Sur les propriétés magnétiques de l'adénosine triphosphate (ATP) et de ses constituants

A detailed thermomagnetic study (80°–380°K) has been made on polycrystalline adenosine triphosphate (disodium salt), hydrated, dried, compressed and deeply cooled. The susceptibility-temperature curves exhibit around 180°K an abrupt transition from the Curie paramagnetismχ?χ ₀=CT ^?1,C=1.37·10^?5 cm³ g^?1°K, to a state, which most frequently is a temperature independent paramagnetism of the order of 10^?7 cm³ g^?1 (extremely weak ESR absorption at room temperature according toIsenberg andSzent-Györgyi). The Curie paramagnetism might be related to the acceptor-donor process of charge transfer imagined bySzent-Györgyi to explain the energetic comportment of ATP. Extensive thermomagnetic study of adenosine, KH₂PO₄ and KD₂PO₄ was made. Using a simple model based on these data we have constructed susceptibility-temperature curves for ATP di-Na which approximate the real behaviour fairly well.     

On multiply periodic real functions: An addendum

In [1] a definition of multiple periodicity has been given that intuitively seemed to be obvious, but it does not cover all cases of periodicity which cannot be considered as simple periodicity. This paper extends the basic definition of multiple periodicity and consequently completes the proof of some theorems.     

Spectroscopy of highly excited states in29Si

Particleγ-ray coincidences have been measured in the²⁸Si (d,pγ) reaction at 6.5 and 7 MeV bombarding energy, in the²⁶Mg (α,nγ) reaction at 12, 14 and 15 MeV, and in the²⁷A1 (τ,pγ) reaction at 9 MeV. Theγ-decay has been observed for all bound states of²⁹Si and for 56 unbound states up to 12,960 KeV excitation energy. Particleγ-ray angular correlations were measured in the²⁸Si (d,pγ) reaction at 6.5 MeV and in the²⁶Mg (α,nγ) reaction at 12 MeV. Spin (-parity) assignments or restrictions were obtained for nearly all bound states and some high-spin states above the binding energy. The assignment of mirror levels in²⁹Si and²⁹P has been extended to 8.2 MeV excitation energy. The excitation energies of 41 positive-parity states are reproduced by shell model calculations. The possible existence of aK ^π=5/2⁺ band with prolate deformation is discussed.     

Stress effect on the magnetoresistance of amorphous ferromagnets

To investigate the magnetization in amorphous ferromagnetic alloys we measured the change in the magnetoresistance (H⊥j and H 6j) simultaneously applying a tensile stress along the direction of the ribbons. With increasing stress we observed a complete alignment of the magnetic domain vectors M_s parallel andantiparallel (for λ_s > 0) or perpendicular (for λ_s < 0) to the stress axis. It is found that on average a value of σ_s = 10 kg/mm² is sufficient in all measured samples to produce this effect. The change in the magnetoresistance by stress annealing indicates that a preferred domain orientation in stress direction is induced.     

Surface decoration: Localization of crystallites along the steps

The interest of decorating surfaces by metallic particles is to point out defects and in particular, steps. However, the precise localization of these particles is not known. It is shown here, by statistical measurements, that gold and palladium nuclei settle in the upper part of diatomic and monoatomic steps of (100) KCl. This unexpected localization is interpreted by the consideration of the elastic strain field, induced in the substrate by an in-contact crystallite. A crystallite placed near to the lower part of a step finds itself in a repulsive situation. When localized in the upper part, an attractive force counterbalanced by the line tension of the step exists. It is understood that decorating crystallites moving along the steps do not leave them, as it has been revealed by measurements and observations.     

Scattering spherical voids in nanocrystalline TiO2- enhancement of efficiency in dye-sensitized solar cells

Spherical voids as light scattering centers in nanocrystalline TiO2 films were realized with polystyrene particles of diameter 400 nm, thus enhancing the photovoltaic performance by 25% on large areas, as well as providing an indication that these films can be used with electrolytes of higher viscosity.     

Coulometric titration with quinquevalent uranium determination of vanadium(v)

Variadium(V) has been determined by reduction with generated uranium(V) with an accuracy of about ± 0.3%. Amounts as small as 15 μg were successfully titrated. The suggested ph range is 1–2.5. Iron(III) is reduced simultaneuosly with vanadium(V).