123,042 research outputs found
Information Flow, Non-Markovianity and Geometric Phases
Geometric phases and information flows of a two-level system coupled to its
environment are calculated and analyzed. The information flow is defined as a
cumulant of changes in trace distance between two quantum states, which is
similar to the measure for non-Markovianity given by Breuer. We obtain an
analytic relation between the geometric phase and the information flow for pure
initial states, and a numerical result for mixed initial states. The geometric
phase behaves differently depending on whether there are information flows back
to the two-level system from its environment.Comment: 12 pages, 11 figure
Dynamics of ultra-intense circularly polarized solitons under inhomogeneous plasmas
The dynamics of the ultra-intense circularly polarized solitons under
inhomogeneous plasmas are examined. The interaction is modeled by the Maxwell
and relativistic hydrodynamic equations and is solved with fully implicit
energy-conserving numerical scheme. It is shown that a propagating weak soliton
can be decreased and reflected by increasing plasma background, which is
consistent with the existing studies based on hypothesis of weak density
response. However it is found that ultra-intense soliton is well trapped and
kept still when encountering increasing background. Probably, this founding can
be applied for trapping and amplifying high-intensity laser-fields.Comment: 4 pages, 3 figures, submitted to Phys. Plasma
Assessment of the NPP VIIRS RVS for the Thermal Emissive Bands Using the First Pitch Maneuver Observations
The Visible Infrared Imaging Radiometer Suite (VIIRS) is a key sensor carried on Suomi NPP (National Polar-orbiting Partnership) satellite (http://npp.gsfc.nasa.gov/viirs.html) (launched in October 2011). VIIRS sensor design draws on heritage instruments including AVHRR, OLS, SeaWiFS and MODIS. It has on-board calibration components including a solar diffuser (SD) and a solar diffuser stability monitor (SDSM) for the reflective solar bands (RSB), a V-groove blackbody for the thermal emissive bands (TEB), and a space view (SV) port for background subtraction. These on-board calibrators are located at fixed scan angles. The VIIRS response versus scan angle (RVS) was characterized prelaunch in lab ambient conditions and is currently used to characterize the on-orbit response for all scan angles relative to the calibrator scan angle (SD for RSB and blackbody for TEB). Since the RVS is vitally important to the quality of calibrated radiance products, several independent studies were performed to analyze the prelaunch RVS measurement data. A spacecraft level pitch maneuver was scheduled during the first three months of intensive Cal/Val. The NPP pitch maneuver provided a rare opportunity for VIIRS to make observations of deep space over the entire range of scan angles, which can be used to characterize the TEB RVS. This study will provide our analysis of the pitch maneuver data and assessment of the derived TEB RVS. A comparison between the RVS determined by the pitch maneuver observations and prelaunch lab tests will be conducted for each band, detector, and half angle mirror (HAM) sid
Recommended from our members
Bioinspired Multifunctional Anti-icing Hydrogel
The recent anti-icing strategies in the state of the art mainly focused on three aspects: inhibiting ice nucleation, preventing ice propagation, and decreasing ice adhesion strength. However, it is has proved difficult to prevent ice nucleation and propagation while decreasing adhesion simultaneously, due to their highly distinct, even contradictory design principles. In nature, anti-freeze proteins (AFPs) offer a prime example of multifunctional integrated anti-icing materials that excel in all three key aspects of the anti-icing process simultaneously by tuning the structures and dynamics of interfacial water. Here, inspired by biological AFPs, we successfully created a multifunctional anti-icing material based on polydimethylsiloxane-grafted polyelectrolyte hydrogel that can tackle all three aspects of the anti-icing process simultaneously. The simplicity, mechanical durability, and versatility of these smooth hydrogel surfaces make it a promising option for a wide range of anti-icing applications
- …
