster states in the standard
teleportation protocol is transformed into the discrimination of
single-atom states. Consequently, the discrimination difficulty of
states is degraded. (ii) The scheme is insensitive to the cavity
field state and the cavity decay for the thermal cavity is only
virtually excited when atoms interact with it. Thus, the scheme is
more feasible.

This paper investigates the periodic death and anabiosis of the
entanglement between two moving atoms interacting with the mode
field, and discusses the influences of the atomic motion and the
parameter of the mode field. The results show that, the atomic
motion leads to the periodic death and anabiosis of the entanglement
between two moving atoms, the time of the death and the amplitude of
the anabiosis of the entanglement between two moving atoms depend
on the initial states of two moving atoms and the parameter of the
mode field.

In this paper, the Klein--Gordon equation with the spherical
symmetric Hulth\'{e}n potential is turned into a hypergeometric
equation and is solved in the framework of function analysis
exactly. The corresponding bound state solutions are expressed in
terms of the hypergeometric function, and the energy spectrum of the
bound states is obtained as a solution to a given equation by
boundary constraints.

This paper proposes an alternative scheme for generating four-photon
W state via cavity QED. The scheme bases on the resonant
interaction of a \Lambda -type three level atom with two bimodal cavities. The detection of
atom collapses the cavity to the desired state. Comparing with
previous schemes, the advantage of this scheme is that the
interaction time can be greatly shortened since it uses the resonant
interaction between atom and cavities. Moreover, the proposed scheme
is more experimentally feasible than the previous ones.

The discrete Fourier transform (DFT) is the base of modern signal
processing. 1-dimensional fast Fourier transform (1D FFT) and 2D FFT
have time complexity O(N\log N)$ and O(N^{2}\log N) respectively.
Since 1965, there has been no more essential breakthrough for the design
of fast DFT algorithm. DFT has two properties. One property is that
DFT is energy conservation transform. The other property is that
many DFT coefficients are close to zero. The basic idea of this
paper is that the generalized Grover's iteration can perform the
computation of DFT which acts on the entangled states to search the
big DFT coefficients until these big coefficients contain nearly all
energy. One-dimensional quantum DFT (1D QDFT) and two-dimensional
quantum DFT (2D QDFT) are presented in this paper. The quantum algorithm
for convolution estimation is also presented in this paper. Compared
with FFT, 1D and 2D QDFT have time complexity O(\sqrt{N}) and
$O(N)$ respectively. QDFT and quantum convolution demonstrate that
quantum computation to process classical signal is possible.

This paper investigates the monomer kinetics of polymer dispersed
liquid crystal (PDLC) grating. Fourier transform infrared (FTIR)
spectra are used in the studies of photoreaction kinetics. The
results indicate that there is a relative stable stage arises after
a very short initial stage. Based on FTIR studies, the monomer
diffusion equation is deduced and necessary numerical simulations
are carried out to analyse the monomer conversion which is an
important point to improve phase separation structure of PDLC
grating. Some simulation results have a good agreement with
experimental data. In addition, the effects induced by monomer
diffusion constant $D$ and diffusion--polymerization-ratio rate $R$
are discussed. Results show that monomer conversion can be improved
by increasing value of $D$. Besides, a good equilibrium state
($R=1$) is more beneficial to the diffusion of monomer which is
important in the process of phase separation.

Based on the theoretical results derived from pseudopotential method
and local approximation, this paper studies the thermodynamic
stability of a weakly interacting Fermi gas trapped in a harmonic
potential by using analytical method of thermodynamics. The effects
of the interparticle interactions as well as external potential on
the thermodynamic stability of the system are discussed. It is shown
that the system is stable as for the complete average, but as for
local parts, the system is unstable anywhere. This instability shows
that the stability conditions of mechanics cannot be satisfied
anywhere, and the stability conditions of thermostatics cannot be
satisfied somewhere. In addition, the interactions and external
potential have direct effects on the local stability of the system.

On the assumption that random interruptions in the observation
process are modelled by a sequence of independent Bernoulli random
variables, this paper generalize the extended Kalman filtering
(EKF), the unscented Kalman filtering (UKF) and the Gaussian
particle filtering (GPF) to the case in which there is a positive
probability that the observation in each time consists of noise
alone and does not contain the chaotic signal (These generalized
novel algorithms are referred to as GEKF, GUKF and GGPF
correspondingly in this paper). Using weights and network output of
neural networks to constitute state equation and observation
equation for chaotic time-series prediction to obtain the linear
system state transition equation with continuous update scheme in an
online fashion, and the prediction results of chaotic time series
represented by the predicted observation value, these proposed novel
algorithms are applied to the prediction of Mackey--Glass time-series
with additive and multiplicative noises. Simulation results prove
that the GGPF provides a relatively better prediction performance in
comparison with GEKF and GUKF.

