Signal processing in high speed OTDM networks

This paper presents the design and experimental results of an optical packet-switching testbed capable of performing message routing with single wavelength TDM packet bit rates as high as 100 Gb/s

Disorderless quasi-localization of polar gases in one-dimensional lattices

One-dimensional polar gases in deep optical lattices present a severely constrained dynamics due to the interplay between dipolar interactions, energy conservation, and finite bandwidth. The appearance of dynamically-bound nearest-neighbor dimers enhances the role of the $1/r^3$ dipolar tail, resulting, in the absence of external disorder, in quasi-localization via dimer clustering for very low densities and moderate dipole strengths. Furthermore, even weak dipoles allow for the formation of self-bound superfluid lattice droplets with a finite doping of mobile, but confined, holons. Our results, which can be extrapolated to other power-law interactions, are directly relevant for current and future lattice experiments with magnetic atoms and polar molecules.Comment: 5 + 2 Page

Assessing effects of permafrost thaw on C fluxes based on multiyear modeling across a permafrost thaw gradient at Stordalen, Sweden

Northern peatlands in permafrost regions contain a large amount of organic carbon (C) in the soil. Climate warming and associated permafrost degradation are expected to have significant impacts on the C balance of these ecosystems, but the magnitude is uncertain. We incorporated a permafrost model, Northern Ecosystem Soil Temperature (NEST), into a biogeochemical model, DeNitrificationDeComposition (DNDC), to model C dynamics in highlatitude peatland ecosystems. The enhanced model was applied to assess effects of permafrost thaw on C fluxes of a subarctic peatland at Stordalen, Sweden. DNDC simulated soil freeze–thaw dynamics, net ecosystem exchange of CO2 (NEE), and CH4 fluxes across three typical land cover types, which represent a gradient in the process of ongoing permafrost thaw at Stordalen. Model results were compared with multiyear field measurements, and the validation indicates that DNDC was able to simulate observed differences in seasonal soil thaw, NEE, and CH4 fluxes across the three land cover types. Consistent with the results from field studies, the modeled C fluxes across the permafrost thaw gradient demonstrate that permafrost thaw and the associated changes in soil hydrology and vegetation not only increase net uptake of C from the atmosphere but also increase the annual to decadal radiative forcing impacts on climate due to increased CH4 emissions. This study indicates the potential of utilizing biogeochemical models, such as DNDC, to predict the soil thermal regime in permafrost areas and to investigate impacts of permafrost thaw on ecosystem C fluxes after incorporating a permafrost component into the model framework

Efficient quantum cryptography network without entanglement and quantum memory

An efficient quantum cryptography network protocol is proposed with d-dimension polarized photons, without resorting to entanglement and quantum memory. A server on the network, say Alice, provides the service for preparing and measuring single photons whose initial state are |0>. The users code the information on the single photons with some unitary operations. For preventing the untrustworthy server Alice from eavesdropping the quantum lines, a nonorthogonal-coding technique (decoy-photon technique) is used in the process that the quantum signal is transmitted between the users. This protocol does not require the servers and the users to store the quantum state and almost all of the single photons can be used for carrying the information, which makes it more convenient for application than others with present technology. We also discuss the case with a faint laser pulse.Comment: 4 pages, 1 figures. It also presented a way for preparing decoy photons without a sinigle-photon sourc

Mössbauer hyperfine parameters of iron species in the course of Geobacter-mediated magnetite mineralization

Amorphous ferric iron species (ferrihydrite or akaganeite of <5 nm in size) is the only known solid ferric iron oxide that can be reductively transformed by dissimilatory iron-reducing bacteria to magnetite completely. The lepidocrocite crystallite can be transformed into magnetite in the presence of abiotic Fe(II) at elevated pH or biogenic Fe(II) with particular growth conditions. The reduction of lepidocrocite by dissimilatory iron-reducing bacteria has been widely investigated showing varying results. Vali et al. (Proc Natl Acad Sci USA 101:16121-16126, 2004) captured a unique biologically mediated mineralization pathway where the amorphous hydrous ferric oxide transformed to lepidocrocite was followed by the complete reduction of lepidocrocite to single-domain magnetite. Here, we report the 57Fe Mössbauer hyperfine parameters of the time-course samples reported in Vali et al. (Proc Natl Acad Sci USA 101:16121-16126, 2004). Both the quadrupole splittings and linewidths of Fe(III) ions decrease consistently with the change of aqueous Fe(II) and transformations of mineral phases, showing the Fe(II)-mediated gradual regulation of the distorted coordination polyhedrons of Fe 3+ during the biomineralization process. The aqueous Fe(II) catalyzes the transformations of Fe(III) minerals but does not enter the mineral structures until the mineralization of magnetite. The simulated abiotic reaction between Fe(II) and lepidocrocite in pH-buffered, anaerobic media shows the simultaneous formation of green rust and its gradual transformation to magnetite plus a small fraction of goethite. We suggested that the dynamics of Fe(II) supply is a critical factor for the mineral transformation in the dissimilatory iron-reducing cultures. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

