Selected geomorphological problems of Mazovia

Celem artykułu jest zaprezentowanie charakterystycznych cech rzeźby wybranych obszarów Mazowsza ze szczególnym zwróceniem uwagi na jej uwarunkowania zarówno naturalne, jak i antropogeniczne. Przedstawiono holoceńskie zmiany w obrębie zbocza doliny Wisły na przykładzie Skarpy Ursynowskiej, zmiany w dnie doliny związane z osadnictwem olęderskim, wybrane aspekty budowy geologicznej i cechy rzeźby w okolicy Łubienicy na Wysoczyźnie Ciechanowskiej, morfologię zboczy i dna doliny dolnej Narwi w okolicy Łubienicy i Pułtuska oraz rekonstrukcję zmian środowiska przyrodniczego w okolicach Nasielska (od początku wczesnego średniowiecza po okres nowożytny).The main aim of the article is to present the landforms characteristics of the selected Mazovian areas with particular focus on its natural and anthropogenic conditions. This paper concerns the problems of: the Holocene changes within the Vistula River valley on the example of the the Ursynów Scarp development; the geomorphic changes in the bottom of the valley due to the Olęder settlements (the Kiełpińska Holm site), selected issues of geology and landscape evolution of the Ciechanowska Upland (The Lubienica-Superunki site), morphology of the slopes and of the Lower Narew Valley bottom near Łubienica and Pułtusk sites and the reconstruction of natural environment changes (from the early Middle Ages to the Early Modern Period) in the Nasielsk area

Structure of the hydroxyl groups and adsorbed D2OD_2O sites in the DX zeolite : DFT and experimental NMR data

We report on density functional theory computations combined with the results of measurements of the quadrupole coupling constants for 17O, hydroxyl deuterons, and adsorbed water deuterons in DX zeolite (n(Si)/n(Al) = 1). Calculations are performed for the crystalline periodic model of the DX zeolite. The local structural parameters are found for various oxygen positions at equilibrium. The quadrupole coupling constants for 17O are in the range CQ(17O) = 7.75 ± 0.5 and 3.75 ± 0.5 MHz for (Si–OD–Al) and (Si–O–Al) substructures, respectively. Related values of the asymmetry parameter η fall in the ranges of 0.9 ± 0.5 and 0.15 ± 0.1, respectively. The quadrupole coupling constant for deuterons depends on the OD distance according to the relation CQ(D)[MHz] = −2.732dOD[MHz/Å] + 2.938 MHz. Deuterons are assigned to labeled oxygen positions according to the decreasinng quadrupole coupling constant CQ(D) as O1 ≥ O4 > O2 > O3, with their relative abundances of 54.4, 7.6, 26.6, and 11.4%, respectively. The binding energy of deuteron in hydroxyl groups and for adsorbed water molecules is analyzed. Formation of the water hexamer in the plane of the 12-ring window was confirmed. Results of the calculations are compared with NMR experimental data for 17O and D