This paper presents the problem of generating four-wing (eight-wing)
chaotic attractors. The adopted method consists in suitably coupling
two (three) identical Lorenz systems. In analogy with the original
Lorenz system, where the two wings of the butterfly attractor are
located around the two equilibria with the unstable pair of
complex-conjugate eigenvalues, this paper shows that the four wings
(eight wings) of these novel attractors are located around the four
(eight) equilibria with two (three) pairs of unstable
complex-conjugate eigenvalues.

This paper proposes a new chaotic system and its fractional-order
chaotic system. The necessary condition for the existence of chaotic
attractors in this new fractional-order system is obtained. It finds
that this new fractional-order system is chaotic for $q>0.783$ if
the system parameter $m$=6. The chaotic attractors for $q$=0.8, and
$q$=0.9 are obtained. A circuit is designed to realize its
fractional-order chaos system for $q$=0.9 by electronic workbench.

Accurate description of magnetization curve has important effect on
ferroresonance. In most of earlier ferroresonance studies the
magnetization curve is modelled as a 3rd or 5th order polynomial.
However, it is not comprehensive. This paper investigates the
chaotic ferroresonance behaviour exhibited by a non-autonomous
circuit which contains a nonlinear flux-controlled inductance. The
ferromagnetic characteristic of this nonlinear inductance
represented by a magnetization curve could be expressed as an $n$th
order two-term polynomial. By varying the value of exponent $n$, the
circuit can assume a diverse range of steady-state regimes including
fundamental and subharmonic ferroresonance, quasi-periodic
oscillations, and chaos. A detailed analysis of some simulations
demonstrates that the probability of chaos increases as the exponent
of the magnetization curve rises. The effect of varying the
magnitude of the source voltage on the chaotic behaviour of the
circuit is also studied.

This paper numerically investigates the effects of dispersion on
optical fibre chaotic communication, and proposes a dispersion
compensation scheme to improve the performance of optical fibre
chaotic communication system. The obtained results show that the
transmitter--receiver synchronization progressively degrades and the
signal-to-noise ratio of the recovered message deteriorates as the
fibre length increases due to the dispersion accumulation. Two
segments of 2.5-km dispersion-compensating fibres are symmetrically
placed at both ends of a segment of 245-km nonzero
dispersion-shifted fibre with low dispersion in one compensation
period. The numerical results show that the signal-to-noise ratio of
the extracted 1\,GHz sinusoidal message is improved from --2.92\,dB
to 15.38\,dB by this dispersion compensation for the transmission
distance of 500\,km.

We investigate the dynamics of two tunnel-coupled Bose--Einstein
condensates (BECs) in a double-well potential. The effects of the
three-body recombination loss and the feeding of the condensates
from the thermal cloud are studied in the case of attractive
interatomic interaction. An imaginary three-body interaction term is
considered and a two-mode approximation is used to derive three
coupled equations which describe the total atomic numbers of the two
condensates, the relative population and relative phase
respectively. Theoretical analyses and numerical calculations
demonstrate the existence of chaotic and hyperchaotic behaviour by
using a periodically time-varying scattering length.

This paper reports that low-temperature heat capacities of
4-(2-aminoethyl)-phenol (C_{8}H_{11}NO) are measured by a
precision automated adiabatic calorimeter over the temperature range
from 78 to 400\,K. A polynomial equation of heat capacities as a
function of the temperature was fitted by the least square method.
Based on the fitted polynomial, the smoothed heat capacities and
thermodynamic functions of the compound relative to the standard
reference temperature 298.15\,K were calculated and tabulated at the
interval of 5\,K. The energy equivalent, \textit{\varepsilon
}_{\rm calor}, of the oxygen-bomb combustion calorimeter has been
determined from 0.68\,g of NIST 39i benzoic acid to be \textit{
\varepsilon }_{\rm calor}=(14674.69\pm 17.49)J \cdot K^{ -
1}. The constant-volume energy of combustion of the compound at
T=298.15\,K was measured by a precision oxygen-bomb combustion
calorimeter to be \Delta _{\rm c}U=--(32374.25\pm 12.93)J \cdot
g^{ - 1}. The standard molar enthalpy of combustion for the
compound was calculated to be \Delta _{\rm c} H_{\rm m}^\ominus = {
- }(4445.47\pm 1.77)\,{\rm kJ} \cdot \mbox{mol}^{{ - 1}} according
to the definition of enthalpy of combustion and other thermodynamic
principles. Finally, the standard molar enthalpy of formation of the
compound was derived to be \Delta _{\rm f} H_{\rm m}^\ominus (\rm
C_8 H_{11} NO,s){ = - (274.68}\pm 2\mbox{.06)\,kJ} \cdot
\mbox{mol}^{{\rm - 1}}, in accordance with Hess law.

