This paper presents a scheme for quantum secure direct communication
with quantum encryption. The two authorized users use repeatedly a
sequence of the pure entangled pairs (quantum key) shared for
encrypting and decrypting the secret message carried by the
travelling photons directly. For checking eavesdropping, the two
parties perform the single-photon measurements on some decoy
particles before each round. This scheme has the advantage that the
pure entangled quantum signal source is feasible at present and any
eavesdropper cannot steal the message.

Based on the total time derivative along the trajectory of the
time, we study the unified symmetry of Vacco dynamical systems.
The definition and the criterion of the unified symmetry for the
system are given. Three kinds of conserved quantities, i.e. the
Noether conserved quantity, the generalized Hojman conserved
quantity and the Mei conserved quantity, are deduced from the
unified symmetry. An example is presented to illustrate the
results.

In this paper, the improved Jacobian elliptic function expansion
approach is extended and applied to constructing discrete solutions
of the semi-discrete coupled modified Korteweg de Vries (mKdV)
equations with the aid of the symbolic computation system Maple.
Some new discrete Jacobian doubly periodic solutions are obtained.
When the modulus $m \rightarrow 1$, these doubly periodic solutions
degenerate into the corresponding solitary wave solutions, including
kink-type, bell-type and other types of excitations.

An extended Boussinesq equation that models weakly nonlinear and
weakly dispersive waves on a uniform layer of water is studied in
this paper. The results show that the equation is not
Painlev\'e-integrable in general. Some particular exact travelling
wave solutions are obtained by using a function expansion method. An
approximate solitary wave solution with physical significance is
obtained by using a perturbation method. We find that the extended
Boussinesq equation with a depth parameter of $1/\sqrt 2$ is able to
match the Laitone's (1960) second order solitary wave solution of
the Euler equations.

On the basis of the acoustoelastic theory for elastic--plastic
materials, the influence of statically deformed states including both
the elastic and plastic deformations induced by applied uniaxial
stresses on the Rayleigh wave in layered rocks is investigated by
using a transfer matrix method. The acoustoelastic effects of
elastic--plastic strains in rocks caused by static deformations, are
discussed in detail. The Rayleigh-type and Sezawa modes exhibit
similar trends in acoustoelastic effect: the acoustoelastic effect
increasing rapidly with the frequency-thickness product and the phase
velocity change approaching a constant value for thick layer and high
frequency limit. Elastic--plastic deformations in the Castlegate
layered rock obviously modify the phase velocity of the Rayleigh wave
and the cutoff points for the Sezawa modes. The investigation may be
useful for seismic exploration, geotechnical engineering and
ultrasonic detection.

We consider the problem of trying to send a single classical bit
through an amplitude-damping channel when two transmissions through
the channel are available as a resource. It is demonstrated that two
entangled transmissions can enhance the receiver's capability of
making a correct inference under certain conditions compared with two
product-state transmissions.

In this paper a controlled quantum teleportation scheme of an
N-particle unknown state is proposed when N groups of
three-particle W_{1} states are utilized as quantum channels.
The quantum information of N-particle unknown state is
transmitted from the sender to the recipient under the control
of all supervisors. It can be realized with a certain
probability. After the sender makes Bell-state measurements and
the supervisors perform the computational basis measurements,
the recipient will introduce auxiliary particles and carry out
unitary transformations depending on classical information from
the sender and the supervisors. Finally, the computational basis
measurement will be performed by the recipient to confirm
whether the teleportation succeeds or not. The successful
completion of the scheme relies on all supervisors' cooperation.
In addition, the fidelity and security of the scheme are
discussed.

We consider how to teleport two- and three-mode
Einstein--Podolsky--Rosen entangled states (|\eta> and |
p_{t},\chi_{2},\chi_{3}>) via a |
p_{t},\chi_{2},\chi_{3}> quantum channel for continuous
variables. Using the complete and orthogonal representation of the
entangled states, we can not only find the a complete basis set for
the joint measurement but also propose the specific scheme of
teleportation. Our calculation can be greatly simplified by using
their Schmidt decompositions.

This paper proposes a simple scheme for generating a three-atom GHZ
state via cavity quantum electrodynamics (QED). The task can be
achieved through the interaction between two EPR states, which can be
prepared easily with current technology. In this scheme, the cavity
field is only virtually excited during the interaction process, and
no quantum information transfer between the atoms and the cavity is
required. Thus it greatly prolongs the efficient decoherent time.
Moreover, this scheme is also applicable for generating an N-atom
GHZ state.

