12,246 research outputs found
Method of improving contact bonds in silicon integrated circuits
Fabrication method produces stable and reliable metallic systems for interconnections, contact pads, and bonded leads in silicon planar integrated circuits. The method is based on substrate isolation of the interconnection metal from the contact pad and bonded wire
XPS characterization of silver electrodes and catalyst for oxygen reduction
The combined analysis of the silver GDE using an ex-situ surface sensitive technique (XPS) and in-situ electrochemical measurements (EIS, CV) show that the performance of the silver GDE is significantly influenced by the degree of degradation of the electrodes, e. g., the reduction of the active surface due to the decomposition of the PTFE. These findings indicate a different degree of decomposition of the PTFE on the on the GDE
Incommensurate dynamics of resonant breathers in Josephson junction ladders
We present theoretical and experimental studies of resonant localized
resistive states in a Josephson junction ladder. These complex breather states
are obtained by tuning the breather frequency into the upper band of linear
electromagnetic oscillations of the ladder. Their prominent feature is the
appearance of resonant steps in the current-voltage (I-V) characteristics. We
have found the resonant breather-like states displaying incommensurate
dynamics. Numerical simulations show that these incommensurate resonant
breathers persist for very low values of damping. Qualitatively similar
incommensurate breather states are observed in experiments performed with
Nb-based Josephson ladders. We explain the appearance of these states with the
help of resonance-induced hysteresis features in the I-V dependence.Comment: 5 pages, 6 figure
Parallels between the dynamics at the noise-perturbed onset of chaos in logistic maps and the dynamics of glass formation
We develop the characterization of the dynamics at the noise-perturbed edge
of chaos in logistic maps in terms of the quantities normally used to describe
glassy properties in structural glass formers. Following the recognition [Phys.
Lett. \textbf{A 328}, 467 (2004)] that the dynamics at this critical attractor
exhibits analogies with that observed in thermal systems close to
vitrification, we determine the modifications that take place with decreasing
noise amplitude in ensemble and time averaged correlations and in diffusivity.
We corroborate explicitly the occurrence of two-step relaxation, aging with its
characteristic scaling property, and subdiffusion and arrest for this system.
We also discuss features that appear to be specific of the map.Comment: Revised version with substantial improvements. Revtex, 8 pages, 11
figure
Magnetic, electronic and vibrational properties of metal and fluorinated metal phthalocyanines
The magnetic and electronic properties of metal phthalocyanines (MPc) and
fluorinated metal phthalocyanines (FMPc) are studied by means of spin
density functional theory (SDFT). Several metals (M) such as Ca, all first
d-row transition metals and Ag are investigated. By considering different open
shell transition metals it is possible to tune the electronic properties of
MPc, in particular the electronic molecular gap and total magnetic moment.
Besides assigning the structural and electronic properties of MPc and
FMPc, the vibrational modes analysis of the ScPc\textendash ZnPc series
have been studied and correlated to experimental measurements when available.Comment: 28 pages (preprint style), several figure
Sierpinski signal generates spectra
We investigate the row sum of the binary pattern generated by the Sierpinski
automaton: Interpreted as a time series we calculate the power spectrum of this
Sierpinski signal analytically and obtain a unique rugged fine structure with
underlying power law decay with an exponent of approximately 1.15. Despite the
simplicity of the model, it can serve as a model for spectra in a
certain class of experimental and natural systems like catalytic reactions and
mollusc patterns.Comment: 4 pages (4 figs included). Accepted for publication in Physical
Review
Deep learning based pulse shape discrimination for germanium detectors
Experiments searching for rare processes like neutrinoless double beta decay
heavily rely on the identification of background events to reduce their
background level and increase their sensitivity. We present a novel machine
learning based method to recognize one of the most abundant classes of
background events in these experiments. By combining a neural network for
feature extraction with a smaller classification network, our method can be
trained with only a small number of labeled events. To validate our method, we
use signals from a broad-energy germanium detector irradiated with a Th
gamma source. We find that it matches the performance of state-of-the-art
algorithms commonly used for this detector type. However, it requires less
tuning and calibration and shows potential to identify certain types of
background events missed by other methods.Comment: Published in Eur. Phys. J. C. 9 pages, 10 figures, 3 table
Parametric Feedback Resonance in Chaotic Systems
If one changes the control parameter of a chaotic system proportionally to the distance between an arbitrary point on the strange attractor and the actual trajectory, the lifetime Ď„ of the most stable unstable periodic orbit in the vicinity of this point starts to diverge with a power law. The volume in parameter space where Ď„ becomes infinite is finite and from its nonfractal boundaries one can determine directly the local Liapunov exponents. The experimental applicability of the method is demonstrated for two coupled diode resonators
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