Quantum secret sharing between m-party and n-party with six states

We propose a quantum secret sharing scheme between $m$-party and $n$-party using three conjugate bases, i.e. six states. A sequence of single photons, each of which is prepared in one of the six states, is used directly to encode classical information in the quantum secret sharing process. In this scheme, each of all $m$ members in group 1 choose randomly their own secret key individually and independently, and then directly encode their respective secret information on the states of single photons via unitary operations, then the last one (the $m$th member of group 1) sends $1/n$ of the resulting qubits to each of group 2. By measuring their respective qubits, all members in group 2 share the secret information shared by all members in group 1. The secret message shared by group 1 and group 2 in such a way that neither subset of each group nor the union of a subset of group 1 and a subset of group 2 can extract the secret message, but each whole group (all the members of each group) can. The scheme is asymptotically 100% in efficiency. It makes the Trojan horse attack with a multi-photon signal, the fake-signal attack with EPR pairs, the attack with single photons, and the attack with invisible photons to be nullification. We show that it is secure and has an advantage over the one based on two conjugate bases. We also give the upper bounds of the average success probabilities for dishonest agent eavesdropping encryption using the fake-signal attack with any two-particle entangled states. This protocol is feasible with present-day technique.Comment: 7 page

Is Perceived Creativity-reward Contingency Good for Creativity? The Role of Challenge and Threat Appraisals

To address the complex effect of perceived reward for creativity on creative performance, we examined the role of cognitive appraisal as an individual difference variable. An individual's appraisal of reward for creativity, including challenge appraisal (perceived potential for recognition, growth, or mastery) and threat appraisal (perceived potential for revealing incompetence and damaging self-respect), is hypothesized to shape the effects of perceived reward for creativity. We further expect creativity-related intrinsic motivation to play a mediating role in the perceived reward-creativity relationship. The results of a three-wave field study showed that when challenge appraisal was high, perceived reward was positively related to creative performance through creativity-related intrinsic motivation, whereas when threat appraisal was high, perceived reward was negatively related to creative performance through creativity-related intrinsic motivation. A similar analysis showed that intrinsic task motivation was not able to channel the moderating effect of perceived reward and individual appraisal on creative performance

Event-triggered H∞ position control of receiver coil for effective mobile wireless charging of electric vehicles

The emergence of dynamic wireless charging technologies brings about new possibilities for on-road real-time charging of electric vehicles in solving the battery bottleneck for the mass roll-out of electric vehicles worldwide. In this new area, charging efficiency is one of the most important issues to be addressed for on-road wireless charging. While most current research mainly focuses on the electronic power design of the charging system, little has been done to improve charging efficiency through real-time mechanical control. In this paper, a switch control strategy based on an event-triggered mechanism is proposed, to improve the charging efficiency when an electric vehicle moves along a power supply road track. An H∞ control problem is formulated and sufficient stabilization criteria are derived in the form of linear matrix inequalities when the electric vehicle derails from the effective charging range. Numerical simulation confirms that the proposed control approach outperforms the general state feedback control method. The developed control strategy is applied to control a newly built electric vehicle wireless charging test platform with desirable control performance

Efficient Multi-Party Quantum Secret Sharing Schemes

In this work, we generalize the quantum secret sharing scheme of Hillary, Bu\v{z}ek and Berthiaume[Phys. Rev. A59, 1829(1999)] into arbitrary multi-parties. Explicit expressions for the shared secret bit is given. It is shown that in the Hillery-Bu\v{z}ek-Berthiaume quantum secret sharing scheme the secret information is shared in the parity of binary strings formed by the measured outcomes of the participants. In addition, we have increased the efficiency of the quantum secret sharing scheme by generalizing two techniques from quantum key distribution. The favored-measuring-basis Quantum secret sharing scheme is developed from the Lo-Chau-Ardehali technique[H. K. Lo, H. F. Chau and M. Ardehali, quant-ph/0011056] where all the participants choose their measuring-basis asymmetrically, and the measuring-basis-encrypted Quantum secret sharing scheme is developed from the Hwang-Koh-Han technique [W. Y. Hwang, I. G. Koh and Y. D. Han, Phys. Lett. A244, 489 (1998)] where all participants choose their measuring-basis according to a control key. Both schemes are asymptotically 100% in efficiency, hence nearly all the GHZ-states in a quantum secret sharing process are used to generate shared secret information.Comment: 7 page