Accumulation of PAHs in Tundra Plants and Soils under the Influence of Coal Mining

<p>Polycyclic aromatic hydrocarbon (PAH) concentrations in soils and plants in the Bolshezemelskaya tundra have been investigated at the sites affected by coal mining in comparison with the control ecosystems. Contribution of individual plant species to the total PAH accumulation is based on plant biomass data. In shrub tundra communities, the highest PAH concentrations are found in Pleurozium schreberi moss due to its high biomass and ability for active PAH accumulation. This species can be used for ecological monitoring of PAHs concentrations in the tundra communities. Light PAHs are more abundant in soils, plants of both contaminated and control sites as well as in the coal. But the highest excesses of PAH content in comparison with the control values are found for the high-molecular-weight PAHs due to their minimal concentration at the control site. Research on PAH accumulation in the organs of plants has revealed that polyarenes had fallen on the shrubs surfaces from the atmosphere and get accumulated in the plant superficial tissues without further penetration. Deciduous plant species accumulate more PAHs in leaves than evergreen shrubs do. Plants of herbal life form accumulate PAHs mainly from soil.</p

Оптимизация амплитуды магнитоупругих колебаний в ферритовой пластине

The maximum amplitudes of elastic vibrations, depending on the material parameters and parameters of external fields in a normally magnetized anisotropic magnetic plate at its excitation by radio frequency magnetic field were obtained. For this purpose we used the method "simulated annealing". The three- dimensional graphics of resonant surfaces of elastic oscillations on the thickness of the plate, on the elastic constants, magnetic damping constant and the magnetoelastic constant in the area of maximum amplitudes found by the simulated annealing algorithm were constructed and explainedНайдены максимумы амплитуд упругих колебаний в зависимости от материальных констант и параметров постоянного и переменного магнитных полей в нормально намагниченной анизотроп- ной ферритовой пластине при ее возбуждении радиочастотным магнитным полем. Для решения этой задачи использован алгоритм "имитация отжига". Построены и объяснены трехмерные графики резонансных поверхностей упругих колебаний в зависимости от толщины пластины, упругих констант, параметра магнитной диссипации и значений констант магнитоупругости в области максимальных амплитуд колебани