In this paper a scheme for quantum secure direct communication
(QSDC) network is proposed with a sequence of polarized single
photons. The single photons are prepared originally in the same
state $\vert 0\rangle$ by the servers on the network, which will
reduce the difficulty for the legitimate users to check
eavesdropping largely. The users code the information on the single
photons with two unitary operations which do not change their
measuring bases. Some decoy photons, which are produced by operating
the sample photons with a Hadamard, are used for preventing a
potentially dishonest server from eavesdropping the quantum lines
freely. This scheme is an economical one as it is the easiest way
for QSDC network communication securely.

By introducing the double complex scalar field, this paper constructs
the double Lagrangian with the potential $V({\it\Phi}(J),
{\it\Phi}^{*}(J))=V(|{\it\Phi}(J)|)$, which not only can describe the
evolution of quintom Universe, but also can naturally give the
spintessence and hessence Universe. Furthermore, the $U(1,J)$
symmetry of the double complex Lagrangian is verified, and the total
conserved charge within the physical volume is derived by means of
the No\"{e}ther theorem. Moreover, it can point out that the
`imaginary motion' of the angular
parameter in Ref.[14], in fact, is only a real phase displacement in
our model.

We investigate an evolutionary snowdrift game on a square $N=L\times
L$ lattice with periodic boundary conditions, where a population of
$n_{0}$ ($n_{0}\leq N$) players located on the sites of this lattice
can either cooperate with or defect from their nearest neighbours.
After each generation, every player moves with a certain probability
$p$ to one of the player's nearest empty sites. It is shown that,
when $p=0$, the cooperative behaviour can be enhanced in disordered
structures. When $p>0$, the effect of mobility on cooperation
remarkably depends on the payoff parameter $r$ and the density of
individuals $\rho$ ($\rho=n_{0}/N$). Compared with the results of
$p=0$, for small $r$, the persistence of cooperation is enhanced at
not too small values of $\rho$; whereas for large $r$, the
introduction of mobility inhibits the emergence of cooperation at any
$\rho<1$; for the intermediate value of $r$, the cooperative
behaviour is sometimes enhanced and sometimes inhibited, depending on
the values of $p$ and $\rho$. In particular, the cooperator density
can reach its maximum when the values of $p$ and $\rho$ reach their
respective optimal values. In addition, two absorbing states of all
cooperators and all defectors can emerge respectively for small and
large $r$ in the case of $p>0$.

Complex networks have been applied to model numerous interactive
nonlinear systems in the real world. Knowledge about network topology
is crucial to an understanding of the function, performance and
evolution of complex systems. In the last few years, many network
metrics and models have been proposed to investigate the network
topology, dynamics and evolution. Since these network metrics and
models are derived from a wide range of studies, a systematic study
is required to investigate the correlations among them. The present
paper explores the effect of degree correlation on the other network
metrics through studying an ensemble of graphs where the degree
sequence (set of degrees) is fixed. We show that to some extent, the
characteristic path length, clustering coefficient, modular extent
and robustness of networks are directly influenced by the degree
correlation.

In this paper, the Faddeev--Jackiw approach is improved by the Wu
elimination method, so a great many complicated computations in
solving constraints for the finite-dimensional polynomial-type
constrained dynamics can be executed easily by using computers.
Moreover, based on the Faddeev--Jackiw approach, a new algorithm of
solving the constrained dynamics is presented. The new algorithm is
simpler and stricter than the Faddeev--Jackiw approach. Using the new
algorithm, the second Cawley counterexample is solved.

This paper considers interfacial waves propagating along the
interface between a two-dimensional two-fluid with a flat bottom and
a rigid upper boundary. There is a light fluid layer overlying a
heavier one in the system, and a small density difference exists
between the two layers. It just focuses on the weakly non-linear
small amplitude waves by introducing two small independent
parameters: the nonlinearity ratio $\varepsilon $, represented by
the ratio of amplitude to depth, and the dispersion ratio $\mu $,
represented by the square of the ratio of depth to wave length,
which quantify the relative importance of nonlinearity and
dispersion. It derives an extended KdV equation of the interfacial
waves using the method adopted by Dullin {\it et al} in the study of
the surface waves when considering the order up to $O(\mu ^2)$. As
expected, the equation derived from the present work includes, as
special cases, those obtained by Dullin {\it et al} for surface
waves when the surface tension is neglected. The equation derived
using an alternative method here is the same as the equation
presented by Choi and Camassa. Also it solves the equation by
borrowing the method presented by Marchant used for surface waves,
and obtains its asymptotic solitary wave solutions when the weakly
nonlinear and weakly dispersive terms are balanced in the extended
KdV equation.

We investigate the pairwise entanglement and global entanglement in a
generalized Jaynes--Cummings model, which can be used to realize
Greenberger--Horne--Zeilinger (GHZ) entangled state (Zheng S B 2001
{\it Phys. Rev. Lett.} {\bf 87} 230404). Our results show that the
W-type entangled states cannot be generated based on the model. The
dependences of entanglement on Rabi frequency $\lambda$ and
dipole--dipole coupling strength ${\it \Omega}$ are given. It is
found that there exists the quantum phase transition when
$\lambda={\it \Omega}$. For typical experimental data, the critical
temperature for pairwise entanglement is on the order of
$10^{-6}$\,K. Based on these results, two strategies that overcome
decoherence are proposed.

