1,465 research outputs found
"Chacun écrit pour soi", film de Felix von Boehm et Dominik Graf, 2023, durée 2hrs47, diffusion Arte, script, voix off, sous-titrage
No full textJ"eder schreibt für sich allein. Schrifsteller im Nationalsozialismus" Film von Felix von Boehm und Dominik Graf 202
"Chacun écrit pour soi", film de Felix von Boehm et Dominik Graf, 2023, durée 2hrs47, diffusion Arte, script, voix off, sous-titrage
No full textJ"eder schreibt für sich allein. Schrifsteller im Nationalsozialismus" Film von Felix von Boehm und Dominik Graf 202
In Search of the Author of Chronica Polonorum Ascribed to Gallus Anonymus: A Stylometric Reconnaissance
No full textThe article deals with the question of authorship of the thirteenth-century Chronica Polonorum (or Gesta principium Polonorum [The Deeds of the Princes of the Poles]), also known as The Polish Chronicle. It seeks to verify the hypothesis, recently reproposed by Tomasz Jasiński, whereby the author was of Venetian origin. The hypothesis is namely based on the textual similarities observed between Translatio Sancti Nicolai by an author referred to as the ‘Monk of Lido’ (Monachus Littorensis) and the Chronica. The attribution attempt put forth by M. Eder is based upon stylometric methods that measure the frequencies of the most frequent words in the texts under research (mainly, conjunctions, prepositions, pronouns, and particles) which are subsequently subjected to cluster analysis, multidimensional scaling, or principal components analysis. The outcome of the experiment in question has demonstrated a strong resemblance between the Translatio Sancti Nicolai and the Polish Chronicle, which may be regarded as an substantial argument in support of the Venetian background hypothesis
Elucidation of a Core–Shell Structure in Phenyl-Grafted Carbon Nitride/TiO2 Nanohybrids for Visible-Light-Mediated H2 Production with Simultaneous Rhodamine B Degradation
No full textDual-functional photocatalysts help to maximize
resource utilization in water remediation, but often they are visiblelight-
inactive, toxic, and cost-intensive. Herein, a type-II heterojunction
visible-light-active photocatalyst is reported for tandem
degradation of Rhodamine B and generation of H2. A Rhodamine B
degradation rate of 2.3 × 10−2 min−1 and H2 production activity of
5789 μmol h−1 g−1 are shown. The hybrid shows a gradient core−
shell morphology with a visible - light-absorbing phenyl-modified
carbon nitride (PhCN) core and a porous PhCN/TiO2 outer shell,
resulting in an enhanced interaction between the catalyst and the
surroundings. The nanoscale crystallization of TiO2 on PhCN’s
surface, shifts the triazine network structure, while autoclave
treatments further increase the band gap and suppress charge
carrier recombination. The influence of nanoscale morphological changes on photocatalytic activity was examined by varying the
component ratios and thermal treatments, highlighting the strong correlation between the nanoscale architecture and the enhanced catalytic activity. This work provides a detailed guide to the exploration of environmentally friendly dual-functional photocatalysts
Oxygen vacancies and interfaces enhancing photocatalytic hydrogen production in mesoporous CNT/TiO2 hybrids
No full textWe demonstrate a unique route towards hierarchical assemblies of mesoporous TiO2 and CNT/TiO2 photocatalysts by a combination of electrospinning and sol–gel methods. The resulting materials exhibit a mesoporous network of highly crystalline, well-connected inorganic nanocrystals with an order of magnitude higher photocatalytic activity than individualised TiO2 nanoparticles. The in-situ combination of small amounts of MWCNTs with TiO2 to form an electrospun CNT/TiO2 hybrid further enhanced the oxide photoactivity considerably, reaching hydrogen evolution rates of 1218 μmol/h in water splitting in the presence of sacrificial reagents under UV irradiation. We also discuss the effect of oxygen vacancies on the oxide crystallisation and phase transformation. These vacancies lead to inter-bandgap states and a lower flat band potential that facilitates the photocatalytic process
The effect of ligand removal in UiO-66 on the photocatalytic CO₂ reduction performance studied by operando DRIFTS
No full textIce Nucleation Activity of Graphene and Graphene Oxides
No full textAerosols
can act as cloud condensation nuclei and/or ice-nucleating
particles (INPs), influencing cloud properties. In particular, INPs
show a variety of different and complex mechanisms when interacting
with water during the freezing process. To gain a fundamental understanding
of the heterogeneous freezing mechanisms, studies with proxies for
atmospheric INPs must be performed. Graphene and its derivatives offer
suitable model systems for soot particles, which are ubiquitous aerosols
in the atmosphere. In this work, we present an investigation of the
ice nucleation activity (INA) of different types of graphene and graphene
oxides. Immersion droplet freezing experiments as well as additional
analytical analyses, such as X-ray photoelectron spectroscopy, Raman
spectroscopy, and transmission electron microscopy, were performed.
We show within a group of samples that a highly ordered graphene lattice
(Raman G band intensity >50%) can support ice nucleation more effectively
than a lowly ordered graphene lattice (Raman G band intensity <20%).
Ammonia-functionalized graphene revealed the highest INA of all samples.
Atmospheric ammonia is known to play a primary role in the formation
of secondary particulate matter, forming ammonium-containing aerosols.
