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111.
J. Dabrowski J. Rożynek G.S. Anagnostatos 《The European Physical Journal A - Hadrons and Nuclei》2002,14(1):125-131
It is shown that among four models of the Nijmegen baryon-baryon interaction only model F --which leads to a repulsive potential
felt by the Σ hyperon inside the nucleus-- is consistent both with the analysis of Σ- atoms and of the (K
-,π) reactions. The Nijmegen models are used to determine the strong complex single-particle (s.p.) potential of Σ-, and to calculate the strong-interaction shifts and widths of the lowest observed levels of Σ- atoms. The results obtained with model F are in best agreement with the experimental data.
Received: 15 January 2002 / Accepted: 14 March 2002 相似文献
112.
J. Kurpeta G. Lhersonneau A. Płochocki J.C. Wang P. Dendooven A. Honkanen M. Huhta M. Oinonen H. Penttilä K. Peräjärvi J.R. Persson J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》2002,13(4):449-460
The decay of neutron-rich isotope 113Ru obtained as on-line mass separated product of proton-induced fission has been investigated by γγ coincidence and spectrum
multiscaling measurements. Decay schemes for both low- and high-spin isomers of 113Ru have been constructed. The level scheme of 113Rh is considerably extended. Systematics of the lowest-lying rhodium levels is smooth. The picture of shape coexistence established
for neutron-rich Rh isotopes near-neutron midshell is confirmed with the observation of a K = 1/2 deformed band, with its 3/2+ state at 600 keV being the lowest-lying level and of probable 7/2+
and 5/2+
band members. A large fraction of β feeding is found to populate high-lying levels in 113Rh. The GT strength in 113Rum decay is significantly larger than for the decay of 113Rug and of lighter rhodium isotopes.
Received: 18 January 2001 / Accepted: 14 January 2002 相似文献
113.
Hexagonal-pillar shaped pure Fe single crystal whiskers with six {1 1 0} side planes were obtained by means of chemical vapor deposition. Atomically resolved scanning tunneling microscopy images obtained on the {1 1 0} surface showed a quasi-hexagonal atomic array with mesoscopic-range periodic height modulation of about 1/3 of an atomic step. This height modulation was found to be a result of an interference between the quasi-hexagonal top-layer and the sub-surface bcc-Fe{1 1 0} layer. Unit vectors of the mesoscopic-range modulation turned out to be expressed as , where and are the primitive vectors of the two-dimensional atomic array in the top-layer and those in the sub-surface layer, respectively. The two-dimensional density of atoms in the top-layer is slightly higher by 0.46% than that in the sub-surface layer. 相似文献
114.
We investigated the subpicosecond laser ablation of copper and fused silica under 100 fs laser irradiation at 800 nm in vacuum by means of fast plume imaging and time- and space-resolved optical emission spectroscopy. We found that, to the difference of copper ablation, the laser-generated plasma from a fused silica target exhibited one “main” component only. The “slow” plasma component, observed during copper ablation and usually assigned to optical emission from nanoparticles was not detected by either plasma fast imaging or optical emission spectroscopy even when fused silica targets were submitted to the highest incident fluences used in our experiments. The characteristic expansion velocity of this unique component was about three times larger than the velocity of the fast plume component observed during copper ablation. The dependence of laser fluence on both plasma expansion and ablation rate was investigated and discussed in terms of ablation efficiency and initiation mechanisms. 相似文献
115.
R. Vladoiu M. Contulov A. Mandes G. Musa 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(2):287-291
The M-effect (monochromatization-effect) is a powerful tool which can give high intensity monochromatic spectra with a certain
wavelength depending on the type of used gas mixtures to generate plasma state. The effect consists in the emission of a single
spectral line of plasmas ignited in certain gas mixtures. The main condition to obtain the M effect is the presence of an
electropositive and an electronegative gas mixture. For example, in the case of Ne+H2 monochrome radiation was obtained, the wavelength of Ne being 585.3 nm (1s2–2p5). In this paper we prove the general character of this effect, i.e. if the optical emission spectra reduced to nearly one
line can be observed also in other gas mixture discharges, for example in the case of one electronegative gas and two electropositive
gases. Different other mixtures, as Xe+Ne+H2 and Xe+Ar+H2 have been studied. In all these cases, the M-effect appeared without doubt. 相似文献
116.
H. Nowakowska M. Jasiński J. Mizeraczyk 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(2):511-518
We present results from simulations of 2D distributions of the electromagnetic field inside a waveguide-based axial-type microwave
plasma source (MPS) used for hydrogen production via methane reforming. The studies are aimed at optimization of discharge
processes and hydrogen production. We derive equations for determining electromagnetic field distributions and next determine
the electromagnetic field distributions for two cases – without and with plasma inside the MPS. For the first case, we examine
the influence of the length of the inner conductor of the coaxial line on electromagnetic field distributions. We have obtained
standing wave patterns along the coaxial line and found resonances for certain positions of the coaxial line inner conductor.