We propose a scheme for implementing the Grover search algorithm
with two superconducting quantum interference devices (SQUIDs) in a
cavity. Our scheme only requires single resonant interaction of the
SQUID-cavity system and the required interaction time is very short.
The simplicity of the process and the reduction of the interaction
time are important for restraining decoherence.

Application of the first junction condition to a highly symmetric
spacetime was investigated recently in {\it Chin. Phys. Lett.} B {\bf
546} 189 2006, where a partial differential equation arising from the
connection of the Robertson--Walker and the Schwarzschild--de Sitter
metrics was presented, but no solutions of the equation were
provided. Here we provide a proof to the statement that there exist
solutions of the equation. In addition, an example of the solution
and some analyses associated with this issue are presented. We find
that in connecting the two metrics, there are three conditions which
should be satisfied. Of these conditions, one condition constrains
the place where the two metrics can take the same value for a local
system whose mass is provided which marks the boundary of the system,
and the other two constrain the transformation form. In realizing the
connection of the two metrics, the latter two conditions are required
to be satisfied only at the boundary defined by the former condition.

This paper studies the finite statistical-mechanical entropy of the
Schwarzschild anti-de Sitter (AdS) spacetime arising from quantum
massless scalar field by using the `brick wall' approach in the
Painlev\'e and Lemaitre coordinates. At first glance, it seems that
the results would be different from that in the Schwarzschild-like
coordinate since both the Painlev\'e and the Lemaitre spacetimes do
not possess the event horizon obviously. However, this paper proves
that the entropies in these coordinates are exactly equivalent to
that in the Schwarzschild-like coordinate.

In recent years, the chaos based cryptographic algorithms have
suggested some new and efficient ways to develop secure image
encryption techniques. This paper proposes a new approach for image
encryption based on a high-dimensional chaotic map. The new scheme
employs the Cat map to shuffle the positions, then to confuse the
relationship between the cipher-image and the plain-image using the
high-dimensional Lorenz chaotic map preprocessed. The results of
experimental, statistical analysis and key space analysis show that
the proposed image encryption scheme provides an efficient and secure
way for real-time image encryption and transmission.

The influences on the neutrino energy loss rates in iron group nuclei
at the same density are investigated in the presence of strong
electron screening and in the absence of electron screening. The
results show that at a temperature of $15\ti10^9$\,K, the neutrino
energy loss rates which come from the electron capture process for
most iron group nuclei decrease no more than 2 orders of magnitude
but for the others (such as $^{53,55,56,57,58,59,60}$Co,
$^{56,59}$Ni) they can decrease about 3 orders of magnitude due to
strong electron screening (SES), whereas, at a temperature of $10^9K$
the neutrino energy loss rates of the most iron group nuclei can be
diminished greatly due to the SES. For example, $^{61}$Fe, $^{60}$Fe,
and $^{62}$Ni the neutrino energy loss rates decrease about 4, 15 and
16 orders of magnitude and for $^{57}$Cr, $^{58}$Cr, and $^{60}$Cr
decrease about 18, 12, and 10 orders of magnitude respectively.
According to our calculations the neutrino energy loss rates of
nuclei $^{58}$Mn, $^{59}$Mn, $^{60}$Mn, and $^{62}$Mn may decrease
about 13 orders of magnitude at a temperature of $10^9$\,K due to the
SES.

The model of the Coulomb dressed potential is applied to solving the
problem of electron scattering for simplifying the calculation in the
electrostatic field and the excimer laser field. The introduction and
the application of the model are based on the electric dipole
approximation, so the contribution of the electric multipole is
neglected. In this paper, rigorous analysis and deduction are
carried out for the introduction of the dressed Coulomb potential
into the laser field. It is found that the introduction of the
dressed potential in the fractional form is feasible only when the
laser field (not including far ultraviolet field and x-ray) is a weak
field, i.e. the quiver radius of the free electron is smaller than
the atomic scale. In addition, the necessary analysis is also
conducted of the limitation of the application of the Coulomb dressed
potential.

The structural stability and magnetic properties of the icosahedral
Ni$_{13}$, Ni$_{13}^{ + 1}$ and Ni$_{13}^{ - 1}$ clusters have been
obtained by utilizing all-electron density functional theory with the
generalized gradient approximations for the exchange-correlation
energy. The calculated results show that the ground states of neutral
and charged clusters all favour a $D_{3d}$ structure, a distorted
icosahedron, due to the Jahn--Teller effect. The radial distortions
caused by doping one electron and by doping one hole are opposite to
each other. Doping one electron will result in a 1/2 decrease and
doping one hole will result in a 1/2 increase of the total spin. Both
increasing interatomic spacing and decreasing coordination will lead
to an enhancement of the spin magnetic moments for Ni$_{13}$
clusters.

This paper has studied the barium spectra in external magnetic and
electric fields on the recently-built system based on a
super-conducting solenoid with high stability of better than 1 Gauss.
Firstly, we compared the spectra in a high pure magnetic field of
$B=4.00000$\,T for different polarized laser, $\sigma^{+}$ and
$\sigma^-$. We prove that after a proper shift, the $\sigma^+$ and
$\sigma^-$ spectra are completely identical. We also investigated the
dependence of the spectral feature in the high magnetic field on an
additionally applied crossing electric field. Along with the increase
of the electric field, there is an energy shift for every spectral
line. Based on a transformative Hamiltonian, we explained this energy
shift well.

