2,201 research outputs found
Multipole (E1, M1, E2, M2) transition wavelengths and rates between states with n<= 6 in heliumlike carbon, nitrogen, oxygen, neon, silicon, and argon
Transition wavelengths and rates are given for E1, E2, M1, and M2 transitions
between singlet and triplet S, P, D, and F states in heliumlike ions of
astrophysical interest: carbon, nitrogen, oxygen, neon, silicon, and argon. All
possible transitions between states with n <= 6 are considered. Wave functions
and energies are calculated using the relativistic configuration-interaction
(CI) method including both Coulomb and Breit interactions. For transitions to
the ground state, the present theoretical wavelengths agree to five digits with
precise measurements.Comment: 8 pages of text 97 pages of tables submitted to Atomic & Data Nuclear
Datable
The weak localization for the alloy-type Anderson model on a cubic lattice
We consider alloy type random Schr\"odinger operators on a cubic lattice
whose randomness is generated by the sign-indefinite single-site potential. We
derive Anderson localization for this class of models in the Lifshitz tails
regime, i.e. when the coupling parameter is small, for the energies
.Comment: 45 pages, 2 figures. To appear in J. Stat. Phy
Uniqueness of the ground state in the Feshbach renormalization analysis
In the operator theoretic renormalization analysis introduced by Bach,
Froehlich, and Sigal we prove uniqueness of the ground state.Comment: 10 page
In-medium QCD and Cherenkov gluons
The equations of in-medium gluodynamics are proposed. Their classical lowest
order solution is explicitly shown for a color charge moving with constant
speed. For nuclear permittivity larger than 1 it describes emission of
Cherenkov gluons resembling results of classical electrodynamics. The choice of
nuclear permittivity and Lorentz-invariance of the problem are discussed.
Effects induced by the transversely and longitudinally moving (relative to the
collision axis) partons at LHC energies are described.Comment: 13 p., misprints correcte
Stability of Transonic Shock Solutions for One-Dimensional Euler-Poisson Equations
In this paper, both structural and dynamical stabilities of steady transonic
shock solutions for one-dimensional Euler-Poission system are investigated.
First, a steady transonic shock solution with supersonic backgroumd charge is
shown to be structurally stable with respect to small perturbations of the
background charge, provided that the electric field is positive at the shock
location. Second, any steady transonic shock solution with the supersonic
background charge is proved to be dynamically and exponentially stable with
respect to small perturbation of the initial data, provided the electric field
is not too negative at the shock location. The proof of the first stability
result relies on a monotonicity argument for the shock position and the
downstream density, and a stability analysis for subsonic and supersonic
solutions. The dynamical stability of the steady transonic shock for the
Euler-Poisson equations can be transformed to the global well-posedness of a
free boundary problem for a quasilinear second order equation with nonlinear
boundary conditions. The analysis for the associated linearized problem plays
an essential role
Kinetic Limit for Wave Propagation in a Random Medium
We study crystal dynamics in the harmonic approximation. The atomic masses
are weakly disordered, in the sense that their deviation from uniformity is of
order epsilon^(1/2). The dispersion relation is assumed to be a Morse function
and to suppress crossed recollisions. We then prove that in the limit epsilon
to 0 the disorder averaged Wigner function on the kinetic scale, time and space
of order epsilon^(-1), is governed by a linear Boltzmann equation.Comment: 71 pages, 3 figure
Crystal Structure, Infrared Spectra, and Microwave Dielectric Properties of Temperature-Stable Zircon-Type (Y,Bi)VO<inf>4</inf> Solid-Solution Ceramics