An efficient quantum key distribution (QKD) protocol with orthogonal
product states in the 3 \otimes 3 Hilbert space is presented. The
sender, Alice, disorders the orthogonal product state sequence and
sends it to Bob. After Alice has published the matching information
of the particle sequence, Bob recovers the correct correspondences
and makes an orthogonal measurement on the orthogonal product states
to obtain the information sent by Alice. Finally, security analysis
is also made.

We propose a scheme for the preparation of one-dimensional and
two-dimensional cluster states by using hot trapped ions. The scheme
is based on the interaction between two ions and bichromatic
radiation. The vibrational mode in our protocol is only virtually
excited so that the system is insensitive to the thermal field. In
addition, we only use two levels of ions as qubits and the
successful probability may achieve 100%.

We propose feasible experimental schemes for preparing all
five-photon graph states. Our schemes require only linear optical
elements, photon detectors and post-selection, which are available
in current experiment so that these schemes are within the reach of
the current technology.

The entanglement in an anisotropic spin-1 Heisenberg chain with a
uniform magnetic field is investigated. The ground-state entanglement
will undergo two different kinds of transitions when the anisotropy
\Delta and the amplitude of the magnetic field B are varied.
The thermal entanglement of the nearest neighbour always declines
when B increases no matter what the value of the anisotropy is. It
is very interesting to note that the entanglement of the next-nearest
neighbour can increase to a maximum at a certain magnetic field.
Regardless of the boundary condition, the nearest-neighbour
entanglement always decreases and approaches to a constant value when
the size of the system is very large. The constant value of open
boundary condition is much larger than that of periodic boundary
condition.

The performances of a two-mode Gaussian state under parametric
amplification, symmetric amplitude damping and thermal noise are
studied. The time-dependent complex correlation matrix of the state
in evolution is given. The separability of the final two-mode
Gaussian state is examined under symmetric amplification and
asymmetric amplification separately.

For a Bose--Einstein condensate (BEC) confined in a double lattice
consisting of two weak laser standing waves we find the Melnikov
chaotic solution and chaotic region of parameter space by using the
direct perturbation method. In the chaotic region, spatial evolutions
of the chaotic solution and the corresponding distribution of
particle number density are bounded but unpredictable between their
superior and inferior limits. It is illustrated that when the
relation k_{1}\approx k_{2} between the two laser wave vectors is
kept, the adjustment from k_{2}1 to k_{2}\ge k_{1} can
transform the chaotic region into regular one or the other way round.
This suggests a feasible scheme for generating and controlling chaos,
which could lead to an experimental observation in the near future.

Chaos-based encryption schemes have been studied extensively,
while the security analysis methods for them are still problems
to be resolved. Based on the periodic orbit theory, this paper
proposes a novel security analysis method. The periodic orbits
theory indicates that the fundamental frequency of the spiraling
orbits is the natural frequency of associated linearized system,
which is decided by the parameters of the chaotic system. Thus,
it is possible to recover the plaintext of secure communication
systems based on chaotic shift keying by getting the average
time on the spiraling orbits. Analysis and simulation results
show that the security analysis method can break chaos shift
keying secure communication systems, which use the parameters as
keys.

In this paper multiple delay feedback control (MDFC) with different
and independent delay times is shown to be an efficient method for
stabilizing fixed points in finite-dimensional dynamical systems.
Whether MDFC can be applied to infinite-dimensional systems has been
an open question. In this paper we find that for infinite-dimensional
systems modelled by delay differential equations, MDFC works well for
stabilizing (unstable) steady states in long-, moderate- and
short-time delay regions, in particular for the hyperchaotic case.

The chaos in the KdV Burgers equation describing a ferroelectric
system has been successfully controlled by using a continuous
feedback control. This system has two stationary points. In order to
know whether the chaos is controlled or not, the instability of
control equation has been analysed numerically. The numerical
analysis shows that the chaos can be converted to one point by using
one control signal, however, it can converted to the other point by
using three control signals. The chaotic motion is converted to two
desired stationary points and periodic orbits in numerical experiment
separately.

