The temperature anomalies of the YBa₂Cu₃O_6.9 charge carriers density from 290 K to Tc

A possibility of HTSC electronic properties investigating by means of measuring the electrical resistance r_C of HTSC/normal metal interface is grounded. An existence of the correlations between anomalies of r_C and anomalies of density nf of HTSC charge carriers is shown. The correlations between the anomalies of dependence r_C(T) for interface YBa₂Cu₃O_6.9/In and anomalies of temperature dependences of YBa₂Cu₃O_6.9 lattice cell parameters b and c are demonstrated. The conclusion is made that the reason of anomalies r_C at T>>TC is pairing the hole charge carriers of YBa₂Cu₃O_6.9 to positive bosons. Sharp and deep r_C-anomaly before n-s-transition correlates to well-known sign-reversal effect of Hall coefficient. It is explained by bosons disintegration and posterior intensive conversion of hole carriers to electrons