Search results for "Roca"
showing 10 items of 1893 documents
Cardiorespiratory information dynamics during mental arithmetic and sustained attention
2015
An analysis of cardiorespiratory dynamics during mental arithmetic, which induces stress, and sustained attention was conducted using information theory. The information storage and internal information of heart rate variability (HRV) were determined respectively as the self-entropy of the tachogram, and the self-entropy of the tachogram conditioned to the knowledge of respiration. The information transfer and cross information from respiration to HRV were assessed as the transfer and cross-entropy, both measures of cardiorespiratory coupling. These information-theoretic measures identified significant nonlinearities in the cardiorespiratory time series. Additionally, it was shown that, alt…
De las aulas universitarias a la red. Un proyecto innovador aplicado al aprendizaje y difusión de la literatura catalana barroca
2017
[EN] This paper focuses on the description and analysis of an innovative educational experience in the field of the Baroque Catalan Literature. This experience, which has recently been implemented as a pilot test in universities thanks to the a project of innovative teaching, concentrates on the use of tecnological resources and the development of an initial project of Transmedia Storytelling to foster the motivation of students and generate a more meaningful learning. This case study is grounded in the implementation of the resources and active methodologies of the course on Early Modern Catalan Literature, traditionally based on conventional educational strategies and despised by the hist…
Electrocaloric Effect in (1−x)(0.8Na0.5Bi0.5TiO3-0.2BaTiO3)−xCaTiO3 Solid Solutions at High Electric Fields
2022
This research was funded by the Latvian Science Council Fund, grant number lzp-2020/2-0080. The Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme, grant number 739508.
Toward Near-Infrared Emission in Pt(II)-Cyclometallated Compounds: From Excimers’ Formation to Aggregation-Induced Emission
2023
Two series of Pt(II)-cyclometallated compounds containing N^C^N tridentate and alkynyl-chromophore ligands have been synthesized and structurally characterized. The N^C^N ligands differ on the presence of R1 = H or F in the central aromatic ring, while six different chromophores have been introduced to the alkynyl moiety. Single-crystal X-ray structures for some of the compounds reveal the presence of weak intermolecular contacts responsible for the formation of some dimers or aggregates. The photophysical characterization shows the presence of two emission bands in solution assigned to the 3π–π* transition from the N^C^N ligands mixed with 3MLCT/3ILCT transitions (higher energy band) in de…
Die symmetrischen Cyclooctadienine: 1,5‐Cyclooctadien‐3‐in und 1,3‐Cyclooctadien‐6‐in
1985
Die Titelverbindungen 16 und 17, hoch gespannte Kohlenwasserstoffe aus der C8H8-Reihe, konnen auf sechs- bzw. siebenstufigen Synthesewegen aus 1,5-Cyclooctadien (1) bzw. Cyclooctatetraen (2) hergestellt und in reiner Form isoliert werden. Ihre Stabilitat und ihr chemisches Verhalten werden diskutiert. Dabei stehen Di- und Oligomerisierungen einerseits und Diels-Alder-Reaktionen andererseits im Vordergrund. 16 und 17 sind sehr reaktive Dienophile; 17 ist daruber hinaus auch als Dien einzusetzen. The Symmetrical Cyclooctadienynes: 1,5-Cyclooctadien-3-yne and 1,3-Cyclooctadien-6-yne Starting with 1,5-cyclooctadiene (1) and cyclooctatetraene (2), respectively, the title compounds 16 and 17, hig…
The Reductive σ Bond Cleavage of Barbaralane and 2,6‐Diphenylbarbaralane
1987
Barbaralane (2) and 2,6-diphenylbarbaralane (8) are synthesized in a straightforward way. The reductive cleavage of the strained hydrocarbons is achieved with alkali metals. The structure of the metallation products, in particular the bonding in the resulting allyl moieties, is elucidated by 1H- and 13C-NMR spectroscopy. The chemical behavior (oxidation, protonation, alkylation) sheds light on the modes of stabilization of the alkali metal derivatives. Die reduktive σ-Bindungsspaltung von Barbaralan und 2,6-Diphenylbarbaralan Barbaralan (2) und 2,6-Diphenylbarbaralan (8) werden auf rationelle Weise synthetisiert und die gespannten Kohlenwasserstoffe durch Reaktion mit Alkalimetallen redukti…
Die unsymmetrischen Cyclooctadienine: 1,3‐Cyclooctadien‐5‐in und 1,6‐Cyclooctadien‐3‐in
1985
Verschiedene Varianten des synthetischen Zugangs zu den beiden Titelverbindungen 15 und 45 werden diskutiert. 15 und 45 konnen in situ umgesetzt werden. Fur die Isolierung in reiner Form ist ihre mittlere Lebensdauer zu gering. Sie isomerisieren sich auf der C8H8-Energiehyperflache zu Styrol (47) und/oder Benzocyclobuten (22).
Photochemie des 1,3‐Distyrylbenzols — Ein neuer Weg zu syn ‐[2.2](1,3)Cyclophanen
1986
New Insights into the Stoichiometric and Catalytic Reactivity of Unsaturated Pd 3 (dppm) 3 CO n + Clusters ( n = 0, 1) Towards Halocarbons – First Ev…
2005
The title clusters, Pd 3 (dppm) 3 (CO) + and Pd 3 (dppm) 3 (CO) 0 can be electrochemically generated from the 1- and 2-electron reductions, respectively, of the Pd 3 (dppm) 3 (CO) 2 + cluster [dppm = bis(diphenylphosphanyl)methane; Pd 3 2 + ]. Pd 3 + reacts in a stoichiometric ratio with methyl iodide, MeI, and benzyl bromide, BzBr, in THF to provide the corresponding Pd 3 (X) + adducts (X = I, Br respectively) as inorganic products. Other products are Bz 2 and PhMe for BzBr but, for MeI, no organic product was observed (since they are too volatile). In the presence of the same substrates, Pd 3 0 also reacts in a stoichiometric ratio to form the same organics and the Pd 3 -(X) + adducts (X …
Tuning the selectivity of light hydrocarbons in natural gas in a family of isoreticular MOFs
2017
Purification of methane from other light hydrocarbons in natural gas is a topic of intense research due to its fundamental importance in the utilization of natural gas fields. Porous materials have emerged as excellent alternative platforms to conventional cryogenic methodologies to perform this task in a cost- and energy-efficient manner. Here we report a new family of isoreticular chiral MOFs, prepared from oxamidato ligands derived from natural amino acids L-alanine, L-valine and L-leucine, where, by increasing the length of the alkyl residue of the amino acid, the charge density of the MOF's channels can be tuned (1 > 2 > 3), decreasing the adsorption preference towards methane over lig…