We have theoretically studied the stability and reconstruction of (111) surfaces of Au, Pt, and Cu. We have calculated the surface energy, surface stress, interatomic force constants, and other relevant quantities by ab initio electronic structure calculations using the density functional theory (DFT), in a slab geometry with periodic boundary conditions. We have estimated the stability towards a quasi-one-dimensional reconstruction by using the calculated quantities as parameters in a one-dimensional Frenkel-Kontorova model. On all surfaces we have found an intrinsic tensile stress. This stress is large enough on Au and Pt surfaces to lead to a reconstruction in which a denser surface layer is formed, in agreement with experiment. The experimentally observed differences between the dense reconstruction pattern on Au(111) and a sparse structure of stripes on Pt(111) are attributed to the details of the interaction potential between the first layer of atoms and the substrate.
Sample of nonmagnetic fraction of fly ash "Nikola Tesla-B" power station was used for zeolite synthesis experiment Quartz and amorphous phase as aluminosilicate glass were main phases in this sample. After zeolitization under some hydrothermal conditions in the new product were also detected quartz and new phases A zeolite and some amount of hydroxysodalite. IR and XRD methods were used to determine phases present in the starting and zeolitic material.
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