共查询到20条相似文献,搜索用时 62 毫秒
1.
M. A. Algatti R. P. Mota R. Y. Honda M. E. Kayama K. G. Kostov R. S. Fernandes T. C.A.M. Azevedo N. C. Cruz 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(2):325-328
This paper deals with plasma polymerization processes of diethylene glycol dimethyl ether. Plasmas were produced at 150 mtorr
in the range of 10 W to 40 W of RF power. Films were grown on silicon and quartz substrates. Molecular structure of plasma
polymerized films and their optical properties were analyzed by Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible
spectroscopy. The IR spectra show C–H stretching at 3000–2900 cm-1, C=O stretching at 1730–1650 cm-1, C–H bending at 1440–1380 cm-1, C–O and C–O–C stretching at 1200–1000 cm-1. The concentrations of C–H, C–O and C–O–C were investigated for different values of RF power. It can be seen that the C–H
concentration increases from 0.55 to 1.0 au (arbitrary unit) with the increase of RF power from 10 to 40 W. The concentration
of C–O and C–O–C decreases from 1.0 to 0.5 au in the same range of RF power. The refraction index increased from 1.47 to 1.61
with the increase of RF power. The optical gap calculated from absorption coefficient decreased from 5.15 to 3.35 eV with
the increase of power. Due to its optical and hydrophilic characteristics these films can be applied, for instance, as glass
lens coatings for ophthalmic applications. 相似文献
2.
A. Heidenreich I. Last J. Jortner 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(1):195-202
We present a theoretical and computational study of the properties and the
response of the nanoplasma and of outer ionization in Xen clusters (n =
55–2171, initial cluster radius R0 = 8.7–31.0 ?) driven by
ultraintense near-infrared laser fields (peak intensity IM = 1015–1020 Wcm-2, temporal pulse length τ= 10–100 fs, and frequency ν= 0.35 fs-1). The positively charged high-energy nanoplasma produced by inner ionization nearly follows the oscillations of
the fs laser pulse and can either be persistent (at lower intensities of IM = 1015–1016 Wcm-2 and/or for larger cluster sizes, where the electron energy distribution is nearly thermal) or transient (at higher intensities
of IM = 1018–1020 Wcm-2 and/or for smaller cluster sizes). The nanoplasma is depleted by outer ionization that was semiquantitatively described by
the cluster barrier suppression electrostatic model, which accounts for the cluster size, laser intensity and pulse length
dependence of the outer ionization yield. The electrostatic model was further utilized for estimates of the laser intensity
and pulse
width dependence of the border radius R0
(I) for the attainment of complete outer ionization at
,
while at R0 > R0
(I) a persistent nanoplasma prevails. R0
(I)
establishes an interrelationship between electron dynamics and nuclear Coulomb explosion dynamics in ultraintense
laser-cluster interactions. 相似文献
3.
Superheavy nuclei in deformed mean--field calculations 总被引:1,自引:0,他引:1
T. Bürvenich K. Rutz M. Bender P.–G. Reinhard J.A. Maruhn W. Greiner 《The European Physical Journal A - Hadrons and Nuclei》1998,3(2):139-147
The ground–state properties of superheavy nuclei are investigated within various parametrisations of relativistic and nonrelativistic
nuclear mean–field models. The heaviest known even–even nuclei starting with Z = 98 are used as a benchmark to estimate the
predictive power of the models and forces. From that starting point, deformed doubly magic nuclei are searched in the region
100 ≤ Z ≤ 130 and 142 ≤ N ≤ 190.
Received: 6 April 1998 / Revised version: 16 June 1998 相似文献
4.
C. P. Singh 《International Journal of Theoretical Physics》2006,45(3):519-528
Einstein field equations are considered in zero-curvature Robertson–Walker (R–W) cosmology with perfect fluid source and time-dependent gravitational and cosmological “constants.” Exact solutions of the field equations are obtained by using the ’gamma-law' equation of state p = (γ − 1)ρ in which γ varies continuously with cosmological time. The functional form of γ (R) is used to analyze a wide range of cosmological solutions at early universe for two phases in cosmic history: inflationary phase and Radiation-dominated phase. The corresponding physical interpretations of the cosmological solutions are also discussed. 相似文献
5.
