Search results for "electromagnetic [radiation]"

showing 3 items of 873 documents

A DFT Study of Linear Gold–Thiolate Superclusters Absorbing in the Therapeutic NIR Window

2015

A series of linear clusters up to an aspect ratio of 1:6, formed as multimers of smaller clusters with an icosahedral Au13(5+) core having an eight-electron superatom configuration, are computationally predicted to have a greatly enhanced size-dependent absorption in the near-infrared (NIR) region extending to the biologically important NIR window. A novel structural model is presented for the previously isolated thiol-stabilized Au54(SR)30 cluster, where the metal core is formed as a heterodimer of the cores of the known Au25(SR)18(-/0) and Au38(SR)24 clusters.

ta114Icosahedral symmetryChemistrySuperatomNanotechnologyAspect ratio (image)MetalCore (optical fiber)Crystallographyvisual_artvisual_art.visual_art_mediumCluster (physics)General Materials ScienceDensity functional theoryPhysical and Theoretical ChemistryAbsorption (electromagnetic radiation)ta116The Journal of Physical Chemistry Letters
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Laser fluence, repetition rate and pulse duration effects on paint ablation

2006

Abstract The efficiency (mm3/(J pulse)) of laser ablation of paint was investigated with nanosecond pulsed Nd:YAG lasers (λ = 532 nm) as a function of the following laser beam parameters: pulse repetition rate (1–10,000 Hz), laser fluence (0.1–5 J/cm2) and pulse duration (5 ns and 100 ns). In our study, the best ablation efficiency (η ≅ 0.3 mm3/J) was obtained with the highest repetition rate (10 kHz) at the fluence F = 1.5 J/cm2. This ablation efficiency can be associated with heat accumulation at high repetition rate, which leads to the ablation threshold decrease. Despite the low thermal diffusivity and the low optical absorption of the paint (thermal confinement regime), the ablation th…

thermal confinement regimeMaterials sciencePACS: 81.65 Cf; 42.62 Cf; 61.82 Msmedicine.medical_treatmentGeneral Physics and Astronomy02 engineering and technology01 natural sciencesFluencelaw.invention010309 opticsOpticslaw0103 physical sciencesmedicineAbsorption (electromagnetic radiation)Laser ablationPulse (signal processing)business.industryrepetition ratePulse duration[CHIM.MATE]Chemical Sciences/Material chemistrySurfaces and InterfacesGeneral ChemistryNanosecond021001 nanoscience & nanotechnologyCondensed Matter PhysicsAblationLaserpaint strippingLaser ablationSurfaces Coatings and Filmspulse duration[ CHIM.MATE ] Chemical Sciences/Material chemistryOptoelectronics0210 nano-technologybusinessApplied Surface Science
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The Ti-influence on the tourmaline color

2008

Titanium was examined in different black tourmalines by spectrophotometric analyses in the region between 12500 and 27000 cm-1 (800-370 nm) using a microscope spectrophotometer MPV-5P, Leitz (Germany), and chemically analyzed on an electron microprobe Camebax Microbeam, Cameca (France) in WDS Mode. Fourteen tourmaline samples with their face oriented parallel to the principal axis, cut and polished down to thin sections, showed polarized spectra of two broad absorption bands at approximately 14000 cm-1 (715 nm) and 24000 cm-1 (417 nm). Precision thickness measurements were used to calculate the absorption coefficients α. For the absorption around 24000 cm-1, a linear correlation was observe…

tourmalineMicroscopeTourmalineChemistryAnalytical chemistrychemistry.chemical_elementGeneral ChemistryElectron microprobeMicrobeamIntervalence charge transferSpectral linelaw.inventionlawIVCT effecttitaniumAbsorption (electromagnetic radiation)Titanium
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