712 research outputs found
Violation of Leggett-Garg inequalities in quantum measurements with variable resolution and back-action
Quantum mechanics violates Leggett-Garg inequalities because the operator
formalism predicts correlations between different spin components that would
correspond to negative joint probabilities for the outcomes of joint
measurements. However, the uncertainty principle ensures that such joint
measurements cannot be implemented without errors. In a sequential measurement
of the spin components, the resolution and back-action errors of the
intermediate measurement can be described by random spin flips acting on an
intrinsic joint probability. If the error rates are known, the intrinsic joint
probability can be reconstructed from the noisy statistics of the actual
measurement outcomes. In this paper, we use the spin-flip model of measurement
errors to analyze experimental data on photon polarization obtained with an
interferometric setup that allows us to vary the measurement strength and hence
the balance between resolution and back-action errors. We confirm that the
intrinsic joint probability obtained from the experimental data is independent
of measurement strength and show that the same violation of the Leggett-Garg
inequality can be obtained for any combination of measurement resolution and
back-action.Comment: 17 pages, 7 figure
Seasonal variation of aliphatic amines in marine sub-micrometer particles at the Cape Verde islands
Monomethylamine (MA), dimethylamine (DMA) and diethylamine (DEA) were detected at non-negligible concentrations in sub-micrometer particles at the Cap Verde Atmospheric Observatory (CVAO) located on the island of São Vicente in Cape Verde during algal blooms in 2007. The concentrations of these amines in five stage impactor samples ranged from 0–30 pg m−3 for MA, 130–360 pg m−3 for DMA and 5–110 pg m−3 for DEA during the spring bloom in May 2007 and 2–520 pg m−3 for MA, 100–1400 pg m−3 for DMA and 90–760 pg m−3 for DEA during an unexpected winter algal bloom in December 2007. Anomalously high Saharan dust deposition and intensive ocean layer deepening were found at the Atmospheric Observatory and the associated Ocean Observatory during algal bloom periods. The highest amine concentrations in fine particles (impactor stage 2, 0.14–0.42 μm) indicate that amines are likely taken up from the gas phase into the acidic sub-micrometer particles. The contribution of amines to the organic carbon (OC) content ranged from 0.2–2.5% C in the winter months, indicating the importance of this class of compounds to the carbon cycle in the marine environment. Furthermore, aliphatic amines originating from marine biological sources likely contribute significantly to the nitrogen content in the marine atmosphere. The average contribution of the amines to the detected nitrogen species in sub-micrometer particles can be non-negligible, especially in the winter months (0.1% N–1.5% N in the sum of nitrate, ammonium and amines). This indicates that these smaller aliphatic amines can be important for the carbon and the nitrogen cycles in the remote marine environment
Target implosion uniformity in heavy ion fusion
It is well known that heavy ion beams (HIBs)
have a high controllability, a high driver energy
conversion efficiency and a high repetition rate.
Wobbling HIBs are easily available as the energy
driver in inertial fusion..
Researches on reactor core in Heavy ion inertial fusion
In Heavy ion inertial fusion (HIF), the issues
include the generation and transport of heavy
ion beam (HIB), the optimum pellet structure,
the realistic nuclear fusion reactor design, etc.
In this research, we have studied a conceptual
design of a nuclear fusion reactor system in HIF
(see Fig. 1)..
Target implosion uniformity in heavy ion fusion
It is well known that heavy ion beams (HIBs)
have a high controllability, a high driver energy
conversion efficiency and a high repetition rate.
Wobbling HIBs are easily available as the energy
driver in inertial fusion..
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