The impulsive control of chaotic systems, which are subjected to
unbounded exogenous perturbations, is considered. By using the
theory of impulsive differential equation together with the fuzzy
control technique, the authors propose an impulsive robust chaos
controlling criterion expressed as linear matrix inequalities
(LMIs). Based on the proposed control criterion, the procedure for
designing impulsive controllers of common (perturbed) chaotic
systems is provided. Finally, a numerical example is given to
demonstrate the obtained theoretical result.

Based on a modified Lorenz system, a relatively simple
four-dimensional continuous autonomous hyperchaotic system is
proposed by introducing a state feedback controller. The system
consists of four coupled first-order ordinary differential equations
with three nonlinear cross-product terms. Some dynamical properties
of this hyperchaotic system, including equlibria, stability, Lyapunov
exponent spectrum and bifurcation, are analysed in detail. Moreover,
an electronic circuit diagram is designed for demonstrating the
existence of the hyperchaos, and verifying computer simulation
results.

Evidence is presented for the nonchaotic random behaviour in a
second-order autonomous deterministic system. This behaviour is
different from chaos and strange nonchaotic attractor. The
nonchaotic random behaviour is very sensitive to the initial
conditions. Slight difference of the initial conditions will
generate wholly different phase trajectories. This random behaviour
has a transient random nature and is very similar to the
coin-throwing case in the classical theory of probability. The
existence of the nonchaotic random behaviour not only can be derived
from the theoretical analysis, but also is proved by the results of
the simulated experiments in this paper.

In this paper, the generation of striped trajectories in phase space
by noise-injection is considered. With suitable amplitudes of noise,
the steady-state system orbits appear in rectangular striped shape.
The relationship between the shape (including the range and the
number of stripes) and some parameters is discussed. The result
shows that noise can also generate the striped shape effectively and
simply, which is similar to the newly-discovered striped pattern
generated by controlled Rossler systems.

A density functional theory (DFT) is used to investigate
molecular orientation of hard rod fluids in a hard slit. The DFT
approach combines a modified fundamental measure theory (MFMT)
for excluded-volume effect with the first order thermodynamics
perturbation theory for chain connectivity. In the DFT approach,
the intra-molecular bonding orientation function is introduced.
We consider the effects of molecular length (i.e. aspect ratio
of rod) and packing fraction on the orientations of hard rod
fluids and flexible chains. For the flexible chains, the chain
length has no significant effect while the packing fraction
shows slight effect on the molecular orientation distribution.
In contrast, for the hard rod fluids, the chain length
determines the molecular orientation distribution, while the
packing fraction has no significant effect on the molecular
orientation distribution. By making a comparison between
molecular orientations of the flexible chain and the hard rod
fluid, we find that the molecular stiffness distinctly affects
the molecular orientation. In addition, partitioning coefficient
indicates that the longer rodlike molecule is more difficult to
enter the confined phase, especially at low bulk packing
fractions.

In the functional properties of complex networks, modules play a
central role. In this paper, we propose a new method to detect and
describe the modular structures of weighted networks. In order to
test the proposed method, as an example, we use our method to analyse
the structural properties of the Chinese railway network. Here, the
stations are regarded as the nodes and the track sections are
regarded as the links. Rigorous analysis of the existing data shows
that using the proposed algorithm, the nodes of network can be
classified naturally. Moreover, there are several core nodes in each
module. Remarkably, we introduce the correlation function $G_{rs}$,
and use it to distinguish the different modules in weighted networks.

In this paper, surface photovoltage spectroscopy (SPS) is used to
determine the electronic structure of the hydrogenated transition Si
films. All samples are prepared by using helicon wave plasma-enhanced
chemical vapour deposition technique, the films exhibit a transition
from the amorphous phase to the microcrystalline phase with
increasing temperature. The film deposited at lower substrate
temperature has the amorphous-like electronic structure with two
types of dominant defect states corresponding to the occupied Si
dangling bond states (D^{0}/D^{-} and the empty Si dangling
states (D^{+}). At higher substrate temperature, the
crystallinity of the deposited films increases, while their band gap
energy decreases. Meanwhile, two types of additional defect states is
incorporate into the films as compared with the amorphous
counterpart, which is attributed to the interface defect states
between the microcrystalline Si grains and the amorphous matrix. The
relative SPS intensity of these two kinds of defect states in samples
deposited above 300\du increases first and decreases afterwards,
which may be interpreted as a result of the competition between
hydrogen release and crystalline grain size increment with increasing
substrate temperature.

