Search results for "Mines"
showing 10 items of 2609 documents
Reaction of polyamines with diethyloxalate: a convenient route for the synthesis of tetraazacycloalkanes
2006
International audience; The reactivity of various polyamines with diethyloxalate has been investigated. It appears that, in similar experimental conditions, primary diamines give predominantly [2+2] adducts while the use of secondary benzylated polyamines results in [1+1] condensation. Although the intermediate tetraamides formed in the first case are extremely poorly soluble and show very slow reactivity towards reducing agents, cyclam has been obtained by using ultrasounds during the reaction of the corresponding tetraoxomacrocycle with BH 3 /THF. The [1+1] cyclization reaction of diversely N-benzylated linear tetraamines, whose selective syntheses have been devised herein, gives access t…
Understanding the White-Emitting CaMoO4 Co-Doped Eu3+, Tb3+, and Tm3+ Phosphor through Experiment and Computation
2019
In this article, the synthesis by means of the spray pyrolysis method, of the CaMoO4 and rare-earth cation (RE3+)-doped CaMoO4:xRE3+ (RE3+ = Eu3+, Tb3+, and Tm3+; and x = 1, 2, and 4% mol) compounds, is presented. The as-synthesized samples were characterized using X-ray diffraction, Rietveld refinement, field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and photoluminescence (PL) spectroscopy. To complement and rationalize the experimental results, first-principles calculations, at the density functional theory level, have been performed to analyze the band structure and density of states. In addition, a theoretical method based on the calculations of surface energie…
The variation of the law applicable to the family property regime in EU regulations n. 2016/1103 and 1104
2021
The essay examines the discipline of EU regulations n. 2016/1103 and 1104 concerning the identification of the law applicable to the family property regime. Specifically, the work reflects on problems arising after a change, during the relationship, of the substantial law applicable to the couple?s property regime.
Formation of Si/SiO2 Luminescent Quantum Dots From Mesoporous Silicon by Sodium Tetraborate/Citric Acid Oxidation Treatment
2019
We propose a rapid, one-pot method to generate photoluminescent (PL) mesoporous silicon nanoparticles (PSiNPs). Typically, mesoporous silicon (meso-PSi) films, obtained by electrochemical etching of monocrystalline silicon substrates, do not display strong PL because the silicon nanocrystals (nc-Si) in the skeleton are generally too large to display quantum confinement effects. Here we describe an improved approach to form photoluminescent PSiNPs from meso-PSi by partial oxidation in aqueous sodium borate (borax) solutions. The borax solution acts to simultaneously oxidize the nc-Si surface and to partially dissolve the oxide product. This results in reduction of the size of the nc-Si core …
Pressure-Dependent Tuning of Photoluminescence and Size Distribution of Carbon Nanodots for Theranostic Anticancer Applications
2020
Carbon nanodots (CDs) have recently attracted attention in the field of nanomedicine because of the biocompatibility, cost-effective nature, high specific surface, good near infrared (NIR) photothermal conversion into heat and tunable fluorescence properties, which have paved the way toward incorporating use of CDs into innovative anticancer theranostic platforms. However, a reliable synthesis of CDs with established and controlled physiochemical proprieties is precluded owing to the lack of full manipulation of thermodynamic parameters during the synthesis, thus limiting their use in real world medical applications. Herein, we developed a robust solvothermal protocol which allow fine contr…
Effect of thermal annealing on the luminescence of defective ZnO nanoparticles synthesized by pulsed laser ablation in water
2016
This work concerns ZnO nanoparticles (NPs), with sizes of tens of nm, produced by ablation with a pulsed Nd:YAG laser of a Zn plate in H2O. TEM images evidence the formation of nanoparticles with sizes of tens of nm. Moreover, HRTEM images and Raman spectra show that the distance between the crystalline planes and the vibrational modes are consistent with ZnO nanocrystal in wurtzite structure. Their optical properties are characterized by two emission bands both excited above the energy gap (3.4 eV): the first at 3.3 eV is associated with excitons recombination, the second at 2.2 eV is proposed to originate from a singly ionized oxygen vacancy. The green emission is independent of water pH,…
Thermoluminescence response of sodalime glass irradiated with photon and electron beams in the 1-20 Gy range
2011
Abstract The thermoluminescence response of a watch commercial glass was studied after irradiation with photons and electrons, in the range 1–20 Gy, of interest in accidental dosimetry; a linear response was obtained with both beams. This result, together with the satisfactory time stability of the thermoluminescence signal, indicates this glass as a potential material for retrospective dosimetry applications.
Gold Au(I)6 Clusters with Ligand-Derived Atomic Steric Locking: Multifunctional Optoelectrical Properties and Quantum Coherence
2023
Funding Information: This work was supported by the ERC Advanced grant (DRIVEN, ERC‐2016‐AdG‐742829), the ERC grant (834742), the EU H2020‐MSCA‐RISE‐872049 (IPN‐Bio), the Academy of Finland's Centre of Excellence in Molecular Engineering of Biosynthetic Hybrid Materials Research (HYBER, 2014–2019), and Life‐Inspired Hybrid Materials (LIBER, 346108), Academy of Finland project fundings (No. 352900, 314810, 333982, 336144, 352780, 352930 and 353364), FinnCERES and Photonics Research and Innovation (PREIN) flagship programs. The authors acknowledge the provision of facilities and technical support by Aalto University OtaNano – Nanomicroscopy Center (Aalto‐NMC). | openaire: EC/H2020/834742/EU//…
Luminescent Silicon nanocrystals produced by ns pulsed laser ablation
2013
The reduction of Si down to nanoscale introduces a peculiar visible luminescence, surprisingly for a not highly emissive material. This feature is relevant in connection with several application fields (optoelectronics, medicine) and has lead the research towards the development of production methods successful to control the physical and chemical properties of the nanosized Si so as to enhance and tune the luminescence. To this purpose, the laser ablation in liquids is particularly promising since it provides effective controlling parameters (laser photon energy, fluence, repetition rate, liquid reactivity) for the morphology and the structure of Si-related products. Here we report a study…
Acid–base properties of functionalised tripodal polyamines and their interaction with nucleotides and nucleic acids
2010
Novel, highly positively charged tripodal polyamines with appended heterocyclic moieties revealed an intriguing panel of protonation species within the biologically relevant range. Studied compounds bind nucleotide monophosphates by mostly electrostatic interactions but only the imidazole analogue showed selectivity toward UMP in respect to other nucleotides. Strong binding of all the studied compounds to both ds-DNA and ds-RNA is to some extent selective toward the latter, showing rather rare RNA over DNA preference.