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 | Acesso ao texto completo restrito à biblioteca da Embrapa Amazônia Oriental. Para informações adicionais entre em contato com cpatu.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Amazônia Oriental. |
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Data corrente: |
27/02/2008 |
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Data da última atualização: |
23/11/2022 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
DAVIDSON, E. A.; CARVALHO, C. J. R. de; FIGUEIRA, A. M.; ISHIDA, F. Y.; OMETTO, J. P. H. B.; NARDOTO, G. B.; SABÁ, R. T.; HAYASHI, S. N.; LEAL, E. C.; VIEIRA, I. C. G.; MARTINELLI, L. A. |
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Afiliação: |
Eric A. Davidson, The Woods Hole Research Center; CLAUDIO JOSE REIS DE CARVALHO, CPATU; Adelaine Michela Figueira, CENA; Françoise Yoko Ishida, CENA; Jean Pierre H. B. Ometto, CENA; Gabriela B. Nardoto, CENA; Renata Tuma Sabá, bolsista CPATU; Sanae N. Hayashi, MPEG; Eliane C. Leal, MPEG; Ima Célia G. Vieira, MPEG; Luiz A. Martinelli, CENA. |
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Título: |
Recuperation of nitrogen cycling in Amazonian forests following agricultural abandonment. |
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Ano de publicação: |
2007 |
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Fonte/Imprenta: |
Nature, v. 447, n. 7147, p. 995-998, Jun. 2007. |
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DOI: |
10.1038/nature05900 |
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Idioma: |
Português |
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Notas: |
Disponível também on-line. |
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Conteúdo: |
Phosphorus (P) is generally considered the most common limiting nutrient for productivity of mature tropical lowland forests growing on highly weathered soils1, 2, 3, 4, 5. It is often assumed that P limitation also applies to young tropical forests, but nitrogen (N) losses during land-use change may alter the stoichiometric balance of nutrient cycling processes. In the Amazon basin, about 16% of the original forest area has been cleared6, and about 30?50% of cleared land is estimated now to be in some stage of secondary forest succession following agricultural abandonment7. Here we use forest age chronosequences to demonstrate that young successional forests growing after agricultural abandonment on highly weathered lowland tropical soils exhibit conservative N-cycling properties much like those of N-limited forests on younger soils in temperate latitudes. As secondary succession progresses, N-cycling properties recover and the dominance of a conservative P cycle typical of mature lowland tropical forests re-emerges. These successional shifts in N:P cycling ratios with forest age provide a mechanistic explanation for initially lower and then gradually increasing soil emissions of the greenhouse gas nitrous oxide (N2O). The patterns of N and P cycling during secondary forest succession, demonstrated here over decadal timescales, are similar to N- and P-cycling patterns during primary succession as soils age over thousands and millions of years, thus revealing that N availability in terrestrial ecosystems is ephemeral and can be disrupted by either natural or anthropogenic disturbances at several timescales. MenosPhosphorus (P) is generally considered the most common limiting nutrient for productivity of mature tropical lowland forests growing on highly weathered soils1, 2, 3, 4, 5. It is often assumed that P limitation also applies to young tropical forests, but nitrogen (N) losses during land-use change may alter the stoichiometric balance of nutrient cycling processes. In the Amazon basin, about 16% of the original forest area has been cleared6, and about 30?50% of cleared land is estimated now to be in some stage of secondary forest succession following agricultural abandonment7. Here we use forest age chronosequences to demonstrate that young successional forests growing after agricultural abandonment on highly weathered lowland tropical soils exhibit conservative N-cycling properties much like those of N-limited forests on younger soils in temperate latitudes. As secondary succession progresses, N-cycling properties recover and the dominance of a conservative P cycle typical of mature lowland tropical forests re-emerges. These successional shifts in N:P cycling ratios with forest age provide a mechanistic explanation for initially lower and then gradually increasing soil emissions of the greenhouse gas nitrous oxide (N2O). The patterns of N and P cycling during secondary forest succession, demonstrated here over decadal timescales, are similar to N- and P-cycling patterns during primary succession as soils age over thousands and millions of years, thus revealing that N availabi... Mostrar Tudo |
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Palavras-Chave: |
Brasil. |
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Thesagro: |
Agricultura; Floresta; Nitrogênio. |
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Thesaurus Nal: |
Amazonia. |
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Categoria do assunto: |
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Marc: |
LEADER 02556naa a2200325 a 4500
001 1409000
005 2022-11-23
008 2007 bl uuuu u00u1 u #d
024 7 $a10.1038/nature05900$2DOI
100 1 $aDAVIDSON, E. A.
