114 research outputs found
Modeling of a plasmonic nanosensor based on an open box-like metal cavity
No full textWe propose a plasmonic nanosensor based on an open box-like metal nanocavity. Surface plasmon polaritons (SPPs) excited at the metal/dielectric interface oscillate in the cavity, and then, plasmonic resonance modes are formed. Since the cavity is open, a part of the resonance light of the SPPs is scattered to light. By monitoring the shift in the scattering spectrum, the refractive index change of the sensed material can be derived. Because of the high reflectivity of the metallic walls, the sensitivity and figure of merit (FOM) are higher than those using single nanoparticle or nanoantenna. A sensitivity of 1046 nm/RIU (RIU denotes refractive index unit) and a FOM of 23.4 are derived for a 700 nm long and 350 nm high square cavity. Furthermore, the sensing area of the proposed sensor is smaller than 1 mu m(2) and the performance of the nanosensor can be further tuned by varying the cavity dimensions. The proposed sensor is well suited for observing small changes in biological and chemical reactions.National Natural Science Foundation of China [61377050, 11574011]; Research Fund for Doctoral Program of Higher Education [20130001110050]SCI(E)[email protected]
ChemInform Abstract: Cu‐Catalyzed Aerobic Oxidative Amidation of Aryl Alkyl Ketones with Azoles to Afford Tertiary Amides via Selective C—C Bond Cleavage.
No full textChemInform Abstract: Chemoselective Catalytic Reduction of Conjugated α,β‐Unsaturated Ketones to Saturated Ketones via a Hydroboration/Protodeboronation Strategy.
No full textNon-spectroscopic surface plasmon sensor with a tunable sensitivity
No full textWe demonstrate a non-spectroscopic surface plasmon sensor with a tunable sensitivity which is based on the relationship between the wave number of surface plasmon polaritons (SPPs) on metal film and the refractive index of the specimen in contact with the metal film. A change in the wave number of the SPPs results in a variation in the propagation angle of the leakage radiation of the SPPs. A reference light is used to interfere with the leakage radiation, and the refractive index of the specimen can be obtained by measuring the period of the interference fringes. The sensitivity of the sensor can be tuned by changing the incident direction of the reference light and this cannot be realized by conventional surface plasmon sensors. For a reference angle of 1.007 degrees, the sensitivity and resolution of the sensor are 4629 mu m/RIU (RIU stands for refractive index unit) and 3.6 x 10(-4) RIU, respectively. In addition, the sensor only needs a monochromatic light source, which simplifies the measurement setup and reduces the cost. (C) 2015 AIP Publishing LLC.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000348381000013&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, AppliedSCI(E)[email protected]
Learning connectivity and higher-order interactions in radial distribution grids
No full textTo perform any meaningful optimization task, distribution grid operators need to know the topology of their grids. Although power grid topology identification and verification has been recently studied, discovering instantaneous interplay among subsets of buses, also known as higher-order interactions in recent literature, has not yet been addressed. The system operator can benefit from having this knowledge when re-configuring the grid in real time, to minimize power losses, balance loads, alleviate faults, or for scheduled maintenance. Establishing a connection between the celebrated exact distribution flow equations and the so-called self-driven graph Volterra model, this paper puts forth a nonlinear topology identification algorithm, that is able to reveal both the edge connections as well as their higher-order interactions. Preliminary numerical tests using real data on a 47-bus distribution grid showcase the merits of the proposed scheme relative to existing alternatives.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Signal Processing System
Coupling between surface plasmon polaritons and transverse electric polarized light via L-shaped nano-apertures
No full textGiven that plasmonic fields are intrinsically transverse magnetic (TM), coupling surface plasmon polaritons (SPPs) and transverse electric (TE) polarized light, especially at nanoscale, remain challenging. We propose the use of L-shaped nano-apertures to overcome this fundamental limitation and enable coupling between SPPs and TE polarized light. Polarization conversion originates from the interference of two resonant modes excited in the nano-apertures and the nearly 180 degrees phase retardation between them. The experiments show that both TE-to-plasmon and plasmon-to-TE couplings can be implemented at the subwavelength scale. This discovery provides great freedom when manipulating light based on SPPs at the nanoscale and helps in using the energy of TE polarized light. (C) 2015 Optical Society of AmericaOpticsSCI(E)[email protected]
Molecular-oxygen-promoted Cu-catalyzed oxidative direct amidation of nonactivated carboxylic acids with azoles
No full textA copper-catalyzed oxidative direct formation of amides from nonactivated carboxylic acids and azoles with dioxygen as an activating reagent is reported. The azole amides were produced in good to excellent yields with a broad substrate scope. The mechanistic studies reveal that oxygen plays an essential role in the success of the amidation reactions with copper peroxycarboxylate as the key intermediate. Transamidation occurs smoothly between azole amide and a variety of amines
ChemInform Abstract: Molecular‐Oxygen‐Promoted Cu‐Catalyzed Oxidative Direct Amidation of Nonactivated Carboxylic Acids with Azoles.
No full textInfluence Maximizing and Local Influenced Community Detection Based on Multiple Spread Model
No full textIn independent cascade model, an active node has only one chance to activate its neighbors, while in reality an active node has many chances to activate its neighbors. We propose an influence diffusion model called multiple spread model, in which an active node has many activation chances. We prove that influence maximizing problem with the proposed model is submodular and monotone, which means greedy algorithm provides (1-1/e) approximation to optimal solution. However, computation time costs much due to Monte Carlo simulation in greedy algorithm. We propose a two-phase method which leverages community information to find seeds. In order to evaluate influence of a particular node, we also propose a definition of local influenced community as well as an algorithm called LICD to detect local influenced community. Experiments show that the proposed model and algorithms are both efficient and effective in problems of influence maximizing and local influenced community detection.Computer Science, Artificial IntelligenceComputer Science, Information SystemsEICPCI-S(ISTP)
- …
