Two-scale structure of the electron dissipation region during collisionless magnetic reconnection

Particle-in-cell simulations of collisionless magnetic reconnection are presented that demonstrate that reconnection remains fast in very large systems. The electron dissipation region develops a distinct two-scale structure along the outflow direction. Consistent with fast reconnection, the length of the electron current layer stabilizes and decreases with decreasing electron mass, approaching the ion inertial length for a proton-electron plasma. Surprisingly, the electrons form a super-Alfvénic outflow jet that remains decoupled from the magnetic field and extends large distances downstream from the x line.     

Unpredicted electron injection in CdS/CdSe quantum dot sensitized ZrO2 solar cells

A quantum dot sensitized solar cell based on a porous ZrO(2) film, sensitized with CdSe quantum dots using CdS as an intermediate layer is presented. We observe electron injection from photo-excited quantum dots into the ZrO(2), which is unexpected due to the much higher conduction band edge (closer to the vacuum level) of bulk ZrO(2) compared to TiO(2).     

Engineering of SiO2-Au-SiO2 sandwich nanoaggregates using a building block: single, double, and triple cores for enhancement of near infrared fluorescence

We have developed a simple and flexible chemical method to synthesize orderly metallic nanoaggregates using a designed SiO 2-Au core-shell building block. The number of the building blocks in a nanoaggregate is tunable from one to three. These metal nanostructures can generate an enlarged localized electromagnetic field through surface plasmon resonance and enhance the optical signals of the photoactive molecules within this electromagnetic field. Aggregates of metallic nanoparticles provide a higher signal enhancement than well-dispersed nanoparticles combined. The level of signal enhancement is determined by the number of building blocks in a nanoaggregate. The signal enhancement of the nanoaggregates has been verified with a near-infrared (NIR) dye. In the NIR region, biological samples have low background signals and deeper penetration of radiation. The application of these NIR enhanced metal nanostructures will open a significant approach for sensitive detection of biological samples.