Search results for "METAL"

Density-Functional Tight-Binding Simulations of Curvature-Controlled Layer Decoupling and Band-Gap Tuning in Bilayer MoS2

2014

Monolayer transition-metal dichalcogenides (TMDCs) display valley-selective circular dichroism due to the presence of time-reversal symmetry and the absence of inversion symmetry, making them promising candidates for valleytronics. In contrast, in bilayer TMDCs both symmetries are present and these desirable valley-selective properties are lost. Here, by using density-functional tight-binding electronic structure simulations and revised periodic boundary conditions, we show that bending of bilayer MoS2 sheets breaks band degeneracies and localizes states on separate layers due to bendinginduced strain gradients across the sheets. We propose a strategy for employing bending deformations in b…

Investigation of the aqueous transmetalation of pi-allylpalladium with indium: some theoretical and experimental evidence about the nature of allylin…

2005

In this paper we report some theoretical and experimental evidence concerning the nature of the allyl-In intermediate generated by umpolung of allyl-Pd complexes in the Pd(OAc)(2)/TPPTS catalysed allylation reaction of benzaldehyde. The allylic substrate reacts at the substituted terminus, because of the formation of an equilibrating mixture of eta(1)-allyl-In(I) specie with the gamma-substituted regioisomer being more reactive.

Monitoring Volcanic Eruptions Using Trace Metals In Tree-Rings: Preliminary Results From Mt. Etna

2010

8. Active volcanoes can influence surrounding vegetation both through passive degassing during quiescent periods and through eruptive degassing, by introducing into the atmosphere several metals as gases and particles. The chemical composition of tree-rings has been generally used to investigate the effects of anthropogenic gas emissions and dendrochemical methods have successfully recorded variations in the pollution levels. The use of tree-rings analysis in active volcanic areas has shown that vascular plants could be used as archives of volcanogenic metals deposition. Tree cores of Pinus Nigra and Populus tremula were collected in sites located both on the downwind (Citelli and Mt. Fonta…

Dioxomolybdenum(VI) and -Tungsten(VI) Amino Bisphenolates as Epoxidation Catalysts

2016

Low-cost metallate salts Na2MO4·2H2O (M = molybdenum, tungsten) react with a tridentate amine bisphenol bis(2-hydroxy-3-tert-butyl-5-methylbenzyl)methylamine (H2ONOtBu) under ambient conditions in acidic methanol solutions. The reactions lead to the formation of isostructural dioxo complexes [MO2(ONOtBu)(MeOH)]·MeOH in convenient yields. Spectral data as well as X-ray analyses reveal these complexes to be isostructural. Both compounds were tested as catalysts for epoxidation of olefins using cis-cyclooctene, cyclohexene, norbornene and styrene as substrates and tert-butyl hydroperoxide and hydrogen peroxide as oxidants. The molybdenum complex catalyses selectively the oxidation of cis-cyclo…

Cleavage of Ge–Ge and Sn–Sn Triple Bonds in Heavy Group 14 Element Alkyne Analogues (EAriPr4)2 (E = Ge, Sn; AriPr4 = C6H3-2,6(C6H3-2,6-iPr2)2) by Rea…

2016

The reactions of heavier group 14 element alkyne analogues (EAriPr4)2 (E = Ge, Sn; AriPr4 = C6H3-2,6-(C6H3-2,6-iPr2)2) with the group 6 transition-metal carbonyls M(CO)6 (M = Cr, Mo, W) under UV irradiation resulted in the cleavage of the E–E triple bond and the formation of the complexes {AriPr4EM(CO)4}2 (1–6), which were characterized by single crystal X-ray diffraction as well as by IR and multinuclear NMR spectroscopy. Single-crystal X-ray structural analyses of 1–6 showed that the complexes have a nearly planar rhomboid M2E2 core with three-coordinate group 14 atoms. The coordination geometry at the group 6 metals is distorted octahedral formed by four carbonyl groups as well as two br…

Rajoitettu vai rajaton valta? : Sorsakosken hienotaetehtaan isännöitsijöiden suhtautuminen ja vuorovaikutus työväestöönsä vuosina 1891 - 1938

2011

Low back disorders in the long term among employees in the engineering industry : a study with 5-, 10- and 28-year follow-ups

2010

Nanofilm Low Cost Oxygen Sensors

2009

Abstract The resitivity change of ultra thin metals under air exposure is used for vacuum or inert gas packaging control. In order to reach low cost, single use applications, few nm thin Aluminum layers were deposited on PET substrates and combined with wireless electronic readout circuitry. The sensor respose is characterized by resistance changes and explained in terms of multiphase diffusion mechanisms which are very sensitive to technological parameters.

Multimetallic Oxynitrides Nanoparticles for a New Generation of Photocatalysts

2019

A versatile synthetic strategy for the preparation of multimetallic oxynitrides has been designed and here exemplarily discussed considering the preparation of nanoscaled zinc-gallium oxynitrides and zinc-gallium-indium oxynitrides, two important photocatalysts of new generation, which proved to be active in key energy related processes from pollutant decomposition to overall water splitting. The synthesis presented here allows the preparation of small nanoparticles (less than 20 nm in average diameter), well-defined in size and shape, yet highly crystalline and with the highest surface area reported so far (up to 80 m2  g-1 ). X-ray diffraction studies show that the final material is not a…

Interaction between surface plasmon polaritons and molecules in strong coupling limit

2016

Miniaturization of optical elements and their integration to electronic circuits is limited by diffraction limit. It was realized that light being coupled to surface plasmons (SP) can overcome this limit. Employing also optically active molecules in combination with SPs can drive optical circuits to nm-scale and add functionalities. For efficient performance of plasmonic elements involving fluorescent dye molecules investigation of physics behind their interaction is of high priority. In this thesis interaction between surface plasmon polaritons (SPPs) and different dye molecules has been studied, especially within strong coupling limit, which brings in totally new physical properties in th…