245 $aRecuperation of nitrogen cycling in Amazonian forests following agricultural abandonment.$h[electronic resource]
260 $c2007
500 $aDisponível também on-line.
520 $aPhosphorus (P) is generally considered the most common limiting nutrient for productivity of mature tropical lowland forests growing on highly weathered soils1, 2, 3, 4, 5. It is often assumed that P limitation also applies to young tropical forests, but nitrogen (N) losses during land-use change may alter the stoichiometric balance of nutrient cycling processes. In the Amazon basin, about 16% of the original forest area has been cleared6, and about 30?50% of cleared land is estimated now to be in some stage of secondary forest succession following agricultural abandonment7. Here we use forest age chronosequences to demonstrate that young successional forests growing after agricultural abandonment on highly weathered lowland tropical soils exhibit conservative N-cycling properties much like those of N-limited forests on younger soils in temperate latitudes. As secondary succession progresses, N-cycling properties recover and the dominance of a conservative P cycle typical of mature lowland tropical forests re-emerges. These successional shifts in N:P cycling ratios with forest age provide a mechanistic explanation for initially lower and then gradually increasing soil emissions of the greenhouse gas nitrous oxide (N2O). The patterns of N and P cycling during secondary forest succession, demonstrated here over decadal timescales, are similar to N- and P-cycling patterns during primary succession as soils age over thousands and millions of years, thus revealing that N availability in terrestrial ecosystems is ephemeral and can be disrupted by either natural or anthropogenic disturbances at several timescales.
650 $aAmazonia
650 $aAgricultura
650 $aFloresta
650 $aNitrogênio
653 $aBrasil
700 1 $aCARVALHO, C. J. R. de
700 1 $aFIGUEIRA, A. M.
700 1 $aISHIDA, F. Y.
700 1 $aOMETTO, J. P. H. B.
700 1 $aNARDOTO, G. B.
700 1 $aSABÁ, R. T.
700 1 $aHAYASHI, S. N.
700 1 $aLEAL, E. C.
700 1 $aVIEIRA, I. C. G.
700 1 $aMARTINELLI, L. A.
773 $tNature$gv. 447, n. 7147, p. 995-998, Jun. 2007.
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Embrapa Amazônia Oriental (CPATU) |
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Registro Completo
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Biblioteca(s): |
Embrapa Instrumentação. |
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Data corrente: |
02/10/2023 |
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Data da última atualização: |
02/10/2023 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
A - 1 |
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Autoria: |
SILVA, R. M. e; SOUZA, F. L.; DIAS, E.; SILVA, G. T. S. T. da; DÚRAN, F. E.; REGO, A.; HIGGINS, D.; RIBEIRO, C. |
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Afiliação: |
Department of Chemical Engineering, McMaster University, Hamilton, Ontario, Canada; Department of Chemistry and Molecular Physics, Institute of Chemistry of Sao Carlos, University of Sao Paulo, Brazil; Department of Chemistry and Molecular Physics, Institute of Chemistry of Sao Carlos, University of Sao Paulo, Brazil; Interdisciplinary Laboratory of Electrochemistry and Ceramics, Department of Chemistry, Federal University of Sao Carlos; Department of Fuel and Hydrogen Cells, Nuclear and Energy Research Institute; Department of Chemical Engineering, McMaster University, Hamilton, Ontario, Canada; Department of Chemical Engineering, McMaster University, Hamilton, Ontario, Canada; CAUE RIBEIRO DE OLIVEIRA, CNPDIA. |
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Título: |
The role of TiO2:SnO2 heterojunction for partial oxidation of methane by photoelectrocatalytic process at room temperature. |
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Ano de publicação: |
2023 |
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Fonte/Imprenta: |
Journal of Alloys and Compounds, v. 968, 172090, 2023. |
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Páginas: |
7 p. |
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ISSN: |
0925-8388 |
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DOI: |
https://doi.org/10.1016/j.jallcom.2023.172090 |
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Idioma: |
Inglês |
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Conteúdo: |
hane into hydrocarbons using photoelectrochemical routes is attractive from a sustainability point of view owing to the possibility of using renewable energy (i.e., solar illumination) to activate this stable molecule. However, the process demands the development of novel catalysts that can promote methane activation and oxidation in a controlled manner to increase energy conversion efficiency. Herein, we demonstrated that semiconductor heterostructures improved charge separation compared to the individual materials alone. A more effortless transfer between bands favors the separation of the electron-hole (e− /h+) pairs generated by the photoelectrocatalytic system and prevents them from recombining. This process produces reactive oxygens, essential to driving methane oxidation