T. Ritschel Ch. Zuhrt L. Zülicke P. J. Kuntz 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,41(1):127-141
ArnHCl+ van-der-Waals clusters for n = 1–13 are investigated
with the “minimal diatomics-in-molecules (DIM) model”
using ab-initio input data obtained from multi-reference
configuration-interaction calculations plus subsequent projection onto
valence-bond wavefunctions.
The results for the complexes with n = 1–3 are checked against
ab-initio calculations at the
coupled-cluster (CCSD) level with the same one-electron atomic basis set as
for the input data generation (aug-cc-pVTZ from Dunning).
In addition to the electronic ground state,
the first excited
state for the triatomic
complex (n = 1) is also studied.
The results
from the DIM model are shown to be in fair agreement with those from
advanced conventional ab-initio calculations, although there are
differences in detail. The comparison
justifies the extension of the DIM approach to n > 3.
Systematic analysis of the local minima of the multi-dimensional
potential-energy surfaces (PESs), carried out with the combined
method
described in part I (Monte-Carlo sampling plus subsequent steepest-descent
optimization), reveals simple building-up regularities for the most
stable structures (i.e. those corresponding to the global PES minimum)
at each n: apart from always having a nearly linear
(Ar–H–Cl)+ fragment as core, the aggregates show little
or no symmetry. Secondary local minima are also determined and their
structures interpreted.
The PESs for the low-lying excited states reveal a much more complicated
topography compared to the ArnH+ clusters allowing a variety
of photo-processes.
The energy level sequence of the first five excited electronic states
and the stability of the clusters in these states is studied
as a function of the cluster size n. 相似文献
6.
K. Yamasaki S. Juodkazis T. Lippert M. Watanabe S. Matsuo H. Misawa 《Applied Physics A: Materials Science & Processing》2003,76(3):325-329
We report the reversible micro-structuring of a synthetic rubber polymer (cis1,4-polybutadiene (PB)) by femtosecond laser
illumination. Visco-elastic relaxation of the optically damaged region was observed. The recovery time, typically 102–104 ms, can be varied by changing the irradiation pulse energy. Multi-shot-induced damage recovers on the much longer scale of
101–102 s. It was found that the doping of PB by 4 wt. % of pentazadiene ([4-NO2]–phenyl–N=N–N(C3H7)–N=N–phenyl–[4-NO2]) reduces the threshold of light-induced photo-modification by 20%. This is explained by photo-induced (homolytic) cleavage
of the pentazadiene bonds and formation of gaseous N2, which facilitates material failure at the irradiated spot.
The recovery of optical transmission can be applied to optical memory, optical and micro-mechanical applications. The underlying
mechanism of the phenomenon is discussed in terms of anelastic α- and β-relaxation (polymer backbone and chains/coils relaxation,
respectively).
Received: 11 October 2001 / Accepted: 9 July 2002 / Published online: 25 October 2002
RID="*"
ID="*"Corresponding author. Fax: +81-88/656-7598, E-mail: misawa@eco.tokushima-u.ac.jp 相似文献
7.
J. Kurpeta G. Lhersonneau J.C. Wang P. Dendooven A. Honkanen M. Huhta M. Oinonen H. Penttilä K. Peräjärvi J.R. Persson A. Płochocki J. Äystö 《The European Physical Journal A - Hadrons and Nuclei》1998,2(3):241-243
Very neutron–rich fission products of the mass chain A=113 obtained from the IGISOL on–line mass separator have been investigated
by γγ coincidence techniques and γ-spectra multiscaling. Gamma–rays following β–decay of 113Tc have been observed for the first time and a new 0.5 s isomeric state has been found in 113Ru.
Received: 10 February 1998 相似文献
8.
P. Armbruster 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,45(1):25-26
Complete fusion reactions (xn-channels) using actinide
targets are observed for values of the effective fissilities x eff ∼
0.80 in the sub-pb range of production cross sections. The elements
produced at this limit are Z = 108–112. Beyond complete fusion, heavier
elements might still be produced by reaction mechanisms releasing part of
the nuclear charge before an equilibrated compound system might have been
reached. Precompound Charged particle
Emission (PCE) is proposed as a possible mechanism following complete
fusion. A scheme delivering isotopes of elements Z = 110–115 is
discussed, and experimental evidence for such a process is presented.