The influence of functionalization on interactions between the particle
interface and water molecules, as well as on hydrophobicity and agglomeration
processes, is discussed
Khoo Kay Kim, professor of Malaysian history : a biobibliometric study
No full textPresents an analysis of the publication productivity, authorship pattern, channels of communication, journal preference and language preference of Professor Dato' Khoo Kay Kim, Professor of Malaysian History in the University of Malaya, Kuala Lumpur. The results of this biobibliometric study indicate that he can be a role model for future Malaysian historians to emulate his various achievements especially in the field of history education
Bottom-up Synthese von Kohlenstoffallotropen
No full textKohlenstoff steht in seiner Vielseitigkeit unübertroffen da und ist damit wohl das facettenreichste Element im Universum. Seine inhärente Fähigkeit, verschiedene Hybridisierungszustände anzunehmen, ebnet den Weg für eine Vielzahl von Strukturen, Materialien und Molekülen, jeweils mit einem einzigartigen Eigenschaftsprofil. Kohlenstoffallotrope verkörpern diese Vielfalt, da sie ausschließlich aus Kohlenstoffatomen bestehen. Während Graphit und Diamant, die beiden natürlich vorkommenden Formen des elementaren Kohlenstoffs, Mitglieder dieser Kategorie sind, hat die vergangenen 35 Jahre eine Renaissance in unserem Verständnis und der Anwendung von kohlenstoffbasierten Materialien erlebt. Diese Periode war geprägt von bahnbrechenden Fortschritten in den Materialwissenschaften, der Chemie und der Physik, vor allem durch die Entdeckung und Erforschung neuer Kohlenstoffallotrope: der 0D-Buckybälle, 1D-Kohlenstoffnanoröhren und 2D-Einzel- und Mehrschichtgraphen.Trotz enormen Interesses an kohlenstoffhaltigen Materialien gab es bisher keine Durchbrüche in der Kategorie der 3D-Allotrope. Diese Arbeit stellt einen Ausgangspunkt dar, um die Lücke in den Kohlenstoffnetzwerken zu schließen und zielt auf die Synthese der theoretischen 3D-Kohlenstoffallotrope, speziell 6.82 D und 6.82 P Polybenzol, ab. Diese nanoporösen Kohlenstoffstrukturen, mit ihren einzigartigen elektronischen Eigenschaften und der Fähigkeit, verschiedene Verbindungen einzuschließen, versprechen Anwendungen in der Wasserstoffspeicherung, der Spintronik und der Batterietechnologie. Ein neuartiger Bottom-up-Syntheseansatz wurde eingeführt, der einen Monomer mit 8-gliedrigen Ringen nutzt und Aldol-Trimerisierung zur Bildung der 6-gliedrigen Ringe einsetzt. Während das ehrgeizige Ziel der Realisierung einer der Polybenzol-Modifikationen nicht erreicht wurde, hat diese Forschung erfolgreich zwei unterschiedliche und skalierbare synthetische Routen etabliert, die jeweils zu potenziellen Monomeren führen. Die Studie untersuchte auch intensiv die Rollen sowohl von Lewis- als auch von Brønsted-Säuren in Polymerisationsreaktionen und betonte den entscheidenden Einfluss von Reaktionstemperaturen und Lösungsmitteln auf die Ergebnisse. Die Charakterisierung der synthetisierten Proben mittels FT-IR-Spektroskopie zeigte bemerkenswerte Unterschiede zum Monomer, mit reduzierten Carbonyl- und Alkyl-Schwingungen. Beugungsstudien identifizierten die meisten Proben als amorph, einige zeigten jedoch Anzeichen von Strukturen mit langreichweitiger Ordnung. Interessanterweise deuteten Reaktionen mit spezifischen Säuren, wie CSA, PPTS und NbCl5, auf die potenzielle Bildung einer konsistenten supramolekularen Struktur hin. Obwohl der Weg zu einem neuartigen 3D-Kohlenstoffallotrop noch lang ist, signalisieren die Fortschritte in dieser Forschung eine vielversprechende Richtung in diesem anspruchsvollen Bereich.Carbon stands unparalleled in its versatility, arguably making it the most multifaceted element in the universe. Its inherent ability to adopt various hybridization states paves the way for a plethora of structures, materials, and molecules, each with its unique set of properties. Carbon allotropes epitomize this diversity, being compounds composed solely of carbon atoms. While graphite and diamond, the two naturally occurring forms of elemental carbon, are members of this category, the past 35 years have witnessed a renaissance in our understanding and application of carbon-based materials. This period has been marked by groundbreaking strides in materials science, chemistry, and physics, largely propelled by the discovery and exploration of novel carbon allotropes: the 0D buckyballs, 1D carbon nanotubes, and 2D single and multilayer graphene.Despite tremendous interest in carbonous materials, there has not been any disruption in the category of 3D allotropes. This work represents a starting point in closing the gap of carbon networks, targeting the synthesis of theoretical 3D carbon allotropes specifically 6.82 D and 6.82 P polybenzene. These nano-porous carbon structures, with their unique electronic attributes and ability to encapsulate various compounds, hold promise for applications in hydrogen storage, spintronics, and battery technology. A novel bottom-up synthesis approach was introduced, leveraging a monomer characterized by 8-membered rings and employing aldol trimerization to form the 6-membered rings.While the ambitious goal of realizing either polybenzene modification remained elusive, this research successfully established two distinct and scalable synthetic routes, each leading to potential monomers. The study also delved deep into the roles of both Lewis and Brønsted acids in polymerization reactions, highlighting the crucial influence of reaction temperatures and solvents on outcomes.Characterization of the synthesized samples via FT-IR spectroscopy revealed notable differences from the monomer, with reduced carbonyl and alkyl vibrations. Diffraction studies mostly identified the samples as amorphous, but a few exhibited hints of structures with long-range order. Interestingly, reactions involving specific acids, such as CSA, PPTS, and NbCl5, indicated the potential formation of a consistent supramolecular structure. While the journey toward a novel 3D carbon allotrope is still underway, the advancements made in this research signify a promising direction in this challenging domain
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