Search results for "Visible spectrum"

showing 10 items of 155 documents

Visible light apparatus for preliminary tests of x-ray optics

2006

We report a useful visible light testing procedure for a first analysis of soft X-ray grazing incidence optics (0.1-2 keV). Although diffraction is a limit in the application of this method, great advantages are obtained by running the tests in air with direct access to modify the geometrical mounting of the individual mirror shells. We present the experimental apparatus and show the first results of the investigation of light weight optics based on plastic foil material and comparison with results obtained with an X-ray beam.

DiffractionPhysicsbusiness.industryNear-field opticsX-ray opticsLaserlaw.inventionOpticslawOptoelectronicsBeam expandergrazing incident optics laser beam expander soft x-ray test in visible lightbusinessFOIL methodBeam (structure)Visible spectrumSPIE Proceedings
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Visible-light photoelectrodegradation of diuron on WO3 nanostructures

2018

[EN] The degradation of pesticide diuron has been explored by photoelectrocatalysis (PEC) under visible light illumination using two different WO3 nanostructures, obtained by anodization of tungsten. The highest degradation efficiency (73%) was obtained for WO3 nanosheets synthesized in the presence of small amounts of hydrogen peroxide (0.05 M). For that nanostructure, the kinetic coefficient for diuron degradation was 133% higher than that for the other nanostructure (anodized in the presence of fluoride anions). These results have been explained by taking into account the different architecture and dimensions of the two WO3 nanostructures under study.

Environmental EngineeringMaterials scienceNanostructurechemistry.chemical_element02 engineering and technology010501 environmental sciencesManagement Monitoring Policy and LawTungsten01 natural sciencesINGENIERIA QUIMICAchemistry.chemical_compoundPesticidesHydrogen peroxideWaste Management and Disposal0105 earth and related environmental sciencesNanoestructuresAnodizingGeneral Medicine021001 nanoscience & nanotechnologyWO3 nanostructures AnodizationElectroquímicachemistryChemical engineeringDiuronKinetic coefficientDegradation (geology)Photoelectrocatalysis0210 nano-technologyFluorideVisible spectrum
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Opals infiltrated with a stimuli-responsive hydrogel for ethanol vapor sensing

2013

We report on a novel class of optical materials for ethanol vapor sensing, based on polystyrene opals infiltrated with an innovative stimuli responsive hydrogel. We describe the fabrication process of the bare polystyrene opals and their subsequent infiltration. The optical characterization of the photonic crystal templates was performed to prove the good quality of the samples. Measurements on the infiltrated opals showed that the transmission spectra in the visible range strongly change at varying concentrations of ethanol vapor. The fabricated structures show a linear optical response in the visible range, for high values of ethanol concentration.

EthanolMaterials scienceFabricationNanostructure fabrication.technology industry and agricultureSettore ING-INF/02 - Campi ElettromagneticiNanotechnologySettore ING-INF/01 - ElettronicaElectronic Optical and Magnetic MaterialsOPALS (Ogren Plant Allergy Scale)Optical sensing and sensorchemistry.chemical_compoundchemistryChemical engineeringOptical materialsPhotonic crystalSettore CHIM/07 - Fondamenti Chimici Delle Tecnologiesense organsPolystyreneRefractive indexPhotonic crystalVisible spectrumOptical Materials Express
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Monitoring Electron-Photon Dressing in WSe 2

2016

Optical pumping of solids creates a non-equilibrium electronic structure where electrons and photons combine to form quasiparticles of dressed electronic states. The resulting shift of electronic levels is known as the optical Stark effect, visible as a red shift in the optical spectrum. Here we show that in a pump-probe setup we can uniquely define a non-equilibrium quasiparticle bandstructure that can be directly measurable with photoelectron spectroscopy. The dynamical photon-dressing (and undressing) of the many-body electronic states can be monitored by pump-probe time and angular resolved photoelectron spectroscopy (tr-ARPES) as the photon-dressed bandstructure evolves in time dependi…

Floquet theoryFloquet theoryPhotonphotoelectron spectroscopynonequilibrium bandstructurePhysics::OpticsBioengineering02 engineering and technologyElectronElectronic structure01 natural sciencesSettore FIS/03 - Fisica Della MateriaOptical pumpingsymbols.namesakeFirst-principles calculations0103 physical sciencesGeneral Materials Science010306 general physicsChemistryMechanical Engineeringpump-probe spectroscopyGeneral Chemistry021001 nanoscience & nanotechnologyCondensed Matter PhysicsStark effectQuasiparticlesymbolsCondensed Matter::Strongly Correlated ElectronsAtomic physics0210 nano-technologyVisible spectrumNano Letters
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Zinc complexes as fluorescent chemosensors for nucleic acids: new perspectives for a “boring” element

2014

Zinc(ii) complexes are effective and selective nucleic acid-binders and strongly fluorescent molecules in the low energy range, from the visible to the near infrared. These two properties have often been exploited to quantitatively detect nucleic acids in biological samples, in both in vitro and in vivo models. In particular, the fluorescent emission of several zinc(ii) complexes is drastically enhanced or quenched by the binding to nucleic acids and/or upon visible light exposure, in a different fashion in bulk solution and when bound to DNA. The twofold objective of this perspective is (1) to review recent utilisations of zinc(ii) complexes as selective fluorescent probes for nucleic acid…

