1,720,971 research outputs found
Micromechanical Bolometers for Subterahertz Detection at Room Temperature
Full text linkFast room-temperature imaging at terahertz (THz) and subterahertz (sub-THz) frequencies is an interesting technique that could unleash the full potential of plenty of applications in security, healthcare, and industrial production. In this Letter, we introduce micromechanical bolometers based on silicon nitride trampoline membranes as broad-range detectors down to sub-THz frequencies. They show, at the longest wavelengths, room-temperature noise-equivalent powers comparable to those of state-of-the-art commercial devices (∼100 pW Hz–1/2), which, along with the good operation speed and the easy, large-scale fabrication process, could make the trampoline membrane the next candidate for cheap room-temperature THz imaging and related applications
In-situ Transmission Electron Microscopy Studies on Graphene
No full textCasimir PhD Series, Delft-Leiden 2017-1 This research was financially supported by ERC: project 267922, "NemlnTEM"QN/Zandbergen La
Controlling Defects in Graphene for Optimizing the Electrical Properties of Graphene Nanodevices
No full textStructural defects strongly impact the electrical transport properties of graphene nanostructures. In this Perspective, we give a brief overview of different types of defects in graphene and their effect on transport properties. We discuss recent experimental progress on graphene self-repair of defects, with a focus on in situ transmission electron microscopy studies. Finally, we present the outlook for graphene self-repair and in situ experiments
1/f Noise in Graphene nanopores
No full textSeventh Framework Programme (FP7)Supramolecular & Biomaterials Chemistr
Probing DNA Translocations with Inplane Current Signals in a Graphene Nanoribbon with a Nanopore
No full textMany theoretical
studies predict that DNA sequencing should be
feasible by monitoring the transverse current through a graphene nanoribbon
while a DNA molecule translocates through a nanopore in that ribbon.
Such a readout would benefit from the special transport properties
of graphene, provide ultimate spatial resolution because of the single-atom
layer thickness of graphene, and facilitate high-bandwidth measurements.
Previous experimental attempts to measure such transverse inplane
signals were however dominated by a trivial capacitive response. Here,
we explore the feasibility of the approach using a custom-made differential
current amplifier that discriminates between the capacitive current
signal and the resistive response in the graphene. We fabricate well-defined
short and narrow (30 nm × 30 nm) nanoribbons with a 5 nm nanopore
in graphene with a high-temperature scanning transmission electron
microscope to retain the crystallinity and sensitivity of the graphene.
We show that, indeed, resistive modulations can be observed in the
graphene current due to DNA translocation through the nanopore, thus
demonstrating that DNA sensing with inplane currents in graphene nanostructures
is possible. The approach is however exceedingly challenging due to
low yields in device fabrication connected to the complex multistep
device layout
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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