We propose a novel scheme in which cold polar molecules are trapped
by an electrostatic field generated by the combination of a pair of
parallel transparent electrodes (i.e., two infinite transparent
plates) and a ring electrode (i.e., a ring wire). The spatial
distributions of the electrostatic fields from the above charged wire
and the charged plates and the corresponding Stark potentials for
cold CO molecules are calculated; the dependences of the trap centre
position on the geometric parameters of the electrode are analysed.
We also discuss the loading process of cold molecules from a cold
molecular beam into our trap. This study shows that the proposed
scheme is not only simple and convenient to trap, manipulate and
control cold polar molecules in weak-field-seeking states, but also
provides an opportunity to study cold collisions and collective
quantum effects in a variety of cold molecular systems, etc.

The photoionization of seeded carbon bisulfide molecular beam by a
1064\,nm nanosecond Nd-YAG laser with intensities varying from
$0.8\times10^{11}$ to $5.6\times10^{11}$\,W/cm$^{2}$ have been
studied by time-of-flight mass spectrometry. Multiply charged ions
of S$^{q + }$ ($q$ = 2--6) and C$^{q +}$ ($q$ = 2--4) with kinetic
energy of hundreds of electron volts have been observed, and there
are strong experimental evidences indicating that those multicharged
ions originate from the ionization of CS$_{2}$ neat clusters in the
beam. An electron recolliding ionization model is proposed to
explain the appearance of those multiply charged atomic ions under
such low laser intensities.

A single particle magneto-confined in a one-dimensional (1D) quantum
wire experiences a harmonic potential, and imposing a sharply
focused laser beam on an appropriate site shapes a $\delta$
potential. The theoretical investigation has demonstrated that for a
sufficiently strong $\delta$ pulse the quantum motional stationary
state of the particle is one of the eigenstates of the free harmonic
oscillator, and it is determined by the site of the laser beam
uniquely, namely a quantum state is admissible if and only if the
laser site is one of its nodes. The numerical computation shows that
all the nodes of the lower energy states with quantum numbers $n \le
20$, except the coordinate origin, are mutually different. So we can
manipulate the multiphoton transitions between the quantum states by
adjusting the position of the laser $\delta$ pulse and realize the
transition from an unknown higher excitation state to a required
lower energy state.

The potential energy curves (PECs) of the ground state ($^{3}\Pi )$
and three low-lying excited states ($^{1}\Sigma $, $^{3}\Sigma $,$^{
1}\Pi )$ of CdSe dimer have been studied by employing
quasirelativistic effective core potentials on the basis of the
complete active space self-consistent field method followed by
multireference configuration interaction calculation. The four PECs
are fitted to analytical potential energy functions using the
Murrel--Sorbie potential function. Based on the PECs, the vibrational
levels of the four states are determined by solving the
Schr\"{o}dinger equation of nuclear motion, and corresponding
spectroscopic constants are accurately calculated. The equilibrium
positions as well as the spectroscopic constants and the vibrational
levels are reported. By our analysis, the $^{3}\Pi $ state, of which
the dissociation asymptote is Cd($^{1}$S) + Se($^{3}$P), is
identified as a ground state of CdSe dimer, and the corresponding
dissociation energy is estimated to be 0.39\,eV. However, the first
excited state is only 1132.49\,cm$^{ - 1}$ above the ground state and
the $^{3}\Sigma $ state is the highest in the four calculated states.

The density functional theory (DFT)(b3p86) of Gaussian 03 has been
used to optimize the structure of the Co$_{2}$ molecule, a transition
metal element molecule. The result shows that the ground state for
the Co$_{2}$ molecule is a 7-multiple state, indicating a spin
polarization effect in the Co$_{2}$ molecule. Meanwhile, we have not
found any spin pollution because the wavefunction of the ground state
is not mingled with wavefunctions of higher-energy states. So for the
ground state of Co$_{2}$ molecule to be a 7-multiple state is the
indicative of spin polarization effect of the Co$_{2}$ molecule, that
is, there exist 6 parallel spin electrons in a Co$_{2}$ molecule. The
number of non-conjugated electrons is the greatest. These electrons
occupy different spacial orbitals so that the energy of the Co$_{2}$
molecule is minimized. It can be concluded that the effect of
parallel spin in the Co$_{2}$ molecule is larger than the effect of
the conjugated molecule, which is obviously related to the effect of
electron d delocalization. In addition, the Murrell--Sorbie potential
functions with the parameters for the ground state and the other
states of the Co$_{2}$ molecule are derived. The dissociation energy
$De$ for the ground state of Co$_{2}$ molecule is 4.0489eV,
equilibrium bond length $R_{\rm e}$ is 0.2061~nm, and vibration
frequency $\omega _\e $ is 378.13~cm$^{ - 1}$. Its diatomic molecule
force constants $f_2$, $f_3$, and $f_4$ are 2.4824~aJ$\cdot$nm$^{ -
2}$, -7.3451~aJ$\cdot$nm$^{ - 3}$, and 11.2222~aJ$\cdot$nm$^{ - 4
}$respectively(1~aJ=$10^{-18}$~J). The other spectroscopic data for
the ground state of Co$_{2}$ molecule $\omega_{\e}\chi _{\e}$,
$B_{\e}$, and $\alpha_{\e}$ are 0.7202~cm$^{-1}$, 0.1347~cm$^{-1 }$,
and 2.9120$\times $ 10$^{-1}$~cm$^{-1}$ respectively. And
$\omega_{\e}\chi _{\e}$ is the non-syntonic part of frequency,
$B_{\e}$ is the rotational constant, $\alpha_{\e}$ is revised
constant of rotational constant for non-rigid part of Co$_2$
molecule.

