Search results for "metalls"
showing 10 items of 12 documents
Comercio protohistórico: el registro del Nordeste peninsular y la circulación de mineral de plomo en Ibiza y el Bajo Priorato (Tarragona)
2012
[ES] Los estudios que hemos venido realizando indican que el plomo de la cuenca minera del Bajo Priorato (Tarragona) circula en el ámbito fenicio-tartesio. Sin embargo, los análisis realizados sobre un conjunto de muestras minerales y metálicas de la isla de Ibiza ponen de manifiesto la explotación de la galena argentífera local, cuyo uso coexiste en el yacimiento de sa Caleta con el mineral de Cartagena; no se documenta, en cambio, plomo de procedencia prioratina. Si sumamos a ello los datos relativos a las evidencias que aportan los registros cerámicos ibicencos y catalanes de los ss. VII a VI a.n.e., se va trazando un panorama que pone en evidencia la existencia de una pluralidad de rede…
WS2/MoS2 Heterostructures through Thermal Treatment of MoS2 Layers Electrostatically Functionalized with W3S4 Molecular Clusters
2020
The preparation of 2D stacked layers that combine flakes of different nature, gives rise to countless number of heterostructures where new band alignments, defined at the interfaces, control the electronic properties of the system. Among the large family of 2D/2D heterostructures, the one formed by the combination of the most common semiconducting transition metal dichalcogenides WS2/MoS2, has awaken great interest due to its photovoltaic and photoelectrochemical properties. Solution as well as dry physical methods have been developed to optimize the synthesis of these heterostructures. Here a suspension of negatively charged MoS2 flakes is mixed with a methanolic solution of a cationic W3S…
Pirotechnia / del S. Vannucio Biringuccio ... ; nella quale si tratta non solo della diuersità delle minere, ma ancho di quanto si ricerca alla prat…
1559
Sign.: a-z8, aa-xx8 Gravats al llarg del text. - Capll. i altra orn. Postil·les
Heterometallic palladium-iron metal-organic framework as a highly active catalyst for cross-coupling reactions.
2022
Palladium-based metal-organic frameworks (Pd-MOFs) are an emerging class of heterogeneous catalysts extremely challenging to achieve due to the facile leaching of palladium and its tendency to be reduced. Herein, Pd(II) was successfully incorporated in the framework of a MOF denoted as MUV-22 using a solvent assisted reaction. This stable MOF, with square-octahedron (soc) topology as MIL-127, and a porosity of 710 m2 g−1, is highly active, selective, and recyclable for the Suzuki-Miyaura allylation of aryl and alkyl boronates as exemplified with the coupling between cinnamyl bromide and Me-Bpin, a typically reluctant reagent in cross-coupling reactions.
Georgii Agricolae De ortu & causis subterraneorum Lib. V ; De natura eirum quae efluunt ex terra Lib. IIII ; De natura fossilium Lib. X ; De ueteribu…
1558
Sign.: a4, A-Z6, 2A-2O6, 2P8, 2Q-2S6, 2T8 Caplletres
Chromium Exposure and Risk of Cardiovascular Disease in High Cardiovascular Risk Subjects ― Nested Case-Control Study in the Prevention With Mediterr…
2017
BACKGROUND: Epidemiological data on chromium (Cr) exposure and the risk of cardiovascular disease (CVD) are still limited. Toenail Cr level (TCL) provides a time-integrated measure reflecting long-term Cr exposure. We measured TCL to assess the hypothesis that long-term Cr exposure was inversely associated with incident CVD in a population at high risk for CVD.Methods and Results:The associations between TCL and CVD were evaluated in a case-control study nested within the "PREvención con DIeta MEDiterránea" (PREDIMED) trial. We randomly selected 147 of the 288 patients diagnosed with CVD during follow-up and matched them on age and sex to 271 controls. Instrumental neutron activation analys…
Metal-Organic Frameworks as Chemical Nanoreactors: Synthesis and Stabilization of Catalytically Active Metal Species in Confined Spaces
2020
ConspectusSince the advent of the first metal-organic frameworks (MOFs), we have witnessed an explosion of captivating architectures with exciting physicochemical properties and applications in a wide range of fields. This, in part, can be understood under the light of their rich host-guest chemistry and the possibility to use single-crystal X-ray diffraction (SC-XRD) as a basic characterization tool. Moreover, chemistry on preformed MOFs, applying recent developments in template-directed synthesis and postsynthetic methodologies (PSMs), has shown to be a powerful synthetic tool to (i) tailor MOFs channels of known topology via single-crystal to single-crystal (SC-SC) processes, (ii) impart…
Fast Polymeric Functionalization Approach for the Covalent Coating of MoS2 Layers
2021
We present the covalent coating of chemically exfoliated molybdenum disulfide (MoS2) based on the polymerization of functional acryl molecules. The method relies on the efficient diazonium anchoring reaction to provoke the in situ radical polymerization and covalent adhesion of functional coatings. In particular, we successfully implement hydrophobicity on the exfoliated MoS2 in a direct, fast, and quantitative synthetic approach. The covalent functionalization is proved by multiple techniques including X-ray photoelectron spectroscopy and TGA-MS. This approach represents a simple and general protocol to reach dense and homogeneous functional coatings on 2D materials.
Pirotechnia
1559
Sign.: a-z8, aa-xx8 Marca d'imp. en port Postil·les Gravats al llarg del text. - Capll. i altra orn
Path to Overcome Material and Fundamental Obstacles in Spin Valves Based on MoS2 and Other Transition-Metal Dichalcogenides
2019
Experimental studies on spin valves with exfoliated 2D materials face the main technological issue of ferromagnetic electrode oxidation during the 2Ds integration process. As a twofold outcome, magnetoresistance (MR) signals are very difficult to obtain and, when they finally are, they are often far from expectations. We propose a fabrication method to circumvent this key issue for 2D-based spintronics devices. We report on the fabrication of NiFe/MoS2/Co spin valves with mechanically exfoliated multilayer MoS2 using an in situ fabrication protocol that allows high-quality nonoxidized interfaces to be maintained between the ferromagnetic electrodes and the 2D layer. Devices display a large …