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International audience; A new simulation of Venus atmospheric circulation obtained with the LMD Venus GCM is described and the simulated wave activity is analysed. Agreement with observed features of the temperature structure, static stability and zonal wind field is good, such as the presence of a cold polar collar, diurnal and semi-diurnal tides. At the resolution used (96 longitudes × 96 latitudes), a fully developed superrotation is obtained both when the simulation is initialised from rest and from an atmosphere already in superrotation, though winds are still weak below the clouds (roughly half the observed values). The atmospheric waves play a crucial role in the angular momentum budget of the Venus’s atmospheric circulation. In the upper cloud, the vertical angular momentum is transported by the diurnal and semi-diurnal tides. Above the cloud base (approximately 1 bar), equatorward transport of angular momentum is done by polar barotropic and mid- to high-latitude baroclinic waves present in the cloud region, with frequencies between 5 and 20 cycles per Venus day (periods between 6 and 23 Earth days). In the middle cloud, just above the convective layer, a Kelvin type wave (period around 7.3 Ed) is present at the equator, as well as a low-latitude Rossby-gravity type wave (period around 16 Ed). Below the clouds, large-scale mid- to high-latitude gravity waves develop and play a significant role in the angular momentum balance.

Accepted: 2013-10-08, 資料番号: SA1004601000

Exfoliated carbon fibers (ExCFs) obtained through rapid heat-treatment of intercalation compounds of carbon fibers had changed to the bundle of thin filament. In one of applications of its ExCFs, it was tried to nanocomposite where the application of Carbon nano tube (CNT) made an attempt. Preparation of composite using Nylon 6 and the ExCFs as the matrix and fillers was carried out by the injection molding. As the result, it became clear that addition of the ExCFs as fillers could be reinforced the matrix. Bending stress and elastic modulus of composite reinforced by the ExCFs increased around 50% with increasing in addition of the ExCFs in comparison with blank. It became clear that the ExCFs also exhibited better field emission characteristic at small-applied voltage in the case of an electrode material of field emission display (FED). Its field emission characteristics surpassed the case which CNT was applied to the electrode. Future applications were expected to the ExCFs.