Nonlinear single-electron tunneling through individually coated colloid particles at room temperature

Single-electron tunneling (SET) has been observed with nanometer coated colloid gold particles at room temperature. We have made the smallest (3-nm) thiol- and silicon dioxide (SiO2)-coated gold particles, from which we obtained SET signals using a scanning tunneling microscope (STM)images reveal individual particles supported by an atomically flat metal surface. The STM tip is used to obtain SET signals from the individual particles, whose shapes have been characterized. The current-voltage curves of the particles exhibit well-defined Coulomb staircases that resemble those obtained at 4.2 K, indicating a strong Coulomb repulsive interaction at room temperature. The clear Coulomb staircases are due to a nonlinearity in the current steps. We suggest a possible mechanism for the nonlinearity in terms of many-body excitations in the particle. We have also identified the region of the particles, where the SET signal originates, using current-imaging-tunneling spectroscopy. We describe the advantages of using the coated nanometer particles for making devices for room-temperature operations

A reconstruction of the past trend of atmospheric CO based on firn air samples from Berkner Island, Antarctica

International audienceAlthough for several atmospheric trace gases trends over the past 100 year have been reconstructed using firn air analyses, little is known about one of the chemically most significant trace gases, namely CO. Among the 3 Antarctic drilling expeditions reported, the one from Berkner Island appears to have given results of sufficient analytical quality to warrant a modelling with the aim to reconstruct past changes in atmospheric CO. Based on our reconstructions, CO in high latitudes of the Southern Hemisphere has been increasing since beginning of the 20th century from ~38 ppbv to a recent value of about 52.5 ppbv. The increase in CO is mainly explained by the known increase in CH4, with biomass burning output being most likely responsible for an additional increase. Which, if any, role changes in OH have played cannot be derived

Autoinflation for otitis media with effusion (OME) in children

Objectives: This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the effects (benefits and harms) of autoinflation for otitis media with effusion (OME) in children

Antibiotics for otitis media with effusion (OME) in children

Objectives: This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the effects (benefits and harms) of oral antibiotics for otitis media with effusion (OME) in children

Adenoidectomy for otitis media with effusion (OME) in children

OBJECTIVES: This is a protocol for a Cochrane Review (intervention). The objectives are as follows:. To assess the effects (benefits and harms) of adenoidectomy, either alone or in combination with ventilation tubes (grommets), for otitis media with effusion (OME) in children

Topical and oral steroids for otitis media with effusion (OME) in children

Objectives: This is a protocol for a Cochrane Review (intervention). The objectives are as follows:. To assess the effects (benefits and harms) of topical and oral steroids for otitis media with effusion (OME) in children