Sökresultat

Filtyp

Din sökning på "*" gav 534719 sökträffar

Ultrafast photoisomerization of pinacyanol : Watching an excited state reaction transiting from barrier to barrierless forms

Photoisomerization of 1,1′-diethyl-2,2′-carbocyanine iodide (pinacyanol) in alcohols was investigated by means of femtosecond time-resolved absorption spectroscopy. Only one out of two possible types of photoisomer was found. Viscosity-dependent kinetics indicate that the excited state dynamics consist of two parts, associated with a barrier-crossing observed in the blue side of stimulated emissio

ZrO2 and HfO2 dielectrics on (001) n-InAs with atomic-layer-deposited in situ surface treatment

The electrical properties of ZrO2 and HfO2 gate dielectrics on n-InAs were evaluated. Particularly, an in situ surface treatment method including cyclic nitrogen plasma and trimethylaluminum pulses was used to improve the quality of the high-κ oxides. The quality of the InAs-oxide interface was evaluated with a full equivalent circuit model developed for narrow band gap metal-oxide-semiconductor (

Realising innovation opportunities in sub-Saharan Africa

The aim of the document is to identify and discuss a number of growth paths that might be explored to promote innovationdriven development in Sub-Saharan Africa. The document adopts a broad perspective of innovation, examining framework conditions, fundamental prerequisites, drivers and focal areas for innovation. The document addresses a spectrum of issues andtopics ranging from regional and glob

Scaling of Vertical InAs–GaSb Nanowire Tunneling Field-Effect Transistors on Si

We demonstrate improved performance due to enhanced electrostatic control achieved by diameter scaling and gate placement in vertical InAs-GaSb tunneling field-effect transistors integrated on Si substrates. The best subthreshold swing, 68 mV/decade at VDS=0.3 V, was achieved for a device with 20-nm InAs diamter. The on-current for the same device was 35 µA/µm at VGS=0.5 V and VDS=0.5 V. The fabri

Strategic self-ignorance

We examine strategic self-ignorance—the use of ignorance as an excuse toover-indulge in pleasurable activities that may be harmful to one’s future self. Our model shows that guilt aversion provides a behavioral rationale for present-biased agents to avoid information about negative future impacts of such activities. We then confront our model with data from an experiment using prepared, restaurantWe examine strategic self-ignorance—the use of ignorance as an excuse to over-indulge in pleasurable activities that may be harmful to one’s future self. Our model shows that guilt aversion provides a behavioral rationale for present-biased agents to avoid information about negative future impacts of such activities. We then confront our model with data from an experiment using prepared, restauran

Designing a social and assistive robot for seniors

Background: The development of social assistive robots is an approach with the intention of preventing and detecting falls among seniors. There is a need for a relatively low-cost mobile robot with an arm and a gripper which is small enough to navigate through private homes. Material and methods: User requirements of a social assistive robot were collected using workshops, a questionnaire and inte

Kidney Exchange over the Blood Group Barrier

This paper investigates a pairwise kidney exchange program that includes patient-donor pairs in which the patients can receive a kidney across the blood group barrier from their own donors. Patients in such pairs gain strictly by an exchange if they are matched to a fully compatible donor. We study the set of priority matchings where the number of patients matched to fully compatible donors is max

Comparison between ultrafiltration and nanofiltration hollow-fiber membranes for removal of natural organic matter : A pilot study

Increasing trends of natural organic matter (NOM) in surface water in Nordic countries may cause future problems for drinking water producers. Emerging membrane technology, such as ultrafiltration (UF) and nanofiltration (NF), has the potential to produce safe drinking water of good quality from sources with high organic concentrations. In the present pilot study, surface water from three sources

An Auction with Approximated Bidder Preferences - When an Auction has to be Quick

This paper presents a combinatorial auction which is of particular interest when short completion times are of importance. It is based on a method for approximating the bidders' preferences over two types of items when complementarity between the two may exist. The resulting approximated preference relation is shown to be complete and transitive at any given price vector. It is shown that an appro

Gaia reference frame amid quasar variability and proper motion patterns in the data

Context. Gaia’s very accurate astrometric measurements will allow the optical realisation of the International Celestial Reference System to be improved by a few orders of magnitude. Several sets of quasars are used to define a kinematically stable non-rotating reference frame with the barycentre of the solar system as its origin. Gaia will also observe a large number of galaxies. Although they ar

"Document of the Month" - a regular feature of the PRC History Group website

As of February 2014, a regular monthly contribution to the PRC History Group's website (prchistory.org/document-of-the-month) comprising the selection and reproduction of a unique archival record from the first decades of the People's Republic of China with added contextualizing, critical, and explanatory commentary highlighting the significance and importance of the document in question.

Crosstalk Mitigation for LTE-over-Copper in Downlink Direction

Radio-over-copper is a niche idea that has potential to become a cornerstone in the deployment of dense 5G networks. We address one of the remaining hurdles and present an architecture for transparent crosstalk mitigation in LTE-over-copper systems. By taking advantage of reference symbols present in the downlink LTE signals we propose two methods for estimating the copper channel. System performa

A comparison of Rosenbrock and ESDIRK methods combined with iterative solvers for unsteady compressible flows

In this article, we endeavour to find a fast solver for finite volume discretizations for compressible unsteady viscous flows. Thereby, we concentrate on comparing the efficiency of important classes of time integration schemes, namely time adaptive Rosenbrock, singly diagonally implicit (SDIRK) and explicit first stage singly diagonally implicit Runge-Kutta (ESDIRK) methods. To make the compariso