Quantum Well
Mostrando 13-24 de 299 artigos, teses e dissertações.
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13. Synthesis of Hydrotalcite-Supported CdTe Semiconductor Nanocrystals for Electrochemical Detection of Ciprofloxacin
In this work, CdTe quantum dots (QDs) were controllably grown onto the surface of layered double hydroxide (LDH) aiming to develop a sensitive and selective method for the electrochemical detection of ciprofloxacin (CPX). Emission and absorption spectroscopy results as well as high-resolution transmission electron microscopy (HRTEM) images evidenced the form
J. Braz. Chem. Soc.. Publicado em: 23/05/2019
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14. Solution of the 1d Schrödinger Equation for a Symmetric Well
Abstract We suggest a mathematical potential well with spherical symmetry and apply to the 1d Schrödinger equation. We use some well known techniques as Stationary Perturbation Theory and WKB to gain insight about the solutions and compare them each other. Finally, we solve the 1d Schrödinger equation using a numerical approach with the so-called Numerov t
Rev. Bras. Ensino Fís.. Publicado em: 25/04/2019
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15. RM1 Semiempirical Model: Chemistry, Pharmaceutical Research, Molecular Biology and Materials Science
In this review, we show improvements to the semiempirical quantum chemical method RM1 and present a wide range of its applications as reported by researchers of various areas, such as theoretical, organic, physical, analytical, and inorganic chemistry, as well as their interfaces with medicinal chemistry, biology, and materials science. Success of RM1 is see
J. Braz. Chem. Soc.. Publicado em: 2019-04
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16. Computer-Guided Total Synthesis of Natural Products. Recent Examples and Future Perspectives
Quantum chemical calculations of nuclear magnetic resonance (NMR) shifts and coupling constants have been extensively employed in recent years mainly to facilitate structural elucidation of organic molecules. When the results of such calculations are used to determine the most likely structure of a natural product in advance, guiding the subsequent synthetic
J. Braz. Chem. Soc.. Publicado em: 2018-05
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17. Controlled synthesis of noble metal nanomaterials: motivation, principles, and opportunities in nanocatalysis
ABSTRACT This review describes some principles of the controlled synthesis of metal nanoparticles, focusing on how the fundamental understanding of their synthesis in the solution-phase can be put to tailor size, shape, composition, and architecture. The maneuvering over these parameters not only enable the tuning of properties, but also the maximization and
An. Acad. Bras. Ciênc.. Publicado em: 16/04/2018
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18. AVALIAÇÃO DO DESEMPENHO DE UMA FASE SENSORA DE POLIURETANO POR MEIO DA ENERGIA DE GIBBS DE SOLVATAÇÃO E ESPECTROSCOPIA DE INFRAVERMELHO PARA DETERMINAÇÃO DE TOLUENO EM ÁGUA
A novel sensing phase of polyurethane was predicted by quantum chemical calculations as capable of detecting toluene, with the experimental results revealing a limit of detection of 1.4 mg L-1 in the determination of toluene in water samples. The quantum chemical computational strategy was validated by assessing the impact of the polymer matrix sensing phase
Quím. Nova. Publicado em: 2018-04
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19. Vitality of lichens under different light climates in an Araucaria forest (Pró-Mata RS, South Brazil) as determined by chlorophyll fluorescence
ABSTRACT The vitality of 64 lichen species (107 individual lichen thalli) growing under different light climates in an Araucaria forest in South Brazil was analyzed by chlorophyll fluorescence. Study sites were grouped according to their local light availability under full sunlight (about 2200 µmol m-2 s-1): 1 = low light, up to 20 µmol m-2 s-1; 2 = medium
Acta Bot. Bras.. Publicado em: 08/01/2018
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20. PONTOS QUÂNTICOS AMBIENTALMENTE AMIGÁVEIS: DESTAQUE PARA O ÓXIDO DE ZINCO
Semiconductor nanocrystals with sizes in the quantum confinement regime (2-10 nm) present special physical and chemical properties. Additionally, environment-friendly quantum dots (QDs), as zinc oxide and zinc sulfide, offer many practical usages. Herein the ZnO semiconductor nanocrystals properties will be preferentially explored, such as its luminescence,
Quím. Nova. Publicado em: 2017-10
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21. Sinais de fundo em análise instrumental: uma discussão essencial em cursos de graduação
Understanding instrumental analysis is essential for obtaining reliable analytical results required by chemists in a variety of research areas and industrial activities. All instrumental techniques involve undesirable background (BG) signals originated either from concomitants in the sample or by spurious (e.g. electrical or optical) effects intrinsically re
Quím. Nova. Publicado em: 2017-02
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22. COMPETITION BETWEEN THE REACTION MEDIUM AND NANOSTRUCTURED ZnO IN THE PHOTOCATALYTIC DEGRADATION OF ANTHRACENE. TOWARD AN OPTIMAL PROCESS FOR POLYCYCLIC AROMATIC HYDROCARBONS REMEDIATION
Contamination with polycyclic aromatic hydrocarbons (PAHs) is considered an important health issue due to the toxicity of these compounds. Photocatalytic degradation of anthracene, a representative molecule of PAHs, using the high quantum yield semiconductor ZnO, has been reported. The solubility of anthracene in water makes necessary to use mixtures with or
Quím. Nova. Publicado em: 2017-01
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23. Semi-Empirical Quantum Chemistry Method for Pre-Polymerization Rational Design of Ciprofloxacin Imprinted Polymer and Adsorption Studies
It is well known that selectivity of molecularly imprinted polymers (MIPs) depends on adequate choice of functional monomer before the experimental synthesis. Computational simulation seems to be an ideal way to produce selective MIPs. In this work, we have proposed the use of semi-empirical simulation to obtain the best monomer able to strongly interact wit
J. Braz. Chem. Soc.. Publicado em: 2016-01
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24. QUANTUM INSPIRED PARTICLE SWARM COMBINED WITH LIN-KERNIGHAN-HELSGAUN METHOD TO THE TRAVELING SALESMAN PROBLEM
ABSTRACT The Traveling Salesman Problem (TSP) is one of the most well-known and studied problems of Operations Research field, more specifically, in the Combinatorial Optimization field. As the TSP is a NP (Non-Deterministic Polynomial time)-hard problem, there are several heuristic methods which have been proposed for the past decades in the attempt to solv
Pesqui. Oper.. Publicado em: 2015-12