Results 11 to 20 of about 41,593 (161)

Recent Advances with Biomass‐Derived Carbon‐Based Catalysts for the High‐Efficiency Electrochemical Reduction of Oxygen to Hydrogen Peroxide

Advanced Energy and Sustainability Research, Volume 4, Issue 12, December 2023., 2023
Electrocatalysts based on self‐doped heteroatomic carbon, derived from abundant and cheap biomass, have emerged as attractive candidates for H2O2 production by electrocatalysis, and this process is on‐site, decentralized, and environmentally friendly. Importantly, the conversion of biomass waste into high‐value‐added electrocatalysts is beneficial to ...
Yuan Wang, Haihong Zhong, Weiting Yang, Yongjun Feng, Nicolas Alonso-Vante   +4 more
wiley   +1 more source

Quantitative analysis of diurnal CO2 flux variations above an alkaline playa

Vadose Zone Journal, Volume 22, Issue 6, November/December 2023., 2023
Abstract The alkaline playas at Atlin, BC, provide a unique opportunity for studying the carbonate–bicarbonate system and carbonate mineral stability at the Earth's surface. In this study, dynamic closed chambers (DCCs) and pore‐gas sampling were used to directly quantify carbon dioxide (CO2) emission rates and characterize processes governing the CO2 ...
Anne‐Martine Doucet, Frances Jones, Katherine E. Raymond, Gregory Dipple, Thomas Andrew Black, Bethany Ladd, Klaus Ulrich Mayer   +6 more
wiley   +1 more source

Palladium‐ and Iridium‐Catalyzed Deracemization of Allylic Oxygen Compounds with Oxygen Nucleophiles

European Journal of Organic Chemistry, Volume 2022, Issue 44, November 25, 2022., 2022
Allylic oxygen compounds are versatile building blocks in natural and non‐natural product synthesis. This review describes the deracemization of racemic allylic oxygen compounds through palladium‐ and iridium‐catalyzed dynamic kinetic asymmetric transformation (DYKAT) with oxygen nucleophiles.
Hans‐Joachim Gais
wiley   +1 more source

C-, Sr-isotope stratigraphy of carbonate rocks from the Southern Espinhaço Ridge, Minas Gerais, southeastern Brazil

Anais da Academia Brasileira de Ciências, 2014
Neoproterozoic carbonate rocks comprise different stratigraphic units in the southern part of the Espinhaço Ridge, Minas Gerais, Brazil. C, O- and Sr-isotope analyses were carried out along four selected stratigraphic sections across these formations ...
LUCIO M.S. FRAGA, SORAYA C. NEVES, ALEXANDRE UHLEIN, ALCIDES N. SIAL, MARCIO M. PIMENTEL, ADOLF H. HORN   +5 more
doaj   +1 more source

Modelamiento de Procesos en la depositación de Carbonatos, Plataforma Marion Norte y Sur del Mioceno

FIGEMPA, 2018
Marion Plateau es una plataforma de carbonatos fría-subtropical, ubicada al noroeste, costa afuera de Australia. Tiene dos plataformas separadas que presentan diferentes biotas de carbonatos que fueron desarrolladas en etapas de crecimiento ...
Johanna Navarrete, Cedric John, Jairo Bustos, Diego Palacios, Marcelo Benítez   +4 more
doaj   +1 more source

Synthesis of a Metalla[2]catenane, Metallarectangles and Polynuclear Assemblies from Di(N‐Heterocyclic Carbene) Ligands

Angewandte Chemie, Volume 136, Issue 39, September 23, 2024.
The fluorenone‐bridged di‐NHC precursor H2‐1(PF6)2 reacts with Ag2O in CH3CN to give the [2]catenane [Ag4(1)4](PF6)4, which disintegrates in DMF into two metallarectangles [Ag2(1)2](PF6)2. Substitution of the imidazo[1,5a]pyridinium NHC precursors in H2‐1(PF6)2 for imidazolium groups yields di‐NHC precursors H2‐L(PF6)2 which react with Ag2O to yield ...
Jin‐Ping Chang, Ya‐Wen Zhang, Li‐Ying Sun, Le Zhang, F. Ekkehardt Hahn, Ying‐Feng Han   +5 more
wiley   +2 more sources

Characteristics, distribution and diagenetic stages of chert in the La Silla Formation (Lower Ordovician), Argentine Precordillera

Anais da Academia Brasileira de Ciências, 2009
The late Cambrian - late Tremadocian La Silla Formation is a carbonate unit of the eastern Precordillera in Argentina whose facies indicate a shallow platform environment. Until this moment, there were no studies that referred to the diagenetic evolution
Mariana M. Raviolo, José A. Barbosa, Virgínio H. Neumann   +2 more
doaj   +1 more source

Los carbonatos marinos aptienses del anticlinal de Santillana del Mar. Cantabria: Procesos diagenéticos y su relación con los contenidos en Sr. Fe y Mn

Estudios Geologicos, 1990
En este trabajo se hace un estudio de los contenidos en Sr, Fe y Mn en los carbonatos del Cretácico inferior del anticlinal de Santillana del Mar, Cantabria. Las rocas carbonáticas estudiadas incluyen calizas, dolomías y dolomías dedolomitizadas.
M. Bustillo, R. Fort
doaj   +1 more source

Distribution of shallow water soft and hard bottom seabeds in the Isla del Coco National Park, Pacific Costa Rica

Revista de Biología Tropical, 2012
Geographic Information Systems (GIS) applications used in marine habitats are powerful tools for management and monitoring of marine reserves and resources.
Jeffrey A. Sibaja-Cordero, Jesús S. Troncoso, Catalina Benavides-Varela, Jorge Cortés   +3 more
doaj   +2 more sources

Estudos mecanísticos da hidrólise de ésteres carbonatos catalisada por imidazol.

Semina: Ciências Exatas e Tecnológicas, 2004
Foram examinados aspectos cinéticos e mecanísticos da hidrólise de  carbonatos de p-X-fenil p-nitrofenila (X = MeO,  Me,  H,   CI,   CN,  N02,   série   I)   e   carbonatos    de    bis-(p-X-fenila)  (X = MeO, Me,  H,  CI, NO, série II),    catalisada ...
Paulo Meneghelli, Carlos A Silva Perez, Olívio Fernandes Galão, Luciana Meneghelli, Maria Juliane Beraldo   +4 more
doaj   +1 more source