This paper investigates the behaviour of traffic flow in traffic
systems with a new model based on the NaSch model and cluster
approximation of mean-field theory. The proposed model aims at
constructing a mapping relationship between the microcosmic
behaviour and the macroscopic property of traffic flow. Results
demonstrate that scale-free phenomenon of the evolution network
becomes obvious when the density value of traffic flow reaches at
the critical point of phase transition from free flow to traffic
congestion, and jamming is limited in this scale-free structure.

The crystal structure of the minor phase, named superstructure II,
existing in multiferroic compound BiMnO_{3} has been studied by
electron diffraction and high-resolution transmission electron
microscopy. Domains of major and minor phases coexisting in
BiMnO_{3} were observed in high-resolution electron microscope
images. The unit cell of minor phase was determined to be triclinic
with the size 4\times 4\times 4 times as large as the distorted
perovskite subcell. The [111] and [10\bar {1}] projected structure
maps of the minor phase have been derived from the corresponding
images by means of the image processing. A possible rough
three-dimensional (3D) structure model was proposed based on the 3D
structural information extracted from the two projected structure
maps. Since there is no inversion centre in the proposed model, the
minor phase may contribute to the ferroelectric property of
BiMnO_{3}.

We investigate the ^{3}PF_{2} neutron superfluidity in β-stable
neutron star matter and neutron stars by using the BCS theory and
the Brueckner--Hartree--Fock approach. We adopt the Argonne V_{18}
potential supplemented with a microscopic three-body force as the
realistic nucleon--nucleon interaction. We have concentrated on
studying the three-body force effect on the ^{3}PF_{2} neutron pairing
gap. It is found that the three-body force effect is to enhance
remarkably the ^{3}PF_{2} neutron superfluidity in neutron star matter
and neutron stars.

In this paper a new class of finite-dimensional even and odd
nonlinear pair coherent states (EONLPCSs), which can be realized via
operating the superposed evolution operators $D_\pm (\tau )$ on the
state $\left| {q,0} \right\rangle $, is constructed, then their
orthonormalized property, completeness relations and some
nonclassical properties are discussed. It is shown that the
finite-dimensional EONLPCSs possess normalization and completeness
relations. Moreover, the finite-dimensional EONLPCSs exhibit
remarkably different sub-Poissonian distributions and phase
probability distributions for different values of parameters $q$,
$\eta $ and $\xi $.

We have investigated the dispersive properties of excited-doublet
four-level atoms interacting with a weak probe field and an intense
coupling laser field. We have derived an analytical expression of
the dispersion relation for a general excited-doublet four-level
atomic system subject to a one-photon detuning. The numerical
results demonstrate that for a typical rubidium $\rm {D1}$ line
configuration, due to the unequal dipole moments for the transitions
of each ground state to double excited states, generally there
exists no exact dark state in the system. Close to the two-photon
resonance, the probe light can be absorbed or gained and propagate
in the so-called superluminal form. This system may be used as an
optical switch.

Ridge InGaN multi-quantum-well-structure (MQW) edge-emitting laser
diodes (LDs) were grown on (0001) sapphire substrates by
low-pressure metal-organic chemical vapour deposition (MOCVD). The
dielectric TiO$_{2}$/SiO$_{2}$ front and back facet coatings as
cavity mirror facets of the LDs have been deposited with
electron-beam evaporation method. The reflectivity of the designed
front coating is about 50{\%} and that of the back high reflective
coating is as high as 99.9{\%}. Under pulsed current injection at
room temperature, the influences of the dielectric facets were
discussed. The threshold current of the ridge GaN-based LDs was
decreased after the deposition of the back high reflective
dielectric mirrors and decreased again after the front facets were
deposited. Above the threshold, the slope efficiency of the LDs with
both reflective facets was larger than those with only back facets
and without any reflective facets. It is important to design the
reflectivity of the front facets for improving the performance of
GaN-based LDs.

The optical limiting properties of the mixed liquid of carbon black
suspensions (CBS) and green tea solution were studied by using an 8
ns laser pulse at 532\,nm. The optical limiting effects of the CBS
and mixed liquid have been compared between 5 and 10\,Hz repetition
frequencies with nanosecond laser pulse. The experimental results
indicate that the optical limiting threshold of the sample with the
incidence laser at 10\,Hz repetition frequency is lower than at
5\,Hz repetition frequency. The possible reasons for the influence
of the repetition frequency on the samples are discussed. And by
observing the optical radiant distributions when the laser pulse
passing through different samples, a possible mechanism for the
observed effects is suggested. At the same time, the result shows
that the optical limiting of CBS is the dominant factor to optical
limiting of the mixed liquid.

This paper describes the evolution of vapour bubbles and its effect
on nonlinear ultrasound propagation and temperature rise through
tissues for therapeutic ultrasound. An acoustic-thermo coupling
algorithm incorporating nonlinearity, diffraction, and
temperature-dependent tissue properties, is employed to describe
nonlinear ultrasound propagation and thermal effect. Results
demonstrate that an obvious migration of peak pressure toward
transducer surface is observed while the position of peak
temperature changes little in liver tissue before the generation of
vapour bubbles, and that the boiling region enlarges towards the
surface of transducer in axial direction but increases slowly in
radial direction after the generation of vapour bubbles.

