153 research outputs found
On the rate of Poisson approximation to partial sum processes
We investigate approximation of a Bernoulli partial sum process to the
accompanying Poisson process in the non-i.i.d. case. The rate of closeness is
studied in terms of the minimal distance in probability
Killing Spinor Equations from Nonlinear Realisations
Starting from a nonlinear realisation of eleven dimensional supergravity
based on the group G11, whose generators appear as low level generators of E11,
we present a super extended algebra, which leads to a covariant derivative of
spinors identical to the Killing spinor equation of this theory. A similar
construction leads to the Killing spinor equation of N=1 pure supergravity in
ten dimensions.Comment: 16 pages, typos correcte
Investigation of the microstructure, mechanical properties and thermal stability of nanocomposite coatings based on amorphous carbon
The Ti-C-Ni-Cr and Ti-C-Ni-Cr-Al-Si nanocomposite coatings based on amorphous carbon and the nanosized particles were synthesized by magnetron method. The results of the microstructure features and mechanical properties investigations of these coatings are presented. The thermal stability of microstructure and properties of these coatings at tempering up to 900Β°C were investigated. These coatings have a high (11β18 GPa) hardness, low (ΞΌ < 0.2) the coefficient of friction and high thermal stability of the microstructure and properties up to 700Β°C. The features of elastically stressed state of nanosized particles in these coatings were founded. A high local internal stresses in the TiC nanoscale particles do not observed
Thermal stability of Ti-C-Ni-Cr and Ti-C-Ni-Cr-Al-Si nanocomposite coatings
The results of the microstructure, mechanical and tribological properties investigations of Ti-C-Ni-Cr and Ti-C-Ni-Cr-Al-Si nanocomposite coatings based on amorphous carbon in the initial state and after the annealing to 900 Β°C are presented. The effect of annealing temperature on the microstructure, tribological and mechanical properties of Ti-C- Ni-Cr and Ti-C-Ni-Cr-Al-Si nanostructured coatings is discussed
Magneto-optic Kerr effect in a spin-polarized zero-moment ferrimagnet
The magneto-optical Kerr effect (MOKE) is often assumed to be proportional to
the magnetisation of a magnetically ordered metallic sample; in metallic
ferrimagnets with chemically distinct sublattices, such as rare-earth
transition-metal alloys, it depends on the difference between the sublattice
contributions. Here we show that in a highly spin polarized, fully compensated
ferrimagnet, where the sublattices are chemically similar, MOKE is observed
even when the net moment is strictly zero. We analyse the spectral ellipsometry
and MOKE of Mn 2 Ru x Ga, and show that this behaviour is due to a highly
spin-polarized conduction band dominated by one of the two manganese
sublattices which creates helicity-dependent reflectivity determined by a broad
Drude tail. Our findings open new prospects for studying spin dynamics in the
infra-red.Comment: 7 pages, 7 figure
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