153 research outputs found
Automated assessment of redox potentials for dyes in dye-sensitized photoelectrochemical cells
NWO733.000.007Solid state NMR/Biophysical Organic Chemistr
Amorphous carbon film deposition on inner surface of tubes using atmospheric pressure pulsed filamentary plasma source
Uniform amorphous carbon film is deposited on the inner surface of quartz
tube having the inner diameter of 6 mm and the outer diameter of 8 mm. A pulsed
filamentary plasma source is used for the deposition. Long plasma filaments (~
140 mm) as a positive discharge are generated inside the tube in argon with
methane admixture. FTIR-ATR, XRD, SEM, LSM and XPS analyses give the conclusion
that deposited film is amorphous composed of non-hydrogenated sp2 carbon and
hydrogenated sp3 carbon. Plasma is characterized using optical emission
spectroscopy, voltage-current measurement, microphotography and numerical
simulation. On the basis of observed plasma parameters, the kinetics of the
film deposition process is discussed
Final state effects on superfluid He in the deep inelastic regime
A study of Final State Effects (FSE) on the dynamic structure function of
superfluid He in the Gersch--Rodriguez formalism is presented. The main
ingredients needed in the calculation are the momentum distribution and the
semidiagonal two--body density matrix. The influence of these ground state
quantities on the FSE is analyzed. A variational form of is used, even
though simpler forms turn out to give accurate results if properly chosen.
Comparison to the experimental response at high momentum transfer is performed.
The predicted response is quite sensitive to slight variations on the value of
the condensate fraction, the best agreement with experiment being obtained with
. Sum rules of the FSE broadening function are also derived and
commented. Finally, it is shown that Gersch--Rodriguez theory produces results
as accurate as those coming from other more recent FSE theories.Comment: 20 pages, RevTex 3.0, 11 figures available upon request, to be appear
in Phys. Rev.
Multiple scattering approach to low-energy electron collisions with the water dimer
Multiple scattering theory is applied to low-energy electron collisions with
a complex target formed of two molecular scatterers. The total T-matrix is
expressed in terms of the T-matrix for each isolated molecule. We apply the
approach to elastic electron-(H2O)2 collisions. Following the method developed
in our previous work on crystalline ice, we impose a cut-off on the dipole
outside the R-matrix sphere and an energy dependent cut-off on the angular
momentum components of the monomer T-matrix. An R-matrix calculation of
electron-dimer collisions is performed in order to evaluate the accuracy of the
multiple scattering approach. The agreement between the two calculations is
very good.Comment: 15 pages, 4 figures New submission: Added references Included PACS
numbers Figure 3 slightly changed Additions made to the Conclusions and
Discussion sectio
Strong fragmentation of low-energy electromagnetic excitation strength in Sn
Results of nuclear resonance fluorescence experiments on Sn are
reported. More than 50 transitions with MeV were
detected indicating a strong fragmentation of the electromagnetic excitation
strength. For the first time microscopic calculations making use of a complete
configuration space for low-lying states are performed in heavy odd-mass
spherical nuclei. The theoretical predictions are in good agreement with the
data. It is concluded that although the E1 transitions are the strongest ones
also M1 and E2 decays contribute substantially to the observed spectra. In
contrast to the neighboring even Sn, in Sn the
component of the two-phonon quintuplet built on top of
the 1/2 ground state is proved to be strongly fragmented.Comment: 4 pages, 3 figure
Search for the electric dipole excitations to the multiplet in Sn
The odd-mass Sn nucleus was investigated in nuclear resonance
fluorescence experiments up to an endpoint energy of the incident photon
spectrum of 4.1 MeV at the bremsstrahlung facility of the Stuttgart University.
More than 50 mainly hitherto unknown levels were found. From the measurement of
the scattering cross sections model independent absolute electric dipole
excitation strengths were extracted. The measured angular distributions
suggested the spins of 11 excited levels. Quasi-particle phonon model
calculations including a complete configuration space were performed for the
first time for a heavy odd-mass spherical nucleus. These calculations give a
clear insight in the fragmentation and distribution of the , , and
excitation strength in the low energy region. It is proven that the
component of the two-phonon quintuplet built on
top of the ground state is strongly fragmented. The theoretical
calculations are consistent with the experimental data.Comment: 10 pages, 5 figure
Transition Rates between Mixed Symmetry States: First Measurement in 94Mo
The nucleus 94Mo was investigated using a powerful combination of
gamma-singles photon scattering experiments and gamma-gamma-coincidence studies
following the beta-decay of 94mTc. The data survey short-lived J^pi=1+,2+
states and include branching ratios, E2/M1 mixing ratios, lifetimes, and
transition strengths. The mixed-symmetry (MS) 1+ scissors mode and the 2+ MS
state are identified from M1 strengths. A gamma transition between MS states
was observed and its rate was measured. Nine M1 and E2 strengths involving MS
states agree with the O(6) limit of the interacting boson model-2 using the
proton boson E2 charge as the only free parameter.Comment: 9 pages, 3 PostScript figures included, ReVTeX, accepted for
publication in Physical Review Letters, tentatively scheduled for August 9,
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