A one-dimensional (1D) Frenkel--Kontorova (FK) model is studied
numerically in this paper, and two new analytical solutions (a
supersonic kink and a nonlinear periodic wave) of the Sine--Gordon
(SG) equation (continuum limit approximation of the FK model) are
obtained by using the Jacobi elliptic function expansion method.
Taking these new solutions as initial conditions for the FK model,
we numerically find there exist the supersonic kink and the
nonlinear periodic wave in these systems and obtain a lot of
interesting and significant results. Moreover, we also investigate
the subsonic kink and the breather in these systems and obtain some
new feature.

In the present paper, the random interfacial waves in $N$-layer
density-stratified fluids moving at different steady uniform speeds
are researched by using an expansion technique, and the second-order
asymptotic solutions of the random displacements of the density
interfaces and the associated velocity potentials in $N$-layer fluid
are presented based on the small amplitude wave theory. The obtained
results indicate that the wave--wave second-order nonlinear
interactions of the wave components and the second-order nonlinear
interactions between the waves and currents are described. As
expected, the solutions include those derived by Chen (2006) as a
special case where the steady uniform currents of the $N$-layer
fluids are taken as zero, and the solutions also reduce to those
obtained by Song (2005) for second-order solutions for random
interfacial waves with steady uniform currents if $N = 2$.

This paper calculates the transition wavelengths and probabilities
of the two-electron and one-photon (TEOP) transition from the
$(3{\rm s}^{-1}_{1/2}4{\rm d}_{j})_{J=1,2}$ to $(3{\rm
p}^{-1}_{3/2}4{\rm s}_{1/2})_{J=1}$ and the $(3{\rm
p}^{-1}_{1/2}4{\rm s}_{1/2})_{J=1}$ to $(3{\rm d}^{-1}_{j}4{\rm
d}_{j'})_{J=1,2}$ for highly charged Ni-like ions with atomic number
$Z$ in the range $47\leq Z\leq92$. In the calculations, the
multi-configuration Dirac--Fock method and corresponding program
packages GRASP92 and REOS99 were used, and the relativistic effects,
correlation effects and relaxation effects were considered
systematically. It is found that the TEOP transitions are very
sensitive to the correlation of electrons, and the probabilities
will be enhanced sharply in some special $Z$ regions along the
isoelectronic sequence. The present TEOP transition wavelengths are
compared with the available data from some previous publications,
good agreement is obtained.

This paper reports that hexagonal-phase LaF$_{3}$:Yb$^{3 +
}_{0.20}$, Er$^{3 + }_{0.02}$ and LaF$_{3}$:Yb$^{3 + }_{0.20}$,
Tm$^{3 + }_{0.02}$ nanocrystals (NCs) were synthesized via a
hydrothermal method. The transmission electron microscopy, selected
area electron diffraction, powder x-ray diffraction, and
thermogravimetric analysis are used to characterize the NCs. Under
980 nm excitation, the Yb$^{3 + }$/Er$^{3 + }$ and Yb$^{3 +
}$/Tm$^{3 + }$ codoped NCs colloidal solutions present bright green
and blue upconversion fluorescence, respectively. These NCs show
efficient infrared-to-violet and infrared-to-visible upconversion.
The upconversion fluorescence mechanisms of LaF$_{3}$:Yb$^{3 +
}_{0.20}$, Er$^{3 + }_{0.02}$ and LaF$_{3}$:Yb$^{3 + }_{0.20}$,
Tm$^{3 + }_{0.02}$ NCs are investigated with a 980-nm diode laser as
excitation source.

This paper reports the experimental results on electromagnetically
induced absorption (EIA) spectra observed in the system which does
not satisfy completely the conditions given by Lezama {\it et al}
[1999 \wx{Phys. Rev. {\rm A}}{59} 4732]. EIA signals on the
transitions in the Cs $D_{2}$ line are able to be observed, where
$F_{\rm g} \leftrightarrow F_{\rm e}=F_{\rm g}-1$ as open systems.
Theoretical model of Lezama {\it et al} is good for the case $F_{\rm
g} \leftrightarrow F_{\rm e}=F_{\rm g}+1$, considering spontaneous
transfer of atomic coherences or populations this model is not able
to explain our experimental results obtained in the case $F_{\rm g}
\leftrightarrow F_{\rm e}=F_{\rm g}-1$. This paper offers a
theoretical model which is able to well explain the case $F_{\rm g}
\leftrightarrow F_{\rm e}=F_{\rm g}-1$. It also uses this
theoretical model to explain the split and shift of EIA peaks, which
have been obtained in experiments.