Polymers are a kind of attractive hosts for laser dyes due to their
high transparency in both pumping and lasing ranges and superior
optical homogeneity. In this paper solid dye samples based on
polymethyl methacrylate (PMMA) doped with different concentrations of
1, 3, 5, 7, 8 -pentamethyl-2, 6-diethylpyrromethene-BF$_{2 }$ (PM567)
are prepared. The absorption, fluorescence and lasing spectra of the
samples are obtained. Wide absorption and fluorescence bands are
obtained and a red shift of the maxima of the lasing emission spectra
is observed. With the second-harmonic generation of Q-switched Nd:YAG
laser (532\,nm, $\sim $20\,ns) pumping the samples longitudinally,
the slope efficiencies of the samples are obtained. There is an
optimal dye concentration for the highest slope efficiency when the
pumping energy is lower than some typical value ($\sim $250\,mJ), and
the highest slope efficiency 35.6{\%} is obtained in the sample with
a dye concentration of $2\times10^{ - 4}$\,mol/L. Pumping the samples
at a rate of 10Hz with a pulse energy as high as 200\,mJ (the fluence
is 0.2\,J/cm$^{2})$, the output energy drops to one-half of its
initial value after approximate 15500 pulses and the normalized
photostability is 5.17\,GJ/mol. A kind of solid dye laser which could
have some applications is built.

We investigate the preparation and the control of entangled
states in a system with the two-mode coherent fields interacting
with a moving two-level atom via the two-photon transition. We
discuss entanglement properties between the two-mode coherent
fields and a moving two-level atom by using the quantum reduced
entropy, and those between the two-mode coherent fields by using
the quantum relative entropy. In addition, we examine the
influences of the atomic motion and field-mode structure
parameter $p$ on the quantum entanglement of the system. Our
results show that the period and the duration of the prepared
maximal atom-field entangled states and the frequency of maximal
two-mode field entangled states can be controlled, and that a
sustained entangled state of the two-mode field, which is
independent of atomic motion and the evolution time, can be
obtained, by choosing appropriately the parameters of atomic
motion, field-mode structure, initial state and interaction time
of the system.

Based on the atom--cavity--field interaction, this paper proposes a
scheme for the teleportation of a bipartite entangled coherent state
(ECS) with high fidelity as long as $\left| \alpha \right|$ is not
too small. In this proposal, only four cavities and a three-level
cascade atom are needed. The fidelity of the ECS is calculated and
analysed in detail.

Based on the quantum information theory, this paper has investigated
the entanglement properties of a system which is composed of the two
entangled two-level atoms interacting with the two-mode entangled
coherent fields. The influences of the strength of light field and
the two parameters of entanglement between the two-mode fields on
the field entropy and on the negative eigenvalues of partial
transposition of density matrix are discussed by using numerical
calculations. The result shows that the entanglement properties in a
system of a pairwise entangled states can be controlled by
appropriately choosing the two parameters of entanglement between
the two-mode entangled coherent fields and the strength of two light
fields respectively.

The properties of the field quantum entropy evolution in a system of
a single-mode squeezed coherent state field interacting with a
two-level atom is studied by utilizing the complete quantum theory,
and we focus our attention on the discussion of the influences of
field squeezing parameter $\gamma $, atomic distribution angle
$\theta $ and coupling strength $g$ between the field and the atom
on the properties of the evolution of field quantum entropy. The
results obtained from numerical calculation indicate that the
amplitude of oscillation of field quantum entropy evolution
decreases with the increasing of squeezing parameter $\gamma $, and
that both atomic distribution angle $\theta $ and coupling strength
$g$ between the field and the atom can influence the periodicity of
field quantum entropy evolution.

We present a novel four-mirror cavity with two active gains to
combine power intracavity and also give a detailed theoretical
analysis of the combined gain. By using the effective field method,
the four-mirror cavity with two gain media can be regarded as a
linear resonator with one effective combined gain (ECG), and we
procure a theoretical model of the ECG and deduce its exact
analytical expression. When the two branch gains are close to each
other, the combined gain can be reduced to their product, and the
simplified presentation of ECG has been demonstrated. The combined
output power which directly reflects the small signal ECG of the
four-mirror cavity is studied experimentally, and the results are in
good agreement with the theoretical ones.

All-optical XNOR and AND logic gates using four-wave mixing (FWM) and
cross-gain modulation (XGM) in a single semiconductor optical
amplifier (SOA) with improved dynamics are simultaneously realized.
By numerical simulation, the effects of the input optical wave powers
and injection current on the critical factors of the logic gate
performances, such as the ON--OFF contrast ratio, the power-output
level of the logic `1', and the difference between power outputs of
the logic `1', are investigated in detail. In addition, the effect of
the counter-propagating CW pump on the gain recovery is analysed.

PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES

The evolution of shock waves produced by 7 ns laser pulses in air is
investigated by time-resolved shadowgraph. A nodular structure of
the shock wave is observed. It is found that the origin of the
structure is the multi-longitudinal-microfocus caused by the
astigmatism of the laser beam. The spherical shock waves formed by
each microfocus expand gradually and collide with each other,
resulting in the nodular structure of the shock wave.

In this paper, we show theoretically and experimentally that the large-area
planar plasma with high density and good uniformity can be sustained
by a
surface microwave when the electron density
is over-dense. From the
experimental results we find that the nonuniformities in azimuthal plasma
density and electron temperature have been greatly improved and in particular the
nonuniformity is less than 10{\%} when the gas pressure is 30 Pa.
By improving the antenna shape, enhancing the microwave power and choosing
the appropriate gas pressure, the large area planar plasma with high density
can be produced.

Artificial neural networks are trained to forecast the plasma
disruption in HL-2A tokamak. Optimized network architecture is obtained.
Saliency analysis is made to assess the relative importance of different
diagnostic signals as network input. The trained networks can successfully
detect the disruptive pulses of HL-2A tokamak. The results obtained show the
possibility of developing a neural network predictor that intervenes well in
advance for avoiding plasma disruption or mitigating its effects.

Non-local electron transport in laser-produced plasmas under inertial
confinement fusion (ICF) conditions is studied based on Fokker-Planck
(FP) and hydrodynamic simulations. A comparison between the classical
Spitzer--H\"arm (SH) transport model and non-local transport models
has been made. The result shows that among
those non-local models the Epperlein and Short (ES) model of heat flux is in reasonable agreement with the
FP simulation in overdense region. However, the non-local models are
invalid in the hot underdense plasmas. Hydrodynamic simulation is
performed with the flux limiting model and the non-local model,
separately. The simulation results show that in the underdense
region of the laser-produced plasmas the temperature given by the
flux limiting model is significantly higher than that given with the
non-local model.

CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES

A molecular dynamics simulation study has been performed for the
microstructure evolution in a liquid metal Ni system during
crystallization process at two cooling rates by adopting the
embedded atom method (EAM) model potential. The bond-type index
method of Honeycutt--Andersen (HA) and a new cluster-type index
method (CTIM-2) have been used to detect and analyse the
microstructures in this system. It is demonstrated that the cooling
rate plays a critical role in the microstructure evolution: below the
crystallization temperature $T_{\rm c}$, the effects of cooling rate
are very remarkable and can be fully displayed. At different cooling
rates of $2.0\times10^{13}$\,K\,$\cdot$\,s$^{-1}$ and
$1.0\times10^{12}$\,K\,$\cdot$\,s$^{-1}$, two different kinds of
crystal structures are obtained in the system. The first one is the
coexistence of the hcp (expressed by (12 0 0 0 6 6) in CTIM-2) and
the fcc (12 0 0 0 12 0) basic clusters consisting of 1421 and 1422
bond-types, and the hcp basic cluster becomes the dominant one with
decreasing temperature, the second one is mainly the fcc (12 0 0 0 12
0) basic clusters consisting of 1421 bond-type, and their
crystallization temperatures $T_{\rm c}$ would be 1073 and 1173\,K,
respectively.

A new super-junction lateral double diffused MOSFET (LDMOST)
structure is designed with n-type charge
compensation layer embedded in the p$^{ - }$-substrate near the drain to
suppress substrate-assisted depletion effect that results
from the compensating charges imbalance between the pillars in the n-type buried
layer. A high
electric field peak is introduced in the surface by the pn junction
between the
p$^{ - }$-substrate and n-type buried layer, which given rise to a more uniform
surface electric field distribution by modulation effect. The effect of
reduced bulk field (REBULF) is introduced to improve the vertical breakdown voltage by reducing
the high bulk electric field around the drain. The new structure features
high breakdown voltage, low on-resistance and charges balance in the drift
region due to n-type buried layer.

This paper studies the total ionizing dose radiation effects on MOS
(metal-oxide-semiconductor) transistors with normal and enclosed gate
layout in a standard commercial CMOS (compensate MOS) bulk process.
The leakage current, threshold voltage shift, and transconductance of
the devices were monitored before and after $\gamma $-ray
irradiation. The parameters of the devices with different layout
under different bias condition during irradiation at different total
dose are investigated. The results show that the enclosed layout not
only effectively eliminates the leakage but also improves the
performance of threshold voltage and transconductance for NMOS
(n-type channel MOS) transistors. The experimental results also
indicate that analogue bias during irradiation is the worst case for
enclosed gate NMOS. There is no evident different behaviour observed
between normal PMOS (p-type channel MOS) transistors and enclosed
gate PMOS transistors.

By taking the influence of optical phonon modes into account, this paper
adopts the dielectric continuum phonon model and force balance equation
to investigate the electronic mobility parallel to the interfaces for
AlAs/GaAs semiconductor quantum wells (QWs) under hydrostatic
pressure.
The scattering
from confined phonon modes, interface phonon modes and half-space
phonon modes are analysed and the dominant scattering mechanisms in
wide and narrow QWs are presented. The temperature dependence of the
electronic mobility is also studied in the temperature range of
optical phonon scattering being available. It is shown that the
electronic mobility reduces obviously as pressure increases from 0 to
4GPa, the confined longitudinal optical (LO) phonon modes play an
important role in wide QWs, whereas the interface optical
phonon modes are dominant in
narrow QWs, the half-space LO phonon modes hardly influence the electronic
mobility expect for very narrow QWs.

