Wafer-scale ultra-broadband perfect absorber based on ultrathin Al-SiO stack metasurfaces.

Broadband absorbers with high absorption, ultrathin thickness, and lithography-free planar structure have a wide range of potential applications, such as clocking and solar energy harvesting. For plasmonic metal materials, achieving perfect ultra-broadband absorption remains a challenge owing to the intrinsically narrow bandwidth. In this study, wafer-scale Al-SiO stack metasurfaces were experimentally fabricated to realize perfect ultra-broadband absorption.

Shot noise of spin-polarized electrons in a single-channel magnetic tunnel junctions.

Based on the free electron approximation and Egues' shot noise theory, the shot noise of spin-polarized electrons tunneling in ferromagnetic/semiconductor/ferromagnetic tunnel junctions is studied. Considering the matching of conduction band between ferromagnetic and semiconductor layers, our results show that the Fano factors of spin-polarized electrons have resonant tunneling characteristics when the semiconductor thickness and Rashba spin-orbit coupling strength are increased. When the magnetic moments in two ferromagnetic layers are parallel, with the increase of the molecular field in the ferromagnets, the Fano factor for spin-up electron decreases to zero and then increases exponentially and the Fano factor for spin-down electron is always linear.

[Ultrasound-guided percutaneous tube drainage combined with directly-viewed debridement with cholangioscopy: a mini-invasive strategy for peripancreatic necrotizing infection].

Objective: To establish "an integrative therapy" of drainage and debridement on peripancreatic necrotizing infection (PPNI) with minimally invasive technique, and to detect its clinical effects.

Methods: There were 17 patients who accepted ultrasound-guided percutaneous tube drainage combined with directly-viewed debridement with cholangioscopy from March 2006 to January 2008. Percutaneous puncture and catheter (6 - 8 F) drainage were adopted on the patients suffering from PPNI with B-us guidance, then the drainage sinus was expanded progressively from 8 F to 24 F in diameter with Cook fascia dilator by degrees, and the 22 F or 24 F tube was easily placed into the interior of PPNI instead of the prior catheter.