This paper reports that polarized far-infrared reflectivity
measurements have been done on LiGaO_{2} single crystal along two
crystalline axes at different temperatures. The temperature
dependent frequencies of the longitudinal and transverse optical
phonon have been obtained from the real part of optical conductivity
and the loss function respectively. A small Drude component is
observed at frequency below 300\,cm$^{ - 1}$ which could arise from
Li ions or oxygen deficiencies. The ionicity of LiGaO_{2} has been
studied from the analysis of the Born effective charge of different
ions.

This paper carries out {\it ab initio} calculations to study the
^{80}Se_{2}(X^{3}\Sigma_{g}^{-}) state and
^{80}Se_{2}^{+}(X^{2}\Pi_{g},
^{80}Se_{2}^{+}(a^{4}\Pi_{g}) states by using completed active
space self-consistent field and multi-reference second order
perturbation theory. The electronic curves of these states including
spin--orbit coupling are calculated, and then the spectroscopic
parameters are obtained. The photoelectron spectra of
^{80}Se_{2} molecule in gas phase are assigned according to
Franck--Condon analysis based on calculated potential energy curves.
The ionization energies of ^{80}Se_{2} molecule are determined
by the present calculation.

The anisotropic potential developed in our previous research and the
close-coupling method are applied to the HBr--$^{3}$He ($^{4}$He,
$^{5}$He, $^{6}$He, $^{7}$He) system, and the partial cross sections
(PCSs) at the incident energy of 60\,meV are calculated. Based on
the calculations, the influences of the isotope helium atom on PCSs
are discussed in detail. The results show that the excitation PCSs
converge faster than the elastic PCSs for the collision energy and
the systems considered here. Also the excitation PCSs converge more
rapidly for the high-excited states. The tail effect is present only
in elastic scattering and low-excited states but not in high-excited
states. With the increase of reduced mass of the collision system,
the converging speed of the elastic and excitation PCSs slows down,
and the tail effect goes up.

The structure and binding energy of copper clusters of the size
range 70 to 150 were studied by using the embedded-atom method. The
stability of the structure of the clusters was studied by
calculating the average binding energy per atom, first difference
energy and second difference energy of copper cluster. Most of the
copper clusters of the size $n$=70--150 adopt an icosahedral
structure. The results show that the trends are in agreement with
theoretic prediction for copper clusters. The most stable structures
for copper clusters are found at $n$=77, 90, 95, 131, 139.

Based on the density-functional theory, this paper studies the
geometric and magnetic properties of Ti$_{n}$O ($n$=1--9) clusters.
The resulting geometries show that the oxygen atom remains on the
surface of clusters and does not change the geometry of Ti$_{n}$
significantly. The binding energy, second-order energy differences
with the size of clusters show that Ti$_{7}$O cluster is endowed
with special stability. The stability of Ti$_{n}$O clusters is
validated by the recent time-of-flight mass spectra. The total
magnetic moments for Ti$_{n}$O clusters with $n$=1--4, 8--9 are
constant with 2 and drop to zero at $n$=5--7. The local magnetic
moment and charge partition of each atom, and the density of states
are discussed. The magnetic moment of the Ti$_{n}$O is clearly
dominated by the localized 3d electrons of Ti atoms while the oxygen
atom contributes a very small amount of spin in Ti$_{n}$O clusters.

This paper studies the coalescence of heteroclusters Au$_{767}$ and
Ag$_{767}$ by using molecular dynamics with the embedded atom
method, where layer atomic energy is employed to describe the
potential energy variation of per atom in different layers along
radial direction. The results show that the coalescence is driven by
releasing the atomic energy of the coalesced zone. The deformation,
which is induced by substitutional and vacancy diffusion during the
coalescence, makes the coalesced cluster disorder. If the summation
of the thermal energy and the released atomic energy is large enough
to keep the disorder state, the clusters form a metastable liquid
droplet; otherwise, the clusters coalesce into a solid cluster when
the coalesced cluster reaches the equilibrium state, and the
coalesced cluster experiences liquid to solid ordering changes
during the coalescence of a solid Au$_{767}$ with a liquid
Ag$_{767}$ and a liquid Au$_{767}$ with a liquid Ag$_{767}$. The
centre of figure of the cluster system is shifted during the
coalescence process, and higher coalescence temperature causes
larger shift degree.

PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES

It is of great importance for engineering applications to obtain the
expression of scattering field for an ellipsoidal target irradiated
by an electromagnetic wave from an arbitrary direction.
Literature relevant to this problem is seldom found. In this paper,
the scattering field for an ellipsoidal target is presented by
utilizing the scale transformation of electromagnetic field and the
rotation of coordinate system, with an electromagnetic wave
projecting on the target from an arbitrary direction. The obtained
result is in good agreement with the solution available from the
literature if we consider the scale factors to be unity. Taking a
conducting ellipsoidal target for sample, we perform the partial
simulations of the ellipsoidal model and a plant leaf model by
choosing different scale factors. The obtained results show that the
distribution characteristic of scattering field is sensitively
affected by the polarization of the incident wave and varies not
much with the incident wave angle but changes with the observation
point. At some points the scattering energy arrives at its maximum.

