Red Shift
Mostrando 1-12 de 150 artigos, teses e dissertações.
-
1. Blue Glow Sticks: Cinnamic Acids and Arylacrylonitriles with Liquid-Crystalline Properties and Highly Fluorescent
Five new π-conjugated chromophores derived from acrylic acid and acrylonitrile were synthesized and their thermal and photophysical behaviors were analyzed. They were designed and synthesized through Knoevenagel condensations between arylacetylenebenzaldehydes and a methylene group activated from cyanoacetic and malonic acids. The characterization of the ta
J. Braz. Chem. Soc.. Publicado em: 2021-01
-
2. The Effect of Red Pigment and Photo Stabilizers on the Photo Degradation of Polypropylene Films
The aim of this work was to evaluate the photo degradation of PP films containing photo stabilizers, a ultraviolet absorber and a hindered amine light stabilizer (HALS), and a red pigment. The films were produced by extrusion and exposed to the UV radiation in the laboratory for up to 15 weeks. The results obtained from FTIR, UV-vis and colorimetry showed th
Mat. Res.. Publicado em: 11/04/2019
-
3. Effect of Hydrostatic Pressure on the Fluorescence of Tryptophan in the Presence of Metal Ions Running title: Effect of pressure on the tryptophan
ABSTRACT The effect of pressure on the fluorescence of tryptophan in the presence of metal ions was studied by fluorescence spectrometry. It was found that at 60 MPa, the fluorescence intensity of M/Trp mixtures (M represented metal ions) increased compared to that at atmosphere pressure. The relative fluorescence efficiency of M/Trp mixtures increased with
Braz. arch. biol. technol.. Publicado em: 29/11/2018
-
4. Silver and gold nanoparticles from tannic acid: synthesis, characterization and evaluation of antileishmanial and cytotoxic activities
Abstract Gold (Au0) and silver (Ag0) nanoparticles were synthesized using tannic acid (TA) as both reducing and stabilizer. Nanoparticles formation, stability, and interaction with TA were compared to citrate-coated nanoparticles and monitored by UV-Vis, zeta potential, and transmission electron microscopy. TA coating resulted in a red-shift and broadening o
An. Acad. Bras. Ciênc.. Publicado em: 19/07/2018
-
5. Characterization of Sn Doped ZnS Thin Films Synthesized by CBD
Zinc sulphide (ZnS) thin film were prepared using chemical bath deposition (CBD) process and tin (Sn) doping was successfully carried out in ZnS. Structural, morphological and microstructural characterization was carried out using XRD, TEM, FESEM and EDX. XRD and SAED pattern confirms presence of hexagonal phase. Reitveld analysis using MAUD software was use
Mat. Res.. Publicado em: 09/02/2017
-
6. SPECTROSCOPIC STUDY OF EFFECTS OF TETRAALKYLAMMONIUM CATIONS ON F--SENSING PROPERTIES OF CALIX[4]PYRROLE BORADIAZAINDACENE DYE
A novel meso-tetracyclohexylcalix[4]pyrrole-based boradiazaindacene dye 3 was synthesized and characterized. F--binding properties of the dye in the presence of tetrabutylammonium (TBA+), tetraethylammonium (TEA+), and tetramethylammonium (TMA+) counter ions were investigated by UV-Vis, fluorescence, and NMR spectroscopies. Dye 3 displayed various degrees of
Quím. Nova. Publicado em: 2016-08
-
7. First Principles Study on the Electronic Structure and Optical Property of Nd-C Codoped Anatase TiO 2
ABSTRACT Band structures, density of states, and absorption spectra of pure, Nd doped, C doped, and Nd-C codoped TiO2 are calculated using first-principles based on density functional theory. Calculation results show that Nd 4f state forms empty impurity energy levels below conduction band, and C 2p state together with Nd 2f state forms occupied impurity ene
Matéria (Rio J.). Publicado em: 2016-06
-
8. Diet shift of Red Belly Pacu Piaractus brachypomus (Cuvier, 1818) (Characiformes: Serrasalmidae), a Neotropical fish, in the Sepik-Ramu River Basin, Papua New Guinea
Introduction of fish species is a globally widespread practice that causes losses of native species and homogenization of diversity within and across continents. Diet assessments are important tools to depict the ecological function of species introduced into novel ecosystem and possible direct and indirect ecological effects. In this study, we compare the d
Neotrop. ichthyol.. Publicado em: 09/01/2015
-
9. A INFLUÊNCIA DA LIGAÇÃO DE HIDROGÊNIO EM REAÇÕES QUÍMICAS: REAÇÃO DE PRILESCHAJEW
Theoretical analysis at the BHandHLYP/6-311++G(d,p) level of theory with the support of QTAIM calculations was used to reinvestigate the structure of an intermolecular system formed between ethylene oxide (C2H4O) and formic acid (HCO2H) after the epoxidation known as the Prileschajew reaction. Geometric and infrared vibration results revealed that HO2CH form
Quím. Nova. Publicado em: 2015-01
-
10. Estudos ópticos e cristalográficos de ZnS dopado com Cr
Foram sintetizados nanocristais de ZnS puros e dopados com 10% cromo pela rota química de co-precipitação. As amostras foram caracterizadas pela técnica de difração de raios X (DRX), espectroscopia de infravermelho com transformada de Fourier (FTIR) e espectrometria UV-Visível. O parâmetro de rede 'a' diminui e o tamanho de grão aumenta com o aument
Cerâmica. Publicado em: 2014-09
-
11. Synthesis and characterization of water-dispersed CdSe/CdS core-shell quantum dots prepared via layer-by-layer method capped with carboxylic-functionalized poly(vinyl alcohol)
The main goal of this work was to synthesize CdSe/CdS (core-shell) nanoparticles stabilized by polymer ligand using entirely aqueous colloidal chemistry at room temperature. First, the CdSe core was prepared using precursors and acid-functionalized poly(vinyl alcohol) as the capping ligand. Next, a CdS shell was grown onto the CdSe core via the layer-by-laye
Mat. Res.. Publicado em: 09/05/2014
-
12. A regra de Bent contextualiza a força da ligação de hidrogênio em clusters trimoleculares
This article presents a theoretical study of the molecular properties of trimolecular clusters of CnHm∙∙∙HCN∙∙∙HX formed by the ϖ∙∙∙H and n∙∙∙H hydrogen bonds. The interaction strengths of these interactions are in line with the variations in s-character, and independently, the red-shift rise whether stronger or weaker bound systems
Quím. Nova. Publicado em: 2014