Search results for "IR absorption"

showing 2 items of 12 documents

Luminescence Efficiency of Si/SiO 2 Nanoparticles Produced by Laser Ablation

2019

Photoluminescence properties of Si(core)/SiO 2 (shell) nanoparticles produced by pulsed laser ablation in aqueous solution are investigated with the purpose to highlight the microscopic processes that govern the emission brightness and stability. Time resolved spectra evidence that these systems emit a µs decaying band centered around 1.95 eV, that is associated with the radiative recombination of quantum-confined excitons generated in the Si nanocrystalline core. Both the quantum efficiency and the stability of this emission are strongly dependent on the pH level of the solution, that is changed after the laser ablation is performed. They enhance in acid environment because of the H + pass…

PhotoluminescenceLaser ablationMaterials scienceSi/SiO2 nanoparticles pulsed laser ablation quantum confinement luminescence IR absorption pH dependencebusiness.industry2Surfaces and InterfacesCondensed Matter Physicslaser ablation; pH dependence; photoluminescence; quantum confinement; Si/SiO ; 2; nanoparticlesquantum confinementSurfaces Coatings and FilmsElectronic Optical and Magnetic MaterialsQuantum dotSio2 nanoparticleslaser ablationMaterials ChemistryPh dependenceOptoelectronicsphotoluminescencenanoparticlespH dependenceElectrical and Electronic EngineeringLuminescencebusinessSi/SiOphysica status solidi (a)
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Molecular spectra of liquors as method of studying delignification process

2011

FTIR-spectra of dried compounds of black liquors after aspen kraft cooks of different duration were obtained. Twelve samples corresponding to changing H-factor value in limits 4-1010 were investigated. The parameters of selected bands corresponding to lignin fragments vibrations were calculated using mathematical treatment methods. It was revealed that the positions and bandwidths of these lignin bands did not change. During cook at the first stage (H-factor values 4-200) their intensities strongly increased with different rates. During the next time period when the H-factor values were more than 200 a slow phase with small changes of the bands intensities were revealed. The IR-spectra of b…

pulpaspen woodIR absorption
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