In this paper single ultra-fast voltage pulses are introduced to the
Pt/Ir tip of a scanning tunnelling microscope (STM), and the
non-destructive threshold of the graphite surface is studied
systematically in a wide range of pulse durations (from 10$^{4}$ to
8\,ns). Considering the waveform distortion of the pulses at the
tunnelling region, this paper gives the corrected threshold curve of
pulse amplitude depending on pulse duration. A new explanation of
threshold power has been suggested and fits the experimental results
well.

In-line x-ray phase contrast imaging has attracted much attention due
to two major advantages: its effectiveness in imaging weakly
absorbing materials, and the simplicity of its facilities. In this
paper a comprehensive theory based on Wigner distribution developed
by Wu and Liu [Med. Phys. 31 2378-2384 (2004)] is reviewed. The
influence of x-ray source and detector on the image is discussed.
Experiments using a microfocus x-ray source and a CCD detector are
conducted, which show the role of two key factors on imaging: the
tube voltage and tube current. High tube current and moderate tube
voltage are suggested for imaging.

The fundamental and second order strongly nonlocal solitons of the
nonlocal nonlinear Schr\"{o}dinger equation for several types of
nonlocal responses are calculated by Ritz's variational method. For
a specific type of nonlocal response, the solutions of the strongly
nonlocal solitons with the same beam width but different degrees of
nonlocality are identical except for an amplitude factor. For a
nonlocal case where the nonlocal response function decays in direct
proportion to the $m$th power of the distance near the source point,
the power and the phase constant of the strongly nonlocal soliton are
in inverse proportion to the $(m+2)$th power of its beam width.

The derivations of several conservation laws of the generalized
nonlocal nonlinear Schr?dinger equation are presented. These
invariants are the number of particles, the momentum, the angular
momentum and the Hamiltonian in the quantum mechanical analogy. The
Lagrangian is also presented.

The cross sections for the production of nuclides of element 108 via
hot fusion evaporation reactions are studied using a two-parameter
Smoluchowski equation. The optimal reactions for the synthesis of
new nuclides of element 108 with mass numbers from 266 to 271 are
suggested. The macroscopic-microscopic approach predicts a strong
deformed shell closure at Z \approx 108 and N=162. The synthesis
of more nuclides of element 108 is meaningful to the confirmation of
the existence of this deformed shell closure.

The International Linear Collider (ILC), which is based on
super-conducting RF acceleration technology, requires the damping
rings to provide beams with extremely small equilibrium emittance,
and large acceptance to ensure good injection efficiency for
high-emittance, and high-energy spread beam from the positron source.
In order to reduce the cost for ILC damping rings, an alternative
lattice which is different from the baseline configuration design has
been designed with modified FODO arc cells, and the total quadrupole
number has been reduced by half. At the same time, to decrease the
total cost involved in constructing access shafts needed to supply
power, cryogenics etc. for the wigglers and other systems, the number
of wiggler sections is decreased from 8 to 4, and further to 2. This
new lattice has been optimized to have a good dynamic aperture. This
alternative ILC damping ring lattice design will reduce the cost
largely as compared with the baseline design.

In this paper, the dynamics of coherent laser control of potassium
atoms is studied by using the time-dependent multilevel approach
(TDMA). The calculation results of population transfer are presented
with different laser fields. The results show that the population can
be transferred to target state completely by a specially designed
laser field.

In this paper, the equilibrium geometry, harmonic frequency and
dissociation energy of S_{2}^{-} and S_{3}^{-} have been calculated
at QCISD/6-311++G(3d2f) and B3P86/6-311++G(3d2f) level. The{
}S_{2}^{-} ground state is of ^{-}Pi_{g}, the S_{3}^{-}
ground state is of ^{-}B_{1} and S_{3}^{-} has a bent (C_{2V})
structure with an angle of 115.65℃ The results are in good
agreement with these reported in other literature. For S_{3}^{-}
ion, the vibration frequencies and the force constants have also been
calculated. Base on the general principles of microscopic
reversibility, the dissociation limits has been deduced. The
Murrell--Sorbie potential energy function for S_{2}^{-} has been
derived according to the ab initio data through the least-squares
fitting. The force constants and spectroscopic data for S_{2}^{-}
have been calculated, then compared with other theoretical data. The
analytical potential energy function of S_{3}^{-} have been obtained
based on the many-body expansion theory. The structure and energy can
correctly reappear on the potential surface.

