3,753 research outputs found
Spin correlated interferometry for polarized and unpolarized photons on a beam splitter
Spin interferometry of the 4th order for independent polarized as well as
unpolarized photons arriving simultaneously at a beam splitter and exhibiting
spin correlation while leaving it, is formulated and discussed in the quantum
approach. Beam splitter is recognized as a source of genuine singlet photon
states. Also, typical nonclassical beating between photons taking part in the
interference of the 4th order is given a polarization dependent explanation.Comment: RevTeX, 19 pages, 1 ps figure, author web page at
http://m3k.grad.hr/pavici
Bright filter-free source of indistinguishable photon pairs
We demonstrate a high-brightness source of pairs of indistinguishable photons
based on a type-II phase-matched doubly-resonant optical parametric oscillator
operated far below threshold. The cavity-enhanced down-conversion output of a
PPKTP crystal is coupled into two single-mode fibers with a mode coupling
efficiency of 58%. The high degree of indistinguishability between the photons
of a pair is demonstrated by a Hong-Ou-Mandel interference visibility of higher
than 90% without any filtering at an instantaneous coincidence rate of 450 000
pairs/s per mW of pump power per nm of down-conversion bandwidth. For the
degenerate spectral mode with a linewidth of 7 MHz at 795 nm a rate of 70
pairs/(s mW MHz) is estimated, increasing the spectral brightness for
indistinguishable photons by two orders of magnitude compared to similar
previous sources.Comment: 7 pages, 3 figure
Expressions of Hippocampal Mineralocorticoid Receptor (MR) and Glucocorticoid Receptor (GR) in the Single-Prolonged Stress-Rats
Post-traumatic stress disorder (PTSD) is a stress-related mental disorder caused by traumatic experience. Single-prolonged stress (SPS) is one of the animal models proposed for PTSD. Rats exposed to SPS showed enhanced inhibition of the hypothalamo-pituitary-adrenal (HPA) axis, which has been reliably reproduced in patients with PTSD. Mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) in the hippocampus regulate HPA axis by glucocorticoid negative feedback. Abnormalities in negative feedback are found in PTSD, suggesting that GR and MR might be involved in the pathophysiology of these disorders
Research on UBI auto insurance pricing model based on parameter adaptive SAPSO optimal fuzzy controller
Aiming at the problem of “dynamic” accurate determination of rates in UBI auto insurance pricing, this paper proposes a UBI auto insurance pricing model based on fuzzy controller and optimizes it with a parameter adaptive SASPO. On the basis of the SASPO algorithm, the movement direction of the particles can be mutated and the direction can be dynamically controlled, the inertia weight value is given by the distance between the particle and the global optimal particle, and the learning factor is calculated according to the change of the fitness value, which realizes the parameter in the running process. Effective self-adjustment. A five-dimensional fuzzy controller is constructed by selecting the monthly driving mileage, the number of violations, and the driving time at night in the UBI auto insurance data. The weights are used to form fuzzy rules, and a variety of algorithms are used to optimize the membership function and fuzzy rules and compare them. The research results show that, compared with other algorithms, the parameter adaptive SAPAO algorithm can calculate more reasonable, accurate and high-quality fuzzy rules and membership functions when processing UBI auto insurance data. The accuracy and robustness of UBI auto insurance rate determination can realize dynamic and accurate determination of UBI auto insurance rates
Electronic tuning and uniform superconductivity in CeCoIn5
We report a globally reversible effect of electronic tuning on the magnetic
phase diagram in CeCoIn_{5} driven by electron (Pt and Sn) and hole (Cd, Hg)
doping. Consequently, we are able to extract the superconducting pair breaking
component for hole and electron dopants with pressure and co-doping studies,
respectively. We find that these nominally non-magnetic dopants have a
remarkably weak pair breaking effect for a d-wave superconductor. The pair
breaking is weaker for hole dopants, which induce magnetic moments, than for
electron dopants. Furthermore, both Pt and Sn doping have a similar effect on
superconductivity despite being on different dopant sites, arguing against the
notion that superconductivity lives predominantly in the CeIn_{3} planes of
these materials. In addition, we shed qualitative understanding on the doping
dependence with density functional theory calculations.Comment: Accepted for publication in Phys. Rev. Lett. (October 1, 2012
Evolution of the Electronic Structure of 1T-CuxTiSe2
The electronic structure of a new charge-density-wave/ superconductor system,
1T-CuxTiSe2, has been studied by photoemission spectroscopy. A correlated
semiconductor band structure is revealed for the undoped case. With Cu doping,
the charge density wave is suppressed by the raising of the chemical potential,
while the superconductivity is enhanced by the enhancement of the density of
states. Moreover, the strong scattering at high doping might be responsible for
the suppression of superconductivity in that regime.Comment: 5 pages, 4 figure
Adaptive online deployment for resource constrained mobile smart clients
Nowadays mobile devices are more and more used as a platform for applications. Contrary to prior generation handheld devices configured with a predefined set of applications, today leading edge devices provide a platform for flexible and customized application deployment. However, these applications have to deal with the limitations (e.g. CPU speed, memory) of these mobile devices and thus cannot handle complex tasks. In order to cope with the handheld limitations and the ever changing device context (e.g. network connections, remaining battery time, etc.) we present a middleware solution that dynamically offloads parts of the software to the most appropriate server. Without a priori knowledge of the application, the optimal deployment is calculated, that lowers the cpu usage at the mobile client, whilst keeping the used bandwidth minimal. The information needed to calculate this optimum is gathered on the fly from runtime information. Experimental results show that the proposed solution enables effective execution of complex applications in a constrained environment. Moreover, we demonstrate that the overhead from the middleware components is below 2%
Palladium-doped hierarchical ZSM-5 for catalytic selective oxidation of allylic and benzylic alcohols
Hierarchical zeolites have the potential to provide a breakthrough in transport limitation, which hinders pristine microporous zeolites and thus may broaden their range of applications. We have explored the use of Pd-doped hierarchical ZSM-5 zeolites for aerobic selective oxidation (selox) of cinnamyl alcohol and benzyl alcohol to their corresponding aldehydes. Hierarchical ZSM-5 with differing acidity (H-form and Na-form) were employed and compared with two microporous ZSM-5 equivalents. Characterization of the four catalysts by X-ray diffraction, nitrogen porosimetry, NH 3 temperature-programmed desorption, CO chemisorption, high-resolution scanning transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray absorption spectroscopy allowed investigation of their porosity, acidity, as well as Pd active sites. The incorporation of complementary mesoporosity, within the hierarchical zeolites, enhances both active site dispersion and PdO active site generation. Likewise, alcohol conversion was also improved with the presence of secondary mesoporosity, while strong Brønsted acidity, present solely within the H-form systems, negatively impacted overall selectivity through undesirable self-etherification. Therefore, tuning support porosity and acidity alongside active site dispersion is paramount for optimal aldehyde production
Do Security Breaches Matter to Consumers?
Online security has been an important topic in electronic business. However, even the best IT security infrastructures cannot assure that cyber-attacks and malicious intrusions can be prevented. Therefore, it is important to know what is to be done when a security breach occurs, and how it influences consumers’ perceptions and behaviors. Via a survey of 258 respondents, this paper makes a first attempt to identify the relationships among security breach announcements, consumers’ perceived risks (including performance risk, financial risk, time risk and privacy risk), company reputation and a consumer’s intention to transact. Our key findings and implications are discussed
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