An extended interaction oscillator (EIO) generating 120\,GHz wave in
sub-terahertz waves is studied by using the three-dimensional
electromagnetic simulation software CST and PIC codes. A rectangular
reentrant coupled-cavity is proposed as the slow-wave structure of
EIO. By CST, the circuit parameters including frequency-phase
dispersion, interaction impedance and characteristic impedance are
simulated and calculated. The operation mode of EIO is chosen very
close to the point where $\beta L=2\pi$ with corresponding frequency
120\,GHz, the beam voltage 12\,kV and the dimensions of the cavity
with the period 0.5\,mm, the height 3\,mm and the width 1.4\,mm.
Simulation results of beam--wave interaction by PIC show that the
exciting frequency is 120.85\,GHz and output peak power 465\,W with
12-period coupled-cavity with the perveance 0.17\,$\mu$P. Simulation
results indicate that the EIO has very wide range of the operation
voltage.

CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES

Transparent Yb doped YAG, YSAG and YaLaO_{3} ceramics are
fabricated by using the co-precipitation method. The spectral
properties and thermal parameters of these Yb doped cubic phase
transparent ceramics are compared, and their different and potential
applications are also analysed. The absorption cross-section and the
emission cross-section of these ceramics are measured and
calculated. The essential properties of these materials especially
for the rep-rated pulsed high-energy diode-pumped solid-state lasers
are investigated. The results show that Yb doped YAG, YSAG and
YaLaO$_3$ are all suitable materials used for diode-pumped
solid-state lasers.

This paper applies techniques of containerless processing, drop tube
and glass fluxing, to undercool and solidify Ni_{77}P_{23}
alloys. Different diameter spheres were collected at the bottom of a
52-m long drop tube. Both crystalline and amorphous phase were
formed in various size specimens due to the different cooling rate.
The variation of partial undercooling with bulk undercooling is
calculated for the Ni_{77}P_{23} alloys. The deep undercooling
and rapid solidification behaviour of Ni_{77}P_{23} melts has
been analysed with respect to microstructure formation and
transition during fluxing and 52-m drop process of undercooled
melts.

In order to search for promising candidates for spintronic
applications, this paper systematically studies three ternary
compounds based on Mn_{5}Ge_{3} by using a full-potential
linearized augmented plane wave method within the density functional
theory. Through structure optimization and electronic structure
calculations, it finds that Mn_{4}FeGe_{3} and
Mn_{4}CoGe_{3} have much higher spin-polarization than original
intermetallic compound Mn_{5}Ge_{3}, although the spin
polarization of Mn_{4}NiGe_{3} is lower than that of
Mn$_{5}$Ge_{3}. The calculated result is in agreement with
experiment in the case of Mn_{4}FeGe_{3}. Both of them can be
taken as promising candidates for spintronics applications because
of their high spin-polarization and compatibility with
semiconductors.

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

This paper investigates the mechanism of Li insertion into
interphase Ni$_{3}$Sn in Ni--Sn alloy for the anode of lithium ion
battery by means of the first-principles plane-wave pseudopotential.
Compared with other phases, it is found that the Ni$_{3}$Sn has
larger relative expansion ratio and lower electrochemical potential,
with its specific plateaus voltage around 0.3eV when lithium atoms
are filled in all octahedral interstitial sites, and the relative
expansion ratio increasing dramatically when the lithiated phase
transits from octahedral interstitial sites to tetrahedral
interstitial sites. So this phase is a devastating phase for whole
alloy electrode materials.

Plasma doping is the candidate for semiconductor doping. Accurate
simulation of the doping technology is needed for the advanced
integrated circuit manufacturing. In this paper, the plasma
doping process simulation is performed by using the localized
molecular dynamics method. Models that involve the statistics of the
implanted compositions, angles and energies are developed. The
effect of the model on simulation results is studied. The simulation
results about the doping concentration profile are supported by
experimental data.

Electronic and optical properties of single-walled zinc oxide (ZnO)
nanotubes are investigated from the first-principles calculations.
Electronic structure calculations show that ZnO nanotubes are all
direct band gap semiconducting nanotubes and the band gaps are
relatively insensitive to the diameter and chirality of tubes. The
origin of the common electronic band gaps of ZnO nanotubes is
explained in terms of band-folding from the two-dimensional band
structure of graphite-like sheet. Moreover, the optical properties
such as dielectric function and energy loss function spectra of
different ZnO nanotubes are very similar, relatively independent of
diameter and chirality of tubes. The calculated dielectric function
and loss function spectra show a moderate optical anisotropy with
respect to light polarization.

