Search results for "Zen"
showing 10 items of 3479 documents
Mechanismus der Umsetzung von 1,1-Diphenylhydrazin mit Azodicarbonsäure-diethylester
1979
Bei der Umsetzung von 1,1-Diphenylhydrazin (1a) mit Azodicarbonsaure-diethylester (2a) uber-lagern sich funf Reaktionsmechanismen: A und B) Oxidation des Diphenylhydrazins 1a durch den Azodicarbonsaureester 2a zum Aminonitren 8; Bildung des Tetrazens 10 entweder durch Dimerisierung von 8 oder uber das Tetrazan 11; Zerfall von 11 in N2 und Diphenylamin. — C) Addition des Aminonitrens 8 an den Azodicarbonsaureester 2a zum Aminoazimin 3a; Zerfall von 3a in das Urethan 4a und den Azidoameisensaureester 5a. — D) Isomerisierung des Aminoazimins 3a zu 13 und Reduktion von 13 durch 1a zum Tetrazen 14; Spaltung von 14 in Diphenylamin und das Azid 15; Zerfall von 15 in Ethylcyanat (17) und den Kohlen…
<title>Hologram recording in azobenzene oligomers</title>
2003
Elementary hologram (holographic grating) recording and their coherent optical erasure have been experimentally studied in azobenzene oligomer (ABO) layers differing by their chemical composition, matrices and by the connection type of azobenzene chromophores to the matrix (dispersed or covalently bound). The best holographic parameters (7.9% diffraction efficiency and 86 J/cm2 specific recording energy) were achieved in the samples with covalent bonding to the matrix. Vector recording is also possible. Recording is unstable and reversible. The coherent optical erasure studies have shown its efficiency dependencies on the initial diffraction efficiency, erasing beam intensity and grating pe…
Holographic recording of surface relief gratings in tolyle-based azobenzene oligomers
2008
Abstract Holographic recording of surface relief gratings (SRG) in tolyle-based azobenzene oligomer films have been carried out at 514.5 nm. It was experimentally studied by spectroscopic and AFM methods. The maximum surface modulation amplitude was 35 nm. SRG formation is explained by the mean-field model and by the photodegradation of chromophores enabling the directional mass transport as the result of trans–cis transformations. The conclusion is made that SRG are stable but the diffraction efficiency (DE) changes are due to the complementary decaying amplitude-phase gratings. Strong polarization dependences of transmitted and reflected DE are found. They are explained by the diffraction…
Predictive Power of the Emissivity Angular Variation of Soils in the Thermal Infrared (8–14 <inline-formula> <tex-math notation="LaTeX">$…
2018
A confident knowledge of land surface emissivity at viewing zenith angles far from nadir is of prime interest to perform an accurate correction of the anisotropy effect in the measurements made by orbiting thermal infrared (TIR) sensors. It is also important for the correct treatment of angular measurements carried out by remote sensors such as AATSR/ENVISAT, MODIS/Terra–Aqua, or the recently launched SLSTR/Sentinel-3, which can also be used for the angular normalization of land surface temperature due to viewing geometry effect. In this letter, the anisotropy of TIR emissivity predicted by two analytical, Warren–Wiscombe–Dozier and Hapke, models based on Mie diffraction theory was compared…
A Mononuclear Uranium(IV) Single-Molecule Magnet with an Azobenzene Radical Ligand
2015
A tetravalent uranium compound with a radical azobenzene ligand, namely, [{(SiMe2NPh)3‐tacn}UIV(η2‐N2Ph2.)] (2), was obtained by one‐electron reduction of azobenzene by the trivalent uranium compound [UIII{(SiMe2NPh)3‐tacn}] (1). Compound 2 was characterized by single‐crystal X‐ray diffraction and 1H NMR, IR, and UV/Vis/NIR spectroscopy. The magnetic properties of 2 and precursor 1 were studied by static magnetization and ac susceptibility measurements, which for the former revealed single‐molecule magnet behaviour for the first time in a mononuclear UIV compound, whereas trivalent uranium compound 1 does not exhibit slow relaxation of the magnetization at low temperatures. A first approxim…
Extending in vitro digestion models to specific human populations: Perspectives, practical tools and bio-relevant information
2017
29th International Conference of the European-Federation-of-Food-Science-and-Technology (EFFoST) -- NOV 10-12, 2015 -- Athens, GREECE
Digital Citizenship: A Survey On Teachers' Perception And Teaching Practices
2021
Nowadays citizens live in communities made up of complex interweaving of physical reality, technologies, digital media and social networks and are faced with a completely new set of challenges and opportunities that require a critical and cultured citizenship, capable of dealing with differences in a way responsible and humane. Digital citizenship is defined as the acceptable, ethical, and responsible use of technology that emphasizes a more collaborative, creative, and self-empowering use of technology in education as well as in personal use. Teachers are essential in helping students develop digital citizenship skills as they model and teach digital citizenship in their classrooms. Teache…
CCDC 255649: Experimental Crystal Structure Determination
2005
Related Article: T.S.B.Baul, W.Rynjah, E.Rivarola, C.Pettinari, A.Linden|2005|J.Organomet.Chem.|690|1413|doi:10.1016/j.jorganchem.2004.12.013
Le hasard dans le droit de l'Union européenne en matière d'accès au territoire de l'Union
2019
The article explores the question of "chance" in the European Union Law in the field of the admission of third States citizens and asylum seekers to the territory of the European Union. Le hasard fait son apparition dans le droit de l'Union européenne en matière de d'accès au territoire de l'Union pour les ressortissants des pays tiers, meme pour les demandeurs d'asile ou pour les personnes en besoin de protection. Dans ce contexte, le hasard perd les caractères habituels qui lui sont reconnus par les Etats membres de l'Union pour devenir un instrument de dissuasion au service de la priorité politique de reduire les mouvements migratoires.
Hybrid Engagement: Discourses and Scenarios of Entrepreneurial Journalism
2018
Although the challenge posed by social media and the participatory turn concerns culture and values at the very heart of journalism, journalists have been reluctant to adopt participatory values and practices. To encourage audience participation and to offer journalism that is both trustworthy and engaging, journalists of the future may embrace a hybrid practice of journalistic objectivity and audience-centred dialogue. As innovative and experimental actors, entrepreneurial journalism outlets can perform as forerunners of such a culture. By analysing discourses in the “About Us” pages of 41 entrepreneurial journalism outlets, the article examines the emerging journalistic ethos of entrepren…