Compound systems, the atomic numbers of which are smaller than in complete
fusion reactions, might be produced in 48Ca induced reactions on
actinides with larger cross sections than those at the limits of complete
fusion. Besides complete fusion, the PCE-mechanism should be considered as
an alternative to interpret the 48Ca-induced reactions on actinides. 相似文献
9.
B. Klipp M. Grass J. Müller D. Stolcic U. Lutz G. Ganteför T. Schlenker J. Boneberg P. Leiderer 《Applied Physics A: Materials Science & Processing》2001,73(5):547-554
A PACIS (pulsed arc cluster-ion source) developed for high average cluster-ion currents is presented. The performance of the
PACIS at different operational modes is described, and the suitability for cluster-deposition experiments is discussed in
comparison with other cluster-ion sources. Maximum currents of mass-selected cluster ions of 3–6 nA of small Sin
- (n=4–10) clusters and 0.3–0.5 nA of large Aln
+/- (n=20–70) clusters are achieved. The mass-selected cluster ions are soft-landed on a substrate at residual kinetic energies
lower than 1 eV/atom, and the samples are characterized by X-ray photoelectron spectroscopy and scanning tunneling microscopy.
First results on the soft landing of “magic” Si4
- clusters on graphite are presented.
Received: 30 May 2001 / Accepted: 14 June 2001 / Published online: 2 October 2001 相似文献
10.
A. Sacchetti T. Corridoni E. Arcangeletti P. Postorino 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,66(3):301-305
We report a high-pressure Raman study on two members of the La1-xCaxMnO3-δ manganite family (x = 0.20, δ = 0 and δ = 0.08). The results obtained for the δ = 0 sample show a different behavior in
the low and high pressure regime which is ascribed to the onset of a new pressure-activated interaction previously invoked
in other manganite compounds. The comparison of our results with literature data gives further support to the identification
of the Jahn-Teller sensitive stretching mode and shows that pressure-induced octahedral symmetrization is more effective in
systems exhibiting a lower metallic character. On the contrary the new interaction sets in at a pressure which decreases on
increasing the metallic character of the system indicating an important role of the Mn–Mn hopping integral in its activation. 相似文献
11.
J. Kurpeta A. Andreyev J. Äystö A.-H. Evensen M. Huhta M. Huyse A. Jokinen M. Karny E. Kugler J. Lettry A. Nieminen A. Płochocki M. Ramdhane H.L. Ravn K. Rykaczewski J. Szerypo P. Van Duppen G. Walter A. Wöhr 《The European Physical Journal A - Hadrons and Nuclei》2000,7(1):49-54
The decay of the neutron–rich isotope 216Bi, produced by proton–induced spallation at the PS Booster–ISOLDE facility, was investigated by β-γγ, αγ coincidence and
spectrum-multiscaling measurements. A new method for reducing isobaric contamination enabled to cover the unknown region “east”
of 208Pb for the isobaric chain A=216. The half-life of the β decay of 216Bi was found as T1/2= 135 ± 5 s. Its decay scheme was extended and the possible shell model configurations are proposed.
Received: 13 July 1999 / Revised version: 22 September 1999 相似文献
12.