We use the transfer matrix method to study the quantum tunnelling
through an indirect-band-gap double-barrier like the
GaAs/AlAs/GaAs/AlAs/GaAs heterostructures along the [001] axis,
which is described by the tight-binding model. The $X$-valley
quasi-bound state gives rise to the Fano resonance different from
the direct double-barrier transition in a resonance-tunnelling diode.
The quantitative calculations demonstrate that a relatively high
spin-polarization of the transmission probability can be achieved as
compared with the single-barrier tunnelling case. Moreover the
extension to the multi-barrier device is provided and leads to an
important observation that the spin polarization increases with the
number of barriers.

A single ZnO nanowire with intrinsic oxygen vacancies is utilized to
fabricate four-contact device with focus ion beam lithography
technique. Cathodoluminescent spectra indicate strong near-UV and
green emission at both room temperature and low temperatures.
Experimental measurement shows the temperature-dependent
conductivity of the ZnO nanowire at low temperatures (below 100\,K).
The further theoretical analysis confirms that weak localization
plays an important role in the electrical transport, which is
attributed to the surface states induced by plenty of oxygen
vacancies in ZnO nanowire.

A new preparing technology, very high frequency plasma assisted
reactive thermal chemical vapour deposition (VHFPA-RTCVD), is
introduced to prepare SiGe:H thin films on substrate kept at a lower
temperature. In the previous work, reactive thermal chemical vapour
deposition (RTCVD) technology was successfully used to prepare
SiGe:H thin films, but the temperature of the substrate needed to
exceed 400\du. In this work, very high frequency plasma method is
used to assist RTCVD technology in reducing the temperature of
substrate by largely enhancing the temperature of reacting gases on
the surface of the substrate. The growth rate, structural
properties, surface morphology, photo-conductivity and
dark-conductivity of SiGe:H thin films prepared by this new
technology are investigated for films with different germanium
concentrations, and the experimental results are discussed.

This paper investigates the procedure of cubic boron nitride (cBN)
thin film delamination by Fourier-transform infrared (IR)
spectroscopy. It finds that the apparent IR absorption peak area
near 1380\,cm$^{-1}$ and 1073\,cm$^{-1}$ attributed to the B--N
stretching vibration of sp$^{2}$-bonded BN and the transverse
optical phonon of cBN, respectively, increased up to 195{\%} and
175{\%} of the original peak area after film delamination induced
compressive stress relaxation. The increase of IR absorption of
sp$^{2}$-bonded BN is found to be non-linear and hysteretic to film
delamination, which suggests that the relaxation of the turbostratic
BN (tBN) layer from the compressed condition is also hysteretic to
film delamination. Moreover, cross-sectional transmission electron
microscopic observations revealed that cBN film delamination
is possible
from near the aBN(amorphous BN)/tBN interface at least
for films prepared by plasma-enhanced chemical vapour deposition.

This paper employs micro-Raman technique for detailed analysis of
the defects (both inside and outside) in bulk 4H-SiC. The main peaks
of the first-order Raman spectrum obtained in the centre of defect
agree well with those of perfect bulk 4H-SiC, which indicate that
there is no parasitic polytype in the round pit and the hexagonal
defect. Four electronic Raman scattering peaks from nitrogen defect
levels are observed in the round pit (395\,cm$^{-1}$,
526\,cm$^{-1}$, 572\,cm$^{-1}$, and 635\,cm$^{-1})$, but cannot be
found in the spectra of hexagonal defect. The theoretical analysis
of the longitudinal optical plasmon--phonon coupled mode line shape
indicates the nonuniformity of nitrogen distribution between the
hexagonal defect and the outer area in 4H-SiC. The second-order
Raman features of the defects in bulk 4H-SiC are well-defined using
the selection rules for second-order scattering in wurtzite
structure and compared with that in the free defect zone.

This paper reports that the intrinsic microcrystalline silicon ($\mu
$c-Si:H) films are prepared with plasma enhanced chemical vapour
deposition from silane/hydrogen mixtures at 200\du\ with the aim to
increase the deposition rate. An increase of the deposition rate to
0.88\,nm/s is obtained by using a plasma excitation frequency of
75\,MHz. This increase is obtained by the combination of a higher
deposition pressure, an increased silane concentration, and higher
discharge powers. In addition, the transient behaviour, which can
decrease the film crystallinity, could be prevented by filling the
background gas with H$_{2}$ prior to plasma ignition, and selecting
proper discharging time after silane flow injection. Material
prepared under these conditions at a deposition rate of 0.78\,nm/s
maintains higher crystallinity and fine electronic properties. By
H-plasma treatment before i-layer deposition, single junction $\mu
$c-Si:H solar cells with 5.5{\%} efficiency are fabricated.