The phase transitions of semiconductor GaN from the Wurtzite (WZ)
structure and the zinc-blende (ZB) structure to the rocksalt (RS)
structure are investigated by using the first-principles plane-wave
pseudopotential density functional method combined with the
ultrasoft pseudopotential scheme in the generalized gradient
approximation (GGA) correction. It is found that the phase
transitions from the WZ structure and the ZB structure to the RS
structure occur at pressures of 46.1 GPa and 45.2 GPa, respectively.
The lattice parameters, bulk moduli and their pressure derivatives of
these structures of GaN are
also calculated. Our results are consistent with available
experimental and other
theoretical results. The dependence of the normalized formula-unit volume
$V/V_{0 }$ on pressure $P$ is also successfully obtained.

Non-equilibrium molecular dynamics simulations have been performed to
investigate the effect of the cross-section shape on the thermal
conductivity of argon nanowires. Some typical cross-section shapes,
such as triangle, square, pentagon, hexagon and circle, are carefully
explored. The simulation results show that with the same
cross-sectional area of the regular polygons, the thermal
conductivities decrease with the reduction of the sides of the
polygons, and the thermal conductivity of the circular nanowire is
larger than those of the other polygonal ones. Phonon gas kinetic
theory is used to analyse the phonon transport in nanowires, and the
concept of equivalent diameter is proposed to illustrate the
characteristic dimension of the none-circular cross-section.

The lattice parameter, bulk modulus and its pressure derivative of
the wurtzite-type aluminium nitride (w-AlN) are investigated by using
the Cambridge Serial Total Energy Package (CASTEP) program in the
framework of Density Functional Theory (DFT). The calculated results
are in good agreement
with the available experimental data and other theoretical results.
Through the quasi-harmonic Debye model, the dependences of the
normalized lattice parameters $a/a_{0}$ and $ c/c_{0}$, axial ratio
$c/a$, normalized primitive-cell volume $V/V_{0}$, Debye
temperature ${\it\Theta} _{\rm D} $ and heat capacity $C_{\rm V}$ on
pressure $P $ and temperature $ T$ are obtained. It is found that the
interlayer covalent interactions (Al-N bonds) are more (even a
little) sensitive to temperature and pressure than intralayer ones
(N--N bonds), which gives rise to a little lattice anisotropy in the
w-AlN.

A novel method, pulsed laser arc deposition combining the advantages
of pulsed laser deposition and cathode vacuum arc techniques, was
used to deposit the diamond-like carbon (DLC) nanofilms with
different thicknesses. Spectroscopic ellipsometer, Auger electron
spectroscopy, x-ray photoelectron spectroscopy, Raman spectroscopy,
atomic force microscopy, scanning electron microscopy and
multi-functional friction and wear tester were employed to
investigate the physical and tribological properties of the deposited
films. The results show that the deposited films are amorphous and
the sp$^{2}$, sp$^{3}$ and C--O bonds at the top surface of the films
are identified. The Raman peak intensity and surface roughness
increase with increasing film thickness. Friction coefficients are
about 0.1, 0.15, 0.18, when the film thicknesses are in the range of
17--21~nm, 30--57~nm, 67--123~nm, respectively. This is attributed to
the united effects of substrate and surface roughness. The wear
mechanism of DLC films is mainly abrasive wear when film thickness
is in the range of 17--41~nm, while it transforms to abrasive
and adhesive wear, when the film thickness lies between 72 and 123~nm.

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

With the help of ab initio full-potential linearized augmented plane wave
(FPLAPW) method, calculating the electronic structure and linear optical
properties is carried out for $X$Cd$_{2}$(SO$_4$)$_{3}$ ($X=$Tl, Rb). The results show
that Tl$_{2}$Cd$_{2}$(SO$_4$)$_{3}$ (TlCdS) has a larger
band gap than Rb$_{2}$Cd$_{2}$(SO$_4$)$_{3}$ (RbCdS) and the energy bands for
RbCdS are more dispersive than those of TlCdS. From their partial densities
of states (PDOS), we have observed that the hybridization between S ionic 2p and
O atomic 2p orbitals forms SO$_{4}$ ionic groups. The remarkable difference
between RbCdS and TlCdS is, however, the degree of hybridization between
cation (Tl and Rb) and its surrounding oxygen atoms. In the view of quantum
chemistry, the strong p-d hybridization indicates the existence of their
cation ionic bonds (Cd-O, Rb-O, and Tl-O). The
calculations of TlCdS and RbCdS show their optical
properties to be less anisotropic. Their
anisotropies in the optical properties mainly occur in a low photon energy
region of 5--16 eV.