Fluorescent DyeInorganic chemistrychemistry.chemical_elementLigandZincLigandsInorganic Chemistrychemistry.chemical_compoundCoordination ComplexesIn vivoNucleic AcidsMoleculeFluorescent DyesCoordination ComplexeNucleic AcidChemistryMedicine (all)Settore CHIM/08 - Chimica FarmaceuticaFluorescenceCombinatorial chemistryIn vitroZincSpectrometry FluorescenceSettore CHIM/03 - Chimica Generale E InorganicaNucleic acidDNAVisible spectrumDalton Transactions
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Front Cover: Visible‐Light‐Induced Cleavage of C−S Bonds in Thioacetals and Thioketals with Iodine as a Photocatalyst (ChemPhotoChem 2/2020)

2020

Front coverchemistryOrganic ChemistryPhotocatalysischemistry.chemical_elementCleavage (crystal)Physical and Theoretical ChemistryIodinePhotochemistryAnalytical ChemistryVisible spectrumChemPhotoChem
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Up-conversion luminescence of GdVO4:Nd3+/Er3+ and GdVO4:Nd3+/Ho3+ phosphors under 808 nm excitation

2018

All authors acknowledge to the COST Action CM1403: The European upconversion network - from the design of photon-upconverting nanomaterials to biomedical applications (2014–2018). The authors from the University of Belgrade acknowledge the financial support of the Ministry of Education, Science and Technological Development of the Republic of Serbia (Project Nos. 45020 and 172056 ). K. S. acknowledges the Latvian National Research Program IMIS2 (Grant No. 302/2012 ). T. G. acknowledges the ERDF PostDoc project No. 1.1.1.2/VIAA/1/16/215 ( 1.1.1.2/16/I/001 ).

Gadolinium vanadateMaterials scienceAnalytical chemistryPhosphor02 engineering and technologyUp-conversion010402 general chemistry01 natural sciencesIonInorganic Chemistry:NATURAL SCIENCES:Physics [Research Subject Categories]Electrical and Electronic EngineeringPhysical and Theoretical ChemistrySpectroscopyEr3+/Nd3+ [GdVO4]Organic Chemistry808-nm excitation021001 nanoscience & nanotechnologyAtomic and Molecular Physics and Optics0104 chemical sciencesElectronic Optical and Magnetic MaterialsWavelengthHo3+/Nd3+ [GdVO4]Up conversionCrystallite0210 nano-technologyLuminescenceExcitationVisible spectrumOptical Materials
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Light transmission of the human lens and its relation with aging

2011

Purpose To determine the visible light transmission of the human crystalline lens of persons of different ages, using both solar and incandescent illumination. Methods The spectral transmission of lens was measured by using the Perkin-Elmer 800 UV/VIS spectrophotometer. With these data we calculated the percentage of visible light transmission for solar illumination, simulated by the CIE D65 illuminant, and for incandescent illumination (A illuminant). Results The total amount of visible light transmitted by nine crystalline lenses is represented as a function of age: with solar illumination and with incandescent illumination and the comparison between both illuminants.In general, the amoun…

Incandescent light bulbLight transmissionMaterials sciencebusiness.industryBright-field microscopyStandard illuminantGeneral Medicinelaw.inventionCritical illuminationLens (optics)OphthalmologyOpticsTransmission (telecommunications)lawOptoelectronicssense organsbusinessVisible spectrumActa Ophthalmologica
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Near-UV to red-emitting charged bis-cyclometallated iridium(iii) complexes for light-emitting electrochemical cells

2011

Herein we report a series of charged iridium complexes emitting from near-UV to red using carbene-based N^C: ancillary ligands. Synthesis, photophysical and electrochemical properties of this series are described in detail together with X-ray crystal structures. Density Functional Theory calculations show that the emission originates from the cyclometallated main ligand, in contrast to commonly designed charged complexes using bidentate N^N ancillary ligands, where the emission originates from the ancillary N^N ligand. The radiative process of this series of compounds is characterized by relatively low photoluminescence quantum yields in solution that is ascribed to non-radiative deactivati…

Inorganic ChemistryPhotoluminescenceDenticitychemistryLigandExcited statechemistry.chemical_elementDensity functional theoryIridiumElectroluminescencePhotochemistryVisible spectrumDalton Trans.
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White light emitting silsesquioxane based materials: the importance of a ligand with rigid and directional arms

2022

The synthesis of a novel polyhedral oligomeric silsesquioxane functionalized with eight rigid and directional terpyridine-based arms (Ter-POSS) was successfully achieved via a Sonogashira reaction. The POSS based ligand was extensively characterized using different techniques including 1H, 13C and 29Si NMR as well as UV-Vis and fluorescence spectroscopies. The assembly of these nano-caged units in the presence of different transition metal ions (Fe2+, Zn2+ and Cu2+) as well as of a cation from the lanthanides (Eu3+) was investigated using absorption and emission spectroscopies. The final materials display an evident emission in different regions of the visible spectrum as a function of the …

LanthanidePOSS supramolecular chemistry lanthanidesMaterials scienceNanostructurechemistry.chemical_elementQuantum yieldSettore CHIM/06 - Chimica OrganicaFluorescenceSilsesquioxanechemistry.chemical_compoundCrystallographychemistryChemistry (miscellaneous)General Materials ScienceTerpyridineEuropiumVisible spectrumMaterials Advances
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