conversion of the C?H bond cleavage. TiO2:SnO2 semiconductor heterojunction catalysts in film shape were investigated for methane oxidation via a photoelectrocatalytic process. The methane oxidation reactions were carried out in an inflow and sealed electrochemical system for 1 h. Liquid-state nuclear magnetic resonance revealed methanol and acetic acid as the main liquid products, where the TiO2:SnO2 heterojunction exhibited better performance with values of 30 and 8 µmol. cm− 2 .h− 1 , respectively. Compared to their materials alone, the superior performance of the TiO2:SnO2 heterojunction is attributed to the formation of heterostructure type II that enables a more effortless transfer between bands, facilitating the separation of the generated e− /h+ pairs under UV-Vis irradiation. The outcomes achieved here will motivate further studies for developing semiconductor heterojunction structure catalysts in photoelectrocatalysis to partially oxidize methane into valuable chemicals. Menoshane into hydrocarbons using photoelectrochemical routes is attractive from a sustainability point of view owing to the possibility of using renewable energy (i.e., solar illumination) to activate this stable molecule. However, the process demands the development of novel catalysts that can promote methane activation and oxidation in a controlled manner to increase energy conversion efficiency. Herein, we demonstrated that semiconductor heterostructures improved charge separation compared to the individual materials alone. A more effortless transfer between bands favors the separation of the electron-hole (e− /h+) pairs generated by the photoelectrocatalytic system and prevents them from recombining. This process produces reactive oxygens, essential to driving methane oxidation conversion of the C?H bond cleavage. TiO2:SnO2 semiconductor heterojunction catalysts in film shape were investigated for methane oxidation via a photoelectrocatalytic process. The methane oxidation reactions were carried out in an inflow and sealed electrochemical system for 1 h. Liquid-state nuclear magnetic resonance revealed methanol and acetic acid as the main liquid products, where the TiO2:SnO2 heterojunction exhibited better performance with values of 30 and 8 µmol. cm− 2 .h− 1 , respectively. Compared to their materials alone, the superior performance of the TiO2:SnO2 heterojunction is attributed to the formation of heterostructure type II that enables a more effortless tran... Mostrar Tudo |
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Palavras-Chave: |
CH4 oxidation; Methane oxidation; Photoelectrocatalysis; TiO2 SnO2 heterojunction. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 02695naa a2200289 a 4500
001 2157017
005 2023-10-02
008 2023 bl uuuu u00u1 u #d
022 $a0925-8388
024 7 $ahttps://doi.org/10.1016/j.jallcom.2023.172090$2DOI
100 1 $aSILVA, R. M. e
245 $aThe role of TiO2$bSnO2 heterojunction for partial oxidation of methane by photoelectrocatalytic process at room temperature.$h[electronic resource]
260 $c2023
300 $a7 p.
520 $ahane into hydrocarbons using photoelectrochemical routes is attractive from a sustainability point of view owing to the possibility of using renewable energy (i.e., solar illumination) to activate this stable molecule. However, the process demands the development of novel catalysts that can promote methane activation and oxidation in a controlled manner to increase energy conversion efficiency. Herein, we demonstrated that semiconductor heterostructures improved charge separation compared to the individual materials alone. A more effortless transfer between bands favors the separation of the electron-hole (e− /h+) pairs generated by the photoelectrocatalytic system and prevents them from recombining. This process produces reactive oxygens, essential to driving methane oxidation conversion of the C?H bond cleavage. TiO2:SnO2 semiconductor heterojunction catalysts in film shape were investigated for methane oxidation via a photoelectrocatalytic process. The methane oxidation reactions were carried out in an inflow and sealed electrochemical system for 1 h. Liquid-state nuclear magnetic resonance revealed methanol and acetic acid as the main liquid products, where the TiO2:SnO2 heterojunction exhibited better performance with values of 30 and 8 µmol. cm− 2 .h− 1 , respectively. Compared to their materials alone, the superior performance of the TiO2:SnO2 heterojunction is attributed to the formation of heterostructure type II that enables a more effortless transfer between bands, facilitating the separation of the generated e− /h+ pairs under UV-Vis irradiation. The outcomes achieved here will motivate further studies for developing semiconductor heterojunction structure catalysts in photoelectrocatalysis to partially oxidize methane into valuable chemicals.
653 $aCH4 oxidation
653 $aMethane oxidation
653 $aPhotoelectrocatalysis
653 $aTiO2 SnO2 heterojunction
700 1 $aSOUZA, F. L.
700 1 $aDIAS, E.
700 1 $aSILVA, G. T. S. T. da
700 1 $aDÚRAN, F. E.
700 1 $aREGO, A.
700 1 $aHIGGINS, D.
700 1 $aRIBEIRO, C.
773 $tJournal of Alloys and Compounds$gv. 968, 172090, 2023.
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