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1.
Angew Chem Int Ed Engl ; 53(37): 9889-92, 2014 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-25044327

RESUMO

A new method for the synthesis of highly substituted naphthyridine-based polyheteroaromatic compounds in high yields proceeds through rhodium(III)-catalyzed multiple C-H bond cleavage and C-C and C-N bond formation in a one-pot process. Such highly substituted polyheteroaromatic compounds have attracted much attention because of their unique π-conjugation, which make them suitable materials for organic semiconductors and luminescent materials. Furthermore, a possible mechanism, which involves multiple chelation-assisted ortho C-H activation, alkyne insertion, and reductive elimination, is proposed for this transformation.

2.
Appl Ergon ; 60: 207-219, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28166879

RESUMO

Focusing on the theme of direct manipulation, in this study, we proposed a new and innovative tangible user interface (TUI) design concept for a manipulative digital drawing pen. Based on interviews with focus groups brainstorming and experts and the results of a field survey, we selected the most suitable tangible user interface for children between 4 and 7 years of age. Using the new tangible user interface, children could choose between the brush tools after touching and feeling the various patterns. The thickness of the brush could be adjusted by changing the tilt angle. In a subsequent experimental process we compared the differences in performance and subjective user satisfaction. A total of sixteen children, aged 4-7 years participated in the experiment. Two operating system experiments (the new designed tangible digital drawing pen and traditional visual interface-icon-clicking digital drawing pens) were performed at random and in turns. We assessed their manipulation performance, accuracy, brush stroke richness and subjective evaluations. During the experimental process we found that operating functions using the direct manipulation method, and adding shapes and semantic models to explain the purpose of each function, enabled the children to perform stroke switches relatively smoothly. By using direct manipulation digital pens, the children could improve their stroke-switching performance for digital drawing. Additionally, by using various patterns to represent different brushes or tools, the children were able to make selections using their sense of touch, thereby reducing the time required to move along the drawing pens and select icons (The significant differences (p = 0.000, p < 0.01) existed in the manipulation times for drawing thick lines using the crayon function of the two (new and old) drawing pens (new 5.8750 < old 10.7500)). The addition of direct manipulation movements to drawing operations enhanced the drawing results, thereby increasing the children's enjoyment of drawing with tangible digital drawing pens.


Assuntos
Desenho de Equipamento , Interface Usuário-Computador , Criança , Pré-Escolar , Gráficos por Computador , Ergonomia , Feminino , Humanos , Masculino , Análise e Desempenho de Tarefas , Tato
3.
Org Lett ; 15(7): 1468-71, 2013 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-23477600

RESUMO

Palladium-catalyzed oxidative carbonylation of N-sulfonyl-2-aminobiaryls through C-H bond activation and C-C, C-N bond formation under TFA-free and milder conditions has been developed. The reaction tolerates a variety of substrates and provides biologically important phenanthridinone derivatives in yields up to 94%.


Assuntos
Monóxido de Carbono/química , Paládio/química , Fenantrenos/síntese química , Alcaloides de Amaryllidaceae/síntese química , Alcaloides de Amaryllidaceae/química , Alcaloides de Amaryllidaceae/farmacologia , Catálise , Técnicas de Química Combinatória , Estrutura Molecular , Oxirredução , Fenantrenos/química , Fenantrenos/farmacologia
4.
Chem Commun (Camb) ; 49(100): 11797-9, 2013 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-24212301

RESUMO

Palladium-catalyzed oxidative carbonylation of 2-arylphenols through C-H bond activation and C-C and C-O bond formation under acid-base free and mild conditions has been developed. The reaction tolerates a variety of substrates and provides biologically important benzopyranone derivatives in up to 87% isolated yield.


Assuntos
Benzopiranos/síntese química , Monóxido de Carbono/química , Paládio/química , Fenol/química , Benzopiranos/química , Catálise , Estrutura Molecular
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