For the case with plasma inside the MPS, we perform calculations assuming that distributions of plasma parameters are known.
Simulations are done for several values of maximum electron density. We have found that for values of electron density greater
than strong skin effect in the plasma is observed. Consequently, plasma may be treated as an extension of the inner conductor
of the coaxial line. We have used FlexPDE software for the calculations. 相似文献
117.
D. Helbing 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(4):569-570
This contribution compares several different approaches allowing one to derive macroscopic traffic equation directly from
microscopic car-following models. While it is shown that some conventional approaches lead to theoretical problems, it is
proposed to use an approach reminding of smoothed particle hydrodynamics to avoid gradient expansions. The derivation circumvents
approximations and, therefore, demonstrates the large range of validity of macroscopic traffic equations, without the need
of averaging over many vehicles. It also gives an expression for the “traffic pressure”, which generalizes previously used
formulas. Furthermore, the method avoids theoretical inconsistencies of macroscopic traffic models, which have been criticized
in the past by Daganzo and others. 相似文献
118.
Y. Huang L. Wu S. Q. Zhu 《The European Physical Journal B - Condensed Matter and Complex Systems》2009,69(3):431-438
The interaction between the evolution of the game and the underlying network structure with evolving snowdrift game model
is investigated. The constructed network follows a power-law degree distribution typically showing scale-free feature. The
topological features of average path length, clustering coefficient, degree-degree correlations and the dynamical feature
of synchronizability are studied. The synchronizability of the constructed networks changes by the interaction. It will converge
to a certain value when sufficient new nodes are added. It is found
that initial payoffs of nodes greatly affect the synchronizability. When initial payoffs for players are equal, low common
initial payoffs may lead to more heterogeneity of the network and good
synchronizability. When initial payoffs follow certain distributions, better synchronizability is obtained compared to equal
initial payoff. The result is also true for phase synchronization of nonidentical oscillators. 相似文献
119.
Han Wang Christoph Junghans Kurt Kremer 《The European physical journal. E, Soft matter》2009,28(2):221-229
We employ the inverse Boltzmann method to coarse-grain three commonly used three-site water models (TIP3P, SPC and SPC/E)
where one molecule is replaced with one coarse-grained particle with isotropic two-body interactions only. The shape of the
coarse-grained potentials is dominated by the ratio of two lengths, which can be rationalized by the geometric constraints
of the water clusters. It is shown that for simple two-body potentials either the radial distribution function or the geometrical
packing can be optimized. In a similar way, as needed for multiscale methods, either the pressure or the compressibility can
be fitted to the all atom liquid. In total, a speed-up by a factor of about 50 in computational time can be reached by this
coarse-graining procedure. 相似文献
120.
F. X. Bronold H. Deutsch H. Fehske 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(3):519-544
Plasma-boundaries floating in an ionized gas are usually negatively charged. They accumulate electrons more efficiently than
ions leading to the formation of a quasi-stationary electron film at the boundaries. We propose to interpret the build-up
of surface charges at inert plasma boundaries, where other surface modifications, for instance, implantation of particles
and reconstruction or destruction of the surface due to impact of high energy particles can be neglected, as a physisorption
process in front of the wall. The electron sticking coefficient se and the electron desorption time τe, which play an important role in determining the quasi-stationary surface charge, and about which little is empirically and
theoretically known, can then be calculated from microscopic models for the electron-wall interaction. Irrespective of the
sophistication of the models, the static part of the electron-wall interaction determines the binding energy of the electron,
whereas inelastic processes at the wall determine se and τe. As an illustration, we calculate se and τe for a metal, using the simplest model in which the static part of the electron-metal interaction is approximated by the classical
image potential. Assuming electrons from the plasma to loose (gain) energy at the surface by creating (annihilating) electron-hole
pairs in the metal, which is treated as a jellium half-space with an infinitely high workfunction, we obtain se≈10-4 and τe≈10-2 s. The product seτe≈10-6 s has the order of magnitude expected from our earlier results for the charge of dust particles in a plasma but individually se is unexpectedly small and τe is somewhat large. The former is a consequence of the small matrix elements occurring in the simple model while the latter
is due to the large binding energy of the electron. More sophisticated theoretical investigations, but also experimental support,
are clearly needed because if se is indeed as small as our exploratory calculation suggests, it would have severe consequences for the understanding of the
formation of surface charges at plasma boundaries. To identify what we believe are key issues of the electronic microphysics
at inert plasma boundaries and to inspire other groups to join us on our journey is the purpose of this colloquial presentation. 相似文献