Navegação Ciências Exatas e da Terra por Título
Resultados 5728-5747 de 6559
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S-wave meson-nucleon scattering in an su(3) cloudy bag model
(1985) [Artigo de periódico]The cloudy bag model (CBM) is extended to incorporate chiral SU(3)XSU(3) symmetry, in order to describe 5-wave KN and KN scattering. In spite of the large mass of the kaon, the model yields reasonable results once the ... -
Symmetry breaking in d-dimensional self-gravitating systems
(2013) [Artigo de periódico]Systems with long-range interactions, such as self-gravitating clusters and magnetically confined plasmas, do not relax to the usual Boltzmann-Gibbs thermodynamic equilibrium, but become trapped in quasistationary states ... -
Symmetry plane correlations in Pb–Pb collisions at √sNN = 2.76 TeV
(2023) [Artigo de periódico]A newly developed observable for correlations between symmetry planes, which characterize the direction of the anisotropic emission of produced particles, is measured in Pb–Pb collisions at √sNN = 2.76 TeV with ALICE. This ... -
Synthesis and characterization in solution and in the solid state of the palladium aryl bromide complexes [Pd(Ar)Br{(S)-BINAP}] : formation of cyclopalladated complexes and direct observation of a C-N reductive elimination to form heterocycles
(2004) [Artigo de periódico]As reações de uma mistura [Pd2(dba)3]/P(o-tolyl)3 (1/4) com brometos de arila orto substituídos conduziram aos dímeros [Pd(Ar)(m-Br){P(o-tolyl)3)}]2 que, após adição de 2 equiv. de (S)-BINAP formaram os complexos ... -
Synthesis and characterization of [Cd8Cl2Se(SePh)12(PCy3)2]•2.5CH3OH
(2010) [Artigo de periódico]Neste artigo estamos apresentando a síntese do composto [Cd8Cl2(μ4-Se)(SePh)12(PCy3)2]·2.5CH3OH pela reação de Cd(SePh)2 com CdCl2 e triciclohexilfosfina em metanol em um reator de aço inoxidável sob condições solvotérmicas ... -
Synthesis and characterization of some novel tetrazole liquid crystals
(2013) [Artigo de periódico]The synthesis and characterization of new 4-[(2-alkyl)-2H-tetrazol-5-yl]phenyl 4-alkyloxybenzoates (5a–i) and 5-{4-[(4-substituted)benzyloxy]phenyl}-2-alkyl-2H-tetrazoles (7a–e) are reported. The reported tetrazoles contain ... -
Synthesis and enzymatic evaluation of the guanosine analogue 2-amino-6-mercapto-7-methylpurine ribonucleoside (MESG). Insights into the phosphorolysis reaction mechanism based on the blueprint transition state: sn1 or sn2
(2010) [Artigo de periódico]A modificação experimental para a síntese do MESG (2-amino-6-mercapto-7-metilpurina ribonucleosídeo) 1 foi realizada com sucesso e sua caracterização total apresentada. ESI(+)-MSMS em alta resolução foram realizados indicando ... -
Synthesis and mesomorphic properties of side chain liquid-crystalline biphenyl-phenyl polyacrylates
(2006) [Artigo de periódico]A síntese e a caracterização de dois cristais líquidos poliacrilatos, de cadeia lateral contendo o sistema bifenil-fenila como unidade central são descritos. A cadeia terminal é derivada da L-isoleucina. Em cada caso, o ... -
Synthesis and photophysical characterization of novel ESIPT triazinyl-benzazole derivatives
(2015) [Artigo de periódico]In this work, the synthesis, characterization and photophysical study of new derivatives of triazinyl-benzazoles with fluorescence by excited-state intramolecular proton transfer (ESIPT) are presented. It regards the ... -
Synthesis and thermal behavior of new liquid crystals arylaldoxime esters
(2012) [Artigo de periódico]Uma série de cristais líquidos derivados de ésteres arilaldoximas foi sintetizada e caracterizada via espectroscopia de 1H, 13C RMN, ATR/IV-FT e análise elementar. A estabilidade química e fotofísica desses compostos foram ... -
Synthesis, characterization and catalytic evaluation of magnetically recoverable SrO/CoFe2O4 nanocatalyst for biodiesel production from babassu oil transesterification
(2018) [Artigo de periódico]Biodiesel production has gained a lot of attention due to its environmental benefits and production from renewable sources. Here, it is reported a magnetically recoverable catalyst of SrO immobilized on a CoFe2O4 support ... -
Synthesis, characterization and ethylene oligomerization studies of chromium complexes bearing imino-furfural ligands
(2014) [Artigo de periódico]A series of chromium(III) complexes bearing imino-furfural ligands (Cr1-Cr4) were synthesized and characterized by high-resolution mass spectrometry (HRMS). All chromium precatalysts, activated with methylaluminoxane (MAO), ... -
Synthesis, characterization and photophysical properties of ESIPT reactive triazine derivatives
(2012) [Artigo de periódico]Uma série de quatro compostos fotoativos derivados da triazina foi obtida a partir da substituição nucleofílica aromática no cloreto cianúrico. Os compostos foram caracterizados por espectroscopia de infravermelho (IR) e ... -
Synthesis of 5-hydroxymethylfurfural from dehydration of fructose and glucose using ionic liquids
(2014) [Artigo de periódico]The production of 5-hydroxymethylfurfural (HMF) from sugars dehydration is an alternative for obtaining starting materials for the production of polyesters, polyamides and polyurethanes, due to the development of the new ... -
Synthesis of alkylseleno-carbohydrates and evaluation of their antioxidant properties
(2015) [Artigo de periódico]In the present study, we describe the synthesis of alkylseleno carbohydrates with different sugar scaffolds and the evaluation of their antioxidant activity profile. A compound possessing a C8 alkyl chain presented the ... -
Synthesis of dihydropyrimidin-2-one/thione library and cytotoxic activity against the human U138-MG and rat C6 glioma cell lines
(2011) [Artigo de periódico]Duas séries de 4-aril-3,4-diidropirimidin-2(1H)-(tio)onas incluindo monastrol (1a), foram sintetizadas por uma metodologia não agressiva ao meio ambiente baseada no uso combinado de ácido cítrico ou ácido oxálico na presença ... -
Synthesis of GaN by N ion implantation in GaAs (001)
(1995) [Artigo de periódico]Both the hexagonal and cubic GaN phases were synthesized in GaAs ~001! by 50 keV N ion implantation at 380 °C and subsequent furnace annealing at 850–950 °C for 10 min–2 h. For a fluence of 1.531017 cm22, transmission ... -
Synthesis of imidazole-derived ionic liquids from monoterpenes by means of the sonogashira reaction
(2012) [Artigo de periódico]This work reports the functionalization of monoterpenoids with 2-iodo-1-methyl-1H-imidazole using Sonogashira crosscoupling reactions. Natural monoterpenes were also modified to obtain the corresponding alkynes which were ... -
Synthesis of limonene B-amino alcohol derivatives in support of new antileishmanial therapies
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Synthesis of magnetic nanoparticles functionalized with histidine and nickel to immobilize His-tagged enzymes using β-galactosidase as a model
(2021) [Artigo de periódico]The aim of this study was to synthesize iron magnetic nanoparticles functionalized with histidine and nickel (Fe3O4-His-Ni) to be used as support materials for oriented immobilization of His-tagged recombinant enzymes of ...
