Bohatá rodina forem, ve kterých se vyskytuje uhlík, se nedávno rozrostla o nový a velmi zajímavý systém - grafen (angl. graphene). K obecně známému grafitu a diamantu a k nedávno objeveným a intenzivně studovaným uhlíkovým nanotrubkám a fullerenům tak přibyl první dvojdimenzionální alotrop uhlíku. Jeho příprava před několika lety odstartovala ve fyzice pevných látek nebývalou a stále trvající vlnu zájmu, srovnatelnou snad jen s objevem vysokoteplotní supravodivosti nebo kvantového Hallova jevu., Milan Orlita., and Obsahuje bibliografii
During the General Assembly of the European Geosciences Union in April 2008, the new Earth Gravitational Model 2008 (EGM08) was released with fully-normalized coefficients in the spherical harmonic expansion of the Earth's gravitational potential complete to degree and order 2159. EGM08 is based on inverse modeling methods that rely on data observed both on the Earth's surface and in space. Forward modeling equations based on Newtonian integrals can be converted into series forms that are compatible with the spherical harmonic description of the geopotential. Namely gravitational potentials of ocean water (fluid masses below the geoid) and topographical masses (solid masses above the geoid) can be formulated and evaluated numerically through spherical harmonic expansions. The potential constituents as well as their radial derivatives can be used for a step known in geodesy and geophysics as gravity field reduction or stripping. Reducing EGM08 for these constituents can help to analyze the internal structure of the Earth (geophysics) as well as to derive the Earth's gravitational field harmonic outside the geoid (geodesy)., Pavel Novák., and Obsahuje bibliografii
The activity of 194 neurons was recorded in three subdivisions of the medial geniculate body (74 neurons in the ventral, 62 in the medial and 44 neurons in the dorsal subdivision, i.e. vMGB, mMGB and dMGB) of guinea pigs anesthetized with ketamine-xylazine. The discharge properties of neurons were evaluated by means of peristimulus time histograms (PSTHs), interval histograms (INTHs) and auto-correlograms (ACGs). In the whole MGB, the most frequent PSTH responses to pure tone stimuli were onset (43 %) or chopper (32 %). The onset responses were mostly present in the vMGB, whereas chopper responses dominated in the dMGB. In the whole MGB Poisson-like and bimodal INTHs were found in 46 % and 40 % of neurons, respectively. The mMGB revealed fewer bimodal and more symmetrical types of INTH. In the whole MGB, 60 % of units were found to have ACGs typical for short bursts (<100 ms), 23 % for long bursts (>100 ms) and 15 % of units fired without bursts. Neurons in the vMGB were characterized by short bursting, whereas those in the mMGB and dMGB expressed more activity in the long bursts. The results demonstrate that the type of information processing in the vMGB, which belongs to the ”primary” auditory system, is different from that in two other subdivisions of the MGB., E. Kvašňák, J. Popelář, J. Syka., and Obsahuje bibliografii