In the framework of density functional theory, using the plane-wave
pseudopotential method, the nitrogen vacancy ($V_{\rm N})$ in both
wurtzite and zinc-blende AlN is studied by the supercell approach.
The atom configuration, density of states, and formation energies of
various charge states are calculated. Two defect states are
introduced by the defect, which are a doubly occupied single state
above the valance band maximum (VBM) and a singly occupied triple
state below the conduction band minimum (CBM) for wurtzite AlN and
above the CBM for zinc-blende AlN. So $V_{\rm N}$ acts as a deep
donor in wurtzite AlN and a shallow donor in zinc-blende AlN. A
thermodynamic transition level $E({3 + } \mathord{\left/ {\vphantom
{{3 + } + }} \right. \kern-\nulldelimiterspace} + )$ with very low
formation energy appears at 0.7 and 0.6eV above the VBM in wurtzite
and zinc-blende structure respectively, which may have a wide shift
to the low energy side if atoms surrounding the defect are not fully
relaxed. Several other transition levels appear in the upper part of
the bandgap. The number of these levels decreases with the structure
relaxation. However, these levels are unimportant to AlN properties
because of their high formation energy.

The anisotropic properties of 1{T}-
and 2{H}-TaS$_{2}$ are investigated by the density functional theory
within the framework of full-potential linearized augmented plane wave
method.
The band structures of 1{T}- and 2{H}-TaS$_{2}$ exhibit anisotropic
properties and the calculated electronic specific-heat coefficient $\gamma$ of
2{H}-TaS$_{2}$ accords well with the existing experimental value.
The anisotropic frequency-dependent
dielectric functions including the effect of the Drude term are analysed, where the
$\varepsilon^{xx}(\omega)$ spectra corresponding
to the electric field ${\bm E}$
perpendicular to the ${z}$ axis show
excellent agreement with the measured results
except for the $\varepsilon_{1}^{xx}(\omega)$ of 1{T}-TaS$_{2}$ below the energy
level of 2.6 eV which is due to the lack of the enough CDW information
for reference
in our calculation.
Furthermore, based
on the values of optical effective mass ratio \emph{P} of 1{T} and 2{H} phases
it is found
that the anisotropy in 2{H}-TaS$_{2}$ is stronger than that in 1{T}-TaS$_{2}$.

The electronic structures and optical properties of B3 ZnO series of
Zn$_{4}$$X_{4-y}M_{y}$($X=$O, S, Se or Te; $M=N$, Sb, Cl or I; $y=0$
or 1) are studied by first-principles calculations using a
pseudopotential plane-wave method. The results show that Zn d-$X$ p
orbital interactions play an important role in the p-type doping
tendency in zinc-based II-VI semiconductors. In Zn$X$, with
increasing atomic number of $X$, Zn d-$X$ p orbital interactions
decrease and Zn s-$X$ p orbital interactions increase. Additionally,
substituting group-V elements for $X$ will reduce the Zn d-$X$ p
orbital interactions while substituting group-VII elements for $X$
will increase the Zn d-$X$ p orbital interactions. The results also
show that group-V-doped Zn$X$ and group-VII-doped Zn$X$ exhibit
different optical behaviours due to their different orbital
interaction effects.

A physical model for mobility degradation by interface-roughness scattering
and Coulomb scattering is proposed for SiGe p-MOSFET with a high-$k$
dielectric/SiO$_{2}$ gate stack. Impacts of the two kinds of scatterings on
mobility degradation are investigated. Effects of interlayer (SiO$_{2})$
thickness and permittivities of the high-$k$ dielectric and interlayer on
carrier mobility are also discussed. It is shown that a smooth interface
between high-$k$ dielectric and interlayer, as well as moderate permittivities
of high-$k$ dielectrics, is highly desired to improve carriers mobility while
keeping a low equivalent oxide thickness. Simulated results agree reasonably
with experimental data.

The feature of conduction band (CB) of Tensile-Strained
Si(TS-Si) on a relaxed Si$_{1 - x}$Ge$_{x}$ substrate is systematically investigated,
including the number of equivalent CB edge energy extrema, CB
energy minima,
the position of the extremal point, and effective mass. Based on an analysis
of symmetry under strain, the number of equivalent CB edge energy extrema is
presented; Using the K$\cdot$P method with the help of perturbation theory, dispersion
relation near minima of CB bottom energy, derived
from the linear deformation potential
theory, is determined, from which the parameters, namely, the
position of the extremal point, and the longitudinal and transverse masses
($m_{\rm l}^{\ast }$ and $m_{\rm t}^{\ast })$ are obtained.

The internal energy and specific heat of a Heisenberg ferro-
antiferromagnetic double-layer system are studied by using spin-wave theory
and the retarded Green function method at low temperatures.
Numerical results show that the antiferromagnetic intralayer coupling
$J_2 $ has an important influence on internal energy and specific
heat for a four-sublattice system with antiferromagnetic (or
ferrimagnetic) interlayer couplings.

Nanocrystalline Ni$_{0.5}$Zn$_{0.5}$ ferrite with average grain sizes
ranging from 10 to 100~nm is prepared by using a
spraying--coprecipitation method. The results indicate that the
nanocrystalline Ni$_{0.5}$Zn$_{0.5}$ ferrite is ferromagnetic without
the superparamagnetic phenomenon observed at room temperature.
Specific saturation magnetization of nanocrystalline
Ni$_{0.5}$Zn$_{0.5}$ ferrite increases from 40.2 to 75.6 emu/g as
grain size increases from 11 to 94nm. Coercivity of nanocrystalline
Ni$_{0.5}$Zn$_{0.5}$ ferrite increases monotonically when $d <
62$~nm.The relationship between the coercivity and the mean grain
size is well fitted into a relation $H_{\rm c }\sim d^{3}$. A
theoretically evaluated value of the critical grain size is 141nm
larger than the experimental value 62nm for nanocrystalline
Ni$_{0.5}$Zn$_{0.5}$ ferrite. The magnetic behaviour of
nanocrystalline Ni$_{0.5}$Zn$_{0.5}$ ferrite may be explained by
using the random anisotropy theory.

