[en] It is shown that each Dirichlet polynomial P of degree N which is bounded in a certain natural Euclidean norm, admits a nontrivial uniform approximation on the corresponding interval on the real axis by a Dirichlet polynomial with spectrum containing significantly fewer than N elements. Moreover, this spectrum is independent of P. Bibliography: 19 titles.

[en] This is an investigation of the problem of the asymptotic distribution of the Frobenius numbers of n relatively prime integers. For n=3 virtually definitive results are obtained. For n>3 it is shown that the distributions appearing form a compact set. An essential role is played by the limit theorem for logarithms of denominators of continued fractions of random numbers.

[en] Surveillance no. 8 of Gravelines Power Plant take in account studies between November 1985 and October 1986. Hydrology, microbiology, phytoplankton, zooplankton, fishing, sub-tidal and intertidal benthos are studied. Evolutions of populations are joined with running of Power Plant which overtake maximum power 5576 MW during 1986. (authors)

[en] The ecological monitoring study of the fishing resources at the Gravelines site (Nord, France) aims at evaluating the natural variations of the main hydro-biological parameters and at analysing the potential impact of the Gravelines nuclear power plant on the marine environment and its resources. On the basis of samplings carried out between November 1986 and October 1987, impacts on hydrology, microbiology, phytoplankton, zooplankton, fisheries, intertidal and sub-tidal phyto-benthos and zoo-benthos are reported