6,695 research outputs found
Observation of Exciton-Phonon Sideband in Individual Metallic Single-Walled Carbon Nanotubes
Single-walled carbon nanotubes (SWCNTs) are quasi-one-dimensional systems
with poor Coulomb screening and enhanced electron-phonon interaction, and are
good candidates for excitons and exciton-phonon couplings in metallic state.
Here we report back scattering reflection experiments on individual metallic
SWCNTs. An exciton-phonon sideband separated by 0.19 eV from the first optical
transition peak is observed in a metallic SWCNT of chiral index (13,10), which
provides clear evidences of excitons in metallic SWCNTs. A static dielectric
constant of 10 is estimated from the reflectance spectrum.Comment: 5 pages, 3 figures; typos corrected, references updated, text
re-arrange
Collective quantum phase slips in multiple nanowire junctions
Realization of robust coherent quantum phase slips represents a significant
experimental challenge. Here we propose a new design consisting of multiple
nanowire junctions to realize a phase-slip flux qubit. It admits good
tunability provided by gate voltages applied on superconducting islands
separating nanowire junctions. In addition, the gates and junctions can be
identical or distinct to each other leading to symmetric and asymmetric setups.
We find that the asymmetry can improve the performance of the proposed device,
compared with the symmetric case. In particular, it can enhance the effective
rate of collective quantum phase slips. Furthermore, we demonstrate how to
couple two such devices via a mutual inductance. This is potentially useful for
quantum gate operations. Our investigation on how symmetry in multiple nanowire
junctions affects the device performance should be useful for the application
of phase-slip flux qubits in quantum information processing and quantum
metrology.Comment: 12 pages, 6 figure
DESIGN AND IMPLEMENTATION OF A WEB INTERACTIVE THEMATIC CARTOGRAPHY METHOD BASED ON A WEB SERVICE CHAIN
There is a tendency toward the creation of thematic maps on the web in the ongoing development of cartographic technology. However, automatically creating maps through the web and creating interactive web maps are two challenges associated with this field. To solve these problems, a web thematic cartography method based on a web service chain is presented here. Automated cartography is performed through knowledge-based web cartographic services, and interacting with the services is possible. The method is implemented in the construction of a urban thematic atlas in Shenzhen, China that is dedicated to supporting decision making for urban planning and public participatory thematic map making on the web.
Poly[tetra-μ1,1-azido-bis(μ2-pyrimidine-2-carboxylato)tricopper(II)]
In the title compound, [Cu3(C5H3N2O2)2(N3)4]n, one of the CuII atoms lies on an inversion centre and is octahedrally coordinated by two bidentate chelating pyrimidine-2-carboxylate ligands and two azide anions, each of which gives an N:N-bridge to the second inversion-related CuII centre in the formula unit. The second CuII atom is five-coordinated with a distorted square-pyramidal coordination sphere comprising a single bidentate chelating pyrimidine-2-carboxylate anion and three azide N anions, two of which doubly bridge centrosymmetric CuII centres, giving a two-dimensional network structure extending parallel to (010)
Is hyperuricemia an independent risk factor for new-onset chronic kidney disease?: a systematic review and meta-analysis based on observational cohort studies
This article discusses the role of interrogation in intelligence during the Second World War, and it focuses on the importance of culture in the collection of Human Intelligence in the European theatre of operation. It argues that cultural issues, including but not limited to language knowledge, provided an added value to interrogation, interviewing and questioning during and after the Second World War, for example through the employment of native speakers, in particular former refugees and enemy aliens. The article also highlights some of the flaws involved in this process, which led to bad prisoner handling and therefore bad intelligence collection. It also tries to complement archival sources with personal accounts and oral histories in order to achieve a deeper understanding of the role of the human being in the collection of intelligence through interrogation and questioning
New nematode species from the continental slope of New Zealand (Chromadorea, Microlaimida, and Chromadorida), and unexpected placement of the genus Molgolaimus Ditlevsen, 1921
Abstract(#br)The current nematode classification comprises three primarily marine basal Chromadorean orders: the Microlaimida Leduc et al., 2018; Desmodorida De Coninck, 1965; and Chromadorida Chitwood, 1933. The phylogenetic placement of several taxa within these orders, however, is unclear due to the paucity of taxonomically informative morphological characters for high-level classification and is yet to be tested by molecular phylogenetic analyses due to the absence of molecular sequences. Here, we describe Molgolaimus kaikouraensis sp. nov. and Aponema pseudotorosum sp. nov. from the continental slope of New Zealand and investigate phylogenetic relationships of these species and that of the rare desmodorid genera Onepunema and Pseudonchus , using SSU phylogenetic analyses for the..
Realization of Zero-Refractive-Index Lens with Ultralow Spherical Aberration
Optical complex materials offer unprecedented opportunity to engineer
fundamental band dispersion which enables novel optoelectronic functionality
and devices. Exploration of photonic Dirac cone at the center of momentum space
has inspired an exceptional characteristic of zero-index, which is similar to
zero effective mass in fermionic Dirac systems. Such all-dielectric zero-index
photonic crystals provide an in-plane mechanism such that the energy of the
propagating waves can be well confined along the chip direction. A
straightforward example is to achieve the anomalous focusing effect without
longitudinal spherical aberration, when the size of zero-index lens is large
enough. Here, we designed and fabricated a prototype of zero-refractive-index
lens by comprising large-area silicon nanopillar array with plane-concave
profile. Near-zero refractive index was quantitatively measured near 1.55 um
through anomalous focusing effect, predictable by effective medium theory. The
zero-index lens was also demonstrated to perform ultralow longitudinal
spherical aberration. Such IC compatible device provides a new route to
integrate all-silicon zero-index materials into optical communication, sensing,
and modulation, and to study fundamental physics on the emergent fields of
topological photonics and valley photonics.Comment: 14 pages, 4 figure
- …