نتایج جستجو برای: silv
تعداد نتایج: 891 فیلتر نتایج به سال:
Free 4-undecenoxyphthalocyanine molecules were covalently bonded to Si(100) and porous silicon through thermic hydrosilylation of the terminal double bonds of the undecenyl chains. The success of the anchoring strategy on both surfaces was demonstrated by the combination of X-ray photoelectron spectroscopy with control experiments performed adopting the commercially available 2,3,9,10,16,17,23,...
Laser radiation-induced decomposition of gaseous organic selenides and tellurides resulting in chemical deposition of nanostructured materials on cold surfaces is reviewed with regard to the mechanism of the gas-phase decomposition and properties of the deposited materials. The laser photolysis and laser thermolysis of the Se and Te precursors leading to chalcogen deposition can also serve as a...
The structure of core-shell Cu@silica and Ag@Si nanoparticles obtained in one-step through evaporation of elemental precursors by a high-powered electron beam are investigated. The structure of the core and shell of the particles are investigated in order to elucidate their mechanisms of formation and factors affecting the synthesis. It is proposed that the formation of Cu@silica particles is m...
On the way to integrate lattice mismatched semiconductors on Si(001), the Ge/Si heterosystem was used as a case study for the concept of compliant substrate effects that offer the vision to be able to integrate defect-free alternative semiconductor structures on Si. Ge nanoclusters were selectively grown by chemical vapour deposition on Si nano-islands on silicon-on-insulator (SOI) substrates. ...
Si-NMR, gas adsorption and SAXS results are discussed to determine if the geometry and the electronic properties of Si sites, present in the MCM-41walls, are more similar to threethan to four-fold coordinated sites. The features of Si-MCM-41, SBA-15, Y zeolite and silica (SiO2), characterized by several techniques, are compared. It is shown that the pre-polymer geometries are similar to those o...
Continents ride high above the ocean floor because they are underlain by thick, low-density, Si-rich, and Mg-poor crust. However, the parental magmas of continents were basaltic, which means they must have lost Mg relative to Si during their maturation into continents. Igneous differentiation followed by lower crustal delamination and chemical weathering followed by subduction recycling are pos...
The risk of suicide behaviors in immigrant adolescents varies across countries and remains partly understood. We conducted a study in France to examine immigrant adolescents' likelihood of experiencing suicide ideation in the last 12 months (SI) and lifetime suicide attempts (SA) compared with their native counterparts, and the contribution of socioeconomic factors and school, behavior, and hea...
The first silenolates with exocyclic structures [(Me3Si)2Si(Si2Me4)2SiC(R)O]-K+ (2a: R = 1-adamantyl; 2b: mesityl; 2c: o-tolyl) were synthesized by the reaction of the corresponding acylcyclohexasilanes 1a-c with KOtBu. NMR spectroscopy and single-crystal X-ray diffraction analysis suggest that the aryl-substituted silenolates 2b,c exhibit increased character of functionalized silenes as compar...
Like siloles, benzosiloles have low lying LUMOs due to σ*-π* conjugation between Si and the butadiene moiety but are more amenable for structural tuning. In total, 27 benzosiloles, 12 of them already synthesized and another 15 newly reported here, have been investigated using DFT and TDDFT calculations with an aim to check their suitability for optoelectronic applications. Our results show that...
A series of pot experiments were conducted to: (1) evaluate the effects of different Si sources (soil- and foliar-applied) on grain yield and Si accumulation of rice supplied with varying P rates, and (2) evaluate Si absorption of rice using foliar- and soil-applied Si fertilizers. Three P rates, (0, 112, and 224 kg ha-1) combined with five Si treatments (wollastonite and slag applied at 4.5 to...
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