145 research outputs found
Conductance Switching by Light and Electric Field in New Azobenzene Derivatives-Gold Nano-Particle Self-Assembled Networks (NPSAN)
Monitoring conductance switching by light in Azobenzene derivative-Gold Nano-Particle Self-Assembled Networks
Synthesis and Characterization of Gold Nanoparticles Functionalized with Electropolymerizable or Optically Switchable π-Conjugated Systems
International audienc
New strategies for sustainable fisheries management: A case study of Atlantic salmon
This briefing paper considers the alarming declines in fish stocks in recent years, and how holistic, integrated approaches can help manage fish stocks within biologically sustainable limits. Using Atlantic salmon as a case study, the authors highlight the challenges facing fisheries management and conservation, and the implications for policy and management
Systematic variation in food web body-size structure linked to external subsidies.
The relationship between body mass (M) and size class abundance (N) depicts patterns of community structure and energy flow through food webs. While the general assumption is that M and N scale linearly (on log-log axes), nonlinearity is regularly observed in natural systems, and is theorized to be driven by nonlinear scaling of trophic level (TL) with M resulting in the rapid transfer of energy to consumers in certain size classes. We tested this hypothesis with data from 31 stream food webs. We predicted that allochthonous subsidies higher in the web results in nonlinear M-TL relationships and systematic abundance peaks in macroinvertebrate and fish size classes (latter containing salmonids), that exploit terrestrial plant material and terrestrial invertebrates, respectively. Indeed, both M-N and M-TL significantly deviated from linear relationships and the observed curvature in M-TL scaling was inversely related to that observed in M-N relationships. Systemic peaks in M-N, and troughs in M-TL occurred in size classes dominated by generalist invertebrates, and brown trout. Our study reveals how allochthonous resources entering high in the web systematically shape community size structure and demonstrates the relevance of a generalized metabolic scaling model for understanding patterns of energy transfer in energetically 'open' food webs
A New Photomechanical Molecular Switch Based on a Linear {\pi}-Conjugated System
We report the electronic transport properties of a new photo-addressable
molecular switch. The switching process relies on a new concept based on linear
{\pi}-conjugated dynamic systems, in which the geometry and hence the
electronic properties of an oligothiophene chain can be reversibly modified by
the photochemical trans-cis isomerization of an azobenzene unit fixed in a
lateral loop. Electron transport measurements through self-assembled monolayers
on gold, contacted with eGaIn top contact, show switching with a conductance
ratio up to 1E3. Ab initio calculations have been used to identify the most
energetically stable conformations of the molecular switch, the corresponding
calculated conductances qualitatively explain the trend observed in the
photo-switching experiments.Comment: Full manuscript and supporting information, J. Phys. Chem.
C,published on line (2017
A New Photomechanical Molecular Switch Based on a Linear {\pi}-Conjugated System
We report the electronic transport properties of a new photo-addressable
molecular switch. The switching process relies on a new concept based on linear
{\pi}-conjugated dynamic systems, in which the geometry and hence the
electronic properties of an oligothiophene chain can be reversibly modified by
the photochemical trans-cis isomerization of an azobenzene unit fixed in a
lateral loop. Electron transport measurements through self-assembled monolayers
on gold, contacted with eGaIn top contact, show switching with a conductance
ratio up to 1E3. Ab initio calculations have been used to identify the most
energetically stable conformations of the molecular switch, the corresponding
calculated conductances qualitatively explain the trend observed in the
photo-switching experiments.Comment: Full manuscript and supporting information, J. Phys. Chem.
C,published on line (2017
Exclusive Strategy for Generalization Algorithms in Micro-data Disclosure
Abstract. When generalization algorithms are known to the public, an adver-sary can obtain a more precise estimation of the secret table than what can be deduced from the disclosed generalization result. Therefore, whether a general-ization algorithm can satisfy a privacy property should be judged based on such an estimation. In this paper, we show that the computation of the estimation is inherently a recursive process that exhibits a high complexity when generaliza-tion algorithms take a straightforward inclusive strategy. To facilitate the design of more efficient generalization algorithms, we suggest an alternative exclusive strategy, which adopts a seemingly drastic approach to eliminate the need for recursion. Surprisingly, the data utility of the two strategies are actually not com-parable and the exclusive strategy can provide better data utility in certain cases.
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