Close-coupling calculations based on an R-matrix formalism are
performed for the 1s--2p resonance photoionizations from the
low-lying states of boron-like carbon ions. The resonance energies,
widths and oscillator strengths of 1s-2p core excitations are
determined by analysing the calculated photoionization cross
sections. Our calculations are in
reasonable agreement with the experimental and
theoretical results presented by other authors. The present numerical values may
help to analyse the astrophysical and laboratory plasmas.

The elastic scattering properties for collisions between cold and
ultracold ^{39}K atoms in a triplet state are investigated. Based on the
recent theoretical and experimental results, the improved hybrid potential
is presented for a triplet a^{3}\Sigma_{u}^{+} ground state of
K_{2}. Our calculated value of the s-wave scattering length a by using
the Numerov method for the triplet state is 79.578a_{0}
and found to be in good agreement with the previous ones. The numbers of
bound states are supported by the molecular potential. Pronounced shape
resonances appear for the l = 3 partial waves for the a^{3}\Sigma_{u}^{+} state. Furthermore, the s-wave scattering cross section, the total cross
section and energy positions of shape resonances for the
a^{3}\Sigma_{u}^{+} state are calculated.

The comparison between single-point energy scanning (SPES) and
geometry optimization (OPT) in determining the equilibrium geometries
of c^{3}\Sigma^{+}_{g} and B^{1}Ⅱ
_{u} states of
dimer ^{7}Li_{2} is made at numerous basis sets by using a
symmetry-adapted-cluster configuration-interaction (SAC-CI) method in
the Gaussian 03 program package. In this paper the difference of the
equilibrium geometries obtained by SPES and by OPT is reported. The
results obtained by SPES are found to be more reasonable than those
obtained by OPT in full active space at the present SAC-CI level of
theory. And the conclusion is attained that the cc-PVTZ is a most
suitable basis set for these states. The calculated dissociation
energies and equilibrium geometries are 0.8818 eV and 0.3090 nm for
c^{3}\Sigma^{+}_{g} state, and 0.3668 eV and 0.2932 nm for
B^{1}Ⅱ
_{u} state respectively. The potential energy curves
are calculated over a wide internuclear distance range from about
2.5a_{0} to 37a_{0} and have a least-squares fit into the
Murrell--Sorbie function. According to the calculated analytic
potential energy functions, the harmonic frequencies (\omega_{e} and other spectroscopic data (\omega_{e} \chi_{e} ,
\B_{e} and \alpha_{e} are calculated. Comparison of
the theoretical determinations at present work with the experiments
and other theories clearly shows that the present work is the most
complete effort and thus represents an improvement over previous
theoretical results.

Chen Lin, Chen Xi-Meng, Shao Jian-Xiong, Lu Yan-Xia, Ding Bao-Wei, Cui Ying, Gao Zhi-Min, Liu Yu-Wen, Du Juan, Xie Jiang-Shan, Sun Guang-Zhi, Liu Zhao-Yuan

Chin. Phys. B 2007, 16 (8): 02378; doi: 10.1088/1009-1963/16/8/037
Full Text: PDF (284KB) (
448
)

In this paper a projectile ions--recoil ions coincidence technique is
employed to investigate the target ionization and projectile charge
state changing processes in the collision of 0.22--6.35 MeVC^{q+}(q = 1-4) ions with argon atoms. The partial cross section
ratios of the double, triple, quadruplicate ionization to the single
ionization (or the single capture) of argon associated with single
electron loss (or single electron capture) by the projectile are
measured and compared with the previous experimental results. In the
present experiment, it is observed that the ratios of ionization
cross sections R associated with single loss and single capture
depend strongly on the projectile charge state and vary significantly
with different reaction channels as impact energy increases. In
addition, this paper gets empirical scaling laws for the ionization
cross section ratios R corresponding to the projectile single loss
and finds that the ratios of the double ionization to the single
ionization associated with single electron capture remain constant in
the present energy range.

Target ionization accompanied with projectile electron loss is
investigated for 0.2--7 MeV C^{q+}(q=1-4) with He and 0.25--5
MeV O^{q+}(q=1-4) with He collisions. For projectile
single-electron loss channel, the He double-to-single ionization
ratio R is nearly independent of projectile charge state but
dependent on the nuclear charge of projectile Z_{p}. The
results are analysed with atomic structure qualitatively. So far
there have not existed the experimental data comparable with our
results, to our knowledge. The ratio $R$ is interpreted in terms of
the two-step mechanism. This analysis agrees well with similar
experiments in the literature.