This paper presents a finite element method of calculating strain
distributions in and around the self-organized GaN/AlN hexagonal
quantum dots. The model is based on the continuum elastic theory,
which is capable of treating a quantum dot with an arbitrary shape.
A truncated hexagonal pyramid shaped quantum dot is adopted in this
paper. The electronic energy levels of the GaN/AlN system are
calculated by solving a three-dimension effective mass
Shr\"{o}dinger equation including a strain modified confinement
potential and polarization effects. The calculations support the
previous results published in the literature.

The hole subband structures and effective masses of tensile strained
Si/Si$_{1 - y }$Ge$_{y}$ quantum wells are calculated by using the
6$\times $6 $\bm k\cdot\bm p$ method. The results show that when the
tensile strain is induced in the quantum well, the light-hole state
becomes the ground state, and the light hole effective masses in the
growth direction are strongly reduced while the in-plane effective
masses are considerable. Quantitative calculation of the valence
intersubband transition between two light hole states in a 7nm
tensile strained Si/Si$_{0.55}$Ge$_{0.45}$ quantum well grown on a
relaxed Si$_{0.5}$Ge$_{0.5}$ (100) substrates shows a large
absorption coefficient of 8400\,cm$^{ - 1}$.

This paper reports that the YBa$_{2}$Cu$_{3 - x}$Zn$_{x}$O$_{7 -
\delta }\ (x=0-0.4$) samples are researched by means of x-ray
diffraction, calculations of binding energy, the positron
experiments and variations of oxygen content. The results of
simulated calculations, positron experiments and variations of
oxygen content support the existence of cluster effect. Moreover, it
is concluded that the cluster effect is an important factor on
suppression of high-$T_{\rm c}$ cuprate superconductivity and the
$T_{\rm c}$ does not depend on the density of valence electron
directly.

This paper reports that high quality CuGeO$_{3}$ single crystals
were successfully grown by floating-zone technique and the magnetic
property was studied. The temperature dependence of magnetic
susceptibility below the spin-Peierls (SP) transition temperature
($T_{\rm sp})$ under magnetic fields applying along both the $a$-
and $c$-axis direction can be fitted well by a model of
noninteracting dimmers. The spin gap derived from the fitting is
consistent with other reports. There is a very weak anisotropy in
the fitting parameters for different directions, which should be
expected from a SP system. A small upturn in susceptibility at low
temperature due to paramagnetic impurities and/or defects can be
observed. A suppression of the upturn by magnetic field is first
discovered in this system and the possible origins for this
suppression are discussed.

The temperature-driven spin reorientation transition of magnetron
sputtered Ni/Si (111) systems has been studied. The relationship
between ac initial susceptibility and temperature of nickel films
with different thicknesses shows that the magnetization orientation
changes from in-plane to out-of-plane with the increase of
temperature. The temperature dependence of magnetoelastic,
magneto-crystalline, and magnetostatic anisotropies determines the
direction of the reorientation transition. The temperature-driven
spin reorientation transition is supported by Hall coefficient
measurements which show that its temperature dependence is similar
to that of susceptibility.

An iron film percolation system is fabricated by vapour-phase
deposition on fracture surfaces of α-Al_{2}O_{3} ceramics.
The zero-field-cooled (ZFC) and field-cooled (FC) magnetization
measurement reveals that the magnetic phase of the film samples
evolve from a high-temperature ferromagnetic state to a
low-temperature spin-glass-like state, which is also demonstrated by
the temperature-dependent ac susceptibility of the iron films. The
temperature dependence of the exchange bias field $H_{\rm e}$ of the
iron film exhibits a minimum peak around the temperature $T$=5\,K,
which is independent of the magnitude of the cooling field $H_{\rm
cf}$. However, for $T > 10$\,K, (1) $H_{\rm e}$ is always negative
when $H_{\rm cf}$=2\,kOe and (2) for $H_{\rm cf }$= 20\,kOe
(1Oe$\approx$80\,A/m), $H_{\rm e}$ changes from negative to positive
values as T increases. Our experimental results show that the
anomalous hysteresis properties mainly result from the oxide
surfaces of the films with spin-glass-like phase.

The effects of metal core dimension, oxide shell thickness and
ellipsoid aspect ratio of Al--Al$_{2}$O$_{3}$ core-shell
nanoparticles on the near-infrared and visible absorption spectra of
nanocomposite Al--Al$_{2}$O$_{3}$/nitrocellulose(NC) film are
investigated by numerical calculations. Both the size-dependent
interband transitions and frequency-dependent free electron damping
of the nanometallic aluminium are taken into account in the
calculations. Oxidation effect of nanoaluminium is also analysed. It
is shown that oxidation may enhance but may also reduce the optical
absorption, depending on the excited light energy and initial
dimension of nanoparticle. Metal core size and excited light energy
dominate the absorption characteristic. The absorption ability of
ellipsoidal nanoparticles is larger than that of spheroidal
nanoparticles and increases by the square index as the aspect ratio
increases. These calculations will provide some significant
theoretical guidance for the preparation and laser ignition of
nanoenergetic materials.