V. Bernard N. Kaiser Ulf-G. Meißner 《The European Physical Journal A - Hadrons and Nuclei》1999,4(3):259-275
We evaluate the threshold matrix–element for the reaction pp→ppπ0 in a fully relativistic Feynman diagrammatic approach. We employ a simple effective range approximation to take care of the
S–wave pp final–state interaction. The experimental value for the threshold amplitude A = (2.7 −i0.3) fm4 can be reproduced by contributions from tree level chiral (long–range) pion exchange and short–range effects related to vector
meson exchanges, with ω-exchange giving the largest individual contribution. Pion loop effects appear to be small. We stress
that the commonly used heavy baryon formalism is not applicable in the NN–system above the pion production threshold due to
the large external momentum, |p|≃ (Mm
π)−1/2, with M and m
π the nucleon and the pion mass, respectively. We furthermore investigate the reaction pp→pnπ+ near threshold within the same approach. We extract from the data the triplet threshold amplitude as B = (2.8 −i1.5) fm4. Its real part can be well understood from (relativistic) tree level meson–exchange diagrams. In addition, we investigate
the process pp→ppη near threshold. We use a simple factorization ansatz for the ppη final–state interaction and extract from the data the modulus of the threshold amplitude, |C|= 1.32 fm4. With g
ηN= 5.3, this value can be reproduced by (relativistic) tree level meson–exchange diagrams and η–rescattering, whose strength
is fixed by the ηN scattering length. We also comment on the recent near threshold data for η′–production.
Received: 27 November 1998 相似文献
13.
M. Hinczewski A. N. Berker 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(4):461-472
The anisotropic d=3 tJ model is studied by
renormalization-group theory, yielding the evolution of the system
as interplane coupling is varied from the isotropic
three-dimensional to quasi-two-dimensional regimes.
Finite-temperature phase diagrams, chemical potential shifts, and
in-plane and interplane kinetic energies and antiferromagnetic
correlations are calculated for the entire range of electron
densities. We find that the novel τ phase, seen in earlier
studies of the isotropic d=3 tJ model, persists even for
strong anisotropy. While the τ phase appears at low
temperatures at 30–35% hole doping away from 〈
ni〉=1, at smaller hole dopings we see a complex lamellar
structure of antiferromagnetic and disordered regions, with a
suppressed chemical potential shift, a possible marker of
incommensurate ordering in the form of microscopic stripes. An
investigation of the renormalization-group flows for the isotropic
two-dimensional tJ model also shows a clear pre-signature of the
τ phase, which in fact appears with finite transition
temperatures upon addition of the smallest interplane coupling. 相似文献
14.
S. Verma J. J. Das A. Jhingan K. Kalita S. Barua K. S. Golda N. Madhavan P. Sugathan S. Nath T. Varughese J. Gehlot S. Mandal S. Ranjit P. K. Sahu B. John B. K. Nayak A. Saxena S. K. Datta R. Singh 《The European physical journal. Special topics》2007,150(1):75-78
Elastic scattering angular distributions have been measured for 7Be + 9Be system at Elab = 17, 19 and 21 MeV in the angular range θcm=26○–58°, and for 7Li + 9Be system at Elab= 15.75, 24 and 30 MeV.
An optical model (OM) analysis of these data have been carried out.
For the 7Li + 9Be system fusion cross sections were obtained at Elab = 15.75, 24 and 30 MeV by measuring the α-evaporation spectra from the compound nucleus at backward angles. The measured
α-evaporation spectra were reproduced by the statistical model calculations and fusion cross sections were extracted therefrom.
The ratios of the experimental fusion cross sections to the total reaction cross sections (obtained form OM analysis) were
found to be rather small. This result suggests that break-up process has a strong influence on fusion process leading to a
reduction in fusion cross section. 相似文献
15.
Alexander Horn Ilja Mingareev Alexander Werth Martin Kachel Udo Brenk 《Applied Physics A: Materials Science & Processing》2008,93(1):171-175
Using ultrafast laser radiation glass substrates are welded with glass and silicon plates. The pump beam is focused by a microscope
objective with large NA=0.4 (beam diameter 4 μm) into the glass. After partial absorption of the optical energy, the glass
is heated and melted. Procedures for high-quality welding of glass–glass and glass–silicon substrates with high-repetition
ultra-fast laser radiation have been derived at the repetition rate 700 kHz. The dependencies of the dimension and geometry
of the welding seam on scan velocity, repetition rate and pulse energy have been investigated defining a process window. Adding
a noninterferometric technique for quantitative phase detection with the welding setup, the interaction zone of the welding
seam for the welding partners glass–glass is detected. A change in refractive index is induced by heating and compression
of the glass and has been detected by phase detection up to 2 μs after irradiation with 100 fs time resolution. 相似文献
16.
