Search for: All records

This study reports the longitudinal dependence of the field‐aligned Poynting flux in the Northern Hemisphere (NH) based on 11 years' (1999–2009) observations at ∼800 km altitude by the Defense Meteorological Satellite Program (DMSP) F13 satellite. Seasonal variations of the longitudinal distributions of the Poynting flux in both geographic and geomagnetic coordinates were statistically investigated. The net Poynting flux, which is the sum of downward and upward fluxes, is downward and peaks in the magnetic local time pre‐noon sector and near the geomagnetic pole. In geographic coordinates there is a longitudinal peak of the net Poynting flux that occurs between ∼130° and 160°W. The net Poynting flux is, in general, stronger in the western hemisphere than in the eastern hemisphere and larger in summer than in winter. These results indicate that the magnetospheric energy deposition into the northern polar upper atmosphere has obvious longitudinal and seasonal variations.

An efficient CuPd nanoparticle (NP) catalyst (3 nm CuPd NPs deposited on carbon support) is designed for catalyzing electrochemical allylic alkylation in water/isopropanol (1:1 v/v) and 0.2 mKHCO₃solution at room temperature. The Pd catalysis was Pd/Cu composition‐dependent, and CuPd NPs with a Pd/Cu ratio close to one are the most efficient catalyst for the selective cross‐coupling of alkyl halides and allylic halides to form C−C hydrocarbons with product yields reaching up to 99 %. This NP‐catalyzed electrochemical allylic alkylation expands the synthetic scope of cross‐coupling reactions and can be further extended to other organic reaction systems for developing green chemistry electrosynthesis methods.

An efficient CuPd nanoparticle (NP) catalyst (3 nm CuPd NPs deposited on carbon support) is designed for catalyzing electrochemical allylic alkylation in water/isopropanol (1:1 v/v) and 0.2 mKHCO₃solution at room temperature. The Pd catalysis was Pd/Cu composition‐dependent, and CuPd NPs with a Pd/Cu ratio close to one are the most efficient catalyst for the selective cross‐coupling of alkyl halides and allylic halides to form C−C hydrocarbons with product yields reaching up to 99 %. This NP‐catalyzed electrochemical allylic alkylation expands the synthetic scope of cross‐coupling reactions and can be further extended to other organic reaction systems for developing green chemistry electrosynthesis methods.