Quantum Size Effects
Mostrando 1-12 de 28 artigos, teses e dissertações.
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1. NEGATIVE EFFECTS ON PHOTOSYNTHESIS AND CHLOROPLAST PIGMENTS EXPOSED TO LEAD AND ALUMINUM: A META-ANALYSIS
ABSTRACT Toxic metals have become some of the main abiotic agents that influence the stress of organisms due to their numerous agricultural and industrial uses that result in bioaccumulation and toxicity at different levels, depending on the type and concentration in the environment. Aluminum and lead are present as a result of anthropogenic activities and c
CERNE. Publicado em: 2020-06
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2. 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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3. Efeitos da aperiodicidade sobre as transições quânticas em cadeias XY / Effects of aperiodicity on the quantum transitions in XY chains
Neste trabalho realizo uma adaptação do método de Ma, Dasgupta e Hu para o estudo e caracterização das transições de fase quânticas, induzidas por um campo transverso, em cadeias XY de spins 1/2, unidimensionais e aperiódicas, no espírito da adaptação correspondente para cadeias XXZ. O presente trabalho determina de forma analítica uma série de
Publicado em: 2011
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4. Estudo das propriedades estruturais e ópticas em materiais nanoestruturados a base de silício. / Study of structural and optical properties in nanostructured silicon based films.
The aim of this doctorate thesis is to enhance the knowledge in the research conducted along the Master degree based on the characterization and study of the structural and luminescent properties of silicon rich silicon oxynitride films (SiOxNy:H) deposited at low temperature by Plasma Enhanced Chemical Vapor Deposition (PECVD). The results of this study ind
Publicado em: 2009
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5. Estrutura eletrÃnica e propriedades espectroscÃpicas de compÃsitos polianilina/ouro: uma investigaÃÃo ab initio
In this dissertation we use ab initio quantum chemistry theoretical methods to examine possible effects that the presence of a small number of attached gold atoms could have upon the spectra of polyaniline (PANI) oligomers. We have investigated in special the theoretical fluorescence spectra of the gold-polyaniline composites, by using the Hartree-Fock appro
Publicado em: 2009
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6. Interação da matéria de vórtices com estruturas de defeitos : detecção das primeiras penetrações
This thesis results from a systematic study of the interactions between penetrated vortices and pinning centers carried out on structured superconductors films of YBCO, Nb and Pb. A regular array of pinning centers (antidots, ADs) was inserted in those samples by mechanical indentations (in YBCO and Nb films), and by a lithographic processes (Pb). The struct
Publicado em: 2009
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7. Sintese de nanoparticulas de oxidos semicondutores tipo caroço-casca em ambiente confinado / Synthesis of semiconductors oxides core-shell nanoparticles into confined ambient
Este trabalho reporta o estudo e o desenvolvimento da metodologia de síntese e de caracterização de nanopartículas isoladas e nanopartículas heteroestruturadas caroço@casca (NCC) envolvendo os óxidos semicondutores (TiO2, CeO2 e SnO2) impregnados em suporte poroso funcional (vidro poroso Vycor ¿ PVG). Empregou-se a metodologia de Ciclos de Impregnaç
Publicado em: 2009
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8. Estudo das atividades neurotoxica e miotoxica de uma fosfolipase A2 basica isolada do veneno total Bothrops marajoensis / Study of neurotoxic and myotoxic activities of a phospholipase A2 isolated from the Bothrops marajoensis venom
In the present work, the neuromuscular effects of the toxin Bmaj-9 isolated from the venom of Bothrops marajoensis in the laboratory of chemistry of proteins at Unicamp were studied. This toxin was assayed in biventer cervicis preparations of little chicken, phrenic diaphragm nerve of mice and in gastrocnemius muscles of mice. In birds preparation, Bmaj-9 ca
Publicado em: 2008
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9. Pinning of Abrikosov Vorticein MG B IND. 2 addition of NI nanoparticles / Aprisionamento dos Vortices de Abrikosov no MG B IND. 2 atraves da adição de nanoparticulas de NI
Since the discovery of the phenomenon of superconductivity in magnesium diboride (MgB2) in the year 2001, the vortex dynamics in this material has been widely studied, because this phenomenon can cause the destruction of the superconducting state. This study intends to assess the impact on the pinning of vortex and the behavior of the critical current densit
Publicado em: 2008
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10. Nanocomposites and nanostructures of II-VI and IV-VI semiconductors / Nanocompositos e nanoestruturas de semicondutores das familias II-VI e IV-VI
The development of nanostructures and their applications constitute one of the most exciting scientific areas. A great number of studies in this area concern the preparation methods. Generally, they are classified in physical and chemical methods. The former class is based on molecular beam and lithography techniques, while the latter involves chemical react
Publicado em: 2007
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11. Binding energy and photoionization cross-section in GaAs quantum well-wires and quantum dots: magnetic field and hydrostatic pressure effects
Using a variational procedure for a hydrogenic donor-impurity we have investigated the influence of an axial magnetic field and hydrostatic pressure in the binding energy and the impurity-related photoionization cross-section in 1D and 0D GaAs low dimensional systems. Our results are given as a function of the radius, the impurity position, the polarization
Brazilian Journal of Physics. Publicado em: 2006-06
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12. Laser de faces clivadas com regiões ativas nanoestruturadas bombeados por injeção eletronica / Cleaved face laser with nanostructured active region pumped by electronic injection
This masters dissertation presents the theoretical studies on the calculation of optical gain in nanostructures based on the InGaAs/InGaAsP/InP system. From the time dependent perturbation theory, where perturbation is the interaction of an electromagnetic wave with matter, and the Kanes theory for semiconductors band structure, relating the transition m
Publicado em: 2006