In this paper a relativistic many-body perturbation calculation is
performed to calculate the hyperfine constants of the ground states
for lithium-like isoelectronic sequence. Zeroth-order hyperfine
constants are calculated with Dirac--Fock wavefunctions, and the
finite basis sets of the Dirac--Fock equations are constructed by B
splines. With the finite basis sets, the core polarization and the
correlation effect are evaluated.

In this paper, possible structures of Ga_{5}P_{5} cluster were
optimized by using density functional method with generalized gradient
correction (B3LYP). The electronic structure of the isomers with lower
energy was studied. The most stable structure obtained for Ga_{5}P_{5}
is a distorted pentaprism. The Ga-P bond formed in the cluster is strongly
ionic. Based on NBO analysis, an average value of 0.59 electron transfers
from Gallium to Phosphorus. The bond length 2.33--2.43{\AA} is around the
value in bulk GaP. The HOMO-LUMO gap is about 2.2 eV. The dipole moment and
polarizability are calculated, and the IR and Raman spectra are also
presented.

We have studied the effect of the spontaneously generated coherence
(SGC) on gain of lasing without inversion (LWI) in a closed
three-level $\Lambda $-type atomic system with Doppler broadening. It
is shown that, regardless of the driving and probe fields being co-
or counter-propagating, at a suitable value of the Doppler width, we
can obtain a much larger LWI gain with SGC than that without SGC; and
the region of the LWI gain spectrum with SGC is obviously larger than
that without SGC. When the Doppler width takes a constant value, the
gain does not monotonically decrease or increase with increasing
strength of SGC, the largest LWI gain can be obtained by adjusting
strength of SGC. Generally speaking, the co-propagating probe and
driving fields is favourable to obtain a larger LWI gain.

Considering two identical two-level atoms interacting
with a single-mode thermal
field through two-photon processes,
this paper studies the atomic coherence control on the
entanglement between two two-level atoms,
and finds that the entanglement is greatly
enhanced due to the initial atomic coherence. The results show
that the entanglement can be manipulated
by changing the initial
parameters of the system, such as the superposition coefficients
and the relative phases
of the initial atomic coherent state and the mean photon
number of the cavity field.

Using the coherent state representation of Wigner operator and the technique
of integration within an ordered product (IWOP) of operators, this
paper derives the Wigner
function for the Hermite polynomial state (HPS). The tomogram of
the HPS is calculated with the aid of newly introduced intermediate
coordinate-momentum representation in quantum optics.

By virtue of the technique of integration within an ordered product (IWOP)
of operators and the properties of the inverses of annihilation and creation
operators of f-oscillator, this paper obtains two new types
of squeezed operators and
f-analogues of squeezed one-photon states, which are quite different from
ones constructed by Song and Fan
({Phys. Lett.} A {294} (2002) 66). Subsequently,
some nonclassical properties of the states are investigated in detail.

This paper obtains the exact analytical solution of atomic
Raman--Nath diffraction in the coordinate representation and
discusses the influence of different initial conditions and detunings
on the atomic spatial population distribution. The phase difference
between the dipole matrix element and initial atomic population may
influence the atomic spatial population distribution after
diffraction, which has never been discussed before as far as we know.
It offers a method to measure the phase by the spatial population
distribution, which is interesting in the study of quantum optics.

For experiments such as on Ni-like Ag x-ray laser, driven by 1\omega
laser, the gain region is only several~nm depth near the target
surface, this paper proposes a new two-layer target, in which a thin
layer (several nm depth) of silver is plated on the surface of some
other materials. Furthermore, the Ni-like Ag 13.9~nm x-ray laser
produced by three new kinds of two-layer target with CH, Al and Ge as
foundation, was theoretically studied.

In most collisional schemes of x-ray laser (XRL) experiments, a
bow-like intensity distribution of XRL is often observed, and it is
generally ascribed to the two-dimensional hydrodynamic behaviour of
expanding plasma. In order to better understand its essence in
physics, a newly developed two-dimensional non-equilibrium radiation
hydrodynamic code XRL2D is used to simulate a quasi-steady state
Ni-like Ag XRL experiment on ShenGuang-II facility. The simulation
results show that the bow-like distribution of Ni-like ions caused by
over-ionization in the central area of plasma is responsible for the
bow-like shape of the XRL intensity distribution observed.

