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991.
T. Schenkel A.V. Barnes A.V. Hamza D.H. Schneider 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,1(3):297-302
Cluster ion emission from a variety of surfaces upon impact of highly charged ions is investigated by time-of-flight secondary
ion mass spectrometry. The yield of cluster ions as a function of cluster size for and surface follow a power law decline with exponent approaching the -2 limit of the ”equilibrium” and ”shock wave” cluster emission
models. While the decline of the cluster ion emission with cluster size is an exponential decay for highly oriented pyrolytic
graphite upon impact, the decline is more gradual than for impact, such that at the relative cluster yield is 1000 times higher.
Received: 22 April 1997 / Revised: 29 December 1997 / Accepted: 19 January 1998 相似文献
992.
Y. Tai J. Murakami K. Saito M. Ikeyama K. Tajiri M. Watanabe S. Tanemura T. Mizota 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):261-263
Plasma desorption mass spectrometry has been applied to
characterization of dodecanthiol-passivated gold nanoparticles.
An overview of the experimental set-up and mass analyses for the
nanoparticles prepared in different conditions are shown. Mass
distributions were found to shift to higher mass regions with
increasing reaction temperature and reaction period. The results
are consistent with those of transmission electron microscopy
observations, UV-visible absorption spectra and also with a
reported laser desorption mass spectrometry. 相似文献
993.
60 polymerization in the temperature interval at pressures below by measurements of the time dependence of the thermal conductivity. It has been found at that the polymerization process at is slower than the reverse transformation from “polymeric” to “monomeric” phase at . The thermal conductivity of polymerized C60 was measured in the temperature range and found to increase with increasing temperature, which reflects strong phonon scattering. Both the presence of non-bonded
C60 molecules and a high degree of structural disorder in the crystalline lattice of the polymeric phase might be responsible
for the behaviour of . The results for are qualitatively similar to those reported previously for C60 polymerized at higher , but an order of magnitude smaller.
Received: 20 September 1996/Accepted: 11 November 1996 相似文献
994.
K. Van de Vel A.N. Andreyev R.D. Page H. Kettunen P.T. Greenlees P. Jones R. Julin S. Juutinen H. Kankaanpää A. Keenan P. Kuusiniemi M. Leino M. Muikku P. Nieminen P. Rahkila J. Uusitalo K. Eskola A. Hürstel M. Huyse Y. Le Coz M.B. Smith P. Van Duppen R. Wyss 《The European Physical Journal A - Hadrons and Nuclei》2003,17(2):167-171
Gamma rays from excited states of 190Po have been observed using the Jurosphere Ge-detector array coupled to the RITU gas-filled separator. They were associated
with a collective band which from spin 4 onwards resembles the prolate rotational bands known in the isotones 188Pb and 186Hg. This indicates that in 190Po the prolate configuration becomes yrast above I = 2. The experimental results are interpreted in a two-band mixing calculation and are in agreement with α-decay data and
potential energy surface calculations.
Received: 10 January 2003 / Accepted: 19 February 2003 / Published online: 7 May 2003 相似文献
995.
A magnetic fringe-field effect has been investigated for a simple bilayer device structure consisting of a Co0.9Fe0.1 film and an epitaxial YBa2Cu3O7−δ (YBCO) film patterned as a microbridge. The resistance of the bridge is measured with a four-probe technique and is found to depend on the orientation of a magnetic field, which is externally applied in the device plane. A maximum (minimum) of the resistance occurs when the magnetic field is applied in parallel (perpendicular) to the bridge axis. The difference between the maximum and the minimum is very large for a small range of temperature below the critical temperature of the YBCO film. The observed features in the resistance are qualitatively explained by vortex motion in the YBCO bridge under the influence of the magnetic fringe-field of the Co0.9Fe0.1 film. 相似文献
996.
We analyse the optimized geometric structure and energies of N,N′-diphenyl-N,N′-bis(3-methylphenyl)-(1,1′-biphenyl)-4,4′-diamine (TPD) neutral molecule in ground and excited states. Ab initio calculations are performed at the Hartree–Fock (HF) or single-excitation (CIS) level with 6-31G basis set using Gaussian 98 program. We got a good qualitative agreement with the results for the neutral molecule in the ground state obtained by density functional theory methods, which were previously reported in the literature. TPD in the ground state has a pronounced twisted geometry, with both central and peripheral dihedral angles of about 40°. On the other hand, the structure of excited state is more planar, as the central dihedral angle becomes smaller. We estimated the reorganization energies associated with the optical transitions, corresponding transition dipole moments, as well as HOMO and LUMO. On the basis of ab initio calculations, we developed a semi-empirical model for the observed absorption and photoluminescence and interpreted the large Stokes shift of about 0.4 eV. 相似文献
997.
E. Träbert S. Fritzsche C. Jupén 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1998,3(1):13-20
Delayed spectra of foil-excited fast Cu ions have been studied to find a number of 3s3p4, 3
s2
3
p2
3
d and 3s3p33d levels in the P-like ion Cu14+ (spectrum Cu XV). Among these are 3
s
3
p3
3
d
6
D levels, which have never been observed before, although they are the lowest excited states that have the same parity as the
ground configuration. The investigation combined theory and experiment. The calculations used the Cowan code with semi-empirically
scaled parameters and extensive MCDF computations.
Received: 14 April 1998 / Accepted: 18 April 1998 相似文献
998.
Vjekoslav Sajfert Nikola Bucalović Ljiljana Mašković Bratislav Tošić 《Czechoslovak Journal of Physics》2006,56(3):253-265
The method of evaluation of broken-symmetry Green’s function is presented. This method was applied to electron subsystem of
a thin film. It was found that electron concentrations are spatially dependent and their spatial distribution proves the existence
of skin effect. The skin effect is most expressed in the films of minimal thickness. The internal energy of electrons lying
in the film Fermi volume, decreases with the increase of temperature. It is the consequence of the Pauli principle, which
does not allow change of electron velocities. Introduced heat increases electron effective masses and this leads to the decrease
of internal energy. 相似文献
999.
Metallic zinc one-dimensional materials including nanotubes and nanowires were synthesized on a large scale by a simple method. The process was both catalyst and template free. The resulting Zn nanotubes and Zn nanowires were characterized and confirmed by means of X-ray diffraction, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and transmission electron microscopy. The growth of Zn nanotubes was reported for the first time. 相似文献
1000.
Nanoscience and nanotechnology represent scientific‐technical areas that in less than twenty years have gone from being in the hands of a small group of researchers who glimpsed their great potential, to constitute one of the recognized pillars of scientific progress for the next decades. This paper illustrates how the irruption of the nanotechnologies will directly affect human beings by substantially improving diagnosis and treatment of diseases as well as our capacities to interact with our surroundings. Governments around the world have realized the important role that nanotechnology deserves, and during the last decade budgets allocated to research and development in nanotechnology have continuously increased. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献