怀孕期头发中一些元素含量的变化趋势

用同步辐射激发X射线荧光分析,对11个产妇怀孕期间头发内一些元素含量的变化趋势进行了测量,在各自对比的基础上,得到了一些结果。     

Electrophysical properties of oligomer-polymer complexes based on heat-resistant oligoaryleneamines

Oligoaryleneamines of different structures are synthesized. Their thermal characteristics are studied. Oligomer-polymer complexes are obtained based on these oligomers, and their structures are identified. The interaction in an aromatic oligobase-polyacid system is investigated with the use of spectrophotometry. It is shown that these structures have an exponential dependence of specific electroconductivity on temperature.     

Adhesion of polymers: New approaches to determination of surface properties of metals

Determination of the acid-base properties of metal surfaces used as substrates in adhesive compounds was performed by a two-liquid method. It was shown that the suggested method provides a possibility of scientifically grounded selection of a substrate for creating adhesive polymeric-adhesive-metal compounds with a high level of interphase acid-base interaction.     

Interaction of adhesives in metal-polymer systems in acid-base approach

A comparative analysis of different methods of evaluating the surface energy and acid-base characteristics of solid smooth polymer surfaces is carried out. It is founded that the surfaces of many studied polymers have low energy and are characterized by low values of acidity parameters; furthermore, their acidbase properties are significantly affected by the preparation of the surface (time and temperature of extrusion, etc.). It is shown that the acid-base approach makes it possible to find the optimum concentration for the makeups of composite materials with specified properties.     

On the enhancement of M1-transitions from neutron resonances in the Ba and Ce isotopes

The M1-strength functions for transitions from the ground states of ^136,138Ba and ¹⁴⁰Ce to the states lying near the neutron binding energy B_n are calculated within the quasiparticle-phonon nuclear model. The calculated M1-strength functions describe well the relevant experimental data. It is shown that a notable enhancement of the M1-transitions is caused by the proximity of the maximum of the M1-resonance to B_n. As a result the intensities of the E1 and M1-transitions appear to be close to each other.     

Core polarization for M2 transitions in odd-A tin isotopes

The reduced M2 transition probabilities $\text{11}\text{2}{}^{\mathrm{?}}{}_1\text{→}\text{7}\text{2}{}^{\mathrm{+}}{}_1$ in the odd-A isotopes ^109–121Sn are found to reveal a specific behaviour. B(M2) values are calculated in the framework of the quasiparticlephonon model. The coupling of a quasineutron with the 2⁺, 3^? and 2^? one-phonon core excitation is taken into account. Inclusion of all one-phonon 2^? states up to 24 MeV in the wave functions of the excited states $\text{11}\text{2}{}^{\mathrm{?}}{}_1\text{and}\text{7}\text{2}{}^{\mathrm{+}}{}_1$ reduces the theoretical B(M2) values by 3–4 times as compared to the single-particle values. The specific B(M2) dependence on the mass number appears to be due to the pairing effect.