G. Campi E. Cappelluti Th. Proffen X. Qiu E. S. Bozin S. J.L. Billinge S. Agrestini N. L. Saini A. Bianconi 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,52(1):15-21
We have studied temperature evolution of the local as well as the
average crystal structure of MgB2 using real-space atomic pair
distribution function (PDF) measured by high resolution neutron powder
diffraction in a wide temperature range of T=10–600 K. We find small
positive correlation factors for the B–B and B–Mg pairs, determined by
mean-square displacements (MSD) and the mean-square relative
displacements (MSRD). We analyze the PDF using both Einstein and
force constant models finding a good agreement between the
experimental data and the two models. This indicates that B and Mg
atomic correlations are not sensitive to the details of phonon
dispersion. 相似文献
17.
To gain more information about the highly excited rotational states of the Δv = 1 sequence of OD vibration-rotation bands, the spectrum has been produced in an inductively coupled plasma discharge and
measured with a Fourier transform spectrometer between 1670 and 5768 cm−1. Along with the extension of 1–0 band, we have been successful in recording the 2–1 band for the first time. A nonlinear
least square fit of these bands yielded equilibrium molecular parameters forv = 0, 1 and 2 levels with a standard deviation of 0·0032 cm−1. The centrifugal distortion parameters show a systematic vibrational dependence. 相似文献
18.
G.K. Kitaeva I.I. Naumova A.A. Mikhailovsky P.S. Losevsky A.N. Penin 《Applied physics. B, Lasers and optics》1998,66(2):201-205
3 crystals are measured in the transparency region (with the accuracy ±0.0002) and for the upper phonon polariton branch (with
the accuracy ±0.003–±0.05), from 0.44 μm up to 10.5 μm. The method of spontaneous parametric light scattering is used for
measurement of the ordinary refractive index dispersion in the mid-infrared region and for determination of the domain grating
period d=5.6±0.2 μm in the periodically-poled crystal.
Received: 29 January 1997/Revised version: 10 July 1997 相似文献
19.
Shigemasa Suga 《Applied Physics A: Materials Science & Processing》2008,92(3):479-485
InSe and InSe:Er single crystals were grown by using the Bridgman–Stockbarger method. The absorption measurements were carried
out for voltage U=0 and U=30 V states of InSe and InSe:Er samples in the temperature range of 10–320 K with a step of 10 K.
The absorption edge shifted towards longer wavelengths and the intensity of the absorption spectra decreased under a 5.90 kV/cm
electric field. The same binding energy values for InSe and InSe:Er were calculated as 22.2 and 14.2 meV at U=0 and U=30 V,
respectively. The steepness parameters and Urbach energies for InSe and InSe:Er samples increased with increasing sample temperature
in the range of 10–320 K. An applied electric field caused a shift and a decrease of the intensity of the absorption spectra
and an increase in the Urbach energy and steepness parameters. The shift of the absorption edge can be explained on the basis
of the Franz–Keldysh effect or thermal heating of the sample under the electric field.
PACS 71.20.Nr 相似文献
20.
Absolute frequency and isotope shift measurements of the cooling transition in singly ionized indium
Y. H. Wang R. Dumke J. Zhang T. Liu A. Stejskal Y. N. Zhao Z. H. Lu L. J. Wang Th. Becker H. Walther 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(2):307-311
We report greater than two orders of magnitude improvements in the absolute frequency and isotope shift measurements of the
In+ 5s2
1S0 (F = 9/2)–5s5p 3P1 (F = 11/2) transition near 230.6 nm. The laser-induced fluorescence from a single In+ in a radio-frequency trap is detected. The fourth-harmonic of a semiconductor laser is used as the light source. The absolute
frequency is measured with the help of a frequency comb referenced to a Cs atomic clock. The resulting transition frequencies
for isotopes 115In+ and 113In+ are measured to be 1 299 648 954.54(10) MHz and 1 299 649 585.36(16) MHz, respectively. The deduced cooling transition frequency
difference is 630.82(19) MHz. By taking into account of the hyperfine interaction, the isotope shift is calculated to be 695.76(1.68) MHz. 相似文献