Search results for "Citation"
showing 10 items of 1710 documents
Theoretical characterization of the absorption spectra of phenanthrene and its radical cation
2003
The vertical absorption spectra of phenanthrene and its radical cation have been studied theoretically by means of a multiconfigurational second-order perturbation approach. Singlet-singlet transition energies and oscillator strengths, and singlet-triplet excitation energies have been studied in the absorption spectrum of phenanthrene up to 6 eV. The absorption spectrum of the pehnanthrene radical cation has been computed up to 3.4 eV. The results obtained confirm previous assignments and also lead to new interpretations of the main features of the spectra of these systems.
On the vertical excitation energy of cyclopentadiene
2004
The vertical excitation energy for the lowest valence pi--pi(*) transition of cyclopentadiene is investigated. Using a combination of high-level theoretical methods and spectroscopic simulations, the vertical separation at the ground state geometry is estimated to be 5.43+/-0.05 eV. This value is intermediate between those calculated with coupled-cluster and multireference perturbation theory methods and is about 0.13 eV higher than the observed maximum in the absorption profile.
Comparison of the molecular structure and spectra of benzene and borazine
1970
Ab initio SCF MO and CI calculations for two different gaussian basis sets are carried out for the isoelectronic molecules benzene C6H6 and borazine B3N3H3 in order to investigate the effect of increasing the flexibility in the representation of their respective π systems. In the process it is found from comparison of orbital charge density contour diagrams and inner shell orbital energies of borazine with analogous data for other systems that the BN bonds of this compound are considerably less polar (B+N−) than that of ammonia borane BNH6 (B−N+). CI calculations employing the larger basis set produce generally better agreement with the experimental transition energies of benzene than do th…
Excited states of [3.3](4,4')biphenylophane: the role of charge-transfer excitations in dimers with pi-pi interaction.
2010
The singlet and triplet electronic excitation manifold of [3.3](4,4')biphenylophane (BPP), an intramolecular dimer, and 4,4'-dimethylbiphenyl (DMBP), the corresponding monomer, has been analyzed by employing the approximate coupled-cluster singles and doubles model (CC2). The calculated triplet-triplet and singlet-singlet transient absorption spectra show good agreement with recent experimental results. The calculations suggest a strong interaction of the two biphenyl moieties of BPP in the first singlet and triplet excited states due to the overlapping pi-electron systems, and Forster-Dexter theory for weak coupling cannot be applied. Both the first excited singlet and triplet states of BP…
Removal of Chromophore-proximal Polar Atoms Decreases Water Content and Increases Fluorescence in a Near Infrared Phytofluor
2015
Genetically encoded fluorescent markers have revolutionized cell and molecular biology due to their biological compatibility, controllable spatiotemporal expression, and photostability. To achieve in vivo imaging in whole animals, longer excitation wavelength probes are needed due to the superior ability of near infrared light to penetrate tissues unimpeded by absorbance from biomolecules or autofluorescence of water. Derived from near infrared-absorbing bacteriophytochromes, phytofluors are engineered to fluoresce in this region of the electromagnetic spectrum, although high quantum yield remains an elusive goal. An invariant aspartate residue is of utmost importance for photoconversion in…
Highly cited educational technology journal articles: A descriptive and critical analysis
2022
Citations are valuable capital in the academy as the number of citations is the most frequently used indicator in evaluating the quality of papers, journals, researchers, and universities. Thus, the characteristics of highly cited articles (HCA) have become a common research topic but the approach has been mainly descriptive with no profound critical reflection of what kind of research is cited, where the research is from, where the research is published, and what do these things mean for edtech research. This paper contributes to this need by providing a descriptive and critical analysis of 200 highly cited articles from 10 edtech journals. To summarize the key findings, a ‘typical’ edtech…
Revising the history of Nitchevo with text archives
2022
This article focuses on the way nitchevo, a nineteenth-century Russian borrowing, was adopted into the English language. In order to investigate the history of the word, six digital text archives were considered. The results of the research are promising: not only do they allow one to trace antedatings for both senses, which updates the treatment of nitchevo in the Oxford English Dictionary (OED), but they also shed light on its semantic development, spelling variation, and route of transmission. Tellingly, albeit unsurprisingly, the evidence suggests that the press is responsible for boosting the recognition of the word on both sides of the Atlantic. All this indicates that the potential o…
Sustainability in Hospitality Marketing during the COVID-19 Pandemic. Content Analysis of Consumer Empirical Research
2021
This study performs content analysis of consumer empirical research dealing with sustainability issues in hospitality marketing literature during the outbreak of COVID-19. Papers published in the Social Sciences Citation Index (SSCI) ranked hospitality journals from January 2020 up to and including May 2021 are reviewed. The total of 46 papers met the search criteria and were subject to content analysis. The reviewed papers are classified based on research topics, variables, and themes
Dagens Rødhette i en flerkulturell kontekst – mulighet for en ny identitet?
2013
The starting point for this article is the tendency in recent Norwegian children’s and Ya fiction to thematize cultural encounters in an increasingly multicultural and globalized world. The picturebook Little Miss Eye Flap ( Skylappjenta , 2009) written by the Pakistani-Norwegian author and actor Iram Haq and illustrated by Endre Skandfer, presents a modern version of traditional folktales such as Little Red Riding Hood and Rapunzel . However, the traditional structure of home – away – home gives particular emphasis to the phase of homelessness, not providing any safe return to harmony. This condition of liminal space between cultures is discussed in light of the concepts of reflexive ident…
Origin of the Red Sites and Energy Transfer Rates in Single MEH-PPV Chains at Low Temperature
2011
Single poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) molecules dispersed in thin poly(methylmethacrylate) films have been investigated by fluorescence emission, excitation and time-resolved spectroscopy at 1.2 K. For the molecular weight studied (∼200 kDa) a bimodal distribution of emission maxima is observed. Based on a comparison of the spectroscopic properties of blue and red sites and on polarisation-resolved measurements, we argue in agreement with recent quantum-chemical calculations that the red subpopulation most probably does not arise from interchromophoric excitation delocalisation but is to be attributed to longer chromophoric units originating from orde…