A series of (Bi 1-x Y x )VO 4 (0.4 ≤ x ≤ 1.0) ceramics were synthesized using the traditional solid-state reaction method. In the composition range of 0.4 ≤ x ≤ 1.0, a zircon-type solid solution was formed between 900 and 1550 °C. Combined with our previous work (scheelite monoclinic and zircon-type phases coexist in the range of x < 0.40), a pseudobinary phase diagram of BiVO 4 -YVO 4 is presented. As x decreased from 1.0 to 0.40, the microwave permittivity (ϵ r ) of (Bi 1-x Y x )VO 4 ceramics increased linearly from 11.03 to 30.9, coincident with an increase in the temperature coefficient of resonant frequency (TCF) from -61.3 to +103 ppm/°C. Excellent microwave dielectric properties were obtained for (Bi 0.3 Y 0.7 )VO 4 sintered at 1025 °C and (Bi 0.2 Y 0.8 )VO 4 sintered at 1075 °C with ϵ r ∼ 19.35, microwave quality factor (Qf) ∼ 25 760 GHz, and TCF ∼ +17.8 ppm/°C and ϵ r ∼ 16.3, Qf ∼ 31 100 GHz, and TCF ∼ -11.9 ppm/°C, respectively. Raman spectra, Shannon's additive rule, a classical oscillator model, and far-infrared spectra were employed to study the structure-property relations in detail. All evidence supported the premise that Bi-based vibrations dominate the dielectric permittivity in the microwave region
Quantum Probabilistic Subroutines and Problems in Number Theory
We present a quantum version of the classical probabilistic algorithms
la Rabin. The quantum algorithm is based on the essential use of
Grover's operator for the quantum search of a database and of Shor's Fourier
transform for extracting the periodicity of a function, and their combined use
in the counting algorithm originally introduced by Brassard et al. One of the
main features of our quantum probabilistic algorithm is its full unitarity and
reversibility, which would make its use possible as part of larger and more
complicated networks in quantum computers. As an example of this we describe
polynomial time algorithms for studying some important problems in number
theory, such as the test of the primality of an integer, the so called 'prime
number theorem' and Hardy and Littlewood's conjecture about the asymptotic
number of representations of an even integer as a sum of two primes.Comment: 9 pages, RevTex, revised version, accepted for publication on PRA:
improvement in use of memory space for quantum primality test algorithm
further clarified and typos in the notation correcte
Comparative proteomic analysis of aluminum tolerance in Tibetan wild and cultivated barleys
Aluminum (Al) toxicity is a major limiting factor for plant production in acid soils. Wild barley germplasm is rich in genetic diversity and may provide elite genes for crop Al tolerance improvement. The hydroponic-experiments were performed to compare proteomic and transcriptional characteristics of two contrasting Tibetan wild barley genotypes Al- resistant/tolerant XZ16 and Al-sensitive XZ61 as well as Al-resistant cv. Dayton. Results showed that XZ16 had less Al uptake and translocation than XZ61 and Dayton under Al stress. Thirty-five Al-tolerance/resistance-associated proteins were identified and categorized mainly in metabolism, energy, cell growth/division, protein biosynthesis, protein destination/storage, transporter, signal transduction, disease/defense, etc. Among them, 30 were mapped on barley genome, with 16 proteins being exclusively up-regulated by Al stress in XZ16, including 4 proteins (S-adenosylmethionine-synthase 3, ATP synthase beta subunit, triosephosphate isomerase, Bp2A) specifically expressed in XZ16 but not Dayton. The findings highlighted the significance of specific-proteins associated with Al tolerance, and verified Tibetan wild barley as a novel genetic resource for Al tolerance
Kinetics of coherent order-disorder transition in
Within a phase field approach which takes the strain-induced elasticity into
account, the kinetics of the coherent order-disorder transition is investigated
for the specific case of alloy. It is shown that a microstructure
with cubic precipitates appears as a transient state during the
decomposition of a homogeneous disordered solid solution into a microstructure
with tetragonal precipitates embedded into a disordered matrix. At
low enough temperature, favored by a weak internal stress, only
precipitates grow in the transient microstructure preceding nucleation of the
precipitates that occurs exclusively at the interface of the solid
solution with the precipitates. Analysis of microstructures at
nanoscopic scale shows a characteristic rod shape for the
precipitates due to the combination of their tetragonal symmetry and their
large internal stress.Comment: 2 postscript figures and 1 JPG pag
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