Magnetic properties and magnetocaloric effect in TbCo$_{2 - x}$Fe$_{x}$
compounds are studied by DC magnetic measurement. With increasing content of
Fe, the entropy changes decrease slightly, though the Curie
temperature is
tuned from 231 K ($x=0$) to 303 K ($x=0.1$). Magnetic entropies of TbCo$_{2}$
compound are calculated by using mean field approximation (MFA). Results
estimated by using Maxwell relation are consistent with that of MFA
calculation. It is shown that the entropy changes are mainly derived from
the magnetic entropy changes. The lattice has almost no contribution to the
entropy change in the vicinity of phase transition.

Magnetic properties and magnetic entropy changes in
LaFe$_{11.5}$Si$_{1.5}$ have been investigated by partially
substituting Pr by La. It is found that La$_{1 -
x}$Pr$_{x}$Fe$_{11.5}$Si$_{1.5}$ compounds remain cubic
NaZn$_{13}$-type structures even when the Pr content is increased to
0.5, i.e. $x = 0.5$. Substitution of Pr for La leads to a reduction
in both the crystal constant and the Curie temperature. A stepwise
magnetic behaviour in the isothermal magnetization curves is
observed, indicating that the characteristic of the itinerant
electron metamagnetic (IEM) transition above T_{C} becomes more
prominent with the Pr content increasing. As a result, the magnetic
entropy change is remarkably enhanced from 23.0 to 29.4\,J/kg$\cdot$K
as the field changes from 0 to 5\,T, with the value of $x$ increasing
from 0 to 0.5. It is more attractive that the magnetic entropy
changes for all samples are shaped into high plateaus in a wide range
of temperature, which is highly favourable for Ericsson-type magnetic
refrigeration.

Magnetic properties and magnetocaloric effects of Tb_{6}Co_{1.67}Si_{3} have been investigated by magnetization measurement. This compound is of a hexagonal Ce_{6}Ni_{2}Si_{3}-type structure with a saturation magnetization of 187emu/g at 5K and a reversible second-order magnetic transition at Curie temperature T_{C}= 186K. A magnetic entropy change \Delta S = 7J.kg^{-1}.K^{-1} is observed for a magnetic field change from 0 to 5. A large value of refrigerant capacity (RC) is found to be 330J/kg for fields ranging from 0 to 5T. The large RC, the reversible magnetization around T_{C} and the easy fabrication make the Tb_{6}Co_{1.67}Si_{3} compound a suitable candidate for magnetic refrigerants in a corresponding temperature range.

The influences of Dzyaloshinskii--Moriya (DM) interaction and Kaplan--Shekhtman--Entinwohlman--Aharony (KSEA) interaction on the dimerization of a spin-Peierls system are investigated theoretically by using the Lanczos numerical method. The ground state of the spin-Peierls system is still dimerized phase when both of the DM and the KSEA interactions have the same value with Heisenberg interaction. It is found that the KSEA interaction and uniform DM interaction are always against systemic dimerization, but the staggered DM interaction acts in favour of dimerization. Furthermore, the influences of the DM and the KSEA interactions are also studied in terms of the ground state index rate and the energy gap index rate of the dimerized Heisenberg system. The results show that the DM interaction makes the index rates larger, while the KSEA interaction makes them smaller.

Electronic and magnetic properties of Fe_{1 - x }Co_{x}Si alloys
were investigated by using a full-potential linear
augmented-plane-wave method based on density functional theory.
Electronic structure calculation demonstrates that half-metallic
property appears in the Fe-rich region of 0 < x \le 0.25, while the
alloys turn out to be a magnetic metal for x > 0.25. The
concentration dependence of the magnetic moment of the alloys can be
understood by the fixed Fermi level at minority band in Fe-rich
region, as well as at the majority band in Co-rich region. In Fe-rich
alloys, the electronic structure and the magnetic properties at Fe
site depend mainly on the spin-polarization of nearest neighbouring
Co atoms, while in Co-rich alloys, these features at Co site arise
mainly from the neighbours of Fe atoms.

This paper has systematically investigated the substrate temperature and
thickness dependence of surface morphology and magnetic property of CrAs
compound films grown on GaAs by molecular-beam epitaxy. It finds that the
substrate temperature affects the surface morphology and magnetic property
of CrAs thin film more potently than the thickness.

Considering two beams propagate in semiconductor crystal, this paper
discusses the polarization dependence of pump beam-induced intensity attenuation of
probe beam due to two-photon absorption (TPA). Numerical calculation
and experimental measurement demonstrate that TPA coefficient is
polarization dependent. For homogeneous materials, probe beam
attenuation arises from the imaginary part of diagonal and
off-diagonal components of third-order nonlinear susceptibilities.

Hawking radiation is viewed as a tunnelling process. In this way the
emission rates of massless particles and massive particles tunnelling
across the event horizon of general stationary axisymmetric black
holes are calculated, separately. The emission spectra of these two
different kinds of outgoing particles have the same functional form
and both are consistent with an underlying unitary theory.

[an error occurred while processing this directive]