We analyse the quasar two‐point correlation function (2pCF) within the redshift interval 0.8 < z < 2.2 using a sample of 52 303 quasars selected from the recent Sloan Digital Sky Survey Data Release 7. Our approach to the 2pCF uses the concept of a local Lorentz (Fermi) frame, for the determination of the distance between objects, and the permutation method of random catalogue generation. Assuming a spatially flat cosmological model with ΩΛ= 0.726, we have found that the real‐space 2pCF is fitted well with the power‐law model within the distance range 1 < σ < 35 h−1 Mpc with the correlation length r0= 5.85 ±  0.33 h−1 Mpc and the slope γ= 1.87 ±  0.07. The redshift‐space 2pCF is approximated with s0= 6.43 ±  0.63 h−1 Mpc and γ= 1.21 ±  0.24 for 1 < s < 10 h−1 Mpc, and s0= 7.37 ±  0.81 h−1 Mpc and γ= 1.90 ±  0.24 for 10 < s < 35 h−1 Mpc. For distances s > 10 h−1 Mpc, the parameter describing the large‐scale infall to density inhomogeneities is β= 0.63 ±  0.10 with the linear bias b = 1.44 ±  0.22, which marginally (within 2σ) agrees with the linear theory of cosmological perturbations. We discuss possibilities to obtain a statistical estimate of the random component of quasar velocities (different from the large‐scale infall). We note a slight dependence of the quasar velocity dispersion upon the 2pCF parameters in the region r < 2 Mpc.

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We present a new approach to the composite spectra construction based on stacking spectra with similar slopes α λ within the wavelength range redward of Lyα emission line, which allows to reduce the typical noise. With the help of this technique a detailed study of the HI Lyα-forest region (λ rest ≈ 1050 − 1200 Å) of the own sample of 3439 medium-resolution quasar spectra from SDSS DR7 was performed. More than 14 lines were found within this wavelength range, three of which were known from previous studies of quasar composite spectra from SDSS and some others were known in composite spectra from space-based telescopes or high-resolution spectra of individual quasars from ground-based telescopes.