Asymmetry of the normal zone propagation velocity in superconductors

The thermoelectric mechanism of the asymmetrical velocity of normal zone propagation in superconductors, relative to the direction of the transport current is suggested. The difference of the normal-superconducting interface velocities parallel and anti-parallel to the current direction due to this mechanism is of the order of 1 – 50 cm s^?1 for different metals. The thermoelectric effect (Thomson heat) has a hysteresis which occurs opon destruction (or restoration) of superconductivity in the sample with respect to the transport current.     

The effect of nitrate and nitrite on the respiration and cytochrome system of Rhizobium lupini]

Chromosome replication has been analysed in four species of Chilocorus. In C. ORBUS Csy., C. tricyclus Smith, and C. hexacyclus Smith, centric regions of all chromosomes are last to replicate, preceded in order by heterochromatic arms and euchromatic arms. In C. stigma Say, very late replication of centric regions can be detected only in otherwise wholly euchromatic chromosomes (= monophasics); in chromosomes with one arm heterochromatic ( = disphasics), these arms are last to replicate. Based on pachytene bivalent morphology and chromosome banding patterns, and supported by autoradiographic data, models are presented for the general organisation of Chilocorus chromosomes. All chromosomes in the first three species are subdivided into euchromatic arm, centric heterochromatin, and either a second euchromatic are (monophasics) or a heterochromatic arm (diphasics). Chilocorus stigma diphasics apparently lack distinct centric organisation, and are therefore divided into euchromatic and heterochromatic arms only.