FRESH – FRI-based single-image super-resolution algorithm

In this paper, we consider the problem of single image super-resolution and propose a novel algorithm that outperforms state-of-the-art methods without the need of learning patches pairs from external data sets. We achieve this by modeling images and, more precisely, lines of images as piecewise smooth functions and propose a resolution enhancement method for this type of functions. The method makes use of the theory of sampling signals with finite rate of innovation (FRI) and combines it with traditional linear reconstruction methods. We combine the two reconstructions by leveraging from the multi-resolution analysis in wavelet theory and show how an FRI reconstruction and a linear reconstruction can be fused using filter banks. We then apply this method along vertical, horizontal, and diagonal directions in an image to obtain a single-image super-resolution algorithm. We also propose a further improvement of the method based on learning from the errors of our super-resolution result at lower resolution levels. Simulation results show that our method outperforms state-of-the-art algorithms under different blurring kernels

Hydrogen enhanced thermal fatigue of y-titanium aluminide

A study of hydrogen enhanced thermal fatigue cracking was carried out for a gamma-based Ti-48Al-2Cr alloy by cycling between room temperature and 750 or 900 °C. The results showed that hydrogen can severely attack the gamma alloy, with resulting lifetimes as low as three cycles, while no failures were observed in helium for test durations of over 4000 cycles. The severity of hydrogen attack strongly depends on the upper limit of the temperature cycled and the cleanliness of the hydrogen. Specifically, the large scatter of life times at 750 °C (ranging from 36 to more than 3000 cycles) have resulted from the competition between surface oxidation and hydrogen attack. The results suggest that an understanding of the combined actions of thermal cycling and hydrogen degradation is needed for assessing materials for high temperature applications in hydrogen

Is f1(1420)f_1(1420) the partner of f1(1285)f_1(1285) in the 3P1^3P_1 qqˉq\bar{q} nonet?

Based on a $2\times 2$ mass matrix, the mixing angle of the axial vector states $f_1(1420)$ and $f_1(1285)$ is determined to be $51.5^{\circ}$, and the theoretical results about the decay and production of the two states are presented. The theoretical results are in good agreement with the present experimental results, which suggests that $f_1(1420)$ can be assigned as the partner of $f_1(1285)$ in the $^3P_1$ $q\bar{q}$ nonet. We also suggest that the existence of $f_1(1510)$ needs further experimental confirmation.Comment: Latex, 6 pages, to be published in Chin. Phys. let

Quantum phase transitions of polar molecules in bilayer systems

We investigate the quantum phase transitions of bosonic polar molecules in a two-dimensional double layer system. We show that an interlayer bound state of dipoles (dimers) can be formed when the dipole strength is above a critical value, leading to a zero-energy resonance in the interlayer s-wave scattering channel. In the positive detuning side of the resonance, the strong repulsive interlayer pseudopotential can drive the system into a maximally entangled state, where the wave function is a superposition of two states that have all molecules in one layer and none in the other. We discuss how the zero-energy resonance, dimer states, and the maximally entangled state can be measured in time-of-flight experiments.Comment: Minor correction