In this paper, the lattice Boltzmann method is applied to simulate a
dumbbell moving in a pressure-driven flow in a planar channel with
the stress-integration method for the evaluation of hydrodynamic
force acting on the cylinders. The simulation results show that the
dumbbell also has the important feature of the Segr\'e--Silberberg
effect like a particle in a Poiseuille flow. The dumbbell
trajectories, orientations, the cylinders vertical velocities and
angular velocities all reach their equilibrium values separately
independent of their initial positions. It is also found that the
dumbbell equilibrium positions depend on the flow Reynolds number,
blockage ratio and elastic coefficient. This study is expected to be
helpful to understand the dynamics of polymer solutions, polymer
synthesis and reaction, etc.

PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES

Under the consideration of non-steady case, a set of equations is
derived, which describes the non-steady nonlinear interactions
between plasma and field in the far wake region of a space vehicle.
Numerical calculations are also made and the numerical results show
that density cavities and electromagnetic solitary waves are
generated due to the modulation instability, if the envelope of high
frequency modulation field is strong enough. This is
of great significance to the detection of disguised space vehicles.

CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES

The diffusion behaviours of vanadium implanted p- and
n-type 4H-SiC are investigated by using the secondary
ion mass spectrometry (SIMS).
Significant redistribution, especially out-diffusion of vanadium towards the
sample surface is not observed after 1650℃ annealing for both p-
and n-type samples. Atomic force microscopy (AFM) is applied to the
characterization of
surface morphology, indicating the formation of continuous long furrows
running in one direction across the wafer surface after 1650℃
annealing. The surface roughness results from the
evaporation and re-deposition of
Si species on the surface during annealing. The chemical compositions of
sample surface are investigated using x-ray photoelectron spectroscopy (XPS).
The results of C 1s and Si 2p core-level spectra are presented in detail to
demonstrate the evaporation of Si from the wafer and the deposition of SiO_{2}
on the sample surface during annealing.

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

Based on the scheme of damped harmonic oscillator quantization and
thermo-field dynamics (TFD), the quantization of mesoscopic damped
double resonance RLC circuit with mutual capacitance--inductance
coupling is proposed. The quantum fluctuations of charge and current
of each loop in a
squeezed vacuum state are studied in the thermal excitation case. It is shown
that the fluctuations not only depend on circuit inherent parameters,
but also rely on excitation quantum number and squeezing parameter.
Moreover, due to the finite environmental temperature and
damped resistance, the fluctuations increase with the temperature rising,
and decay with time.

Single crystals of Te-doped dichalcogenides 2H-NbSe_{2-x}Te_{x}(x = 0, 0.10, 0.20) were grown by vapour transport method. The
effect of Te doping on the superconducting and charge-density wave
(CDW) transitions has been investigated. The sharp decrease of
residual resistance ratio, RRR = R(300K)/R(8K), with increasing
Te content was observed, indicating that the disorder in the
conducting plane is induced by Te doping. Meanwhile the
superconducting transition temperature, T_{c}, decreases
monotonically with Te content. However, the CDW transition
temperature, T_{CDW}, shown by a small jump in the temperature
dependence of the resistivity near 30~K, increases slightly. The
results show that the suppression of superconductivity might be
caused by the enhancement of CDW ordering. The disorder has little
influence on the CDW ordering.

8000 CROSSDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY

Lidar (Light detection and ranging) system monitoring of the
atmosphere is a novel and powerful technique tool. The Raman lidar is
well established today as a leading research tool in the study of
numerous important areas
in the atmospheric sciences. In this paper, the principle of
Raman lidar technique measurement CO_{2} concentration profile is
presented and the errors caused by molecular and aerosol extinction
for CO_{2} concentration profile measurement with Raman lidar are
also presented. The standard atmosphere extinction profile and
`real-time' Hefei area extinction profile are used to conduct
correction and the corresponding results are yielded. Simulation
results with standard atmosphere mode correction indicate that the
errors caused by molecule and aerosol extinction should be counted
for the reason that they could reach about 8 ppm and 5~ppm
respectively. The relative error caused by Hefei area extinction
correction could reach about 6%. The errors caused by the two
components extinction influence could produce significant changes for
CO_{2} concentration profile and need to be counted in data
processing which could improve the measurement accuracies.

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